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SIMD Convert. RGBa → RGBA convert using gather

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homm 2016-05-29 23:30:38 +03:00 committed by Alexander Karpinsky
parent 55b71f2edb
commit f888dbe1cc
1 changed files with 54 additions and 3 deletions
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57
src/libImaging/Convert.c
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@ -541,13 +541,64 @@ rgbA2rgba(UINT8* out, const UINT8* in, int xsize)
}
}
int *rgba2rgbAtable = NULL;
/* RGBa -> RGBA conversion to remove premultiplication
Needed for correct transforms/resizing on RGBA images */
static void
rgba2rgbA(UINT8 *out, const UINT8 *in, int xsize) {
int x;
rgba2rgbA(UINT8* out, const UINT8* in, int xsize)
{
int x = 0;
unsigned int alpha;
for (x = 0; x < xsize; x++, in += 4) {
#if defined(__AVX2__)
int a, c;
if ( ! rgba2rgbAtable) {
rgba2rgbAtable = (int *) malloc(256 * 256 * 2 * 4);
for (c = 0; c < 256; c++) {
rgba2rgbAtable[c] = c;
}
for (a = 1; a < 256; a++) {
for (c = 0; c < 256; c++) {
rgba2rgbAtable[a * 256 + c] = CLIP((255 * c) / a);
}
}
}
for (; x < xsize - 7; x += 8) {
__m256i pix0, pix1, pix2, pix3;
__m256i source = _mm256_loadu_si256((__m256i *) &in[x * 4]);
pix0 = _mm256_shuffle_epi8(source, _mm256_set_epi8(
-1,-1,-1,3, -1,-1,3,2, -1,-1,3,1, -1,-1,3,0,
-1,-1,-1,3, -1,-1,3,2, -1,-1,3,1, -1,-1,3,0));
pix0 = _mm256_i32gather_epi32(rgba2rgbAtable, pix0, 4);
pix1 = _mm256_shuffle_epi8(source, _mm256_set_epi8(
-1,-1,-1,7, -1,-1,7,6, -1,-1,7,5, -1,-1,7,4,
-1,-1,-1,7, -1,-1,7,6, -1,-1,7,5, -1,-1,7,4));
pix1 = _mm256_i32gather_epi32(rgba2rgbAtable, pix1, 4);
pix2 = _mm256_shuffle_epi8(source, _mm256_set_epi8(
-1,-1,-1,11, -1,-1,11,10, -1,-1,11,9, -1,-1,11,8,
-1,-1,-1,11, -1,-1,11,10, -1,-1,11,9, -1,-1,11,8));
pix2 = _mm256_i32gather_epi32(rgba2rgbAtable, pix2, 4);
pix3 = _mm256_shuffle_epi8(source, _mm256_set_epi8(
-1,-1,-1,15, -1,-1,15,14, -1,-1,15,13, -1,-1,15,12,
-1,-1,-1,15, -1,-1,15,14, -1,-1,15,13, -1,-1,15,12));
pix3 = _mm256_i32gather_epi32(rgba2rgbAtable, pix3, 4);
pix0 = _mm256_packus_epi32(pix0, pix1);
pix2 = _mm256_packus_epi32(pix2, pix3);
source = _mm256_packus_epi16(pix0, pix2);
_mm256_storeu_si256((__m256i *) &out[x * 4], source);
}
#endif
for (; x < xsize; x++, in+=4) {
alpha = in[3];
if (alpha == 255 || alpha == 0) {
*out++ = in[0];