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| author | Martin Braun <martin.braun@kit.edu> | 2013-02-21 10:38:26 +0100 |
|---|---|---|
| committer | Martin Braun <martin.braun@kit.edu> | 2013-02-21 10:38:26 +0100 |
| commit | 61b90a54cd5b5d452585669498ad2bf692b6e543 (patch) | |
| tree | 75abfe12e76257b2b12b51b4c4986261d79e8b59 /gr-blocks/lib/count_bits.cc | |
| parent | 3b12bc5b360ced033cc45f795dc514dfe99f1588 (diff) | |
| parent | 45c9daa0a7b7dc2316607aa3762e268ce1793dce (diff) | |
Merge branch 'master' of git://github.com/gnuradio/gnuradio into grmodtool
Diffstat (limited to 'gr-blocks/lib/count_bits.cc')
| -rw-r--r-- | gr-blocks/lib/count_bits.cc | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/gr-blocks/lib/count_bits.cc b/gr-blocks/lib/count_bits.cc new file mode 100644 index 0000000000..167396b575 --- /dev/null +++ b/gr-blocks/lib/count_bits.cc @@ -0,0 +1,78 @@ +/* -*- c++ -*- */ +/* + * Copyright 2003,2013 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio 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 3, or (at your option) + * any later version. + * + * GNU Radio 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 GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#include <blocks/count_bits.h> + +/* + * these are slow and obvious. If you need something faster, fix these + * + * Can probably replace with VOLK's popcount + */ + +namespace gr { + namespace blocks { + + unsigned int + count_bits8(unsigned int x) + { + int count = 0; + + for(int i = 0; i < 8; i++) { + if(x & (1 << i)) + count++; + } + + return count; + } + + unsigned int + count_bits16(unsigned int x) + { + int count = 0; + + for(int i = 0; i < 16; i++) { + if(x & (1 << i)) + count++; + } + + return count; + } + + unsigned int + count_bits32(unsigned int x) + { + unsigned res = (x & 0x55555555) + ((x >> 1) & 0x55555555); + res = (res & 0x33333333) + ((res >> 2) & 0x33333333); + res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); + res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); + return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); + } + + unsigned int + count_bits64(unsigned long long x) + { + return count_bits32((x >> 32) & 0xffffffff) + \ + count_bits32(x & 0xffffffff); + } + + } /* namespace blocks */ +} /* namespace gr */ |