fix avx2 box filter bug for yuv down sampling.

source/scale_gcc.cc

 /*
  *  Copyright 2013 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 601 matching lines @@
     "vpxor      %%ymm5,%%ymm5,%%ymm5           \n"
 
     LABELALIGN
   "1:                                          \n"
     "vmovdqu    " MEMACCESS(0) ",%%ymm3        \n"
     "lea        " MEMLEA(0x20,0) ",%0          \n"  // src_ptr += 32
     "vpermq     $0xd8,%%ymm3,%%ymm3            \n"
     "vpunpcklbw %%ymm5,%%ymm3,%%ymm2           \n"
     "vpunpckhbw %%ymm5,%%ymm3,%%ymm3           \n"
     "vpaddusw   " MEMACCESS(1) ",%%ymm2,%%ymm0 \n"
-    "vpaddusw   " MEMACCESS2(0x10,1) ",%%ymm3,%%ymm1 \n"
+    "vpaddusw   " MEMACCESS2(0x20,1) ",%%ymm3,%%ymm1 \n"
     "vmovdqu    %%ymm0," MEMACCESS(1) "        \n"
-    "vmovdqu    %%ymm1," MEMACCESS2(0x10,1) "  \n"
+    "vmovdqu    %%ymm1," MEMACCESS2(0x20,1) "  \n"
     "lea       " MEMLEA(0x40,1) ",%1           \n"
     "sub       $0x20,%2                        \n"
     "jg        1b                              \n"
     "vzeroupper                                \n"
   : "+r"(src_ptr),     // %0
     "+r"(dst_ptr),     // %1
     "+r"(src_width)    // %2
   :
   : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm5"
   );
@@ skipping 462 matching lines @@
   );
   return num;
 }
 
 #endif  // defined(__x86_64__) || defined(__i386__)
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif