33 lines
706 B
ArmAsm
33 lines
706 B
ArmAsm
! strrchr() Author: Kees J. Bot
|
|
! 27 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
|
|
_strrchr:
|
|
push bp
|
|
mov bp, sp
|
|
push di
|
|
mov di, 4(bp) ! di = string
|
|
mov cx, #-1
|
|
xorb al, al
|
|
cld
|
|
repne scasb ! Look for the end of the string
|
|
not cx ! -1 - cx = Length of the string + null
|
|
dec di ! Put di back on the zero byte
|
|
movb al, 6(bp) ! The character to look for
|
|
std ! Downwards search
|
|
repne scasb
|
|
cld ! Direction bit back to default
|
|
jne failure
|
|
lea ax, 1(di) ! Found it
|
|
pop di
|
|
pop bp
|
|
ret
|
|
failure:xor ax, ax ! Not there
|
|
pop di
|
|
pop bp
|
|
ret
|