Reverting r12568 (ARM Skia NEON patches - 34 - Blur Filter - https://codereview.chromium.org/109403004) due to image quality regressions on the N4.
git-svn-id: http://skia.googlecode.com/svn/trunk/src@12578 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/opts/SkBlurImage_opts_neon.cpp b/opts/SkBlurImage_opts_neon.cpp
index 4e33d72..14907ea 100644
--- a/opts/SkBlurImage_opts_neon.cpp
+++ b/opts/SkBlurImage_opts_neon.cpp
@@ -21,14 +21,16 @@
/**
* 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.
+ * lower 8 bits of each 32-bit element of a NEON register.
*/
-static inline uint16x4_t expand(uint32_t a) {
+inline uint32x4_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));
+ const uint16x4_t v16 = vget_low_u16(vmovl_u8(v8));
+ // ( 0A 0R 0G 0B ) -> ( 000A 000R 000G 000B )
+ return vmovl_u16(v16);
}
template<BlurDirection srcDirection, BlurDirection dstDirection>
@@ -46,7 +48,7 @@
uint32x4_t sum = vdupq_n_u32(0);
const SkPMColor* p = src;
for (int i = 0; i < rightBorder; ++i) {
- sum = vaddw_u16(sum, expand(*p));
+ sum = vaddq_u32(sum, expand(*p));
p += srcStrideX;
}
@@ -56,25 +58,26 @@
// ( 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);
+ // Shift down to lower 8 bits of each element.
+ // ( AAAA RRRR GGGG BBBB ) -> ( 000A 000R 000G 000B )
+ result = vshrq_n_u32(result, 24);
- // Saturated conversion to 8-bit.
+ // ( 000A 000R 000G 000B ) -> ( 0A 0R 0G 0B )
+ uint16x4_t result16 = vqmovn_u32(result);
+
// ( 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);
+ uint8x8_t result8 = vqmovn_u16(vcombine_u16(result16, result16));
// ( 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));
+ sum = vsubq_u32(sum, expand(*l));
}
if (x + rightOffset + 1 < width) {
const SkPMColor* r = sptr + (rightOffset + 1) * srcStrideX;
- sum = vaddw_u16(sum, expand(*r));
+ sum = vaddq_u32(sum, expand(*r));
}
sptr += srcStrideX;
if (srcDirection == kY) {
