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SSE2: 53% faster TransformColor[Inverse]

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Changed the code (again) to process 4 pixels at a time. Loop is more
involved, but overall it's faster.

Removed the SSE4.1 implementation which is now slower than SSE2.

Change-Id: I7734e371033ad8929ace7f7e1373ba930d9bb5f1
This commit is contained in:
Pascal Massimino
2015-06-23 21:37:18 +02:00
parent 49073da6d6
commit fc6c75a2a2
3 changed files with 39 additions and 73 deletions
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44
src/dsp/lossless_enc_sse2.c
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@ -41,30 +41,34 @@ static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixels) {
// Color Transform
static WEBP_INLINE void TransformColor(const VP8LMultipliers* const m,
uint32_t* argb_data,
int num_pixels) {
// Used to collect the two parts of the delta (horizontal add) with madd.
const __m128i kCstAdd = _mm_set1_epi16(1);
uint32_t* argb_data, int num_pixels) {
// sign-extended multiplying constants, pre-shifted by 5.
#define CST(X) (((int16_t)(m->X << 8)) >> 5) // sign-extend
const __m128i mults = _mm_set_epi16(
CST(green_to_red_), 0, CST(red_to_blue_), CST(green_to_blue_),
CST(green_to_red_), 0, CST(red_to_blue_), CST(green_to_blue_));
const __m128i mults_rb = _mm_set_epi16(
CST(green_to_red_), CST(green_to_blue_),
CST(green_to_red_), CST(green_to_blue_),
CST(green_to_red_), CST(green_to_blue_),
CST(green_to_red_), CST(green_to_blue_));
const __m128i mults_b2 = _mm_set_epi16(
CST(red_to_blue_), 0, CST(red_to_blue_), 0,
CST(red_to_blue_), 0, CST(red_to_blue_), 0);
#undef CST
const __m128i zero = _mm_setzero_si128();
const __m128i mask = _mm_set1_epi32(0xff);
const __m128i mask_ag = _mm_set1_epi32(0xff00ff00); // alpha-green masks
const __m128i mask_rb = _mm_set1_epi32(0x00ff00ff); // red-blue masks
int i;
for (i = 0; i + 2 <= num_pixels; i += 2) {
const __m128i in = _mm_loadl_epi64((__m128i*)&argb_data[i]); // argb
const __m128i A = _mm_unpacklo_epi8(zero, in);
const __m128i B = _mm_shufflelo_epi16(A, _MM_SHUFFLE(1, 0, 2, 1)); // gxrg
const __m128i C = _mm_shufflehi_epi16(B, _MM_SHUFFLE(1, 0, 2, 1));
const __m128i D = _mm_mulhi_epi16(C, mults); // dr | 0 | db1 | db2
const __m128i E = _mm_madd_epi16(D, kCstAdd); // 0 | dr | 0 | db
const __m128i F = _mm_and_si128(E, mask);
const __m128i G = _mm_packus_epi16(F, zero); // dr | 0 | db | 0
const __m128i out = _mm_sub_epi8(in, G);
_mm_storel_epi64((__m128i*)&argb_data[i], out);
for (i = 0; i + 4 <= num_pixels; i += 4) {
const __m128i in = _mm_loadu_si128((__m128i*)&argb_data[i]); // argb
const __m128i A = _mm_and_si128(in, mask_ag); // a 0 g 0
const __m128i B = _mm_shufflelo_epi16(A, _MM_SHUFFLE(2, 2, 0, 0));
const __m128i C = _mm_shufflehi_epi16(B, _MM_SHUFFLE(2, 2, 0, 0)); // g0g0
const __m128i D = _mm_mulhi_epi16(C, mults_rb); // x dr x db1
const __m128i E = _mm_slli_epi16(in, 8); // r 0 b 0
const __m128i F = _mm_mulhi_epi16(E, mults_b2); // x db2 0 0
const __m128i G = _mm_srli_epi32(F, 16); // 0 0 x db2
const __m128i H = _mm_add_epi8(G, D); // x dr x db
const __m128i I = _mm_and_si128(H, mask_rb); // 0 dr 0 db
const __m128i out = _mm_sub_epi8(in, I);
_mm_storeu_si128((__m128i*)&argb_data[i], out);
}
// fallthrough and finish off with plain-C
VP8LTransformColor_C(m, argb_data + i, num_pixels - i);