2 * Copyright 2006 Free Software Foundation, Inc.
4 * This file is part of GNU Radio
6 * GNU Radio is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3, or (at your option)
11 * GNU Radio is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with GNU Radio; see the file COPYING. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street,
19 * Boston, MA 02110-1301, USA.
26 #include <pageri_util.h>
28 unsigned char pageri_reverse_bits8(unsigned char val)
30 // This method was attributed to Rich Schroeppel in the Programming
31 // Hacks section of Beeler, M., Gosper, R. W., and Schroeppel, R.
32 // HAKMEM. MIT AI Memo 239, Feb. 29, 1972.
34 // Reverses 8 bits in 5 machine operations with 64 bit arch
35 return (val * 0x0202020202ULL & 0x010884422010ULL) % 1023;
38 gr_int32 pageri_reverse_bits32(gr_int32 val)
40 gr_int32 out = 0x00000000;
41 out |= (pageri_reverse_bits8((val >> 24) & 0x000000FF) );
42 out |= (pageri_reverse_bits8((val >> 16) & 0x000000FF) << 8);
43 out |= (pageri_reverse_bits8((val >> 8) & 0x000000FF) << 16);
44 out |= (pageri_reverse_bits8((val ) & 0x000000FF) << 24);