/*
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* Copyright 2015 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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namespace { // NOLINT(google-build-namespaces)
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inline Sk4px::Wide Sk4px::widen() const {
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return Sk16h(_mm_unpacklo_epi8(this->fVec, _mm_setzero_si128()),
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_mm_unpackhi_epi8(this->fVec, _mm_setzero_si128()));
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}
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inline Sk4px::Wide Sk4px::mulWiden(const Sk16b& other) const {
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return this->widen() * Sk4px(other).widen();
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}
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inline Sk4px Sk4px::Wide::addNarrowHi(const Sk16h& other) const {
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Sk4px::Wide r = (*this + other) >> 8;
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return Sk4px(_mm_packus_epi16(r.fLo.fVec, r.fHi.fVec));
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}
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inline Sk4px Sk4px::Wide::div255() const {
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// (x + 127) / 255 == ((x+128) * 257)>>16,
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// and _mm_mulhi_epu16 makes the (_ * 257)>>16 part very convenient.
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const __m128i _128 = _mm_set1_epi16(128),
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_257 = _mm_set1_epi16(257);
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return Sk4px(_mm_packus_epi16(_mm_mulhi_epu16(_mm_add_epi16(fLo.fVec, _128), _257),
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_mm_mulhi_epu16(_mm_add_epi16(fHi.fVec, _128), _257)));
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}
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// Load4Alphas and Load2Alphas use possibly-unaligned loads (SkAlpha[] -> uint16_t or uint32_t).
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// These are safe on x86, often with no speed penalty.
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#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSSE3
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inline Sk4px Sk4px::alphas() const {
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static_assert(SK_A32_SHIFT == 24, "Intel's always little-endian.");
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__m128i splat = _mm_set_epi8(15,15,15,15, 11,11,11,11, 7,7,7,7, 3,3,3,3);
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return Sk16b(_mm_shuffle_epi8(this->fVec, splat));
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}
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inline Sk4px Sk4px::Load4Alphas(const SkAlpha a[4]) {
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uint32_t as;
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memcpy(&as, a, 4);
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__m128i splat = _mm_set_epi8(3,3,3,3, 2,2,2,2, 1,1,1,1, 0,0,0,0);
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return Sk16b(_mm_shuffle_epi8(_mm_cvtsi32_si128(as), splat));
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}
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#else
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inline Sk4px Sk4px::alphas() const {
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static_assert(SK_A32_SHIFT == 24, "Intel's always little-endian.");
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// We exploit that A >= rgb for any premul pixel.
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__m128i as = fVec; // 3xxx 2xxx 1xxx 0xxx
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as = _mm_max_epu8(as, _mm_srli_epi32(as, 8)); // 33xx 22xx 11xx 00xx
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as = _mm_max_epu8(as, _mm_srli_epi32(as, 16)); // 3333 2222 1111 0000
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return Sk16b(as);
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}
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inline Sk4px Sk4px::Load4Alphas(const SkAlpha a[4]) {
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__m128i as;
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memcpy(&as, a, 4); // ____ ____ ____ 3210
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as = _mm_unpacklo_epi8 (as, as); // ____ ____ 3322 1100
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as = _mm_unpacklo_epi16(as, as); // 3333 2222 1111 0000
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return Sk16b(as);
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}
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#endif
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inline Sk4px Sk4px::Load2Alphas(const SkAlpha a[2]) {
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uint16_t alphas;
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memcpy(&alphas, a, 2);
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uint32_t alphas_and_two_zeros = alphas; // Aa -> Aa00
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return Load4Alphas((const SkAlpha*)&alphas_and_two_zeros);
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}
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} // namespace
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