xref: /openbmc/linux/arch/alpha/lib/strcat.S (revision 1c2dd16a)
1/*
2 * arch/alpha/lib/strcat.S
3 * Contributed by Richard Henderson (rth@tamu.edu)
4 *
5 * Append a null-terminated string from SRC to DST.
6 */
7#include <asm/export.h>
8
9	.text
10
11	.align 3
12	.globl strcat
13	.ent strcat
14strcat:
15	.frame $30, 0, $26
16	.prologue 0
17
18	mov	$16, $0		# set up return value
19
20	/* Find the end of the string.  */
21
22	ldq_u   $1, 0($16)	# load first quadword (a0 may be misaligned)
23	lda     $2, -1
24	insqh   $2, $16, $2
25	andnot  $16, 7, $16
26	or      $2, $1, $1
27	cmpbge  $31, $1, $2	# bits set iff byte == 0
28	bne     $2, $found
29
30$loop:	ldq     $1, 8($16)
31	addq    $16, 8, $16
32	cmpbge  $31, $1, $2
33	beq     $2, $loop
34
35$found:	negq    $2, $3		# clear all but least set bit
36	and     $2, $3, $2
37
38	and     $2, 0xf0, $3	# binary search for that set bit
39	and	$2, 0xcc, $4
40	and	$2, 0xaa, $5
41	cmovne	$3, 4, $3
42	cmovne	$4, 2, $4
43	cmovne	$5, 1, $5
44	addq	$3, $4, $3
45	addq	$16, $5, $16
46	addq	$16, $3, $16
47
48	/* Now do the append.  */
49
50	mov	$26, $23
51	br	__stxcpy
52
53	.end strcat
54EXPORT_SYMBOL(strcat);
55