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1/* SPDX-License-Identifier: GPL-2.0 */
2 .file "reg_u_mul.S"
3/*---------------------------------------------------------------------------+
4 | reg_u_mul.S |
5 | |
6 | Core multiplication routine |
7 | |
8 | Copyright (C) 1992,1993,1995,1997 |
9 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
10 | E-mail billm@suburbia.net |
11 | |
12 | |
13 +---------------------------------------------------------------------------*/
14
15/*---------------------------------------------------------------------------+
16 | Basic multiplication routine. |
17 | Does not check the resulting exponent for overflow/underflow |
18 | |
19 | FPU_u_mul(FPU_REG *a, FPU_REG *b, FPU_REG *c, unsigned int cw); |
20 | |
21 | Internal working is at approx 128 bits. |
22 | Result is rounded to nearest 53 or 64 bits, using "nearest or even". |
23 +---------------------------------------------------------------------------*/
24
25#include "exception.h"
26#include "fpu_emu.h"
27#include "control_w.h"
28
29
30
31#ifndef NON_REENTRANT_FPU
32/* Local storage on the stack: */
33#define FPU_accum_0 -4(%ebp) /* ms word */
34#define FPU_accum_1 -8(%ebp)
35
36#else
37/* Local storage in a static area: */
38.data
39 .align 4,0
40FPU_accum_0:
41 .long 0
42FPU_accum_1:
43 .long 0
44#endif /* NON_REENTRANT_FPU */
45
46
47.text
48SYM_FUNC_START(FPU_u_mul)
49 pushl %ebp
50 movl %esp,%ebp
51#ifndef NON_REENTRANT_FPU
52 subl $8,%esp
53#endif /* NON_REENTRANT_FPU */
54
55 pushl %esi
56 pushl %edi
57 pushl %ebx
58
59 movl PARAM1,%esi
60 movl PARAM2,%edi
61
62#ifdef PARANOID
63 testl $0x80000000,SIGH(%esi)
64 jz L_bugged
65 testl $0x80000000,SIGH(%edi)
66 jz L_bugged
67#endif /* PARANOID */
68
69 xorl %ecx,%ecx
70 xorl %ebx,%ebx
71
72 movl SIGL(%esi),%eax
73 mull SIGL(%edi)
74 movl %eax,FPU_accum_0
75 movl %edx,FPU_accum_1
76
77 movl SIGL(%esi),%eax
78 mull SIGH(%edi)
79 addl %eax,FPU_accum_1
80 adcl %edx,%ebx
81/* adcl $0,%ecx // overflow here is not possible */
82
83 movl SIGH(%esi),%eax
84 mull SIGL(%edi)
85 addl %eax,FPU_accum_1
86 adcl %edx,%ebx
87 adcl $0,%ecx
88
89 movl SIGH(%esi),%eax
90 mull SIGH(%edi)
91 addl %eax,%ebx
92 adcl %edx,%ecx
93
94 /* Get the sum of the exponents. */
95 movl PARAM6,%eax
96 subl EXP_BIAS-1,%eax
97
98 /* Two denormals can cause an exponent underflow */
99 cmpl EXP_WAY_UNDER,%eax
100 jg Exp_not_underflow
101
102 /* Set to a really low value allow correct handling */
103 movl EXP_WAY_UNDER,%eax
104
105Exp_not_underflow:
106
107/* Have now finished with the sources */
108 movl PARAM3,%edi /* Point to the destination */
109 movw %ax,EXP(%edi)
110
111/* Now make sure that the result is normalized */
112 testl $0x80000000,%ecx
113 jnz LResult_Normalised
114
115 /* Normalize by shifting left one bit */
116 shll $1,FPU_accum_0
117 rcll $1,FPU_accum_1
118 rcll $1,%ebx
119 rcll $1,%ecx
120 decw EXP(%edi)
121
122LResult_Normalised:
123 movl FPU_accum_0,%eax
124 movl FPU_accum_1,%edx
125 orl %eax,%eax
126 jz L_extent_zero
127
128 orl $1,%edx
129
130L_extent_zero:
131 movl %ecx,%eax
132 jmp fpu_reg_round
133
134
135#ifdef PARANOID
136L_bugged:
137 pushl EX_INTERNAL|0x205
138 call EXCEPTION
139 pop %ebx
140 jmp L_exit
141
142L_exit:
143 popl %ebx
144 popl %edi
145 popl %esi
146 leave
147 RET
148#endif /* PARANOID */
149
150SYM_FUNC_END(FPU_u_mul)
1/* SPDX-License-Identifier: GPL-2.0 */
2 .file "reg_u_mul.S"
3/*---------------------------------------------------------------------------+
4 | reg_u_mul.S |
5 | |
6 | Core multiplication routine |
7 | |
8 | Copyright (C) 1992,1993,1995,1997 |
9 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
10 | E-mail billm@suburbia.net |
11 | |
12 | |
13 +---------------------------------------------------------------------------*/
14
15/*---------------------------------------------------------------------------+
16 | Basic multiplication routine. |
17 | Does not check the resulting exponent for overflow/underflow |
18 | |
19 | FPU_u_mul(FPU_REG *a, FPU_REG *b, FPU_REG *c, unsigned int cw); |
20 | |
21 | Internal working is at approx 128 bits. |
22 | Result is rounded to nearest 53 or 64 bits, using "nearest or even". |
23 +---------------------------------------------------------------------------*/
24
25#include "exception.h"
26#include "fpu_emu.h"
27#include "control_w.h"
28
29
30
31#ifndef NON_REENTRANT_FPU
32/* Local storage on the stack: */
33#define FPU_accum_0 -4(%ebp) /* ms word */
34#define FPU_accum_1 -8(%ebp)
35
36#else
37/* Local storage in a static area: */
38.data
39 .align 4,0
40FPU_accum_0:
41 .long 0
42FPU_accum_1:
43 .long 0
44#endif /* NON_REENTRANT_FPU */
45
46
47.text
48SYM_FUNC_START(FPU_u_mul)
49 pushl %ebp
50 movl %esp,%ebp
51#ifndef NON_REENTRANT_FPU
52 subl $8,%esp
53#endif /* NON_REENTRANT_FPU */
54
55 pushl %esi
56 pushl %edi
57 pushl %ebx
58
59 movl PARAM1,%esi
60 movl PARAM2,%edi
61
62#ifdef PARANOID
63 testl $0x80000000,SIGH(%esi)
64 jz L_bugged
65 testl $0x80000000,SIGH(%edi)
66 jz L_bugged
67#endif /* PARANOID */
68
69 xorl %ecx,%ecx
70 xorl %ebx,%ebx
71
72 movl SIGL(%esi),%eax
73 mull SIGL(%edi)
74 movl %eax,FPU_accum_0
75 movl %edx,FPU_accum_1
76
77 movl SIGL(%esi),%eax
78 mull SIGH(%edi)
79 addl %eax,FPU_accum_1
80 adcl %edx,%ebx
81/* adcl $0,%ecx // overflow here is not possible */
82
83 movl SIGH(%esi),%eax
84 mull SIGL(%edi)
85 addl %eax,FPU_accum_1
86 adcl %edx,%ebx
87 adcl $0,%ecx
88
89 movl SIGH(%esi),%eax
90 mull SIGH(%edi)
91 addl %eax,%ebx
92 adcl %edx,%ecx
93
94 /* Get the sum of the exponents. */
95 movl PARAM6,%eax
96 subl EXP_BIAS-1,%eax
97
98 /* Two denormals can cause an exponent underflow */
99 cmpl EXP_WAY_UNDER,%eax
100 jg Exp_not_underflow
101
102 /* Set to a really low value allow correct handling */
103 movl EXP_WAY_UNDER,%eax
104
105Exp_not_underflow:
106
107/* Have now finished with the sources */
108 movl PARAM3,%edi /* Point to the destination */
109 movw %ax,EXP(%edi)
110
111/* Now make sure that the result is normalized */
112 testl $0x80000000,%ecx
113 jnz LResult_Normalised
114
115 /* Normalize by shifting left one bit */
116 shll $1,FPU_accum_0
117 rcll $1,FPU_accum_1
118 rcll $1,%ebx
119 rcll $1,%ecx
120 decw EXP(%edi)
121
122LResult_Normalised:
123 movl FPU_accum_0,%eax
124 movl FPU_accum_1,%edx
125 orl %eax,%eax
126 jz L_extent_zero
127
128 orl $1,%edx
129
130L_extent_zero:
131 movl %ecx,%eax
132 jmp fpu_reg_round
133
134
135#ifdef PARANOID
136L_bugged:
137 pushl EX_INTERNAL|0x205
138 call EXCEPTION
139 pop %ebx
140 jmp L_exit
141
142L_exit:
143 popl %ebx
144 popl %edi
145 popl %esi
146 leave
147 RET
148#endif /* PARANOID */
149
150SYM_FUNC_END(FPU_u_mul)