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/*
Copyright (c) 2009 Nick Clifton <nickc@redhat.com>
*/
.file "strcat.S"
.section .text
.global _strcat
.type _strcat,@function
_strcat:
;; On entry: r1 => Destination
;; r2 => Source
#ifdef __RX_DISALLOW_STRING_INSNS__
mov r1, r4 ; Save a copy of the dest pointer.
1: mov.b [r4+], r5 ; Find the NUL byte at the end of R4.
cmp #0, r5
bne 1b
sub #1, r4 ; Move R4 back to point at the NUL byte.
2: mov.b [r2+], r5 ; Copy bytes from R2 to R4 until we reach a NUL byte.
mov.b r5, [r4+]
cmp #0, r5
bne 2b
rts
#else
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
#endif
.size _strcat, . - _strcat
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