File: memset.S

package info (click to toggle)
glibc 2.19-18+deb8u7
  • links: PTS, VCS
  • area: main
  • in suites: jessie-backports
  • size: 204,748 kB
  • sloc: ansic: 970,427; asm: 241,207; sh: 10,069; makefile: 8,476; cpp: 3,595; perl: 2,077; pascal: 1,839; awk: 1,704; yacc: 317; sed: 73
file content (132 lines) | stat: -rw-r--r-- 3,187 bytes parent folder | download | duplicates (10)
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
/* memset/bzero -- set memory area to CH/0
   Optimized version for x86-64.
   Copyright (C) 2002-2014 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
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

	.text
#if !defined NOT_IN_libc
ENTRY(__bzero)
	movq	%rdi, %rax /* Set return value.  */
	movq	%rsi, %rdx /* Set n.  */
	pxor	%xmm8, %xmm8
	jmp	L(entry_from_bzero)
END(__bzero)
weak_alias (__bzero, bzero)

/* Like memset but takes additional parameter with return value.  */
ENTRY(__memset_tail)
	movq	%rcx, %rax /* Set return value.  */

	movd	%esi, %xmm8
	punpcklbw	%xmm8, %xmm8
	punpcklwd	%xmm8, %xmm8
	pshufd	$0, %xmm8, %xmm8

	jmp	L(entry_from_bzero)
END(__memset_tail)
#endif

#if defined PIC && !defined NOT_IN_libc
ENTRY_CHK (__memset_chk)
	cmpq	%rdx, %rcx
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (__memset_chk)
#endif

ENTRY (memset)
	movd	%esi, %xmm8
	movq	%rdi, %rax
	punpcklbw	%xmm8, %xmm8
	punpcklwd	%xmm8, %xmm8
	pshufd	$0, %xmm8, %xmm8
L(entry_from_bzero):
	cmpq	$64, %rdx
	ja	L(loop_start)
	cmpq	$16, %rdx
	jbe	L(less_16_bytes)
	cmpq	$32, %rdx
	movdqu	%xmm8, (%rdi)
	movdqu	%xmm8, -16(%rdi,%rdx)
	ja	L(between_32_64_bytes)
L(return):
	rep
	ret
	.p2align 4
L(between_32_64_bytes):
	movdqu	%xmm8, 16(%rdi)
	movdqu	%xmm8, -32(%rdi,%rdx)
	ret
	.p2align 4
L(loop_start):
	leaq	64(%rdi), %rcx
	movdqu	%xmm8, (%rdi)
	andq	$-64, %rcx
	movdqu	%xmm8, -16(%rdi,%rdx)
	movdqu	%xmm8, 16(%rdi)
	movdqu	%xmm8, -32(%rdi,%rdx)
	movdqu	%xmm8, 32(%rdi)
	movdqu	%xmm8, -48(%rdi,%rdx)
	movdqu	%xmm8, 48(%rdi)
	movdqu	%xmm8, -64(%rdi,%rdx)
	addq	%rdi, %rdx
	andq	$-64, %rdx
	cmpq	%rdx, %rcx
	je	L(return)
	.p2align 4
L(loop):
	movdqa	%xmm8, (%rcx)
	movdqa	%xmm8, 16(%rcx)
	movdqa	%xmm8, 32(%rcx)
	movdqa	%xmm8, 48(%rcx)
	addq	$64, %rcx
	cmpq	%rcx, %rdx
	jne	L(loop)
	rep
	ret
L(less_16_bytes):
	movq %xmm8, %rcx
	testb	$24, %dl
	jne	L(between8_16bytes)
	testb	$4, %dl
	jne	L(between4_7bytes)
	testb	$1, %dl
	je	L(odd_byte)
	movb	%cl, (%rdi)
L(odd_byte):
	testb	$2, %dl
	je	L(return)
	movw	%cx, -2(%rax,%rdx)
	ret
L(between4_7bytes):
	movl	%ecx, (%rdi)
	movl	%ecx, -4(%rdi,%rdx)
	ret
L(between8_16bytes):
	movq	%rcx, (%rdi)
	movq	%rcx, -8(%rdi,%rdx)
	ret

END (memset)
libc_hidden_builtin_def (memset)

#if defined PIC && !defined NOT_IN_libc && !defined USE_MULTIARCH
strong_alias (__memset_chk, __memset_zero_constant_len_parameter)
	.section .gnu.warning.__memset_zero_constant_len_parameter
	.string "memset used with constant zero length parameter; this could be due to transposed parameters"
#endif