The Tor Browser: gfx/skia/trunk/src/opts/SkBlurImage_opts

gfx/skia/trunk/src/opts/SkBlurImage_opts_neon.cpp@6474c204b198 (annotated)

gfx/skia/trunk/src/opts/SkBlurImage_opts_neon.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * 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 <arm_neon.h>
 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<BlurDirection srcDirection>
 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<BlurDirection dstDirection>
 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<BlurDirection srcDirection, BlurDirection dstDirection>
 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<srcDirection>(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<dstDirection>(resultPixels, dptr, width);
             if (x >= leftOffset) {
                 sum = vsubw_u8(sum,
                     load_2_pixels<srcDirection>(sptr - leftOffset * srcStrideX, srcStride));
             }
             if (x + rightOffset + 1 < width) {
                 sum = vaddw_u8(sum,
                     load_2_pixels<srcDirection>(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<BlurDirection srcDirection, BlurDirection dstDirection>
 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<srcDirection, dstDirection>(&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<kX, kX>;
     *boxBlurY = SkBoxBlur_NEON<kY, kY>;
     *boxBlurXY = SkBoxBlur_NEON<kX, kY>;
     *boxBlurYX = SkBoxBlur_NEON<kY, kX>;
     return true;
 }

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gfx/skia/trunk/src/opts/SkBlurImage_opts_neon.cpp@6474c204b198 (annotated)

gfx/skia/trunk/src/opts/SkBlurImage_opts_neon.cpp