mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-28 05:51:04 +00:00
23 lines
670 B
ArmAsm
23 lines
670 B
ArmAsm
.file "strcat.S"
|
|
|
|
.section .text
|
|
.global _strcat
|
|
.type _strcat,@function
|
|
_strcat:
|
|
;; On entry: r1 => Destination
|
|
;; r2 => Source
|
|
mov r1, r4 ; Save a copy of the dest pointer.
|
|
mov r2, r5 ; Save a copy of the source pointer.
|
|
|
|
mov #0, r2 ; Search for the NUL byte.
|
|
mov #-1, r3 ; Limit on the number of bytes examined.
|
|
suntil.b ; Find the end of the destination string.
|
|
sub #1, r1 ; suntil.b leaves r1 pointing to the byte beyond the match.
|
|
|
|
mov #-1, r3 ; Set a limit on the number of bytes copied.
|
|
mov r5, r2 ; Restore the source pointer.
|
|
smovu ; Copy source to destination
|
|
|
|
mov r4, r1 ; Return the original dest pointer.
|
|
rts
|