mirror of
https://github.com/obsproject/obs-studio.git
synced 2026-01-26 07:08:34 -05:00
6862de6d14
This change modifies the `ctz32` function to use `_CountTrailingZeros` when `_M_ARM64` is defined, as `_tzcnt_u32` is not available on WOA.
77 lines
1.4 KiB
C
77 lines
1.4 KiB
C
#pragma once
|
|
|
|
#if defined(__GNUC__) || defined(__clang__)
|
|
static inline uint32_t clz32(unsigned long val)
|
|
{
|
|
return __builtin_clz(val);
|
|
}
|
|
|
|
static inline uint32_t ctz32(unsigned long val)
|
|
{
|
|
return __builtin_ctz(val);
|
|
}
|
|
#elif defined(_MSC_VER) && _MSC_VER >= 1400
|
|
static inline uint32_t clz32(unsigned long val)
|
|
{
|
|
/* __lzcnt() / _lzcnt_u32() do not work correctly on older Intel CPUs,
|
|
* so use BSR instead for better compatibility. */
|
|
uint32_t zeros = 0;
|
|
_BitScanReverse(&zeros, val);
|
|
return 31 - zeros;
|
|
}
|
|
|
|
static inline uint32_t ctz32(unsigned long val)
|
|
{
|
|
#if defined(_M_ARM64)
|
|
return _CountTrailingZeros(val);
|
|
#else
|
|
return _tzcnt_u32(val);
|
|
#endif
|
|
}
|
|
#else
|
|
static uint32_t popcnt(uint32_t x)
|
|
{
|
|
x -= ((x >> 1) & 0x55555555);
|
|
x = (((x >> 2) & 0x33333333) + (x & 0x33333333));
|
|
x = (((x >> 4) + x) & 0x0f0f0f0f);
|
|
x += (x >> 8);
|
|
x += (x >> 16);
|
|
return x & 0x0000003f;
|
|
}
|
|
|
|
static uint32_t clz32(uint32_t x)
|
|
{
|
|
x |= (x >> 1);
|
|
x |= (x >> 2);
|
|
x |= (x >> 4);
|
|
x |= (x >> 8);
|
|
x |= (x >> 16);
|
|
return 32 - popcnt(x);
|
|
}
|
|
|
|
static uint32_t ctz32(uint32_t x)
|
|
{
|
|
return popcnt((x & -x) - 1);
|
|
}
|
|
#endif
|
|
|
|
static inline uint32_t min_u32(uint32_t a, uint32_t b)
|
|
{
|
|
return (a < b) ? a : b;
|
|
}
|
|
|
|
static inline uint16_t min_u16(uint16_t a, uint16_t b)
|
|
{
|
|
return (a < b) ? a : b;
|
|
}
|
|
|
|
static inline int32_t min_i32(int32_t a, int32_t b)
|
|
{
|
|
return (a < b) ? a : b;
|
|
}
|
|
|
|
static inline uint8_t max_u8(uint8_t a, uint8_t b)
|
|
{
|
|
return (a > b) ? a : b;
|
|
}
|