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4-5% faster encoding using SSE2 for GetResidualCost

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new file: cost_sse2.c

Change-Id: I4896c07f5ff2443ef743f4435fe2758d95a672ed
This commit is contained in:
Pascal Massimino
2015-02-18 09:40:30 +01:00
parent 17e1986214
commit 2a407092ab
7 changed files with 127 additions and 34 deletions
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28
src/dsp/enc_sse2.c
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@ -914,33 +914,6 @@ static int Quantize2Blocks(int16_t in[32], int16_t out[32],
return nz;
}
// Forward declaration.
void VP8SetResidualCoeffsSSE2(const int16_t* const coeffs,
VP8Residual* const res);
void VP8SetResidualCoeffsSSE2(const int16_t* const coeffs,
VP8Residual* const res) {
const __m128i c0 = _mm_loadu_si128((const __m128i*)coeffs);
const __m128i c1 = _mm_loadu_si128((const __m128i*)(coeffs + 8));
// Use SSE to compare 8 values with a single instruction.
const __m128i zero = _mm_setzero_si128();
const __m128i m0 = _mm_cmpeq_epi16(c0, zero);
const __m128i m1 = _mm_cmpeq_epi16(c1, zero);
// Get the comparison results as a bitmask, consisting of two times 16 bits:
// two identical bits for each result. Concatenate both bitmasks to get a
// single 32 bit value. Negate the mask to get the position of entries that
// are not equal to zero. We don't need to mask out least significant bits
// according to res->first, since coeffs[0] is 0 if res->first > 0
const uint32_t mask =
~(((uint32_t)_mm_movemask_epi8(m1) << 16) | _mm_movemask_epi8(m0));
// The position of the most significant non-zero bit indicates the position of
// the last non-zero value. Divide the result by two because __movemask_epi8
// operates on 8 bit values instead of 16 bit values.
assert(res->first == 0 || coeffs[0] == 0);
res->last = mask ? (BitsLog2Floor(mask) >> 1) : -1;
res->coeffs = coeffs;
}
#endif // WEBP_USE_SSE2
//------------------------------------------------------------------------------
@ -965,4 +938,3 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspInitSSE2(void) {
VP8TDisto16x16 = Disto16x16;
#endif // WEBP_USE_SSE2
}