cosmopolitan/libc/intrin/bsr.h
Justine Tunney 6f7d0cb1c3
Pay off more technical debt
This makes breaking changes to add underscores to many non-standard
function names provided by the c library. MODE=tiny is now tinier and
we now use smaller locks that are better for tiny apps in this mode.
Some headers have been renamed to be in the same folder as the build
package, so it'll be easier to know which build dependency is needed.
Certain old misguided interfaces have been removed. Intel intrinsics
headers are now listed in libc/isystem (but not in the amalgamation)
to help further improve open source compatibility. Header complexity
has also been reduced. Lastly, more shell scripts are now available.
2022-09-12 23:36:56 -07:00

29 lines
1.2 KiB
C

#ifndef COSMOPOLITAN_LIBC_NEXGEN32E_BSR_H_
#define COSMOPOLITAN_LIBC_NEXGEN32E_BSR_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
int _bsr(int) pureconst;
int _bsrl(long) pureconst;
int _bsrll(long long) pureconst;
#if defined(__GNUC__) && defined(__x86_64__) && !defined(__STRICT_ANSI__)
int _bsr128(uint128_t) pureconst;
#define _bsr(u) \
({ \
unsigned BiTs; \
asm("bsr\t%0,%0" : "=r"(BiTs) : "0"((unsigned)(u)) : "cc"); \
BiTs; \
})
#define _bsrl(u) \
({ \
unsigned long BiTs; \
asm("bsr\t%0,%0" : "=r"(BiTs) : "0"((unsigned long)(u)) : "cc"); \
(unsigned)BiTs; \
})
#define _bsrll(u) _bsrl(u)
#endif
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_NEXGEN32E_BSR_H_ */