1 /* 2 * Copyright 2015 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 namespace { // NOLINT(google-build-namespaces) 9 10 inline Sk4px::Wide Sk4px::widen() const { 11 return Sk16h(_mm_unpacklo_epi8(this->fVec, _mm_setzero_si128()), 12 _mm_unpackhi_epi8(this->fVec, _mm_setzero_si128())); 13 } 14 15 inline Sk4px::Wide Sk4px::mulWiden(const Sk16b& other) const { 16 return this->widen() * Sk4px(other).widen(); 17 } 18 19 inline Sk4px Sk4px::Wide::addNarrowHi(const Sk16h& other) const { 20 Sk4px::Wide r = (*this + other) >> 8; 21 return Sk4px(_mm_packus_epi16(r.fLo.fVec, r.fHi.fVec)); 22 } 23 24 inline Sk4px Sk4px::Wide::div255() const { 25 // (x + 127) / 255 == ((x+128) * 257)>>16, 26 // and _mm_mulhi_epu16 makes the (_ * 257)>>16 part very convenient. 27 const __m128i _128 = _mm_set1_epi16(128), 28 _257 = _mm_set1_epi16(257); 29 return Sk4px(_mm_packus_epi16(_mm_mulhi_epu16(_mm_add_epi16(fLo.fVec, _128), _257), 30 _mm_mulhi_epu16(_mm_add_epi16(fHi.fVec, _128), _257))); 31 } 32 33 // Load4Alphas and Load2Alphas use possibly-unaligned loads (SkAlpha[] -> uint16_t or uint32_t). 34 // These are safe on x86, often with no speed penalty. 35 36 #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSSE3 37 inline Sk4px Sk4px::alphas() const { 38 static_assert(SK_A32_SHIFT == 24, "Intel's always little-endian."); 39 __m128i splat = _mm_set_epi8(15,15,15,15, 11,11,11,11, 7,7,7,7, 3,3,3,3); 40 return Sk16b(_mm_shuffle_epi8(this->fVec, splat)); 41 } 42 43 inline Sk4px Sk4px::Load4Alphas(const SkAlpha a[4]) { 44 uint32_t as; 45 memcpy(&as, a, 4); 46 __m128i splat = _mm_set_epi8(3,3,3,3, 2,2,2,2, 1,1,1,1, 0,0,0,0); 47 return Sk16b(_mm_shuffle_epi8(_mm_cvtsi32_si128(as), splat)); 48 } 49 #else 50 inline Sk4px Sk4px::alphas() const { 51 static_assert(SK_A32_SHIFT == 24, "Intel's always little-endian."); 52 // We exploit that A >= rgb for any premul pixel. 53 __m128i as = fVec; // 3xxx 2xxx 1xxx 0xxx 54 as = _mm_max_epu8(as, _mm_srli_epi32(as, 8)); // 33xx 22xx 11xx 00xx 55 as = _mm_max_epu8(as, _mm_srli_epi32(as, 16)); // 3333 2222 1111 0000 56 return Sk16b(as); 57 } 58 59 inline Sk4px Sk4px::Load4Alphas(const SkAlpha a[4]) { 60 __m128i as; 61 memcpy(&as, a, 4); // ____ ____ ____ 3210 62 as = _mm_unpacklo_epi8 (as, as); // ____ ____ 3322 1100 63 as = _mm_unpacklo_epi16(as, as); // 3333 2222 1111 0000 64 return Sk16b(as); 65 } 66 #endif 67 68 inline Sk4px Sk4px::Load2Alphas(const SkAlpha a[2]) { 69 uint16_t alphas; 70 memcpy(&alphas, a, 2); 71 uint32_t alphas_and_two_zeros = alphas; // Aa -> Aa00 72 73 return Load4Alphas((const SkAlpha*)&alphas_and_two_zeros); 74 } 75 76 } // namespace 77