Add MSA optimized I422AlphaToARGBRow_MSA and I422ToRGB24Row_MSA functions

source/convert_from.cc

 /*
  *  Copyright 2012 The LibYuv Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS. All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 540 matching lines @@
   }
 #endif
 #if defined(HAS_I422TORGB24ROW_NEON)
   if (TestCpuFlag(kCpuHasNEON)) {
     I422ToRGB24Row = I422ToRGB24Row_Any_NEON;
     if (IS_ALIGNED(width, 8)) {
       I422ToRGB24Row = I422ToRGB24Row_NEON;
     }
   }
 #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);
     dst_rgb24 += dst_stride_rgb24;
     src_y += src_stride_y;
     if (y & 1) {
       src_u += src_stride_u;
       src_v += src_stride_v;
     }
   }
@@ skipping 540 matching lines @@
     default:
       return -1;  // unknown fourcc - return failure code.
   }
   return r;
 }
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif