BlurSSE2.cpp
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "Blur.h"
#include "SSEHelpers.h"
#include <string.h>
namespace mozilla {
namespace gfx {
MOZ_ALWAYS_INLINE
__m128i Divide(__m128i aValues, __m128i aDivisor)
{
const __m128i mask = _mm_setr_epi32(0x0, 0xffffffff, 0x0, 0xffffffff);
static const union {
int64_t i64[2];
__m128i m;
} roundingAddition = { { int64_t(1) << 31, int64_t(1) << 31 } };
__m128i multiplied31 = _mm_mul_epu32(aValues, aDivisor);
__m128i multiplied42 = _mm_mul_epu32(_mm_srli_epi64(aValues, 32), aDivisor);
// Add 1 << 31 before shifting or masking the lower 32 bits away, so that the
// result is rounded.
__m128i p_3_1 = _mm_srli_epi64(_mm_add_epi64(multiplied31, roundingAddition.m), 32);
__m128i p4_2_ = _mm_and_si128(_mm_add_epi64(multiplied42, roundingAddition.m), mask);
__m128i p4321 = _mm_or_si128(p_3_1, p4_2_);
return p4321;
}
MOZ_ALWAYS_INLINE
__m128i BlurFourPixels(const __m128i& aTopLeft, const __m128i& aTopRight,
const __m128i& aBottomRight, const __m128i& aBottomLeft,
const __m128i& aDivisor)
{
__m128i values = _mm_add_epi32(_mm_sub_epi32(_mm_sub_epi32(aBottomRight, aTopRight), aBottomLeft), aTopLeft);
return Divide(values, aDivisor);
}
MOZ_ALWAYS_INLINE
void LoadIntegralRowFromRow(uint32_t *aDest, const uint8_t *aSource,
int32_t aSourceWidth, int32_t aLeftInflation,
int32_t aRightInflation)
{
int32_t currentRowSum = 0;
for (int x = 0; x < aLeftInflation; x++) {
currentRowSum += aSource[0];
aDest[x] = currentRowSum;
}
for (int x = aLeftInflation; x < (aSourceWidth + aLeftInflation); x++) {
currentRowSum += aSource[(x - aLeftInflation)];
aDest[x] = currentRowSum;
}
for (int x = (aSourceWidth + aLeftInflation); x < (aSourceWidth + aLeftInflation + aRightInflation); x++) {
currentRowSum += aSource[aSourceWidth - 1];
aDest[x] = currentRowSum;
}
}
// This function calculates an integral of four pixels stored in the 4
// 32-bit integers on aPixels. i.e. for { 30, 50, 80, 100 } this returns
// { 30, 80, 160, 260 }. This seems to be the fastest way to do this after
// much testing.
MOZ_ALWAYS_INLINE
__m128i AccumulatePixelSums(__m128i aPixels)
{
__m128i sumPixels = aPixels;
__m128i currentPixels = _mm_slli_si128(aPixels, 4);
sumPixels = _mm_add_epi32(sumPixels, currentPixels);
currentPixels = _mm_unpacklo_epi64(_mm_setzero_si128(), sumPixels);
return _mm_add_epi32(sumPixels, currentPixels);
}
MOZ_ALWAYS_INLINE void
GenerateIntegralImage_SSE2(int32_t aLeftInflation, int32_t aRightInflation,
int32_t aTopInflation, int32_t aBottomInflation,
uint32_t *aIntegralImage, size_t aIntegralImageStride,
uint8_t *aSource, int32_t aSourceStride, const IntSize &aSize)
{
MOZ_ASSERT(!(aLeftInflation & 3));
uint32_t stride32bit = aIntegralImageStride / 4;
IntSize integralImageSize(aSize.width + aLeftInflation + aRightInflation,
aSize.height + aTopInflation + aBottomInflation);
LoadIntegralRowFromRow(aIntegralImage, aSource, aSize.width, aLeftInflation, aRightInflation);
for (int y = 1; y < aTopInflation + 1; y++) {
uint32_t *intRow = aIntegralImage + (y * stride32bit);
uint32_t *intPrevRow = aIntegralImage + (y - 1) * stride32bit;
uint32_t *intFirstRow = aIntegralImage;
for (int x = 0; x < integralImageSize.width; x += 4) {
__m128i firstRow = _mm_load_si128((__m128i*)(intFirstRow + x));
__m128i previousRow = _mm_load_si128((__m128i*)(intPrevRow + x));
_mm_store_si128((__m128i*)(intRow + x), _mm_add_epi32(firstRow, previousRow));
}
}
for (int y = aTopInflation + 1; y < (aSize.height + aTopInflation); y++) {
__m128i currentRowSum = _mm_setzero_si128();
uint32_t *intRow = aIntegralImage + (y * stride32bit);
uint32_t *intPrevRow = aIntegralImage + (y - 1) * stride32bit;
uint8_t *sourceRow = aSource + aSourceStride * (y - aTopInflation);
uint32_t pixel = sourceRow[0];
for (int x = 0; x < aLeftInflation; x += 4) {
__m128i sumPixels = AccumulatePixelSums(_mm_shuffle_epi32(_mm_set1_epi32(pixel), _MM_SHUFFLE(0, 0, 0, 0)));
sumPixels = _mm_add_epi32(sumPixels, currentRowSum);
currentRowSum = _mm_shuffle_epi32(sumPixels, _MM_SHUFFLE(3, 3, 3, 3));
_mm_store_si128((__m128i*)(intRow + x), _mm_add_epi32(sumPixels, _mm_load_si128((__m128i*)(intPrevRow + x))));
}
for (int x = aLeftInflation; x < (aSize.width + aLeftInflation); x += 4) {
uint32_t pixels = *(uint32_t*)(sourceRow + (x - aLeftInflation));
// It's important to shuffle here. When we exit this loop currentRowSum
// has to be set to sumPixels, so that the following loop can get the
// correct pixel for the currentRowSum. The highest order pixel in
// currentRowSum could've originated from accumulation in the stride.
currentRowSum = _mm_shuffle_epi32(currentRowSum, _MM_SHUFFLE(3, 3, 3, 3));
__m128i sumPixels = AccumulatePixelSums(_mm_unpacklo_epi16(_mm_unpacklo_epi8( _mm_set1_epi32(pixels), _mm_setzero_si128()), _mm_setzero_si128()));
sumPixels = _mm_add_epi32(sumPixels, currentRowSum);
currentRowSum = sumPixels;
_mm_store_si128((__m128i*)(intRow + x), _mm_add_epi32(sumPixels, _mm_load_si128((__m128i*)(intPrevRow + x))));
}
pixel = sourceRow[aSize.width - 1];
int x = (aSize.width + aLeftInflation);
if ((aSize.width & 3)) {
// Deal with unaligned portion. Get the correct pixel from currentRowSum,
// see explanation above.
uint32_t intCurrentRowSum = ((uint32_t*)¤tRowSum)[(aSize.width % 4) - 1];
for (; x < integralImageSize.width; x++) {
// We could be unaligned here!
if (!(x & 3)) {
// aligned!
currentRowSum = _mm_set1_epi32(intCurrentRowSum);
break;
}
intCurrentRowSum += pixel;
intRow[x] = intPrevRow[x] + intCurrentRowSum;
}
} else {
currentRowSum = _mm_shuffle_epi32(currentRowSum, _MM_SHUFFLE(3, 3, 3, 3));
}
for (; x < integralImageSize.width; x += 4) {
__m128i sumPixels = AccumulatePixelSums(_mm_set1_epi32(pixel));
sumPixels = _mm_add_epi32(sumPixels, currentRowSum);
currentRowSum = _mm_shuffle_epi32(sumPixels, _MM_SHUFFLE(3, 3, 3, 3));
_mm_store_si128((__m128i*)(intRow + x), _mm_add_epi32(sumPixels, _mm_load_si128((__m128i*)(intPrevRow + x))));
}
}
if (aBottomInflation) {
// Store the last valid row of our source image in the last row of
// our integral image. This will be overwritten with the correct values
// in the upcoming loop.
LoadIntegralRowFromRow(aIntegralImage + (integralImageSize.height - 1) * stride32bit,
aSource + (aSize.height - 1) * aSourceStride, aSize.width, aLeftInflation, aRightInflation);
for (int y = aSize.height + aTopInflation; y < integralImageSize.height; y++) {
__m128i *intRow = (__m128i*)(aIntegralImage + (y * stride32bit));
__m128i *intPrevRow = (__m128i*)(aIntegralImage + (y - 1) * stride32bit);
__m128i *intLastRow = (__m128i*)(aIntegralImage + (integralImageSize.height - 1) * stride32bit);
for (int x = 0; x < integralImageSize.width; x += 4) {
_mm_store_si128(intRow + (x / 4),
_mm_add_epi32(_mm_load_si128(intLastRow + (x / 4)),
_mm_load_si128(intPrevRow + (x / 4))));
}
}
}
}
/**
* Attempt to do an in-place box blur using an integral image.
*/
void
AlphaBoxBlur::BoxBlur_SSE2(uint8_t* aData,
int32_t aLeftLobe,
int32_t aRightLobe,
int32_t aTopLobe,
int32_t aBottomLobe,
uint32_t *aIntegralImage,
size_t aIntegralImageStride)
{
IntSize size = GetSize();
MOZ_ASSERT(size.height > 0);
// Our 'left' or 'top' lobe will include the current pixel. i.e. when
// looking at an integral image the value of a pixel at 'x,y' is calculated
// using the value of the integral image values above/below that.
aLeftLobe++;
aTopLobe++;
int32_t boxSize = (aLeftLobe + aRightLobe) * (aTopLobe + aBottomLobe);
MOZ_ASSERT(boxSize > 0);
if (boxSize == 1) {
return;
}
uint32_t reciprocal = uint32_t((uint64_t(1) << 32) / boxSize);
uint32_t stride32bit = aIntegralImageStride / 4;
int32_t leftInflation = RoundUpToMultipleOf4(aLeftLobe).value();
GenerateIntegralImage_SSE2(leftInflation, aRightLobe, aTopLobe, aBottomLobe,
aIntegralImage, aIntegralImageStride, aData,
mStride, size);
__m128i divisor = _mm_set1_epi32(reciprocal);
// This points to the start of the rectangle within the IntegralImage that overlaps
// the surface being blurred.
uint32_t *innerIntegral = aIntegralImage + (aTopLobe * stride32bit) + leftInflation;
IntRect skipRect = mSkipRect;
int32_t stride = mStride;
uint8_t *data = aData;
for (int32_t y = 0; y < size.height; y++) {
bool inSkipRectY = y > skipRect.y && y < skipRect.YMost();
uint32_t *topLeftBase = innerIntegral + ((y - aTopLobe) * ptrdiff_t(stride32bit) - aLeftLobe);
uint32_t *topRightBase = innerIntegral + ((y - aTopLobe) * ptrdiff_t(stride32bit) + aRightLobe);
uint32_t *bottomRightBase = innerIntegral + ((y + aBottomLobe) * ptrdiff_t(stride32bit) + aRightLobe);
uint32_t *bottomLeftBase = innerIntegral + ((y + aBottomLobe) * ptrdiff_t(stride32bit) - aLeftLobe);
int32_t x = 0;
// Process 16 pixels at a time for as long as possible.
for (; x <= size.width - 16; x += 16) {
if (inSkipRectY && x > skipRect.x && x < skipRect.XMost()) {
x = skipRect.XMost() - 16;
// Trigger early jump on coming loop iterations, this will be reset
// next line anyway.
inSkipRectY = false;
continue;
}
__m128i topLeft;
__m128i topRight;
__m128i bottomRight;
__m128i bottomLeft;
topLeft = loadUnaligned128((__m128i*)(topLeftBase + x));
topRight = loadUnaligned128((__m128i*)(topRightBase + x));
bottomRight = loadUnaligned128((__m128i*)(bottomRightBase + x));
bottomLeft = loadUnaligned128((__m128i*)(bottomLeftBase + x));
__m128i result1 = BlurFourPixels(topLeft, topRight, bottomRight, bottomLeft, divisor);
topLeft = loadUnaligned128((__m128i*)(topLeftBase + x + 4));
topRight = loadUnaligned128((__m128i*)(topRightBase + x + 4));
bottomRight = loadUnaligned128((__m128i*)(bottomRightBase + x + 4));
bottomLeft = loadUnaligned128((__m128i*)(bottomLeftBase + x + 4));
__m128i result2 = BlurFourPixels(topLeft, topRight, bottomRight, bottomLeft, divisor);
topLeft = loadUnaligned128((__m128i*)(topLeftBase + x + 8));
topRight = loadUnaligned128((__m128i*)(topRightBase + x + 8));
bottomRight = loadUnaligned128((__m128i*)(bottomRightBase + x + 8));
bottomLeft = loadUnaligned128((__m128i*)(bottomLeftBase + x + 8));
__m128i result3 = BlurFourPixels(topLeft, topRight, bottomRight, bottomLeft, divisor);
topLeft = loadUnaligned128((__m128i*)(topLeftBase + x + 12));
topRight = loadUnaligned128((__m128i*)(topRightBase + x + 12));
bottomRight = loadUnaligned128((__m128i*)(bottomRightBase + x + 12));
bottomLeft = loadUnaligned128((__m128i*)(bottomLeftBase + x + 12));
__m128i result4 = BlurFourPixels(topLeft, topRight, bottomRight, bottomLeft, divisor);
__m128i final = _mm_packus_epi16(_mm_packs_epi32(result1, result2), _mm_packs_epi32(result3, result4));
_mm_storeu_si128((__m128i*)(data + stride * y + x), final);
}
// Process the remaining pixels 4 bytes at a time.
for (; x < size.width; x += 4) {
if (inSkipRectY && x > skipRect.x && x < skipRect.XMost()) {
x = skipRect.XMost() - 4;
// Trigger early jump on coming loop iterations, this will be reset
// next line anyway.
inSkipRectY = false;
continue;
}
__m128i topLeft = loadUnaligned128((__m128i*)(topLeftBase + x));
__m128i topRight = loadUnaligned128((__m128i*)(topRightBase + x));
__m128i bottomRight = loadUnaligned128((__m128i*)(bottomRightBase + x));
__m128i bottomLeft = loadUnaligned128((__m128i*)(bottomLeftBase + x));
__m128i result = BlurFourPixels(topLeft, topRight, bottomRight, bottomLeft, divisor);
__m128i final = _mm_packus_epi16(_mm_packs_epi32(result, _mm_setzero_si128()), _mm_setzero_si128());
*(uint32_t*)(data + stride * y + x) = _mm_cvtsi128_si32(final);
}
}
}
}
}
