Port SkBlurImage opts to SkOpts.

src/opts/SkBlurImage_opts_SSE2.cpp

-/*
- * 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* boxBlurXY,
-                                    SkBoxBlurProc* boxBlurYX) {
-    *boxBlurX = SkBoxBlur_SSE2<kX, kX>;
-    *boxBlurXY = SkBoxBlur_SSE2<kX, kY>;
-    *boxBlurYX = SkBoxBlur_SSE2<kY, kX>;
-    return true;
-}