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
|
/* i80586 sub_n -- Sub two limb vectors of the same length > 0 and store
* sum in a third limb vector.
*
* Copyright (C) 1992, 1994, 1995, 1998,
* 2001 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* Note: This code is heavily based on the GNU MP Library.
* Actually it's the same code with only minor changes in the
* way the data is stored; this is to support the abstraction
* of an optional secure memory allocation which may be used
* to avoid revealing of sensitive data due to paging etc.
* The GNU MP Library itself is published under the LGPL;
* however I decided to publish this code under the plain GPL.
*/
#include "sysdep.h"
#include "asm-syntax.h"
/*******************
* mpi_limb_t
* mpihelp_sub_n( mpi_ptr_t res_ptr, (sp + 4)
* mpi_ptr_t s1_ptr, (sp + 8)
* mpi_ptr_t s2_ptr, (sp + 12)
* mpi_size_t size) (sp + 16)
*/
.text
ALIGN (3)
.globl C_SYMBOL_NAME(mpihelp_sub_n)
C_SYMBOL_NAME(mpihelp_sub_n:)
pushl %edi
pushl %esi
pushl %ebx
pushl %ebp
movl 20(%esp),%edi /* res_ptr */
movl 24(%esp),%esi /* s1_ptr */
movl 28(%esp),%ebp /* s2_ptr */
movl 32(%esp),%ecx /* size */
movl (%ebp),%ebx
decl %ecx
movl %ecx,%edx
shrl $3,%ecx
andl $7,%edx
testl %ecx,%ecx /* zero carry flag */
jz Lend
pushl %edx
ALIGN (3)
Loop: movl 28(%edi),%eax /* fetch destination cache line */
leal 32(%edi),%edi
L1: movl (%esi),%eax
movl 4(%esi),%edx
sbbl %ebx,%eax
movl 4(%ebp),%ebx
sbbl %ebx,%edx
movl 8(%ebp),%ebx
movl %eax,-32(%edi)
movl %edx,-28(%edi)
L2: movl 8(%esi),%eax
movl 12(%esi),%edx
sbbl %ebx,%eax
movl 12(%ebp),%ebx
sbbl %ebx,%edx
movl 16(%ebp),%ebx
movl %eax,-24(%edi)
movl %edx,-20(%edi)
L3: movl 16(%esi),%eax
movl 20(%esi),%edx
sbbl %ebx,%eax
movl 20(%ebp),%ebx
sbbl %ebx,%edx
movl 24(%ebp),%ebx
movl %eax,-16(%edi)
movl %edx,-12(%edi)
L4: movl 24(%esi),%eax
movl 28(%esi),%edx
sbbl %ebx,%eax
movl 28(%ebp),%ebx
sbbl %ebx,%edx
movl 32(%ebp),%ebx
movl %eax,-8(%edi)
movl %edx,-4(%edi)
leal 32(%esi),%esi
leal 32(%ebp),%ebp
decl %ecx
jnz Loop
popl %edx
Lend:
decl %edx /* test %edx w/o clobbering carry */
js Lend2
incl %edx
Loop2:
leal 4(%edi),%edi
movl (%esi),%eax
sbbl %ebx,%eax
movl 4(%ebp),%ebx
movl %eax,-4(%edi)
leal 4(%esi),%esi
leal 4(%ebp),%ebp
decl %edx
jnz Loop2
Lend2:
movl (%esi),%eax
sbbl %ebx,%eax
movl %eax,(%edi)
sbbl %eax,%eax
negl %eax
popl %ebp
popl %ebx
popl %esi
popl %edi
ret
|
