about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc64/le/power9/strcpy.S
blob: 603bde1e3989d5c28b2693ebb653f5e1d3431d66 (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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/* Optimized strcpy implementation for PowerPC64/POWER9.
   Copyright (C) 2020-2024 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, see
   <https://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#ifdef USE_AS_STPCPY
# ifndef STPCPY
#   define FUNC_NAME __stpcpy
# else
#   define FUNC_NAME STPCPY
# endif
#else
# ifndef STRCPY
#  define FUNC_NAME strcpy
# else
#  define FUNC_NAME STRCPY
# endif
#endif  /* !USE_AS_STPCPY  */

/* Implements the function

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

   or

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

   if USE_AS_STPCPY is defined.

   The implementation can load bytes past a null terminator, but only
   up to the next 16B boundary, so it never crosses a page.  */

/* Load quadword at addr+offset to vreg, check for null bytes,
   and branch to label if any are found.  */
#define CHECK16(vreg,offset,addr,label) \
	lxv	vreg+32,offset(addr);	\
	vcmpequb. v6,vreg,v18;	\
	bne	cr6,L(label);

.machine power9
ENTRY_TOCLESS (FUNC_NAME, 4)
	CALL_MCOUNT 2

	vspltisb v18,0		/* Zeroes in v18  */
	vspltisb v19,-1 	/* 0xFF bytes in v19  */

	/* Next 16B-aligned address. Prepare address for L(loop).  */
	addi	r5,r4,16
	clrrdi	r5,r5,4
	subf	r8,r4,r5
	add	r11,r3,r8

	/* Align data and fill bytes not loaded with non matching char.  */
	lvx	v0,0,r4
	lvsr	v1,0,r4
	vperm	v0,v19,v0,v1

	vcmpequb. v6,v0,v18	/* 0xff if byte is NULL, 0x00 otherwise  */
	beq	cr6,L(no_null)

	/* There's a null byte.  */
	vctzlsbb r8,v6		/* Number of trailing zeroes  */
	addi	r9,r8,1 	/* Add null byte.  */
	sldi	r10,r9,56	/* stxvl wants size in top 8 bits.  */
	stxvl	32+v0,r3,r10	/* Partial store  */

#ifdef USE_AS_STPCPY
	/* stpcpy returns the dest address plus the size not counting the
	   final '\0'.  */
	add	r3,r3,r8
#endif
	blr

L(no_null):
	sldi	r10,r8,56	/* stxvl wants size in top 8 bits  */
	stxvl	32+v0,r3,r10	/* Partial store  */

	.p2align 4
L(loop):
	CHECK16(v0,0,r5,tail1)
	CHECK16(v1,16,r5,tail2)
	CHECK16(v2,32,r5,tail3)
	CHECK16(v3,48,r5,tail4)
	CHECK16(v4,64,r5,tail5)
	CHECK16(v5,80,r5,tail6)

	stxv	32+v0,0(r11)
	stxv	32+v1,16(r11)
	stxv	32+v2,32(r11)
	stxv	32+v3,48(r11)
	stxv	32+v4,64(r11)
	stxv	32+v5,80(r11)

	addi	r5,r5,96
	addi	r11,r11,96

	b	L(loop)

	.p2align 4
L(tail1):
	vctzlsbb r8,v6		/* Number of trailing zeroes  */
	addi	r9,r8,1		/* Add null terminator  */
	sldi	r9,r9,56	/* stxvl wants size in top 8 bits  */
	stxvl	32+v0,r11,r9	/* Partial store  */
#ifdef USE_AS_STPCPY
	/* stpcpy returns the dest address plus the size not counting the
	   final '\0'.  */
	add	r3,r11,r8
#endif
	blr

	.p2align 4
L(tail2):
	stxv	32+v0,0(r11)
	vctzlsbb r8,v6
	addi	r9,r8,1
	sldi	r9,r9,56
	addi	r11,r11,16
	stxvl	32+v1,r11,r9
#ifdef USE_AS_STPCPY
	add	r3,r11,r8
#endif
	blr

	.p2align 4
L(tail3):
	stxv	32+v0,0(r11)
	stxv	32+v1,16(r11)
	vctzlsbb r8,v6
	addi	r9,r8,1
	sldi	r9,r9,56
	addi	r11,r11,32
	stxvl	32+v2,r11,r9
#ifdef USE_AS_STPCPY
	add	r3,r11,r8
#endif
	blr

	.p2align 4
L(tail4):
	stxv	32+v0,0(r11)
	stxv	32+v1,16(r11)
	stxv	32+v2,32(r11)
	vctzlsbb r8,v6
	addi	r9,r8,1
	sldi	r9,r9,56
	addi	r11,r11,48
	stxvl	32+v3,r11,r9
#ifdef USE_AS_STPCPY
	add	r3,r11,r8
#endif
	blr

	.p2align 4
L(tail5):
	stxv	32+v0,0(r11)
	stxv	32+v1,16(r11)
	stxv	32+v2,32(r11)
	stxv	32+v3,48(r11)
	vctzlsbb r8,v6
	addi	r9,r8,1
	sldi	r9,r9,56
	addi	r11,r11,64
	stxvl	32+v4,r11,r9
#ifdef USE_AS_STPCPY
	add	r3,r11,r8
#endif
	blr

	.p2align 4
L(tail6):
	stxv	32+v0,0(r11)
	stxv	32+v1,16(r11)
	stxv	32+v2,32(r11)
	stxv	32+v3,48(r11)
	stxv	32+v4,64(r11)
	vctzlsbb r8,v6
	addi	r9,r8,1
	sldi	r9,r9,56
	addi	r11,r11,80
	stxvl	32+v5,r11,r9
#ifdef USE_AS_STPCPY
	add	r3,r11,r8
#endif
	blr

END (FUNC_NAME)
#ifndef USE_AS_STPCPY
libc_hidden_builtin_def (strcpy)
#endif