blob: d2f8882726c204325c3dc5eb3a71581e3904c461 [file] [log] [blame]
/*
* Copyright 2013 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <emmintrin.h>
#include "SkBitmap.h"
#include "SkBlurImage_opts_SSE2.h"
#include "SkColorPriv.h"
#include "SkRect.h"
namespace {
enum BlurDirection {
kX, kY
};
/* Helper function to spread the components of a 32-bit integer into the
* lower 8 bits of each 32-bit element of an SSE register.
*/
inline __m128i expand(int a) {
const __m128i zero = _mm_setzero_si128();
// 0 0 0 0 0 0 0 0 0 0 0 0 A R G B
__m128i result = _mm_cvtsi32_si128(a);
// 0 0 0 0 0 0 0 0 0 A 0 R 0 G 0 B
result = _mm_unpacklo_epi8(result, zero);
// 0 0 0 A 0 0 0 R 0 0 0 G 0 0 0 B
return _mm_unpacklo_epi16(result, zero);
}
template<BlurDirection srcDirection, BlurDirection dstDirection>
void SkBoxBlur_SSE2(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize,
int leftOffset, int rightOffset, int width, int height)
{
const int rightBorder = SkMin32(rightOffset + 1, width);
const int srcStrideX = srcDirection == kX ? 1 : srcStride;
const int dstStrideX = dstDirection == kX ? 1 : height;
const int srcStrideY = srcDirection == kX ? srcStride : 1;
const int dstStrideY = dstDirection == kX ? width : 1;
const __m128i scale = _mm_set1_epi32((1 << 24) / kernelSize);
const __m128i half = _mm_set1_epi32(1 << 23);
const __m128i zero = _mm_setzero_si128();
for (int y = 0; y < height; ++y) {
__m128i sum = zero;
const SkPMColor* p = src;
for (int i = 0; i < rightBorder; ++i) {
sum = _mm_add_epi32(sum, expand(*p));
p += srcStrideX;
}
const SkPMColor* sptr = src;
SkColor* dptr = dst;
for (int x = 0; x < width; ++x) {
// SSE2 has no PMULLUD, so we must do AG and RB separately.
__m128i tmp1 = _mm_mul_epu32(sum, scale);
__m128i tmp2 = _mm_mul_epu32(_mm_srli_si128(sum, 4),
_mm_srli_si128(scale, 4));
__m128i result = _mm_unpacklo_epi32(_mm_shuffle_epi32(tmp1, _MM_SHUFFLE(0,0,2,0)),
_mm_shuffle_epi32(tmp2, _MM_SHUFFLE(0,0,2,0)));
// sumA*scale+.5 sumB*scale+.5 sumG*scale+.5 sumB*scale+.5
result = _mm_add_epi32(result, half);
// 0 0 0 A 0 0 0 R 0 0 0 G 0 0 0 B
result = _mm_srli_epi32(result, 24);
// 0 0 0 0 0 0 0 0 0 A 0 R 0 G 0 B
result = _mm_packs_epi32(result, zero);
// 0 0 0 0 0 0 0 0 0 0 0 0 A R G B
result = _mm_packus_epi16(result, zero);
*dptr = _mm_cvtsi128_si32(result);
if (x >= leftOffset) {
SkColor l = *(sptr - leftOffset * srcStrideX);
sum = _mm_sub_epi32(sum, expand(l));
}
if (x + rightOffset + 1 < width) {
SkColor r = *(sptr + (rightOffset + 1) * srcStrideX);
sum = _mm_add_epi32(sum, expand(r));
}
sptr += srcStrideX;
if (srcDirection == kY) {
_mm_prefetch(reinterpret_cast<const char*>(sptr + (rightOffset + 1) * srcStrideX),
_MM_HINT_T0);
}
dptr += dstStrideX;
}
src += srcStrideY;
dst += dstStrideY;
}
}
} // namespace
bool SkBoxBlurGetPlatformProcs_SSE2(SkBoxBlurProc* boxBlurX,
SkBoxBlurProc* boxBlurY,
SkBoxBlurProc* boxBlurXY,
SkBoxBlurProc* boxBlurYX) {
*boxBlurX = SkBoxBlur_SSE2<kX, kX>;
*boxBlurY = SkBoxBlur_SSE2<kY, kY>;
*boxBlurXY = SkBoxBlur_SSE2<kX, kY>;
*boxBlurYX = SkBoxBlur_SSE2<kY, kX>;
return true;
}