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// For SkPMFloat(SkPMColor), we widen our 8 bit components (fix8) to 8-bit components in 16 bits 9// (fix8_16), then widen those to 8-bit-in-32-bits (fix8_32), and finally convert those to floats. 10 11// round() and roundClamp() do the opposite, working from floats to 8-bit-in-32-bit, 12// to 8-bit-in-16-bit, back down to 8-bit components. 13// _mm_packus_epi16() gives us clamping for free while narrowing. 14 15inline SkPMFloat::SkPMFloat(SkPMColor c) { 16 SkPMColorAssert(c); 17 __m128i fix8 = _mm_set_epi32(0,0,0,c), 18 fix8_16 = _mm_unpacklo_epi8 (fix8, _mm_setzero_si128()), 19 fix8_32 = _mm_unpacklo_epi16(fix8_16, _mm_setzero_si128()); 20 fVec = _mm_cvtepi32_ps(fix8_32); 21 SkASSERT(this->isValid()); 22} 23 24inline SkPMColor SkPMFloat::round() const { 25 return this->roundClamp(); // Haven't beaten this yet. 26} 27 28inline SkPMColor SkPMFloat::roundClamp() const { 29 // We don't use _mm_cvtps_epi32, because we want precise control over how 0.5 rounds (up). 30 __m128i fix8_32 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), fVec)), 31 fix8_16 = _mm_packus_epi16(fix8_32, fix8_32), 32 fix8 = _mm_packus_epi16(fix8_16, fix8_16); 33 SkPMColor c = _mm_cvtsi128_si32(fix8); 34 SkPMColorAssert(c); 35 return c; 36} 37 38inline SkPMColor SkPMFloat::trunc() const { 39 // Basically, same as roundClamp(), but no rounding. 40 __m128i fix8_32 = _mm_cvttps_epi32(fVec), 41 fix8_16 = _mm_packus_epi16(fix8_32, fix8_32), 42 fix8 = _mm_packus_epi16(fix8_16, fix8_16); 43 SkPMColor c = _mm_cvtsi128_si32(fix8); 44 SkPMColorAssert(c); 45 return c; 46} 47 48inline void SkPMFloat::From4PMColors(const SkPMColor colors[4], 49 SkPMFloat* a, SkPMFloat* b, SkPMFloat* c, SkPMFloat* d) { 50 // Haven't beaten this yet. 51 *a = FromPMColor(colors[0]); 52 *b = FromPMColor(colors[1]); 53 *c = FromPMColor(colors[2]); 54 *d = FromPMColor(colors[3]); 55} 56 57inline void SkPMFloat::RoundTo4PMColors( 58 const SkPMFloat& a, const SkPMFloat& b, const SkPMFloat&c, const SkPMFloat& d, 59 SkPMColor colors[4]) { 60 // Haven't beaten this yet. 61 RoundClampTo4PMColors(a,b,c,d, colors); 62} 63 64inline void SkPMFloat::RoundClampTo4PMColors( 65 const SkPMFloat& a, const SkPMFloat& b, const SkPMFloat&c, const SkPMFloat& d, 66 SkPMColor colors[4]) { 67 // Same as _SSSE3.h's. We use 3 _mm_packus_epi16() where the naive loop uses 8. 68 // We don't use _mm_cvtps_epi32, because we want precise control over how 0.5 rounds (up). 69 __m128i c0 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), a.fVec)), 70 c1 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), b.fVec)), 71 c2 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), c.fVec)), 72 c3 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), d.fVec)); 73 __m128i c3210 = _mm_packus_epi16(_mm_packus_epi16(c0, c1), 74 _mm_packus_epi16(c2, c3)); 75 _mm_storeu_si128((__m128i*)colors, c3210); 76 SkPMColorAssert(colors[0]); 77 SkPMColorAssert(colors[1]); 78 SkPMColorAssert(colors[2]); 79 SkPMColorAssert(colors[3]); 80} 81