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d4052bcb RN |
1 | /***************************************************************************** |
2 | ** Name: extended.c | |
3 | ** Purpose: IEEE Extended<->Double routines to save floats to file | |
4 | ** Maintainer: Ryan Norton | |
5 | ** Modified by: | |
6 | ** Created: 11/24/04 | |
7 | ** RCS-ID: $Id$ | |
8 | *****************************************************************************/ | |
5b7f1aab | 9 | |
d4052bcb | 10 | |
040e5f77 | 11 | #if defined(_WIN32_WCE) |
3b2b40b4 | 12 | /* eVC cause warnings in its own headers: stdlib.h and winnt.h */ |
61f824b8 WS |
13 | #pragma warning (disable:4115) |
14 | #pragma warning (disable:4214) | |
15 | #endif | |
16 | ||
6e848e93 WS |
17 | #include <stdio.h> |
18 | #include <stdlib.h> | |
19 | #include <ctype.h> | |
20 | #include <limits.h> | |
21 | #include <string.h> | |
d4052bcb | 22 | #include "wx/defs.h" |
cf447356 | 23 | |
040e5f77 | 24 | #if defined(_WIN32_WCE) |
61f824b8 WS |
25 | #pragma warning (default:4115) |
26 | #pragma warning (default:4214) | |
27 | #endif | |
28 | ||
126eb09b | 29 | #if wxUSE_APPLE_IEEE |
cf447356 | 30 | |
b713f891 | 31 | #include "wx/math.h" |
cf447356 | 32 | |
d4052bcb RN |
33 | /* Copyright (C) 1989-1991 Ken Turkowski. <turk@computer.org> |
34 | * | |
cf447356 GL |
35 | * All rights reserved. |
36 | * | |
d4052bcb RN |
37 | * Warranty Information |
38 | * Even though I have reviewed this software, I make no warranty | |
39 | * or representation, either express or implied, with respect to this | |
40 | * software, its quality, accuracy, merchantability, or fitness for a | |
41 | * particular purpose. As a result, this software is provided "as is," | |
42 | * and you, its user, are assuming the entire risk as to its quality | |
43 | * and accuracy. | |
44 | * | |
45 | * This code may be used and freely distributed as long as it includes | |
46 | * this copyright notice and the above warranty information. | |
47 | * | |
cf447356 GL |
48 | * Machine-independent I/O routines for IEEE floating-point numbers. |
49 | * | |
50 | * NaN's and infinities are converted to HUGE_VAL or HUGE, which | |
d4052bcb | 51 | * happens to be infinity on IEEE machines. Unfortunately, it is |
cf447356 GL |
52 | * impossible to preserve NaN's in a machine-independent way. |
53 | * Infinities are, however, preserved on IEEE machines. | |
54 | * | |
55 | * These routines have been tested on the following machines: | |
b713f891 WS |
56 | * Apple Macintosh, MPW 3.1 C compiler |
57 | * Apple Macintosh, THINK C compiler | |
58 | * Silicon Graphics IRIS, MIPS compiler | |
59 | * Cray X/MP and Y/MP | |
60 | * Digital Equipment VAX | |
61 | * Sequent Balance (Multiprocesor 386) | |
62 | * NeXT | |
cf447356 GL |
63 | * |
64 | * | |
65 | * Implemented by Malcolm Slaney and Ken Turkowski. | |
66 | * | |
67 | * Malcolm Slaney contributions during 1988-1990 include big- and little- | |
68 | * endian file I/O, conversion to and from Motorola's extended 80-bit | |
69 | * floating-point format, and conversions to and from IEEE single- | |
70 | * precision floating-point format. | |
71 | * | |
72 | * In 1991, Ken Turkowski implemented the conversions to and from | |
73 | * IEEE double-precision format, added more precision to the extended | |
74 | * conversions, and accommodated conversions involving +/- infinity, | |
75 | * NaN's, and denormalized numbers. | |
76 | */ | |
77 | ||
78 | #ifndef HUGE_VAL | |
d4052bcb | 79 | # define HUGE_VAL HUGE |
47b3cc5c | 80 | #endif /*HUGE_VAL*/ |
cf447356 | 81 | |
cf447356 | 82 | |
d4052bcb RN |
83 | /**************************************************************** |
84 | * The following two routines make up for deficiencies in many | |
85 | * compilers to convert properly between unsigned integers and | |
86 | * floating-point. Some compilers which have this bug are the | |
87 | * THINK_C compiler for the Macintosh and the C compiler for the | |
88 | * Silicon Graphics MIPS-based Iris. | |
89 | ****************************************************************/ | |
cf447356 | 90 | |
b713f891 WS |
91 | #ifdef applec /* The Apple C compiler works */ |
92 | # define FloatToUnsigned(f) ((wxUint32)(f)) | |
93 | # define UnsignedToFloat(u) ((wxFloat64)(u)) | |
47b3cc5c | 94 | #else /*applec*/ |
b713f891 WS |
95 | # define FloatToUnsigned(f) ((wxUint32)(((wxInt32)((f) - 2147483648.0)) + 2147483647L) + 1) |
96 | # define UnsignedToFloat(u) (((wxFloat64)((wxInt32)((u) - 2147483647L - 1))) + 2147483648.0) | |
47b3cc5c | 97 | #endif /*applec*/ |
cf447356 | 98 | |
cf447356 | 99 | |
b713f891 | 100 | |
cf447356 | 101 | /**************************************************************** |
d4052bcb RN |
102 | * Extended precision IEEE floating-point conversion routines. |
103 | * Extended is an 80-bit number as defined by Motorola, | |
104 | * with a sign bit, 15 bits of exponent (offset 16383?), | |
105 | * and a 64-bit mantissa, with no hidden bit. | |
cf447356 GL |
106 | ****************************************************************/ |
107 | ||
163b3ad7 | 108 | WXDLLIMPEXP_BASE wxFloat64 wxConvertFromIeeeExtended(const wxInt8 *bytes) |
cf447356 | 109 | { |
b713f891 WS |
110 | wxFloat64 f; |
111 | wxInt32 expon; | |
112 | wxUint32 hiMant, loMant; | |
113 | ||
114 | expon = ((bytes[0] & 0x7F) << 8) | (bytes[1] & 0xFF); | |
115 | hiMant = ((wxUint32)(bytes[2] & 0xFF) << 24) | |
116 | | ((wxUint32)(bytes[3] & 0xFF) << 16) | |
117 | | ((wxUint32)(bytes[4] & 0xFF) << 8) | |
118 | | ((wxUint32)(bytes[5] & 0xFF)); | |
119 | loMant = ((wxUint32)(bytes[6] & 0xFF) << 24) | |
120 | | ((wxUint32)(bytes[7] & 0xFF) << 16) | |
121 | | ((wxUint32)(bytes[8] & 0xFF) << 8) | |
122 | | ((wxUint32)(bytes[9] & 0xFF)); | |
123 | ||
124 | if (expon == 0 && hiMant == 0 && loMant == 0) { | |
125 | f = 0; | |
126 | } | |
127 | else { | |
128 | if (expon == 0x7FFF) { /* Infinity or NaN */ | |
129 | f = HUGE_VAL; | |
130 | } | |
131 | else { | |
132 | expon -= 16383; | |
133 | f = ldexp(UnsignedToFloat(hiMant), expon-=31); | |
134 | f += ldexp(UnsignedToFloat(loMant), expon-=32); | |
135 | } | |
136 | } | |
137 | ||
138 | if (bytes[0] & 0x80) | |
139 | return -f; | |
140 | else | |
141 | return f; | |
cf447356 GL |
142 | } |
143 | ||
d4052bcb RN |
144 | |
145 | /****************************************************************/ | |
146 | ||
147 | ||
163b3ad7 | 148 | WXDLLIMPEXP_BASE void wxConvertToIeeeExtended(wxFloat64 num, wxInt8 *bytes) |
d4052bcb | 149 | { |
b713f891 WS |
150 | wxInt32 sign; |
151 | wxInt32 expon; | |
152 | wxFloat64 fMant, fsMant; | |
153 | wxUint32 hiMant, loMant; | |
154 | ||
155 | if (num < 0) { | |
156 | sign = 0x8000; | |
157 | num *= -1; | |
158 | } else { | |
159 | sign = 0; | |
160 | } | |
161 | ||
162 | if (num == 0) { | |
163 | expon = 0; hiMant = 0; loMant = 0; | |
164 | } | |
165 | else { | |
166 | fMant = frexp(num, &expon); | |
167 | if ((expon > 16384) || !(fMant < 1)) { /* Infinity or NaN */ | |
168 | expon = sign|0x7FFF; hiMant = 0; loMant = 0; /* infinity */ | |
169 | } | |
170 | else { /* Finite */ | |
171 | expon += 16382; | |
172 | if (expon < 0) { /* denormalized */ | |
173 | fMant = ldexp(fMant, expon); | |
174 | expon = 0; | |
175 | } | |
176 | expon |= sign; | |
177 | fMant = ldexp(fMant, 32); fsMant = floor(fMant); hiMant = FloatToUnsigned(fsMant); | |
178 | fMant = ldexp(fMant - fsMant, 32); fsMant = floor(fMant); loMant = FloatToUnsigned(fsMant); | |
179 | } | |
180 | } | |
181 | ||
182 | bytes[0] = expon >> 8; | |
183 | bytes[1] = expon; | |
184 | bytes[2] = hiMant >> 24; | |
185 | bytes[3] = hiMant >> 16; | |
186 | bytes[4] = hiMant >> 8; | |
187 | bytes[5] = hiMant; | |
188 | bytes[6] = loMant >> 24; | |
189 | bytes[7] = loMant >> 16; | |
190 | bytes[8] = loMant >> 8; | |
191 | bytes[9] = loMant; | |
d4052bcb RN |
192 | } |
193 | ||
225dfbc5 | 194 | #if WXWIN_COMPATIBILITY_2_8 |
163b3ad7 | 195 | WXDLLIMPEXP_BASE wxFloat64 ConvertFromIeeeExtended(const wxInt8 *bytes) |
225dfbc5 VZ |
196 | { |
197 | return wxConvertFromIeeeExtended(bytes); | |
198 | } | |
d4052bcb | 199 | |
163b3ad7 | 200 | WXDLLIMPEXP_BASE void ConvertToIeeeExtended(wxFloat64 num, wxInt8 *bytes) |
225dfbc5 VZ |
201 | { |
202 | wxConvertToIeeeExtended(num, bytes); | |
203 | } | |
204 | #endif // WXWIN_COMPATIBILITY_2_8 | |
d4052bcb | 205 | |
44c4a334 | 206 | #endif /* wxUSE_APPLE_IEEE */ |