1 // SPDX-License-Identifier: GPL-2.0 1
2 /*--------------------------------------------
3 | reg_constant.c
4 |
5 | All of the constant FPU_REGs
6 |
7 | Copyright (C) 1992,1993,1994,1997
8 | W. Metzenthen, 22 Parke
9 | Australia. E-mail bi
10 |
11 |
12 +--------------------------------------------
13
14 #include "fpu_system.h"
15 #include "fpu_emu.h"
16 #include "status_w.h"
17 #include "reg_constant.h"
18 #include "control_w.h"
19
20 #define MAKE_REG(s, e, l, h) { l, h, \
21 (u16)((EXTENDED_Ebias+(e)) | (
22
23 FPU_REG const CONST_1 = MAKE_REG(POS, 0, 0x000
24 #if 0
25 FPU_REG const CONST_2 = MAKE_REG(POS, 1, 0x000
26 FPU_REG const CONST_HALF = MAKE_REG(POS, -1, 0
27 #endif /* 0 */
28 static FPU_REG const CONST_L2T = MAKE_REG(POS,
29 static FPU_REG const CONST_L2E = MAKE_REG(POS,
30 FPU_REG const CONST_PI = MAKE_REG(POS, 1, 0x21
31 FPU_REG const CONST_PI2 = MAKE_REG(POS, 0, 0x2
32 FPU_REG const CONST_PI4 = MAKE_REG(POS, -1, 0x
33 static FPU_REG const CONST_LG2 = MAKE_REG(POS,
34 static FPU_REG const CONST_LN2 = MAKE_REG(POS,
35
36 /* Extra bits to take pi/2 to more than 128 bi
37 FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -
38 0xfc8f
39
40 /* Only the sign (and tag) is used in internal
41 FPU_REG const CONST_Z = MAKE_REG(POS, EXP_UNDE
42
43 /* Only the sign and significand (and tag) are
44 /* The 80486 never generates one of these
45 FPU_REG const CONST_SNAN = MAKE_REG(POS, EXP_O
46 */
47 /* This is the real indefinite QNaN */
48 FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_O
49
50 /* Only the sign (and tag) is used in internal
51 FPU_REG const CONST_INF = MAKE_REG(POS, EXP_OV
52
53 static void fld_const(FPU_REG const * c, int a
54 {
55 FPU_REG *st_new_ptr;
56
57 if (STACK_OVERFLOW) {
58 FPU_stack_overflow();
59 return;
60 }
61 push();
62 reg_copy(c, st_new_ptr);
63 st_new_ptr->sigl += adj; /* For
64 bor
65 FPU_settag0(tag);
66 clear_C1();
67 }
68
69 /* A fast way to find out whether x is one of
70 (and not one of RC_RND or RC_UP).
71 */
72 #define DOWN_OR_CHOP(x) (x & RC_DOWN)
73
74 static void fld1(int rc)
75 {
76 fld_const(&CONST_1, 0, TAG_Valid);
77 }
78
79 static void fldl2t(int rc)
80 {
81 fld_const(&CONST_L2T, (rc == RC_UP) ?
82 }
83
84 static void fldl2e(int rc)
85 {
86 fld_const(&CONST_L2E, DOWN_OR_CHOP(rc)
87 }
88
89 static void fldpi(int rc)
90 {
91 fld_const(&CONST_PI, DOWN_OR_CHOP(rc)
92 }
93
94 static void fldlg2(int rc)
95 {
96 fld_const(&CONST_LG2, DOWN_OR_CHOP(rc)
97 }
98
99 static void fldln2(int rc)
100 {
101 fld_const(&CONST_LN2, DOWN_OR_CHOP(rc)
102 }
103
104 static void fldz(int rc)
105 {
106 fld_const(&CONST_Z, 0, TAG_Zero);
107 }
108
109 typedef void (*FUNC_RC) (int);
110
111 static void FPU_RC_illegal(int unused)
112 {
113 FPU_illegal();
114 }
115
116 static FUNC_RC constants_table[] = {
117 fld1, fldl2t, fldl2e, fldpi, fldlg2, f
118 };
119
120 void fconst(void)
121 {
122 (constants_table[FPU_rm]) (control_wor
123 }
124
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