/* * Copyright 2003-2019 The Music Player Daemon Project * http://www.musicpd.org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "bit_reverse.h" /** * @see http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable */ const uint8_t bit_reverse_table[256] = { #define R2(n) n, n + 2*64, n + 1*64, n + 3*64 #define R4(n) R2(n), R2(n + 2*16), R2(n + 1*16), R2(n + 3*16) #define R6(n) R4(n), R4(n + 2*4 ), R4(n + 1*4 ), R4(n + 3*4 ) R6(0), R6(2), R6(1), R6(3) };