EC_ADAPT: faster CDF update.
Also fix warning.
Change-Id: Ia515360af9c3269901eb0d002d326b7af43a00e7
diff --git a/aom_dsp/prob.h b/aom_dsp/prob.h
index 9384ffe..782e4b3 100644
--- a/aom_dsp/prob.h
+++ b/aom_dsp/prob.h
@@ -138,9 +138,21 @@
#if CONFIG_EC_ADAPT
static INLINE void update_cdf(aom_cdf_prob *cdf, int val, int nsymbs) {
const int rate = 4 + get_msb(nsymbs);
- int i, diff, tmp;
+ const int rate2 = 12 - rate;
+ int i, tmp;
+ int diff;
+#if 1
+ const int tmp0 = 1 << rate2;
+ tmp = tmp0;
+ diff = ((32768 - (nsymbs << rate2)) >> rate) << rate;
+ // Single loop (faster)
+ for (i = 0; i < nsymbs - 1; ++i, tmp += tmp0) {
+ tmp += (i == val ? diff : 0);
+ cdf[i] -= ((cdf[i] - tmp) >> rate);
+ }
+#else
for (i = 0; i < nsymbs; ++i) {
- tmp = (i + 1) << (12 - rate);
+ tmp = (i + 1) << rate2;
cdf[i] -= ((cdf[i] - tmp) >> rate);
}
diff = 32768 - cdf[nsymbs - 1];
@@ -148,6 +160,7 @@
for (i = val; i < nsymbs; ++i) {
cdf[i] += diff;
}
+#endif
}
#endif
