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mirror of https://github.com/doitsujin/dxvk.git synced 2024-12-04 16:24:29 +01:00
dxvk/src/util/util_bit.h
2020-01-23 02:05:09 +00:00

266 lines
6.1 KiB
C++

#pragma once
#ifndef _MSC_VER
#if defined(__WINE__) && defined(__clang__)
#pragma push_macro("_WIN32")
#undef _WIN32
#endif
#include <x86intrin.h>
#if defined(__WINE__) && defined(__clang__)
#pragma pop_macro("_WIN32")
#endif
#else
#include <intrin.h>
#endif
#include "util_likely.h"
#include "util_math.h"
#include <cstring>
#include <type_traits>
namespace dxvk::bit {
template<typename T, typename J>
T cast(const J& src) {
static_assert(sizeof(T) == sizeof(J));
static_assert(std::is_trivially_copyable<J>::value && std::is_trivial<T>::value);
T dst;
std::memcpy(&dst, &src, sizeof(T));
return dst;
}
template<typename T>
T extract(T value, uint32_t fst, uint32_t lst) {
return (value >> fst) & ~(~T(0) << (lst - fst + 1));
}
inline uint32_t popcntStep(uint32_t n, uint32_t mask, uint32_t shift) {
return (n & mask) + ((n & ~mask) >> shift);
}
inline uint32_t popcnt(uint32_t n) {
n = popcntStep(n, 0x55555555, 1);
n = popcntStep(n, 0x33333333, 2);
n = popcntStep(n, 0x0F0F0F0F, 4);
n = popcntStep(n, 0x00FF00FF, 8);
n = popcntStep(n, 0x0000FFFF, 16);
return n;
}
inline uint32_t tzcnt(uint32_t n) {
#if defined(_MSC_VER) && !defined(__clang__)
return _tzcnt_u32(n);
#elif defined(__BMI__)
return __tzcnt_u32(n);
#elif defined(__GNUC__) || defined(__clang__)
uint32_t res;
uint32_t tmp;
asm (
"mov $32, %1;"
"bsf %2, %0;"
"cmovz %1, %0;"
: "=&r" (res), "=&r" (tmp)
: "r" (n));
return res;
#else
uint32_t r = 31;
n &= -n;
r -= (n & 0x0000FFFF) ? 16 : 0;
r -= (n & 0x00FF00FF) ? 8 : 0;
r -= (n & 0x0F0F0F0F) ? 4 : 0;
r -= (n & 0x33333333) ? 2 : 0;
r -= (n & 0x55555555) ? 1 : 0;
return n != 0 ? r : 32;
#endif
}
inline uint32_t lzcnt(uint32_t n) {
#if (defined(_MSC_VER) && !defined(__clang__)) || defined(__LZCNT__)
return _lzcnt_u32(n);
#elif defined(__GNUC__) || defined(__clang__)
return n != 0 ? __builtin_clz(n) : 32;
#else
uint32_t r = 0;
if (n == 0) return 32;
if (n <= 0x0000FFFF) { r += 16; n <<= 16; }
if (n <= 0x00FFFFFF) { r += 8; n <<= 8; }
if (n <= 0x0FFFFFFF) { r += 4; n <<= 4; }
if (n <= 0x3FFFFFFF) { r += 2; n <<= 2; }
if (n <= 0x7FFFFFFF) { r += 1; n <<= 1; }
return r;
#endif
}
template<typename T>
uint32_t pack(T& dst, uint32_t& shift, T src, uint32_t count) {
constexpr uint32_t Bits = 8 * sizeof(T);
if (likely(shift < Bits))
dst |= src << shift;
shift += count;
return shift > Bits ? shift - Bits : 0;
}
template<typename T>
uint32_t unpack(T& dst, T src, uint32_t& shift, uint32_t count) {
constexpr uint32_t Bits = 8 * sizeof(T);
if (likely(shift < Bits))
dst = (src >> shift) & ((T(1) << count) - 1);
shift += count;
return shift > Bits ? shift - Bits : 0;
}
/**
* \brief Compares two aligned structs bit by bit
*
* \param [in] a First struct
* \param [in] b Second struct
* \returns \c true if the structs are equal
*/
template<typename T>
bool bcmpeq(const T* a, const T* b) {
static_assert(alignof(T) >= 16);
#if defined(__GNUC__) || defined(__clang__) || defined(_MSC_VER)
auto ai = reinterpret_cast<const __m128i*>(a);
auto bi = reinterpret_cast<const __m128i*>(b);
size_t i = 0;
#if defined(__clang__)
#pragma nounroll
#elif defined(__GNUC__)
#pragma GCC unroll 0
#endif
for ( ; i < 2 * (sizeof(T) / 32); i += 2) {
__m128i eq0 = _mm_cmpeq_epi8(
_mm_load_si128(ai + i),
_mm_load_si128(bi + i));
__m128i eq1 = _mm_cmpeq_epi8(
_mm_load_si128(ai + i + 1),
_mm_load_si128(bi + i + 1));
__m128i eq = _mm_and_si128(eq0, eq1);
int mask = _mm_movemask_epi8(eq);
if (mask != 0xFFFF)
return false;
}
for ( ; i < sizeof(T) / 16; i++) {
__m128i eq = _mm_cmpeq_epi8(
_mm_load_si128(ai + i),
_mm_load_si128(bi + i));
int mask = _mm_movemask_epi8(eq);
if (mask != 0xFFFF)
return false;
}
return true;
#else
return !std::memcmp(a, b, sizeof(T));
#endif
}
template <size_t Bits>
class bitset {
static constexpr size_t Dwords = align(Bits, 32) / 32;
public:
constexpr bitset()
: m_dwords() {
}
constexpr bool get(uint32_t idx) const {
uint32_t dword = 0;
uint32_t bit = idx;
// Compiler doesn't remove this otherwise.
if constexpr (Dwords > 1) {
dword = idx / 32;
bit = idx % 32;
}
return m_dwords[dword] & (1u << bit);
}
constexpr void set(uint32_t idx, bool value) {
uint32_t dword = 0;
uint32_t bit = idx;
// Compiler doesn't remove this otherwise.
if constexpr (Dwords > 1) {
dword = idx / 32;
bit = idx % 32;
}
if (value)
m_dwords[dword] |= 1u << bit;
else
m_dwords[dword] &= ~(1u << bit);
}
constexpr void flip(uint32_t idx) {
uint32_t dword = 0;
uint32_t bit = idx;
// Compiler doesn't remove this otherwise.
if constexpr (Dwords > 1) {
dword = idx / 32;
bit = idx % 32;
}
m_dwords[dword] ^= 1u << bit;
}
constexpr void setAll() {
if constexpr (Bits % 32 == 0) {
for (size_t i = 0; i < Dwords; i++)
m_dwords[i] = std::numeric_limits<uint32_t>::max();
}
else {
for (size_t i = 0; i < Dwords - 1; i++)
m_dwords[i] = std::numeric_limits<uint32_t>::max();
m_dwords[Dwords - 1] = (1u << (Bits % 32)) - 1;
}
}
constexpr bool any() {
for (size_t i = 0; i < Dwords; i++) {
if (m_dwords[i] != 0)
return true;
}
return false;
}
constexpr uint32_t& dword(uint32_t idx) {
return m_dwords[idx];
}
constexpr size_t bitCount() {
return Bits;
}
constexpr size_t dwordCount() {
return Dwords;
}
constexpr bool operator [] (uint32_t idx) const {
return get(idx);
}
private:
uint32_t m_dwords[Dwords];
};
}