1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /*---------------------------------------------------------------------------+ |
3 | | fpu_tags.c | |
4 | | | |
5 | | Set FPU register tags. | |
6 | | | |
7 | | Copyright (C) 1997 | |
8 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | |
9 | | E-mail billm@jacobi.maths.monash.edu.au | |
10 | | | |
11 | | | |
12 | +---------------------------------------------------------------------------*/ |
13 | |
14 | #include "fpu_emu.h" |
15 | #include "fpu_system.h" |
16 | #include "exception.h" |
17 | |
18 | void FPU_pop(void) |
19 | { |
20 | fpu_tag_word |= 3 << ((top & 7) * 2); |
21 | top++; |
22 | } |
23 | |
24 | int FPU_gettag0(void) |
25 | { |
26 | return (fpu_tag_word >> ((top & 7) * 2)) & 3; |
27 | } |
28 | |
29 | int FPU_gettagi(int stnr) |
30 | { |
31 | return (fpu_tag_word >> (((top + stnr) & 7) * 2)) & 3; |
32 | } |
33 | |
34 | int FPU_gettag(int regnr) |
35 | { |
36 | return (fpu_tag_word >> ((regnr & 7) * 2)) & 3; |
37 | } |
38 | |
39 | void FPU_settag0(int tag) |
40 | { |
41 | int regnr = top; |
42 | regnr &= 7; |
43 | fpu_tag_word &= ~(3 << (regnr * 2)); |
44 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
45 | } |
46 | |
47 | void FPU_settagi(int stnr, int tag) |
48 | { |
49 | int regnr = stnr + top; |
50 | regnr &= 7; |
51 | fpu_tag_word &= ~(3 << (regnr * 2)); |
52 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
53 | } |
54 | |
55 | void FPU_settag(int regnr, int tag) |
56 | { |
57 | regnr &= 7; |
58 | fpu_tag_word &= ~(3 << (regnr * 2)); |
59 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
60 | } |
61 | |
62 | int FPU_Special(FPU_REG const *ptr) |
63 | { |
64 | int exp = exponent(ptr); |
65 | |
66 | if (exp == EXP_BIAS + EXP_UNDER) |
67 | return TW_Denormal; |
68 | else if (exp != EXP_BIAS + EXP_OVER) |
69 | return TW_NaN; |
70 | else if ((ptr->sigh == 0x80000000) && (ptr->sigl == 0)) |
71 | return TW_Infinity; |
72 | return TW_NaN; |
73 | } |
74 | |
75 | int isNaN(FPU_REG const *ptr) |
76 | { |
77 | return ((exponent(ptr) == EXP_BIAS + EXP_OVER) |
78 | && !((ptr->sigh == 0x80000000) && (ptr->sigl == 0))); |
79 | } |
80 | |
81 | int FPU_empty_i(int stnr) |
82 | { |
83 | int regnr = (top + stnr) & 7; |
84 | |
85 | return ((fpu_tag_word >> (regnr * 2)) & 3) == TAG_Empty; |
86 | } |
87 | |
88 | int FPU_stackoverflow(FPU_REG ** st_new_ptr) |
89 | { |
90 | *st_new_ptr = &st(-1); |
91 | |
92 | return ((fpu_tag_word >> (((top - 1) & 7) * 2)) & 3) != TAG_Empty; |
93 | } |
94 | |
95 | void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr) |
96 | { |
97 | reg_copy(x: r, y: &st(stnr)); |
98 | FPU_settagi(stnr, tag); |
99 | } |
100 | |
101 | void FPU_copy_to_reg1(FPU_REG const *r, u_char tag) |
102 | { |
103 | reg_copy(x: r, y: &st(1)); |
104 | FPU_settagi(stnr: 1, tag); |
105 | } |
106 | |
107 | void FPU_copy_to_reg0(FPU_REG const *r, u_char tag) |
108 | { |
109 | int regnr = top; |
110 | regnr &= 7; |
111 | |
112 | reg_copy(x: r, y: &st(0)); |
113 | |
114 | fpu_tag_word &= ~(3 << (regnr * 2)); |
115 | fpu_tag_word |= (tag & 3) << (regnr * 2); |
116 | } |
117 | |