| /* |
| MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples |
| Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr) |
| This code is licensed under the LGPL (see COPYING for details) |
| |
| Assumes buffer size in bytes is a multiple of 16 |
| Assumes SDL_MIX_MAXVOLUME = 128 |
| */ |
| |
| |
| /*********************************************** |
| * Mixing for 16 bit signed buffers |
| ***********************************************/ |
| |
| #if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT) |
| void SDL_MixAudio_MMX_S16(char* dst,char* src,unsigned int size,int volume) |
| { |
| __asm__ __volatile__ ( |
| |
| " movl %3,%%eax\n" // eax = volume |
| |
| " movl %2,%%edx\n" // edx = size |
| |
| " shrl $4,%%edx\n" // process 16 bytes per iteration = 8 samples |
| |
| " jz .endS16\n" |
| |
| " pxor %%mm0,%%mm0\n" |
| |
| " movd %%eax,%%mm0\n" |
| " movq %%mm0,%%mm1\n" |
| " psllq $16,%%mm0\n" |
| " por %%mm1,%%mm0\n" |
| " psllq $16,%%mm0\n" |
| " por %%mm1,%%mm0\n" |
| " psllq $16,%%mm0\n" |
| " por %%mm1,%%mm0\n" // mm0 = vol|vol|vol|vol |
| |
| ".align 16\n" |
| " .mixloopS16:\n" |
| |
| " movq (%1),%%mm1\n" // mm1 = a|b|c|d |
| |
| " movq %%mm1,%%mm2\n" // mm2 = a|b|c|d |
| |
| " movq 8(%1),%%mm4\n" // mm4 = e|f|g|h |
| |
| // pré charger le buffer dst dans mm7 |
| " movq (%0),%%mm7\n" // mm7 = dst[0]" |
| |
| // multiplier par le volume |
| " pmullw %%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v) |
| |
| " pmulhw %%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v) |
| " movq %%mm4,%%mm5\n" // mm5 = e|f|g|h |
| |
| " pmullw %%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v) |
| |
| " pmulhw %%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v) |
| " movq %%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v) |
| |
| " punpckhwd %%mm2,%%mm1\n" // mm1 = a*v|b*v |
| |
| " movq %%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v) |
| " punpcklwd %%mm2,%%mm3\n" // mm3 = c*v|d*v |
| |
| " punpckhwd %%mm5,%%mm4\n" // mm4 = e*f|f*v |
| |
| " punpcklwd %%mm5,%%mm6\n" // mm6 = g*v|h*v |
| |
| // pré charger le buffer dst dans mm5 |
| " movq 8(%0),%%mm5\n" // mm5 = dst[1] |
| |
| // diviser par 128 |
| " psrad $7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME |
| " add $16,%1\n" |
| |
| " psrad $7,%%mm3\n" // mm3 = c*v/128|d*v/128 |
| |
| " psrad $7,%%mm4\n" // mm4 = e*v/128|f*v/128 |
| |
| // mm1 = le sample avec le volume modifié |
| " packssdw %%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v) |
| |
| " psrad $7,%%mm6\n" // mm6= g*v/128|h*v/128 |
| " paddsw %%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst |
| |
| // mm4 = le sample avec le volume modifié |
| " packssdw %%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v) |
| " movq %%mm3,(%0)\n" |
| |
| " paddsw %%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst |
| |
| " movq %%mm6,8(%0)\n" |
| |
| " add $16,%0\n" |
| |
| " dec %%edx\n" |
| |
| " jnz .mixloopS16\n" |
| |
| " emms\n" |
| |
| ".endS16:\n" |
| : |
| : "r" (dst), "r"(src),"m"(size), |
| "m"(volume) |
| : "eax","edx","memory" |
| ); |
| } |
| |
| |
| |
| //////////////////////////////////////////////// |
| // Mixing for 8 bit signed buffers |
| //////////////////////////////////////////////// |
| |
| void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume) |
| { |
| __asm__ __volatile__ ( |
| |
| " movl %3,%%eax\n" // eax = volume |
| |
| " movd %%eax,%%mm0\n" |
| " movq %%mm0,%%mm1\n" |
| " psllq $16,%%mm0\n" |
| " por %%mm1,%%mm0\n" |
| " psllq $16,%%mm0\n" |
| " por %%mm1,%%mm0\n" |
| " psllq $16,%%mm0\n" |
| " por %%mm1,%%mm0\n" |
| |
| " movl %2,%%edx\n" // edx = size |
| " shr $3,%%edx\n" // process 8 bytes per iteration = 8 samples |
| |
| " cmp $0,%%edx\n" |
| " je .endS8\n" |
| |
| ".align 16\n" |
| " .mixloopS8:\n" |
| |
| " pxor %%mm2,%%mm2\n" // mm2 = 0 |
| " movq (%1),%%mm1\n" // mm1 = a|b|c|d|e|f|g|h |
| |
| " movq %%mm1,%%mm3\n" // mm3 = a|b|c|d|e|f|g|h |
| |
| // on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0 |
| " pcmpgtb %%mm1,%%mm2\n" // mm2 = 11111111|00000000|00000000.... |
| |
| " punpckhbw %%mm2,%%mm1\n" // mm1 = 0|a|0|b|0|c|0|d |
| |
| " punpcklbw %%mm2,%%mm3\n" // mm3 = 0|e|0|f|0|g|0|h |
| " movq (%0),%%mm2\n" // mm2 = destination |
| |
| " pmullw %%mm0,%%mm1\n" // mm1 = v*a|v*b|v*c|v*d |
| " add $8,%1\n" |
| |
| " pmullw %%mm0,%%mm3\n" // mm3 = v*e|v*f|v*g|v*h |
| " psraw $7,%%mm1\n" // mm1 = v*a/128|v*b/128|v*c/128|v*d/128 |
| |
| " psraw $7,%%mm3\n" // mm3 = v*e/128|v*f/128|v*g/128|v*h/128 |
| |
| " packsswb %%mm1,%%mm3\n" // mm1 = v*a/128|v*b/128|v*c/128|v*d/128|v*e/128|v*f/128|v*g/128|v*h/128 |
| |
| " paddsb %%mm2,%%mm3\n" // add to destination buffer |
| |
| " movq %%mm3,(%0)\n" // store back to ram |
| " add $8,%0\n" |
| |
| " dec %%edx\n" |
| |
| " jnz .mixloopS8\n" |
| |
| ".endS8:\n" |
| " emms\n" |
| : |
| : "r" (dst), "r"(src),"m"(size), |
| "m"(volume) |
| : "eax","edx","memory" |
| ); |
| } |
| #endif |
| |
