diff options
Diffstat (limited to 'newlib/libc/machine/rx/strncat.S')
| -rw-r--r-- | newlib/libc/machine/rx/strncat.S | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/newlib/libc/machine/rx/strncat.S b/newlib/libc/machine/rx/strncat.S index 3bc6b75ae..ba544a43a 100644 --- a/newlib/libc/machine/rx/strncat.S +++ b/newlib/libc/machine/rx/strncat.S @@ -7,7 +7,27 @@ _strncat: ;; On entry: r1 => Destination ;; r2 => Source ;; r3 => Max number of bytes to copy +#ifdef __RX_DISALLOW_STRING_INSNS__ + cmp #0, r3 ; If max is zero we have nothing to do. + beq 2f + mov r1, r4 ; Leave the desintation pointer intact for the return value. + +1: mov.b [r4+], r5 ; Find the NUL byte at the end of the destination. + cmp #0, r5 + bne 1b + + sub #1, r4 + +3: mov.b [r2+], r5 ; Copy bytes from the source into the destination ... + mov.b r5, [r4+] + cmp #0, r5 ; ... until we reach a NUL byte ... + beq 2f + sub #1, r3 + bne 3b ; ... or we have copied N bytes. + +2: rts +#else mov r1, r4 ; Save a copy of the dest pointer. mov r2, r5 ; Save a copy of the source pointer. mov r3, r14 ; Save a copy of the byte count. @@ -33,3 +53,6 @@ _strncat: 1: mov r4, r1 ; Return the original dest pointer. rts +#endif + .size _strncat, . - _strncat + |