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Merge "wasm: cleanup _pack_sw_2_sb(), SignedShift8b()" into portable-intrinsics

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Scott LaVarnway 2017-07-11 19:27:57 +00:00 committed by Gerrit Code Review
commit 599bddb658
1 changed files with 6 additions and 22 deletions
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28
src/dsp/dec_wasm.c
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@ -423,34 +423,18 @@ static WEBP_INLINE int8x16 abs_diff(int8x16 p, int8x16 q) {
}
// int16 to int8 with saturation.
static inline int8x16 _pack_sw_2_sb(const int16x8 lo, const int16x8 hi) {
#if 1
const int16x8 k7f = splat_int16(0x007f);
const int16x8 kff80 = splat_int16(0xff80);
const int16x8 s1_lo = (lo < k7f);
const int16x8 a_lo = (s1_lo & lo) | (~s1_lo & k7f);
const int16x8 s2_lo = (a_lo > kff80);
const int16x8 a2_lo = (s2_lo & a_lo) | (~s2_lo & kff80);
const int16x8 s1_hi = (hi < k7f);
const int16x8 a_hi = (s1_hi & hi) | (~s1_hi & k7f);
const int16x8 s2_hi = (a_hi > kff80);
const int16x8 a2_hi = (s2_hi & a_hi) | (~s2_hi & kff80);
return (int8x16)__builtin_shufflevector((int8x16)a2_lo, (int8x16)a2_hi, 0, 2,
4, 6, 8, 10, 12, 14, 16, 18, 20, 22,
24, 26, 28, 30);
#else
return (int8x16)__builtin_ia32_packsswb128(lo, hi);
#endif
static WEBP_INLINE int8x16 _pack_sw_2_sb(const int16x8 lo, const int16x8 hi) {
const int8x16 sat_lo = int16x8_to_int8x16_sat(lo);
const int8x16 sat_hi = int16x8_to_int8x16_sat(hi);
return _unpacklo_epi64(sat_lo, sat_hi);
}
// Shift each byte of "x" by 3 bits while preserving by the sign bit.
static WEBP_INLINE void SignedShift8b(int8x16* const x) {
const int8x16 zero = {0};
const int16x8 eleven = splat_int16(3 + 8);
const int16x8 lo_0 = (int16x8)__builtin_shufflevector(
*x, zero, 16, 0, 16, 1, 16, 2, 16, 3, 16, 4, 16, 5, 16, 6, 16, 7);
const int16x8 hi_0 = (int16x8)__builtin_shufflevector(
*x, zero, 16, 8, 16, 9, 16, 10, 16, 11, 16, 12, 16, 13, 16, 14, 16, 15);
const int16x8 lo_0 = _unpacklo_epi8(zero, *x);
const int16x8 hi_0 = _unpackhi_epi8(zero, *x);
const int16x8 lo_1 = lo_0 >> eleven;
const int16x8 hi_1 = hi_0 >> eleven;
*x = _pack_sw_2_sb(lo_1, hi_1);