| /* libFLAC - Free Lossless Audio Codec library |
| * Copyright (C) 2001-2009 Josh Coalson |
| * Copyright (C) 2011-2016 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 |
| */ |
| unsigned 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; |
| } |
