| /* libFLAC - Free Lossless Audio Codec library | |
| * Copyright (C) 2001-2009 Josh Coalson | |
| * Copyright (C) 2011-2023 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. | |
| */ | |
| #ifdef HAVE_CONFIG_H | |
| # include <config.h> | |
| #endif | |
| #include "private/bitmath.h" | |
| /* An example of what FLAC__bitmath_silog2() computes: | |
| * | |
| * silog2(-10) = 5 | |
| * silog2(- 9) = 5 | |
| * silog2(- 8) = 4 | |
| * silog2(- 7) = 4 | |
| * silog2(- 6) = 4 | |
| * silog2(- 5) = 4 | |
| * silog2(- 4) = 3 | |
| * silog2(- 3) = 3 | |
| * silog2(- 2) = 2 | |
| * silog2(- 1) = 2 | |
| * silog2( 0) = 0 | |
| * silog2( 1) = 2 | |
| * silog2( 2) = 3 | |
| * silog2( 3) = 3 | |
| * silog2( 4) = 4 | |
| * silog2( 5) = 4 | |
| * silog2( 6) = 4 | |
| * silog2( 7) = 4 | |
| * silog2( 8) = 5 | |
| * silog2( 9) = 5 | |
| * silog2( 10) = 5 | |
| */ | |
| uint32_t FLAC__bitmath_silog2(FLAC__int64 v) | |
| { | |
| if(v == 0) | |
| return 0; | |
| if(v == -1) | |
| return 2; | |
| v = (v < 0) ? (-(v+1)) : v; | |
| return FLAC__bitmath_ilog2_wide(v)+2; | |
| } |