chromium/third_party/flac/src/libFLAC/include/private/bitmath.h

/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2001-2009  Josh Coalson
 * Copyright (C) 2011-2022  Xiph.Org Foundation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FLAC__PRIVATE__BITMATH_H
#define FLAC__PRIVATE__BITMATH_H

#include "FLAC/ordinals.h"
#include "FLAC/assert.h"

#include "share/compat.h"

#if defined(_MSC_VER)
#include <intrin.h> /* for _BitScanReverse* */
#endif

/* Will never be emitted for MSVC, GCC, Intel compilers */
static inline uint32_t FLAC__clz_soft_uint32(FLAC__uint32 word) { … }

static inline uint32_t FLAC__clz_uint32(FLAC__uint32 v) { … }

/* Used when 64-bit bsr/clz is unavailable; can use 32-bit bsr/clz when possible
 */
static inline uint32_t FLAC__clz_soft_uint64(FLAC__uint64 word) { … }

static inline uint32_t FLAC__clz_uint64(FLAC__uint64 v) { … }

/* These two functions work with input 0 */
static inline uint32_t FLAC__clz2_uint32(FLAC__uint32 v) { … }

static inline uint32_t FLAC__clz2_uint64(FLAC__uint64 v) { … }

/* An example of what FLAC__bitmath_ilog2() computes:
 *
 * ilog2( 0) = assertion failure
 * ilog2( 1) = 0
 * ilog2( 2) = 1
 * ilog2( 3) = 1
 * ilog2( 4) = 2
 * ilog2( 5) = 2
 * ilog2( 6) = 2
 * ilog2( 7) = 2
 * ilog2( 8) = 3
 * ilog2( 9) = 3
 * ilog2(10) = 3
 * ilog2(11) = 3
 * ilog2(12) = 3
 * ilog2(13) = 3
 * ilog2(14) = 3
 * ilog2(15) = 3
 * ilog2(16) = 4
 * ilog2(17) = 4
 * ilog2(18) = 4
 */

static inline uint32_t FLAC__bitmath_ilog2(FLAC__uint32 v) { … }

static inline uint32_t FLAC__bitmath_ilog2_wide(FLAC__uint64 v) { … }

uint32_t FLAC__bitmath_silog2(FLAC__int64 v);

#endif