libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_subexp.c

 /*
  *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "vp9/common/vp9_common.h"
 #include "vp9/common/vp9_entropy.h"
 
-#include "vp9/encoder/vp9_treewriter.h"
+#include "vp9/encoder/vp9_cost.h"
 #include "vp9/encoder/vp9_writer.h"
 
 #define vp9_cost_upd256  ((int)(vp9_cost_one(upd) - vp9_cost_zero(upd)))
 
 static int update_bits[255];
 
-static int split_index(int i, int n, int modulus) {
-  int max1 = (n - 1 - modulus / 2) / modulus + 1;
-  if (i % modulus == modulus / 2)
-    i = i / modulus;
-  else
-    i = max1 + i - (i + modulus - modulus / 2) / modulus;
-  return i;
-}
-
 static int recenter_nonneg(int v, int m) {
   if (v > (m << 1))
     return v;
   else if (v >= m)
     return ((v - m) << 1);
   else
     return ((m - v) << 1) - 1;
 }
 
 static int remap_prob(int v, int m) {
@@ skipping 153 matching lines @@
                                                           upd);
   assert(newp >= 1);
   if (savings > 0) {
     vp9_write(w, 1, upd);
     vp9_write_prob_diff_update(w, newp, *oldp);
     *oldp = newp;
   } else {
     vp9_write(w, 0, upd);
   }
 }