refactor SkBitmapProcState_opts.h a bit
Shouldn't be any major change in here, and the only codegen change
should be the easy-to-predict branch on alpha < 256. This is mostly
about makings sure I understand and can read the code.
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I3e6260be76595275ba177551cbb8f4a84e4970ec
Reviewed-on: https://skia-review.googlesource.com/c/171585
Auto-Submit: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Herb Derby <herb@google.com>
diff --git a/src/opts/SkBitmapProcState_opts.h b/src/opts/SkBitmapProcState_opts.h
index adc03c5..4d6e573 100644
--- a/src/opts/SkBitmapProcState_opts.h
+++ b/src/opts/SkBitmapProcState_opts.h
@@ -27,18 +27,19 @@
namespace SK_OPTS_NS {
-#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSSE3
- // This same basic packing scheme is used throughout the file.
- static void decode_packed_coordinates_and_weight(uint32_t packed, int* v0, int* v1, int* w) {
- // The top 14 bits are the integer coordinate x0 or y0.
- *v0 = packed >> 18;
+// This same basic packing scheme is used throughout the file.
+static void decode_packed_coordinates_and_weight(uint32_t packed, int* v0, int* v1, int* w) {
+ // The top 14 bits are the integer coordinate x0 or y0.
+ *v0 = packed >> 18;
- // The bottom 14 bits are the integer coordinate x1 or y1.
- *v1 = packed & 0x3fff;
+ // The bottom 14 bits are the integer coordinate x1 or y1.
+ *v1 = packed & 0x3fff;
- // The middle 4 bits are the interpolating factor between the two, i.e. the weight for v1.
- *w = (packed >> 14) & 0xf;
- }
+ // The middle 4 bits are the interpolating factor between the two, i.e. the weight for v1.
+ *w = (packed >> 14) & 0xf;
+}
+
+#if 1 && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSSE3
// As above, 4x.
static void decode_packed_coordinates_and_weight(__m128i packed,
@@ -180,7 +181,7 @@
}
-#elif SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
+#elif 1 && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
// TODO(mtklein): clean up this code, use decode_packed_coordinates_and_weight(), etc.
@@ -192,112 +193,63 @@
SkASSERT(kN32_SkColorType == s.fPixmap.colorType());
SkASSERT(s.fAlphaScale <= 256);
- const char* srcAddr = static_cast<const char*>(s.fPixmap.addr());
- size_t rb = s.fPixmap.rowBytes();
- uint32_t XY = *xy++;
- unsigned y0 = XY >> 14;
- const uint32_t* row0 = reinterpret_cast<const uint32_t*>(srcAddr + (y0 >> 4) * rb);
- const uint32_t* row1 = reinterpret_cast<const uint32_t*>(srcAddr + (XY & 0x3FFF) * rb);
- unsigned subY = y0 & 0xF;
+ int y0, y1, wy;
+ decode_packed_coordinates_and_weight(*xy++, &y0, &y1, &wy);
- // ( 0, 0, 0, 0, 0, 0, 0, 16)
- __m128i sixteen = _mm_cvtsi32_si128(16);
+ auto row0 = (const uint32_t*)( (const char*)s.fPixmap.addr() + y0 * s.fPixmap.rowBytes() ),
+ row1 = (const uint32_t*)( (const char*)s.fPixmap.addr() + y1 * s.fPixmap.rowBytes() );
- // ( 0, 0, 0, 0, 16, 16, 16, 16)
- sixteen = _mm_shufflelo_epi16(sixteen, 0);
+ // We'll put one pixel in the low 4 16-bit lanes to line up with wy,
+ // and another in the upper 4 16-bit lanes to line up with 16 - wy.
+ const __m128i allY = _mm_unpacklo_epi64(_mm_set1_epi16( wy),
+ _mm_set1_epi16(16-wy));
- // ( 0, 0, 0, 0, 0, 0, 0, y)
- __m128i allY = _mm_cvtsi32_si128(subY);
+ while (count --> 0) {
+ int x0, x1, wx;
+ decode_packed_coordinates_and_weight(*xy++, &x0, &x1, &wx);
- // ( 0, 0, 0, 0, y, y, y, y)
- allY = _mm_shufflelo_epi16(allY, 0);
+ // Load the 4 pixels we're interpolating.
+ const __m128i a00 = _mm_cvtsi32_si128(row0[x0]),
+ a01 = _mm_cvtsi32_si128(row0[x1]),
+ a10 = _mm_cvtsi32_si128(row1[x0]),
+ a11 = _mm_cvtsi32_si128(row1[x1]);
- // ( 0, 0, 0, 0, 16-y, 16-y, 16-y, 16-y)
- __m128i negY = _mm_sub_epi16(sixteen, allY);
+ // Line up low-x pixels a00 and a10 with allY.
+ __m128i a00a10 = _mm_unpacklo_epi8(_mm_unpacklo_epi32(a10, a00),
+ _mm_setzero_si128());
- // (16-y, 16-y, 16-y, 16-y, y, y, y, y)
- allY = _mm_unpacklo_epi64(allY, negY);
-
- // (16, 16, 16, 16, 16, 16, 16, 16 )
- sixteen = _mm_shuffle_epi32(sixteen, 0);
-
- // ( 0, 0, 0, 0, 0, 0, 0, 0)
- __m128i zero = _mm_setzero_si128();
-
- // ( alpha, alpha, alpha, alpha, alpha, alpha, alpha, alpha )
- __m128i alpha = _mm_set1_epi16(s.fAlphaScale);
-
- do {
- uint32_t XX = *xy++; // x0:14 | 4 | x1:14
- unsigned x0 = XX >> 18;
- unsigned x1 = XX & 0x3FFF;
-
- // (0, 0, 0, 0, 0, 0, 0, x)
- __m128i allX = _mm_cvtsi32_si128((XX >> 14) & 0x0F);
-
- // (0, 0, 0, 0, x, x, x, x)
- allX = _mm_shufflelo_epi16(allX, 0);
-
- // (x, x, x, x, x, x, x, x)
- allX = _mm_shuffle_epi32(allX, 0);
-
- // (16-x, 16-x, 16-x, 16-x, 16-x, 16-x, 16-x)
- __m128i negX = _mm_sub_epi16(sixteen, allX);
-
- // Load 4 samples (pixels).
- __m128i a00 = _mm_cvtsi32_si128(row0[x0]);
- __m128i a01 = _mm_cvtsi32_si128(row0[x1]);
- __m128i a10 = _mm_cvtsi32_si128(row1[x0]);
- __m128i a11 = _mm_cvtsi32_si128(row1[x1]);
-
- // (0, 0, a00, a10)
- __m128i a00a10 = _mm_unpacklo_epi32(a10, a00);
-
- // Expand to 16 bits per component.
- a00a10 = _mm_unpacklo_epi8(a00a10, zero);
-
- // ((a00 * (16-y)), (a10 * y)).
+ // Scale by allY and 16-wx.
a00a10 = _mm_mullo_epi16(a00a10, allY);
+ a00a10 = _mm_mullo_epi16(a00a10, _mm_set1_epi16(16-wx));
- // (a00 * (16-y) * (16-x), a10 * y * (16-x)).
- a00a10 = _mm_mullo_epi16(a00a10, negX);
- // (0, 0, a01, a10)
- __m128i a01a11 = _mm_unpacklo_epi32(a11, a01);
+ // Line up high-x pixels a01 and a11 with allY.
+ __m128i a01a11 = _mm_unpacklo_epi8(_mm_unpacklo_epi32(a11, a01),
+ _mm_setzero_si128());
- // Expand to 16 bits per component.
- a01a11 = _mm_unpacklo_epi8(a01a11, zero);
-
- // (a01 * (16-y)), (a11 * y)
+ // Scale by allY and wx.
a01a11 = _mm_mullo_epi16(a01a11, allY);
+ a01a11 = _mm_mullo_epi16(a01a11, _mm_set1_epi16(wx));
- // (a01 * (16-y) * x), (a11 * y * x)
- a01a11 = _mm_mullo_epi16(a01a11, allX);
- // (a00*w00 + a01*w01, a10*w10 + a11*w11)
- __m128i sum = _mm_add_epi16(a00a10, a01a11);
+ // Add the two intermediates, summing across in one direction.
+ __m128i halves = _mm_add_epi16(a00a10, a01a11);
- // (DC, a00*w00 + a01*w01)
- __m128i shifted = _mm_shuffle_epi32(sum, 0xEE);
+ // Add the two halves to each other to sum in the other direction.
+ __m128i sum = _mm_add_epi16(halves, _mm_srli_si128(halves, 8));
- // (DC, a00*w00 + a01*w01 + a10*w10 + a11*w11)
- sum = _mm_add_epi16(sum, shifted);
-
- // Divide each 16 bit component by 256.
+ // Get back to [0,255] by dividing by maximum weight 16x16 = 256.
sum = _mm_srli_epi16(sum, 8);
- // Multiply by alpha.
- sum = _mm_mullo_epi16(sum, alpha);
+ if (s.fAlphaScale < 256) {
+ // Scale by alpha, which is in [0,256].
+ sum = _mm_mullo_epi16(sum, _mm_set1_epi16(s.fAlphaScale));
+ sum = _mm_srli_epi16(sum, 8);
+ }
- // Divide each 16 bit component by 256.
- sum = _mm_srli_epi16(sum, 8);
-
- // Pack lower 4 16 bit values of sum into lower 4 bytes.
- sum = _mm_packus_epi16(sum, zero);
-
- // Extract low int and store.
- *colors++ = _mm_cvtsi128_si32(sum);
- } while (--count > 0);
+ // Pack back into 8-bit values and store.
+ *colors++ = _mm_cvtsi128_si32(_mm_packus_epi16(sum, _mm_setzero_si128()));
+ }
}
#else
@@ -337,9 +289,11 @@
tmp = vmla_u16(tmp, vget_low_u16(tmp1), v16_x); // tmp += a00 * (16-x)
tmp = vmla_u16(tmp, vget_low_u16(tmp2), v16_x); // tmp += a10 * (16-x)
- vscale = vdup_n_u16(scale); // duplicate scale
- tmp = vshr_n_u16(tmp, 8); // shift down result by 8
- tmp = vmul_u16(tmp, vscale); // multiply result by scale
+ if (scale < 256) {
+ vscale = vdup_n_u16(scale); // duplicate scale
+ tmp = vshr_n_u16(tmp, 8); // shift down result by 8
+ tmp = vmul_u16(tmp, vscale); // multiply result by scale
+ }
vres = vshrn_n_u16(vcombine_u16(tmp, vcreate_u16(0)), 8); // shift down result by 8
vst1_lane_u32(dst, vreinterpret_u32_u8(vres), 0); // store result
@@ -372,17 +326,16 @@
lo += (a11 & mask) * xy;
hi += ((a11 >> 8) & mask) * xy;
- // TODO: if (alphaScale < 256) ...
- lo = ((lo >> 8) & mask) * alphaScale;
- hi = ((hi >> 8) & mask) * alphaScale;
+ if (alphaScale < 256) {
+ lo = ((lo >> 8) & mask) * alphaScale;
+ hi = ((hi >> 8) & mask) * alphaScale;
+ }
*dstColor = ((lo >> 8) & mask) | (hi & ~mask);
}
#endif
- // TODO(mtklein): clean up this code, use decode_packed_coordinates_and_weight(), etc.
-
/*not static*/ inline
void S32_alpha_D32_filter_DX(const SkBitmapProcState& s,
const uint32_t* xy, int count, SkPMColor* colors) {
@@ -391,38 +344,22 @@
SkASSERT(4 == s.fPixmap.info().bytesPerPixel());
SkASSERT(s.fAlphaScale <= 256);
- unsigned alphaScale = s.fAlphaScale;
+ int y0, y1, wy;
+ decode_packed_coordinates_and_weight(*xy++, &y0, &y1, &wy);
- const char* srcAddr = (const char*)s.fPixmap.addr();
- size_t rb = s.fPixmap.rowBytes();
- unsigned subY;
- const SkPMColor* row0;
- const SkPMColor* row1;
+ auto row0 = (const uint32_t*)( (const char*)s.fPixmap.addr() + y0 * s.fPixmap.rowBytes() ),
+ row1 = (const uint32_t*)( (const char*)s.fPixmap.addr() + y1 * s.fPixmap.rowBytes() );
- // setup row ptrs and update proc_table
- {
- uint32_t XY = *xy++;
- unsigned y0 = XY >> 14;
- row0 = (const SkPMColor*)(srcAddr + (y0 >> 4) * rb);
- row1 = (const SkPMColor*)(srcAddr + (XY & 0x3FFF) * rb);
- subY = y0 & 0xF;
- }
+ while (count --> 0) {
+ int x0, x1, wx;
+ decode_packed_coordinates_and_weight(*xy++, &x0, &x1, &wx);
- do {
- uint32_t XX = *xy++; // x0:14 | 4 | x1:14
- unsigned x0 = XX >> 14;
- unsigned x1 = XX & 0x3FFF;
- unsigned subX = x0 & 0xF;
- x0 >>= 4;
-
- filter_and_scale_by_alpha(subX, subY,
+ filter_and_scale_by_alpha(wx, wy,
row0[x0], row0[x1],
row1[x0], row1[x1],
- colors,
- alphaScale);
- colors += 1;
-
- } while (--count != 0);
+ colors++,
+ s.fAlphaScale);
+ }
}
#endif
