Port morphology to SkOpts.

src/opts/SkBlurImageFilter_opts.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBlurImageFilter_opts_DEFINED
 #define SkBlurImageFilter_opts_DEFINED
 
 #include "SkColorPriv.h"
 #include "SkTypes.h"
 
 namespace SK_OPTS_NS {
 
-enum Direction { kX, kY };
+enum class BlurDirection { kX, kY };
 
 #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
-template<Direction srcDirection, Direction dstDirection>
+template<BlurDirection srcDirection, BlurDirection dstDirection>
 void box_blur(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize,
               int leftOffset, int rightOffset, int width, int height) {
 #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE41
     // ARGB -> 000A 000R 000G 000B
     auto expand = [](int p) {
         return _mm_cvtepu8_epi32(_mm_cvtsi32_si128(p));
     };
     // Axxx Rxxx Gxxx Bxxx -> ARGB
     auto repack = [](__m128i p) {
         const char _ = ~0;  // Don't care what ends up in these bytes.  This zeros them.
@@ skipping 20 matching lines @@
     // _mm_mullo_epi32 is not available, so use the standard trick to emulate it.
     auto _mm_mullo_epi32 = [](__m128i a, __m128i b) {
         __m128i p02 = _mm_mul_epu32(a, b),
                 p13 = _mm_mul_epu32(_mm_srli_si128(a, 4),
                                     _mm_srli_si128(b, 4));
         return _mm_unpacklo_epi32(_mm_shuffle_epi32(p02, _MM_SHUFFLE(0,0,2,0)),
                                   _mm_shuffle_epi32(p13, _MM_SHUFFLE(0,0,2,0)));
     };
 #endif
     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 int srcStrideX = srcDirection == BlurDirection::kX ? 1 : srcStride;
+    const int dstStrideX = dstDirection == BlurDirection::kX ? 1 : height;
+    const int srcStrideY = srcDirection == BlurDirection::kX ? srcStride : 1;
+    const int dstStrideY = dstDirection == BlurDirection::kX ? width : 1;
     const __m128i scale = _mm_set1_epi32((1 << 24) / kernelSize);
     const __m128i half = _mm_set1_epi32(1 << 23);
     for (int y = 0; y < height; ++y) {
         __m128i sum = _mm_setzero_si128();
         const SkPMColor* p = src;
         for (int i = 0; i < rightBorder; ++i) {
             sum = _mm_add_epi32(sum, expand(*p));
             p += srcStrideX;
         }
 
@@ skipping 12 matching lines @@
             // TODO(mtklein): experiment with breaking this loop into 3 parts
             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) {
+            if (srcDirection == BlurDirection::kY) {
                 // TODO(mtklein): experiment with moving this prefetch forward
                 _mm_prefetch(reinterpret_cast<const char*>(sptr + (rightOffset + 1) * srcStrideX),
                              _MM_HINT_T0);
             }
             dptr += dstStrideX;
         }
         src += srcStrideY;
         dst += dstStrideY;
     }
 }
 
 #elif defined(SK_ARM_HAS_NEON)
 
 // Fast path for kernel sizes between 2 and 127, working on two rows at a time.
-template<Direction srcDirection, Direction dstDirection>
+template<BlurDirection srcDirection, BlurDirection dstDirection>
 void box_blur_double(const SkPMColor** src, int srcStride, SkPMColor** dst, int kernelSize,
                      int leftOffset, int rightOffset, int width, int* height) {
     // Load 2 pixels from adjacent rows.
     auto load_2_pixels = [&](const SkPMColor* s) {
-        if (srcDirection == kX) {
+        if (srcDirection == BlurDirection::kX) {
             // 10% faster by adding these 2 prefetches
             SK_PREFETCH(s + 16);
             SK_PREFETCH(s + 16 + srcStride);
             auto one = vld1_lane_u32(s +         0, vdup_n_u32(0), 0),
                  two = vld1_lane_u32(s + srcStride,           one, 1);
             return vreinterpret_u8_u32(two);
         } else {
             return vld1_u8((uint8_t*)s);
         }
     };
     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 int srcStrideX = srcDirection == BlurDirection::kX ? 1 : srcStride;
+    const int dstStrideX = dstDirection == BlurDirection::kX ? 1 : *height;
+    const int srcStrideY = srcDirection == BlurDirection::kX ? srcStride : 1;
+    const int dstStrideY = dstDirection == BlurDirection::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));
             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)));
-            if (dstDirection == kX) {
+            if (dstDirection == BlurDirection::kX) {
                 uint32x2_t px2 = vreinterpret_u32_u8(vmovn_u16(resultPixels));
                 vst1_lane_u32(dptr +     0, px2, 0);
                 vst1_lane_u32(dptr + width, px2, 1);
             } else {
                 vst1_u8((uint8_t*)dptr, vmovn_u16(resultPixels));
             }
 
             if (x >= leftOffset) {
                 sum = vsubw_u8(sum, load_2_pixels(sptr - leftOffset * srcStrideX));
             }
             if (x + rightOffset + 1 < width) {
                 sum = vaddw_u8(sum, load_2_pixels(sptr + (rightOffset + 1) * srcStrideX));
             }
             sptr += srcStrideX;
             dptr += dstStrideX;
         }
         *src += srcStrideY * 2;
         *dst += dstStrideY * 2;
     }
 }
 
-template<Direction srcDirection, Direction dstDirection>
+template<BlurDirection srcDirection, BlurDirection dstDirection>
 void box_blur(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize,
               int leftOffset, int rightOffset, int width, int height) {
     // ARGB -> 0A0R 0G0B
     auto expand = [](uint32_t p) {
         return vget_low_u16(vmovl_u8(vreinterpret_u8_u32(vdup_n_u32(p))));
     };
     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 int srcStrideX = srcDirection == BlurDirection::kX ? 1 : srcStride;
+    const int dstStrideX = dstDirection == BlurDirection::kX ? 1 : height;
+    const int srcStrideY = srcDirection == BlurDirection::kX ? srcStride : 1;
+    const int dstStrideY = dstDirection == BlurDirection::kX ? width : 1;
     const uint32x4_t scale = vdupq_n_u32((1 << 24) / kernelSize);
     const uint32x4_t half = vdupq_n_u32(1 << 23);
 
     if (1 < kernelSize && kernelSize < 128) {
         box_blur_double<srcDirection, dstDirection>(&src, srcStride, &dst, kernelSize,
                                                     leftOffset, rightOffset, width, &height);
     }
 
     for (; height > 0; height--) {
         uint32x4_t sum = vdupq_n_u32(0);
@@ skipping 23 matching lines @@
 
             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) {
+            if (srcDirection == BlurDirection::kX) {
                 SK_PREFETCH(sptr + (rightOffset + 16) * srcStrideX);
             }
             dptr += dstStrideX;
         }
         src += srcStrideY;
         dst += dstStrideY;
     }
 }
 
 #else  // Neither NEON nor >=SSE2.
 
-template<Direction srcDirection, Direction dstDirection>
+template<BlurDirection srcDirection, BlurDirection dstDirection>
 static void box_blur(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize,
                      int leftOffset, int rightOffset, int width, int height) {
     int rightBorder = SkMin32(rightOffset + 1, width);
-    int srcStrideX = srcDirection == kX ? 1 : srcStride;
-    int dstStrideX = dstDirection == kX ? 1 : height;
-    int srcStrideY = srcDirection == kX ? srcStride : 1;
-    int dstStrideY = dstDirection == kX ? width : 1;
+    int srcStrideX = srcDirection == BlurDirection::kX ? 1 : srcStride;
+    int dstStrideX = dstDirection == BlurDirection::kX ? 1 : height;
+    int srcStrideY = srcDirection == BlurDirection::kX ? srcStride : 1;
+    int dstStrideY = dstDirection == BlurDirection::kX ? width : 1;
     uint32_t scale = (1 << 24) / kernelSize;
     uint32_t half = 1 << 23;
     for (int y = 0; y < height; ++y) {
         int sumA = 0, sumR = 0, sumG = 0, sumB = 0;
         const SkPMColor* p = src;
         for (int i = 0; i < rightBorder; ++i) {
             sumA += SkGetPackedA32(*p);
             sumR += SkGetPackedR32(*p);
             sumG += SkGetPackedG32(*p);
             sumB += SkGetPackedB32(*p);
@@ skipping 15 matching lines @@
                 sumB -= SkGetPackedB32(l);
             }
             if (x + rightOffset + 1 < width) {
                 SkColor r = *(sptr + (rightOffset + 1) * srcStrideX);
                 sumA += SkGetPackedA32(r);
                 sumR += SkGetPackedR32(r);
                 sumG += SkGetPackedG32(r);
                 sumB += SkGetPackedB32(r);
             }
             sptr += srcStrideX;
-            if (srcDirection == kY) {
+            if (srcDirection == BlurDirection::kY) {
                 SK_PREFETCH(sptr + (rightOffset + 1) * srcStrideX);
             }
             dptr += dstStrideX;
         }
         src += srcStrideY;
         dst += dstStrideY;
     }
 }
 
 #endif
 
+static auto box_blur_xx = &box_blur<BlurDirection::kX, BlurDirection::kX>,
+            box_blur_xy = &box_blur<BlurDirection::kX, BlurDirection::kY>,
+            box_blur_yx = &box_blur<BlurDirection::kY, BlurDirection::kX>;
+
 }  // namespace SK_OPTS_NS
 
 #endif