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[dxvk] Implement 64-bit tzcnt

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Philip Rebohle 2022-06-15 16:36:47 +02:00
parent 038ee0416d
commit 16eba45987
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GPG Key ID: C8CC613427A31C99
1 changed files with 28 additions and 0 deletions
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28
src/util/util_bit.h
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@ -77,6 +77,34 @@ namespace dxvk::bit {
#endif
}
inline uint32_t tzcnt(uint64_t n) {
#if defined(_M_X64) && defined(_MSC_VER) && !defined(__clang__)
return _tzcnt_u64(n);
#elif defined(__x86_64__) && defined(__BMI__)
return __tzcnt_u64(n);
#elif defined(__x86_64__) && defined(__GNUC__) || defined(__clang__)
uint64_t res;
uint64_t tmp;
asm (
"mov $64, %1;"
"bsf %2, %0;"
"cmovz %1, %0;"
: "=&r" (res), "=&r" (tmp)
: "r" (n));
return res;
#else
uint32_t r = 63;
n &= -n;
r -= (n & 0x00000000FFFFFFFFull) ? 32 : 0;
r -= (n & 0x0000FFFF0000FFFFull) ? 16 : 0;
r -= (n & 0x00FF00FF00FF00FFull) ? 8 : 0;
r -= (n & 0x0F0F0F0F0F0F0F0Full) ? 4 : 0;
r -= (n & 0x3333333333333333ull) ? 2 : 0;
r -= (n & 0x5555555555555555ull) ? 1 : 0;
return n != 0 ? r : 64;
#endif
}
inline uint32_t bsf(uint32_t n) {
#if defined(_MSC_VER) && !defined(__clang__)
unsigned long index;