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cf447356 GL |
1 | #include "wx/setup.h" |
2 | #include <math.h> | |
3 | ||
126eb09b | 4 | #if wxUSE_APPLE_IEEE |
cf447356 GL |
5 | |
6 | /* | |
7 | * C O N V E R T T O I E E E E X T E N D E D | |
8 | */ | |
9 | ||
10 | /* Copyright (C) 1988-1991 Apple Computer, Inc. | |
11 | * All rights reserved. | |
12 | * | |
13 | * Machine-independent I/O routines for IEEE floating-point numbers. | |
14 | * | |
15 | * NaN's and infinities are converted to HUGE_VAL or HUGE, which | |
16 | * happens to be infinity on IEEE machines. Unfortunately, it is | |
17 | * impossible to preserve NaN's in a machine-independent way. | |
18 | * Infinities are, however, preserved on IEEE machines. | |
19 | * | |
20 | * These routines have been tested on the following machines: | |
21 | * Apple Macintosh, MPW 3.1 C compiler | |
22 | * Apple Macintosh, THINK C compiler | |
23 | * Silicon Graphics IRIS, MIPS compiler | |
24 | * Cray X/MP and Y/MP | |
25 | * Digital Equipment VAX | |
26 | * | |
27 | * | |
28 | * Implemented by Malcolm Slaney and Ken Turkowski. | |
29 | * | |
30 | * Malcolm Slaney contributions during 1988-1990 include big- and little- | |
31 | * endian file I/O, conversion to and from Motorola's extended 80-bit | |
32 | * floating-point format, and conversions to and from IEEE single- | |
33 | * precision floating-point format. | |
34 | * | |
35 | * In 1991, Ken Turkowski implemented the conversions to and from | |
36 | * IEEE double-precision format, added more precision to the extended | |
37 | * conversions, and accommodated conversions involving +/- infinity, | |
38 | * NaN's, and denormalized numbers. | |
39 | */ | |
40 | ||
41 | #ifndef HUGE_VAL | |
42 | #define HUGE_VAL HUGE | |
43 | #endif /*HUGE_VAL*/ | |
44 | ||
45 | #define FloatToUnsigned(f) ((unsigned long) (((long) (f - 2147483648.0)) + 2147483647L) + 1) | |
46 | ||
47 | void ConvertToIeeeExtended(double num, unsigned char *bytes) | |
48 | { | |
49 | int sign; | |
50 | int expon; | |
51 | double fMant, fsMant; | |
52 | unsigned long hiMant, loMant; | |
53 | ||
54 | if (num < 0) { | |
55 | sign = 0x8000; | |
56 | num *= -1; | |
57 | } else { | |
58 | sign = 0; | |
59 | } | |
60 | ||
61 | if (num == 0) { | |
62 | expon = 0; hiMant = 0; loMant = 0; | |
63 | } | |
64 | else { | |
65 | fMant = frexp(num, &expon); | |
66 | if ((expon > 16384) || !(fMant < 1)) { /* Infinity or NaN */ | |
67 | expon = sign|0x7FFF; hiMant = 0; loMant = 0; /* infinity */ | |
68 | } | |
69 | else { /* Finite */ | |
70 | expon += 16382; | |
71 | if (expon < 0) { /* denormalized */ | |
72 | fMant = ldexp(fMant, expon); | |
73 | expon = 0; | |
74 | } | |
75 | expon |= sign; | |
76 | fMant = ldexp(fMant, 32); | |
77 | fsMant = floor(fMant); | |
78 | hiMant = FloatToUnsigned(fsMant); | |
79 | fMant = ldexp(fMant - fsMant, 32); | |
80 | fsMant = floor(fMant); | |
81 | loMant = FloatToUnsigned(fsMant); | |
82 | } | |
83 | } | |
84 | ||
777553d2 | 85 | /* disable the warning about 'possible loss of data' */ |
84a19dec VZ |
86 | #ifdef _MSC_VER |
87 | #pragma warning(disable: 4244) | |
777553d2 | 88 | #endif /* Visual C++ */ |
84a19dec | 89 | |
e03bcf0d GL |
90 | bytes[0] = (expon >> 8) & 0xff; |
91 | bytes[1] = expon & 0xff; | |
92 | bytes[2] = (unsigned char) ((hiMant >> 24) & 0xff); | |
93 | bytes[3] = (unsigned char) ((hiMant >> 16) & 0xff); | |
94 | bytes[4] = (unsigned char) ((hiMant >> 8) & 0xff); | |
95 | bytes[5] = (unsigned char) (hiMant & 0xff); | |
96 | bytes[6] = (unsigned char) ((loMant >> 24) & 0xff); | |
97 | bytes[7] = (unsigned char) ((loMant >> 16) & 0xff); | |
98 | bytes[8] = (unsigned char) ((loMant >> 8) & 0xff); | |
44719c47 | 99 | bytes[9] = (unsigned char) (loMant & 0xff); |
84a19dec VZ |
100 | |
101 | #ifdef _MSC_VER | |
102 | #pragma warning(default: 4244) | |
777553d2 | 103 | #endif /* Visual C++ */ |
cf447356 GL |
104 | } |
105 | ||
106 | /* | |
107 | * C O N V E R T F R O M I E E E E X T E N D E D | |
108 | */ | |
109 | ||
110 | /* | |
111 | * Copyright (C) 1988-1991 Apple Computer, Inc. | |
112 | * All rights reserved. | |
113 | * | |
114 | * Machine-independent I/O routines for IEEE floating-point numbers. | |
115 | * | |
116 | * NaN's and infinities are converted to HUGE_VAL or HUGE, which | |
117 | * happens to be infinity on IEEE machines. Unfortunately, it is | |
118 | * impossible to preserve NaN's in a machine-independent way. | |
119 | * Infinities are, however, preserved on IEEE machines. | |
120 | * | |
121 | * These routines have been tested on the following machines: | |
122 | * Apple Macintosh, MPW 3.1 C compiler | |
123 | * Apple Macintosh, THINK C compiler | |
124 | * Silicon Graphics IRIS, MIPS compiler | |
125 | * Cray X/MP and Y/MP | |
126 | * Digital Equipment VAX | |
127 | * | |
128 | * | |
129 | * Implemented by Malcolm Slaney and Ken Turkowski. | |
130 | * | |
131 | * Malcolm Slaney contributions during 1988-1990 include big- and little- | |
132 | * endian file I/O, conversion to and from Motorola's extended 80-bit | |
133 | * floating-point format, and conversions to and from IEEE single- | |
134 | * precision floating-point format. | |
135 | * | |
136 | * In 1991, Ken Turkowski implemented the conversions to and from | |
137 | * IEEE double-precision format, added more precision to the extended | |
138 | * conversions, and accommodated conversions involving +/- infinity, | |
139 | * NaN's, and denormalized numbers. | |
140 | */ | |
141 | ||
142 | #ifndef HUGE_VAL | |
143 | # define HUGE_VAL HUGE | |
144 | #endif /*HUGE_VAL*/ | |
145 | ||
146 | # define UnsignedToFloat(u) (((double) ((long) (u - 2147483647L - 1))) + 2147483648.0) | |
147 | ||
148 | /**************************************************************** | |
149 | * Extended precision IEEE floating-point conversion routine. | |
150 | ****************************************************************/ | |
151 | ||
152 | double ConvertFromIeeeExtended(const unsigned char *bytes) | |
153 | { | |
154 | double f; | |
155 | int expon; | |
156 | unsigned long hiMant, loMant; | |
157 | ||
158 | expon = ((bytes[0] & 0x7F) << 8) | (bytes[1] & 0xFF); | |
159 | hiMant = ((unsigned long)(bytes[2] & 0xFF) << 24) | |
160 | | ((unsigned long) (bytes[3] & 0xFF) << 16) | |
161 | | ((unsigned long) (bytes[4] & 0xFF) << 8) | |
162 | | ((unsigned long) (bytes[5] & 0xFF)); | |
163 | loMant = ((unsigned long) (bytes[6] & 0xFF) << 24) | |
164 | | ((unsigned long) (bytes[7] & 0xFF) << 16) | |
165 | | ((unsigned long) (bytes[8] & 0xFF) << 8) | |
166 | | ((unsigned long) (bytes[9] & 0xFF)); | |
167 | ||
168 | if (expon == 0 && hiMant == 0 && loMant == 0) { | |
169 | f = 0; | |
170 | } | |
171 | else { | |
172 | if (expon == 0x7FFF) { /* Infinity or NaN */ | |
173 | f = HUGE_VAL; | |
174 | } | |
175 | else { | |
176 | expon -= 16383; | |
177 | f = ldexp(UnsignedToFloat(hiMant), expon-=31); | |
178 | f += ldexp(UnsignedToFloat(loMant), expon-=32); | |
179 | } | |
180 | } | |
181 | ||
182 | if (bytes[0] & 0x80) | |
183 | return -f; | |
184 | else | |
185 | return f; | |
186 | } | |
187 | ||
44c4a334 | 188 | #endif /* wxUSE_APPLE_IEEE */ |