1#ifndef X86_BUILTIN_CTZ_H
2#define X86_BUILTIN_CTZ_H
3
4#if defined(_MSC_VER) && !defined(__clang__)
5#if defined(_M_IX86) || defined(_M_AMD64) || defined(_M_IA64) || defined(_M_ARM) || defined(_M_ARM64)
6
7#include <intrin.h>
8#ifdef X86_FEATURES
9# include "arch/x86/x86.h"
10#endif
11
12/* This is not a general purpose replacement for __builtin_ctz. The function expects that value is != 0
13 * Because of that assumption trailing_zero is not initialized and the return value of _BitScanForward is not checked
14 */
15static __forceinline unsigned long __builtin_ctz(uint32_t value) {
16#ifdef X86_FEATURES
17 if (x86_cpu_has_tzcnt)
18 return _tzcnt_u32(value);
19#endif
20 unsigned long trailing_zero;
21 _BitScanForward(&trailing_zero, value);
22 return trailing_zero;
23}
24#define HAVE_BUILTIN_CTZ
25
26#ifdef _M_AMD64
27/* This is not a general purpose replacement for __builtin_ctzll. The function expects that value is != 0
28 * Because of that assumption trailing_zero is not initialized and the return value of _BitScanForward64 is not checked
29 */
30static __forceinline unsigned long long __builtin_ctzll(uint64_t value) {
31#ifdef X86_FEATURES
32 if (x86_cpu_has_tzcnt)
33 return _tzcnt_u64(value);
34#endif
35 unsigned long trailing_zero;
36 _BitScanForward64(&trailing_zero, value);
37 return trailing_zero;
38}
39#define HAVE_BUILTIN_CTZLL
40#endif
41
42#endif
43#endif
44#endif
45