Add MSA optimized I422AlphaToARGBRow_MSA and I422ToRGB24Row_MSA functions

source/convert_from.cc

Index: source/convert_from.cc
diff --git a/source/convert_from.cc b/source/convert_from.cc
index 7847622cdf856908b1944c60c9aa3c465e60913e..9859f5f3b68c35621e1a741822d0ca6e1a493f64 100644
--- a/source/convert_from.cc
+++ b/source/convert_from.cc
@@ -558,6 +558,14 @@ static int I420ToRGB24Matrix(const uint8* src_y, int src_stride_y,
     }
   }
 #endif
+#if defined(HAS_I422TORGB24ROW_MSA)
+  if (TestCpuFlag(kCpuHasMSA)) {
+    I422ToRGB24Row = I422ToRGB24Row_Any_MSA;

[fbarchard1, 2016/10/26 17:56:31]

when doing RGB24, its good to do RAW at the same time.  Its the same, but with
R,G,B memory ordering, vs RGB24 is B,G,R.
Neither are commonly used, but they come as a pair.

+    if (IS_ALIGNED(width, 16)) {
+      I422ToRGB24Row = I422ToRGB24Row_MSA;
+    }
+  }
+#endif
 
   for (y = 0; y < height; ++y) {
     I422ToRGB24Row(src_y, src_u, src_v, dst_rgb24, yuvconstants, width);