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1// SPDX-License-Identifier: GPL-2.0
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 Parker St, Ormond, Vic 3163, |
9 | Australia. E-mail billm@suburbia.net |
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)) | ((SIGN_##s != 0)*0x8000)) }
22
23FPU_REG const CONST_1 = MAKE_REG(POS, 0, 0x00000000, 0x80000000);
24#if 0
25FPU_REG const CONST_2 = MAKE_REG(POS, 1, 0x00000000, 0x80000000);
26FPU_REG const CONST_HALF = MAKE_REG(POS, -1, 0x00000000, 0x80000000);
27#endif /* 0 */
28static FPU_REG const CONST_L2T = MAKE_REG(POS, 1, 0xcd1b8afe, 0xd49a784b);
29static FPU_REG const CONST_L2E = MAKE_REG(POS, 0, 0x5c17f0bc, 0xb8aa3b29);
30FPU_REG const CONST_PI = MAKE_REG(POS, 1, 0x2168c235, 0xc90fdaa2);
31FPU_REG const CONST_PI2 = MAKE_REG(POS, 0, 0x2168c235, 0xc90fdaa2);
32FPU_REG const CONST_PI4 = MAKE_REG(POS, -1, 0x2168c235, 0xc90fdaa2);
33static FPU_REG const CONST_LG2 = MAKE_REG(POS, -2, 0xfbcff799, 0x9a209a84);
34static FPU_REG const CONST_LN2 = MAKE_REG(POS, -1, 0xd1cf79ac, 0xb17217f7);
35
36/* Extra bits to take pi/2 to more than 128 bits precision. */
37FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -66,
38 0xfc8f8cbb, 0xece675d1);
39
40/* Only the sign (and tag) is used in internal zeroes */
41FPU_REG const CONST_Z = MAKE_REG(POS, EXP_UNDER, 0x0, 0x0);
42
43/* Only the sign and significand (and tag) are used in internal NaNs */
44/* The 80486 never generates one of these
45FPU_REG const CONST_SNAN = MAKE_REG(POS, EXP_OVER, 0x00000001, 0x80000000);
46 */
47/* This is the real indefinite QNaN */
48FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_OVER, 0x00000000, 0xC0000000);
49
50/* Only the sign (and tag) is used in internal infinities */
51FPU_REG const CONST_INF = MAKE_REG(POS, EXP_OVER, 0x00000000, 0x80000000);
52
53static void fld_const(FPU_REG const * c, int adj, u_char tag)
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 all our fldxxx constants, we don't need to
64 borrow or carry. */
65 FPU_settag0(tag);
66 clear_C1();
67}
68
69/* A fast way to find out whether x is one of RC_DOWN or RC_CHOP
70 (and not one of RC_RND or RC_UP).
71 */
72#define DOWN_OR_CHOP(x) (x & RC_DOWN)
73
74static void fld1(int rc)
75{
76 fld_const(&CONST_1, 0, TAG_Valid);
77}
78
79static void fldl2t(int rc)
80{
81 fld_const(&CONST_L2T, (rc == RC_UP) ? 1 : 0, TAG_Valid);
82}
83
84static void fldl2e(int rc)
85{
86 fld_const(&CONST_L2E, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
87}
88
89static void fldpi(int rc)
90{
91 fld_const(&CONST_PI, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
92}
93
94static void fldlg2(int rc)
95{
96 fld_const(&CONST_LG2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
97}
98
99static void fldln2(int rc)
100{
101 fld_const(&CONST_LN2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
102}
103
104static void fldz(int rc)
105{
106 fld_const(&CONST_Z, 0, TAG_Zero);
107}
108
109typedef void (*FUNC_RC) (int);
110
111static FUNC_RC constants_table[] = {
112 fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC) FPU_illegal
113};
114
115void fconst(void)
116{
117 (constants_table[FPU_rm]) (control_word & CW_RC);
118}
1// SPDX-License-Identifier: GPL-2.0
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 Parker St, Ormond, Vic 3163, |
9 | Australia. E-mail billm@suburbia.net |
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)) | ((SIGN_##s != 0)*0x8000)) }
22
23FPU_REG const CONST_1 = MAKE_REG(POS, 0, 0x00000000, 0x80000000);
24#if 0
25FPU_REG const CONST_2 = MAKE_REG(POS, 1, 0x00000000, 0x80000000);
26FPU_REG const CONST_HALF = MAKE_REG(POS, -1, 0x00000000, 0x80000000);
27#endif /* 0 */
28static FPU_REG const CONST_L2T = MAKE_REG(POS, 1, 0xcd1b8afe, 0xd49a784b);
29static FPU_REG const CONST_L2E = MAKE_REG(POS, 0, 0x5c17f0bc, 0xb8aa3b29);
30FPU_REG const CONST_PI = MAKE_REG(POS, 1, 0x2168c235, 0xc90fdaa2);
31FPU_REG const CONST_PI2 = MAKE_REG(POS, 0, 0x2168c235, 0xc90fdaa2);
32FPU_REG const CONST_PI4 = MAKE_REG(POS, -1, 0x2168c235, 0xc90fdaa2);
33static FPU_REG const CONST_LG2 = MAKE_REG(POS, -2, 0xfbcff799, 0x9a209a84);
34static FPU_REG const CONST_LN2 = MAKE_REG(POS, -1, 0xd1cf79ac, 0xb17217f7);
35
36/* Extra bits to take pi/2 to more than 128 bits precision. */
37FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -66,
38 0xfc8f8cbb, 0xece675d1);
39
40/* Only the sign (and tag) is used in internal zeroes */
41FPU_REG const CONST_Z = MAKE_REG(POS, EXP_UNDER, 0x0, 0x0);
42
43/* Only the sign and significand (and tag) are used in internal NaNs */
44/* The 80486 never generates one of these
45FPU_REG const CONST_SNAN = MAKE_REG(POS, EXP_OVER, 0x00000001, 0x80000000);
46 */
47/* This is the real indefinite QNaN */
48FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_OVER, 0x00000000, 0xC0000000);
49
50/* Only the sign (and tag) is used in internal infinities */
51FPU_REG const CONST_INF = MAKE_REG(POS, EXP_OVER, 0x00000000, 0x80000000);
52
53static void fld_const(FPU_REG const * c, int adj, u_char tag)
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 all our fldxxx constants, we don't need to
64 borrow or carry. */
65 FPU_settag0(tag);
66 clear_C1();
67}
68
69/* A fast way to find out whether x is one of RC_DOWN or RC_CHOP
70 (and not one of RC_RND or RC_UP).
71 */
72#define DOWN_OR_CHOP(x) (x & RC_DOWN)
73
74static void fld1(int rc)
75{
76 fld_const(&CONST_1, 0, TAG_Valid);
77}
78
79static void fldl2t(int rc)
80{
81 fld_const(&CONST_L2T, (rc == RC_UP) ? 1 : 0, TAG_Valid);
82}
83
84static void fldl2e(int rc)
85{
86 fld_const(&CONST_L2E, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
87}
88
89static void fldpi(int rc)
90{
91 fld_const(&CONST_PI, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
92}
93
94static void fldlg2(int rc)
95{
96 fld_const(&CONST_LG2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
97}
98
99static void fldln2(int rc)
100{
101 fld_const(&CONST_LN2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
102}
103
104static void fldz(int rc)
105{
106 fld_const(&CONST_Z, 0, TAG_Zero);
107}
108
109typedef void (*FUNC_RC) (int);
110
111static FUNC_RC constants_table[] = {
112 fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC) FPU_illegal
113};
114
115void fconst(void)
116{
117 (constants_table[FPU_rm]) (control_word & CW_RC);
118}