ref: d33bf3d6649ce049a12fcf7d629e551066f41c47
parent: 1689564bb5c0f03bb2f35244bf40bcf58c9fec35
author: Yunqing Wang <yunqingwang@google.com>
date: Fri May 28 10:34:39 EDT 2010
Remove costly memory reads/writes in vp8_reset_mb_tokens_context() Tests on x86 showed this function costed 2.7% of total decoding time because of all the memory reads/writes. After modification, it only costs about 0.7% of decoding time, which gives a 2% gain. Change-Id: I5003ee30b6dc6dea0bfa42a6ad7e7c22fcc7b215
--- a/vp8/decoder/detokenize.c
+++ b/vp8/decoder/detokenize.c
@@ -67,23 +67,42 @@
ENTROPY_CONTEXT *l;
int i;
- for (i = 0; i < 24; i++)
- {+ /* Clear entropy contexts for Y blocks */
+ a = A[Y1CONTEXT];
+ l = L[Y1CONTEXT];
+ *a = 0;
+ *(a+1) = 0;
+ *(a+2) = 0;
+ *(a+3) = 0;
+ *l = 0;
+ *(l+1) = 0;
+ *(l+2) = 0;
+ *(l+3) = 0;
- a = A[ vp8_block2context[i] ] + vp8_block2above[i];
- l = L[ vp8_block2context[i] ] + vp8_block2left[i];
+ /* Clear entropy contexts for U blocks */
+ a = A[UCONTEXT];
+ l = L[UCONTEXT];
+ *a = 0;
+ *(a+1) = 0;
+ *l = 0;
+ *(l+1) = 0;
- *a = *l = 0;
- }
+ /* Clear entropy contexts for V blocks */
+ a = A[VCONTEXT];
+ l = L[VCONTEXT];
+ *a = 0;
+ *(a+1) = 0;
+ *l = 0;
+ *(l+1) = 0;
+ /* Clear entropy contexts for Y2 blocks */
if (x->mbmi.mode != B_PRED && x->mbmi.mode != SPLITMV)
{- a = A[Y2CONTEXT] + vp8_block2above[24];
- l = L[Y2CONTEXT] + vp8_block2left[24];
- *a = *l = 0;
+ a = A[Y2CONTEXT];
+ l = L[Y2CONTEXT];
+ *a = 0;
+ *l = 0;
}
-
-
}
DECLARE_ALIGNED(16, extern const unsigned int, vp8dx_bitreader_norm[256]);
#define NORMALIZE \