1 /*
2 * UAE - The Un*x Amiga Emulator
3 *
4 * MC68881 emulation
5 *
6 * Conversion routines for hosts with unknown floating point format.
7 *
8 * Copyright 1996 Herman ten Brugge
9 */
10
11 #ifndef UAE_FPP_UNKNOWN_H
12 #define UAE_FPP_UNKNOWN_H
13
14 #include "uae/types.h"
15 #ifdef FSUAE
16 #include "uae/inline.h"
17 #include <math.h>
18 #endif
19
20 #ifndef HAVE_to_single
to_single(uae_u32 value)21 STATIC_INLINE double to_single (uae_u32 value)
22 {
23 double frac;
24
25 if ((value & 0x7fffffff) == 0)
26 return (0.0);
27 frac = (double) ((value & 0x7fffff) | 0x800000) / 8388608.0;
28 if (value & 0x80000000)
29 frac = -frac;
30 return (ldexp (frac, ((value >> 23) & 0xff) - 127));
31 }
32 #endif
33
34 #ifndef HAVE_from_single
from_single(double src)35 STATIC_INLINE uae_u32 from_single (double src)
36 {
37 int expon;
38 uae_u32 tmp;
39 double frac;
40
41 if (src == 0.0)
42 return 0;
43 if (src < 0) {
44 tmp = 0x80000000;
45 src = -src;
46 } else {
47 tmp = 0;
48 }
49 frac = frexp (src, &expon);
50 frac += 0.5 / 16777216.0;
51 if (frac >= 1.0) {
52 frac /= 2.0;
53 expon++;
54 }
55 return (tmp | (((expon + 127 - 1) & 0xff) << 23) |
56 (((int) (frac * 16777216.0)) & 0x7fffff));
57 }
58 #endif
59
60 #ifndef HAVE_to_exten
to_exten(uae_u32 wrd1,uae_u32 wrd2,uae_u32 wrd3)61 STATIC_INLINE double to_exten(uae_u32 wrd1, uae_u32 wrd2, uae_u32 wrd3)
62 {
63 double frac;
64
65 if ((wrd1 & 0x7fff0000) == 0 && wrd2 == 0 && wrd3 == 0)
66 return 0.0;
67 frac = (double) wrd2 / 2147483648.0 +
68 (double) wrd3 / 9223372036854775808.0;
69 if (wrd1 & 0x80000000)
70 frac = -frac;
71 return ldexp (frac, ((wrd1 >> 16) & 0x7fff) - 16383);
72 }
73 #endif
74
75 #ifndef HAVE_from_exten
from_exten(double src,uae_u32 * wrd1,uae_u32 * wrd2,uae_u32 * wrd3)76 STATIC_INLINE void from_exten(double src, uae_u32 * wrd1, uae_u32 * wrd2, uae_u32 * wrd3)
77 {
78 int expon;
79 double frac;
80
81 if (src == 0.0) {
82 *wrd1 = 0;
83 *wrd2 = 0;
84 *wrd3 = 0;
85 return;
86 }
87 if (src < 0) {
88 *wrd1 = 0x80000000;
89 src = -src;
90 } else {
91 *wrd1 = 0;
92 }
93 frac = frexp (src, &expon);
94 frac += 0.5 / 18446744073709551616.0;
95 if (frac >= 1.0) {
96 frac /= 2.0;
97 expon++;
98 }
99 *wrd1 |= (((expon + 16383 - 1) & 0x7fff) << 16);
100 *wrd2 = (uae_u32) (frac * 4294967296.0);
101 *wrd3 = (uae_u32) (frac * 18446744073709551616.0 - *wrd2 * 4294967296.0);
102 }
103 #endif
104
105 #ifndef HAVE_to_double
to_double(uae_u32 wrd1,uae_u32 wrd2)106 STATIC_INLINE double to_double(uae_u32 wrd1, uae_u32 wrd2)
107 {
108 double frac;
109
110 if ((wrd1 & 0x7fffffff) == 0 && wrd2 == 0)
111 return 0.0;
112 frac = (double) ((wrd1 & 0xfffff) | 0x100000) / 1048576.0 +
113 (double) wrd2 / 4503599627370496.0;
114 if (wrd1 & 0x80000000)
115 frac = -frac;
116 return ldexp (frac, ((wrd1 >> 20) & 0x7ff) - 1023);
117 }
118 #endif
119
120 #ifndef HAVE_from_double
from_double(double src,uae_u32 * wrd1,uae_u32 * wrd2)121 STATIC_INLINE void from_double(double src, uae_u32 * wrd1, uae_u32 * wrd2)
122 {
123 int expon;
124 int tmp;
125 double frac;
126
127 if (src == 0.0) {
128 *wrd1 = 0;
129 *wrd2 = 0;
130 return;
131 }
132 if (src < 0) {
133 *wrd1 = 0x80000000;
134 src = -src;
135 } else {
136 *wrd1 = 0;
137 }
138 frac = frexp (src, &expon);
139 frac += 0.5 / 9007199254740992.0;
140 if (frac >= 1.0) {
141 frac /= 2.0;
142 expon++;
143 }
144 tmp = (uae_u32) (frac * 2097152.0);
145 *wrd1 |= (((expon + 1023 - 1) & 0x7ff) << 20) | (tmp & 0xfffff);
146 *wrd2 = (uae_u32) (frac * 9007199254740992.0 - tmp * 4294967296.0);
147 }
148 #endif
149
150 #endif /* UAE_FPP_UNKNOWN_H */
151