Merge "Use divide by multiply in the ans writer." into nextgenv2
diff --git a/aom_dsp/answriter.h b/aom_dsp/answriter.h
index 298b255..370472a 100644
--- a/aom_dsp/answriter.h
+++ b/aom_dsp/answriter.h
@@ -20,8 +20,23 @@
#include "aom_dsp/ans.h"
#include "aom_dsp/prob.h"
#include "aom_ports/mem_ops.h"
+#include "av1/common/odintrin.h"
-#define ANS_DIV(dividend, divisor) ((dividend) / (divisor))
+#if RANS_PRECISION <= OD_DIVU_DMAX
+#define ANS_DIVREM(quotient, remainder, dividend, divisor) \
+ do { \
+ quotient = OD_DIVU_SMALL((dividend), (divisor)); \
+ remainder = (dividend) - (quotient) * (divisor); \
+ } while (0)
+#else
+#define ANS_DIVREM(quotient, remainder, dividend, divisor) \
+ do { \
+ quotient = (dividend) / (divisor); \
+ remainder = (dividend) % (divisor); \
+ } while (0)
+#endif
+
+#define ANS_DIV8(dividend, divisor) OD_DIVU_SMALL((dividend), (divisor))
#ifdef __cplusplus
extern "C" {
@@ -72,9 +87,9 @@
ans->state /= IO_BASE;
}
if (!val)
- ans->state = ANS_DIV(ans->state * ANS_P8_PRECISION, p0);
+ ans->state = ANS_DIV8(ans->state * ANS_P8_PRECISION, p0);
else
- ans->state = ANS_DIV((ans->state + 1) * ANS_P8_PRECISION + p - 1, p) - 1;
+ ans->state = ANS_DIV8((ans->state + 1) * ANS_P8_PRECISION + p - 1, p) - 1;
}
struct rans_sym {
@@ -88,15 +103,17 @@
static INLINE void rans_write(struct AnsCoder *ans,
const struct rans_sym *const sym) {
const aom_cdf_prob p = sym->prob;
+ unsigned quot, rem;
while (ans->state >= L_BASE / RANS_PRECISION * IO_BASE * p) {
ans->buf[ans->buf_offset++] = ans->state % IO_BASE;
ans->state /= IO_BASE;
}
- ans->state =
- (ans->state / p) * RANS_PRECISION + ans->state % p + sym->cum_prob;
+ ANS_DIVREM(quot, rem, ans->state, p);
+ ans->state = quot * RANS_PRECISION + rem + sym->cum_prob;
}
-#undef ANS_DIV
+#undef ANS_DIV8
+#undef ANS_DIVREM
#ifdef __cplusplus
} // extern "C"
#endif // __cplusplus
