df72480395
Now that clang-format makes [[nodiscard]] attributes format sensibly, we can apply them to several functions within the common library to allow the compiler to complain about any misuses of the functions.
145 lines
3.1 KiB
C++
145 lines
3.1 KiB
C++
// Copyright 2018 yuzu emulator team
|
|
// Licensed under GPLv2 or any later version
|
|
// Refer to the license.txt file included.
|
|
|
|
#pragma once
|
|
|
|
#include <climits>
|
|
#include <cstddef>
|
|
|
|
#ifdef _MSC_VER
|
|
#include <intrin.h>
|
|
#endif
|
|
|
|
#include "common/common_types.h"
|
|
|
|
namespace Common {
|
|
|
|
/// Gets the size of a specified type T in bits.
|
|
template <typename T>
|
|
[[nodiscard]] constexpr std::size_t BitSize() {
|
|
return sizeof(T) * CHAR_BIT;
|
|
}
|
|
|
|
#ifdef _MSC_VER
|
|
[[nodiscard]] inline u32 CountLeadingZeroes32(u32 value) {
|
|
unsigned long leading_zero = 0;
|
|
|
|
if (_BitScanReverse(&leading_zero, value) != 0) {
|
|
return 31 - leading_zero;
|
|
}
|
|
|
|
return 32;
|
|
}
|
|
|
|
[[nodiscard]] inline u32 CountLeadingZeroes64(u64 value) {
|
|
unsigned long leading_zero = 0;
|
|
|
|
if (_BitScanReverse64(&leading_zero, value) != 0) {
|
|
return 63 - leading_zero;
|
|
}
|
|
|
|
return 64;
|
|
}
|
|
#else
|
|
[[nodiscard]] inline u32 CountLeadingZeroes32(u32 value) {
|
|
if (value == 0) {
|
|
return 32;
|
|
}
|
|
|
|
return static_cast<u32>(__builtin_clz(value));
|
|
}
|
|
|
|
[[nodiscard]] inline u32 CountLeadingZeroes64(u64 value) {
|
|
if (value == 0) {
|
|
return 64;
|
|
}
|
|
|
|
return static_cast<u32>(__builtin_clzll(value));
|
|
}
|
|
#endif
|
|
|
|
#ifdef _MSC_VER
|
|
[[nodiscard]] inline u32 CountTrailingZeroes32(u32 value) {
|
|
unsigned long trailing_zero = 0;
|
|
|
|
if (_BitScanForward(&trailing_zero, value) != 0) {
|
|
return trailing_zero;
|
|
}
|
|
|
|
return 32;
|
|
}
|
|
|
|
[[nodiscard]] inline u32 CountTrailingZeroes64(u64 value) {
|
|
unsigned long trailing_zero = 0;
|
|
|
|
if (_BitScanForward64(&trailing_zero, value) != 0) {
|
|
return trailing_zero;
|
|
}
|
|
|
|
return 64;
|
|
}
|
|
#else
|
|
[[nodiscard]] inline u32 CountTrailingZeroes32(u32 value) {
|
|
if (value == 0) {
|
|
return 32;
|
|
}
|
|
|
|
return static_cast<u32>(__builtin_ctz(value));
|
|
}
|
|
|
|
[[nodiscard]] inline u32 CountTrailingZeroes64(u64 value) {
|
|
if (value == 0) {
|
|
return 64;
|
|
}
|
|
|
|
return static_cast<u32>(__builtin_ctzll(value));
|
|
}
|
|
#endif
|
|
|
|
#ifdef _MSC_VER
|
|
|
|
[[nodiscard]] inline u32 MostSignificantBit32(const u32 value) {
|
|
unsigned long result;
|
|
_BitScanReverse(&result, value);
|
|
return static_cast<u32>(result);
|
|
}
|
|
|
|
[[nodiscard]] inline u32 MostSignificantBit64(const u64 value) {
|
|
unsigned long result;
|
|
_BitScanReverse64(&result, value);
|
|
return static_cast<u32>(result);
|
|
}
|
|
|
|
#else
|
|
|
|
[[nodiscard]] inline u32 MostSignificantBit32(const u32 value) {
|
|
return 31U - static_cast<u32>(__builtin_clz(value));
|
|
}
|
|
|
|
[[nodiscard]] inline u32 MostSignificantBit64(const u64 value) {
|
|
return 63U - static_cast<u32>(__builtin_clzll(value));
|
|
}
|
|
|
|
#endif
|
|
|
|
[[nodiscard]] inline u32 Log2Floor32(const u32 value) {
|
|
return MostSignificantBit32(value);
|
|
}
|
|
|
|
[[nodiscard]] inline u32 Log2Ceil32(const u32 value) {
|
|
const u32 log2_f = Log2Floor32(value);
|
|
return log2_f + ((value ^ (1U << log2_f)) != 0U);
|
|
}
|
|
|
|
[[nodiscard]] inline u32 Log2Floor64(const u64 value) {
|
|
return MostSignificantBit64(value);
|
|
}
|
|
|
|
[[nodiscard]] inline u32 Log2Ceil64(const u64 value) {
|
|
const u64 log2_f = static_cast<u64>(Log2Floor64(value));
|
|
return static_cast<u32>(log2_f + ((value ^ (1ULL << log2_f)) != 0ULL));
|
|
}
|
|
|
|
} // namespace Common
|