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author | mtklein <mtklein@chromium.org> | 2015-07-21 17:23:39 -0700 |
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committer | Commit bot <commit-bot@chromium.org> | 2015-07-21 17:23:39 -0700 |
commit | 860dcaa2ddfdadc050af4f943a84a9d499315066 (patch) | |
tree | 6265529dc51587c301017e2f9f54c059cd65629d /src/opts/Sk4px_SSE2.h | |
parent | c71239b9ff7d8c19dc03cb6c9081e7dc4e0947d2 (diff) |
565 support for SIMD xfermodes
This uses the most basic approach possible:
- to load an Sk4px from 565, convert to SkPMColors on the stack serially then load those SkPMColors.
- to store an Sk4px to 565, store to SkPMColors on the stack then convert to 565 serially.
Clearly, we can optimize these loads and stores. That's a TODO.
The code using SkPMFloat is the same idea but a little more long-term viable, as we're only operating on one pixel at a time anyway. We could probably write 565 <-> SkPMFloat methods, but I'd rather not until it's really compelling.
The speedups are varied but similar across SSE and NEON: a few uninteresting, many 50% faster, some 2x faster, and SoftLight ~4x faster.
This will cause minor GM diffs, but I don't think any layout test changes.
BUG=skia:
Committed: https://skia.googlesource.com/skia/+/942930dcaa51f66d82cdaf46ae62efebd16c8cd0
Review URL: https://codereview.chromium.org/1245673002
Diffstat (limited to 'src/opts/Sk4px_SSE2.h')
-rw-r--r-- | src/opts/Sk4px_SSE2.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/src/opts/Sk4px_SSE2.h b/src/opts/Sk4px_SSE2.h index 3809c5e47b..5e97abf308 100644 --- a/src/opts/Sk4px_SSE2.h +++ b/src/opts/Sk4px_SSE2.h @@ -93,4 +93,79 @@ inline Sk4px Sk4px::zeroAlphas() const { return Sk16b(_mm_andnot_si128(_mm_set1_epi32(0xFF << SK_A32_SHIFT), this->fVec)); } +static inline __m128i widen_low_half_to_8888(__m128i v) { + // RGB565 format: |R....|G.....|B....| + // Bit: 16 11 5 0 + + // First get each pixel into its own 32-bit lane. + // v == ____ ____ ____ ____ rgb3 rgb2 rgb1 rgb0 + // spread == 0000 rgb3 0000 rgb2 0000 rgb1 0000 rgb0 + auto spread = _mm_unpacklo_epi16(v, _mm_setzero_si128()); + + // Get each color independently, still in 565 precison but down at bit 0. + auto r5 = _mm_srli_epi32(spread, 11), + g6 = _mm_and_si128(_mm_set1_epi32(63), _mm_srli_epi32(spread, 5)), + b5 = _mm_and_si128(_mm_set1_epi32(31), spread); + + // Scale 565 precision up to 8-bit each, filling low 323 bits with high bits of each component. + auto r8 = _mm_or_si128(_mm_slli_epi32(r5, 3), _mm_srli_epi32(r5, 2)), + g8 = _mm_or_si128(_mm_slli_epi32(g6, 2), _mm_srli_epi32(g6, 4)), + b8 = _mm_or_si128(_mm_slli_epi32(b5, 3), _mm_srli_epi32(b5, 2)); + + // Now put all the 8-bit components into SkPMColor order. + return _mm_or_si128(_mm_slli_epi32(r8, SK_R32_SHIFT), // TODO: one of these shifts is zero... + _mm_or_si128(_mm_slli_epi32(g8, SK_G32_SHIFT), + _mm_or_si128(_mm_slli_epi32(b8, SK_B32_SHIFT), + _mm_set1_epi32(0xFF << SK_A32_SHIFT)))); +} + +static inline __m128i narrow_to_565(__m128i w) { + // Extract out top RGB 565 bits of each pixel, with no rounding. + auto r5 = _mm_and_si128(_mm_set1_epi32(31), _mm_srli_epi32(w, SK_R32_SHIFT + 3)), + g6 = _mm_and_si128(_mm_set1_epi32(63), _mm_srli_epi32(w, SK_G32_SHIFT + 2)), + b5 = _mm_and_si128(_mm_set1_epi32(31), _mm_srli_epi32(w, SK_B32_SHIFT + 3)); + + // Now put the bits in place in the low 16-bits of each 32-bit lane. + auto spread = _mm_or_si128(_mm_slli_epi32(r5, 11), + _mm_or_si128(_mm_slli_epi32(g6, 5), + b5)); + + // We want to pack the bottom 16-bits of spread down into the low half of the register, v. + // spread == 0000 rgb3 0000 rgb2 0000 rgb1 0000 rgb0 + // v == ____ ____ ____ ____ rgb3 rgb2 rgb1 rgb0 + + // Ideally now we'd use _mm_packus_epi32(spread, <anything>) to pack v. But that's from SSE4. + // With only SSE2, we need to use _mm_packs_epi32. That does signed saturation, and + // we need to preserve all 16 bits. So we pretend our data is signed by sign-extending first. + // TODO: is it faster to just _mm_shuffle_epi8 this when we have SSSE3? + auto signExtended = _mm_srai_epi32(_mm_slli_epi32(spread, 16), 16); + auto v = _mm_packs_epi32(signExtended, signExtended); + return v; +} + +inline Sk4px Sk4px::Load4(const SkPMColor16 src[4]) { + return Sk16b(widen_low_half_to_8888(_mm_loadl_epi64((const __m128i*)src))); +} +inline Sk4px Sk4px::Load2(const SkPMColor16 src[2]) { + auto src2 = ((uint32_t)src[0] ) + | ((uint32_t)src[1] << 16); + return Sk16b(widen_low_half_to_8888(_mm_cvtsi32_si128(src2))); +} +inline Sk4px Sk4px::Load1(const SkPMColor16 src[1]) { + return Sk16b(widen_low_half_to_8888(_mm_insert_epi16(_mm_setzero_si128(), src[0], 0))); +} + +inline void Sk4px::store4(SkPMColor16 dst[4]) const { + _mm_storel_epi64((__m128i*)dst, narrow_to_565(this->fVec)); +} +inline void Sk4px::store2(SkPMColor16 dst[2]) const { + uint32_t dst2 = _mm_cvtsi128_si32(narrow_to_565(this->fVec)); + dst[0] = dst2; + dst[1] = dst2 >> 16; +} +inline void Sk4px::store1(SkPMColor16 dst[1]) const { + uint32_t dst2 = _mm_cvtsi128_si32(narrow_to_565(this->fVec)); + dst[0] = dst2; +} + } // namespace |