cosmopolitan/libc/intrin/repstosb.h
Justine Tunney c776a32f75
Replace COSMO define with _COSMO_SOURCE
This change might cause ABI breakages for /opt/cosmos. It's needed to
help us better conform to header declaration practices.
2023-08-13 20:55:04 -07:00

27 lines
1,012 B
C

#ifndef COSMOPOLITAN_LIBC_INTRIN_REPSTOSB_H_
#define COSMOPOLITAN_LIBC_INTRIN_REPSTOSB_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
#ifdef _COSMO_SOURCE
forceinline void *repstosb(void *dest, unsigned char al, size_t cx) {
unsigned char *di = (unsigned char *)dest;
while (cx) *di++ = al, cx--;
return di;
}
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
#define repstosb(DI, AL, CX) \
({ \
void *Di = (DI); \
size_t Cx = (CX); \
unsigned char Al = (AL); \
asm("rep stosb %b5,(%0)" \
: "=D"(Di), "=c"(Cx), "=m"(*(char(*)[Cx])Di) \
: "0"(Di), "1"(Cx), "a"(Al)); \
Di; \
})
#endif
#endif /* _COSMO_SOURCE */
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_INTRIN_REPSTOSB_H_ */