Add an emms instruction to vpx_subtract_block

This CL adds an `emms` instruction at the end of the MMX assembly
for the vpx_subtract_block function, to properly clear the register
state. This resolves a mismatch between x86 build and C only build.

BUG=webm:1816

Change-Id: I79d2947da7f587f3558a2ae17df214d2faf59e74

diff --git a/vpx_dsp/x86/subtract_sse2.asm b/vpx_dsp/x86/subtract_sse2.asm
index 4273efb..e3055ab 100644 (file)
--- a/vpx_dsp/x86/subtract_sse2.asm
+++ b/vpx_dsp/x86/subtract_sse2.asm
@@ -124,4 +124,5 @@ INIT_MMX
   lea                predq, [predq+pred_str*2]
   sub                rowsd, 2
   jg .loop_4
+  emms
   RET