Add MIPS SIMD Arch (MSA) optimized MirrorRow function

source/rotate.cc

Index: source/rotate.cc
diff --git a/source/rotate.cc b/source/rotate.cc
index 01ea5c40744fbfb748f5ca2b9b24a8e2232a17a8..cb671f7a4bf4a21b0f7fabea4829cb0eddd8423f 100644
--- a/source/rotate.cc
+++ b/source/rotate.cc
@@ -141,6 +141,11 @@ void RotatePlane180(const uint8* src, int src_stride,
     MirrorRow = MirrorRow_DSPR2;
   }
 #endif
+#if defined(HAS_MIRRORROW_MSA)
+  if (TestCpuFlag(kCpuHasMSA)) {

[fbarchard1, 2016/09/17 01:01:30]

needs an alignment test now:

#if defined(HAS_MIRRORROW_MSA)
   if (TestCpuFlag(kCpuHasMSA)) {
     MirrorRow = MirrorRow_Any_MSA;
     if (IS_ALIGNED(width, 64)) {
       MirrorRow = MirrorRow_MSA;
     }
   }
#endif

[manojkumar.bhosale, 2016/09/19 08:07:21]

Done.

+    MirrorRow = MirrorRow_MSA;
+  }
+#endif
 #if defined(HAS_COPYROW_SSE2)
   if (TestCpuFlag(kCpuHasSSE2)) {
     CopyRow = IS_ALIGNED(width, 32) ? CopyRow_SSE2 : CopyRow_Any_SSE2;