about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc64/strcpy.S
blob: e57eeb30cf658116c27348859d2f08b75f51da48 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/* Optimized strcpy implementation for PowerPC64.
   Copyright (C) 1997, 1999, 2000, 2002, 2003, 2011 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include <bp-sym.h>
#include <bp-asm.h>

/* See strlen.s for comments on how the end-of-string testing works.  */

/* char * [r3] strcpy (char *dest [r3], const char *src [r4])  */

EALIGN (BP_SYM (strcpy), 4, 0)
	CALL_MCOUNT 2

#define rTMP	r0
#define rRTN	r3	/* incoming DEST arg preserved as result */
/* Note.  The Bounded pointer support in this code is broken.  This code
   was inherited from PPC32 and that support was never completed.  
   Current PPC gcc does not support -fbounds-check or -fbounded-pointers.
   These artifacts are left in the code as a reminder in case we need
   bounded pointer support in the future.  */
#if __BOUNDED_POINTERS__
# define rDEST	r4	/* pointer to previous word in dest */
# define rSRC	r5	/* pointer to previous word in src */
# define rLOW	r11
# define rHIGH	r12
#else
# define rSRC	r4	/* pointer to previous word in src */
# define rDEST	r5	/* pointer to previous word in dest */
#endif
#define rWORD	r6	/* current word from src */
#define rFEFE	r7	/* constant 0xfefefefefefefeff (-0x0101010101010101) */
#define r7F7F	r8	/* constant 0x7f7f7f7f7f7f7f7f */
#define rNEG	r9	/* ~(word in s1 | 0x7f7f7f7f7f7f7f7f) */
#define rALT	r10	/* alternate word from src */

	CHECK_BOUNDS_LOW (rSRC, rLOW, rHIGH)
	CHECK_BOUNDS_LOW (rDEST, rLOW, rHIGH)
	STORE_RETURN_BOUNDS (rLOW, rHIGH)

	dcbt	0,rSRC
	or	rTMP, rSRC, rRTN
	clrldi.	rTMP, rTMP, 61
#if __BOUNDED_POINTERS__
	addi	rDEST, rDEST, -8
#else
	addi	rDEST, rRTN, -8
#endif
	dcbtst	0,rRTN
	bne	L(unaligned)

	lis	rFEFE, -0x101
	lis	r7F7F, 0x7f7f
	ld	rWORD, 0(rSRC)
	addi	rFEFE, rFEFE, -0x101
	addi	r7F7F, r7F7F, 0x7f7f
	sldi	rTMP, rFEFE, 32
	insrdi	r7F7F, r7F7F, 32, 0
	add	rFEFE, rFEFE, rTMP
	b	L(g2)

L(g0):	ldu	rALT, 8(rSRC)
	stdu	rWORD, 8(rDEST)
	add	rTMP, rFEFE, rALT
	nor	rNEG, r7F7F, rALT
	and.	rTMP, rTMP, rNEG
	bne-	L(g1)
	ldu	rWORD, 8(rSRC)
	stdu	rALT, 8(rDEST)
L(g2):	add	rTMP, rFEFE, rWORD
	nor	rNEG, r7F7F, rWORD
	and.	rTMP, rTMP, rNEG
	beq+	L(g0)

	mr	rALT, rWORD
/* We've hit the end of the string.  Do the rest byte-by-byte.  */
L(g1):
	extrdi.	rTMP, rALT, 8, 0
	stb	rTMP, 8(rDEST)
	beqlr-
	extrdi.	rTMP, rALT, 8, 8
	stb	rTMP, 9(rDEST)
	beqlr-
	extrdi.	rTMP, rALT, 8, 16
	stb	rTMP, 10(rDEST)
	beqlr-
	extrdi.	rTMP, rALT, 8, 24
	stb	rTMP, 11(rDEST)
	beqlr-
	extrdi.	rTMP, rALT, 8, 32
	stb	rTMP, 12(rDEST)
	beqlr-
	extrdi.	rTMP, rALT, 8, 40
	stb	rTMP, 13(rDEST)
	beqlr-
	extrdi.	rTMP, rALT, 8, 48
	stb	rTMP, 14(rDEST)
	beqlr-
	stb	rALT, 15(rDEST)
	/* GKM FIXME: check high bound.  */
	blr

/* Oh well.  In this case, we just do a byte-by-byte copy.  */
	.align 4
	nop
L(unaligned):
	lbz	rWORD, 0(rSRC)
	addi	rDEST, rRTN, -1
	cmpwi	rWORD, 0
	beq-	L(u2)

L(u0):	lbzu	rALT, 1(rSRC)
	stbu	rWORD, 1(rDEST)
	cmpwi	rALT, 0
	beq-	L(u1)
	nop		/* Let 601 load start of loop.  */
	lbzu	rWORD, 1(rSRC)
	stbu	rALT, 1(rDEST)
	cmpwi	rWORD, 0
	bne+	L(u0)
L(u2):	stb	rWORD, 1(rDEST)
	/* GKM FIXME: check high bound.  */
	blr
L(u1):	stb	rALT, 1(rDEST)
	/* GKM FIXME: check high bound.  */
	blr

END (BP_SYM (strcpy))
libc_hidden_builtin_def (strcpy)