xref: /openbmc/linux/arch/powerpc/lib/string.S (revision e23feb16)
1/*
2 * String handling functions for PowerPC.
3 *
4 * Copyright (C) 1996 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#include <asm/processor.h>
12#include <asm/errno.h>
13#include <asm/ppc_asm.h>
14
15	.section __ex_table,"a"
16	PPC_LONG_ALIGN
17	.text
18
19_GLOBAL(strcpy)
20	addi	r5,r3,-1
21	addi	r4,r4,-1
221:	lbzu	r0,1(r4)
23	cmpwi	0,r0,0
24	stbu	r0,1(r5)
25	bne	1b
26	blr
27
28/* This clears out any unused part of the destination buffer,
29   just as the libc version does.  -- paulus */
30_GLOBAL(strncpy)
31	PPC_LCMPI 0,r5,0
32	beqlr
33	mtctr	r5
34	addi	r6,r3,-1
35	addi	r4,r4,-1
361:	lbzu	r0,1(r4)
37	cmpwi	0,r0,0
38	stbu	r0,1(r6)
39	bdnzf	2,1b		/* dec ctr, branch if ctr != 0 && !cr0.eq */
40	bnelr			/* if we didn't hit a null char, we're done */
41	mfctr	r5
42	PPC_LCMPI 0,r5,0	/* any space left in destination buffer? */
43	beqlr			/* we know r0 == 0 here */
442:	stbu	r0,1(r6)	/* clear it out if so */
45	bdnz	2b
46	blr
47
48_GLOBAL(strcat)
49	addi	r5,r3,-1
50	addi	r4,r4,-1
511:	lbzu	r0,1(r5)
52	cmpwi	0,r0,0
53	bne	1b
54	addi	r5,r5,-1
551:	lbzu	r0,1(r4)
56	cmpwi	0,r0,0
57	stbu	r0,1(r5)
58	bne	1b
59	blr
60
61_GLOBAL(strcmp)
62	addi	r5,r3,-1
63	addi	r4,r4,-1
641:	lbzu	r3,1(r5)
65	cmpwi	1,r3,0
66	lbzu	r0,1(r4)
67	subf.	r3,r0,r3
68	beqlr	1
69	beq	1b
70	blr
71
72_GLOBAL(strncmp)
73	PPC_LCMPI 0,r5,0
74	beq-	2f
75	mtctr	r5
76	addi	r5,r3,-1
77	addi	r4,r4,-1
781:	lbzu	r3,1(r5)
79	cmpwi	1,r3,0
80	lbzu	r0,1(r4)
81	subf.	r3,r0,r3
82	beqlr	1
83	bdnzt	eq,1b
84	blr
852:	li	r3,0
86	blr
87
88_GLOBAL(strlen)
89	addi	r4,r3,-1
901:	lbzu	r0,1(r4)
91	cmpwi	0,r0,0
92	bne	1b
93	subf	r3,r3,r4
94	blr
95
96_GLOBAL(memcmp)
97	PPC_LCMPI 0,r5,0
98	beq-	2f
99	mtctr	r5
100	addi	r6,r3,-1
101	addi	r4,r4,-1
1021:	lbzu	r3,1(r6)
103	lbzu	r0,1(r4)
104	subf.	r3,r0,r3
105	bdnzt	2,1b
106	blr
1072:	li	r3,0
108	blr
109
110_GLOBAL(memchr)
111	PPC_LCMPI 0,r5,0
112	beq-	2f
113	mtctr	r5
114	addi	r3,r3,-1
1151:	lbzu	r0,1(r3)
116	cmpw	0,r0,r4
117	bdnzf	2,1b
118	beqlr
1192:	li	r3,0
120	blr
121
122#ifdef CONFIG_PPC32
123_GLOBAL(__clear_user)
124	addi	r6,r3,-4
125	li	r3,0
126	li	r5,0
127	cmplwi	0,r4,4
128	blt	7f
129	/* clear a single word */
13011:	stwu	r5,4(r6)
131	beqlr
132	/* clear word sized chunks */
133	andi.	r0,r6,3
134	add	r4,r0,r4
135	subf	r6,r0,r6
136	srwi	r0,r4,2
137	andi.	r4,r4,3
138	mtctr	r0
139	bdz	7f
1401:	stwu	r5,4(r6)
141	bdnz	1b
142	/* clear byte sized chunks */
1437:	cmpwi	0,r4,0
144	beqlr
145	mtctr	r4
146	addi	r6,r6,3
1478:	stbu	r5,1(r6)
148	bdnz	8b
149	blr
15090:	mr	r3,r4
151	blr
15291:	mfctr	r3
153	slwi	r3,r3,2
154	add	r3,r3,r4
155	blr
15692:	mfctr	r3
157	blr
158
159	.section __ex_table,"a"
160	PPC_LONG	11b,90b
161	PPC_LONG	1b,91b
162	PPC_LONG	8b,92b
163	.text
164#endif
165