minix/lib/i386/string/strrchr.s
2009-11-09 10:26:00 +00:00

36 lines
736 B
ArmAsm

! strrchr() Author: Kees J. Bot
! 2 Jan 1994
.sect .text; .sect .rom; .sect .data; .sect .bss
! char *strrchr(const char *s, int c)
! Look for the last occurrence a character in a string.
!
.sect .text
.define _strrchr
.align 16
_strrchr:
push ebp
mov ebp, esp
push edi
mov edi, 8(ebp) ! edi = string
mov ecx, -1
xorb al, al
cld
repne
scasb ! Look for the end of the string
not ecx ! -1 - ecx = Length of the string + null
dec edi ! Put edi back on the zero byte
movb al, 12(ebp) ! The character to look for
std ! Downwards search
repne
scasb
cld ! Direction bit back to default
jne failure
lea eax, 1(edi) ! Found it
pop edi
pop ebp
ret
failure:xor eax, eax ! Not there
pop edi
pop ebp
ret