Blame jemalloc/include/msvc_compat/strings.h

Packit 345191
#ifndef strings_h
Packit 345191
#define strings_h
Packit 345191
Packit 345191
/* MSVC doesn't define ffs/ffsl. This dummy strings.h header is provided
Packit 345191
 * for both */
Packit 345191
#ifdef _MSC_VER
Packit 345191
#  include <intrin.h>
Packit 345191
#  pragma intrinsic(_BitScanForward)
Packit 345191
static __forceinline int ffsl(long x) {
Packit 345191
	unsigned long i;
Packit 345191
Packit 345191
	if (_BitScanForward(&i, x)) {
Packit 345191
		return i + 1;
Packit 345191
	}
Packit 345191
	return 0;
Packit 345191
}
Packit 345191
Packit 345191
static __forceinline int ffs(int x) {
Packit 345191
	return ffsl(x);
Packit 345191
}
Packit 345191
Packit 345191
#  ifdef  _M_X64
Packit 345191
#    pragma intrinsic(_BitScanForward64)
Packit 345191
#  endif
Packit 345191
Packit 345191
static __forceinline int ffsll(unsigned __int64 x) {
Packit 345191
	unsigned long i;
Packit 345191
#ifdef  _M_X64
Packit 345191
	if (_BitScanForward64(&i, x)) {
Packit 345191
		return i + 1;
Packit 345191
	}
Packit 345191
	return 0;
Packit 345191
#else
Packit 345191
// Fallback for 32-bit build where 64-bit version not available
Packit 345191
// assuming little endian
Packit 345191
	union {
Packit 345191
		unsigned __int64 ll;
Packit 345191
		unsigned   long l[2];
Packit 345191
	} s;
Packit 345191
Packit 345191
	s.ll = x;
Packit 345191
Packit 345191
	if (_BitScanForward(&i, s.l[0])) {
Packit 345191
		return i + 1;
Packit 345191
	} else if(_BitScanForward(&i, s.l[1])) {
Packit 345191
		return i + 33;
Packit 345191
	}
Packit 345191
	return 0;
Packit 345191
#endif
Packit 345191
}
Packit 345191
Packit 345191
#else
Packit 345191
#  define ffsll(x) __builtin_ffsll(x)
Packit 345191
#  define ffsl(x) __builtin_ffsl(x)
Packit 345191
#  define ffs(x) __builtin_ffs(x)
Packit 345191
#endif
Packit 345191
Packit 345191
#endif /* strings_h */