Files
vortex/sim/common/bitmanip.h
2022-02-04 17:50:19 -05:00

101 lines
2.5 KiB
C++

#pragma once
#include <cstdint>
#include <algorithm>
#include <assert.h>
constexpr uint32_t count_leading_zeros(uint32_t value) {
return value ? __builtin_clz(value) : 32;
}
constexpr uint32_t count_trailing_zeros(uint32_t value) {
return value ? __builtin_ctz(value) : 32;
}
constexpr bool ispow2(uint32_t value) {
return value && !(value & (value - 1));
}
constexpr uint32_t log2ceil(uint32_t value) {
return 32 - count_leading_zeros(value - 1);
}
inline unsigned log2up(uint32_t value) {
return std::max<uint32_t>(1, log2ceil(value));
}
constexpr unsigned log2floor(uint32_t value) {
return 31 - count_leading_zeros(value);
}
constexpr unsigned ceil2(uint32_t value) {
return 32 - count_leading_zeros(value);
}
inline uint64_t bit_clr(uint64_t bits, uint32_t index) {
assert(index <= 63);
return bits & ~(1ull << index);
}
inline uint64_t bit_set(uint64_t bits, uint32_t index) {
assert(index <= 63);
return bits | (1ull << index);
}
inline bool bit_get(uint64_t bits, uint32_t index) {
assert(index <= 63);
return (bits >> index) & 0x1;
}
inline uint64_t bit_clrw(uint64_t bits, uint32_t start, uint32_t end) {
assert(end >= start);
assert(end <= 63);
uint32_t shift = 63 - end;
uint64_t mask = (0xffffffffffffffff << (shift + start)) >> shift;
return bits & ~mask;
}
inline uint64_t bit_setw(uint64_t bits, uint32_t start, uint32_t end, uint64_t value) {
assert(end >= start);
assert(end <= 63);
uint32_t shift = 63 - end;
uint64_t dirty = (value << (shift + start)) >> shift;
return bit_clrw(bits, start, end) | dirty;
}
inline uint64_t bit_getw(uint64_t bits, uint32_t start, uint32_t end) {
assert(end >= start);
assert(end <= 63);
uint32_t shift = 63 - end;
return (bits << shift) >> (shift + start);
}
// Apply integer sign extension
inline uint32_t sext(uint32_t word, uint32_t width) {
assert(width > 1);
assert(width <= 32);
if (width == 32)
return word;
uint32_t mask = (uint32_t(1) << width) - 1;
return ((word >> (width - 1)) & 0x1) ? (word | ~mask) : word;
}
inline uint64_t sext(uint64_t word, uint32_t width) {
assert(width > 1);
assert(width <= 64);
if (width == 64)
return word;
uint64_t mask = (uint64_t(1) << width) - 1;
return ((word >> (width - 1)) & 0x1) ? (word | ~mask) : word;
}
inline __uint128_t sext(__uint128_t word, uint32_t width) {
assert(width > 1);
assert(width <= 128);
if (width == 128)
return word;
__uint128_t mask = (__uint128_t(1) << width) - 1;
return ((word >> (width - 1)) & 0x1) ? (word | ~mask) : word;
}