forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 4
/
Copy pathround_Xsig.S
142 lines (113 loc) · 3.33 KB
/
round_Xsig.S
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
/* SPDX-License-Identifier: GPL-2.0 */
/*---------------------------------------------------------------------------+
| round_Xsig.S |
| |
| Copyright (C) 1992,1993,1994,1995 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail [email protected] |
| |
| Normalize and round a 12 byte quantity. |
| Call from C as: |
| int round_Xsig(Xsig *n) |
| |
| Normalize a 12 byte quantity. |
| Call from C as: |
| int norm_Xsig(Xsig *n) |
| |
| Each function returns the size of the shift (nr of bits). |
| |
+---------------------------------------------------------------------------*/
.file "round_Xsig.S"
#include "fpu_emu.h"
.text
SYM_FUNC_START(round_Xsig)
pushl %ebp
movl %esp,%ebp
pushl %ebx /* Reserve some space */
pushl %ebx
pushl %esi
movl PARAM1,%esi
movl 8(%esi),%edx
movl 4(%esi),%ebx
movl (%esi),%eax
movl $0,-4(%ebp)
orl %edx,%edx /* ms bits */
js L_round /* Already normalized */
jnz L_shift_1 /* Shift left 1 - 31 bits */
movl %ebx,%edx
movl %eax,%ebx
xorl %eax,%eax
movl $-32,-4(%ebp)
/* We need to shift left by 1 - 31 bits */
L_shift_1:
bsrl %edx,%ecx /* get the required shift in %ecx */
subl $31,%ecx
negl %ecx
subl %ecx,-4(%ebp)
shld %cl,%ebx,%edx
shld %cl,%eax,%ebx
shl %cl,%eax
L_round:
testl $0x80000000,%eax
jz L_exit
addl $1,%ebx
adcl $0,%edx
jnz L_exit
movl $0x80000000,%edx
incl -4(%ebp)
L_exit:
movl %edx,8(%esi)
movl %ebx,4(%esi)
movl %eax,(%esi)
movl -4(%ebp),%eax
popl %esi
popl %ebx
leave
RET
SYM_FUNC_END(round_Xsig)
SYM_FUNC_START(norm_Xsig)
pushl %ebp
movl %esp,%ebp
pushl %ebx /* Reserve some space */
pushl %ebx
pushl %esi
movl PARAM1,%esi
movl 8(%esi),%edx
movl 4(%esi),%ebx
movl (%esi),%eax
movl $0,-4(%ebp)
orl %edx,%edx /* ms bits */
js L_n_exit /* Already normalized */
jnz L_n_shift_1 /* Shift left 1 - 31 bits */
movl %ebx,%edx
movl %eax,%ebx
xorl %eax,%eax
movl $-32,-4(%ebp)
orl %edx,%edx /* ms bits */
js L_n_exit /* Normalized now */
jnz L_n_shift_1 /* Shift left 1 - 31 bits */
movl %ebx,%edx
movl %eax,%ebx
xorl %eax,%eax
addl $-32,-4(%ebp)
jmp L_n_exit /* Might not be normalized,
but shift no more. */
/* We need to shift left by 1 - 31 bits */
L_n_shift_1:
bsrl %edx,%ecx /* get the required shift in %ecx */
subl $31,%ecx
negl %ecx
subl %ecx,-4(%ebp)
shld %cl,%ebx,%edx
shld %cl,%eax,%ebx
shl %cl,%eax
L_n_exit:
movl %edx,8(%esi)
movl %ebx,4(%esi)
movl %eax,(%esi)
movl -4(%ebp),%eax
popl %esi
popl %ebx
leave
RET
SYM_FUNC_END(norm_Xsig)