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author | David Robillard <d@drobilla.net> | 2018-08-04 19:12:43 +0200 |
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committer | David Robillard <d@drobilla.net> | 2018-08-04 20:04:30 +0200 |
commit | 3ea9ed0d2a14468d698dfe24bdb790b6f4103596 (patch) | |
tree | 4452a4920f46bba6fdc67bc2bb56332e456e6be4 /Hilbert/GetBits.hpp | |
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Initial import
Diffstat (limited to 'Hilbert/GetBits.hpp')
-rw-r--r-- | Hilbert/GetBits.hpp | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/Hilbert/GetBits.hpp b/Hilbert/GetBits.hpp new file mode 100644 index 0000000..119ace9 --- /dev/null +++ b/Hilbert/GetBits.hpp @@ -0,0 +1,93 @@ +/* + * Copyright (C) 2006-2007 Chris Hamilton <chamilton@cs.dal.ca> + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef _GETBITS_HPP_ +#define _GETBITS_HPP_ + + +#include <Hilbert/Common.hpp> +#include <Hilbert/BigBitVec.hpp> + + +namespace Hilbert +{ + template <class H,class I> + H_INLINE + void + getBits( + const H &h, // bits to read + int n, // number of bits + int i, // bit index + I &w // destination + ) + { + // This is terribly inefficient. + int j; + for ( j = 0; j < n; j++ ) + w.setBit(j,h.getBit(i+j)); + return; + } + + + // <CBigBitVec,CBigBitVec> + // #TODO + + // <CBigBitVec,CFixBitVec> + template<> + H_INLINE + void + getBits( + const CBigBitVec &h, + int n, + int i, + CFixBitVec &w + ) + { + int ir, ib, t; + BBV_MODSPLIT(ir,ib,i); + w.rack() = h.racks()[ir] >> ib; + t = FBV_BITS - ib; + if ( t < n ) + { + w.rack() |= h.racks()[ir+1] >> (FBV_BITS-n); + } + w.truncate(n); + return; + } + + + // <CFixBitVec,CFixBitVec> + template<> + H_INLINE + void + getBits( + const CFixBitVec &h, + int n, + int i, + CFixBitVec &w + ) + { + w = h >> i; + w.truncate(n); + return; + } + +}; + + +#endif |