dingusppc/core/bitops.h

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/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-23 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
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 3 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, see <https://www.gnu.org/licenses/>.
*/
/** Non-standard low-level bitwise operations. */
#ifndef BIT_OPS_H
#define BIT_OPS_H
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#include <cinttypes>
#if defined(__GNUG__) && !defined(__clang__) && (defined(__x86_64__) || defined(__i386__)) // GCC, mybe ICC but not Clang
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# include <x86intrin.h>
# define ROTL_32(x, n) (_rotl((x), (n)))
# define ROTR_32(x, n) (_rotr((x), (n)))
#elif defined(_MSC_VER) // MSVC
# include <intrin.h>
# define ROTL_32(x, n) (_rotl((x), (n)))
# define ROTR_32(x, n) (_rotr((x), (n)))
#else
// cyclic rotation idioms that modern compilers will
// recognize and generate very compact code for
// evolving specific machine instructions
inline unsigned ROTL_32(unsigned x, unsigned n) {
n &= 0x1F;
return (x << n) | (x >> (32 - n));
}
inline unsigned ROTR_32(unsigned x, unsigned n) {
n &= 0x1F;
return (x >> n) | (x << (32 - n));
}
#endif
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template <class T>
inline T extract_bits(T val, int pos, int len) {
return (val >> pos) & (((T)1 << len) - 1);
}
template <class T>
inline void insert_bits(T &old_val, T new_val, int pos, int len) {
T mask = (((T)1 << len) - 1) << pos;
old_val = (old_val & ~mask) | ((new_val << pos) & mask);
}
/* Return true if the specified bit is different in the given numbers. */
static inline bool bit_changed(uint64_t old_val, uint64_t new_val, int bit_num) {
return (old_val ^ new_val) & (1ULL << bit_num);
}
static inline bool bit_set(const uint64_t val, const int bit_num) {
return !!(val & (1ULL << bit_num));
}
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#endif // BIT_OPS_H