1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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 |
26 | SYM_FUNC_START(round_Xsig) |
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 */ |
51 | L_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 | |
60 | L_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 | |
71 | L_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 |
81 | RET |
82 | SYM_FUNC_END(round_Xsig) |
83 | |
84 | |
85 | |
86 | SYM_FUNC_START(norm_Xsig) |
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 */ |
122 | L_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 | |
131 | L_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 |
141 | RET |
142 | SYM_FUNC_END(norm_Xsig) |
143 | |