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author | Lioncash <mathew1800@gmail.com> | 2018-12-19 21:25:12 +0100 |
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committer | Lioncash <mathew1800@gmail.com> | 2018-12-21 13:04:18 +0100 |
commit | fc8da2d5e36b665dae784ee8e9915dfffb379830 (patch) | |
tree | 9364f2a3d986820e7f01096c27710b23f4622b98 /src/common/bit_util.h | |
parent | Merge pull request #1907 from lioncash/attribute (diff) | |
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Diffstat (limited to '')
-rw-r--r-- | src/common/bit_util.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/common/bit_util.h b/src/common/bit_util.h new file mode 100644 index 000000000..1eea17ba1 --- /dev/null +++ b/src/common/bit_util.h @@ -0,0 +1,61 @@ +// 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> +constexpr std::size_t BitSize() { + return sizeof(T) * CHAR_BIT; +} + +#ifdef _MSC_VER +inline u32 CountLeadingZeroes32(u32 value) { + unsigned long leading_zero = 0; + + if (_BitScanReverse(&leading_zero, value) != 0) { + return 31 - leading_zero; + } + + return 32; +} + +inline u64 CountLeadingZeroes64(u64 value) { + unsigned long leading_zero = 0; + + if (_BitScanReverse64(&leading_zero, value) != 0) { + return 63 - leading_zero; + } + + return 64; +} +#else +inline u32 CountLeadingZeroes32(u32 value) { + if (value == 0) { + return 32; + } + + return __builtin_clz(value); +} + +inline u64 CountLeadingZeroes64(u64 value) { + if (value == 0) { + return 64; + } + + return __builtin_clzll(value); +} +#endif +} // namespace Common |