libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/dsp/upsampling.c

 // Copyright 2011 Google Inc. All Rights Reserved.
 //
 // This code is licensed under the same terms as WebM:
 //  Software License Agreement:  http://www.webmproject.org/license/software/
 //  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
 // -----------------------------------------------------------------------------
 //
 // YUV to RGB upsampling functions.
 //
 // Author: somnath@google.com (Somnath Banerjee)
@@ skipping 253 matching lines @@
       }
     }
     rgba += stride;
   }
 }
 #undef MULTIPLIER
 #undef PREMULTIPLY
 
 // rgbA4444
 
-#define MULTIPLIER(a)  ((a) * 0x11)
-#define PREMULTIPLY(x, m) (((x) * (m)) >> 12)
+#define MULTIPLIER(a)  ((a) * 0x1111)    // 0x1111 ~= (1 << 16) / 15
 
 static WEBP_INLINE uint8_t dither_hi(uint8_t x) {
   return (x & 0xf0) | (x >> 4);
 }
 
 static WEBP_INLINE uint8_t dither_lo(uint8_t x) {
   return (x & 0x0f) | (x << 4);
 }
 
+static WEBP_INLINE uint8_t multiply(uint8_t x, uint32_t m) {
+  return (x * m) >> 16;
+}
+
 static void ApplyAlphaMultiply4444(uint8_t* rgba4444,
                                    int w, int h, int stride) {
   while (h-- > 0) {
     int i;
     for (i = 0; i < w; ++i) {
-      const uint8_t a = dither_lo(rgba4444[2 * i + 1]);
+      const uint8_t a = (rgba4444[2 * i + 1] & 0x0f);
       const uint32_t mult = MULTIPLIER(a);
-      const uint8_t r = PREMULTIPLY(dither_hi(rgba4444[2 * i + 0]), mult);
-      const uint8_t g = PREMULTIPLY(dither_lo(rgba4444[2 * i + 0]), mult);
-      const uint8_t b = PREMULTIPLY(dither_hi(rgba4444[2 * i + 1]), mult);
-      rgba4444[2 * i + 0] = (r & 0xf0) | (g & 0x0f);
+      const uint8_t r = multiply(dither_hi(rgba4444[2 * i + 0]), mult);
+      const uint8_t g = multiply(dither_lo(rgba4444[2 * i + 0]), mult);
+      const uint8_t b = multiply(dither_hi(rgba4444[2 * i + 1]), mult);
+      rgba4444[2 * i + 0] = (r & 0xf0) | ((g >> 4) & 0x0f);
       rgba4444[2 * i + 1] = (b & 0xf0) | a;
     }
     rgba4444 += stride;
   }
 }
 #undef MULTIPLIER
-#undef PREMULTIPLY
 
 void (*WebPApplyAlphaMultiply)(uint8_t*, int, int, int, int)
     = ApplyAlphaMultiply;
 void (*WebPApplyAlphaMultiply4444)(uint8_t*, int, int, int)
     = ApplyAlphaMultiply4444;
 
 //------------------------------------------------------------------------------
 // Main call
 
 void WebPInitUpsamplers(void) {
 #ifdef FANCY_UPSAMPLING
   WebPUpsamplers[MODE_RGB]       = UpsampleRgbLinePair;
   WebPUpsamplers[MODE_RGBA]      = UpsampleRgbaLinePair;
   WebPUpsamplers[MODE_BGR]       = UpsampleBgrLinePair;
   WebPUpsamplers[MODE_BGRA]      = UpsampleBgraLinePair;
   WebPUpsamplers[MODE_ARGB]      = UpsampleArgbLinePair;
   WebPUpsamplers[MODE_RGBA_4444] = UpsampleRgba4444LinePair;
   WebPUpsamplers[MODE_RGB_565]   = UpsampleRgb565LinePair;
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
 #if defined(WEBP_USE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitUpsamplersSSE2();
     }
 #endif
+#if defined(WEBP_USE_NEON)
+    if (VP8GetCPUInfo(kNEON)) {
+      WebPInitUpsamplersNEON();
+    }
+#endif
   }
 #endif  // FANCY_UPSAMPLING
 }
 
 void WebPInitPremultiply(void) {
   WebPApplyAlphaMultiply = ApplyAlphaMultiply;
   WebPApplyAlphaMultiply4444 = ApplyAlphaMultiply4444;
 
 #ifdef FANCY_UPSAMPLING
   WebPUpsamplers[MODE_rgbA]      = UpsampleRgbaLinePair;
   WebPUpsamplers[MODE_bgrA]      = UpsampleBgraLinePair;
   WebPUpsamplers[MODE_Argb]      = UpsampleArgbLinePair;
   WebPUpsamplers[MODE_rgbA_4444] = UpsampleRgba4444LinePair;
 
   if (VP8GetCPUInfo != NULL) {
 #if defined(WEBP_USE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitPremultiplySSE2();
     }
 #endif
+#if defined(WEBP_USE_NEON)
+    if (VP8GetCPUInfo(kNEON)) {
+      WebPInitPremultiplyNEON();
+    }
+#endif
   }
 #endif  // FANCY_UPSAMPLING
 }
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif