shithub: libvpx

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Merge changes I11786887,Ia91823ad

* changes:
  vpx_dsp/get_prob: relocate den == 0 test
  vpx_dsp/get_prob: make clip_prob branchless

--- a/vpx_dsp/prob.h

+++ b/vpx_dsp/prob.h

@@ -11,6 +11,8 @@

 #ifndef VPX_DSP_PROB_H_

 #define VPX_DSP_PROB_H_

+#include <assert.h>

+

 #include "./vpx_config.h"

 #include "./vpx_dsp_common.h"

@@ -43,17 +45,20 @@

 typedef const vpx_tree_index vpx_tree[];

-static INLINE vpx_prob clip_prob(int p) {

-  return (p > 255) ? 255 : (p < 1) ? 1 : p;

-}

-

 static INLINE vpx_prob get_prob(unsigned int num, unsigned int den) {

-  if (den == 0) return 128u;

-  return clip_prob((int)(((int64_t)num * 256 + (den >> 1)) / den));

+  assert(den != 0);

+  {

+    const int p = (int)(((int64_t)num * 256 + (den >> 1)) / den);

+    // (p > 255) ? 255 : (p < 1) ? 1 : p;

+    const int clipped_prob = p | ((255 - p) >> 23) | (p == 0);

+    return (vpx_prob)clipped_prob;

+  }

 }

 static INLINE vpx_prob get_binary_prob(unsigned int n0, unsigned int n1) {

-  return get_prob(n0, n0 + n1);

+  const unsigned int den = n0 + n1;

+  if (den == 0) return 128u;

+  return get_prob(n0, den);

 }

 /* This function assumes prob1 and prob2 are already within [1,255] range. */