1ac1ae73dc
That's where it lives in aom/master. Change-Id: I38f405827d9c2d0b06ef5f3bfd7cadc35d5991ef
41 lines
1.1 KiB
C
41 lines
1.1 KiB
C
/*
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* Copyright (c) 2015 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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#ifndef AOM_DSP_DIVIDE_H_
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#define AOM_DSP_DIVIDE_H_
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// An implemntation of the divide by multiply alogrithm
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// https://gmplib.org/~tege/divcnst-pldi94.pdf
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#include <limits.h>
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#include "./aom_config.h"
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#include "aom/aom_integer.h"
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#ifdef __cplusplus
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extern "C" {
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#endif // __cplusplus
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struct fastdiv_elem {
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unsigned mult;
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unsigned shift;
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};
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extern const struct fastdiv_elem av1_fastdiv_tab[256];
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static INLINE unsigned fastdiv(unsigned x, int y) {
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unsigned t =
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((uint64_t)x * av1_fastdiv_tab[y].mult) >> (sizeof(x) * CHAR_BIT);
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return (t + x) >> av1_fastdiv_tab[y].shift;
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}
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#ifdef __cplusplus
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} // extern "C"
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#endif // __cplusplus
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#endif // AOM_DSP_DIVIDE_H_
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