Add MSA optimized I422ToYUY2Row, I422ToUYVYRow functions

source/row_msa.cc

 /*
  *  Copyright 2016 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 35 matching lines @@
   for (x = 0; x < width; x += 16) {
     LD_UB4(src, 16, src3, src2, src1, src0);
     VSHF_B2_UB(src3, src3, src2, src2, shuffler, shuffler, dst3, dst2);
     VSHF_B2_UB(src1, src1, src0, src0, shuffler, shuffler, dst1, dst0);
     ST_UB4(dst0, dst1, dst2, dst3, dst, 16);
     dst += 64;
     src -= 64;
   }
 }
 
+void I422ToYUY2Row_MSA(const uint8* src_y,
+                       const uint8* src_u,
+                       const uint8* src_v,
+                       uint8* dst_yuy2,
+                       int width) {
+  int x;
+  v16u8 src_u0, src_v0, src_y0, src_y1, vec_uv0, vec_uv1;
+  v16u8 dst_yuy2_0, dst_yuy2_1, dst_yuy2_2, dst_yuy2_3;
+
+  for (x = 0; x < width; x += 32) {
+    src_u0 = LD_UB(src_u);
+    src_v0 = LD_UB(src_v);
+    LD_UB2(src_y, 16, src_y0, src_y1);
+    ILVRL_B2_UB(src_v0, src_u0, vec_uv0, vec_uv1);

[fbarchard1, 2016/09/29 17:10:43]

Did you try just 1 vector at a time instead of 2?  Is it improving performance
much to unroll all instructions to 2?

[manojkumar.bhosale, 2016/09/30 09:00:29]

all the loop unrolling we have done is based on load latencies and to reduce
un-necessary stalls. Here, byte vector holds 16 elements of u and v after load,
so we needed 2 loads of y and hence all subsequent operations with 2
instructions.
Operating 1 y vector at a time is possible but then we will be wasting half of
the u and v elements getting loaded anyway, will insert more stalls which will
be un-optimal.

+    ILVRL_B2_UB(vec_uv0, src_y0, dst_yuy2_0, dst_yuy2_1);
+    ILVRL_B2_UB(vec_uv1, src_y1, dst_yuy2_2, dst_yuy2_3);
+    ST_UB4(dst_yuy2_0, dst_yuy2_1, dst_yuy2_2, dst_yuy2_3, dst_yuy2, 16);
+    src_u += 16;
+    src_v += 16;
+    src_y += 32;
+    dst_yuy2 += 64;
+  }
+}
+
+void I422ToUYVYRow_MSA(const uint8* src_y,
+                       const uint8* src_u,
+                       const uint8* src_v,
+                       uint8* dst_uyvy,
+                       int width) {
+  int x;
+  v16u8 src_u0, src_v0, src_y0, src_y1, vec_uv0, vec_uv1;
+  v16u8 dst_uyvy0, dst_uyvy1, dst_uyvy2, dst_uyvy3;
+
+  for (x = 0; x < width; x += 32) {
+    src_u0 = LD_UB(src_u);
+    src_v0 = LD_UB(src_v);
+    LD_UB2(src_y, 16, src_y0, src_y1);
+    ILVRL_B2_UB(src_v0, src_u0, vec_uv0, vec_uv1);
+    ILVRL_B2_UB(src_y0, vec_uv0, dst_uyvy0, dst_uyvy1);
+    ILVRL_B2_UB(src_y1, vec_uv1, dst_uyvy2, dst_uyvy3);
+    ST_UB4(dst_uyvy0, dst_uyvy1, dst_uyvy2, dst_uyvy3, dst_uyvy, 16);
+    src_u += 16;
+    src_v += 16;
+    src_y += 32;
+    dst_uyvy += 64;
+  }
+}
+
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif
 
 #endif  // !defined(LIBYUV_DISABLE_MSA) && defined(__mips_msa)