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review.shift-gmbh.com / SHIFTPHONES / mainline / linux / a254a9da455c171441ab3a76ed8f5d1e9412e15f / . / arch / x86 / math-emu / round_Xsig.S
blob: 126c40473badb2d8139717fbea8d774390fd3a69 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +0100[diff] [blame]1/* SPDX-License-Identifier: GPL-2.0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]2/*---------------------------------------------------------------------------+
3 | round_Xsig.S |
4 | |
5 | Copyright (C) 1992,1993,1994,1995 |
6 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
7 | Australia. E-mail billm@jacobi.maths.monash.edu.au |
8 | |
9 | Normalize and round a 12 byte quantity. |
10 | Call from C as: |
11 | int round_Xsig(Xsig *n) |
12 | |
13 | Normalize a 12 byte quantity. |
14 | Call from C as: |
15 | int norm_Xsig(Xsig *n) |
16 | |
17 | Each function returns the size of the shift (nr of bits). |
18 | |
19 +---------------------------------------------------------------------------*/
20 .file "round_Xsig.S"
21
22#include "fpu_emu.h"
23
24
25.text
Jiri Slaby6d685e52019-10-11 13:51:07 +0200[diff] [blame]26SYM_FUNC_START(round_Xsig)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]27 pushl %ebp
28 movl %esp,%ebp
29 pushl %ebx /* Reserve some space */
30 pushl %ebx
31 pushl %esi
32
33 movl PARAM1,%esi
34
35 movl 8(%esi),%edx
36 movl 4(%esi),%ebx
37 movl (%esi),%eax
38
39 movl $0,-4(%ebp)
40
41 orl %edx,%edx /* ms bits */
42 js L_round /* Already normalized */
43 jnz L_shift_1 /* Shift left 1 - 31 bits */
44
45 movl %ebx,%edx
46 movl %eax,%ebx
47 xorl %eax,%eax
48 movl $-32,-4(%ebp)
49
50/* We need to shift left by 1 - 31 bits */
51L_shift_1:
52 bsrl %edx,%ecx /* get the required shift in %ecx */
53 subl $31,%ecx
54 negl %ecx
55 subl %ecx,-4(%ebp)
56 shld %cl,%ebx,%edx
57 shld %cl,%eax,%ebx
58 shl %cl,%eax
59
60L_round:
61 testl $0x80000000,%eax
62 jz L_exit
63
64 addl $1,%ebx
65 adcl $0,%edx
66 jnz L_exit
67
68 movl $0x80000000,%edx
69 incl -4(%ebp)
70
71L_exit:
72 movl %edx,8(%esi)
73 movl %ebx,4(%esi)
74 movl %eax,(%esi)
75
76 movl -4(%ebp),%eax
77
78 popl %esi
79 popl %ebx
80 leave
Peter Zijlstraf94909c2021-12-04 14:43:40 +0100[diff] [blame]81 RET
Jiri Slaby6d685e52019-10-11 13:51:07 +0200[diff] [blame]82SYM_FUNC_END(round_Xsig)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]83
84
85
Jiri Slaby6d685e52019-10-11 13:51:07 +0200[diff] [blame]86SYM_FUNC_START(norm_Xsig)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]87 pushl %ebp
88 movl %esp,%ebp
89 pushl %ebx /* Reserve some space */
90 pushl %ebx
91 pushl %esi
92
93 movl PARAM1,%esi
94
95 movl 8(%esi),%edx
96 movl 4(%esi),%ebx
97 movl (%esi),%eax
98
99 movl $0,-4(%ebp)
100
101 orl %edx,%edx /* ms bits */
102 js L_n_exit /* Already normalized */
103 jnz L_n_shift_1 /* Shift left 1 - 31 bits */
104
105 movl %ebx,%edx
106 movl %eax,%ebx
107 xorl %eax,%eax
108 movl $-32,-4(%ebp)
109
110 orl %edx,%edx /* ms bits */
111 js L_n_exit /* Normalized now */
112 jnz L_n_shift_1 /* Shift left 1 - 31 bits */
113
114 movl %ebx,%edx
115 movl %eax,%ebx
116 xorl %eax,%eax
117 addl $-32,-4(%ebp)
118 jmp L_n_exit /* Might not be normalized,
119 but shift no more. */
120
121/* We need to shift left by 1 - 31 bits */
122L_n_shift_1:
123 bsrl %edx,%ecx /* get the required shift in %ecx */
124 subl $31,%ecx
125 negl %ecx
126 subl %ecx,-4(%ebp)
127 shld %cl,%ebx,%edx
128 shld %cl,%eax,%ebx
129 shl %cl,%eax
130
131L_n_exit:
132 movl %edx,8(%esi)
133 movl %ebx,4(%esi)
134 movl %eax,(%esi)
135
136 movl -4(%ebp),%eax
137
138 popl %esi
139 popl %ebx
140 leave
Peter Zijlstraf94909c2021-12-04 14:43:40 +0100[diff] [blame]141 RET
Jiri Slaby6d685e52019-10-11 13:51:07 +0200[diff] [blame]142SYM_FUNC_END(norm_Xsig)