libcruft-util/bitwise.hpp

74 lines
1.8 KiB
C++

/*
* This file is part of libgim.
*
* libgim 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 of the License, or (at your option) any later
* version.
*
* libgim 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 libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2011 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_BITWISE_HPP
#define __UTIL_BITWISE_HPP
#include <cstdint>
#include "debug.hpp"
const uint8_t BITMASK_1BITS = 0x01;
const uint8_t BITMASK_2BITS = 0x03;
const uint8_t BITMASK_3BITS = 0x07;
const uint8_t BITMASK_4BITS = 0x0F;
const uint8_t BITMASK_5BITS = 0x1F;
const uint8_t BITMASK_6BITS = 0x3F;
const uint8_t BITMASK_7BITS = 0x7F;
const uint8_t BITMASK_8BITS = 0xFF;
#define MODT(x) ((x) % (sizeof (T) * 8))
template <typename T>
constexpr T
rotatel (const T &value, size_t magnitude) {
return (value << MODT (magnitude)) |
(value >> sizeof (value) * 8 - MODT (magnitude));
}
template <typename T>
constexpr T
rotater (const T &value, size_t magnitude) {
return (value >> MODT (magnitude)) |
(value << sizeof (value) * 8 - MODT (magnitude));
}
#undef MODT
// TODO: make constexpr for C++14
template <typename T>
T
reverse (T value) {
T out = value;
size_t bits = sizeof (value) * 8 - 1;
for (value >>= 1; value; value >>= 1) {
out <<= 1;
out |= value & 0x01;
--bits;
}
out <<= bits;
return out;
}
#endif