| #ifndef X86_BUILTIN_CTZ_H |
| #define X86_BUILTIN_CTZ_H |
| |
| #if defined(_MSC_VER) && !defined(__clang__) |
| #if defined(_M_IX86) || defined(_M_AMD64) || defined(_M_IA64) || defined(_M_ARM) || defined(_M_ARM64) |
| |
| #include <intrin.h> |
| #ifdef X86_FEATURES |
| # include "arch/x86/x86.h" |
| #endif |
| |
| /* This is not a general purpose replacement for __builtin_ctz. The function expects that value is != 0 |
| * Because of that assumption trailing_zero is not initialized and the return value of _BitScanForward is not checked |
| */ |
| static __forceinline unsigned long __builtin_ctz(uint32_t value) { |
| #ifdef X86_FEATURES |
| if (x86_cpu_has_tzcnt) |
| return _tzcnt_u32(value); |
| #endif |
| unsigned long trailing_zero; |
| _BitScanForward(&trailing_zero, value); |
| return trailing_zero; |
| } |
| #define HAVE_BUILTIN_CTZ |
| |
| #ifdef _M_AMD64 |
| /* This is not a general purpose replacement for __builtin_ctzll. The function expects that value is != 0 |
| * Because of that assumption trailing_zero is not initialized and the return value of _BitScanForward64 is not checked |
| */ |
| static __forceinline unsigned long long __builtin_ctzll(uint64_t value) { |
| #ifdef X86_FEATURES |
| if (x86_cpu_has_tzcnt) |
| return _tzcnt_u64(value); |
| #endif |
| unsigned long trailing_zero; |
| _BitScanForward64(&trailing_zero, value); |
| return trailing_zero; |
| } |
| #define HAVE_BUILTIN_CTZLL |
| #endif |
| |
| #endif |
| #endif |
| #endif |
