diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/opts/SkBlurImage_opts_neon.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/src/opts/SkBlurImage_opts_neon.cpp Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,188 @@ +/* + * 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 "SkBitmap.h" +#include "SkColorPriv.h" +#include "SkBlurImage_opts.h" +#include "SkRect.h" + +#include + +namespace { + +enum BlurDirection { + kX, kY +}; + +/** + * Helper function to load 2 pixels from diffent rows to a 8x8 NEON register + * and also pre-load pixels for future read + */ +template +inline uint8x8_t load_2_pixels(const SkPMColor* src, int srcStride) { + if (srcDirection == kX) { + uint32x2_t temp = vdup_n_u32(0); + // 10% faster by adding these 2 prefetches + SK_PREFETCH(src + 16); + SK_PREFETCH(src + srcStride + 16); + return vreinterpret_u8_u32(vld1_lane_u32(src + srcStride, vld1_lane_u32(src, temp, 0), 1)); + } else { + return vld1_u8((uint8_t*)src); + } +} + +/** + * Helper function to store the low 8-bits from a 16x8 NEON register to 2 rows + */ +template +inline void store_2_pixels(uint16x8_t result16x8, SkPMColor* dst, int dstStride) { + if (dstDirection == kX) { + uint32x2_t temp = vreinterpret_u32_u8(vmovn_u16(result16x8)); + vst1_lane_u32(dst, temp, 0); + vst1_lane_u32(dst + dstStride, temp, 1); + } else { + uint8x8_t temp = vmovn_u16(result16x8); + vst1_u8((uint8_t*)dst, temp); + } +} + +/** + * fast path for kernel size less than 128 + */ +template +void SkDoubleRowBoxBlur_NEON(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 uint16x8_t scale = vdupq_n_u16((1 << 15) / kernelSize); + + for (; *height >= 2; *height -= 2) { + uint16x8_t sum = vdupq_n_u16(0); + const SkPMColor* p = *src; + for (int i = 0; i < rightBorder; i++) { + sum = vaddw_u8(sum, + load_2_pixels(p, srcStride)); + p += srcStrideX; + } + + const SkPMColor* sptr = *src; + SkPMColor* dptr = *dst; + for (int x = 0; x < width; x++) { + // val = (sum * scale * 2 + 0x8000) >> 16 + uint16x8_t resultPixels = vreinterpretq_u16_s16(vqrdmulhq_s16( + vreinterpretq_s16_u16(sum), vreinterpretq_s16_u16(scale))); + store_2_pixels(resultPixels, dptr, width); + + if (x >= leftOffset) { + sum = vsubw_u8(sum, + load_2_pixels(sptr - leftOffset * srcStrideX, srcStride)); + } + if (x + rightOffset + 1 < width) { + sum = vaddw_u8(sum, + load_2_pixels(sptr + (rightOffset + 1) * srcStrideX, srcStride)); + } + sptr += srcStrideX; + dptr += dstStrideX; + } + *src += srcStrideY * 2; + *dst += dstStrideY * 2; + } +} + + +/** + * Helper function to spread the components of a 32-bit integer into the + * lower 8 bits of each 16-bit element of a NEON register. + */ + +static inline uint16x4_t expand(uint32_t a) { + // ( ARGB ) -> ( ARGB ARGB ) -> ( A R G B A R G B ) + uint8x8_t v8 = vreinterpret_u8_u32(vdup_n_u32(a)); + // ( A R G B A R G B ) -> ( 0A 0R 0G 0B 0A 0R 0G 0B ) -> ( 0A 0R 0G 0B ) + return vget_low_u16(vmovl_u8(v8)); +} + +template +void SkBoxBlur_NEON(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 uint32x4_t scale = vdupq_n_u32((1 << 24) / kernelSize); + const uint32x4_t half = vdupq_n_u32(1 << 23); + + if (kernelSize < 128) + { + SkDoubleRowBoxBlur_NEON(&src, srcStride, &dst, kernelSize, + leftOffset, rightOffset, width, &height); + } + + for (; height > 0; height--) { + uint32x4_t sum = vdupq_n_u32(0); + const SkPMColor* p = src; + for (int i = 0; i < rightBorder; ++i) { + sum = vaddw_u16(sum, expand(*p)); + p += srcStrideX; + } + + const SkPMColor* sptr = src; + SkPMColor* dptr = dst; + for (int x = 0; x < width; ++x) { + // ( half+sumA*scale half+sumR*scale half+sumG*scale half+sumB*scale ) + uint32x4_t result = vmlaq_u32(half, sum, scale); + + // Saturated conversion to 16-bit. + // ( AAAA RRRR GGGG BBBB ) -> ( 0A 0R 0G 0B ) + uint16x4_t result16 = vqshrn_n_u32(result, 16); + + // Saturated conversion to 8-bit. + // ( 0A 0R 0G 0B ) -> ( 0A 0R 0G 0B 0A 0R 0G 0B ) -> ( A R G B A R G B ) + uint8x8_t result8 = vqshrn_n_u16(vcombine_u16(result16, result16), 8); + + // ( A R G B A R G B ) -> ( ARGB ARGB ) -> ( ARGB ) + // Store low 32 bits to destination. + vst1_lane_u32(dptr, vreinterpret_u32_u8(result8), 0); + + if (x >= leftOffset) { + const SkPMColor* l = sptr - leftOffset * srcStrideX; + sum = vsubw_u16(sum, expand(*l)); + } + if (x + rightOffset + 1 < width) { + const SkPMColor* r = sptr + (rightOffset + 1) * srcStrideX; + sum = vaddw_u16(sum, expand(*r)); + } + sptr += srcStrideX; + if (srcDirection == kX) { + SK_PREFETCH(sptr + (rightOffset + 16) * srcStrideX); + } + dptr += dstStrideX; + } + src += srcStrideY; + dst += dstStrideY; + } +} + +} // namespace + +bool SkBoxBlurGetPlatformProcs_NEON(SkBoxBlurProc* boxBlurX, + SkBoxBlurProc* boxBlurY, + SkBoxBlurProc* boxBlurXY, + SkBoxBlurProc* boxBlurYX) { + *boxBlurX = SkBoxBlur_NEON; + *boxBlurY = SkBoxBlur_NEON; + *boxBlurXY = SkBoxBlur_NEON; + *boxBlurYX = SkBoxBlur_NEON; + return true; +}