Resubmit - Use SSE2 block differ for chromoting

remoting/host/differ.cc

Index: remoting/host/differ.cc
diff --git a/remoting/host/differ.cc b/remoting/host/differ.cc
index c7d28b0159a2d6c4d736781551f6ce86071cf38b..c473870222cc881ba85cbbe38444bc6aaf7cd084 100644
--- a/remoting/host/differ.cc
+++ b/remoting/host/differ.cc
@@ -5,6 +5,7 @@
 #include "remoting/host/differ.h"
 
 #include "base/logging.h"
+#include "remoting/host/differ_block.h"
 
 namespace remoting {
 
@@ -72,7 +73,7 @@ void Differ::MarkDirtyBlocks(const void* prev_buffer, const void* curr_buffer) {
     uint8* diff_info = diff_info_row_start;
 
     for (int x = 0; x < x_full_blocks; x++) {
-      DiffInfo diff = DiffBlock(prev_block, curr_block, bytes_per_row_);
+      DiffInfo diff = BlockDifference(prev_block, curr_block, bytes_per_row_);
       if (diff != 0) {
         // Mark this block as being modified so that it gets incorporated into
         // a dirty rect.
@@ -98,35 +99,6 @@ void Differ::MarkDirtyBlocks(const void* prev_buffer, const void* curr_buffer) {
   }
 }
 
-DiffInfo Differ::DiffBlock(const uint8* prev_buffer, const uint8* curr_buffer,
-                           int stride) {
-  const uint8* prev_row_start = prev_buffer;
-  const uint8* curr_row_start = curr_buffer;
-
-  // Number of uint64s in each row of the block.
-  // This must be an integral number.
-  int int64s_per_row = (kBlockSize * bytes_per_pixel_) / sizeof(uint64);
-  DCHECK(((kBlockSize * bytes_per_pixel_) % sizeof(uint64)) == 0);
-
-  for (int y = 0; y < kBlockSize; y++) {
-    const uint64* prev = reinterpret_cast<const uint64*>(prev_row_start);
-    const uint64* curr = reinterpret_cast<const uint64*>(curr_row_start);
-
-    // Check each row in uint64-sized chunks.
-    // Note that this check may straddle multiple pixels. This is OK because
-    // we're interested in identifying whether or not there was change - we
-    // don't care what the actual change is.
-    for (int x = 0; x < int64s_per_row; x++) {
-      if (*prev++ != *curr++) {
-        return 1;
-      }
-    }
-    prev_row_start += stride;
-    curr_row_start += stride;
-  }
-  return 0;
-}
-
 DiffInfo Differ::DiffPartialBlock(const uint8* prev_buffer,
                                   const uint8* curr_buffer,
                                   int stride, int width, int height) {