mirror of
https://github.com/EduApps-CDG/OpenDX
synced 2024-12-30 09:45:37 +01:00
50 lines
999 B
C++
50 lines
999 B
C++
#pragma once
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#ifndef _MSC_VER
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#include <x86intrin.h>
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#else
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#include <intrin.h>
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#endif
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namespace dxvk::bit {
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template<typename T>
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T extract(T value, uint32_t fst, uint32_t lst) {
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return (value >> fst) & ~(~T(0) << (lst - fst + 1));
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}
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template<typename T>
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T popcnt(T value) {
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return value != 0
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? (value & 1) + popcnt(value >> 1)
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: 0;
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}
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inline uint32_t tzcnt(uint32_t n) {
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#if defined(_MSC_VER)
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return _tzcnt_u32(n);
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#elif defined(__BMI__)
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return __tzcnt_u32(n);
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#elif defined(__GNUC__)
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uint32_t res;
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uint32_t tmp;
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asm (
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"mov $32, %1;"
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"bsf %2, %0;"
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"cmovz %1, %0;"
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: "=&r" (res), "=&r" (tmp)
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: "r" (n));
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return res;
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#else
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uint32_t r = 31;
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n &= -n;
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r -= (n & 0x0000FFFF) ? 16 : 0;
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r -= (n & 0x00FF00FF) ? 8 : 0;
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r -= (n & 0x0F0F0F0F) ? 4 : 0;
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r -= (n & 0x33333333) ? 2 : 0;
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r -= (n & 0x55555555) ? 1 : 0;
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return n != 0 ? r : 32;
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#endif
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}
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} |