eda179764f
This commit replaces an integer divide with a table-lookup. It is to improve decoding speed, and at the same time, to reduce possible complications with a bug in AMD Family 12h processors: "665 Integer Divide Instruction May Cause Unpredictable Behavior" Change-Id: I678b707a538798a923850bac467e66e847e6def7
54 lines
2.3 KiB
C
54 lines
2.3 KiB
C
/*
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* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "vp9/common/vp9_prob.h"
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const uint8_t vp9_norm[256] = {
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0, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
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3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
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2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
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2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
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};
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static unsigned int tree_merge_probs_impl(unsigned int i,
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const vp9_tree_index *tree,
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const vp9_prob *pre_probs,
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const unsigned int *counts,
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vp9_prob *probs) {
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const int l = tree[i];
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const unsigned int left_count = (l <= 0)
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? counts[-l]
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: tree_merge_probs_impl(l, tree, pre_probs, counts, probs);
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const int r = tree[i + 1];
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const unsigned int right_count = (r <= 0)
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? counts[-r]
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: tree_merge_probs_impl(r, tree, pre_probs, counts, probs);
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const unsigned int ct[2] = { left_count, right_count };
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probs[i >> 1] = mode_mv_merge_probs(pre_probs[i >> 1], ct);
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return left_count + right_count;
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}
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void vp9_tree_merge_probs(const vp9_tree_index *tree, const vp9_prob *pre_probs,
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const unsigned int *counts, vp9_prob *probs) {
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tree_merge_probs_impl(0, tree, pre_probs, counts, probs);
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}
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