libc/newlib/libc/machine/rx/memchr.S

14 lines
455 B
ArmAsm

.file "memchr.S"
.section .text
.global _memchr
.type _memchr,@function
_memchr:
cmp #0, r3 ; If r3 is 0 suntil.b will do nothing and not set any flags...
stz #1, r1 ; ...so store 1 into r1. It will be decremented by the SUB later.
suntil.b ; Search until *r1 == r2 or r3 bytes have been examined.
stnz #1, r1 ; If no match was found return NULL.
sub #1, r1 ; suntil.b leaves r1 pointing at the address *after* the match.
rts