diff --git a/KNOWNBUG b/KNOWNBUG
index 964674a..28a1091 100644
--- a/KNOWNBUG
+++ b/KNOWNBUG
@@ -38,13 +38,21 @@
    for the png_set_gAMA(), png_set_cHRM(), and corresponding png_get_()
    functions will be needed.
 
-4. September 1999 -- BUG --
+4. September 1999 -- BUG [FIXED] --
 
-   Portions of the new MMX code in pngvcrd.c are defined out because the
-   did not work properly.  When PNGVCRD_INTERLACE_BUG_IS_FIXED is defined,
-   to enable the code, pngtest pngtest.png pngout.png results in a
-   "Debug error! Damage before normal block # 57 at 0x007e19f0" on
-   a Pentium II with MMX system.  This seems to be caused by the heap
-   being trashed before a free() in png_read_destroy().
+   Portions of the new MMX code in pngvcrd.c were ifdef'd out because they
+   didn't work properly, but the bug appears to have been found and fixed.
+   As a result, all parts of the code are once again enabled.  If you think
+   there's still a problem, you can recompile with one of the following two
+   macros defined and see if the problem goes away:
 
-   When PNGVCRD_COMBINE_BUG_IS_FIXED is defined (what?)
+	DISABLE_PNGVCRD_COMBINE
+	DISABLE_PNGVCRD_INTERLACE
+
+   The second one is in the function where the bug was; as far as we are
+   aware, there was never any bug in the other function.  Please notify us
+   if you find any problems in libpng, regardless of whether the two macros
+   make any difference:  png-implement@ccrc.wustl.edu
+
+   Again, we believe the MMX code in pngvcrd.c is 100% correct, but it has
+   not yet been tested extensively.
diff --git a/pngvcrd.c b/pngvcrd.c
index 0e9248c..b159171 100644
--- a/pngvcrd.c
+++ b/pngvcrd.c
@@ -1,3836 +1,3824 @@
-/* pngvcrd.c - mixed C/assembler version of utilities to read a PNG file
- *
- * For Intel x86 CPU and Microsoft Visual C++ compiler
- *
- * libpng 1.0.4d - October 6, 1999
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998, Intel Corporation
- * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
- *
- * Contributed by Nirav Chhatrapati, Intel Corporation, 1998
- * Interface to libpng contributed by Gilles Vollant, 1999
- *
- */
-
-#define PNG_INTERNAL
-#include "png.h"
-
-#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD)
-
-static int mmx_supported=2;
-
-void
-png_read_filter_row_c(png_structp png_ptr, png_row_infop row_info,
-   png_bytep row, png_bytep prev_row, int filter);
-
-static int mmxsupport()
-{
-  int mmx_supported_local = 0;
-
-  _asm {
-    pushfd            //Save Eflag to stack
-    pop eax           //Get Eflag from stack into eax
-    mov ecx, eax      //Make another copy of Eflag in ecx
-    xor eax, 0x200000 //Toggle ID bit in Eflag [i.e. bit(21)]
-    push eax          //Save modified Eflag back to stack
-
-    popfd             //Restored modified value back to Eflag reg
-    pushfd            //Save Eflag to stack
-    pop eax           //Get Eflag from stack
-    xor eax, ecx      //Compare the new Eflag with the original Eflag
-    jz NOT_SUPPORTED  //If the same, CPUID instruction is not supported,
-                      //skip following instructions and jump to
-                      //NOT_SUPPORTED label
-
-    xor eax, eax      //Set eax to zero
-
-    _asm _emit 0x0f   //CPUID instruction  (two bytes opcode)
-    _asm _emit 0xa2
-
-    cmp eax, 1        //make sure eax return non-zero value
-    jl NOT_SUPPORTED  //If eax is zero, mmx not supported
-
-    xor eax, eax      //set eax to zero
-    inc eax           //Now increment eax to 1.  This instruction is
-                      //faster than the instruction "mov eax, 1"
-
-    _asm _emit 0x0f   //CPUID instruction
-    _asm _emit 0xa2
-
-    and edx, 0x00800000  //mask out all bits but mmx bit(24)
-    cmp edx, 0        // 0 = mmx not supported
-    jz  NOT_SUPPORTED // non-zero = Yes, mmx IS supported
-
-    mov  mmx_supported_local, 1  //set return value to 1
-
-NOT_SUPPORTED:
-    mov  eax, mmx_supported_local  //move return value to eax
-
-  }
-
-  //mmx_supported_local=0; // test code for force don't support MMX
-  //printf("MMX : %u (1=MMX supported)\n",mmx_supported_local);
-
-  return mmx_supported_local;
-}
-
-/* Combines the row recently read in with the previous row.
-   This routine takes care of alpha and transparency if requested.
-   This routine also handles the two methods of progressive display
-   of interlaced images, depending on the mask value.
-   The mask value describes which pixels are to be combined with
-   the row.  The pattern always repeats every 8 pixels, so just 8
-   bits are needed.  A one indicates the pixel is to be combined; a
-   zero indicates the pixel is to be skipped.  This is in addition
-   to any alpha or transparency value associated with the pixel.  If
-   you want all pixels to be combined, pass 0xff (255) in mask.  */
-
-/* Use this routine for x86 platform - uses faster MMX routine if machine
-   supports MMX */
-
-void
-png_combine_row(png_structp png_ptr, png_bytep row, int mask)
-{
-#ifdef DISABLE_PNGVCRD_COMBINE
-   int save_mmx_supported = mmx_supported;
-#endif
-
-   png_debug(1,"in png_combine_row_asm\n");
-
-#ifdef DISABLE_PNGVCRD_COMBINE
-   if ((png_ptr->transformations & PNG_INTERLACE) && png_ptr->pass != 6)
-       mmx_supported = 0;
-   else
-#endif
-      if (mmx_supported == 2)
-          mmx_supported = mmxsupport();
-
-   if (mask == 0xff)
-   {
-      png_memcpy(row, png_ptr->row_buf + 1,
-       (png_size_t)((png_ptr->width * png_ptr->row_info.pixel_depth + 7) >> 3));
-   }
-   /* GRR:  add "else if (mask == 0)" case?
-    *       or does png_combine_row() not even get called in that case? */
-   else
-   {
-      switch (png_ptr->row_info.pixel_depth)
-      {
-         case 1:
-         {
-            png_bytep sp;
-            png_bytep dp;
-            int s_inc, s_start, s_end;
-            int m;
-            int shift;
-            png_uint_32 i;
-
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
-            if (png_ptr->transformations & PNG_PACKSWAP)
-            {
-                s_start = 0;
-                s_end = 7;
-                s_inc = 1;
-            }
-            else
-#endif
-            {
-                s_start = 7;
-                s_end = 0;
-                s_inc = -1;
-            }
-
-            shift = s_start;
-
-            for (i = 0; i < png_ptr->width; i++)
-            {
-               if (m & mask)
-               {
-                  int value;
-
-                  value = (*sp >> shift) & 0x1;
-                  *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
-                  *dp |= (png_byte)(value << shift);
-               }
-
-               if (shift == s_end)
-               {
-                  shift = s_start;
-                  sp++;
-                  dp++;
-               }
-               else
-                  shift += s_inc;
-
-               if (m == 1)
-                  m = 0x80;
-               else
-                  m >>= 1;
-            }
-            break;
-         }
-
-         case 2:
-         {
-            png_bytep sp;
-            png_bytep dp;
-            int s_start, s_end, s_inc;
-            int m;
-            int shift;
-            png_uint_32 i;
-            int value;
-
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
-            if (png_ptr->transformations & PNG_PACKSWAP)
-            {
-               s_start = 0;
-               s_end = 6;
-               s_inc = 2;
-            }
-            else
-#endif
-            {
-               s_start = 6;
-               s_end = 0;
-               s_inc = -2;
-            }
-
-            shift = s_start;
-
-            for (i = 0; i < png_ptr->width; i++)
-            {
-               if (m & mask)
-               {
-                  value = (*sp >> shift) & 0x3;
-                  *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                  *dp |= (png_byte)(value << shift);
-               }
-
-               if (shift == s_end)
-               {
-                  shift = s_start;
-                  sp++;
-                  dp++;
-               }
-               else
-                  shift += s_inc;
-               if (m == 1)
-                  m = 0x80;
-               else
-                  m >>= 1;
-            }
-            break;
-         }
-
-         case 4:
-         {
-            png_bytep sp;
-            png_bytep dp;
-            int s_start, s_end, s_inc;
-            int m;
-            int shift;
-            png_uint_32 i;
-            int value;
-
-            sp = png_ptr->row_buf + 1;
-            dp = row;
-            m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
-            if (png_ptr->transformations & PNG_PACKSWAP)
-            {
-               s_start = 0;
-               s_end = 4;
-               s_inc = 4;
-            }
-            else
-#endif
-            {
-               s_start = 4;
-               s_end = 0;
-               s_inc = -4;
-            }
-            shift = s_start;
-
-            for (i = 0; i < png_ptr->width; i++)
-            {
-               if (m & mask)
-               {
-                  value = (*sp >> shift) & 0xf;
-                  *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                  *dp |= (png_byte)(value << shift);
-               }
-
-               if (shift == s_end)
-               {
-                  shift = s_start;
-                  sp++;
-                  dp++;
-               }
-               else
-                  shift += s_inc;
-               if (m == 1)
-                  m = 0x80;
-               else
-                  m >>= 1;
-            }
-            break;
-         }
-
-         case 8:
-         {
-            png_bytep srcptr;
-            png_bytep dstptr;
-            png_uint_32 len;
-            int m;
-            int diff, unmask;
-
-            __int64 mask0=0x0102040810204080;
-
-            if (mmx_supported)
-            {
-               srcptr = png_ptr->row_buf + 1;
-               dstptr = row;
-               m = 0x80;
-               unmask = ~mask;
-               len  = png_ptr->width &~7;  //reduce to multiple of 8
-               diff = png_ptr->width & 7;  //amount lost
-
-               _asm
-               {
-                  movd       mm7, unmask   //load bit pattern
-                  psubb      mm6,mm6       //zero mm6
-                  punpcklbw  mm7,mm7
-                  punpcklwd  mm7,mm7
-                  punpckldq  mm7,mm7       //fill register with 8 masks
-
-                  movq       mm0,mask0
-
-                  pand       mm0,mm7       //nonzero if keep byte
-                  pcmpeqb    mm0,mm6       //zeros->1s, v versa
-
-                  mov        ecx,len       //load length of line (pixels)
-                  mov        esi,srcptr    //load source
-                  mov        ebx,dstptr    //load dest
-                  cmp        ecx,0         //lcr
-                  je         mainloop8end
-
-mainloop8:
-                  movq       mm4,[esi]
-                  pand       mm4,mm0
-                  movq       mm6,mm0
-                  pandn      mm6,[ebx]
-                  por        mm4,mm6
-                  movq       [ebx],mm4
-
-                  add        esi,8         //inc by 8 bytes processed
-                  add        ebx,8
-                  sub        ecx,8         //dec by 8 pixels processed
-
-                  ja         mainloop8
-mainloop8end:
-
-                  mov        ecx,diff
-                  cmp        ecx,0
-                  jz         end8
-
-                  mov        edx,mask
-                  sal        edx,24        //make low byte the high byte
-
-secondloop8:
-                  sal        edx,1         //move high bit to CF
-                  jnc        skip8         //if CF = 0
-                  mov        al,[esi]
-                  mov        [ebx],al
-skip8:
-                  inc        esi
-                  inc        ebx
-
-                  dec        ecx
-                  jnz        secondloop8
-end8:
-                  emms
-               }
-            }
-            else /* mmx not supported - use modified C routine */
-            {
-               register unsigned int incr1, initial_val, final_val;
-               png_size_t pixel_bytes;
-               png_uint_32 i;
-               register int disp = png_pass_inc[png_ptr->pass];
-               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
-
-               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
-               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
-                  pixel_bytes;
-               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
-               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
-               final_val = png_ptr->width*pixel_bytes;
-               incr1 = (disp)*pixel_bytes;
-               for (i = initial_val; i < final_val; i += incr1)
-               {
-                  png_memcpy(dstptr, srcptr, pixel_bytes);
-                  srcptr += incr1;
-                  dstptr += incr1;
-               }
-            } /* end of else */
-
-            break;
-         }       // end 8 bpp
-
-         case 16:
-         {
-            png_bytep srcptr;
-            png_bytep dstptr;
-            png_uint_32 len;
-            int unmask, diff;
-            __int64 mask1=0x0101020204040808,
-                    mask0=0x1010202040408080;
-
-            if (mmx_supported)
-            {
-               srcptr = png_ptr->row_buf + 1;
-               dstptr = row;
-
-               unmask = ~mask;
-               len     = (png_ptr->width)&~7;
-               diff = (png_ptr->width)&7;
-               _asm
-               {
-                  movd       mm7, unmask       //load bit pattern
-                  psubb      mm6,mm6           //zero mm6
-                  punpcklbw  mm7,mm7
-                  punpcklwd  mm7,mm7
-                  punpckldq  mm7,mm7           //fill register with 8 masks
-
-                  movq       mm0,mask0
-                  movq       mm1,mask1
-
-                  pand       mm0,mm7
-                  pand       mm1,mm7
-
-                  pcmpeqb    mm0,mm6
-                  pcmpeqb    mm1,mm6
-
-                  mov        ecx,len           //load length of line
-                  mov        esi,srcptr        //load source
-                  mov        ebx,dstptr        //load dest
-                  cmp        ecx,0             //lcr
-                  jz         mainloop16end
-
-mainloop16:
-                  movq       mm4,[esi]
-                  pand       mm4,mm0
-                  movq       mm6,mm0
-                  movq       mm7,[ebx]
-                  pandn      mm6,mm7
-                  por        mm4,mm6
-                  movq       [ebx],mm4
-
-                  movq       mm5,[esi+8]
-                  pand       mm5,mm1
-                  movq       mm7,mm1
-                  movq       mm6,[ebx+8]
-                  pandn      mm7,mm6
-                  por        mm5,mm7
-                  movq       [ebx+8],mm5
-
-                  add        esi,16            //inc by 16 bytes processed
-                  add        ebx,16
-                  sub        ecx,8             //dec by 8 pixels processed
-
-                  ja         mainloop16
-
-mainloop16end:
-                  mov        ecx,diff
-                  cmp        ecx,0
-                  jz         end16
-
-                  mov        edx,mask
-                  sal        edx,24            //make low byte the high byte
-secondloop16:
-                  sal        edx,1             //move high bit to CF
-                  jnc        skip16            //if CF = 0
-                  mov        ax,[esi]
-                  mov        [ebx],ax
-skip16:
-                  add        esi,2
-                  add        ebx,2
-
-                  dec        ecx
-                  jnz        secondloop16
-end16:
-                  emms
-               }
-            }
-            else /* mmx not supported - use modified C routine */
-            {
-               register unsigned int incr1, initial_val, final_val;
-               png_size_t pixel_bytes;
-               png_uint_32 i;
-               register int disp = png_pass_inc[png_ptr->pass];
-               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
-
-               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
-               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
-                  pixel_bytes;
-               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
-               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
-               final_val = png_ptr->width*pixel_bytes;
-               incr1 = (disp)*pixel_bytes;
-               for (i = initial_val; i < final_val; i += incr1)
-               {
-                  png_memcpy(dstptr, srcptr, pixel_bytes);
-                  srcptr += incr1;
-                  dstptr += incr1;
-               }
-            } /* end of else */
-
-            break;
-         }       // end 16 bpp
-
-         case 24:
-         {
-            png_bytep srcptr;
-            png_bytep dstptr;
-            png_uint_32 len;
-            int unmask, diff;
-
-            __int64 mask2=0x0101010202020404,  //24bpp
-                    mask1=0x0408080810101020,
-                    mask0=0x2020404040808080;
-
-            srcptr = png_ptr->row_buf + 1;
-            dstptr = row;
-
-            unmask = ~mask;
-            len     = (png_ptr->width)&~7;
-            diff = (png_ptr->width)&7;
-
-            if (mmx_supported)
-            {
-               _asm
-               {
-                  movd       mm7, unmask       //load bit pattern
-                  psubb      mm6,mm6           //zero mm6
-                  punpcklbw  mm7,mm7
-                  punpcklwd  mm7,mm7
-                  punpckldq  mm7,mm7           //fill register with 8 masks
-
-                  movq       mm0,mask0
-                  movq       mm1,mask1
-                  movq       mm2,mask2
-
-                  pand       mm0,mm7
-                  pand       mm1,mm7
-                  pand       mm2,mm7
-
-                  pcmpeqb    mm0,mm6
-                  pcmpeqb    mm1,mm6
-                  pcmpeqb    mm2,mm6
-
-                  mov        ecx,len           //load length of line
-                  mov        esi,srcptr        //load source
-                  mov        ebx,dstptr        //load dest
-                  cmp        ecx,0
-                  jz         mainloop24end
-
-mainloop24:
-                  movq       mm4,[esi]
-                  pand       mm4,mm0
-                  movq       mm6,mm0
-                  movq       mm7,[ebx]
-                  pandn      mm6,mm7
-                  por        mm4,mm6
-                  movq       [ebx],mm4
-
-
-                  movq       mm5,[esi+8]
-                  pand       mm5,mm1
-                  movq       mm7,mm1
-                  movq       mm6,[ebx+8]
-                  pandn      mm7,mm6
-                  por        mm5,mm7
-                  movq       [ebx+8],mm5
-
-                  movq       mm6,[esi+16]
-                  pand       mm6,mm2
-                  movq       mm4,mm2
-                  movq       mm7,[ebx+16]
-                  pandn      mm4,mm7
-                  por        mm6,mm4
-                  movq       [ebx+16],mm6
-
-                  add        esi,24            //inc by 24 bytes processed
-                  add        ebx,24
-                  sub        ecx,8             //dec by 8 pixels processed
-
-                  ja         mainloop24
-
-mainloop24end:
-                  mov        ecx,diff
-                  cmp        ecx,0
-                  jz         end24
-
-                  mov        edx,mask
-                  sal        edx,24            //make low byte the high byte
-secondloop24:
-                  sal        edx,1             //move high bit to CF
-                  jnc        skip24            //if CF = 0
-                  mov        ax,[esi]
-                  mov        [ebx],ax
-                  xor        eax,eax
-                  mov        al,[esi+2]
-                  mov        [ebx+2],al
-skip24:
-                  add        esi,3
-                  add        ebx,3
-
-                  dec        ecx
-                  jnz        secondloop24
-
-end24:
-                  emms
-               }
-            }
-            else /* mmx not supported - use modified C routine */
-            {
-               register unsigned int incr1, initial_val, final_val;
-               png_size_t pixel_bytes;
-               png_uint_32 i;
-               register int disp = png_pass_inc[png_ptr->pass];
-               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
-
-               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
-               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
-                  pixel_bytes;
-               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
-               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
-               final_val = png_ptr->width*pixel_bytes;
-               incr1 = (disp)*pixel_bytes;
-               for (i = initial_val; i < final_val; i += incr1)
-               {
-                  png_memcpy(dstptr, srcptr, pixel_bytes);
-                  srcptr += incr1;
-                  dstptr += incr1;
-               }
-            } /* end of else */
-
-            break;
-         }       // end 24 bpp
-
-         case 32:
-         {
-            png_bytep srcptr;
-            png_bytep dstptr;
-            png_uint_32 len;
-            int unmask, diff;
-
-            __int64 mask3=0x0101010102020202,  //32bpp
-                    mask2=0x0404040408080808,
-                    mask1=0x1010101020202020,
-                    mask0=0x4040404080808080;
-
-            srcptr = png_ptr->row_buf + 1;
-            dstptr = row;
-
-            unmask = ~mask;
-            len     = (png_ptr->width)&~7;
-            diff = (png_ptr->width)&7;
-
-            if (mmx_supported)
-            {
-               _asm
-               {
-                  movd       mm7, unmask       //load bit pattern
-                  psubb      mm6,mm6           //zero mm6
-                  punpcklbw  mm7,mm7
-                  punpcklwd  mm7,mm7
-                  punpckldq  mm7,mm7           //fill register with 8 masks
-
-                  movq       mm0,mask0
-                  movq       mm1,mask1
-                  movq       mm2,mask2
-                  movq       mm3,mask3
-
-                  pand       mm0,mm7
-                  pand       mm1,mm7
-                  pand       mm2,mm7
-                  pand       mm3,mm7
-
-                  pcmpeqb    mm0,mm6
-                  pcmpeqb    mm1,mm6
-                  pcmpeqb    mm2,mm6
-                  pcmpeqb    mm3,mm6
-
-                  mov        ecx,len           //load length of line
-                  mov        esi,srcptr        //load source
-                  mov        ebx,dstptr        //load dest
-
-                  cmp        ecx,0             //lcr
-                  jz         mainloop32end
-
-mainloop32:
-                  movq       mm4,[esi]
-                  pand       mm4,mm0
-                  movq       mm6,mm0
-                  movq       mm7,[ebx]
-                  pandn      mm6,mm7
-                  por        mm4,mm6
-                  movq       [ebx],mm4
-
-                  movq       mm5,[esi+8]
-                  pand       mm5,mm1
-                  movq       mm7,mm1
-                  movq       mm6,[ebx+8]
-                  pandn      mm7,mm6
-                  por        mm5,mm7
-                  movq       [ebx+8],mm5
-
-                  movq       mm6,[esi+16]
-                  pand       mm6,mm2
-                  movq       mm4,mm2
-                  movq       mm7,[ebx+16]
-                  pandn      mm4,mm7
-                  por        mm6,mm4
-                  movq       [ebx+16],mm6
-
-                  movq       mm7,[esi+24]
-                  pand       mm7,mm3
-                  movq       mm5,mm3
-                  movq       mm4,[ebx+24]
-                  pandn      mm5,mm4
-                  por        mm7,mm5
-                  movq       [ebx+24],mm7
-
-                  add        esi,32            //inc by 32 bytes processed
-                  add        ebx,32
-                  sub        ecx,8             //dec by 8 pixels processed
-
-                  ja         mainloop32
-
-mainloop32end:
-                  mov        ecx,diff
-                  cmp        ecx,0
-                  jz         end32
-
-                  mov        edx,mask
-                  sal        edx,24            //make low byte the high byte
-secondloop32:
-                  sal        edx,1             //move high bit to CF
-                  jnc        skip32            //if CF = 0
-                  mov        eax,[esi]
-                  mov        [ebx],eax
-skip32:
-                  add        esi,4
-                  add        ebx,4
-
-                  dec        ecx
-                  jnz        secondloop32
-
-end32:
-                  emms
-               }
-            }
-            else /* mmx _not supported - Use modified C routine */
-            {
-               register unsigned int incr1, initial_val, final_val;
-               png_size_t pixel_bytes;
-               png_uint_32 i;
-               register int disp = png_pass_inc[png_ptr->pass];
-               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
-
-               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
-               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
-                  pixel_bytes;
-               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
-               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
-               final_val = png_ptr->width*pixel_bytes;
-               incr1 = (disp)*pixel_bytes;
-               for (i = initial_val; i < final_val; i += incr1)
-               {
-                  png_memcpy(dstptr, srcptr, pixel_bytes);
-                  srcptr += incr1;
-                  dstptr += incr1;
-               }
-            } /* end of else */
-
-            break;
-         }       // end 32 bpp
-
-         case 48:
-         {
-            png_bytep srcptr;
-            png_bytep dstptr;
-            png_uint_32 len;
-            int unmask, diff;
-
-            __int64 mask5=0x0101010101010202,
-                    mask4=0x0202020204040404,
-                    mask3=0x0404080808080808,
-                    mask2=0x1010101010102020,
-                    mask1=0x2020202040404040,
-                    mask0=0x4040808080808080;
-
-            if (mmx_supported)
-            {
-               srcptr = png_ptr->row_buf + 1;
-               dstptr = row;
-
-               unmask = ~mask;
-               len     = (png_ptr->width)&~7;
-               diff = (png_ptr->width)&7;
-               _asm
-               {
-                  movd       mm7, unmask       //load bit pattern
-                  psubb      mm6,mm6           //zero mm6
-                  punpcklbw  mm7,mm7
-                  punpcklwd  mm7,mm7
-                  punpckldq  mm7,mm7           //fill register with 8 masks
-
-                  movq       mm0,mask0
-                  movq       mm1,mask1
-                  movq       mm2,mask2
-                  movq       mm3,mask3
-                  movq       mm4,mask4
-                  movq       mm5,mask5
-
-                  pand       mm0,mm7
-                  pand       mm1,mm7
-                  pand       mm2,mm7
-                  pand       mm3,mm7
-                  pand       mm4,mm7
-                  pand       mm5,mm7
-
-                  pcmpeqb    mm0,mm6
-                  pcmpeqb    mm1,mm6
-                  pcmpeqb    mm2,mm6
-                  pcmpeqb    mm3,mm6
-                  pcmpeqb    mm4,mm6
-                  pcmpeqb    mm5,mm6
-
-                  mov        ecx,len           //load length of line
-                  mov        esi,srcptr        //load source
-                  mov        ebx,dstptr        //load dest
-
-                  cmp        ecx,0
-                  jz         mainloop48end
-
-mainloop48:
-                  movq       mm7,[esi]
-                  pand       mm7,mm0
-                  movq       mm6,mm0
-                  pandn      mm6,[ebx]
-                  por        mm7,mm6
-                  movq       [ebx],mm7
-
-                  movq       mm6,[esi+8]
-                  pand       mm6,mm1
-                  movq       mm7,mm1
-                  pandn      mm7,[ebx+8]
-                  por        mm6,mm7
-                  movq       [ebx+8],mm6
-
-                  movq       mm6,[esi+16]
-                  pand       mm6,mm2
-                  movq       mm7,mm2
-                  pandn      mm7,[ebx+16]
-                  por        mm6,mm7
-                  movq       [ebx+16],mm6
-
-                  movq       mm7,[esi+24]
-                  pand       mm7,mm3
-                  movq       mm6,mm3
-                  pandn      mm6,[ebx+24]
-                  por        mm7,mm6
-                  movq       [ebx+24],mm7
-
-                  movq       mm6,[esi+32]
-                  pand       mm6,mm4
-                  movq       mm7,mm4
-                  pandn      mm7,[ebx+32]
-                  por        mm6,mm7
-                  movq       [ebx+32],mm6
-
-                  movq       mm7,[esi+40]
-                  pand       mm7,mm5
-                  movq       mm6,mm5
-                  pandn      mm6,[ebx+40]
-                  por        mm7,mm6
-                  movq       [ebx+40],mm7
-
-                  add        esi,48            //inc by 32 bytes processed
-                  add        ebx,48
-                  sub        ecx,8             //dec by 8 pixels processed
-
-                  ja         mainloop48
-mainloop48end:
-
-                  mov        ecx,diff
-                  cmp        ecx,0
-                  jz         end48
-
-                  mov        edx,mask
-                  sal        edx,24            //make low byte the high byte
-
-secondloop48:
-                  sal        edx,1             //move high bit to CF
-                  jnc        skip48            //if CF = 0
-                  mov        eax,[esi]
-                  mov        [ebx],eax
-skip48:
-                  add        esi,4
-                  add        ebx,4
-
-                  dec        ecx
-                  jnz        secondloop48
-
-end48:
-                  emms
-               }
-            }
-            else /* mmx _not supported - Use modified C routine */
-            {
-               register unsigned int incr1, initial_val, final_val;
-               png_size_t pixel_bytes;
-               png_uint_32 i;
-               register int disp = png_pass_inc[png_ptr->pass];
-               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
-
-               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
-               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
-                  pixel_bytes;
-               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
-               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
-               final_val = png_ptr->width*pixel_bytes;
-               incr1 = (disp)*pixel_bytes;
-               for (i = initial_val; i < final_val; i += incr1)
-               {
-                  png_memcpy(dstptr, srcptr, pixel_bytes);
-                  srcptr += incr1;
-                  dstptr += incr1;
-               }
-            } /* end of else */
-
-            break;
-         }       // end 48 bpp
-
-         default:
-         {
-            png_bytep sptr;
-            png_bytep dp;
-            png_size_t pixel_bytes;
-            int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
-            unsigned int i;
-            register int disp = png_pass_inc[png_ptr->pass];  // get the offset
-            register unsigned int incr1, initial_val, final_val;
-
-            pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
-            sptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
-               pixel_bytes;
-            dp = row + offset_table[png_ptr->pass]*pixel_bytes;
-            initial_val = offset_table[png_ptr->pass]*pixel_bytes;
-            final_val = png_ptr->width*pixel_bytes;
-            incr1 = (disp)*pixel_bytes;
-            for (i = initial_val; i < final_val; i += incr1)
-            {
-               png_memcpy(dp, sptr, pixel_bytes);
-               sptr += incr1;
-               dp += incr1;
-            }
-            break;
-         }
-      } /* end switch (png_ptr->row_info.pixel_depth) */
-   } /* end if (non-trivial mask) */
-
-#ifdef DISABLE_PNGVCRD_COMBINE
-   mmx_supported = save_mmx_supported;
-#endif
-
-} /* end png_combine_row() */
-
-
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
-
-void
-png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
-   png_uint_32 transformations)
-{
-#ifndef ENABLE_PNGVCRD_INTERLACE
-   int save_mmx_supported = mmx_supported;
-#endif
-
-   png_debug(1,"in png_do_read_interlace\n");
-
-#ifndef ENABLE_PNGVCRD_INTERLACE
-   /* passes 0 and 2 affect rpng2-win + stefan_full_rgba.png
-    * symptom: first pixel in every 4th or 8th row is wrong color
-    * pass < 6 affects pngtest + any interlaced png
-    * symptom: corruption of heap, crash in png_destroy_read
-    */
-   if(pass < 6)
-      mmx_supported = 0;
-#else
-   if (mmx_supported == 2)
-       mmx_supported = mmxsupport();
-#endif
-
-   if (row != NULL && row_info != NULL)
-   {
-      png_uint_32 final_width;
-
-      final_width = row_info->width * png_pass_inc[pass];
-
-      switch (row_info->pixel_depth)
-      {
-         case 1:
-         {
-            png_bytep sp, dp;
-            int sshift, dshift;
-            int s_start, s_end, s_inc;
-            png_byte v;
-            png_uint_32 i;
-            int j;
-
-            sp = row + (png_size_t)((row_info->width - 1) >> 3);
-            dp = row + (png_size_t)((final_width - 1) >> 3);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
-            if (transformations & PNG_PACKSWAP)
-            {
-               sshift = (int)((row_info->width + 7) & 7);
-               dshift = (int)((final_width + 7) & 7);
-               s_start = 7;
-               s_end = 0;
-               s_inc = -1;
-            }
-            else
-#endif
-            {
-               sshift = 7 - (int)((row_info->width + 7) & 7);
-               dshift = 7 - (int)((final_width + 7) & 7);
-               s_start = 0;
-               s_end = 7;
-               s_inc = 1;
-            }
-
-            for (i = row_info->width; i; i--)
-            {
-               v = (png_byte)((*sp >> sshift) & 0x1);
-               for (j = 0; j < png_pass_inc[pass]; j++)
-               {
-                  *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
-                  *dp |= (png_byte)(v << dshift);
-                  if (dshift == s_end)
-                  {
-                     dshift = s_start;
-                     dp--;
-                  }
-                  else
-                     dshift += s_inc;
-               }
-               if (sshift == s_end)
-               {
-                  sshift = s_start;
-                  sp--;
-               }
-               else
-                  sshift += s_inc;
-            }
-            break;
-         }
-
-         case 2:
-         {
-            png_bytep sp, dp;
-            int sshift, dshift;
-            int s_start, s_end, s_inc;
-            png_uint_32 i;
-
-            sp = row + (png_size_t)((row_info->width - 1) >> 2);
-            dp = row + (png_size_t)((final_width - 1) >> 2);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
-            if (transformations & PNG_PACKSWAP)
-            {
-               sshift = (png_size_t)(((row_info->width + 3) & 3) << 1);
-               dshift = (png_size_t)(((final_width + 3) & 3) << 1);
-               s_start = 6;
-               s_end = 0;
-               s_inc = -2;
-            }
-            else
-#endif
-            {
-               sshift = (png_size_t)((3 - ((row_info->width + 3) & 3)) << 1);
-               dshift = (png_size_t)((3 - ((final_width + 3) & 3)) << 1);
-               s_start = 0;
-               s_end = 6;
-               s_inc = 2;
-            }
-
-            for (i = row_info->width; i; i--)
-            {
-               png_byte v;
-               int j;
-
-               v = (png_byte)((*sp >> sshift) & 0x3);
-               for (j = 0; j < png_pass_inc[pass]; j++)
-               {
-                  *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
-                  *dp |= (png_byte)(v << dshift);
-                  if (dshift == s_end)
-                  {
-                     dshift = s_start;
-                     dp--;
-                  }
-                  else
-                     dshift += s_inc;
-               }
-               if (sshift == s_end)
-               {
-                  sshift = s_start;
-                  sp--;
-               }
-               else
-                  sshift += s_inc;
-            }
-            break;
-         }
-
-         case 4:
-         {
-            png_bytep sp, dp;
-            int sshift, dshift;
-            int s_start, s_end, s_inc;
-            png_uint_32 i;
-
-            sp = row + (png_size_t)((row_info->width - 1) >> 1);
-            dp = row + (png_size_t)((final_width - 1) >> 1);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
-            if (transformations & PNG_PACKSWAP)
-            {
-               sshift = (png_size_t)(((row_info->width + 1) & 1) << 2);
-               dshift = (png_size_t)(((final_width + 1) & 1) << 2);
-               s_start = 4;
-               s_end = 0;
-               s_inc = -4;
-            }
-            else
-#endif
-            {
-               sshift = (png_size_t)((1 - ((row_info->width + 1) & 1)) << 2);
-               dshift = (png_size_t)((1 - ((final_width + 1) & 1)) << 2);
-               s_start = 0;
-               s_end = 4;
-               s_inc = 4;
-            }
-
-            for (i = row_info->width; i; i--)
-            {
-               png_byte v;
-               int j;
-
-               v = (png_byte)((*sp >> sshift) & 0xf);
-               for (j = 0; j < png_pass_inc[pass]; j++)
-               {
-                  *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
-                  *dp |= (png_byte)(v << dshift);
-                  if (dshift == s_end)
-                  {
-                     dshift = s_start;
-                     dp--;
-                  }
-                  else
-                     dshift += s_inc;
-               }
-               if (sshift == s_end)
-               {
-                  sshift = s_start;
-                  sp--;
-               }
-               else
-                  sshift += s_inc;
-            }
-            break;
-         }
-
-         default:         // This is the place where the routine is modified
-         {
-            __int64 const4 = 0x0000000000FFFFFF;
-            __int64 const5 = 0x000000FFFFFF0000;
-            __int64 const6 = 0x00000000000000FF;
-            //int mmx_supported = 1;
-
-            png_bytep sptr, dp;
-            png_uint_32 i;
-            png_size_t pixel_bytes;
-
-            int width = row_info->width;
-
-            pixel_bytes = (row_info->pixel_depth >> 3);
-
-            sptr = row + (row_info->width - 1) * pixel_bytes;
-            dp = row + (final_width - 1) * pixel_bytes;
-            // New code by Nirav Chhatrapati - Intel Corporation
-
-            if (mmx_supported) // use MMX routine if machine supports it
-            {
-               if (pixel_bytes == 3)
-               {
-                  if ((pass == 0) || (pass == 1))
-                  {
-                     _asm
-                     {
-                        mov esi, sptr
-                        mov edi, dp
-                        mov ecx, width
-                        sub edi, 21   // (png_pass_inc[pass] - 1)*pixel_bytes
-loop_pass0:
-                        movd mm0, [esi]     ; X X X X X v2 v1 v0
-                        pand mm0, const4    ; 0 0 0 0 0 v2 v1 v0
-                        movq mm1, mm0       ; 0 0 0 0 0 v2 v1 v0
-                        psllq mm0, 16       ; 0 0 0 v2 v1 v0 0 0
-                        movq mm2, mm0       ; 0 0 0 v2 v1 v0 0 0
-                        psllq mm0, 24       ; v2 v1 v0 0 0 0 0 0
-                        psrlq mm1, 8        ; 0 0 0 0 0 0 v2 v1
-                        por mm0, mm2        ; v2 v1 v0 v2 v1 v0 0 0
-                        por mm0, mm1        ; v2 v1 v0 v2 v1 v0 v2 v1
-                        movq mm3, mm0       ; v2 v1 v0 v2 v1 v0 v2 v1
-                        psllq mm0, 16       ; v0 v2 v1 v0 v2 v1 0 0
-                        movq mm4, mm3       ; v2 v1 v0 v2 v1 v0 v2 v1
-                        punpckhdq mm3, mm0  ; v0 v2 v1 v0 v2 v1 v0 v2
-                        movq [edi+16] , mm4
-                        psrlq mm0, 32       ; 0 0 0 0 v0 v2 v1 v0
-                        movq [edi+8] , mm3
-                        punpckldq mm0, mm4  ; v1 v0 v2 v1 v0 v2 v1 v0
-                        sub esi, 3
-                        movq [edi], mm0
-                        sub edi, 24
-                        //sub esi, 3
-                        dec ecx
-                        jnz loop_pass0
-                        EMMS
-                     }
-                  }
-                  else if ((pass == 2) || (pass == 3))
-                  {
-                     _asm
-                     {
-                        mov esi, sptr
-                        mov edi, dp
-                        mov ecx, width
-                        sub edi, 9   // (png_pass_inc[pass] - 1)*pixel_bytes
-loop_pass2:
-                        movd mm0, [esi]     ; X X X X X v2 v1 v0
-                        pand mm0, const4    ; 0 0 0 0 0 v2 v1 v0
-                        movq mm1, mm0       ; 0 0 0 0 0 v2 v1 v0
-                        psllq mm0, 16       ; 0 0 0 v2 v1 v0 0 0
-                        movq mm2, mm0       ; 0 0 0 v2 v1 v0 0 0
-                        psllq mm0, 24       ; v2 v1 v0 0 0 0 0 0
-                        psrlq mm1, 8        ; 0 0 0 0 0 0 v2 v1
-                        por mm0, mm2        ; v2 v1 v0 v2 v1 v0 0 0
-                        por mm0, mm1        ; v2 v1 v0 v2 v1 v0 v2 v1
-                        movq [edi+4], mm0   ; move to memory
-                        psrlq mm0, 16       ; 0 0 v2 v1 v0 v2 v1 v0
-                        movd [edi], mm0     ; move to memory
-                        sub esi, 3
-                        sub edi, 12
-                        dec ecx
-                        jnz loop_pass2
-                        EMMS
-                     }
-                  }
-                  else /* if ((pass == 4) || (pass == 5)) */
-                  {
-                     int width_mmx = ((width >> 1) << 1) - 8;
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 3
-                           sub edi, 9
-loop_pass4:
-                           movq mm0, [esi]     ; X X v2 v1 v0 v5 v4 v3
-                           movq mm7, mm0       ; X X v2 v1 v0 v5 v4 v3
-                           movq mm6, mm0       ; X X v2 v1 v0 v5 v4 v3
-                           psllq mm0, 24       ; v1 v0 v5 v4 v3 0 0 0
-                           pand mm7, const4    ; 0 0 0 0 0 v5 v4 v3
-                           psrlq mm6, 24       ; 0 0 0 X X v2 v1 v0
-                           por mm0, mm7        ; v1 v0 v5 v4 v3 v5 v4 v3
-                           movq mm5, mm6       ; 0 0 0 X X v2 v1 v0
-                           psllq mm6, 8        ; 0 0 X X v2 v1 v0 0
-                           movq [edi], mm0     ; move quad to memory
-                           psrlq mm5, 16       ; 0 0 0 0 0 X X v2
-                           pand mm5, const6    ; 0 0 0 0 0 0 0 v2
-                           por mm6, mm5        ; 0 0 X X v2 v1 v0 v2
-                           movd [edi+8], mm6   ; move double to memory
-                           sub esi, 6
-                           sub edi, 12
-                           sub ecx, 2
-                           jnz loop_pass4
-                           EMMS
-                        }
-                     }
-
-                     sptr -= width_mmx*3;
-                     dp -= width_mmx*6;
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
-                        }
-                        sptr -= pixel_bytes;
-                     }
-                  }
-               } /* end of pixel_bytes == 3 */
-
-               else if (pixel_bytes == 1)
-               {
-                  if ((pass == 0) || (pass == 1))
-                  {
-                     int width_mmx = ((width >> 2) << 2);
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub edi, 31
-                           sub esi, 3
-loop1_pass0:
-                           movd mm0, [esi]     ; X X X X v0 v1 v2 v3
-                           movq mm1, mm0       ; X X X X v0 v1 v2 v3
-                           punpcklbw mm0, mm0  ; v0 v0 v1 v1 v2 v2 v3 v3
-                           movq mm2, mm0       ; v0 v0 v1 v1 v2 v2 v3 v3
-                           punpcklwd mm0, mm0  ; v2 v2 v2 v2 v3 v3 v3 v3
-                           movq mm3, mm0       ; v2 v2 v2 v2 v3 v3 v3 v3
-                           punpckldq mm0, mm0  ; v3 v3 v3 v3 v3 v3 v3 v3
-                           punpckhdq mm3, mm3  ; v2 v2 v2 v2 v2 v2 v2 v2
-                           movq [edi], mm0     ; move to memory v3
-                           punpckhwd mm2, mm2  ; v0 v0 v0 v0 v1 v1 v1 v1
-                           movq [edi+8], mm3   ; move to memory v2
-                           movq mm4, mm2       ; v0 v0 v0 v0 v1 v1 v1 v1
-                           punpckldq mm2, mm2  ; v1 v1 v1 v1 v1 v1 v1 v1
-                           punpckhdq mm4, mm4  ; v0 v0 v0 v0 v0 v0 v0 v0
-                           movq [edi+16], mm2  ; move to memory v1
-                           movq [edi+24], mm4  ; move to memory v0
-                           sub esi, 4
-                           sub edi, 32
-                           sub ecx, 4
-                           jnz loop1_pass0
-                           EMMS
-                        }
-                     }
-
-                     sptr -= width_mmx;
-                     dp -= width_mmx*8;
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
-                        }
-                        sptr -= pixel_bytes;
-                     }
-                  }
-                  else if ((pass == 2) || (pass == 3))
-                  {
-                     int width_mmx = ((width >> 2) << 2);
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub edi, 15
-                           sub esi, 3
-loop1_pass2:
-                           movd mm0, [esi]     ; X X X X v0 v1 v2 v3
-                           punpcklbw mm0, mm0  ; v0 v0 v1 v1 v2 v2 v3 v3
-                           movq mm1, mm0       ; v0 v0 v1 v1 v2 v2 v3 v3
-                           punpcklwd mm0, mm0  ; v2 v2 v2 v2 v3 v3 v3 v3
-                           punpckhwd mm1, mm1  ; v0 v0 v0 v0 v1 v1 v1 v1
-                           movq [edi], mm0     ; move to memory v2 and v3
-                           sub esi, 4
-                           movq [edi+8], mm1   ; move to memory v1     and v0
-                           sub edi, 16
-                           sub ecx, 4
-                           jnz loop1_pass2
-                           EMMS
-                        }
-                     }
-
-                     sptr -= width_mmx;
-                     dp -= width_mmx*4;
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
-                        }
-                        sptr -= pixel_bytes;
-                     }
-                  }
-                  else //if ((pass == 4) || (pass == 5))
-                  {
-                     int width_mmx = ((width >> 3) << 3);
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub edi, 15
-                           sub esi, 7
-loop1_pass4:
-                           movq mm0, [esi]     ; v0 v1 v2 v3 v4 v5 v6 v7
-                           movq mm1, mm0       ; v0 v1 v2 v3 v4 v5 v6 v7
-                           punpcklbw mm0, mm0  ; v4 v4 v5 v5 v6 v6 v7 v7
-                           //movq mm1, mm0     ; v0 v0 v1 v1 v2 v2 v3 v3
-                           punpckhbw mm1, mm1  ;v0 v0 v1 v1 v2 v2 v3 v3
-                           movq [edi+8], mm1   ; move to memory v0 v1 v2 and v3
-                           sub esi, 8
-                           movq [edi], mm0     ; move to memory v4 v5 v6 and v7
-                           //sub esi, 4
-                           sub edi, 16
-                           sub ecx, 8
-                           jnz loop1_pass4
-                           EMMS
-                        }
-                     }
-
-                     sptr -= width_mmx;
-                     dp -= width_mmx*2;
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
-                        }
-                        sptr -= pixel_bytes;
-                     }
-                  }
-               } /* end of pixel_bytes == 1 */
-
-               else if (pixel_bytes == 2)
-               {
-                  if ((pass == 0) || (pass == 1))
-                  {
-                     int width_mmx = ((width >> 1) << 1);
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 2
-                           sub edi, 30
-loop2_pass0:
-                           movd mm0, [esi]        ; X X X X v1 v0 v3 v2
-                           punpcklwd mm0, mm0     ; v1 v0 v1 v0 v3 v2 v3 v2
-                           movq mm1, mm0          ; v1 v0 v1 v0 v3 v2 v3 v2
-                           punpckldq mm0, mm0     ; v3 v2 v3 v2 v3 v2 v3 v2
-                           punpckhdq mm1, mm1     ; v1 v0 v1 v0 v1 v0 v1 v0
-                           movq [edi], mm0
-                           movq [edi + 8], mm0
-                           movq [edi + 16], mm1
-                           movq [edi + 24], mm1
-                           sub esi, 4
-                           sub edi, 32
-                           sub ecx, 2
-                           jnz loop2_pass0
-                           EMMS
-                        }
-                     }
-
-                     sptr -= (width_mmx*2 + 2);
-                     dp -= (width_mmx*16 + 2);
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
-                        }
-                        //sptr -= pixel_bytes;
-                     }
-                  }
-
-                  else if ((pass == 2) || (pass == 3))
-                  {
-                     int width_mmx = ((width >> 1) << 1) ;
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 2
-                           sub edi, 14
-loop2_pass2:
-                           movd mm0, [esi]        ; X X X X v1 v0 v3 v2
-                           punpcklwd mm0, mm0     ; v1 v0 v1 v0 v3 v2 v3 v2
-                           movq mm1, mm0          ; v1 v0 v1 v0 v3 v2 v3 v2
-                           punpckldq mm0, mm0     ; v3 v2 v3 v2 v3 v2 v3 v2
-                           punpckhdq mm1, mm1     ; v1 v0 v1 v0 v1 v0 v1 v0
-                           movq [edi], mm0
-                           sub esi, 4
-                           movq [edi + 8], mm1
-                           //sub esi, 4
-                           sub edi, 16
-                           sub ecx, 2
-                           jnz loop2_pass2
-                           EMMS
-                        }
-                     }
-
-                     sptr -= (width_mmx*2 + 2);
-                     dp -= (width_mmx*8 + 2);
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
-                        }
-                        //sptr -= pixel_bytes;
-                     }
-                  }
-
-                  else // pass == 4 or 5
-                  {
-                     int width_mmx = ((width >> 1) << 1) ;
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 2
-                           sub edi, 6
-loop2_pass4:
-                           movd mm0, [esi]        ; X X X X v1 v0 v3 v2
-                           punpcklwd mm0, mm0     ; v1 v0 v1 v0 v3 v2 v3 v2
-                           sub esi, 4
-                           movq [edi], mm0
-                           sub edi, 8
-                           sub ecx, 2
-                           jnz loop2_pass4
-                           EMMS
-                        }
-                     }
-
-                     sptr -= (width_mmx*2 + 2);
-                     dp -= (width_mmx*4 + 2);
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
-                        }
-                        //sptr -= pixel_bytes;
-                     }
-                  }
-               } /* end of pixel_bytes == 2 */
-
-               else if (pixel_bytes == 4)
-               {
-                  if ((pass == 0) || (pass == 1))
-                  {
-                     int width_mmx = ((width >> 1) << 1) ;
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 4
-                           sub edi, 60
-loop4_pass0:
-                           movq mm0, [esi]        ; v3 v2 v1 v0 v7 v6 v5 v4
-                           movq mm1, mm0          ; v3 v2 v1 v0 v7 v6 v5 v4
-                           punpckldq mm0, mm0     ; v7 v6 v5 v4 v7 v6 v5 v4
-                           punpckhdq mm1, mm1     ; v3 v2 v1 v0 v3 v2 v1 v0
-                           movq [edi], mm0
-                           movq [edi + 8], mm0
-                           movq [edi + 16], mm0
-                           movq [edi + 24], mm0
-                           movq [edi+32], mm1
-                           movq [edi + 40], mm1
-                           movq [edi+ 48], mm1
-                           sub esi, 8
-                           movq [edi + 56], mm1
-                           sub edi, 64
-                           sub ecx, 2
-                           jnz loop4_pass0
-                           EMMS
-                        }
-                     }
-
-                     sptr -= (width_mmx*4 + 4);
-                     dp -= (width_mmx*32 + 4);
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
-                        }
-                        //sptr -= pixel_bytes;
-                     }
-                  }
-
-                  else if ((pass == 2) || (pass == 3))
-                  {
-                     int width_mmx = ((width >> 1) << 1) ;
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 4
-                           sub edi, 28
-loop4_pass2:
-                           movq mm0, [esi]      ; v3 v2 v1 v0 v7 v6 v5 v4
-                           movq mm1, mm0        ; v3 v2 v1 v0 v7 v6 v5 v4
-                           punpckldq mm0, mm0   ; v7 v6 v5 v4 v7 v6 v5 v4
-                           punpckhdq mm1, mm1   ; v3 v2 v1 v0 v3 v2 v1 v0
-                           movq [edi], mm0
-                           movq [edi + 8], mm0
-                           movq [edi+16], mm1
-                           movq [edi + 24], mm1
-                           sub esi, 8
-                           sub edi, 32
-                           sub ecx, 2
-                           jnz loop4_pass2
-                           EMMS
-                        }
-                     }
-
-                     sptr -= (width_mmx*4 + 4);
-                     dp -= (width_mmx*16 + 4);
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
-                        }
-                        //sptr -= pixel_bytes;
-                     }
-                  }
-
-                  else // pass == 4 or 5
-                  {
-                     int width_mmx = ((width >> 1) << 1) ;
-                     width -= width_mmx;
-                     if (width_mmx)
-                     {
-                        _asm
-                        {
-                           mov esi, sptr
-                           mov edi, dp
-                           mov ecx, width_mmx
-                           sub esi, 4
-                           sub edi, 12
-loop4_pass4:
-                           movq mm0, [esi]      ; v3 v2 v1 v0 v7 v6 v5 v4
-                           movq mm1, mm0        ; v3 v2 v1 v0 v7 v6 v5 v4
-                           punpckldq mm0, mm0   ; v7 v6 v5 v4 v7 v6 v5 v4
-                           punpckhdq mm1, mm1   ; v3 v2 v1 v0 v3 v2 v1 v0
-                           movq [edi], mm0
-                           sub esi, 8
-                           movq [edi + 8], mm1
-                           sub edi, 16
-                           sub ecx, 2
-                           jnz loop4_pass4
-                           EMMS
-                        }
-                     }
-
-                     sptr -= (width_mmx*4 + 4);
-                     dp -= (width_mmx*8 + 4);
-                     for (i = width; i; i--)
-                     {
-                        png_byte v[8];
-                        int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
-                        for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
-                        }
-                        //sptr -= pixel_bytes;
-                     }
-                  }
-
-               } /* end of pixel_bytes == 4 */
-
-               else if (pixel_bytes == 6)
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               } /* end of pixel_bytes == 6 */
-
-               else
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr-= pixel_bytes;
-                  }
-               }
-            } /* end of mmx_supported */
-
-            else /* MMX not supported:  use modified C code - takes advantage
-                  * of inlining of memcpy for a constant */
-            {
-               if (pixel_bytes == 1)
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               }
-               else if (pixel_bytes == 3)
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               }
-               else if (pixel_bytes == 2)
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               }
-               else if (pixel_bytes == 4)
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               }
-               else if (pixel_bytes == 6)
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               }
-               else
-               {
-                  for (i = row_info->width; i; i--)
-                  {
-                     png_byte v[8];
-                     int j;
-                     png_memcpy(v, sptr, pixel_bytes);
-                     for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
-                  }
-               }
-
-            } /* end of MMX not supported */
-            break;
-         }
-      } /* end switch (row_info->pixel_depth) */
-
-      row_info->width = final_width;
-      row_info->rowbytes = ((final_width *
-         (png_uint_32)row_info->pixel_depth + 7) >> 3);
-   }
-
-#ifndef ENABLE_PNGVCRD_INTERLACE
-   mmx_supported = save_mmx_supported;
-#endif
-}
-
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
-
-
-// These variables are utilized in the functions below.  They are declared
-// globally here to ensure alignment on 8-byte boundaries.
-
-union uAll {
-   __int64 use;
-   double  align;
-} LBCarryMask = {0x0101010101010101},
-  HBClearMask = {0x7f7f7f7f7f7f7f7f},
-  ActiveMask, ActiveMask2, ActiveMaskEnd, ShiftBpp, ShiftRem;
-
-
-// Optimized code for PNG Average filter decoder
-void
-png_read_filter_row_mmx_avg(png_row_infop row_info, png_bytep row
-                            , png_bytep prev_row)
-{
-   int bpp;
-   png_uint_32 FullLength;
-   png_uint_32 MMXLength;
-   //png_uint_32 len;
-   int diff;
-
-   bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
-   FullLength  = row_info->rowbytes; // # of bytes to filter
-   _asm {
-         // Init address pointers and offset
-         mov edi, row          // edi ==> Avg(x)
-         xor ebx, ebx          // ebx ==> x
-         mov edx, edi
-         mov esi, prev_row           // esi ==> Prior(x)
-         sub edx, bpp          // edx ==> Raw(x-bpp)
-
-         xor eax, eax
-         // Compute the Raw value for the first bpp bytes
-         //    Raw(x) = Avg(x) + (Prior(x)/2)
-davgrlp:
-         mov al, [esi + ebx]   // Load al with Prior(x)
-         inc ebx
-         shr al, 1             // divide by 2
-         add al, [edi+ebx-1]   // Add Avg(x); -1 to offset inc ebx
-         cmp ebx, bpp
-         mov [edi+ebx-1], al    // Write back Raw(x);
-                            // mov does not affect flags; -1 to offset inc ebx
-         jb davgrlp
-         // get # of bytes to alignment
-         mov diff, edi         // take start of row
-         add diff, ebx         // add bpp
-         add diff, 0xf         // add 7 + 8 to incr past alignment boundary
-         and diff, 0xfffffff8  // mask to alignment boundary
-         sub diff, edi         // subtract from start ==> value ebx at alignment
-         jz davggo
-         // fix alignment
-         // Compute the Raw value for the bytes upto the alignment boundary
-         //    Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
-         xor ecx, ecx
-davglp1:
-         xor eax, eax
-         mov cl, [esi + ebx]        // load cl with Prior(x)
-         mov al, [edx + ebx]  // load al with Raw(x-bpp)
-         add ax, cx
-         inc ebx
-         shr ax, 1            // divide by 2
-         add al, [edi+ebx-1]  // Add Avg(x); -1 to offset inc ebx
-         cmp ebx, diff              // Check if at alignment boundary
-         mov [edi+ebx-1], al        // Write back Raw(x);
-                            // mov does not affect flags; -1 to offset inc ebx
-         jb davglp1               // Repeat until at alignment boundary
-davggo:
-         mov eax, FullLength
-         mov ecx, eax
-         sub eax, ebx          // subtract alignment fix
-         and eax, 0x00000007   // calc bytes over mult of 8
-         sub ecx, eax          // drop over bytes from original length
-         mov MMXLength, ecx
-   } // end _asm block
-   // Now do the math for the rest of the row
-   switch ( bpp )
-   {
-      case 3:
-      {
-         ActiveMask.use  = 0x0000000000ffffff;
-         ShiftBpp.use = 24;    // == 3 * 8
-         ShiftRem.use = 40;    // == 64 - 24
-         _asm {
-            // Re-init address pointers and offset
-            movq mm7, ActiveMask
-            mov ebx, diff      // ebx ==> x = offset to alignment boundary
-            movq mm5, LBCarryMask
-            mov edi, row       // edi ==> Avg(x)
-            movq mm4, HBClearMask
-            mov esi, prev_row        // esi ==> Prior(x)
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
-                               // (we correct position in loop below)
-davg3lp:
-            movq mm0, [edi + ebx]      // Load mm0 with Avg(x)
-            // Add (Prev_row/2) to Average
-            movq mm3, mm5
-            psrlq mm2, ShiftRem      // Correct position Raw(x-bpp) data
-            movq mm1, [esi + ebx]    // Load mm1 with Prior(x)
-            movq mm6, mm7
-            pand mm3, mm1      // get lsb for each prev_row byte
-            psrlq mm1, 1       // divide prev_row bytes by 2
-            pand  mm1, mm4     // clear invalid bit 7 of each byte
-            paddb mm0, mm1     // add (Prev_row/2) to Avg for each byte
-            // Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
-            movq mm1, mm3      // now use mm1 for getting LBCarrys
-            pand mm1, mm2      // get LBCarrys for each byte where both
-                               // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1       // divide raw bytes by 2
-            pand  mm2, mm4     // clear invalid bit 7 of each byte
-            paddb mm2, mm1     // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6      // Leave only Active Group 1 bytes to add to Avg
-            paddb mm0, mm2     // add (Raw/2) + LBCarrys to Avg for each Active
-                               //  byte
-            // Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
-            psllq mm6, ShiftBpp  // shift the mm6 mask to cover bytes 3-5
-            movq mm2, mm0        // mov updated Raws to mm2
-            psllq mm2, ShiftBpp  // shift data to position correctly
-            movq mm1, mm3        // now use mm1 for getting LBCarrys
-            pand mm1, mm2      // get LBCarrys for each byte where both
-                               // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1       // divide raw bytes by 2
-            pand  mm2, mm4     // clear invalid bit 7 of each byte
-            paddb mm2, mm1     // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6      // Leave only Active Group 2 bytes to add to Avg
-            paddb mm0, mm2     // add (Raw/2) + LBCarrys to Avg for each Active
-                               //  byte
-
-            // Add 3rd active group (Raw(x-bpp)/2) to Average with LBCarry
-            psllq mm6, ShiftBpp  // shift the mm6 mask to cover the last two
-                                 // bytes
-            movq mm2, mm0        // mov updated Raws to mm2
-            psllq mm2, ShiftBpp  // shift data to position correctly
-                              // Data only needs to be shifted once here to
-                              // get the correct x-bpp offset.
-            movq mm1, mm3     // now use mm1 for getting LBCarrys
-            pand mm1, mm2     // get LBCarrys for each byte where both
-                              // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1      // divide raw bytes by 2
-            pand  mm2, mm4    // clear invalid bit 7 of each byte
-            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6     // Leave only Active Group 2 bytes to add to Avg
-            add ebx, 8
-            paddb mm0, mm2    // add (Raw/2) + LBCarrys to Avg for each Active
-                              // byte
-
-            // Now ready to write back to memory
-            movq [edi + ebx - 8], mm0
-            // Move updated Raw(x) to use as Raw(x-bpp) for next loop
-            cmp ebx, MMXLength
-            movq mm2, mm0     // mov updated Raw(x) to mm2
-            jb davg3lp
-         } // end _asm block
-      }
-      break;
-
-      case 6:
-      case 4:
-      case 7:
-      case 5:
-      {
-         ActiveMask.use  = 0xffffffffffffffff;  // use shift below to clear
-                                                // appropriate inactive bytes
-         ShiftBpp.use = bpp << 3;
-         ShiftRem.use = 64 - ShiftBpp.use;
-         _asm {
-            movq mm4, HBClearMask
-            // Re-init address pointers and offset
-            mov ebx, diff       // ebx ==> x = offset to alignment boundary
-            // Load ActiveMask and clear all bytes except for 1st active group
-            movq mm7, ActiveMask
-            mov edi, row         // edi ==> Avg(x)
-            psrlq mm7, ShiftRem
-            mov esi, prev_row    // esi ==> Prior(x)
-            movq mm6, mm7
-            movq mm5, LBCarryMask
-            psllq mm6, ShiftBpp  // Create mask for 2nd active group
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
-                                 // (we correct position in loop below)
-davg4lp:
-            movq mm0, [edi + ebx]
-            psrlq mm2, ShiftRem  // shift data to position correctly
-            movq mm1, [esi + ebx]
-            // Add (Prev_row/2) to Average
-            movq mm3, mm5
-            pand mm3, mm1     // get lsb for each prev_row byte
-            psrlq mm1, 1      // divide prev_row bytes by 2
-            pand  mm1, mm4    // clear invalid bit 7 of each byte
-            paddb mm0, mm1    // add (Prev_row/2) to Avg for each byte
-            // Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
-            movq mm1, mm3     // now use mm1 for getting LBCarrys
-            pand mm1, mm2     // get LBCarrys for each byte where both
-                              // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1      // divide raw bytes by 2
-            pand  mm2, mm4    // clear invalid bit 7 of each byte
-            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm7     // Leave only Active Group 1 bytes to add to Avg
-            paddb mm0, mm2    // add (Raw/2) + LBCarrys to Avg for each Active
-                              // byte
-            // Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
-            movq mm2, mm0     // mov updated Raws to mm2
-            psllq mm2, ShiftBpp // shift data to position correctly
-            add ebx, 8
-            movq mm1, mm3     // now use mm1 for getting LBCarrys
-            pand mm1, mm2     // get LBCarrys for each byte where both
-                              // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1      // divide raw bytes by 2
-            pand  mm2, mm4    // clear invalid bit 7 of each byte
-            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6     // Leave only Active Group 2 bytes to add to Avg
-            paddb mm0, mm2    // add (Raw/2) + LBCarrys to Avg for each Active
-                              // byte
-            cmp ebx, MMXLength
-            // Now ready to write back to memory
-            movq [edi + ebx - 8], mm0
-            // Prep Raw(x-bpp) for next loop
-            movq mm2, mm0     // mov updated Raws to mm2
-            jb davg4lp
-         } // end _asm block
-      }
-      break;
-      case 2:
-      {
-         ActiveMask.use  = 0x000000000000ffff;
-         ShiftBpp.use = 24;   // == 3 * 8
-         ShiftRem.use = 40;   // == 64 - 24
-         _asm {
-            // Load ActiveMask
-            movq mm7, ActiveMask
-            // Re-init address pointers and offset
-            mov ebx, diff     // ebx ==> x = offset to alignment boundary
-            movq mm5, LBCarryMask
-            mov edi, row      // edi ==> Avg(x)
-            movq mm4, HBClearMask
-            mov esi, prev_row  // esi ==> Prior(x)
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
-                              // (we correct position in loop below)
-davg2lp:
-            movq mm0, [edi + ebx]
-            psllq mm2, ShiftRem  // shift data to position correctly
-            movq mm1, [esi + ebx]
-            // Add (Prev_row/2) to Average
-            movq mm3, mm5
-            pand mm3, mm1     // get lsb for each prev_row byte
-            psrlq mm1, 1      // divide prev_row bytes by 2
-            pand  mm1, mm4    // clear invalid bit 7 of each byte
-            movq mm6, mm7
-            paddb mm0, mm1    // add (Prev_row/2) to Avg for each byte
-            // Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
-            movq mm1, mm3     // now use mm1 for getting LBCarrys
-            pand mm1, mm2     // get LBCarrys for each byte where both
-                              // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1      // divide raw bytes by 2
-            pand  mm2, mm4    // clear invalid bit 7 of each byte
-            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6     // Leave only Active Group 1 bytes to add to Avg
-            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
-            // Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
-            psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 2 & 3
-            movq mm2, mm0       // mov updated Raws to mm2
-            psllq mm2, ShiftBpp // shift data to position correctly
-            movq mm1, mm3       // now use mm1 for getting LBCarrys
-            pand mm1, mm2       // get LBCarrys for each byte where both
-                                // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1        // divide raw bytes by 2
-            pand  mm2, mm4      // clear invalid bit 7 of each byte
-            paddb mm2, mm1      // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6       // Leave only Active Group 2 bytes to add to Avg
-            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
-
-            // Add rdd active group (Raw(x-bpp)/2) to Average with LBCarry
-            psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 4 & 5
-            movq mm2, mm0       // mov updated Raws to mm2
-            psllq mm2, ShiftBpp // shift data to position correctly
-                                // Data only needs to be shifted once here to
-                                // get the correct x-bpp offset.
-            movq mm1, mm3       // now use mm1 for getting LBCarrys
-            pand mm1, mm2       // get LBCarrys for each byte where both
-                                // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1        // divide raw bytes by 2
-            pand  mm2, mm4      // clear invalid bit 7 of each byte
-            paddb mm2, mm1      // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6       // Leave only Active Group 2 bytes to add to Avg
-            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
-
-            // Add 4th active group (Raw(x-bpp)/2) to Average with LBCarry
-            psllq mm6, ShiftBpp  // shift the mm6 mask to cover bytes 6 & 7
-            movq mm2, mm0        // mov updated Raws to mm2
-            psllq mm2, ShiftBpp  // shift data to position correctly
-                                 // Data only needs to be shifted once here to
-                                 // get the correct x-bpp offset.
-            add ebx, 8
-            movq mm1, mm3    // now use mm1 for getting LBCarrys
-            pand mm1, mm2    // get LBCarrys for each byte where both
-                             // lsb's were == 1 (Only valid for active group)
-            psrlq mm2, 1     // divide raw bytes by 2
-            pand  mm2, mm4   // clear invalid bit 7 of each byte
-            paddb mm2, mm1   // add LBCarrys to (Raw(x-bpp)/2) for each byte
-            pand mm2, mm6    // Leave only Active Group 2 bytes to add to Avg
-            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
-
-            cmp ebx, MMXLength
-            // Now ready to write back to memory
-            movq [edi + ebx - 8], mm0
-            // Prep Raw(x-bpp) for next loop
-            movq mm2, mm0    // mov updated Raws to mm2
-            jb davg2lp
-        } // end _asm block
-      }
-      break;
-
-      case 1:                 // bpp == 1
-      {
-         _asm {
-            // Re-init address pointers and offset
-            mov ebx, diff     // ebx ==> x = offset to alignment boundary
-            mov edi, row      // edi ==> Avg(x)
-            cmp ebx, FullLength  // Test if offset at end of array
-            jnb davg1end
-            // Do Paeth decode for remaining bytes
-            mov esi, prev_row    // esi ==> Prior(x)
-            mov edx, edi
-            xor ecx, ecx         // zero ecx before using cl & cx in loop below
-            sub edx, bpp         // edx ==> Raw(x-bpp)
-davg1lp:
-            // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
-            xor eax, eax
-            mov cl, [esi + ebx]  // load cl with Prior(x)
-            mov al, [edx + ebx]  // load al with Raw(x-bpp)
-            add ax, cx
-            inc ebx
-            shr ax, 1            // divide by 2
-            add al, [edi+ebx-1]  // Add Avg(x); -1 to offset inc ebx
-            cmp ebx, FullLength  // Check if at end of array
-            mov [edi+ebx-1], al  // Write back Raw(x);
-                         // mov does not affect flags; -1 to offset inc ebx
-            jb davg1lp
-davg1end:
-         } // end _asm block
-      }
-      return;
-
-      case 8:             // bpp == 8
-      {
-         _asm {
-            // Re-init address pointers and offset
-            mov ebx, diff           // ebx ==> x = offset to alignment boundary
-            movq mm5, LBCarryMask
-            mov edi, row            // edi ==> Avg(x)
-            movq mm4, HBClearMask
-            mov esi, prev_row       // esi ==> Prior(x)
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
-                                // (NO NEED to correct position in loop below)
-davg8lp:
-            movq mm0, [edi + ebx]
-            movq mm3, mm5
-            movq mm1, [esi + ebx]
-            add ebx, 8
-            pand mm3, mm1       // get lsb for each prev_row byte
-            psrlq mm1, 1        // divide prev_row bytes by 2
-            pand mm3, mm2       // get LBCarrys for each byte where both
-                                // lsb's were == 1
-            psrlq mm2, 1        // divide raw bytes by 2
-            pand  mm1, mm4      // clear invalid bit 7 of each byte
-            paddb mm0, mm3      // add LBCarrys to Avg for each byte
-            pand  mm2, mm4      // clear invalid bit 7 of each byte
-            paddb mm0, mm1      // add (Prev_row/2) to Avg for each byte
-            paddb mm0, mm2      // add (Raw/2) to Avg for each byte
-            cmp ebx, MMXLength
-            movq [edi + ebx - 8], mm0
-            movq mm2, mm0       // reuse as Raw(x-bpp)
-            jb davg8lp
-        } // end _asm block
-      }
-      break;
-      default:                  // bpp greater than 8
-      {
-        _asm {
-            movq mm5, LBCarryMask
-            // Re-init address pointers and offset
-            mov ebx, diff       // ebx ==> x = offset to alignment boundary
-            mov edi, row        // edi ==> Avg(x)
-            movq mm4, HBClearMask
-            mov edx, edi
-            mov esi, prev_row   // esi ==> Prior(x)
-            sub edx, bpp        // edx ==> Raw(x-bpp)
-davgAlp:
-            movq mm0, [edi + ebx]
-            movq mm3, mm5
-            movq mm1, [esi + ebx]
-            pand mm3, mm1       // get lsb for each prev_row byte
-            movq mm2, [edx + ebx]
-            psrlq mm1, 1        // divide prev_row bytes by 2
-            pand mm3, mm2       // get LBCarrys for each byte where both
-                                // lsb's were == 1
-            psrlq mm2, 1        // divide raw bytes by 2
-            pand  mm1, mm4      // clear invalid bit 7 of each byte
-            paddb mm0, mm3      // add LBCarrys to Avg for each byte
-            pand  mm2, mm4      // clear invalid bit 7 of each byte
-            paddb mm0, mm1      // add (Prev_row/2) to Avg for each byte
-            add ebx, 8
-            paddb mm0, mm2      // add (Raw/2) to Avg for each byte
-            cmp ebx, MMXLength
-            movq [edi + ebx - 8], mm0
-            jb davgAlp
-        } // end _asm block
-      }
-      break;
-   }                         // end switch ( bpp )
-
-   _asm {
-         // MMX acceleration complete now do clean-up
-         // Check if any remaining bytes left to decode
-         mov ebx, MMXLength    // ebx ==> x = offset bytes remaining after MMX
-         mov edi, row          // edi ==> Avg(x)
-         cmp ebx, FullLength   // Test if offset at end of array
-         jnb davgend
-         // Do Paeth decode for remaining bytes
-         mov esi, prev_row     // esi ==> Prior(x)
-         mov edx, edi
-         xor ecx, ecx          // zero ecx before using cl & cx in loop below
-         sub edx, bpp          // edx ==> Raw(x-bpp)
-davglp2:
-         // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
-         xor eax, eax
-         mov cl, [esi + ebx]   // load cl with Prior(x)
-         mov al, [edx + ebx]   // load al with Raw(x-bpp)
-         add ax, cx
-         inc ebx
-         shr ax, 1              // divide by 2
-         add al, [edi+ebx-1]    // Add Avg(x); -1 to offset inc ebx
-         cmp ebx, FullLength    // Check if at end of array
-         mov [edi+ebx-1], al    // Write back Raw(x);
-                          // mov does not affect flags; -1 to offset inc ebx
-         jb davglp2
-davgend:
-         emms             // End MMX instructions; prep for possible FP instrs.
-   } // end _asm block
-}
-
-// Optimized code for PNG Paeth filter decoder
-void
-png_read_filter_row_mmx_paeth(png_row_infop row_info, png_bytep row,
-                              png_bytep prev_row)
-{
-   png_uint_32 FullLength;
-   png_uint_32 MMXLength;
-   //png_uint_32 len;
-   int bpp;
-   int diff;
-   //int ptemp;
-   int patemp, pbtemp, pctemp;
-
-   bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
-   FullLength  = row_info->rowbytes; // # of bytes to filter
-   _asm
-   {
-         xor ebx, ebx        // ebx ==> x offset
-         mov edi, row
-         xor edx, edx        // edx ==> x-bpp offset
-         mov esi, prev_row
-         xor eax, eax
-
-         // Compute the Raw value for the first bpp bytes
-         // Note: the formula works out to be always
-         //   Paeth(x) = Raw(x) + Prior(x)      where x < bpp
-dpthrlp:
-         mov al, [edi + ebx]
-         add al, [esi + ebx]
-         inc ebx
-         cmp ebx, bpp
-         mov [edi + ebx - 1], al
-         jb dpthrlp
-         // get # of bytes to alignment
-         mov diff, edi         // take start of row
-         add diff, ebx         // add bpp
-         xor ecx, ecx
-         add diff, 0xf         // add 7 + 8 to incr past alignment boundary
-         and diff, 0xfffffff8  // mask to alignment boundary
-         sub diff, edi         // subtract from start ==> value ebx at alignment
-         jz dpthgo
-         // fix alignment
-dpthlp1:
-         xor eax, eax
-         // pav = p - a = (a + b - c) - a = b - c
-         mov al, [esi + ebx]   // load Prior(x) into al
-         mov cl, [esi + edx]   // load Prior(x-bpp) into cl
-         sub eax, ecx          // subtract Prior(x-bpp)
-         mov patemp, eax       // Save pav for later use
-         xor eax, eax
-         // pbv = p - b = (a + b - c) - b = a - c
-         mov al, [edi + edx]   // load Raw(x-bpp) into al
-         sub eax, ecx          // subtract Prior(x-bpp)
-         mov ecx, eax
-         // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-         add eax, patemp       // pcv = pav + pbv
-         // pc = abs(pcv)
-         test eax, 0x80000000
-         jz dpthpca
-         neg eax               // reverse sign of neg values
-dpthpca:
-         mov pctemp, eax       // save pc for later use
-         // pb = abs(pbv)
-         test ecx, 0x80000000
-         jz dpthpba
-         neg ecx               // reverse sign of neg values
-dpthpba:
-         mov pbtemp, ecx       // save pb for later use
-         // pa = abs(pav)
-         mov eax, patemp
-         test eax, 0x80000000
-         jz dpthpaa
-         neg eax               // reverse sign of neg values
-dpthpaa:
-         mov patemp, eax       // save pa for later use
-         // test if pa <= pb
-         cmp eax, ecx
-         jna dpthabb
-         // pa > pb; now test if pb <= pc
-         cmp ecx, pctemp
-         jna dpthbbc
-         // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
-         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-         jmp dpthpaeth
-dpthbbc:
-         // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
-         mov cl, [esi + ebx]   // load Prior(x) into cl
-         jmp dpthpaeth
-dpthabb:
-         // pa <= pb; now test if pa <= pc
-         cmp eax, pctemp
-         jna dpthabc
-         // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
-         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-         jmp dpthpaeth
-dpthabc:
-         // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
-         mov cl, [edi + edx]  // load Raw(x-bpp) into cl
-dpthpaeth:
-         inc ebx
-         inc edx
-         // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
-         add [edi + ebx - 1], cl
-         cmp ebx, diff
-         jb dpthlp1
-dpthgo:
-         mov ecx, FullLength
-         mov eax, ecx
-         sub eax, ebx          // subtract alignment fix
-         and eax, 0x00000007   // calc bytes over mult of 8
-         sub ecx, eax          // drop over bytes from original length
-         mov MMXLength, ecx
-   } // end _asm block
-   // Now do the math for the rest of the row
-   switch ( bpp )
-   {
-      case 3:
-      {
-         ActiveMask.use = 0x0000000000ffffff;
-         ActiveMaskEnd.use = 0xffff000000000000;
-         ShiftBpp.use = 24;    // == bpp(3) * 8
-         ShiftRem.use = 40;    // == 64 - 24
-         _asm
-         {
-            mov ebx, diff
-            mov edi, row
-            mov esi, prev_row
-            pxor mm0, mm0
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]
-dpth3lp:
-            psrlq mm1, ShiftRem     // shift last 3 bytes to 1st 3 bytes
-            movq mm2, [esi + ebx]   // load b=Prior(x)
-            punpcklbw mm1, mm0      // Unpack High bytes of a
-            movq mm3, [esi+ebx-8]   // Prep c=Prior(x-bpp) bytes
-            punpcklbw mm2, mm0      // Unpack High bytes of b
-            psrlq mm3, ShiftRem     // shift last 3 bytes to 1st 3 bytes
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            punpcklbw mm3, mm0      // Unpack High bytes of c
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4    // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4       // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5    // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5       // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6    // Create mask pcv bytes < 0
-            pand mm0, mm6       // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5    // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6       // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            paddw mm7, mm3
-            pxor mm0, mm0
-            packuswb mm7, mm1
-            movq mm3, [esi + ebx]   // load c=Prior(x-bpp)
-            pand mm7, ActiveMask
-            movq mm2, mm3           // load b=Prior(x) step 1
-            paddb mm7, [edi + ebx]  // add Paeth predictor with Raw(x)
-            punpcklbw mm3, mm0      // Unpack High bytes of c
-            movq [edi + ebx], mm7   // write back updated value
-            movq mm1, mm7           // Now mm1 will be used as Raw(x-bpp)
-            // Now do Paeth for 2nd set of bytes (3-5)
-            psrlq mm2, ShiftBpp     // load b=Prior(x) step 2
-            punpcklbw mm1, mm0      // Unpack High bytes of a
-            pxor mm7, mm7
-            punpcklbw mm2, mm0      // Unpack High bytes of b
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            psubw mm5, mm3
-            psubw mm4, mm3
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) =
-            //       pav + pbv = pbv + pav
-            movq mm6, mm5
-            paddw mm6, mm4
-
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm5       // Create mask pbv bytes < 0
-            pcmpgtw mm7, mm4       // Create mask pav bytes < 0
-            pand mm0, mm5          // Only pbv bytes < 0 in mm0
-            pand mm7, mm4          // Only pav bytes < 0 in mm7
-            psubw mm5, mm0
-            psubw mm4, mm7
-            psubw mm5, mm0
-            psubw mm4, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
-            pand mm0, mm6          // Only pav bytes < 0 in mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5       // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6       // pab > pc?
-            movq mm2, [esi + ebx]  // load b=Prior(x)
-            pand mm3, mm7
-            pandn mm7, mm0
-            pxor mm1, mm1
-            paddw mm7, mm3
-            pxor mm0, mm0
-            packuswb mm7, mm1
-            movq mm3, mm2           // load c=Prior(x-bpp) step 1
-            pand mm7, ActiveMask
-            punpckhbw mm2, mm0      // Unpack High bytes of b
-            psllq mm7, ShiftBpp     // Shift bytes to 2nd group of 3 bytes
-             // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            paddb mm7, [edi + ebx]  // add Paeth predictor with Raw(x)
-            psllq mm3, ShiftBpp     // load c=Prior(x-bpp) step 2
-            movq [edi + ebx], mm7   // write back updated value
-            movq mm1, mm7
-            punpckhbw mm3, mm0      // Unpack High bytes of c
-            psllq mm1, ShiftBpp     // Shift bytes
-                                    // Now mm1 will be used as Raw(x-bpp)
-            // Now do Paeth for 3rd, and final, set of bytes (6-7)
-            pxor mm7, mm7
-            punpckhbw mm1, mm0      // Unpack High bytes of a
-            psubw mm4, mm3
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            pxor mm0, mm0
-            paddw mm6, mm5
-
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4    // Create mask pav bytes < 0
-            pcmpgtw mm7, mm5    // Create mask pbv bytes < 0
-            pand mm0, mm4       // Only pav bytes < 0 in mm7
-            pand mm7, mm5       // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6    // Create mask pcv bytes < 0
-            pand mm0, mm6       // Only pav bytes < 0 in mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5    // pa > pb?
-            movq mm0, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            pandn mm0, mm1
-            pandn mm7, mm4
-            paddw mm0, mm2
-            paddw mm7, mm5
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6    // pab > pc?
-            pand mm3, mm7
-            pandn mm7, mm0
-            paddw mm7, mm3
-            pxor mm1, mm1
-            packuswb mm1, mm7
-            // Step ebx to next set of 8 bytes and repeat loop til done
-            add ebx, 8
-            pand mm1, ActiveMaskEnd
-            paddb mm1, [edi + ebx - 8] // add Paeth predictor with Raw(x)
-
-            cmp ebx, MMXLength
-            pxor mm0, mm0              // pxor does not affect flags
-            movq [edi + ebx - 8], mm1  // write back updated value
-                                 // mm1 will be used as Raw(x-bpp) next loop
-                           // mm3 ready to be used as Prior(x-bpp) next loop
-            jb dpth3lp
-         } // end _asm block
-      }
-      break;
-
-      case 6:
-      case 7:
-      case 5:
-      {
-         ActiveMask.use  = 0x00000000ffffffff;
-         ActiveMask2.use = 0xffffffff00000000;
-         ShiftBpp.use = bpp << 3;    // == bpp * 8
-         ShiftRem.use = 64 - ShiftBpp.use;
-         _asm
-         {
-            mov ebx, diff
-            mov edi, row
-            mov esi, prev_row
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]
-            pxor mm0, mm0
-dpth6lp:
-            // Must shift to position Raw(x-bpp) data
-            psrlq mm1, ShiftRem
-            // Do first set of 4 bytes
-            movq mm3, [esi+ebx-8]      // read c=Prior(x-bpp) bytes
-            punpcklbw mm1, mm0      // Unpack Low bytes of a
-            movq mm2, [esi + ebx]   // load b=Prior(x)
-            punpcklbw mm2, mm0      // Unpack Low bytes of b
-            // Must shift to position Prior(x-bpp) data
-            psrlq mm3, ShiftRem
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            punpcklbw mm3, mm0      // Unpack Low bytes of c
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4    // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4       // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5    // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5       // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6    // Create mask pcv bytes < 0
-            pand mm0, mm6       // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5    // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6    // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            paddw mm7, mm3
-            pxor mm0, mm0
-            packuswb mm7, mm1
-            movq mm3, [esi + ebx - 8]  // load c=Prior(x-bpp)
-            pand mm7, ActiveMask
-            psrlq mm3, ShiftRem
-            movq mm2, [esi + ebx]      // load b=Prior(x) step 1
-            paddb mm7, [edi + ebx]     // add Paeth predictor with Raw(x)
-            movq mm6, mm2
-            movq [edi + ebx], mm7      // write back updated value
-            movq mm1, [edi+ebx-8]
-            psllq mm6, ShiftBpp
-            movq mm5, mm7
-            psrlq mm1, ShiftRem
-            por mm3, mm6
-            psllq mm5, ShiftBpp
-            punpckhbw mm3, mm0         // Unpack High bytes of c
-            por mm1, mm5
-            // Do second set of 4 bytes
-            punpckhbw mm2, mm0         // Unpack High bytes of b
-            punpckhbw mm1, mm0         // Unpack High bytes of a
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4          // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5          // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
-            pand mm0, mm6          // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5       // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6           // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            pxor mm1, mm1
-            paddw mm7, mm3
-            pxor mm0, mm0
-            // Step ex to next set of 8 bytes and repeat loop til done
-            add ebx, 8
-            packuswb mm1, mm7
-            paddb mm1, [edi + ebx - 8]     // add Paeth predictor with Raw(x)
-            cmp ebx, MMXLength
-            movq [edi + ebx - 8], mm1      // write back updated value
-                                // mm1 will be used as Raw(x-bpp) next loop
-            jb dpth6lp
-         } // end _asm block
-      }
-      break;
-
-      case 4:
-      {
-         ActiveMask.use  = 0x00000000ffffffff;
-         _asm {
-            mov ebx, diff
-            mov edi, row
-            mov esi, prev_row
-            pxor mm0, mm0
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]    // Only time should need to read
-                                     //  a=Raw(x-bpp) bytes
-dpth4lp:
-            // Do first set of 4 bytes
-            movq mm3, [esi+ebx-8]    // read c=Prior(x-bpp) bytes
-            punpckhbw mm1, mm0       // Unpack Low bytes of a
-            movq mm2, [esi + ebx]    // load b=Prior(x)
-            punpcklbw mm2, mm0       // Unpack High bytes of b
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            punpckhbw mm3, mm0       // Unpack High bytes of c
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4          // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5          // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
-            pand mm0, mm6          // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5       // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6       // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            paddw mm7, mm3
-            pxor mm0, mm0
-            packuswb mm7, mm1
-            movq mm3, [esi + ebx]      // load c=Prior(x-bpp)
-            pand mm7, ActiveMask
-            movq mm2, mm3              // load b=Prior(x) step 1
-            paddb mm7, [edi + ebx]     // add Paeth predictor with Raw(x)
-            punpcklbw mm3, mm0         // Unpack High bytes of c
-            movq [edi + ebx], mm7      // write back updated value
-            movq mm1, mm7              // Now mm1 will be used as Raw(x-bpp)
-            // Do second set of 4 bytes
-            punpckhbw mm2, mm0         // Unpack Low bytes of b
-            punpcklbw mm1, mm0         // Unpack Low bytes of a
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4          // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5          // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
-            pand mm0, mm6          // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5       // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6       // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            pxor mm1, mm1
-            paddw mm7, mm3
-            pxor mm0, mm0
-            // Step ex to next set of 8 bytes and repeat loop til done
-            add ebx, 8
-            packuswb mm1, mm7
-            paddb mm1, [edi + ebx - 8]     // add Paeth predictor with Raw(x)
-            cmp ebx, MMXLength
-            movq [edi + ebx - 8], mm1      // write back updated value
-                                // mm1 will be used as Raw(x-bpp) next loop
-            jb dpth4lp
-         } // end _asm block
-      }
-      break;
-      case 8:                          // bpp == 8
-      {
-         ActiveMask.use  = 0x00000000ffffffff;
-         _asm {
-            mov ebx, diff
-            mov edi, row
-            mov esi, prev_row
-            pxor mm0, mm0
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]      // Only time should need to read
-                                       //  a=Raw(x-bpp) bytes
-dpth8lp:
-            // Do first set of 4 bytes
-            movq mm3, [esi+ebx-8]      // read c=Prior(x-bpp) bytes
-            punpcklbw mm1, mm0         // Unpack Low bytes of a
-            movq mm2, [esi + ebx]      // load b=Prior(x)
-            punpcklbw mm2, mm0         // Unpack Low bytes of b
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            punpcklbw mm3, mm0         // Unpack Low bytes of c
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4          // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5          // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
-            pand mm0, mm6          // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5       // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6       // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            paddw mm7, mm3
-            pxor mm0, mm0
-            packuswb mm7, mm1
-            movq mm3, [esi+ebx-8]    // read c=Prior(x-bpp) bytes
-            pand mm7, ActiveMask
-            movq mm2, [esi + ebx]    // load b=Prior(x)
-            paddb mm7, [edi + ebx]   // add Paeth predictor with Raw(x)
-            punpckhbw mm3, mm0       // Unpack High bytes of c
-            movq [edi + ebx], mm7    // write back updated value
-            movq mm1, [edi+ebx-8]    // read a=Raw(x-bpp) bytes
-
-            // Do second set of 4 bytes
-            punpckhbw mm2, mm0       // Unpack High bytes of b
-            punpckhbw mm1, mm0       // Unpack High bytes of a
-            // pav = p - a = (a + b - c) - a = b - c
-            movq mm4, mm2
-            // pbv = p - b = (a + b - c) - b = a - c
-            movq mm5, mm1
-            psubw mm4, mm3
-            pxor mm7, mm7
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            movq mm6, mm4
-            psubw mm5, mm3
-            // pa = abs(p-a) = abs(pav)
-            // pb = abs(p-b) = abs(pbv)
-            // pc = abs(p-c) = abs(pcv)
-            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
-            paddw mm6, mm5
-            pand mm0, mm4          // Only pav bytes < 0 in mm7
-            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
-            psubw mm4, mm0
-            pand mm7, mm5          // Only pbv bytes < 0 in mm0
-            psubw mm4, mm0
-            psubw mm5, mm7
-            pxor mm0, mm0
-            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
-            pand mm0, mm6          // Only pav bytes < 0 in mm7
-            psubw mm5, mm7
-            psubw mm6, mm0
-            //  test pa <= pb
-            movq mm7, mm4
-            psubw mm6, mm0
-            pcmpgtw mm7, mm5       // pa > pb?
-            movq mm0, mm7
-            // use mm7 mask to merge pa & pb
-            pand mm5, mm7
-            // use mm0 mask copy to merge a & b
-            pand mm2, mm0
-            pandn mm7, mm4
-            pandn mm0, mm1
-            paddw mm7, mm5
-            paddw mm0, mm2
-            //  test  ((pa <= pb)? pa:pb) <= pc
-            pcmpgtw mm7, mm6       // pab > pc?
-            pxor mm1, mm1
-            pand mm3, mm7
-            pandn mm7, mm0
-            pxor mm1, mm1
-            paddw mm7, mm3
-            pxor mm0, mm0
-            // Step ex to next set of 8 bytes and repeat loop til done
-            add ebx, 8
-            packuswb mm1, mm7
-            paddb mm1, [edi + ebx - 8]     // add Paeth predictor with Raw(x)
-            cmp ebx, MMXLength
-            movq [edi + ebx - 8], mm1      // write back updated value
-                            // mm1 will be used as Raw(x-bpp) next loop
-            jb dpth8lp
-         } // end _asm block
-      }
-      break;
-
-      case 1:                // bpp = 1
-      case 2:                // bpp = 2
-      default:               // bpp > 8
-      {
-         _asm {
-            mov ebx, diff
-            cmp ebx, FullLength
-            jnb dpthdend
-            mov edi, row
-            mov esi, prev_row
-            // Do Paeth decode for remaining bytes
-            mov edx, ebx
-            xor ecx, ecx        // zero ecx before using cl & cx in loop below
-            sub edx, bpp        // Set edx = ebx - bpp
-dpthdlp:
-            xor eax, eax
-            // pav = p - a = (a + b - c) - a = b - c
-            mov al, [esi + ebx]        // load Prior(x) into al
-            mov cl, [esi + edx]        // load Prior(x-bpp) into cl
-            sub eax, ecx                 // subtract Prior(x-bpp)
-            mov patemp, eax                 // Save pav for later use
-            xor eax, eax
-            // pbv = p - b = (a + b - c) - b = a - c
-            mov al, [edi + edx]        // load Raw(x-bpp) into al
-            sub eax, ecx                 // subtract Prior(x-bpp)
-            mov ecx, eax
-            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-            add eax, patemp                 // pcv = pav + pbv
-            // pc = abs(pcv)
-            test eax, 0x80000000
-            jz dpthdpca
-            neg eax                     // reverse sign of neg values
-dpthdpca:
-            mov pctemp, eax             // save pc for later use
-            // pb = abs(pbv)
-            test ecx, 0x80000000
-            jz dpthdpba
-            neg ecx                     // reverse sign of neg values
-dpthdpba:
-            mov pbtemp, ecx             // save pb for later use
-            // pa = abs(pav)
-            mov eax, patemp
-            test eax, 0x80000000
-            jz dpthdpaa
-            neg eax                     // reverse sign of neg values
-dpthdpaa:
-            mov patemp, eax             // save pa for later use
-            // test if pa <= pb
-            cmp eax, ecx
-            jna dpthdabb
-            // pa > pb; now test if pb <= pc
-            cmp ecx, pctemp
-            jna dpthdbbc
-            // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
-            mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-            jmp dpthdpaeth
-dpthdbbc:
-            // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
-            mov cl, [esi + ebx]        // load Prior(x) into cl
-            jmp dpthdpaeth
-dpthdabb:
-            // pa <= pb; now test if pa <= pc
-            cmp eax, pctemp
-            jna dpthdabc
-            // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
-            mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-            jmp dpthdpaeth
-dpthdabc:
-            // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
-            mov cl, [edi + edx]  // load Raw(x-bpp) into cl
-dpthdpaeth:
-            inc ebx
-            inc edx
-            // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
-            add [edi + ebx - 1], cl
-            cmp ebx, FullLength
-            jb dpthdlp
-dpthdend:
-         } // end _asm block
-      }
-      return;                   // No need to go further with this one
-   }                         // end switch ( bpp )
-   _asm
-   {
-         // MMX acceleration complete now do clean-up
-         // Check if any remaining bytes left to decode
-         mov ebx, MMXLength
-         cmp ebx, FullLength
-         jnb dpthend
-         mov edi, row
-         mov esi, prev_row
-         // Do Paeth decode for remaining bytes
-         mov edx, ebx
-         xor ecx, ecx         // zero ecx before using cl & cx in loop below
-         sub edx, bpp         // Set edx = ebx - bpp
-dpthlp2:
-         xor eax, eax
-         // pav = p - a = (a + b - c) - a = b - c
-         mov al, [esi + ebx]  // load Prior(x) into al
-         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-         sub eax, ecx         // subtract Prior(x-bpp)
-         mov patemp, eax      // Save pav for later use
-         xor eax, eax
-         // pbv = p - b = (a + b - c) - b = a - c
-         mov al, [edi + edx]  // load Raw(x-bpp) into al
-         sub eax, ecx         // subtract Prior(x-bpp)
-         mov ecx, eax
-         // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
-         add eax, patemp      // pcv = pav + pbv
-         // pc = abs(pcv)
-         test eax, 0x80000000
-         jz dpthpca2
-         neg eax              // reverse sign of neg values
-dpthpca2:
-         mov pctemp, eax      // save pc for later use
-         // pb = abs(pbv)
-         test ecx, 0x80000000
-         jz dpthpba2
-         neg ecx              // reverse sign of neg values
-dpthpba2:
-         mov pbtemp, ecx      // save pb for later use
-         // pa = abs(pav)
-         mov eax, patemp
-         test eax, 0x80000000
-         jz dpthpaa2
-         neg eax              // reverse sign of neg values
-dpthpaa2:
-         mov patemp, eax      // save pa for later use
-         // test if pa <= pb
-         cmp eax, ecx
-         jna dpthabb2
-         // pa > pb; now test if pb <= pc
-         cmp ecx, pctemp
-         jna dpthbbc2
-         // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
-         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-         jmp dpthpaeth2
-dpthbbc2:
-         // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
-         mov cl, [esi + ebx]        // load Prior(x) into cl
-         jmp dpthpaeth2
-dpthabb2:
-         // pa <= pb; now test if pa <= pc
-         cmp eax, pctemp
-         jna dpthabc2
-         // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
-         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
-         jmp dpthpaeth2
-dpthabc2:
-         // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
-         mov cl, [edi + edx]  // load Raw(x-bpp) into cl
-dpthpaeth2:
-         inc ebx
-         inc edx
-         // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
-         add [edi + ebx - 1], cl
-         cmp ebx, FullLength
-         jb dpthlp2
-dpthend:
-         emms             // End MMX instructions; prep for possible FP instrs.
-   } // end _asm block
-}
-
-// Optimized code for PNG Sub filter decoder
-void
-png_read_filter_row_mmx_sub(png_row_infop row_info, png_bytep row)
-{
-   //int test;
-   int bpp;
-   png_uint_32 FullLength;
-   png_uint_32 MMXLength;
-   int diff;
-
-   bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
-   FullLength  = row_info->rowbytes - bpp; // # of bytes to filter
-   _asm {
-        mov edi, row
-        mov esi, edi               // lp = row
-        add edi, bpp               // rp = row + bpp
-        xor eax, eax
-        // get # of bytes to alignment
-        mov diff, edi               // take start of row
-        add diff, 0xf               // add 7 + 8 to incr past
-                                        // alignment boundary
-        xor ebx, ebx
-        and diff, 0xfffffff8        // mask to alignment boundary
-        sub diff, edi               // subtract from start ==> value
-                                        //  ebx at alignment
-        jz dsubgo
-        // fix alignment
-dsublp1:
-        mov al, [esi+ebx]
-        add [edi+ebx], al
-        inc ebx
-        cmp ebx, diff
-        jb dsublp1
-dsubgo:
-        mov ecx, FullLength
-        mov edx, ecx
-        sub edx, ebx                  // subtract alignment fix
-        and edx, 0x00000007           // calc bytes over mult of 8
-        sub ecx, edx                  // drop over bytes from length
-        mov MMXLength, ecx
-   } // end _asm block
-
-   // Now do the math for the rest of the row
-   switch ( bpp )
-   {
-        case 3:
-        {
-         ActiveMask.use  = 0x0000ffffff000000;
-         ShiftBpp.use = 24;       // == 3 * 8
-         ShiftRem.use  = 40;      // == 64 - 24
-         _asm {
-            mov edi, row
-            movq mm7, ActiveMask  // Load ActiveMask for 2nd active byte group
-            mov esi, edi              // lp = row
-            add edi, bpp          // rp = row + bpp
-            movq mm6, mm7
-            mov ebx, diff
-            psllq mm6, ShiftBpp   // Move mask in mm6 to cover 3rd active
-                                  // byte group
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]
-dsub3lp:
-            psrlq mm1, ShiftRem   // Shift data for adding 1st bpp bytes
-                          // no need for mask; shift clears inactive bytes
-            // Add 1st active group
-            movq mm0, [edi+ebx]
-            paddb mm0, mm1
-            // Add 2nd active group
-            movq mm1, mm0         // mov updated Raws to mm1
-            psllq mm1, ShiftBpp   // shift data to position correctly
-            pand mm1, mm7         // mask to use only 2nd active group
-            paddb mm0, mm1
-            // Add 3rd active group
-            movq mm1, mm0         // mov updated Raws to mm1
-            psllq mm1, ShiftBpp   // shift data to position correctly
-            pand mm1, mm6         // mask to use only 3rd active group
-            add ebx, 8
-            paddb mm0, mm1
-            cmp ebx, MMXLength
-            movq [edi+ebx-8], mm0     // Write updated Raws back to array
-            // Prep for doing 1st add at top of loop
-            movq mm1, mm0
-            jb dsub3lp
-         } // end _asm block
-      }
-      break;
-
-      case 1:
-      {
-         // Placed here just in case this is a duplicate of the
-         // non-MMX code for the SUB filter in png_read_filter_row above
-         //
-         //         png_bytep rp;
-         //         png_bytep lp;
-         //         png_uint_32 i;
-         //         bpp = (row_info->pixel_depth + 7) >> 3;
-         //         for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
-         //            i < row_info->rowbytes; i++, rp++, lp++)
-         //      {
-         //            *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
-         //      }
-         _asm {
-            mov ebx, diff
-            mov edi, row
-            cmp ebx, FullLength
-            jnb dsub1end
-            mov esi, edi          // lp = row
-            xor eax, eax
-            add edi, bpp      // rp = row + bpp
-dsub1lp:
-            mov al, [esi+ebx]
-            add [edi+ebx], al
-            inc ebx
-            cmp ebx, FullLength
-            jb dsub1lp
-dsub1end:
-         } // end _asm block
-      }
-      return;
-
-      case 6:
-      case 7:
-      case 4:
-      case 5:
-      {
-         ShiftBpp.use = bpp << 3;
-         ShiftRem.use = 64 - ShiftBpp.use;
-         _asm {
-            mov edi, row
-            mov ebx, diff
-            mov esi, edi               // lp = row
-            add edi, bpp           // rp = row + bpp
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]
-dsub4lp:
-            psrlq mm1, ShiftRem // Shift data for adding 1st bpp bytes
-                          // no need for mask; shift clears inactive bytes
-            movq mm0, [edi+ebx]
-            paddb mm0, mm1
-            // Add 2nd active group
-            movq mm1, mm0          // mov updated Raws to mm1
-            psllq mm1, ShiftBpp    // shift data to position correctly
-                                   // there is no need for any mask
-                                   // since shift clears inactive bits/bytes
-            add ebx, 8
-            paddb mm0, mm1
-            cmp ebx, MMXLength
-            movq [edi+ebx-8], mm0
-            movq mm1, mm0          // Prep for doing 1st add at top of loop
-            jb dsub4lp
-         } // end _asm block
-      }
-      break;
-
-      case 2:
-      {
-         ActiveMask.use  = 0x00000000ffff0000;
-         ShiftBpp.use = 16;       // == 2 * 8
-         ShiftRem.use = 48;       // == 64 - 16
-         _asm {
-            movq mm7, ActiveMask  // Load ActiveMask for 2nd active byte group
-            mov ebx, diff
-            movq mm6, mm7
-            mov edi, row
-            psllq mm6, ShiftBpp     // Move mask in mm6 to cover 3rd active
-                                    //  byte group
-            mov esi, edi            // lp = row
-            movq mm5, mm6
-            add edi, bpp            // rp = row + bpp
-            psllq mm5, ShiftBpp     // Move mask in mm5 to cover 4th active
-                                    //  byte group
-            // PRIME the pump (load the first Raw(x-bpp) data set
-            movq mm1, [edi+ebx-8]
-dsub2lp:
-            // Add 1st active group
-            psrlq mm1, ShiftRem     // Shift data for adding 1st bpp bytes
-                                    // no need for mask; shift clears inactive
-                                    //  bytes
-            movq mm0, [edi+ebx]
-            paddb mm0, mm1
-            // Add 2nd active group
-            movq mm1, mm0           // mov updated Raws to mm1
-            psllq mm1, ShiftBpp     // shift data to position correctly
-            pand mm1, mm7           // mask to use only 2nd active group
-            paddb mm0, mm1
-            // Add 3rd active group
-            movq mm1, mm0           // mov updated Raws to mm1
-            psllq mm1, ShiftBpp     // shift data to position correctly
-            pand mm1, mm6           // mask to use only 3rd active group
-            paddb mm0, mm1
-            // Add 4th active group
-            movq mm1, mm0           // mov updated Raws to mm1
-            psllq mm1, ShiftBpp     // shift data to position correctly
-            pand mm1, mm5           // mask to use only 4th active group
-            add ebx, 8
-            paddb mm0, mm1
-            cmp ebx, MMXLength
-            movq [edi+ebx-8], mm0   // Write updated Raws back to array
-            movq mm1, mm0           // Prep for doing 1st add at top of loop
-            jb dsub2lp
-         } // end _asm block
-      }
-      break;
-      case 8:
-      {
-         _asm {
-            mov edi, row
-            mov ebx, diff
-            mov esi, edi            // lp = row
-            add edi, bpp            // rp = row + bpp
-            mov ecx, MMXLength
-            movq mm7, [edi+ebx-8]   // PRIME the pump (load the first
-                                    // Raw(x-bpp) data set
-            and ecx, 0x0000003f     // calc bytes over mult of 64
-dsub8lp:
-            movq mm0, [edi+ebx]     // Load Sub(x) for 1st 8 bytes
-            paddb mm0, mm7
-            movq mm1, [edi+ebx+8]   // Load Sub(x) for 2nd 8 bytes
-            movq [edi+ebx], mm0    // Write Raw(x) for 1st 8 bytes
-                                   // Now mm0 will be used as Raw(x-bpp) for
-                                   // the 2nd group of 8 bytes.  This will be
-                                   // repeated for each group of 8 bytes with
-                                   // the 8th group being used as the Raw(x-bpp)
-                                   // for the 1st group of the next loop.
-            paddb mm1, mm0
-            movq mm2, [edi+ebx+16]  // Load Sub(x) for 3rd 8 bytes
-            movq [edi+ebx+8], mm1   // Write Raw(x) for 2nd 8 bytes
-            paddb mm2, mm1
-            movq mm3, [edi+ebx+24]  // Load Sub(x) for 4th 8 bytes
-            movq [edi+ebx+16], mm2  // Write Raw(x) for 3rd 8 bytes
-            paddb mm3, mm2
-            movq mm4, [edi+ebx+32]  // Load Sub(x) for 5th 8 bytes
-            movq [edi+ebx+24], mm3  // Write Raw(x) for 4th 8 bytes
-            paddb mm4, mm3
-            movq mm5, [edi+ebx+40]  // Load Sub(x) for 6th 8 bytes
-            movq [edi+ebx+32], mm4  // Write Raw(x) for 5th 8 bytes
-            paddb mm5, mm4
-            movq mm6, [edi+ebx+48]  // Load Sub(x) for 7th 8 bytes
-            movq [edi+ebx+40], mm5  // Write Raw(x) for 6th 8 bytes
-            paddb mm6, mm5
-            movq mm7, [edi+ebx+56]  // Load Sub(x) for 8th 8 bytes
-            movq [edi+ebx+48], mm6  // Write Raw(x) for 7th 8 bytes
-            add ebx, 64
-            paddb mm7, mm6
-            cmp ebx, ecx
-            movq [edi+ebx-8], mm7   // Write Raw(x) for 8th 8 bytes
-            jb dsub8lp
-            cmp ebx, MMXLength
-            jnb dsub8lt8
-dsub8lpA:
-            movq mm0, [edi+ebx]
-            add ebx, 8
-            paddb mm0, mm7
-            cmp ebx, MMXLength
-            movq [edi+ebx-8], mm0   // use -8 to offset early add to ebx
-            movq mm7, mm0           // Move calculated Raw(x) data to mm1 to
-                                    // be the new Raw(x-bpp) for the next loop
-            jb dsub8lpA
-dsub8lt8:
-         } // end _asm block
-      }
-      break;
-
-      default:                // bpp greater than 8 bytes
-      {
-         _asm {
-            mov ebx, diff
-            mov edi, row
-            mov esi, edi           // lp = row
-            add edi, bpp           // rp = row + bpp
-dsubAlp:
-            movq mm0, [edi+ebx]
-            movq mm1, [esi+ebx]
-            add ebx, 8
-            paddb mm0, mm1
-            cmp ebx, MMXLength
-            movq [edi+ebx-8], mm0  // mov does not affect flags; -8 to offset
-                                   //  add ebx
-            jb dsubAlp
-         } // end _asm block
-      }
-      break;
-
-   } // end switch ( bpp )
-
-   _asm {
-        mov ebx, MMXLength
-        mov edi, row
-        cmp ebx, FullLength
-        jnb dsubend
-        mov esi, edi               // lp = row
-        xor eax, eax
-        add edi, bpp               // rp = row + bpp
-dsublp2:
-        mov al, [esi+ebx]
-        add [edi+ebx], al
-        inc ebx
-        cmp ebx, FullLength
-        jb dsublp2
-dsubend:
-        emms             // End MMX instructions; prep for possible FP instrs.
-   } // end _asm block
-}
-
-// Optimized code for PNG Up filter decoder
-void
-png_read_filter_row_mmx_up(png_row_infop row_info, png_bytep row,
-   png_bytep prev_row)
-{
-   png_uint_32 len;
-   len  = row_info->rowbytes;       // # of bytes to filter
-   _asm {
-      mov edi, row
-      // get # of bytes to alignment
-      mov ecx, edi
-      xor ebx, ebx
-      add ecx, 0x7
-      xor eax, eax
-      and ecx, 0xfffffff8
-      mov esi, prev_row
-      sub ecx, edi
-      jz dupgo
-      // fix alignment
-duplp1:
-      mov al, [edi+ebx]
-      add al, [esi+ebx]
-      inc ebx
-      cmp ebx, ecx
-      mov [edi + ebx-1], al  // mov does not affect flags; -1 to offset inc ebx
-      jb duplp1
-dupgo:
-      mov ecx, len
-      mov edx, ecx
-      sub edx, ebx                  // subtract alignment fix
-      and edx, 0x0000003f           // calc bytes over mult of 64
-      sub ecx, edx                  // drop over bytes from length
-      // Unrolled loop - use all MMX registers and interleave to reduce
-      // number of branch instructions (loops) and reduce partial stalls
-duploop:
-      movq mm1, [esi+ebx]
-      movq mm0, [edi+ebx]
-      movq mm3, [esi+ebx+8]
-      paddb mm0, mm1
-      movq mm2, [edi+ebx+8]
-      movq [edi+ebx], mm0
-      paddb mm2, mm3
-      movq mm5, [esi+ebx+16]
-      movq [edi+ebx+8], mm2
-      movq mm4, [edi+ebx+16]
-      movq mm7, [esi+ebx+24]
-      paddb mm4, mm5
-      movq mm6, [edi+ebx+24]
-      movq [edi+ebx+16], mm4
-      paddb mm6, mm7
-      movq mm1, [esi+ebx+32]
-      movq [edi+ebx+24], mm6
-      movq mm0, [edi+ebx+32]
-      movq mm3, [esi+ebx+40]
-      paddb mm0, mm1
-      movq mm2, [edi+ebx+40]
-      movq [edi+ebx+32], mm0
-      paddb mm2, mm3
-      movq mm5, [esi+ebx+48]
-      movq [edi+ebx+40], mm2
-      movq mm4, [edi+ebx+48]
-      movq mm7, [esi+ebx+56]
-      paddb mm4, mm5
-      movq mm6, [edi+ebx+56]
-      movq [edi+ebx+48], mm4
-      add ebx, 64
-      paddb mm6, mm7
-      cmp ebx, ecx
-      movq [edi+ebx-8], mm6 // (+56)movq does not affect flags;
-                                     // -8 to offset add ebx
-      jb duploop
-
-      cmp edx, 0                     // Test for bytes over mult of 64
-      jz dupend
-
-
-      // 2 lines added by lcreeve@netins.net
-      // (mail 11 Jul 98 in png-implement list)
-      cmp edx, 8 //test for less than 8 bytes
-      jb duplt8
-
-
-      add ecx, edx
-      and edx, 0x00000007           // calc bytes over mult of 8
-      sub ecx, edx                  // drop over bytes from length
-      jz duplt8
-      // Loop using MMX registers mm0 & mm1 to update 8 bytes simultaneously
-duplpA:
-      movq mm1, [esi+ebx]
-      movq mm0, [edi+ebx]
-      add ebx, 8
-      paddb mm0, mm1
-      cmp ebx, ecx
-      movq [edi+ebx-8], mm0 // movq does not affect flags; -8 to offset add ebx
-      jb duplpA
-      cmp edx, 0            // Test for bytes over mult of 8
-      jz dupend
-duplt8:
-      xor eax, eax
-      add ecx, edx          // move over byte count into counter
-      // Loop using x86 registers to update remaining bytes
-duplp2:
-      mov al, [edi + ebx]
-      add al, [esi + ebx]
-      inc ebx
-      cmp ebx, ecx
-      mov [edi + ebx-1], al // mov does not affect flags; -1 to offset inc ebx
-      jb duplp2
-dupend:
-      // Conversion of filtered row completed
-      emms          // End MMX instructions; prep for possible FP instrs.
-   } // end _asm block
-}
-
-
-// Optimized png_read_filter_row routines
-void
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
-   row, png_bytep prev_row, int filter)
-{
-#ifdef PNG_DEBUG
-   char filnm[6];
-#endif
-   #define UseMMX (1)
-
-   if (mmx_supported == 2)
-       mmx_supported = mmxsupport();
-
-   if (!mmx_supported)
-   {
-       png_read_filter_row_c(png_ptr, row_info, row, prev_row, filter);
-       return ;
-   }
-
-#ifdef PNG_DEBUG
-   png_debug(1, "in png_read_filter_row\n");
-   png_debug1(0,"%s, ", (UseMMX?"MMX":"x86"));
-   switch (filter)
-   {
-      case 0: sprintf(filnm, "None ");
-         break;
-      case 1: sprintf(filnm, "Sub  ");
-         break;
-      case 2: sprintf(filnm, "Up   ");
-         break;
-      case 3: sprintf(filnm, "Avg  ");
-         break;
-      case 4: sprintf(filnm, "Paeth");
-         break;
-      default: sprintf(filnm, "Unknw");
-         break;
-   }
-   png_debug2(0,"row=%5d, %s, ", png_ptr->row_number, filnm);
-   png_debug2(0, "pd=%2d, b=%d, ", (int)row_info->pixel_depth,
-      (int)((row_info->pixel_depth + 7) >> 3));
-   png_debug1(0,"len=%8d, ", row_info->rowbytes);
-#endif
-
-   switch (filter)
-   {
-      case PNG_FILTER_VALUE_NONE:
-         break;
-      case PNG_FILTER_VALUE_SUB:
-      {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
-            (row_info->rowbytes >= 128) )
-         {
-            png_read_filter_row_mmx_sub(row_info, row);
-         }  //end if UseMMX
-         else
-         {
-            png_uint_32 i;
-            png_uint_32 istop = row_info->rowbytes;
-            png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
-            png_bytep rp = row + bpp;
-            png_bytep lp = row;
-
-            for (i = bpp; i < istop; i++)
-            {
-               *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
-               rp++;
-            }
-         }  //end !UseMMX
-         break;
-      }
-      case PNG_FILTER_VALUE_UP:
-      {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
-             (row_info->rowbytes >= 128) )
-         {
-            png_read_filter_row_mmx_up(row_info, row, prev_row);
-         }  //end if UseMMX
-         else
-         {
-            png_bytep rp;
-            png_bytep pp;
-            png_uint_32 i;
-            for (i = 0, rp = row, pp = prev_row;
-               i < row_info->rowbytes; i++, rp++, pp++)
-            {
-                  *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
-            }
-         }  //end !UseMMX
-         break;
-      }
-      case PNG_FILTER_VALUE_AVG:
-      {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
-             (row_info->rowbytes >= 128) )
-         {
-            png_read_filter_row_mmx_avg(row_info, row, prev_row);
-         }  //end if UseMMX
-         else
-         {
-            png_uint_32 i;
-            png_bytep rp = row;
-            png_bytep pp = prev_row;
-            png_bytep lp = row;
-            png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
-            png_uint_32 istop = row_info->rowbytes - bpp;
-
-            for (i = 0; i < bpp; i++)
-            {
-               *rp = (png_byte)(((int)(*rp) +
-                  ((int)(*pp++) >> 1)) & 0xff);
-               rp++;
-            }
-
-            for (i = 0; i < istop; i++)
-            {
-               *rp = (png_byte)(((int)(*rp) +
-                  ((int)(*pp++ + *lp++) >> 1)) & 0xff);
-               rp++;
-            }
-         }  //end !UseMMX
-         break;
-      }
-      case PNG_FILTER_VALUE_PAETH:
-      {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
-             (row_info->rowbytes >= 128) )
-         {
-            png_read_filter_row_mmx_paeth(row_info, row, prev_row);
-         }  //end if UseMMX
-         else
-         {
-            png_uint_32 i;
-            png_bytep rp = row;
-            png_bytep pp = prev_row;
-            png_bytep lp = row;
-            png_bytep cp = prev_row;
-            png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
-            png_uint_32 istop=row_info->rowbytes - bpp;
-
-            for (i = 0; i < bpp; i++)
-            {
-               *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
-               rp++;
-            }
-
-            for (i = 0; i < istop; i++)   // use leftover rp,pp
-            {
-               int a, b, c, pa, pb, pc, p;
-
-               a = *lp++;
-               b = *pp++;
-               c = *cp++;
-
-               p = b - c;
-               pc = a - c;
-
-#ifdef PNG_USE_ABS
-               pa = abs(p);
-               pb = abs(pc);
-               pc = abs(p + pc);
-#else
-               pa = p < 0 ? -p : p;
-               pb = pc < 0 ? -pc : pc;
-               pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
-
-               /*
-                  if (pa <= pb && pa <= pc)
-                     p = a;
-                  else if (pb <= pc)
-                     p = b;
-                  else
-                     p = c;
-                */
-
-               p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
-
-               *rp = (png_byte)(((int)(*rp) + p) & 0xff);
-               rp++;
-            }
-         }  //end !UseMMX
-         break;
-      }
-      default:
-         png_error(png_ptr, "Bad adaptive filter type");
-         break;
-   }
-}
-#endif
+/* pngvcrd.c - mixed C/assembler version of utilities to read a PNG file
+ *
+ * For Intel x86 CPU and Microsoft Visual C++ compiler
+ *
+ * libpng 1.0.4d - October 6, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998, Intel Corporation
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ *
+ * Contributed by Nirav Chhatrapati, Intel Corporation, 1998
+ * Interface to libpng contributed by Gilles Vollant, 1999
+ *
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD)
+
+static int mmx_supported=2;
+
+void
+png_read_filter_row_c(png_structp png_ptr, png_row_infop row_info,
+   png_bytep row, png_bytep prev_row, int filter);
+
+static int mmxsupport()
+{
+  int mmx_supported_local = 0;
+
+  _asm {
+    pushfd            //Save Eflag to stack
+    pop eax           //Get Eflag from stack into eax
+    mov ecx, eax      //Make another copy of Eflag in ecx
+    xor eax, 0x200000 //Toggle ID bit in Eflag [i.e. bit(21)]
+    push eax          //Save modified Eflag back to stack
+
+    popfd             //Restored modified value back to Eflag reg
+    pushfd            //Save Eflag to stack
+    pop eax           //Get Eflag from stack
+    xor eax, ecx      //Compare the new Eflag with the original Eflag
+    jz NOT_SUPPORTED  //If the same, CPUID instruction is not supported,
+                      //skip following instructions and jump to
+                      //NOT_SUPPORTED label
+
+    xor eax, eax      //Set eax to zero
+
+    _asm _emit 0x0f   //CPUID instruction  (two bytes opcode)
+    _asm _emit 0xa2
+
+    cmp eax, 1        //make sure eax return non-zero value
+    jl NOT_SUPPORTED  //If eax is zero, mmx not supported
+
+    xor eax, eax      //set eax to zero
+    inc eax           //Now increment eax to 1.  This instruction is
+                      //faster than the instruction "mov eax, 1"
+
+    _asm _emit 0x0f   //CPUID instruction
+    _asm _emit 0xa2
+
+    and edx, 0x00800000  //mask out all bits but mmx bit(24)
+    cmp edx, 0        // 0 = mmx not supported
+    jz  NOT_SUPPORTED // non-zero = Yes, mmx IS supported
+
+    mov  mmx_supported_local, 1  //set return value to 1
+
+NOT_SUPPORTED:
+    mov  eax, mmx_supported_local  //move return value to eax
+
+  }
+
+  //mmx_supported_local=0; // test code for force don't support MMX
+  //printf("MMX : %u (1=MMX supported)\n",mmx_supported_local);
+
+  return mmx_supported_local;
+}
+
+/* Combines the row recently read in with the previous row.
+   This routine takes care of alpha and transparency if requested.
+   This routine also handles the two methods of progressive display
+   of interlaced images, depending on the mask value.
+   The mask value describes which pixels are to be combined with
+   the row.  The pattern always repeats every 8 pixels, so just 8
+   bits are needed.  A one indicates the pixel is to be combined; a
+   zero indicates the pixel is to be skipped.  This is in addition
+   to any alpha or transparency value associated with the pixel.  If
+   you want all pixels to be combined, pass 0xff (255) in mask.  */
+
+/* Use this routine for x86 platform - uses faster MMX routine if machine
+   supports MMX */
+
+void
+png_combine_row(png_structp png_ptr, png_bytep row, int mask)
+{
+#ifdef DISABLE_PNGVCRD_COMBINE
+   int save_mmx_supported = mmx_supported;
+#endif
+
+   png_debug(1,"in png_combine_row_asm\n");
+
+#ifdef DISABLE_PNGVCRD_COMBINE
+   if ((png_ptr->transformations & PNG_INTERLACE) && png_ptr->pass != 6)
+       mmx_supported = 0;
+   else
+#endif
+       if (mmx_supported == 2)
+           mmx_supported = mmxsupport();
+
+   if (mask == 0xff)
+   {
+      png_memcpy(row, png_ptr->row_buf + 1,
+       (png_size_t)((png_ptr->width * png_ptr->row_info.pixel_depth + 7) >> 3));
+   }
+   /* GRR:  add "else if (mask == 0)" case?
+    *       or does png_combine_row() not even get called in that case? */
+   else
+   {
+      switch (png_ptr->row_info.pixel_depth)
+      {
+         case 1:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            int s_inc, s_start, s_end;
+            int m;
+            int shift;
+            png_uint_32 i;
+
+            sp = png_ptr->row_buf + 1;
+            dp = row;
+            m = 0x80;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+            if (png_ptr->transformations & PNG_PACKSWAP)
+            {
+                s_start = 0;
+                s_end = 7;
+                s_inc = 1;
+            }
+            else
+#endif
+            {
+                s_start = 7;
+                s_end = 0;
+                s_inc = -1;
+            }
+
+            shift = s_start;
+
+            for (i = 0; i < png_ptr->width; i++)
+            {
+               if (m & mask)
+               {
+                  int value;
+
+                  value = (*sp >> shift) & 0x1;
+                  *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+                  *dp |= (png_byte)(value << shift);
+               }
+
+               if (shift == s_end)
+               {
+                  shift = s_start;
+                  sp++;
+                  dp++;
+               }
+               else
+                  shift += s_inc;
+
+               if (m == 1)
+                  m = 0x80;
+               else
+                  m >>= 1;
+            }
+            break;
+         }
+
+         case 2:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            int s_start, s_end, s_inc;
+            int m;
+            int shift;
+            png_uint_32 i;
+            int value;
+
+            sp = png_ptr->row_buf + 1;
+            dp = row;
+            m = 0x80;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+            if (png_ptr->transformations & PNG_PACKSWAP)
+            {
+               s_start = 0;
+               s_end = 6;
+               s_inc = 2;
+            }
+            else
+#endif
+            {
+               s_start = 6;
+               s_end = 0;
+               s_inc = -2;
+            }
+
+            shift = s_start;
+
+            for (i = 0; i < png_ptr->width; i++)
+            {
+               if (m & mask)
+               {
+                  value = (*sp >> shift) & 0x3;
+                  *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                  *dp |= (png_byte)(value << shift);
+               }
+
+               if (shift == s_end)
+               {
+                  shift = s_start;
+                  sp++;
+                  dp++;
+               }
+               else
+                  shift += s_inc;
+               if (m == 1)
+                  m = 0x80;
+               else
+                  m >>= 1;
+            }
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            int s_start, s_end, s_inc;
+            int m;
+            int shift;
+            png_uint_32 i;
+            int value;
+
+            sp = png_ptr->row_buf + 1;
+            dp = row;
+            m = 0x80;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+            if (png_ptr->transformations & PNG_PACKSWAP)
+            {
+               s_start = 0;
+               s_end = 4;
+               s_inc = 4;
+            }
+            else
+#endif
+            {
+               s_start = 4;
+               s_end = 0;
+               s_inc = -4;
+            }
+            shift = s_start;
+
+            for (i = 0; i < png_ptr->width; i++)
+            {
+               if (m & mask)
+               {
+                  value = (*sp >> shift) & 0xf;
+                  *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                  *dp |= (png_byte)(value << shift);
+               }
+
+               if (shift == s_end)
+               {
+                  shift = s_start;
+                  sp++;
+                  dp++;
+               }
+               else
+                  shift += s_inc;
+               if (m == 1)
+                  m = 0x80;
+               else
+                  m >>= 1;
+            }
+            break;
+         }
+
+         case 8:
+         {
+            png_bytep srcptr;
+            png_bytep dstptr;
+            png_uint_32 len;
+            int m;
+            int diff, unmask;
+
+            __int64 mask0=0x0102040810204080;
+
+            if (mmx_supported)
+            {
+               srcptr = png_ptr->row_buf + 1;
+               dstptr = row;
+               m = 0x80;
+               unmask = ~mask;
+               len  = png_ptr->width &~7;  //reduce to multiple of 8
+               diff = png_ptr->width & 7;  //amount lost
+
+               _asm
+               {
+                  movd       mm7, unmask   //load bit pattern
+                  psubb      mm6,mm6       //zero mm6
+                  punpcklbw  mm7,mm7
+                  punpcklwd  mm7,mm7
+                  punpckldq  mm7,mm7       //fill register with 8 masks
+
+                  movq       mm0,mask0
+
+                  pand       mm0,mm7       //nonzero if keep byte
+                  pcmpeqb    mm0,mm6       //zeros->1s, v versa
+
+                  mov        ecx,len       //load length of line (pixels)
+                  mov        esi,srcptr    //load source
+                  mov        ebx,dstptr    //load dest
+                  cmp        ecx,0         //lcr
+                  je         mainloop8end
+
+mainloop8:
+                  movq       mm4,[esi]
+                  pand       mm4,mm0
+                  movq       mm6,mm0
+                  pandn      mm6,[ebx]
+                  por        mm4,mm6
+                  movq       [ebx],mm4
+
+                  add        esi,8         //inc by 8 bytes processed
+                  add        ebx,8
+                  sub        ecx,8         //dec by 8 pixels processed
+
+                  ja         mainloop8
+mainloop8end:
+
+                  mov        ecx,diff
+                  cmp        ecx,0
+                  jz         end8
+
+                  mov        edx,mask
+                  sal        edx,24        //make low byte the high byte
+
+secondloop8:
+                  sal        edx,1         //move high bit to CF
+                  jnc        skip8         //if CF = 0
+                  mov        al,[esi]
+                  mov        [ebx],al
+skip8:
+                  inc        esi
+                  inc        ebx
+
+                  dec        ecx
+                  jnz        secondloop8
+end8:
+                  emms
+               }
+            }
+            else /* mmx not supported - use modified C routine */
+            {
+               register unsigned int incr1, initial_val, final_val;
+               png_size_t pixel_bytes;
+               png_uint_32 i;
+               register int disp = png_pass_inc[png_ptr->pass];
+               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
+               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
+                  pixel_bytes;
+               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
+               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
+               final_val = png_ptr->width*pixel_bytes;
+               incr1 = (disp)*pixel_bytes;
+               for (i = initial_val; i < final_val; i += incr1)
+               {
+                  png_memcpy(dstptr, srcptr, pixel_bytes);
+                  srcptr += incr1;
+                  dstptr += incr1;
+               }
+            } /* end of else */
+
+            break;
+         }       // end 8 bpp
+
+         case 16:
+         {
+            png_bytep srcptr;
+            png_bytep dstptr;
+            png_uint_32 len;
+            int unmask, diff;
+            __int64 mask1=0x0101020204040808,
+                    mask0=0x1010202040408080;
+
+            if (mmx_supported)
+            {
+               srcptr = png_ptr->row_buf + 1;
+               dstptr = row;
+
+               unmask = ~mask;
+               len     = (png_ptr->width)&~7;
+               diff = (png_ptr->width)&7;
+               _asm
+               {
+                  movd       mm7, unmask       //load bit pattern
+                  psubb      mm6,mm6           //zero mm6
+                  punpcklbw  mm7,mm7
+                  punpcklwd  mm7,mm7
+                  punpckldq  mm7,mm7           //fill register with 8 masks
+
+                  movq       mm0,mask0
+                  movq       mm1,mask1
+
+                  pand       mm0,mm7
+                  pand       mm1,mm7
+
+                  pcmpeqb    mm0,mm6
+                  pcmpeqb    mm1,mm6
+
+                  mov        ecx,len           //load length of line
+                  mov        esi,srcptr        //load source
+                  mov        ebx,dstptr        //load dest
+                  cmp        ecx,0             //lcr
+                  jz         mainloop16end
+
+mainloop16:
+                  movq       mm4,[esi]
+                  pand       mm4,mm0
+                  movq       mm6,mm0
+                  movq       mm7,[ebx]
+                  pandn      mm6,mm7
+                  por        mm4,mm6
+                  movq       [ebx],mm4
+
+                  movq       mm5,[esi+8]
+                  pand       mm5,mm1
+                  movq       mm7,mm1
+                  movq       mm6,[ebx+8]
+                  pandn      mm7,mm6
+                  por        mm5,mm7
+                  movq       [ebx+8],mm5
+
+                  add        esi,16            //inc by 16 bytes processed
+                  add        ebx,16
+                  sub        ecx,8             //dec by 8 pixels processed
+
+                  ja         mainloop16
+
+mainloop16end:
+                  mov        ecx,diff
+                  cmp        ecx,0
+                  jz         end16
+
+                  mov        edx,mask
+                  sal        edx,24            //make low byte the high byte
+secondloop16:
+                  sal        edx,1             //move high bit to CF
+                  jnc        skip16            //if CF = 0
+                  mov        ax,[esi]
+                  mov        [ebx],ax
+skip16:
+                  add        esi,2
+                  add        ebx,2
+
+                  dec        ecx
+                  jnz        secondloop16
+end16:
+                  emms
+               }
+            }
+            else /* mmx not supported - use modified C routine */
+            {
+               register unsigned int incr1, initial_val, final_val;
+               png_size_t pixel_bytes;
+               png_uint_32 i;
+               register int disp = png_pass_inc[png_ptr->pass];
+               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
+               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
+                  pixel_bytes;
+               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
+               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
+               final_val = png_ptr->width*pixel_bytes;
+               incr1 = (disp)*pixel_bytes;
+               for (i = initial_val; i < final_val; i += incr1)
+               {
+                  png_memcpy(dstptr, srcptr, pixel_bytes);
+                  srcptr += incr1;
+                  dstptr += incr1;
+               }
+            } /* end of else */
+
+            break;
+         }       // end 16 bpp
+
+         case 24:
+         {
+            png_bytep srcptr;
+            png_bytep dstptr;
+            png_uint_32 len;
+            int unmask, diff;
+
+            __int64 mask2=0x0101010202020404,  //24bpp
+                    mask1=0x0408080810101020,
+                    mask0=0x2020404040808080;
+
+            srcptr = png_ptr->row_buf + 1;
+            dstptr = row;
+
+            unmask = ~mask;
+            len     = (png_ptr->width)&~7;
+            diff = (png_ptr->width)&7;
+
+            if (mmx_supported)
+            {
+               _asm
+               {
+                  movd       mm7, unmask       //load bit pattern
+                  psubb      mm6,mm6           //zero mm6
+                  punpcklbw  mm7,mm7
+                  punpcklwd  mm7,mm7
+                  punpckldq  mm7,mm7           //fill register with 8 masks
+
+                  movq       mm0,mask0
+                  movq       mm1,mask1
+                  movq       mm2,mask2
+
+                  pand       mm0,mm7
+                  pand       mm1,mm7
+                  pand       mm2,mm7
+
+                  pcmpeqb    mm0,mm6
+                  pcmpeqb    mm1,mm6
+                  pcmpeqb    mm2,mm6
+
+                  mov        ecx,len           //load length of line
+                  mov        esi,srcptr        //load source
+                  mov        ebx,dstptr        //load dest
+                  cmp        ecx,0
+                  jz         mainloop24end
+
+mainloop24:
+                  movq       mm4,[esi]
+                  pand       mm4,mm0
+                  movq       mm6,mm0
+                  movq       mm7,[ebx]
+                  pandn      mm6,mm7
+                  por        mm4,mm6
+                  movq       [ebx],mm4
+
+
+                  movq       mm5,[esi+8]
+                  pand       mm5,mm1
+                  movq       mm7,mm1
+                  movq       mm6,[ebx+8]
+                  pandn      mm7,mm6
+                  por        mm5,mm7
+                  movq       [ebx+8],mm5
+
+                  movq       mm6,[esi+16]
+                  pand       mm6,mm2
+                  movq       mm4,mm2
+                  movq       mm7,[ebx+16]
+                  pandn      mm4,mm7
+                  por        mm6,mm4
+                  movq       [ebx+16],mm6
+
+                  add        esi,24            //inc by 24 bytes processed
+                  add        ebx,24
+                  sub        ecx,8             //dec by 8 pixels processed
+
+                  ja         mainloop24
+
+mainloop24end:
+                  mov        ecx,diff
+                  cmp        ecx,0
+                  jz         end24
+
+                  mov        edx,mask
+                  sal        edx,24            //make low byte the high byte
+secondloop24:
+                  sal        edx,1             //move high bit to CF
+                  jnc        skip24            //if CF = 0
+                  mov        ax,[esi]
+                  mov        [ebx],ax
+                  xor        eax,eax
+                  mov        al,[esi+2]
+                  mov        [ebx+2],al
+skip24:
+                  add        esi,3
+                  add        ebx,3
+
+                  dec        ecx
+                  jnz        secondloop24
+
+end24:
+                  emms
+               }
+            }
+            else /* mmx not supported - use modified C routine */
+            {
+               register unsigned int incr1, initial_val, final_val;
+               png_size_t pixel_bytes;
+               png_uint_32 i;
+               register int disp = png_pass_inc[png_ptr->pass];
+               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
+               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
+                  pixel_bytes;
+               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
+               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
+               final_val = png_ptr->width*pixel_bytes;
+               incr1 = (disp)*pixel_bytes;
+               for (i = initial_val; i < final_val; i += incr1)
+               {
+                  png_memcpy(dstptr, srcptr, pixel_bytes);
+                  srcptr += incr1;
+                  dstptr += incr1;
+               }
+            } /* end of else */
+
+            break;
+         }       // end 24 bpp
+
+         case 32:
+         {
+            png_bytep srcptr;
+            png_bytep dstptr;
+            png_uint_32 len;
+            int unmask, diff;
+
+            __int64 mask3=0x0101010102020202,  //32bpp
+                    mask2=0x0404040408080808,
+                    mask1=0x1010101020202020,
+                    mask0=0x4040404080808080;
+
+            srcptr = png_ptr->row_buf + 1;
+            dstptr = row;
+
+            unmask = ~mask;
+            len     = (png_ptr->width)&~7;
+            diff = (png_ptr->width)&7;
+
+            if (mmx_supported)
+            {
+               _asm
+               {
+                  movd       mm7, unmask       //load bit pattern
+                  psubb      mm6,mm6           //zero mm6
+                  punpcklbw  mm7,mm7
+                  punpcklwd  mm7,mm7
+                  punpckldq  mm7,mm7           //fill register with 8 masks
+
+                  movq       mm0,mask0
+                  movq       mm1,mask1
+                  movq       mm2,mask2
+                  movq       mm3,mask3
+
+                  pand       mm0,mm7
+                  pand       mm1,mm7
+                  pand       mm2,mm7
+                  pand       mm3,mm7
+
+                  pcmpeqb    mm0,mm6
+                  pcmpeqb    mm1,mm6
+                  pcmpeqb    mm2,mm6
+                  pcmpeqb    mm3,mm6
+
+                  mov        ecx,len           //load length of line
+                  mov        esi,srcptr        //load source
+                  mov        ebx,dstptr        //load dest
+
+                  cmp        ecx,0             //lcr
+                  jz         mainloop32end
+
+mainloop32:
+                  movq       mm4,[esi]
+                  pand       mm4,mm0
+                  movq       mm6,mm0
+                  movq       mm7,[ebx]
+                  pandn      mm6,mm7
+                  por        mm4,mm6
+                  movq       [ebx],mm4
+
+                  movq       mm5,[esi+8]
+                  pand       mm5,mm1
+                  movq       mm7,mm1
+                  movq       mm6,[ebx+8]
+                  pandn      mm7,mm6
+                  por        mm5,mm7
+                  movq       [ebx+8],mm5
+
+                  movq       mm6,[esi+16]
+                  pand       mm6,mm2
+                  movq       mm4,mm2
+                  movq       mm7,[ebx+16]
+                  pandn      mm4,mm7
+                  por        mm6,mm4
+                  movq       [ebx+16],mm6
+
+                  movq       mm7,[esi+24]
+                  pand       mm7,mm3
+                  movq       mm5,mm3
+                  movq       mm4,[ebx+24]
+                  pandn      mm5,mm4
+                  por        mm7,mm5
+                  movq       [ebx+24],mm7
+
+                  add        esi,32            //inc by 32 bytes processed
+                  add        ebx,32
+                  sub        ecx,8             //dec by 8 pixels processed
+
+                  ja         mainloop32
+
+mainloop32end:
+                  mov        ecx,diff
+                  cmp        ecx,0
+                  jz         end32
+
+                  mov        edx,mask
+                  sal        edx,24            //make low byte the high byte
+secondloop32:
+                  sal        edx,1             //move high bit to CF
+                  jnc        skip32            //if CF = 0
+                  mov        eax,[esi]
+                  mov        [ebx],eax
+skip32:
+                  add        esi,4
+                  add        ebx,4
+
+                  dec        ecx
+                  jnz        secondloop32
+
+end32:
+                  emms
+               }
+            }
+            else /* mmx _not supported - Use modified C routine */
+            {
+               register unsigned int incr1, initial_val, final_val;
+               png_size_t pixel_bytes;
+               png_uint_32 i;
+               register int disp = png_pass_inc[png_ptr->pass];
+               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
+               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
+                  pixel_bytes;
+               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
+               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
+               final_val = png_ptr->width*pixel_bytes;
+               incr1 = (disp)*pixel_bytes;
+               for (i = initial_val; i < final_val; i += incr1)
+               {
+                  png_memcpy(dstptr, srcptr, pixel_bytes);
+                  srcptr += incr1;
+                  dstptr += incr1;
+               }
+            } /* end of else */
+
+            break;
+         }       // end 32 bpp
+
+         case 48:
+         {
+            png_bytep srcptr;
+            png_bytep dstptr;
+            png_uint_32 len;
+            int unmask, diff;
+
+            __int64 mask5=0x0101010101010202,
+                    mask4=0x0202020204040404,
+                    mask3=0x0404080808080808,
+                    mask2=0x1010101010102020,
+                    mask1=0x2020202040404040,
+                    mask0=0x4040808080808080;
+
+            if (mmx_supported)
+            {
+               srcptr = png_ptr->row_buf + 1;
+               dstptr = row;
+
+               unmask = ~mask;
+               len     = (png_ptr->width)&~7;
+               diff = (png_ptr->width)&7;
+               _asm
+               {
+                  movd       mm7, unmask       //load bit pattern
+                  psubb      mm6,mm6           //zero mm6
+                  punpcklbw  mm7,mm7
+                  punpcklwd  mm7,mm7
+                  punpckldq  mm7,mm7           //fill register with 8 masks
+
+                  movq       mm0,mask0
+                  movq       mm1,mask1
+                  movq       mm2,mask2
+                  movq       mm3,mask3
+                  movq       mm4,mask4
+                  movq       mm5,mask5
+
+                  pand       mm0,mm7
+                  pand       mm1,mm7
+                  pand       mm2,mm7
+                  pand       mm3,mm7
+                  pand       mm4,mm7
+                  pand       mm5,mm7
+
+                  pcmpeqb    mm0,mm6
+                  pcmpeqb    mm1,mm6
+                  pcmpeqb    mm2,mm6
+                  pcmpeqb    mm3,mm6
+                  pcmpeqb    mm4,mm6
+                  pcmpeqb    mm5,mm6
+
+                  mov        ecx,len           //load length of line
+                  mov        esi,srcptr        //load source
+                  mov        ebx,dstptr        //load dest
+
+                  cmp        ecx,0
+                  jz         mainloop48end
+
+mainloop48:
+                  movq       mm7,[esi]
+                  pand       mm7,mm0
+                  movq       mm6,mm0
+                  pandn      mm6,[ebx]
+                  por        mm7,mm6
+                  movq       [ebx],mm7
+
+                  movq       mm6,[esi+8]
+                  pand       mm6,mm1
+                  movq       mm7,mm1
+                  pandn      mm7,[ebx+8]
+                  por        mm6,mm7
+                  movq       [ebx+8],mm6
+
+                  movq       mm6,[esi+16]
+                  pand       mm6,mm2
+                  movq       mm7,mm2
+                  pandn      mm7,[ebx+16]
+                  por        mm6,mm7
+                  movq       [ebx+16],mm6
+
+                  movq       mm7,[esi+24]
+                  pand       mm7,mm3
+                  movq       mm6,mm3
+                  pandn      mm6,[ebx+24]
+                  por        mm7,mm6
+                  movq       [ebx+24],mm7
+
+                  movq       mm6,[esi+32]
+                  pand       mm6,mm4
+                  movq       mm7,mm4
+                  pandn      mm7,[ebx+32]
+                  por        mm6,mm7
+                  movq       [ebx+32],mm6
+
+                  movq       mm7,[esi+40]
+                  pand       mm7,mm5
+                  movq       mm6,mm5
+                  pandn      mm6,[ebx+40]
+                  por        mm7,mm6
+                  movq       [ebx+40],mm7
+
+                  add        esi,48            //inc by 32 bytes processed
+                  add        ebx,48
+                  sub        ecx,8             //dec by 8 pixels processed
+
+                  ja         mainloop48
+mainloop48end:
+
+                  mov        ecx,diff
+                  cmp        ecx,0
+                  jz         end48
+
+                  mov        edx,mask
+                  sal        edx,24            //make low byte the high byte
+
+secondloop48:
+                  sal        edx,1             //move high bit to CF
+                  jnc        skip48            //if CF = 0
+                  mov        eax,[esi]
+                  mov        [ebx],eax
+skip48:
+                  add        esi,4
+                  add        ebx,4
+
+                  dec        ecx
+                  jnz        secondloop48
+
+end48:
+                  emms
+               }
+            }
+            else /* mmx _not supported - Use modified C routine */
+            {
+               register unsigned int incr1, initial_val, final_val;
+               png_size_t pixel_bytes;
+               png_uint_32 i;
+               register int disp = png_pass_inc[png_ptr->pass];
+               int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
+               pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+               srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
+                  pixel_bytes;
+               dstptr = row + offset_table[png_ptr->pass]*pixel_bytes;
+               initial_val = offset_table[png_ptr->pass]*pixel_bytes;
+               final_val = png_ptr->width*pixel_bytes;
+               incr1 = (disp)*pixel_bytes;
+               for (i = initial_val; i < final_val; i += incr1)
+               {
+                  png_memcpy(dstptr, srcptr, pixel_bytes);
+                  srcptr += incr1;
+                  dstptr += incr1;
+               }
+            } /* end of else */
+
+            break;
+         }       // end 48 bpp
+
+         default:
+         {
+            png_bytep sptr;
+            png_bytep dp;
+            png_size_t pixel_bytes;
+            int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+            unsigned int i;
+            register int disp = png_pass_inc[png_ptr->pass];  // get the offset
+            register unsigned int incr1, initial_val, final_val;
+
+            pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+            sptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
+               pixel_bytes;
+            dp = row + offset_table[png_ptr->pass]*pixel_bytes;
+            initial_val = offset_table[png_ptr->pass]*pixel_bytes;
+            final_val = png_ptr->width*pixel_bytes;
+            incr1 = (disp)*pixel_bytes;
+            for (i = initial_val; i < final_val; i += incr1)
+            {
+               png_memcpy(dp, sptr, pixel_bytes);
+               sptr += incr1;
+               dp += incr1;
+            }
+            break;
+         }
+      } /* end switch (png_ptr->row_info.pixel_depth) */
+   } /* end if (non-trivial mask) */
+
+#ifdef DISABLE_PNGVCRD_COMBINE
+   mmx_supported = save_mmx_supported;
+#endif
+
+} /* end png_combine_row() */
+
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED)
+
+void
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+   png_uint_32 transformations)
+{
+#ifdef DISABLE_PNGVCRD_INTERLACE
+   int save_mmx_supported = mmx_supported;
+#endif
+
+   png_debug(1,"in png_do_read_interlace\n");
+
+#ifdef DISABLE_PNGVCRD_INTERLACE
+   /* A sign error in the post-MMX cleanup code for each pixel_depth resulted
+    * in bad pixels at the beginning of some rows of some images, and also
+    * (due to out-of-range memory reads and writes) caused heap corruption
+    * when compiled with MSVC 6.0.  The error is now fixed, and the code
+    * appears to work completely correctly, so it is enabled by default.
+    */
+   if (1)  /* all passes caused a heap problem in the old code */
+      mmx_supported = 0;
+   else
+#endif
+       if (mmx_supported == 2)
+           mmx_supported = mmxsupport();
+
+   if (row != NULL && row_info != NULL)
+   {
+      png_uint_32 final_width;
+
+      final_width = row_info->width * png_pass_inc[pass];
+
+      switch (row_info->pixel_depth)
+      {
+         case 1:
+         {
+            png_bytep sp, dp;
+            int sshift, dshift;
+            int s_start, s_end, s_inc;
+            png_byte v;
+            png_uint_32 i;
+            int j;
+
+            sp = row + (png_size_t)((row_info->width - 1) >> 3);
+            dp = row + (png_size_t)((final_width - 1) >> 3);
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+            if (transformations & PNG_PACKSWAP)
+            {
+               sshift = (int)((row_info->width + 7) & 7);
+               dshift = (int)((final_width + 7) & 7);
+               s_start = 7;
+               s_end = 0;
+               s_inc = -1;
+            }
+            else
+#endif
+            {
+               sshift = 7 - (int)((row_info->width + 7) & 7);
+               dshift = 7 - (int)((final_width + 7) & 7);
+               s_start = 0;
+               s_end = 7;
+               s_inc = 1;
+            }
+
+            for (i = row_info->width; i; i--)
+            {
+               v = (png_byte)((*sp >> sshift) & 0x1);
+               for (j = 0; j < png_pass_inc[pass]; j++)
+               {
+                  *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
+                  *dp |= (png_byte)(v << dshift);
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+                  else
+                     dshift += s_inc;
+               }
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+               else
+                  sshift += s_inc;
+            }
+            break;
+         }
+
+         case 2:
+         {
+            png_bytep sp, dp;
+            int sshift, dshift;
+            int s_start, s_end, s_inc;
+            png_uint_32 i;
+
+            sp = row + (png_size_t)((row_info->width - 1) >> 2);
+            dp = row + (png_size_t)((final_width - 1) >> 2);
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+            if (transformations & PNG_PACKSWAP)
+            {
+               sshift = (png_size_t)(((row_info->width + 3) & 3) << 1);
+               dshift = (png_size_t)(((final_width + 3) & 3) << 1);
+               s_start = 6;
+               s_end = 0;
+               s_inc = -2;
+            }
+            else
+#endif
+            {
+               sshift = (png_size_t)((3 - ((row_info->width + 3) & 3)) << 1);
+               dshift = (png_size_t)((3 - ((final_width + 3) & 3)) << 1);
+               s_start = 0;
+               s_end = 6;
+               s_inc = 2;
+            }
+
+            for (i = row_info->width; i; i--)
+            {
+               png_byte v;
+               int j;
+
+               v = (png_byte)((*sp >> sshift) & 0x3);
+               for (j = 0; j < png_pass_inc[pass]; j++)
+               {
+                  *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
+                  *dp |= (png_byte)(v << dshift);
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+                  else
+                     dshift += s_inc;
+               }
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+               else
+                  sshift += s_inc;
+            }
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp, dp;
+            int sshift, dshift;
+            int s_start, s_end, s_inc;
+            png_uint_32 i;
+
+            sp = row + (png_size_t)((row_info->width - 1) >> 1);
+            dp = row + (png_size_t)((final_width - 1) >> 1);
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+            if (transformations & PNG_PACKSWAP)
+            {
+               sshift = (png_size_t)(((row_info->width + 1) & 1) << 2);
+               dshift = (png_size_t)(((final_width + 1) & 1) << 2);
+               s_start = 4;
+               s_end = 0;
+               s_inc = -4;
+            }
+            else
+#endif
+            {
+               sshift = (png_size_t)((1 - ((row_info->width + 1) & 1)) << 2);
+               dshift = (png_size_t)((1 - ((final_width + 1) & 1)) << 2);
+               s_start = 0;
+               s_end = 4;
+               s_inc = 4;
+            }
+
+            for (i = row_info->width; i; i--)
+            {
+               png_byte v;
+               int j;
+
+               v = (png_byte)((*sp >> sshift) & 0xf);
+               for (j = 0; j < png_pass_inc[pass]; j++)
+               {
+                  *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
+                  *dp |= (png_byte)(v << dshift);
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+                  else
+                     dshift += s_inc;
+               }
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+               else
+                  sshift += s_inc;
+            }
+            break;
+         }
+
+         default:         // This is the place where the routine is modified
+         {
+            __int64 const4 = 0x0000000000FFFFFF;
+            __int64 const5 = 0x000000FFFFFF0000;
+            __int64 const6 = 0x00000000000000FF;
+            png_bytep sptr, dp;
+            png_uint_32 i;
+            png_size_t pixel_bytes;
+            int width = row_info->width;
+
+            pixel_bytes = (row_info->pixel_depth >> 3);
+
+            sptr = row + (width - 1) * pixel_bytes;
+            dp = row + (final_width - 1) * pixel_bytes;
+            // New code by Nirav Chhatrapati - Intel Corporation
+            // sign fix by GRR
+            // NOTE:  there is NO MMX code for 48-bit and 64-bit images
+
+            if (mmx_supported) // use MMX routine if machine supports it
+            {
+               if (pixel_bytes == 3)
+               {
+                  if ((pass == 0) || (pass == 1))
+                  {
+                     _asm
+                     {
+                        mov esi, sptr
+                        mov edi, dp
+                        mov ecx, width
+                        sub edi, 21   // (png_pass_inc[pass] - 1)*pixel_bytes
+loop_pass0:
+                        movd mm0, [esi]     ; X X X X X v2 v1 v0
+                        pand mm0, const4    ; 0 0 0 0 0 v2 v1 v0
+                        movq mm1, mm0       ; 0 0 0 0 0 v2 v1 v0
+                        psllq mm0, 16       ; 0 0 0 v2 v1 v0 0 0
+                        movq mm2, mm0       ; 0 0 0 v2 v1 v0 0 0
+                        psllq mm0, 24       ; v2 v1 v0 0 0 0 0 0
+                        psrlq mm1, 8        ; 0 0 0 0 0 0 v2 v1
+                        por mm0, mm2        ; v2 v1 v0 v2 v1 v0 0 0
+                        por mm0, mm1        ; v2 v1 v0 v2 v1 v0 v2 v1
+                        movq mm3, mm0       ; v2 v1 v0 v2 v1 v0 v2 v1
+                        psllq mm0, 16       ; v0 v2 v1 v0 v2 v1 0 0
+                        movq mm4, mm3       ; v2 v1 v0 v2 v1 v0 v2 v1
+                        punpckhdq mm3, mm0  ; v0 v2 v1 v0 v2 v1 v0 v2
+                        movq [edi+16] , mm4
+                        psrlq mm0, 32       ; 0 0 0 0 v0 v2 v1 v0
+                        movq [edi+8] , mm3
+                        punpckldq mm0, mm4  ; v1 v0 v2 v1 v0 v2 v1 v0
+                        sub esi, 3
+                        movq [edi], mm0
+                        sub edi, 24
+                        //sub esi, 3
+                        dec ecx
+                        jnz loop_pass0
+                        EMMS
+                     }
+                  }
+                  else if ((pass == 2) || (pass == 3))
+                  {
+                     _asm
+                     {
+                        mov esi, sptr
+                        mov edi, dp
+                        mov ecx, width
+                        sub edi, 9   // (png_pass_inc[pass] - 1)*pixel_bytes
+loop_pass2:
+                        movd mm0, [esi]     ; X X X X X v2 v1 v0
+                        pand mm0, const4    ; 0 0 0 0 0 v2 v1 v0
+                        movq mm1, mm0       ; 0 0 0 0 0 v2 v1 v0
+                        psllq mm0, 16       ; 0 0 0 v2 v1 v0 0 0
+                        movq mm2, mm0       ; 0 0 0 v2 v1 v0 0 0
+                        psllq mm0, 24       ; v2 v1 v0 0 0 0 0 0
+                        psrlq mm1, 8        ; 0 0 0 0 0 0 v2 v1
+                        por mm0, mm2        ; v2 v1 v0 v2 v1 v0 0 0
+                        por mm0, mm1        ; v2 v1 v0 v2 v1 v0 v2 v1
+                        movq [edi+4], mm0   ; move to memory
+                        psrlq mm0, 16       ; 0 0 v2 v1 v0 v2 v1 v0
+                        movd [edi], mm0     ; move to memory
+                        sub esi, 3
+                        sub edi, 12
+                        dec ecx
+                        jnz loop_pass2
+                        EMMS
+                     }
+                  }
+                  else /* if ((pass == 4) || (pass == 5)) */
+                  {
+                     int width_mmx = ((width >> 1) << 1) - 8;
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 3
+                           sub edi, 9
+loop_pass4:
+                           movq mm0, [esi]     ; X X v2 v1 v0 v5 v4 v3
+                           movq mm7, mm0       ; X X v2 v1 v0 v5 v4 v3
+                           movq mm6, mm0       ; X X v2 v1 v0 v5 v4 v3
+                           psllq mm0, 24       ; v1 v0 v5 v4 v3 0 0 0
+                           pand mm7, const4    ; 0 0 0 0 0 v5 v4 v3
+                           psrlq mm6, 24       ; 0 0 0 X X v2 v1 v0
+                           por mm0, mm7        ; v1 v0 v5 v4 v3 v5 v4 v3
+                           movq mm5, mm6       ; 0 0 0 X X v2 v1 v0
+                           psllq mm6, 8        ; 0 0 X X v2 v1 v0 0
+                           movq [edi], mm0     ; move quad to memory
+                           psrlq mm5, 16       ; 0 0 0 0 0 X X v2
+                           pand mm5, const6    ; 0 0 0 0 0 0 0 v2
+                           por mm6, mm5        ; 0 0 X X v2 v1 v0 v2
+                           movd [edi+8], mm6   ; move double to memory
+                           sub esi, 6
+                           sub edi, 12
+                           sub ecx, 2
+                           jnz loop_pass4
+                           EMMS
+                        }
+                     }
+
+                     sptr -= width_mmx*3;
+                     dp -= width_mmx*6;
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= pixel_bytes;
+                        }
+                        sptr -= pixel_bytes;
+                     }
+                  }
+               } /* end of pixel_bytes == 3 */
+
+               else if (pixel_bytes == 1)
+               {
+                  if ((pass == 0) || (pass == 1))
+                  {
+                     int width_mmx = ((width >> 2) << 2);
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub edi, 31
+                           sub esi, 3
+loop1_pass0:
+                           movd mm0, [esi]     ; X X X X v0 v1 v2 v3
+                           movq mm1, mm0       ; X X X X v0 v1 v2 v3
+                           punpcklbw mm0, mm0  ; v0 v0 v1 v1 v2 v2 v3 v3
+                           movq mm2, mm0       ; v0 v0 v1 v1 v2 v2 v3 v3
+                           punpcklwd mm0, mm0  ; v2 v2 v2 v2 v3 v3 v3 v3
+                           movq mm3, mm0       ; v2 v2 v2 v2 v3 v3 v3 v3
+                           punpckldq mm0, mm0  ; v3 v3 v3 v3 v3 v3 v3 v3
+                           punpckhdq mm3, mm3  ; v2 v2 v2 v2 v2 v2 v2 v2
+                           movq [edi], mm0     ; move to memory v3
+                           punpckhwd mm2, mm2  ; v0 v0 v0 v0 v1 v1 v1 v1
+                           movq [edi+8], mm3   ; move to memory v2
+                           movq mm4, mm2       ; v0 v0 v0 v0 v1 v1 v1 v1
+                           punpckldq mm2, mm2  ; v1 v1 v1 v1 v1 v1 v1 v1
+                           punpckhdq mm4, mm4  ; v0 v0 v0 v0 v0 v0 v0 v0
+                           movq [edi+16], mm2  ; move to memory v1
+                           movq [edi+24], mm4  ; move to memory v0
+                           sub esi, 4
+                           sub edi, 32
+                           sub ecx, 4
+                           jnz loop1_pass0
+                           EMMS
+                        }
+                     }
+
+                     sptr -= width_mmx;
+                     dp -= width_mmx*8;
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= pixel_bytes;
+                        }
+                        sptr -= pixel_bytes;
+                     }
+                  }
+                  else if ((pass == 2) || (pass == 3))
+                  {
+                     int width_mmx = ((width >> 2) << 2);
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub edi, 15
+                           sub esi, 3
+loop1_pass2:
+                           movd mm0, [esi]     ; X X X X v0 v1 v2 v3
+                           punpcklbw mm0, mm0  ; v0 v0 v1 v1 v2 v2 v3 v3
+                           movq mm1, mm0       ; v0 v0 v1 v1 v2 v2 v3 v3
+                           punpcklwd mm0, mm0  ; v2 v2 v2 v2 v3 v3 v3 v3
+                           punpckhwd mm1, mm1  ; v0 v0 v0 v0 v1 v1 v1 v1
+                           movq [edi], mm0     ; move to memory v2 and v3
+                           sub esi, 4
+                           movq [edi+8], mm1   ; move to memory v1     and v0
+                           sub edi, 16
+                           sub ecx, 4
+                           jnz loop1_pass2
+                           EMMS
+                        }
+                     }
+
+                     sptr -= width_mmx;
+                     dp -= width_mmx*4;
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= pixel_bytes;
+                        }
+                        sptr -= pixel_bytes;
+                     }
+                  }
+                  else //if ((pass == 4) || (pass == 5))
+                  {
+                     int width_mmx = ((width >> 3) << 3);
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub edi, 15
+                           sub esi, 7
+loop1_pass4:
+                           movq mm0, [esi]     ; v0 v1 v2 v3 v4 v5 v6 v7
+                           movq mm1, mm0       ; v0 v1 v2 v3 v4 v5 v6 v7
+                           punpcklbw mm0, mm0  ; v4 v4 v5 v5 v6 v6 v7 v7
+                           //movq mm1, mm0     ; v0 v0 v1 v1 v2 v2 v3 v3
+                           punpckhbw mm1, mm1  ;v0 v0 v1 v1 v2 v2 v3 v3
+                           movq [edi+8], mm1   ; move to memory v0 v1 v2 and v3
+                           sub esi, 8
+                           movq [edi], mm0     ; move to memory v4 v5 v6 and v7
+                           //sub esi, 4
+                           sub edi, 16
+                           sub ecx, 8
+                           jnz loop1_pass4
+                           EMMS
+                        }
+                     }
+
+                     sptr -= width_mmx;
+                     dp -= width_mmx*2;
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           png_memcpy(dp, v, pixel_bytes);
+                           dp -= pixel_bytes;
+                        }
+                        sptr -= pixel_bytes;
+                     }
+                  }
+               } /* end of pixel_bytes == 1 */
+
+               else if (pixel_bytes == 2)
+               {
+                  if ((pass == 0) || (pass == 1))
+                  {
+                     int width_mmx = ((width >> 1) << 1);
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 2
+                           sub edi, 30
+loop2_pass0:
+                           movd mm0, [esi]        ; X X X X v1 v0 v3 v2
+                           punpcklwd mm0, mm0     ; v1 v0 v1 v0 v3 v2 v3 v2
+                           movq mm1, mm0          ; v1 v0 v1 v0 v3 v2 v3 v2
+                           punpckldq mm0, mm0     ; v3 v2 v3 v2 v3 v2 v3 v2
+                           punpckhdq mm1, mm1     ; v1 v0 v1 v0 v1 v0 v1 v0
+                           movq [edi], mm0
+                           movq [edi + 8], mm0
+                           movq [edi + 16], mm1
+                           movq [edi + 24], mm1
+                           sub esi, 4
+                           sub edi, 32
+                           sub ecx, 2
+                           jnz loop2_pass0
+                           EMMS
+                        }
+                     }
+
+                     sptr -= (width_mmx*2 - 2);	// sign fixed
+                     dp -= (width_mmx*16 - 2);	// sign fixed
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+                        sptr -= pixel_bytes;
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, pixel_bytes);
+                        }
+                     }
+                  }
+
+                  else if ((pass == 2) || (pass == 3))
+                  {
+                     int width_mmx = ((width >> 1) << 1) ;
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 2
+                           sub edi, 14
+loop2_pass2:
+                           movd mm0, [esi]        ; X X X X v1 v0 v3 v2
+                           punpcklwd mm0, mm0     ; v1 v0 v1 v0 v3 v2 v3 v2
+                           movq mm1, mm0          ; v1 v0 v1 v0 v3 v2 v3 v2
+                           punpckldq mm0, mm0     ; v3 v2 v3 v2 v3 v2 v3 v2
+                           punpckhdq mm1, mm1     ; v1 v0 v1 v0 v1 v0 v1 v0
+                           movq [edi], mm0
+                           sub esi, 4
+                           movq [edi + 8], mm1
+                           //sub esi, 4
+                           sub edi, 16
+                           sub ecx, 2
+                           jnz loop2_pass2
+                           EMMS
+                        }
+                     }
+
+                     sptr -= (width_mmx*2 - 2);	// sign fixed
+                     dp -= (width_mmx*8 - 2);	// sign fixed
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+                        sptr -= pixel_bytes;
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, pixel_bytes);
+                        }
+                     }
+                  }
+
+                  else // pass == 4 or 5
+                  {
+                     int width_mmx = ((width >> 1) << 1) ;
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 2
+                           sub edi, 6
+loop2_pass4:
+                           movd mm0, [esi]        ; X X X X v1 v0 v3 v2
+                           punpcklwd mm0, mm0     ; v1 v0 v1 v0 v3 v2 v3 v2
+                           sub esi, 4
+                           movq [edi], mm0
+                           sub edi, 8
+                           sub ecx, 2
+                           jnz loop2_pass4
+                           EMMS
+                        }
+                     }
+
+                     sptr -= (width_mmx*2 - 2);	// sign fixed
+                     dp -= (width_mmx*4 - 2);	// sign fixed
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+                        sptr -= pixel_bytes;
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, pixel_bytes);
+                        }
+                     }
+                  }
+               } /* end of pixel_bytes == 2 */
+
+               else if (pixel_bytes == 4)
+               {
+                  if ((pass == 0) || (pass == 1))
+                  {
+                     int width_mmx = ((width >> 1) << 1) ;
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 4
+                           sub edi, 60
+loop4_pass0:
+                           movq mm0, [esi]        ; v3 v2 v1 v0 v7 v6 v5 v4
+                           movq mm1, mm0          ; v3 v2 v1 v0 v7 v6 v5 v4
+                           punpckldq mm0, mm0     ; v7 v6 v5 v4 v7 v6 v5 v4
+                           punpckhdq mm1, mm1     ; v3 v2 v1 v0 v3 v2 v1 v0
+                           movq [edi], mm0
+                           movq [edi + 8], mm0
+                           movq [edi + 16], mm0
+                           movq [edi + 24], mm0
+                           movq [edi+32], mm1
+                           movq [edi + 40], mm1
+                           movq [edi+ 48], mm1
+                           sub esi, 8
+                           movq [edi + 56], mm1
+                           sub edi, 64
+                           sub ecx, 2
+                           jnz loop4_pass0
+                           EMMS
+                        }
+                     }
+
+                     sptr -= (width_mmx*4 - 4);	// sign fixed
+                     dp -= (width_mmx*32 - 4);	// sign fixed
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+                        sptr -= pixel_bytes;
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, pixel_bytes);
+                        }
+                     }
+                  }
+
+                  else if ((pass == 2) || (pass == 3))
+                  {
+                     int width_mmx = ((width >> 1) << 1) ;
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 4
+                           sub edi, 28
+loop4_pass2:
+                           movq mm0, [esi]      ; v3 v2 v1 v0 v7 v6 v5 v4
+                           movq mm1, mm0        ; v3 v2 v1 v0 v7 v6 v5 v4
+                           punpckldq mm0, mm0   ; v7 v6 v5 v4 v7 v6 v5 v4
+                           punpckhdq mm1, mm1   ; v3 v2 v1 v0 v3 v2 v1 v0
+                           movq [edi], mm0
+                           movq [edi + 8], mm0
+                           movq [edi+16], mm1
+                           movq [edi + 24], mm1
+                           sub esi, 8
+                           sub edi, 32
+                           sub ecx, 2
+                           jnz loop4_pass2
+                           EMMS
+                        }
+                     }
+
+                     sptr -= (width_mmx*4 - 4);	// sign fixed
+                     dp -= (width_mmx*16 - 4);	// sign fixed
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+                        sptr -= pixel_bytes;
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, pixel_bytes);
+                        }
+                     }
+                  }
+
+                  else // pass == 4 or 5
+                  {
+                     int width_mmx = ((width >> 1) << 1) ;
+                     width -= width_mmx;
+                     if (width_mmx)
+                     {
+                        _asm
+                        {
+                           mov esi, sptr
+                           mov edi, dp
+                           mov ecx, width_mmx
+                           sub esi, 4
+                           sub edi, 12
+loop4_pass4:
+                           movq mm0, [esi]      ; v3 v2 v1 v0 v7 v6 v5 v4
+                           movq mm1, mm0        ; v3 v2 v1 v0 v7 v6 v5 v4
+                           punpckldq mm0, mm0   ; v7 v6 v5 v4 v7 v6 v5 v4
+                           punpckhdq mm1, mm1   ; v3 v2 v1 v0 v3 v2 v1 v0
+                           movq [edi], mm0
+                           sub esi, 8
+                           movq [edi + 8], mm1
+                           sub edi, 16
+                           sub ecx, 2
+                           jnz loop4_pass4
+                           EMMS
+                        }
+                     }
+
+                     sptr -= (width_mmx*4 - 4);	// sign fixed
+                     dp -= (width_mmx*8 - 4);	// sign fixed
+                     for (i = width; i; i--)
+                     {
+                        png_byte v[8];
+                        int j;
+                        sptr -= pixel_bytes;
+                        png_memcpy(v, sptr, pixel_bytes);
+                        for (j = 0; j < png_pass_inc[pass]; j++)
+                        {
+                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, pixel_bytes);
+                        }
+                     }
+                  }
+
+               } /* end of pixel_bytes == 4 */
+
+               else if (pixel_bytes == 6)
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               } /* end of pixel_bytes == 6 */
+
+               else
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr-= pixel_bytes;
+                  }
+               }
+            } /* end of mmx_supported */
+
+            else /* MMX not supported:  use modified C code - takes advantage
+                  * of inlining of memcpy for a constant */
+            {
+               if (pixel_bytes == 1)
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               }
+               else if (pixel_bytes == 3)
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               }
+               else if (pixel_bytes == 2)
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               }
+               else if (pixel_bytes == 4)
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               }
+               else if (pixel_bytes == 6)
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               }
+               else
+               {
+                  for (i = width; i; i--)
+                  {
+                     png_byte v[8];
+                     int j;
+                     png_memcpy(v, sptr, pixel_bytes);
+                     for (j = 0; j < png_pass_inc[pass]; j++)
+                     {
+                        png_memcpy(dp, v, pixel_bytes);
+                        dp -= pixel_bytes;
+                     }
+                     sptr -= pixel_bytes;
+                  }
+               }
+
+            } /* end of MMX not supported */
+            break;
+         }
+      } /* end switch (row_info->pixel_depth) */
+
+      row_info->width = final_width;
+      row_info->rowbytes = ((final_width *
+         (png_uint_32)row_info->pixel_depth + 7) >> 3);
+   }
+
+#ifdef DISABLE_PNGVCRD_INTERLACE
+   mmx_supported = save_mmx_supported;
+#endif
+}
+
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+
+// These variables are utilized in the functions below.  They are declared
+// globally here to ensure alignment on 8-byte boundaries.
+
+union uAll {
+   __int64 use;
+   double  align;
+} LBCarryMask = {0x0101010101010101},
+  HBClearMask = {0x7f7f7f7f7f7f7f7f},
+  ActiveMask, ActiveMask2, ActiveMaskEnd, ShiftBpp, ShiftRem;
+
+
+// Optimized code for PNG Average filter decoder
+void
+png_read_filter_row_mmx_avg(png_row_infop row_info, png_bytep row
+                            , png_bytep prev_row)
+{
+   int bpp;
+   png_uint_32 FullLength;
+   png_uint_32 MMXLength;
+   //png_uint_32 len;
+   int diff;
+
+   bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
+   FullLength  = row_info->rowbytes; // # of bytes to filter
+   _asm {
+         // Init address pointers and offset
+         mov edi, row          // edi ==> Avg(x)
+         xor ebx, ebx          // ebx ==> x
+         mov edx, edi
+         mov esi, prev_row           // esi ==> Prior(x)
+         sub edx, bpp          // edx ==> Raw(x-bpp)
+
+         xor eax, eax
+         // Compute the Raw value for the first bpp bytes
+         //    Raw(x) = Avg(x) + (Prior(x)/2)
+davgrlp:
+         mov al, [esi + ebx]   // Load al with Prior(x)
+         inc ebx
+         shr al, 1             // divide by 2
+         add al, [edi+ebx-1]   // Add Avg(x); -1 to offset inc ebx
+         cmp ebx, bpp
+         mov [edi+ebx-1], al    // Write back Raw(x);
+                            // mov does not affect flags; -1 to offset inc ebx
+         jb davgrlp
+         // get # of bytes to alignment
+         mov diff, edi         // take start of row
+         add diff, ebx         // add bpp
+         add diff, 0xf         // add 7 + 8 to incr past alignment boundary
+         and diff, 0xfffffff8  // mask to alignment boundary
+         sub diff, edi         // subtract from start ==> value ebx at alignment
+         jz davggo
+         // fix alignment
+         // Compute the Raw value for the bytes upto the alignment boundary
+         //    Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
+         xor ecx, ecx
+davglp1:
+         xor eax, eax
+         mov cl, [esi + ebx]        // load cl with Prior(x)
+         mov al, [edx + ebx]  // load al with Raw(x-bpp)
+         add ax, cx
+         inc ebx
+         shr ax, 1            // divide by 2
+         add al, [edi+ebx-1]  // Add Avg(x); -1 to offset inc ebx
+         cmp ebx, diff              // Check if at alignment boundary
+         mov [edi+ebx-1], al        // Write back Raw(x);
+                            // mov does not affect flags; -1 to offset inc ebx
+         jb davglp1               // Repeat until at alignment boundary
+davggo:
+         mov eax, FullLength
+         mov ecx, eax
+         sub eax, ebx          // subtract alignment fix
+         and eax, 0x00000007   // calc bytes over mult of 8
+         sub ecx, eax          // drop over bytes from original length
+         mov MMXLength, ecx
+   } // end _asm block
+   // Now do the math for the rest of the row
+   switch ( bpp )
+   {
+      case 3:
+      {
+         ActiveMask.use  = 0x0000000000ffffff;
+         ShiftBpp.use = 24;    // == 3 * 8
+         ShiftRem.use = 40;    // == 64 - 24
+         _asm {
+            // Re-init address pointers and offset
+            movq mm7, ActiveMask
+            mov ebx, diff      // ebx ==> x = offset to alignment boundary
+            movq mm5, LBCarryMask
+            mov edi, row       // edi ==> Avg(x)
+            movq mm4, HBClearMask
+            mov esi, prev_row        // esi ==> Prior(x)
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
+                               // (we correct position in loop below)
+davg3lp:
+            movq mm0, [edi + ebx]      // Load mm0 with Avg(x)
+            // Add (Prev_row/2) to Average
+            movq mm3, mm5
+            psrlq mm2, ShiftRem      // Correct position Raw(x-bpp) data
+            movq mm1, [esi + ebx]    // Load mm1 with Prior(x)
+            movq mm6, mm7
+            pand mm3, mm1      // get lsb for each prev_row byte
+            psrlq mm1, 1       // divide prev_row bytes by 2
+            pand  mm1, mm4     // clear invalid bit 7 of each byte
+            paddb mm0, mm1     // add (Prev_row/2) to Avg for each byte
+            // Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
+            movq mm1, mm3      // now use mm1 for getting LBCarrys
+            pand mm1, mm2      // get LBCarrys for each byte where both
+                               // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1       // divide raw bytes by 2
+            pand  mm2, mm4     // clear invalid bit 7 of each byte
+            paddb mm2, mm1     // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6      // Leave only Active Group 1 bytes to add to Avg
+            paddb mm0, mm2     // add (Raw/2) + LBCarrys to Avg for each Active
+                               //  byte
+            // Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
+            psllq mm6, ShiftBpp  // shift the mm6 mask to cover bytes 3-5
+            movq mm2, mm0        // mov updated Raws to mm2
+            psllq mm2, ShiftBpp  // shift data to position correctly
+            movq mm1, mm3        // now use mm1 for getting LBCarrys
+            pand mm1, mm2      // get LBCarrys for each byte where both
+                               // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1       // divide raw bytes by 2
+            pand  mm2, mm4     // clear invalid bit 7 of each byte
+            paddb mm2, mm1     // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6      // Leave only Active Group 2 bytes to add to Avg
+            paddb mm0, mm2     // add (Raw/2) + LBCarrys to Avg for each Active
+                               //  byte
+
+            // Add 3rd active group (Raw(x-bpp)/2) to Average with LBCarry
+            psllq mm6, ShiftBpp  // shift the mm6 mask to cover the last two
+                                 // bytes
+            movq mm2, mm0        // mov updated Raws to mm2
+            psllq mm2, ShiftBpp  // shift data to position correctly
+                              // Data only needs to be shifted once here to
+                              // get the correct x-bpp offset.
+            movq mm1, mm3     // now use mm1 for getting LBCarrys
+            pand mm1, mm2     // get LBCarrys for each byte where both
+                              // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1      // divide raw bytes by 2
+            pand  mm2, mm4    // clear invalid bit 7 of each byte
+            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6     // Leave only Active Group 2 bytes to add to Avg
+            add ebx, 8
+            paddb mm0, mm2    // add (Raw/2) + LBCarrys to Avg for each Active
+                              // byte
+
+            // Now ready to write back to memory
+            movq [edi + ebx - 8], mm0
+            // Move updated Raw(x) to use as Raw(x-bpp) for next loop
+            cmp ebx, MMXLength
+            movq mm2, mm0     // mov updated Raw(x) to mm2
+            jb davg3lp
+         } // end _asm block
+      }
+      break;
+
+      case 6:
+      case 4:
+      case 7:
+      case 5:
+      {
+         ActiveMask.use  = 0xffffffffffffffff;  // use shift below to clear
+                                                // appropriate inactive bytes
+         ShiftBpp.use = bpp << 3;
+         ShiftRem.use = 64 - ShiftBpp.use;
+         _asm {
+            movq mm4, HBClearMask
+            // Re-init address pointers and offset
+            mov ebx, diff       // ebx ==> x = offset to alignment boundary
+            // Load ActiveMask and clear all bytes except for 1st active group
+            movq mm7, ActiveMask
+            mov edi, row         // edi ==> Avg(x)
+            psrlq mm7, ShiftRem
+            mov esi, prev_row    // esi ==> Prior(x)
+            movq mm6, mm7
+            movq mm5, LBCarryMask
+            psllq mm6, ShiftBpp  // Create mask for 2nd active group
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
+                                 // (we correct position in loop below)
+davg4lp:
+            movq mm0, [edi + ebx]
+            psrlq mm2, ShiftRem  // shift data to position correctly
+            movq mm1, [esi + ebx]
+            // Add (Prev_row/2) to Average
+            movq mm3, mm5
+            pand mm3, mm1     // get lsb for each prev_row byte
+            psrlq mm1, 1      // divide prev_row bytes by 2
+            pand  mm1, mm4    // clear invalid bit 7 of each byte
+            paddb mm0, mm1    // add (Prev_row/2) to Avg for each byte
+            // Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
+            movq mm1, mm3     // now use mm1 for getting LBCarrys
+            pand mm1, mm2     // get LBCarrys for each byte where both
+                              // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1      // divide raw bytes by 2
+            pand  mm2, mm4    // clear invalid bit 7 of each byte
+            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm7     // Leave only Active Group 1 bytes to add to Avg
+            paddb mm0, mm2    // add (Raw/2) + LBCarrys to Avg for each Active
+                              // byte
+            // Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
+            movq mm2, mm0     // mov updated Raws to mm2
+            psllq mm2, ShiftBpp // shift data to position correctly
+            add ebx, 8
+            movq mm1, mm3     // now use mm1 for getting LBCarrys
+            pand mm1, mm2     // get LBCarrys for each byte where both
+                              // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1      // divide raw bytes by 2
+            pand  mm2, mm4    // clear invalid bit 7 of each byte
+            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6     // Leave only Active Group 2 bytes to add to Avg
+            paddb mm0, mm2    // add (Raw/2) + LBCarrys to Avg for each Active
+                              // byte
+            cmp ebx, MMXLength
+            // Now ready to write back to memory
+            movq [edi + ebx - 8], mm0
+            // Prep Raw(x-bpp) for next loop
+            movq mm2, mm0     // mov updated Raws to mm2
+            jb davg4lp
+         } // end _asm block
+      }
+      break;
+      case 2:
+      {
+         ActiveMask.use  = 0x000000000000ffff;
+         ShiftBpp.use = 24;   // == 3 * 8
+         ShiftRem.use = 40;   // == 64 - 24
+         _asm {
+            // Load ActiveMask
+            movq mm7, ActiveMask
+            // Re-init address pointers and offset
+            mov ebx, diff     // ebx ==> x = offset to alignment boundary
+            movq mm5, LBCarryMask
+            mov edi, row      // edi ==> Avg(x)
+            movq mm4, HBClearMask
+            mov esi, prev_row  // esi ==> Prior(x)
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
+                              // (we correct position in loop below)
+davg2lp:
+            movq mm0, [edi + ebx]
+            psllq mm2, ShiftRem  // shift data to position correctly
+            movq mm1, [esi + ebx]
+            // Add (Prev_row/2) to Average
+            movq mm3, mm5
+            pand mm3, mm1     // get lsb for each prev_row byte
+            psrlq mm1, 1      // divide prev_row bytes by 2
+            pand  mm1, mm4    // clear invalid bit 7 of each byte
+            movq mm6, mm7
+            paddb mm0, mm1    // add (Prev_row/2) to Avg for each byte
+            // Add 1st active group (Raw(x-bpp)/2) to Average with LBCarry
+            movq mm1, mm3     // now use mm1 for getting LBCarrys
+            pand mm1, mm2     // get LBCarrys for each byte where both
+                              // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1      // divide raw bytes by 2
+            pand  mm2, mm4    // clear invalid bit 7 of each byte
+            paddb mm2, mm1    // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6     // Leave only Active Group 1 bytes to add to Avg
+            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
+            // Add 2nd active group (Raw(x-bpp)/2) to Average with LBCarry
+            psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 2 & 3
+            movq mm2, mm0       // mov updated Raws to mm2
+            psllq mm2, ShiftBpp // shift data to position correctly
+            movq mm1, mm3       // now use mm1 for getting LBCarrys
+            pand mm1, mm2       // get LBCarrys for each byte where both
+                                // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1        // divide raw bytes by 2
+            pand  mm2, mm4      // clear invalid bit 7 of each byte
+            paddb mm2, mm1      // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6       // Leave only Active Group 2 bytes to add to Avg
+            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
+
+            // Add rdd active group (Raw(x-bpp)/2) to Average with LBCarry
+            psllq mm6, ShiftBpp // shift the mm6 mask to cover bytes 4 & 5
+            movq mm2, mm0       // mov updated Raws to mm2
+            psllq mm2, ShiftBpp // shift data to position correctly
+                                // Data only needs to be shifted once here to
+                                // get the correct x-bpp offset.
+            movq mm1, mm3       // now use mm1 for getting LBCarrys
+            pand mm1, mm2       // get LBCarrys for each byte where both
+                                // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1        // divide raw bytes by 2
+            pand  mm2, mm4      // clear invalid bit 7 of each byte
+            paddb mm2, mm1      // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6       // Leave only Active Group 2 bytes to add to Avg
+            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
+
+            // Add 4th active group (Raw(x-bpp)/2) to Average with LBCarry
+            psllq mm6, ShiftBpp  // shift the mm6 mask to cover bytes 6 & 7
+            movq mm2, mm0        // mov updated Raws to mm2
+            psllq mm2, ShiftBpp  // shift data to position correctly
+                                 // Data only needs to be shifted once here to
+                                 // get the correct x-bpp offset.
+            add ebx, 8
+            movq mm1, mm3    // now use mm1 for getting LBCarrys
+            pand mm1, mm2    // get LBCarrys for each byte where both
+                             // lsb's were == 1 (Only valid for active group)
+            psrlq mm2, 1     // divide raw bytes by 2
+            pand  mm2, mm4   // clear invalid bit 7 of each byte
+            paddb mm2, mm1   // add LBCarrys to (Raw(x-bpp)/2) for each byte
+            pand mm2, mm6    // Leave only Active Group 2 bytes to add to Avg
+            paddb mm0, mm2 // add (Raw/2) + LBCarrys to Avg for each Active byte
+
+            cmp ebx, MMXLength
+            // Now ready to write back to memory
+            movq [edi + ebx - 8], mm0
+            // Prep Raw(x-bpp) for next loop
+            movq mm2, mm0    // mov updated Raws to mm2
+            jb davg2lp
+        } // end _asm block
+      }
+      break;
+
+      case 1:                 // bpp == 1
+      {
+         _asm {
+            // Re-init address pointers and offset
+            mov ebx, diff     // ebx ==> x = offset to alignment boundary
+            mov edi, row      // edi ==> Avg(x)
+            cmp ebx, FullLength  // Test if offset at end of array
+            jnb davg1end
+            // Do Paeth decode for remaining bytes
+            mov esi, prev_row    // esi ==> Prior(x)
+            mov edx, edi
+            xor ecx, ecx         // zero ecx before using cl & cx in loop below
+            sub edx, bpp         // edx ==> Raw(x-bpp)
+davg1lp:
+            // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
+            xor eax, eax
+            mov cl, [esi + ebx]  // load cl with Prior(x)
+            mov al, [edx + ebx]  // load al with Raw(x-bpp)
+            add ax, cx
+            inc ebx
+            shr ax, 1            // divide by 2
+            add al, [edi+ebx-1]  // Add Avg(x); -1 to offset inc ebx
+            cmp ebx, FullLength  // Check if at end of array
+            mov [edi+ebx-1], al  // Write back Raw(x);
+                         // mov does not affect flags; -1 to offset inc ebx
+            jb davg1lp
+davg1end:
+         } // end _asm block
+      }
+      return;
+
+      case 8:             // bpp == 8
+      {
+         _asm {
+            // Re-init address pointers and offset
+            mov ebx, diff           // ebx ==> x = offset to alignment boundary
+            movq mm5, LBCarryMask
+            mov edi, row            // edi ==> Avg(x)
+            movq mm4, HBClearMask
+            mov esi, prev_row       // esi ==> Prior(x)
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm2, [edi + ebx - 8]  // Load previous aligned 8 bytes
+                                // (NO NEED to correct position in loop below)
+davg8lp:
+            movq mm0, [edi + ebx]
+            movq mm3, mm5
+            movq mm1, [esi + ebx]
+            add ebx, 8
+            pand mm3, mm1       // get lsb for each prev_row byte
+            psrlq mm1, 1        // divide prev_row bytes by 2
+            pand mm3, mm2       // get LBCarrys for each byte where both
+                                // lsb's were == 1
+            psrlq mm2, 1        // divide raw bytes by 2
+            pand  mm1, mm4      // clear invalid bit 7 of each byte
+            paddb mm0, mm3      // add LBCarrys to Avg for each byte
+            pand  mm2, mm4      // clear invalid bit 7 of each byte
+            paddb mm0, mm1      // add (Prev_row/2) to Avg for each byte
+            paddb mm0, mm2      // add (Raw/2) to Avg for each byte
+            cmp ebx, MMXLength
+            movq [edi + ebx - 8], mm0
+            movq mm2, mm0       // reuse as Raw(x-bpp)
+            jb davg8lp
+        } // end _asm block
+      }
+      break;
+      default:                  // bpp greater than 8
+      {
+        _asm {
+            movq mm5, LBCarryMask
+            // Re-init address pointers and offset
+            mov ebx, diff       // ebx ==> x = offset to alignment boundary
+            mov edi, row        // edi ==> Avg(x)
+            movq mm4, HBClearMask
+            mov edx, edi
+            mov esi, prev_row   // esi ==> Prior(x)
+            sub edx, bpp        // edx ==> Raw(x-bpp)
+davgAlp:
+            movq mm0, [edi + ebx]
+            movq mm3, mm5
+            movq mm1, [esi + ebx]
+            pand mm3, mm1       // get lsb for each prev_row byte
+            movq mm2, [edx + ebx]
+            psrlq mm1, 1        // divide prev_row bytes by 2
+            pand mm3, mm2       // get LBCarrys for each byte where both
+                                // lsb's were == 1
+            psrlq mm2, 1        // divide raw bytes by 2
+            pand  mm1, mm4      // clear invalid bit 7 of each byte
+            paddb mm0, mm3      // add LBCarrys to Avg for each byte
+            pand  mm2, mm4      // clear invalid bit 7 of each byte
+            paddb mm0, mm1      // add (Prev_row/2) to Avg for each byte
+            add ebx, 8
+            paddb mm0, mm2      // add (Raw/2) to Avg for each byte
+            cmp ebx, MMXLength
+            movq [edi + ebx - 8], mm0
+            jb davgAlp
+        } // end _asm block
+      }
+      break;
+   }                         // end switch ( bpp )
+
+   _asm {
+         // MMX acceleration complete now do clean-up
+         // Check if any remaining bytes left to decode
+         mov ebx, MMXLength    // ebx ==> x = offset bytes remaining after MMX
+         mov edi, row          // edi ==> Avg(x)
+         cmp ebx, FullLength   // Test if offset at end of array
+         jnb davgend
+         // Do Paeth decode for remaining bytes
+         mov esi, prev_row     // esi ==> Prior(x)
+         mov edx, edi
+         xor ecx, ecx          // zero ecx before using cl & cx in loop below
+         sub edx, bpp          // edx ==> Raw(x-bpp)
+davglp2:
+         // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
+         xor eax, eax
+         mov cl, [esi + ebx]   // load cl with Prior(x)
+         mov al, [edx + ebx]   // load al with Raw(x-bpp)
+         add ax, cx
+         inc ebx
+         shr ax, 1              // divide by 2
+         add al, [edi+ebx-1]    // Add Avg(x); -1 to offset inc ebx
+         cmp ebx, FullLength    // Check if at end of array
+         mov [edi+ebx-1], al    // Write back Raw(x);
+                          // mov does not affect flags; -1 to offset inc ebx
+         jb davglp2
+davgend:
+         emms             // End MMX instructions; prep for possible FP instrs.
+   } // end _asm block
+}
+
+// Optimized code for PNG Paeth filter decoder
+void
+png_read_filter_row_mmx_paeth(png_row_infop row_info, png_bytep row,
+                              png_bytep prev_row)
+{
+   png_uint_32 FullLength;
+   png_uint_32 MMXLength;
+   //png_uint_32 len;
+   int bpp;
+   int diff;
+   //int ptemp;
+   int patemp, pbtemp, pctemp;
+
+   bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
+   FullLength  = row_info->rowbytes; // # of bytes to filter
+   _asm
+   {
+         xor ebx, ebx        // ebx ==> x offset
+         mov edi, row
+         xor edx, edx        // edx ==> x-bpp offset
+         mov esi, prev_row
+         xor eax, eax
+
+         // Compute the Raw value for the first bpp bytes
+         // Note: the formula works out to be always
+         //   Paeth(x) = Raw(x) + Prior(x)      where x < bpp
+dpthrlp:
+         mov al, [edi + ebx]
+         add al, [esi + ebx]
+         inc ebx
+         cmp ebx, bpp
+         mov [edi + ebx - 1], al
+         jb dpthrlp
+         // get # of bytes to alignment
+         mov diff, edi         // take start of row
+         add diff, ebx         // add bpp
+         xor ecx, ecx
+         add diff, 0xf         // add 7 + 8 to incr past alignment boundary
+         and diff, 0xfffffff8  // mask to alignment boundary
+         sub diff, edi         // subtract from start ==> value ebx at alignment
+         jz dpthgo
+         // fix alignment
+dpthlp1:
+         xor eax, eax
+         // pav = p - a = (a + b - c) - a = b - c
+         mov al, [esi + ebx]   // load Prior(x) into al
+         mov cl, [esi + edx]   // load Prior(x-bpp) into cl
+         sub eax, ecx          // subtract Prior(x-bpp)
+         mov patemp, eax       // Save pav for later use
+         xor eax, eax
+         // pbv = p - b = (a + b - c) - b = a - c
+         mov al, [edi + edx]   // load Raw(x-bpp) into al
+         sub eax, ecx          // subtract Prior(x-bpp)
+         mov ecx, eax
+         // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+         add eax, patemp       // pcv = pav + pbv
+         // pc = abs(pcv)
+         test eax, 0x80000000
+         jz dpthpca
+         neg eax               // reverse sign of neg values
+dpthpca:
+         mov pctemp, eax       // save pc for later use
+         // pb = abs(pbv)
+         test ecx, 0x80000000
+         jz dpthpba
+         neg ecx               // reverse sign of neg values
+dpthpba:
+         mov pbtemp, ecx       // save pb for later use
+         // pa = abs(pav)
+         mov eax, patemp
+         test eax, 0x80000000
+         jz dpthpaa
+         neg eax               // reverse sign of neg values
+dpthpaa:
+         mov patemp, eax       // save pa for later use
+         // test if pa <= pb
+         cmp eax, ecx
+         jna dpthabb
+         // pa > pb; now test if pb <= pc
+         cmp ecx, pctemp
+         jna dpthbbc
+         // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+         jmp dpthpaeth
+dpthbbc:
+         // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
+         mov cl, [esi + ebx]   // load Prior(x) into cl
+         jmp dpthpaeth
+dpthabb:
+         // pa <= pb; now test if pa <= pc
+         cmp eax, pctemp
+         jna dpthabc
+         // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+         jmp dpthpaeth
+dpthabc:
+         // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
+         mov cl, [edi + edx]  // load Raw(x-bpp) into cl
+dpthpaeth:
+         inc ebx
+         inc edx
+         // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
+         add [edi + ebx - 1], cl
+         cmp ebx, diff
+         jb dpthlp1
+dpthgo:
+         mov ecx, FullLength
+         mov eax, ecx
+         sub eax, ebx          // subtract alignment fix
+         and eax, 0x00000007   // calc bytes over mult of 8
+         sub ecx, eax          // drop over bytes from original length
+         mov MMXLength, ecx
+   } // end _asm block
+   // Now do the math for the rest of the row
+   switch ( bpp )
+   {
+      case 3:
+      {
+         ActiveMask.use = 0x0000000000ffffff;
+         ActiveMaskEnd.use = 0xffff000000000000;
+         ShiftBpp.use = 24;    // == bpp(3) * 8
+         ShiftRem.use = 40;    // == 64 - 24
+         _asm
+         {
+            mov ebx, diff
+            mov edi, row
+            mov esi, prev_row
+            pxor mm0, mm0
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]
+dpth3lp:
+            psrlq mm1, ShiftRem     // shift last 3 bytes to 1st 3 bytes
+            movq mm2, [esi + ebx]   // load b=Prior(x)
+            punpcklbw mm1, mm0      // Unpack High bytes of a
+            movq mm3, [esi+ebx-8]   // Prep c=Prior(x-bpp) bytes
+            punpcklbw mm2, mm0      // Unpack High bytes of b
+            psrlq mm3, ShiftRem     // shift last 3 bytes to 1st 3 bytes
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            punpcklbw mm3, mm0      // Unpack High bytes of c
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4    // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4       // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5    // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5       // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6    // Create mask pcv bytes < 0
+            pand mm0, mm6       // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5    // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6       // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            paddw mm7, mm3
+            pxor mm0, mm0
+            packuswb mm7, mm1
+            movq mm3, [esi + ebx]   // load c=Prior(x-bpp)
+            pand mm7, ActiveMask
+            movq mm2, mm3           // load b=Prior(x) step 1
+            paddb mm7, [edi + ebx]  // add Paeth predictor with Raw(x)
+            punpcklbw mm3, mm0      // Unpack High bytes of c
+            movq [edi + ebx], mm7   // write back updated value
+            movq mm1, mm7           // Now mm1 will be used as Raw(x-bpp)
+            // Now do Paeth for 2nd set of bytes (3-5)
+            psrlq mm2, ShiftBpp     // load b=Prior(x) step 2
+            punpcklbw mm1, mm0      // Unpack High bytes of a
+            pxor mm7, mm7
+            punpcklbw mm2, mm0      // Unpack High bytes of b
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            psubw mm5, mm3
+            psubw mm4, mm3
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) =
+            //       pav + pbv = pbv + pav
+            movq mm6, mm5
+            paddw mm6, mm4
+
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm5       // Create mask pbv bytes < 0
+            pcmpgtw mm7, mm4       // Create mask pav bytes < 0
+            pand mm0, mm5          // Only pbv bytes < 0 in mm0
+            pand mm7, mm4          // Only pav bytes < 0 in mm7
+            psubw mm5, mm0
+            psubw mm4, mm7
+            psubw mm5, mm0
+            psubw mm4, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
+            pand mm0, mm6          // Only pav bytes < 0 in mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5       // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6       // pab > pc?
+            movq mm2, [esi + ebx]  // load b=Prior(x)
+            pand mm3, mm7
+            pandn mm7, mm0
+            pxor mm1, mm1
+            paddw mm7, mm3
+            pxor mm0, mm0
+            packuswb mm7, mm1
+            movq mm3, mm2           // load c=Prior(x-bpp) step 1
+            pand mm7, ActiveMask
+            punpckhbw mm2, mm0      // Unpack High bytes of b
+            psllq mm7, ShiftBpp     // Shift bytes to 2nd group of 3 bytes
+             // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            paddb mm7, [edi + ebx]  // add Paeth predictor with Raw(x)
+            psllq mm3, ShiftBpp     // load c=Prior(x-bpp) step 2
+            movq [edi + ebx], mm7   // write back updated value
+            movq mm1, mm7
+            punpckhbw mm3, mm0      // Unpack High bytes of c
+            psllq mm1, ShiftBpp     // Shift bytes
+                                    // Now mm1 will be used as Raw(x-bpp)
+            // Now do Paeth for 3rd, and final, set of bytes (6-7)
+            pxor mm7, mm7
+            punpckhbw mm1, mm0      // Unpack High bytes of a
+            psubw mm4, mm3
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            pxor mm0, mm0
+            paddw mm6, mm5
+
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4    // Create mask pav bytes < 0
+            pcmpgtw mm7, mm5    // Create mask pbv bytes < 0
+            pand mm0, mm4       // Only pav bytes < 0 in mm7
+            pand mm7, mm5       // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6    // Create mask pcv bytes < 0
+            pand mm0, mm6       // Only pav bytes < 0 in mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5    // pa > pb?
+            movq mm0, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            pandn mm0, mm1
+            pandn mm7, mm4
+            paddw mm0, mm2
+            paddw mm7, mm5
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6    // pab > pc?
+            pand mm3, mm7
+            pandn mm7, mm0
+            paddw mm7, mm3
+            pxor mm1, mm1
+            packuswb mm1, mm7
+            // Step ebx to next set of 8 bytes and repeat loop til done
+            add ebx, 8
+            pand mm1, ActiveMaskEnd
+            paddb mm1, [edi + ebx - 8] // add Paeth predictor with Raw(x)
+
+            cmp ebx, MMXLength
+            pxor mm0, mm0              // pxor does not affect flags
+            movq [edi + ebx - 8], mm1  // write back updated value
+                                 // mm1 will be used as Raw(x-bpp) next loop
+                           // mm3 ready to be used as Prior(x-bpp) next loop
+            jb dpth3lp
+         } // end _asm block
+      }
+      break;
+
+      case 6:
+      case 7:
+      case 5:
+      {
+         ActiveMask.use  = 0x00000000ffffffff;
+         ActiveMask2.use = 0xffffffff00000000;
+         ShiftBpp.use = bpp << 3;    // == bpp * 8
+         ShiftRem.use = 64 - ShiftBpp.use;
+         _asm
+         {
+            mov ebx, diff
+            mov edi, row
+            mov esi, prev_row
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]
+            pxor mm0, mm0
+dpth6lp:
+            // Must shift to position Raw(x-bpp) data
+            psrlq mm1, ShiftRem
+            // Do first set of 4 bytes
+            movq mm3, [esi+ebx-8]      // read c=Prior(x-bpp) bytes
+            punpcklbw mm1, mm0      // Unpack Low bytes of a
+            movq mm2, [esi + ebx]   // load b=Prior(x)
+            punpcklbw mm2, mm0      // Unpack Low bytes of b
+            // Must shift to position Prior(x-bpp) data
+            psrlq mm3, ShiftRem
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            punpcklbw mm3, mm0      // Unpack Low bytes of c
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4    // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4       // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5    // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5       // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6    // Create mask pcv bytes < 0
+            pand mm0, mm6       // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5    // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6    // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            paddw mm7, mm3
+            pxor mm0, mm0
+            packuswb mm7, mm1
+            movq mm3, [esi + ebx - 8]  // load c=Prior(x-bpp)
+            pand mm7, ActiveMask
+            psrlq mm3, ShiftRem
+            movq mm2, [esi + ebx]      // load b=Prior(x) step 1
+            paddb mm7, [edi + ebx]     // add Paeth predictor with Raw(x)
+            movq mm6, mm2
+            movq [edi + ebx], mm7      // write back updated value
+            movq mm1, [edi+ebx-8]
+            psllq mm6, ShiftBpp
+            movq mm5, mm7
+            psrlq mm1, ShiftRem
+            por mm3, mm6
+            psllq mm5, ShiftBpp
+            punpckhbw mm3, mm0         // Unpack High bytes of c
+            por mm1, mm5
+            // Do second set of 4 bytes
+            punpckhbw mm2, mm0         // Unpack High bytes of b
+            punpckhbw mm1, mm0         // Unpack High bytes of a
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4          // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5          // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
+            pand mm0, mm6          // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5       // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6           // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            pxor mm1, mm1
+            paddw mm7, mm3
+            pxor mm0, mm0
+            // Step ex to next set of 8 bytes and repeat loop til done
+            add ebx, 8
+            packuswb mm1, mm7
+            paddb mm1, [edi + ebx - 8]     // add Paeth predictor with Raw(x)
+            cmp ebx, MMXLength
+            movq [edi + ebx - 8], mm1      // write back updated value
+                                // mm1 will be used as Raw(x-bpp) next loop
+            jb dpth6lp
+         } // end _asm block
+      }
+      break;
+
+      case 4:
+      {
+         ActiveMask.use  = 0x00000000ffffffff;
+         _asm {
+            mov ebx, diff
+            mov edi, row
+            mov esi, prev_row
+            pxor mm0, mm0
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]    // Only time should need to read
+                                     //  a=Raw(x-bpp) bytes
+dpth4lp:
+            // Do first set of 4 bytes
+            movq mm3, [esi+ebx-8]    // read c=Prior(x-bpp) bytes
+            punpckhbw mm1, mm0       // Unpack Low bytes of a
+            movq mm2, [esi + ebx]    // load b=Prior(x)
+            punpcklbw mm2, mm0       // Unpack High bytes of b
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            punpckhbw mm3, mm0       // Unpack High bytes of c
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4          // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5          // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
+            pand mm0, mm6          // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5       // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6       // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            paddw mm7, mm3
+            pxor mm0, mm0
+            packuswb mm7, mm1
+            movq mm3, [esi + ebx]      // load c=Prior(x-bpp)
+            pand mm7, ActiveMask
+            movq mm2, mm3              // load b=Prior(x) step 1
+            paddb mm7, [edi + ebx]     // add Paeth predictor with Raw(x)
+            punpcklbw mm3, mm0         // Unpack High bytes of c
+            movq [edi + ebx], mm7      // write back updated value
+            movq mm1, mm7              // Now mm1 will be used as Raw(x-bpp)
+            // Do second set of 4 bytes
+            punpckhbw mm2, mm0         // Unpack Low bytes of b
+            punpcklbw mm1, mm0         // Unpack Low bytes of a
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4          // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5          // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
+            pand mm0, mm6          // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5       // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6       // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            pxor mm1, mm1
+            paddw mm7, mm3
+            pxor mm0, mm0
+            // Step ex to next set of 8 bytes and repeat loop til done
+            add ebx, 8
+            packuswb mm1, mm7
+            paddb mm1, [edi + ebx - 8]     // add Paeth predictor with Raw(x)
+            cmp ebx, MMXLength
+            movq [edi + ebx - 8], mm1      // write back updated value
+                                // mm1 will be used as Raw(x-bpp) next loop
+            jb dpth4lp
+         } // end _asm block
+      }
+      break;
+      case 8:                          // bpp == 8
+      {
+         ActiveMask.use  = 0x00000000ffffffff;
+         _asm {
+            mov ebx, diff
+            mov edi, row
+            mov esi, prev_row
+            pxor mm0, mm0
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]      // Only time should need to read
+                                       //  a=Raw(x-bpp) bytes
+dpth8lp:
+            // Do first set of 4 bytes
+            movq mm3, [esi+ebx-8]      // read c=Prior(x-bpp) bytes
+            punpcklbw mm1, mm0         // Unpack Low bytes of a
+            movq mm2, [esi + ebx]      // load b=Prior(x)
+            punpcklbw mm2, mm0         // Unpack Low bytes of b
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            punpcklbw mm3, mm0         // Unpack Low bytes of c
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4          // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5          // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
+            pand mm0, mm6          // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5       // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6       // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            paddw mm7, mm3
+            pxor mm0, mm0
+            packuswb mm7, mm1
+            movq mm3, [esi+ebx-8]    // read c=Prior(x-bpp) bytes
+            pand mm7, ActiveMask
+            movq mm2, [esi + ebx]    // load b=Prior(x)
+            paddb mm7, [edi + ebx]   // add Paeth predictor with Raw(x)
+            punpckhbw mm3, mm0       // Unpack High bytes of c
+            movq [edi + ebx], mm7    // write back updated value
+            movq mm1, [edi+ebx-8]    // read a=Raw(x-bpp) bytes
+
+            // Do second set of 4 bytes
+            punpckhbw mm2, mm0       // Unpack High bytes of b
+            punpckhbw mm1, mm0       // Unpack High bytes of a
+            // pav = p - a = (a + b - c) - a = b - c
+            movq mm4, mm2
+            // pbv = p - b = (a + b - c) - b = a - c
+            movq mm5, mm1
+            psubw mm4, mm3
+            pxor mm7, mm7
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            movq mm6, mm4
+            psubw mm5, mm3
+            // pa = abs(p-a) = abs(pav)
+            // pb = abs(p-b) = abs(pbv)
+            // pc = abs(p-c) = abs(pcv)
+            pcmpgtw mm0, mm4       // Create mask pav bytes < 0
+            paddw mm6, mm5
+            pand mm0, mm4          // Only pav bytes < 0 in mm7
+            pcmpgtw mm7, mm5       // Create mask pbv bytes < 0
+            psubw mm4, mm0
+            pand mm7, mm5          // Only pbv bytes < 0 in mm0
+            psubw mm4, mm0
+            psubw mm5, mm7
+            pxor mm0, mm0
+            pcmpgtw mm0, mm6       // Create mask pcv bytes < 0
+            pand mm0, mm6          // Only pav bytes < 0 in mm7
+            psubw mm5, mm7
+            psubw mm6, mm0
+            //  test pa <= pb
+            movq mm7, mm4
+            psubw mm6, mm0
+            pcmpgtw mm7, mm5       // pa > pb?
+            movq mm0, mm7
+            // use mm7 mask to merge pa & pb
+            pand mm5, mm7
+            // use mm0 mask copy to merge a & b
+            pand mm2, mm0
+            pandn mm7, mm4
+            pandn mm0, mm1
+            paddw mm7, mm5
+            paddw mm0, mm2
+            //  test  ((pa <= pb)? pa:pb) <= pc
+            pcmpgtw mm7, mm6       // pab > pc?
+            pxor mm1, mm1
+            pand mm3, mm7
+            pandn mm7, mm0
+            pxor mm1, mm1
+            paddw mm7, mm3
+            pxor mm0, mm0
+            // Step ex to next set of 8 bytes and repeat loop til done
+            add ebx, 8
+            packuswb mm1, mm7
+            paddb mm1, [edi + ebx - 8]     // add Paeth predictor with Raw(x)
+            cmp ebx, MMXLength
+            movq [edi + ebx - 8], mm1      // write back updated value
+                            // mm1 will be used as Raw(x-bpp) next loop
+            jb dpth8lp
+         } // end _asm block
+      }
+      break;
+
+      case 1:                // bpp = 1
+      case 2:                // bpp = 2
+      default:               // bpp > 8
+      {
+         _asm {
+            mov ebx, diff
+            cmp ebx, FullLength
+            jnb dpthdend
+            mov edi, row
+            mov esi, prev_row
+            // Do Paeth decode for remaining bytes
+            mov edx, ebx
+            xor ecx, ecx        // zero ecx before using cl & cx in loop below
+            sub edx, bpp        // Set edx = ebx - bpp
+dpthdlp:
+            xor eax, eax
+            // pav = p - a = (a + b - c) - a = b - c
+            mov al, [esi + ebx]        // load Prior(x) into al
+            mov cl, [esi + edx]        // load Prior(x-bpp) into cl
+            sub eax, ecx                 // subtract Prior(x-bpp)
+            mov patemp, eax                 // Save pav for later use
+            xor eax, eax
+            // pbv = p - b = (a + b - c) - b = a - c
+            mov al, [edi + edx]        // load Raw(x-bpp) into al
+            sub eax, ecx                 // subtract Prior(x-bpp)
+            mov ecx, eax
+            // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+            add eax, patemp                 // pcv = pav + pbv
+            // pc = abs(pcv)
+            test eax, 0x80000000
+            jz dpthdpca
+            neg eax                     // reverse sign of neg values
+dpthdpca:
+            mov pctemp, eax             // save pc for later use
+            // pb = abs(pbv)
+            test ecx, 0x80000000
+            jz dpthdpba
+            neg ecx                     // reverse sign of neg values
+dpthdpba:
+            mov pbtemp, ecx             // save pb for later use
+            // pa = abs(pav)
+            mov eax, patemp
+            test eax, 0x80000000
+            jz dpthdpaa
+            neg eax                     // reverse sign of neg values
+dpthdpaa:
+            mov patemp, eax             // save pa for later use
+            // test if pa <= pb
+            cmp eax, ecx
+            jna dpthdabb
+            // pa > pb; now test if pb <= pc
+            cmp ecx, pctemp
+            jna dpthdbbc
+            // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+            mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+            jmp dpthdpaeth
+dpthdbbc:
+            // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
+            mov cl, [esi + ebx]        // load Prior(x) into cl
+            jmp dpthdpaeth
+dpthdabb:
+            // pa <= pb; now test if pa <= pc
+            cmp eax, pctemp
+            jna dpthdabc
+            // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+            mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+            jmp dpthdpaeth
+dpthdabc:
+            // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
+            mov cl, [edi + edx]  // load Raw(x-bpp) into cl
+dpthdpaeth:
+            inc ebx
+            inc edx
+            // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
+            add [edi + ebx - 1], cl
+            cmp ebx, FullLength
+            jb dpthdlp
+dpthdend:
+         } // end _asm block
+      }
+      return;                   // No need to go further with this one
+   }                         // end switch ( bpp )
+   _asm
+   {
+         // MMX acceleration complete now do clean-up
+         // Check if any remaining bytes left to decode
+         mov ebx, MMXLength
+         cmp ebx, FullLength
+         jnb dpthend
+         mov edi, row
+         mov esi, prev_row
+         // Do Paeth decode for remaining bytes
+         mov edx, ebx
+         xor ecx, ecx         // zero ecx before using cl & cx in loop below
+         sub edx, bpp         // Set edx = ebx - bpp
+dpthlp2:
+         xor eax, eax
+         // pav = p - a = (a + b - c) - a = b - c
+         mov al, [esi + ebx]  // load Prior(x) into al
+         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+         sub eax, ecx         // subtract Prior(x-bpp)
+         mov patemp, eax      // Save pav for later use
+         xor eax, eax
+         // pbv = p - b = (a + b - c) - b = a - c
+         mov al, [edi + edx]  // load Raw(x-bpp) into al
+         sub eax, ecx         // subtract Prior(x-bpp)
+         mov ecx, eax
+         // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+         add eax, patemp      // pcv = pav + pbv
+         // pc = abs(pcv)
+         test eax, 0x80000000
+         jz dpthpca2
+         neg eax              // reverse sign of neg values
+dpthpca2:
+         mov pctemp, eax      // save pc for later use
+         // pb = abs(pbv)
+         test ecx, 0x80000000
+         jz dpthpba2
+         neg ecx              // reverse sign of neg values
+dpthpba2:
+         mov pbtemp, ecx      // save pb for later use
+         // pa = abs(pav)
+         mov eax, patemp
+         test eax, 0x80000000
+         jz dpthpaa2
+         neg eax              // reverse sign of neg values
+dpthpaa2:
+         mov patemp, eax      // save pa for later use
+         // test if pa <= pb
+         cmp eax, ecx
+         jna dpthabb2
+         // pa > pb; now test if pb <= pc
+         cmp ecx, pctemp
+         jna dpthbbc2
+         // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+         jmp dpthpaeth2
+dpthbbc2:
+         // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
+         mov cl, [esi + ebx]        // load Prior(x) into cl
+         jmp dpthpaeth2
+dpthabb2:
+         // pa <= pb; now test if pa <= pc
+         cmp eax, pctemp
+         jna dpthabc2
+         // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+         mov cl, [esi + edx]  // load Prior(x-bpp) into cl
+         jmp dpthpaeth2
+dpthabc2:
+         // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
+         mov cl, [edi + edx]  // load Raw(x-bpp) into cl
+dpthpaeth2:
+         inc ebx
+         inc edx
+         // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
+         add [edi + ebx - 1], cl
+         cmp ebx, FullLength
+         jb dpthlp2
+dpthend:
+         emms             // End MMX instructions; prep for possible FP instrs.
+   } // end _asm block
+}
+
+// Optimized code for PNG Sub filter decoder
+void
+png_read_filter_row_mmx_sub(png_row_infop row_info, png_bytep row)
+{
+   //int test;
+   int bpp;
+   png_uint_32 FullLength;
+   png_uint_32 MMXLength;
+   int diff;
+
+   bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
+   FullLength  = row_info->rowbytes - bpp; // # of bytes to filter
+   _asm {
+        mov edi, row
+        mov esi, edi               // lp = row
+        add edi, bpp               // rp = row + bpp
+        xor eax, eax
+        // get # of bytes to alignment
+        mov diff, edi               // take start of row
+        add diff, 0xf               // add 7 + 8 to incr past
+                                        // alignment boundary
+        xor ebx, ebx
+        and diff, 0xfffffff8        // mask to alignment boundary
+        sub diff, edi               // subtract from start ==> value
+                                        //  ebx at alignment
+        jz dsubgo
+        // fix alignment
+dsublp1:
+        mov al, [esi+ebx]
+        add [edi+ebx], al
+        inc ebx
+        cmp ebx, diff
+        jb dsublp1
+dsubgo:
+        mov ecx, FullLength
+        mov edx, ecx
+        sub edx, ebx                  // subtract alignment fix
+        and edx, 0x00000007           // calc bytes over mult of 8
+        sub ecx, edx                  // drop over bytes from length
+        mov MMXLength, ecx
+   } // end _asm block
+
+   // Now do the math for the rest of the row
+   switch ( bpp )
+   {
+        case 3:
+        {
+         ActiveMask.use  = 0x0000ffffff000000;
+         ShiftBpp.use = 24;       // == 3 * 8
+         ShiftRem.use  = 40;      // == 64 - 24
+         _asm {
+            mov edi, row
+            movq mm7, ActiveMask  // Load ActiveMask for 2nd active byte group
+            mov esi, edi              // lp = row
+            add edi, bpp          // rp = row + bpp
+            movq mm6, mm7
+            mov ebx, diff
+            psllq mm6, ShiftBpp   // Move mask in mm6 to cover 3rd active
+                                  // byte group
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]
+dsub3lp:
+            psrlq mm1, ShiftRem   // Shift data for adding 1st bpp bytes
+                          // no need for mask; shift clears inactive bytes
+            // Add 1st active group
+            movq mm0, [edi+ebx]
+            paddb mm0, mm1
+            // Add 2nd active group
+            movq mm1, mm0         // mov updated Raws to mm1
+            psllq mm1, ShiftBpp   // shift data to position correctly
+            pand mm1, mm7         // mask to use only 2nd active group
+            paddb mm0, mm1
+            // Add 3rd active group
+            movq mm1, mm0         // mov updated Raws to mm1
+            psllq mm1, ShiftBpp   // shift data to position correctly
+            pand mm1, mm6         // mask to use only 3rd active group
+            add ebx, 8
+            paddb mm0, mm1
+            cmp ebx, MMXLength
+            movq [edi+ebx-8], mm0     // Write updated Raws back to array
+            // Prep for doing 1st add at top of loop
+            movq mm1, mm0
+            jb dsub3lp
+         } // end _asm block
+      }
+      break;
+
+      case 1:
+      {
+         // Placed here just in case this is a duplicate of the
+         // non-MMX code for the SUB filter in png_read_filter_row above
+         //
+         //         png_bytep rp;
+         //         png_bytep lp;
+         //         png_uint_32 i;
+         //         bpp = (row_info->pixel_depth + 7) >> 3;
+         //         for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
+         //            i < row_info->rowbytes; i++, rp++, lp++)
+         //      {
+         //            *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
+         //      }
+         _asm {
+            mov ebx, diff
+            mov edi, row
+            cmp ebx, FullLength
+            jnb dsub1end
+            mov esi, edi          // lp = row
+            xor eax, eax
+            add edi, bpp      // rp = row + bpp
+dsub1lp:
+            mov al, [esi+ebx]
+            add [edi+ebx], al
+            inc ebx
+            cmp ebx, FullLength
+            jb dsub1lp
+dsub1end:
+         } // end _asm block
+      }
+      return;
+
+      case 6:
+      case 7:
+      case 4:
+      case 5:
+      {
+         ShiftBpp.use = bpp << 3;
+         ShiftRem.use = 64 - ShiftBpp.use;
+         _asm {
+            mov edi, row
+            mov ebx, diff
+            mov esi, edi               // lp = row
+            add edi, bpp           // rp = row + bpp
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]
+dsub4lp:
+            psrlq mm1, ShiftRem // Shift data for adding 1st bpp bytes
+                          // no need for mask; shift clears inactive bytes
+            movq mm0, [edi+ebx]
+            paddb mm0, mm1
+            // Add 2nd active group
+            movq mm1, mm0          // mov updated Raws to mm1
+            psllq mm1, ShiftBpp    // shift data to position correctly
+                                   // there is no need for any mask
+                                   // since shift clears inactive bits/bytes
+            add ebx, 8
+            paddb mm0, mm1
+            cmp ebx, MMXLength
+            movq [edi+ebx-8], mm0
+            movq mm1, mm0          // Prep for doing 1st add at top of loop
+            jb dsub4lp
+         } // end _asm block
+      }
+      break;
+
+      case 2:
+      {
+         ActiveMask.use  = 0x00000000ffff0000;
+         ShiftBpp.use = 16;       // == 2 * 8
+         ShiftRem.use = 48;       // == 64 - 16
+         _asm {
+            movq mm7, ActiveMask  // Load ActiveMask for 2nd active byte group
+            mov ebx, diff
+            movq mm6, mm7
+            mov edi, row
+            psllq mm6, ShiftBpp     // Move mask in mm6 to cover 3rd active
+                                    //  byte group
+            mov esi, edi            // lp = row
+            movq mm5, mm6
+            add edi, bpp            // rp = row + bpp
+            psllq mm5, ShiftBpp     // Move mask in mm5 to cover 4th active
+                                    //  byte group
+            // PRIME the pump (load the first Raw(x-bpp) data set
+            movq mm1, [edi+ebx-8]
+dsub2lp:
+            // Add 1st active group
+            psrlq mm1, ShiftRem     // Shift data for adding 1st bpp bytes
+                                    // no need for mask; shift clears inactive
+                                    //  bytes
+            movq mm0, [edi+ebx]
+            paddb mm0, mm1
+            // Add 2nd active group
+            movq mm1, mm0           // mov updated Raws to mm1
+            psllq mm1, ShiftBpp     // shift data to position correctly
+            pand mm1, mm7           // mask to use only 2nd active group
+            paddb mm0, mm1
+            // Add 3rd active group
+            movq mm1, mm0           // mov updated Raws to mm1
+            psllq mm1, ShiftBpp     // shift data to position correctly
+            pand mm1, mm6           // mask to use only 3rd active group
+            paddb mm0, mm1
+            // Add 4th active group
+            movq mm1, mm0           // mov updated Raws to mm1
+            psllq mm1, ShiftBpp     // shift data to position correctly
+            pand mm1, mm5           // mask to use only 4th active group
+            add ebx, 8
+            paddb mm0, mm1
+            cmp ebx, MMXLength
+            movq [edi+ebx-8], mm0   // Write updated Raws back to array
+            movq mm1, mm0           // Prep for doing 1st add at top of loop
+            jb dsub2lp
+         } // end _asm block
+      }
+      break;
+      case 8:
+      {
+         _asm {
+            mov edi, row
+            mov ebx, diff
+            mov esi, edi            // lp = row
+            add edi, bpp            // rp = row + bpp
+            mov ecx, MMXLength
+            movq mm7, [edi+ebx-8]   // PRIME the pump (load the first
+                                    // Raw(x-bpp) data set
+            and ecx, 0x0000003f     // calc bytes over mult of 64
+dsub8lp:
+            movq mm0, [edi+ebx]     // Load Sub(x) for 1st 8 bytes
+            paddb mm0, mm7
+            movq mm1, [edi+ebx+8]   // Load Sub(x) for 2nd 8 bytes
+            movq [edi+ebx], mm0    // Write Raw(x) for 1st 8 bytes
+                                   // Now mm0 will be used as Raw(x-bpp) for
+                                   // the 2nd group of 8 bytes.  This will be
+                                   // repeated for each group of 8 bytes with
+                                   // the 8th group being used as the Raw(x-bpp)
+                                   // for the 1st group of the next loop.
+            paddb mm1, mm0
+            movq mm2, [edi+ebx+16]  // Load Sub(x) for 3rd 8 bytes
+            movq [edi+ebx+8], mm1   // Write Raw(x) for 2nd 8 bytes
+            paddb mm2, mm1
+            movq mm3, [edi+ebx+24]  // Load Sub(x) for 4th 8 bytes
+            movq [edi+ebx+16], mm2  // Write Raw(x) for 3rd 8 bytes
+            paddb mm3, mm2
+            movq mm4, [edi+ebx+32]  // Load Sub(x) for 5th 8 bytes
+            movq [edi+ebx+24], mm3  // Write Raw(x) for 4th 8 bytes
+            paddb mm4, mm3
+            movq mm5, [edi+ebx+40]  // Load Sub(x) for 6th 8 bytes
+            movq [edi+ebx+32], mm4  // Write Raw(x) for 5th 8 bytes
+            paddb mm5, mm4
+            movq mm6, [edi+ebx+48]  // Load Sub(x) for 7th 8 bytes
+            movq [edi+ebx+40], mm5  // Write Raw(x) for 6th 8 bytes
+            paddb mm6, mm5
+            movq mm7, [edi+ebx+56]  // Load Sub(x) for 8th 8 bytes
+            movq [edi+ebx+48], mm6  // Write Raw(x) for 7th 8 bytes
+            add ebx, 64
+            paddb mm7, mm6
+            cmp ebx, ecx
+            movq [edi+ebx-8], mm7   // Write Raw(x) for 8th 8 bytes
+            jb dsub8lp
+            cmp ebx, MMXLength
+            jnb dsub8lt8
+dsub8lpA:
+            movq mm0, [edi+ebx]
+            add ebx, 8
+            paddb mm0, mm7
+            cmp ebx, MMXLength
+            movq [edi+ebx-8], mm0   // use -8 to offset early add to ebx
+            movq mm7, mm0           // Move calculated Raw(x) data to mm1 to
+                                    // be the new Raw(x-bpp) for the next loop
+            jb dsub8lpA
+dsub8lt8:
+         } // end _asm block
+      }
+      break;
+
+      default:                // bpp greater than 8 bytes
+      {
+         _asm {
+            mov ebx, diff
+            mov edi, row
+            mov esi, edi           // lp = row
+            add edi, bpp           // rp = row + bpp
+dsubAlp:
+            movq mm0, [edi+ebx]
+            movq mm1, [esi+ebx]
+            add ebx, 8
+            paddb mm0, mm1
+            cmp ebx, MMXLength
+            movq [edi+ebx-8], mm0  // mov does not affect flags; -8 to offset
+                                   //  add ebx
+            jb dsubAlp
+         } // end _asm block
+      }
+      break;
+
+   } // end switch ( bpp )
+
+   _asm {
+        mov ebx, MMXLength
+        mov edi, row
+        cmp ebx, FullLength
+        jnb dsubend
+        mov esi, edi               // lp = row
+        xor eax, eax
+        add edi, bpp               // rp = row + bpp
+dsublp2:
+        mov al, [esi+ebx]
+        add [edi+ebx], al
+        inc ebx
+        cmp ebx, FullLength
+        jb dsublp2
+dsubend:
+        emms             // End MMX instructions; prep for possible FP instrs.
+   } // end _asm block
+}
+
+// Optimized code for PNG Up filter decoder
+void
+png_read_filter_row_mmx_up(png_row_infop row_info, png_bytep row,
+   png_bytep prev_row)
+{
+   png_uint_32 len;
+   len  = row_info->rowbytes;       // # of bytes to filter
+   _asm {
+      mov edi, row
+      // get # of bytes to alignment
+      mov ecx, edi
+      xor ebx, ebx
+      add ecx, 0x7
+      xor eax, eax
+      and ecx, 0xfffffff8
+      mov esi, prev_row
+      sub ecx, edi
+      jz dupgo
+      // fix alignment
+duplp1:
+      mov al, [edi+ebx]
+      add al, [esi+ebx]
+      inc ebx
+      cmp ebx, ecx
+      mov [edi + ebx-1], al  // mov does not affect flags; -1 to offset inc ebx
+      jb duplp1
+dupgo:
+      mov ecx, len
+      mov edx, ecx
+      sub edx, ebx                  // subtract alignment fix
+      and edx, 0x0000003f           // calc bytes over mult of 64
+      sub ecx, edx                  // drop over bytes from length
+      // Unrolled loop - use all MMX registers and interleave to reduce
+      // number of branch instructions (loops) and reduce partial stalls
+duploop:
+      movq mm1, [esi+ebx]
+      movq mm0, [edi+ebx]
+      movq mm3, [esi+ebx+8]
+      paddb mm0, mm1
+      movq mm2, [edi+ebx+8]
+      movq [edi+ebx], mm0
+      paddb mm2, mm3
+      movq mm5, [esi+ebx+16]
+      movq [edi+ebx+8], mm2
+      movq mm4, [edi+ebx+16]
+      movq mm7, [esi+ebx+24]
+      paddb mm4, mm5
+      movq mm6, [edi+ebx+24]
+      movq [edi+ebx+16], mm4
+      paddb mm6, mm7
+      movq mm1, [esi+ebx+32]
+      movq [edi+ebx+24], mm6
+      movq mm0, [edi+ebx+32]
+      movq mm3, [esi+ebx+40]
+      paddb mm0, mm1
+      movq mm2, [edi+ebx+40]
+      movq [edi+ebx+32], mm0
+      paddb mm2, mm3
+      movq mm5, [esi+ebx+48]
+      movq [edi+ebx+40], mm2
+      movq mm4, [edi+ebx+48]
+      movq mm7, [esi+ebx+56]
+      paddb mm4, mm5
+      movq mm6, [edi+ebx+56]
+      movq [edi+ebx+48], mm4
+      add ebx, 64
+      paddb mm6, mm7
+      cmp ebx, ecx
+      movq [edi+ebx-8], mm6 // (+56)movq does not affect flags;
+                                     // -8 to offset add ebx
+      jb duploop
+
+      cmp edx, 0                     // Test for bytes over mult of 64
+      jz dupend
+
+
+      // 2 lines added by lcreeve@netins.net
+      // (mail 11 Jul 98 in png-implement list)
+      cmp edx, 8 //test for less than 8 bytes
+      jb duplt8
+
+
+      add ecx, edx
+      and edx, 0x00000007           // calc bytes over mult of 8
+      sub ecx, edx                  // drop over bytes from length
+      jz duplt8
+      // Loop using MMX registers mm0 & mm1 to update 8 bytes simultaneously
+duplpA:
+      movq mm1, [esi+ebx]
+      movq mm0, [edi+ebx]
+      add ebx, 8
+      paddb mm0, mm1
+      cmp ebx, ecx
+      movq [edi+ebx-8], mm0 // movq does not affect flags; -8 to offset add ebx
+      jb duplpA
+      cmp edx, 0            // Test for bytes over mult of 8
+      jz dupend
+duplt8:
+      xor eax, eax
+      add ecx, edx          // move over byte count into counter
+      // Loop using x86 registers to update remaining bytes
+duplp2:
+      mov al, [edi + ebx]
+      add al, [esi + ebx]
+      inc ebx
+      cmp ebx, ecx
+      mov [edi + ebx-1], al // mov does not affect flags; -1 to offset inc ebx
+      jb duplp2
+dupend:
+      // Conversion of filtered row completed
+      emms          // End MMX instructions; prep for possible FP instrs.
+   } // end _asm block
+}
+
+
+// Optimized png_read_filter_row routines
+void
+png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
+   row, png_bytep prev_row, int filter)
+{
+#ifdef PNG_DEBUG
+   char filnm[6];
+#endif
+   #define UseMMX (1)
+
+   if (mmx_supported == 2)
+       mmx_supported = mmxsupport();
+
+   if (!mmx_supported)
+   {
+       png_read_filter_row_c(png_ptr, row_info, row, prev_row, filter);
+       return ;
+   }
+
+#ifdef PNG_DEBUG
+   png_debug(1, "in png_read_filter_row\n");
+   png_debug1(0,"%s, ", (UseMMX?"MMX":"x86"));
+   switch (filter)
+   {
+      case 0: sprintf(filnm, "None ");
+         break;
+      case 1: sprintf(filnm, "Sub  ");
+         break;
+      case 2: sprintf(filnm, "Up   ");
+         break;
+      case 3: sprintf(filnm, "Avg  ");
+         break;
+      case 4: sprintf(filnm, "Paeth");
+         break;
+      default: sprintf(filnm, "Unknw");
+         break;
+   }
+   png_debug2(0,"row=%5d, %s, ", png_ptr->row_number, filnm);
+   png_debug2(0, "pd=%2d, b=%d, ", (int)row_info->pixel_depth,
+      (int)((row_info->pixel_depth + 7) >> 3));
+   png_debug1(0,"len=%8d, ", row_info->rowbytes);
+#endif
+
+   switch (filter)
+   {
+      case PNG_FILTER_VALUE_NONE:
+         break;
+      case PNG_FILTER_VALUE_SUB:
+      {
+         if ( UseMMX && (row_info->pixel_depth > 8) &&
+            (row_info->rowbytes >= 128) )
+         {
+            png_read_filter_row_mmx_sub(row_info, row);
+         }  //end if UseMMX
+         else
+         {
+            png_uint_32 i;
+            png_uint_32 istop = row_info->rowbytes;
+            png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+            png_bytep rp = row + bpp;
+            png_bytep lp = row;
+
+            for (i = bpp; i < istop; i++)
+            {
+               *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
+               rp++;
+            }
+         }  //end !UseMMX
+         break;
+      }
+      case PNG_FILTER_VALUE_UP:
+      {
+         if ( UseMMX && (row_info->pixel_depth > 8) &&
+             (row_info->rowbytes >= 128) )
+         {
+            png_read_filter_row_mmx_up(row_info, row, prev_row);
+         }  //end if UseMMX
+         else
+         {
+            png_bytep rp;
+            png_bytep pp;
+            png_uint_32 i;
+            for (i = 0, rp = row, pp = prev_row;
+               i < row_info->rowbytes; i++, rp++, pp++)
+            {
+                  *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
+            }
+         }  //end !UseMMX
+         break;
+      }
+      case PNG_FILTER_VALUE_AVG:
+      {
+         if ( UseMMX && (row_info->pixel_depth > 8) &&
+             (row_info->rowbytes >= 128) )
+         {
+            png_read_filter_row_mmx_avg(row_info, row, prev_row);
+         }  //end if UseMMX
+         else
+         {
+            png_uint_32 i;
+            png_bytep rp = row;
+            png_bytep pp = prev_row;
+            png_bytep lp = row;
+            png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+            png_uint_32 istop = row_info->rowbytes - bpp;
+
+            for (i = 0; i < bpp; i++)
+            {
+               *rp = (png_byte)(((int)(*rp) +
+                  ((int)(*pp++) >> 1)) & 0xff);
+               rp++;
+            }
+
+            for (i = 0; i < istop; i++)
+            {
+               *rp = (png_byte)(((int)(*rp) +
+                  ((int)(*pp++ + *lp++) >> 1)) & 0xff);
+               rp++;
+            }
+         }  //end !UseMMX
+         break;
+      }
+      case PNG_FILTER_VALUE_PAETH:
+      {
+         if ( UseMMX && (row_info->pixel_depth > 8) &&
+             (row_info->rowbytes >= 128) )
+         {
+            png_read_filter_row_mmx_paeth(row_info, row, prev_row);
+         }  //end if UseMMX
+         else
+         {
+            png_uint_32 i;
+            png_bytep rp = row;
+            png_bytep pp = prev_row;
+            png_bytep lp = row;
+            png_bytep cp = prev_row;
+            png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+            png_uint_32 istop=row_info->rowbytes - bpp;
+
+            for (i = 0; i < bpp; i++)
+            {
+               *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+               rp++;
+            }
+
+            for (i = 0; i < istop; i++)   // use leftover rp,pp
+            {
+               int a, b, c, pa, pb, pc, p;
+
+               a = *lp++;
+               b = *pp++;
+               c = *cp++;
+
+               p = b - c;
+               pc = a - c;
+
+#ifdef PNG_USE_ABS
+               pa = abs(p);
+               pb = abs(pc);
+               pc = abs(p + pc);
+#else
+               pa = p < 0 ? -p : p;
+               pb = pc < 0 ? -pc : pc;
+               pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+               /*
+                  if (pa <= pb && pa <= pc)
+                     p = a;
+                  else if (pb <= pc)
+                     p = b;
+                  else
+                     p = c;
+                */
+
+               p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+               *rp = (png_byte)(((int)(*rp) + p) & 0xff);
+               rp++;
+            }
+         }  //end !UseMMX
+         break;
+      }
+      default:
+         png_error(png_ptr, "Bad adaptive filter type");
+         break;
+   }
+}
+#endif