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1/*---------------------------------------------------------------------------+
2 | fpu_etc.c |
3 | |
4 | Implement a few FPU instructions. |
5 | |
6 | Copyright (C) 1992,1993,1994,1997 |
7 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
8 | Australia. E-mail billm@suburbia.net |
9 | |
10 | |
11 +---------------------------------------------------------------------------*/
12
13#include "fpu_system.h"
14#include "exception.h"
15#include "fpu_emu.h"
16#include "status_w.h"
17#include "reg_constant.h"
18
19static void fchs(FPU_REG *st0_ptr, u_char st0tag)
20{
21 if (st0tag ^ TAG_Empty) {
22 signbyte(st0_ptr) ^= SIGN_NEG;
23 clear_C1();
24 } else
25 FPU_stack_underflow();
26}
27
28static void fabs(FPU_REG *st0_ptr, u_char st0tag)
29{
30 if (st0tag ^ TAG_Empty) {
31 setpositive(st0_ptr);
32 clear_C1();
33 } else
34 FPU_stack_underflow();
35}
36
37static void ftst_(FPU_REG *st0_ptr, u_char st0tag)
38{
39 switch (st0tag) {
40 case TAG_Zero:
41 setcc(SW_C3);
42 break;
43 case TAG_Valid:
44 if (getsign(st0_ptr) == SIGN_POS)
45 setcc(0);
46 else
47 setcc(SW_C0);
48 break;
49 case TAG_Special:
50 switch (FPU_Special(st0_ptr)) {
51 case TW_Denormal:
52 if (getsign(st0_ptr) == SIGN_POS)
53 setcc(0);
54 else
55 setcc(SW_C0);
56 if (denormal_operand() < 0) {
57#ifdef PECULIAR_486
58 /* This is weird! */
59 if (getsign(st0_ptr) == SIGN_POS)
60 setcc(SW_C3);
61#endif /* PECULIAR_486 */
62 return;
63 }
64 break;
65 case TW_NaN:
66 setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
67 EXCEPTION(EX_Invalid);
68 break;
69 case TW_Infinity:
70 if (getsign(st0_ptr) == SIGN_POS)
71 setcc(0);
72 else
73 setcc(SW_C0);
74 break;
75 default:
76 setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
77 EXCEPTION(EX_INTERNAL | 0x14);
78 break;
79 }
80 break;
81 case TAG_Empty:
82 setcc(SW_C0 | SW_C2 | SW_C3);
83 EXCEPTION(EX_StackUnder);
84 break;
85 }
86}
87
88static void fxam(FPU_REG *st0_ptr, u_char st0tag)
89{
90 int c = 0;
91 switch (st0tag) {
92 case TAG_Empty:
93 c = SW_C3 | SW_C0;
94 break;
95 case TAG_Zero:
96 c = SW_C3;
97 break;
98 case TAG_Valid:
99 c = SW_C2;
100 break;
101 case TAG_Special:
102 switch (FPU_Special(st0_ptr)) {
103 case TW_Denormal:
104 c = SW_C2 | SW_C3; /* Denormal */
105 break;
106 case TW_NaN:
107 /* We also use NaN for unsupported types. */
108 if ((st0_ptr->sigh & 0x80000000)
109 && (exponent(st0_ptr) == EXP_OVER))
110 c = SW_C0;
111 break;
112 case TW_Infinity:
113 c = SW_C2 | SW_C0;
114 break;
115 }
116 }
117 if (getsign(st0_ptr) == SIGN_NEG)
118 c |= SW_C1;
119 setcc(c);
120}
121
122static FUNC_ST0 const fp_etc_table[] = {
123 fchs, fabs, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal,
124 ftst_, fxam, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal
125};
126
127void FPU_etc(void)
128{
129 (fp_etc_table[FPU_rm]) (&st(0), FPU_gettag0());
130}
1// SPDX-License-Identifier: GPL-2.0
2/*---------------------------------------------------------------------------+
3 | fpu_etc.c |
4 | |
5 | Implement a few FPU instructions. |
6 | |
7 | Copyright (C) 1992,1993,1994,1997 |
8 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
9 | Australia. E-mail billm@suburbia.net |
10 | |
11 | |
12 +---------------------------------------------------------------------------*/
13
14#include "fpu_system.h"
15#include "exception.h"
16#include "fpu_emu.h"
17#include "status_w.h"
18#include "reg_constant.h"
19
20static void fchs(FPU_REG *st0_ptr, u_char st0tag)
21{
22 if (st0tag ^ TAG_Empty) {
23 signbyte(st0_ptr) ^= SIGN_NEG;
24 clear_C1();
25 } else
26 FPU_stack_underflow();
27}
28
29static void fabs(FPU_REG *st0_ptr, u_char st0tag)
30{
31 if (st0tag ^ TAG_Empty) {
32 setpositive(st0_ptr);
33 clear_C1();
34 } else
35 FPU_stack_underflow();
36}
37
38static void ftst_(FPU_REG *st0_ptr, u_char st0tag)
39{
40 switch (st0tag) {
41 case TAG_Zero:
42 setcc(SW_C3);
43 break;
44 case TAG_Valid:
45 if (getsign(st0_ptr) == SIGN_POS)
46 setcc(0);
47 else
48 setcc(SW_C0);
49 break;
50 case TAG_Special:
51 switch (FPU_Special(st0_ptr)) {
52 case TW_Denormal:
53 if (getsign(st0_ptr) == SIGN_POS)
54 setcc(0);
55 else
56 setcc(SW_C0);
57 if (denormal_operand() < 0) {
58#ifdef PECULIAR_486
59 /* This is weird! */
60 if (getsign(st0_ptr) == SIGN_POS)
61 setcc(SW_C3);
62#endif /* PECULIAR_486 */
63 return;
64 }
65 break;
66 case TW_NaN:
67 setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
68 EXCEPTION(EX_Invalid);
69 break;
70 case TW_Infinity:
71 if (getsign(st0_ptr) == SIGN_POS)
72 setcc(0);
73 else
74 setcc(SW_C0);
75 break;
76 default:
77 setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
78 EXCEPTION(EX_INTERNAL | 0x14);
79 break;
80 }
81 break;
82 case TAG_Empty:
83 setcc(SW_C0 | SW_C2 | SW_C3);
84 EXCEPTION(EX_StackUnder);
85 break;
86 }
87}
88
89static void fxam(FPU_REG *st0_ptr, u_char st0tag)
90{
91 int c = 0;
92 switch (st0tag) {
93 case TAG_Empty:
94 c = SW_C3 | SW_C0;
95 break;
96 case TAG_Zero:
97 c = SW_C3;
98 break;
99 case TAG_Valid:
100 c = SW_C2;
101 break;
102 case TAG_Special:
103 switch (FPU_Special(st0_ptr)) {
104 case TW_Denormal:
105 c = SW_C2 | SW_C3; /* Denormal */
106 break;
107 case TW_NaN:
108 /* We also use NaN for unsupported types. */
109 if ((st0_ptr->sigh & 0x80000000)
110 && (exponent(st0_ptr) == EXP_OVER))
111 c = SW_C0;
112 break;
113 case TW_Infinity:
114 c = SW_C2 | SW_C0;
115 break;
116 }
117 }
118 if (getsign(st0_ptr) == SIGN_NEG)
119 c |= SW_C1;
120 setcc(c);
121}
122
123static void FPU_ST0_illegal(FPU_REG *st0_ptr, u_char st0_tag)
124{
125 FPU_illegal();
126}
127
128static FUNC_ST0 const fp_etc_table[] = {
129 fchs, fabs, FPU_ST0_illegal, FPU_ST0_illegal,
130 ftst_, fxam, FPU_ST0_illegal, FPU_ST0_illegal,
131};
132
133void FPU_etc(void)
134{
135 (fp_etc_table[FPU_rm]) (&st(0), FPU_gettag0());
136}