Commit | Line | Data |
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252b5132 | 1 | /* IEEE floating point support routines, for GDB, the GNU Debugger. |
3b6940c0 DD |
2 | Copyright 1991, 1994, 1999, 2000, 2003, 2005 |
3 | Free Software Foundation, Inc. | |
252b5132 RH |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
979c05d3 | 19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
252b5132 | 20 | |
b52927b7 DD |
21 | /* This is needed to pick up the NAN macro on some systems. */ |
22 | #define _GNU_SOURCE | |
23 | ||
24 | #ifdef HAVE_CONFIG_H | |
25 | #include "config.h" | |
26 | #endif | |
27 | ||
28 | #include <math.h> | |
29 | ||
30 | #ifdef HAVE_STRING_H | |
31 | #include <string.h> | |
32 | #endif | |
33 | ||
1ea16ec5 | 34 | #include "ansidecl.h" |
b52927b7 | 35 | #include "libiberty.h" |
252b5132 | 36 | #include "floatformat.h" |
b52927b7 DD |
37 | |
38 | #ifndef INFINITY | |
39 | #ifdef HUGE_VAL | |
40 | #define INFINITY HUGE_VAL | |
252b5132 | 41 | #else |
b52927b7 DD |
42 | #define INFINITY (1.0 / 0.0) |
43 | #endif | |
44 | #endif | |
45 | ||
46 | #ifndef NAN | |
47 | #define NAN (0.0 / 0.0) | |
252b5132 RH |
48 | #endif |
49 | ||
49b1fae4 DD |
50 | static unsigned long get_field (const unsigned char *, |
51 | enum floatformat_byteorders, | |
52 | unsigned int, | |
53 | unsigned int, | |
54 | unsigned int); | |
55 | static int floatformat_always_valid (const struct floatformat *fmt, | |
3b6940c0 | 56 | const void *from); |
5324d185 AC |
57 | |
58 | static int | |
49b1fae4 | 59 | floatformat_always_valid (const struct floatformat *fmt ATTRIBUTE_UNUSED, |
3b6940c0 | 60 | const void *from ATTRIBUTE_UNUSED) |
5324d185 AC |
61 | { |
62 | return 1; | |
63 | } | |
64 | ||
252b5132 RH |
65 | /* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not |
66 | going to bother with trying to muck around with whether it is defined in | |
67 | a system header, what we do if not, etc. */ | |
68 | #define FLOATFORMAT_CHAR_BIT 8 | |
69 | ||
70 | /* floatformats for IEEE single and double, big and little endian. */ | |
71 | const struct floatformat floatformat_ieee_single_big = | |
72 | { | |
f03aa80d AC |
73 | floatformat_big, 32, 0, 1, 8, 127, 255, 9, 23, |
74 | floatformat_intbit_no, | |
5324d185 AC |
75 | "floatformat_ieee_single_big", |
76 | floatformat_always_valid | |
252b5132 RH |
77 | }; |
78 | const struct floatformat floatformat_ieee_single_little = | |
79 | { | |
f03aa80d AC |
80 | floatformat_little, 32, 0, 1, 8, 127, 255, 9, 23, |
81 | floatformat_intbit_no, | |
5324d185 AC |
82 | "floatformat_ieee_single_little", |
83 | floatformat_always_valid | |
252b5132 RH |
84 | }; |
85 | const struct floatformat floatformat_ieee_double_big = | |
86 | { | |
f03aa80d AC |
87 | floatformat_big, 64, 0, 1, 11, 1023, 2047, 12, 52, |
88 | floatformat_intbit_no, | |
5324d185 AC |
89 | "floatformat_ieee_double_big", |
90 | floatformat_always_valid | |
252b5132 RH |
91 | }; |
92 | const struct floatformat floatformat_ieee_double_little = | |
93 | { | |
f03aa80d AC |
94 | floatformat_little, 64, 0, 1, 11, 1023, 2047, 12, 52, |
95 | floatformat_intbit_no, | |
5324d185 AC |
96 | "floatformat_ieee_double_little", |
97 | floatformat_always_valid | |
252b5132 RH |
98 | }; |
99 | ||
100 | /* floatformat for IEEE double, little endian byte order, with big endian word | |
101 | ordering, as on the ARM. */ | |
102 | ||
103 | const struct floatformat floatformat_ieee_double_littlebyte_bigword = | |
104 | { | |
f03aa80d AC |
105 | floatformat_littlebyte_bigword, 64, 0, 1, 11, 1023, 2047, 12, 52, |
106 | floatformat_intbit_no, | |
5324d185 AC |
107 | "floatformat_ieee_double_littlebyte_bigword", |
108 | floatformat_always_valid | |
252b5132 RH |
109 | }; |
110 | ||
fb10537e DD |
111 | /* floatformat for VAX. Not quite IEEE, but close enough. */ |
112 | ||
113 | const struct floatformat floatformat_vax_f = | |
114 | { | |
115 | floatformat_vax, 32, 0, 1, 8, 129, 0, 9, 23, | |
116 | floatformat_intbit_no, | |
117 | "floatformat_vax_f", | |
118 | floatformat_always_valid | |
119 | }; | |
120 | const struct floatformat floatformat_vax_d = | |
121 | { | |
122 | floatformat_vax, 64, 0, 1, 8, 129, 0, 9, 55, | |
123 | floatformat_intbit_no, | |
124 | "floatformat_vax_d", | |
125 | floatformat_always_valid | |
126 | }; | |
127 | const struct floatformat floatformat_vax_g = | |
128 | { | |
129 | floatformat_vax, 64, 0, 1, 11, 1025, 0, 12, 52, | |
130 | floatformat_intbit_no, | |
131 | "floatformat_vax_g", | |
132 | floatformat_always_valid | |
133 | }; | |
134 | ||
3b6940c0 DD |
135 | static int floatformat_i387_ext_is_valid (const struct floatformat *fmt, |
136 | const void *from); | |
5324d185 AC |
137 | |
138 | static int | |
3b6940c0 | 139 | floatformat_i387_ext_is_valid (const struct floatformat *fmt, const void *from) |
5324d185 AC |
140 | { |
141 | /* In the i387 double-extended format, if the exponent is all ones, | |
142 | then the integer bit must be set. If the exponent is neither 0 | |
143 | nor ~0, the intbit must also be set. Only if the exponent is | |
144 | zero can it be zero, and then it must be zero. */ | |
145 | unsigned long exponent, int_bit; | |
3b6940c0 DD |
146 | const unsigned char *ufrom = from; |
147 | ||
5324d185 AC |
148 | exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize, |
149 | fmt->exp_start, fmt->exp_len); | |
150 | int_bit = get_field (ufrom, fmt->byteorder, fmt->totalsize, | |
151 | fmt->man_start, 1); | |
3b6940c0 | 152 | |
5324d185 AC |
153 | if ((exponent == 0) != (int_bit == 0)) |
154 | return 0; | |
155 | else | |
156 | return 1; | |
157 | } | |
158 | ||
252b5132 RH |
159 | const struct floatformat floatformat_i387_ext = |
160 | { | |
161 | floatformat_little, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64, | |
f03aa80d | 162 | floatformat_intbit_yes, |
5324d185 AC |
163 | "floatformat_i387_ext", |
164 | floatformat_i387_ext_is_valid | |
252b5132 RH |
165 | }; |
166 | const struct floatformat floatformat_m68881_ext = | |
167 | { | |
168 | /* Note that the bits from 16 to 31 are unused. */ | |
f03aa80d AC |
169 | floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64, |
170 | floatformat_intbit_yes, | |
5324d185 AC |
171 | "floatformat_m68881_ext", |
172 | floatformat_always_valid | |
252b5132 RH |
173 | }; |
174 | const struct floatformat floatformat_i960_ext = | |
175 | { | |
176 | /* Note that the bits from 0 to 15 are unused. */ | |
177 | floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64, | |
f03aa80d | 178 | floatformat_intbit_yes, |
5324d185 AC |
179 | "floatformat_i960_ext", |
180 | floatformat_always_valid | |
252b5132 RH |
181 | }; |
182 | const struct floatformat floatformat_m88110_ext = | |
183 | { | |
eb828599 AC |
184 | floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64, |
185 | floatformat_intbit_yes, | |
5324d185 AC |
186 | "floatformat_m88110_ext", |
187 | floatformat_always_valid | |
eb828599 AC |
188 | }; |
189 | const struct floatformat floatformat_m88110_harris_ext = | |
190 | { | |
252b5132 RH |
191 | /* Harris uses raw format 128 bytes long, but the number is just an ieee |
192 | double, and the last 64 bits are wasted. */ | |
193 | floatformat_big,128, 0, 1, 11, 0x3ff, 0x7ff, 12, 52, | |
f03aa80d | 194 | floatformat_intbit_no, |
5324d185 AC |
195 | "floatformat_m88110_ext_harris", |
196 | floatformat_always_valid | |
252b5132 | 197 | }; |
eb828599 AC |
198 | const struct floatformat floatformat_arm_ext_big = |
199 | { | |
200 | /* Bits 1 to 16 are unused. */ | |
201 | floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64, | |
202 | floatformat_intbit_yes, | |
5324d185 AC |
203 | "floatformat_arm_ext_big", |
204 | floatformat_always_valid | |
eb828599 AC |
205 | }; |
206 | const struct floatformat floatformat_arm_ext_littlebyte_bigword = | |
207 | { | |
208 | /* Bits 1 to 16 are unused. */ | |
209 | floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64, | |
210 | floatformat_intbit_yes, | |
5324d185 AC |
211 | "floatformat_arm_ext_littlebyte_bigword", |
212 | floatformat_always_valid | |
eb828599 AC |
213 | }; |
214 | const struct floatformat floatformat_ia64_spill_big = | |
215 | { | |
216 | floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64, | |
217 | floatformat_intbit_yes, | |
5324d185 AC |
218 | "floatformat_ia64_spill_big", |
219 | floatformat_always_valid | |
eb828599 AC |
220 | }; |
221 | const struct floatformat floatformat_ia64_spill_little = | |
222 | { | |
223 | floatformat_little, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64, | |
224 | floatformat_intbit_yes, | |
5324d185 AC |
225 | "floatformat_ia64_spill_little", |
226 | floatformat_always_valid | |
eb828599 AC |
227 | }; |
228 | const struct floatformat floatformat_ia64_quad_big = | |
229 | { | |
230 | floatformat_big, 128, 0, 1, 15, 16383, 0x7fff, 16, 112, | |
231 | floatformat_intbit_no, | |
5324d185 AC |
232 | "floatformat_ia64_quad_big", |
233 | floatformat_always_valid | |
eb828599 AC |
234 | }; |
235 | const struct floatformat floatformat_ia64_quad_little = | |
236 | { | |
237 | floatformat_little, 128, 0, 1, 15, 16383, 0x7fff, 16, 112, | |
238 | floatformat_intbit_no, | |
5324d185 AC |
239 | "floatformat_ia64_quad_little", |
240 | floatformat_always_valid | |
eb828599 | 241 | }; |
252b5132 | 242 | \f |
3f2aacaf | 243 | /* Extract a field which starts at START and is LEN bits long. DATA and |
252b5132 RH |
244 | TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ |
245 | static unsigned long | |
49b1fae4 DD |
246 | get_field (const unsigned char *data, enum floatformat_byteorders order, |
247 | unsigned int total_len, unsigned int start, unsigned int len) | |
252b5132 RH |
248 | { |
249 | unsigned long result; | |
250 | unsigned int cur_byte; | |
251 | int cur_bitshift; | |
252 | ||
253 | /* Start at the least significant part of the field. */ | |
254 | cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT; | |
255 | if (order == floatformat_little) | |
256 | cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1; | |
257 | cur_bitshift = | |
258 | ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT; | |
259 | result = *(data + cur_byte) >> (-cur_bitshift); | |
260 | cur_bitshift += FLOATFORMAT_CHAR_BIT; | |
261 | if (order == floatformat_little) | |
262 | ++cur_byte; | |
263 | else | |
264 | --cur_byte; | |
265 | ||
266 | /* Move towards the most significant part of the field. */ | |
08372f14 | 267 | while ((unsigned int) cur_bitshift < len) |
252b5132 RH |
268 | { |
269 | if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT) | |
270 | /* This is the last byte; zero out the bits which are not part of | |
271 | this field. */ | |
272 | result |= | |
273 | (*(data + cur_byte) & ((1 << (len - cur_bitshift)) - 1)) | |
274 | << cur_bitshift; | |
275 | else | |
276 | result |= *(data + cur_byte) << cur_bitshift; | |
277 | cur_bitshift += FLOATFORMAT_CHAR_BIT; | |
278 | if (order == floatformat_little) | |
279 | ++cur_byte; | |
280 | else | |
281 | --cur_byte; | |
282 | } | |
283 | return result; | |
284 | } | |
285 | ||
286 | #ifndef min | |
287 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
288 | #endif | |
289 | ||
290 | /* Convert from FMT to a double. | |
291 | FROM is the address of the extended float. | |
292 | Store the double in *TO. */ | |
293 | ||
294 | void | |
49b1fae4 | 295 | floatformat_to_double (const struct floatformat *fmt, |
3b6940c0 | 296 | const void *from, double *to) |
252b5132 | 297 | { |
3b6940c0 | 298 | const unsigned char *ufrom = from; |
252b5132 RH |
299 | double dto; |
300 | long exponent; | |
301 | unsigned long mant; | |
302 | unsigned int mant_bits, mant_off; | |
303 | int mant_bits_left; | |
304 | int special_exponent; /* It's a NaN, denorm or zero */ | |
305 | ||
306 | exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize, | |
307 | fmt->exp_start, fmt->exp_len); | |
b52927b7 DD |
308 | |
309 | /* If the exponent indicates a NaN, we don't have information to | |
310 | decide what to do. So we handle it like IEEE, except that we | |
311 | don't try to preserve the type of NaN. FIXME. */ | |
312 | if ((unsigned long) exponent == fmt->exp_nan) | |
313 | { | |
314 | int nan; | |
315 | ||
316 | mant_off = fmt->man_start; | |
317 | mant_bits_left = fmt->man_len; | |
318 | nan = 0; | |
319 | while (mant_bits_left > 0) | |
320 | { | |
321 | mant_bits = min (mant_bits_left, 32); | |
322 | ||
323 | if (get_field (ufrom, fmt->byteorder, fmt->totalsize, | |
324 | mant_off, mant_bits) != 0) | |
325 | { | |
326 | /* This is a NaN. */ | |
327 | nan = 1; | |
328 | break; | |
329 | } | |
330 | ||
331 | mant_off += mant_bits; | |
332 | mant_bits_left -= mant_bits; | |
333 | } | |
334 | ||
f2942ea4 DD |
335 | /* On certain systems (such as GNU/Linux), the use of the |
336 | INFINITY macro below may generate a warning that can not be | |
337 | silenced due to a bug in GCC (PR preprocessor/11931). The | |
338 | preprocessor fails to recognise the __extension__ keyword in | |
339 | conjunction with the GNU/C99 extension for hexadecimal | |
340 | floating point constants and will issue a warning when | |
341 | compiling with -pedantic. */ | |
b52927b7 DD |
342 | if (nan) |
343 | dto = NAN; | |
344 | else | |
345 | dto = INFINITY; | |
346 | ||
347 | if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1)) | |
348 | dto = -dto; | |
349 | ||
350 | *to = dto; | |
351 | ||
352 | return; | |
353 | } | |
252b5132 RH |
354 | |
355 | mant_bits_left = fmt->man_len; | |
356 | mant_off = fmt->man_start; | |
357 | dto = 0.0; | |
358 | ||
08372f14 | 359 | special_exponent = exponent == 0 || (unsigned long) exponent == fmt->exp_nan; |
252b5132 RH |
360 | |
361 | /* Don't bias zero's, denorms or NaNs. */ | |
362 | if (!special_exponent) | |
363 | exponent -= fmt->exp_bias; | |
364 | ||
365 | /* Build the result algebraically. Might go infinite, underflow, etc; | |
366 | who cares. */ | |
367 | ||
368 | /* If this format uses a hidden bit, explicitly add it in now. Otherwise, | |
369 | increment the exponent by one to account for the integer bit. */ | |
370 | ||
371 | if (!special_exponent) | |
372 | { | |
373 | if (fmt->intbit == floatformat_intbit_no) | |
374 | dto = ldexp (1.0, exponent); | |
375 | else | |
376 | exponent++; | |
377 | } | |
378 | ||
379 | while (mant_bits_left > 0) | |
380 | { | |
381 | mant_bits = min (mant_bits_left, 32); | |
382 | ||
383 | mant = get_field (ufrom, fmt->byteorder, fmt->totalsize, | |
384 | mant_off, mant_bits); | |
385 | ||
b52927b7 DD |
386 | /* Handle denormalized numbers. FIXME: What should we do for |
387 | non-IEEE formats? */ | |
388 | if (exponent == 0 && mant != 0) | |
389 | dto += ldexp ((double)mant, | |
390 | (- fmt->exp_bias | |
391 | - mant_bits | |
392 | - (mant_off - fmt->man_start) | |
393 | + 1)); | |
394 | else | |
395 | dto += ldexp ((double)mant, exponent - mant_bits); | |
396 | if (exponent != 0) | |
397 | exponent -= mant_bits; | |
252b5132 RH |
398 | mant_off += mant_bits; |
399 | mant_bits_left -= mant_bits; | |
400 | } | |
401 | ||
402 | /* Negate it if negative. */ | |
403 | if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1)) | |
404 | dto = -dto; | |
405 | *to = dto; | |
406 | } | |
407 | \f | |
49b1fae4 DD |
408 | static void put_field (unsigned char *, enum floatformat_byteorders, |
409 | unsigned int, | |
410 | unsigned int, | |
411 | unsigned int, | |
412 | unsigned long); | |
252b5132 | 413 | |
3f2aacaf | 414 | /* Set a field which starts at START and is LEN bits long. DATA and |
252b5132 RH |
415 | TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ |
416 | static void | |
49b1fae4 DD |
417 | put_field (unsigned char *data, enum floatformat_byteorders order, |
418 | unsigned int total_len, unsigned int start, unsigned int len, | |
419 | unsigned long stuff_to_put) | |
252b5132 RH |
420 | { |
421 | unsigned int cur_byte; | |
422 | int cur_bitshift; | |
423 | ||
424 | /* Start at the least significant part of the field. */ | |
425 | cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT; | |
426 | if (order == floatformat_little) | |
427 | cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1; | |
428 | cur_bitshift = | |
429 | ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT; | |
430 | *(data + cur_byte) &= | |
431 | ~(((1 << ((start + len) % FLOATFORMAT_CHAR_BIT)) - 1) << (-cur_bitshift)); | |
432 | *(data + cur_byte) |= | |
433 | (stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift); | |
434 | cur_bitshift += FLOATFORMAT_CHAR_BIT; | |
435 | if (order == floatformat_little) | |
436 | ++cur_byte; | |
437 | else | |
438 | --cur_byte; | |
439 | ||
440 | /* Move towards the most significant part of the field. */ | |
08372f14 | 441 | while ((unsigned int) cur_bitshift < len) |
252b5132 RH |
442 | { |
443 | if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT) | |
444 | { | |
445 | /* This is the last byte. */ | |
446 | *(data + cur_byte) &= | |
447 | ~((1 << (len - cur_bitshift)) - 1); | |
448 | *(data + cur_byte) |= (stuff_to_put >> cur_bitshift); | |
449 | } | |
450 | else | |
451 | *(data + cur_byte) = ((stuff_to_put >> cur_bitshift) | |
452 | & ((1 << FLOATFORMAT_CHAR_BIT) - 1)); | |
453 | cur_bitshift += FLOATFORMAT_CHAR_BIT; | |
454 | if (order == floatformat_little) | |
455 | ++cur_byte; | |
456 | else | |
457 | --cur_byte; | |
458 | } | |
459 | } | |
460 | ||
461 | /* The converse: convert the double *FROM to an extended float | |
462 | and store where TO points. Neither FROM nor TO have any alignment | |
463 | restrictions. */ | |
464 | ||
465 | void | |
49b1fae4 | 466 | floatformat_from_double (const struct floatformat *fmt, |
3b6940c0 | 467 | const double *from, void *to) |
252b5132 RH |
468 | { |
469 | double dfrom; | |
470 | int exponent; | |
471 | double mant; | |
472 | unsigned int mant_bits, mant_off; | |
473 | int mant_bits_left; | |
3b6940c0 | 474 | unsigned char *uto = to; |
252b5132 | 475 | |
b52927b7 | 476 | dfrom = *from; |
252b5132 | 477 | memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT); |
b52927b7 DD |
478 | |
479 | /* If negative, set the sign bit. */ | |
480 | if (dfrom < 0) | |
481 | { | |
482 | put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1); | |
483 | dfrom = -dfrom; | |
484 | } | |
485 | ||
252b5132 | 486 | if (dfrom == 0) |
b52927b7 DD |
487 | { |
488 | /* 0.0. */ | |
489 | return; | |
490 | } | |
491 | ||
252b5132 RH |
492 | if (dfrom != dfrom) |
493 | { | |
b52927b7 | 494 | /* NaN. */ |
252b5132 RH |
495 | put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, |
496 | fmt->exp_len, fmt->exp_nan); | |
b52927b7 | 497 | /* Be sure it's not infinity, but NaN value is irrelevant. */ |
252b5132 RH |
498 | put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start, |
499 | 32, 1); | |
500 | return; | |
501 | } | |
502 | ||
b52927b7 | 503 | if (dfrom + dfrom == dfrom) |
252b5132 | 504 | { |
b52927b7 DD |
505 | /* This can only happen for an infinite value (or zero, which we |
506 | already handled above). */ | |
507 | put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, | |
508 | fmt->exp_len, fmt->exp_nan); | |
509 | return; | |
252b5132 RH |
510 | } |
511 | ||
252b5132 | 512 | mant = frexp (dfrom, &exponent); |
b52927b7 DD |
513 | if (exponent + fmt->exp_bias - 1 > 0) |
514 | put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, | |
515 | fmt->exp_len, exponent + fmt->exp_bias - 1); | |
516 | else | |
517 | { | |
518 | /* Handle a denormalized number. FIXME: What should we do for | |
519 | non-IEEE formats? */ | |
520 | put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, | |
521 | fmt->exp_len, 0); | |
522 | mant = ldexp (mant, exponent + fmt->exp_bias - 1); | |
523 | } | |
252b5132 RH |
524 | |
525 | mant_bits_left = fmt->man_len; | |
526 | mant_off = fmt->man_start; | |
527 | while (mant_bits_left > 0) | |
528 | { | |
529 | unsigned long mant_long; | |
530 | mant_bits = mant_bits_left < 32 ? mant_bits_left : 32; | |
531 | ||
532 | mant *= 4294967296.0; | |
533 | mant_long = (unsigned long)mant; | |
534 | mant -= mant_long; | |
535 | ||
b52927b7 DD |
536 | /* If the integer bit is implicit, and we are not creating a |
537 | denormalized number, then we need to discard it. */ | |
08372f14 | 538 | if ((unsigned int) mant_bits_left == fmt->man_len |
b52927b7 DD |
539 | && fmt->intbit == floatformat_intbit_no |
540 | && exponent + fmt->exp_bias - 1 > 0) | |
252b5132 RH |
541 | { |
542 | mant_long &= 0x7fffffff; | |
543 | mant_bits -= 1; | |
544 | } | |
545 | else if (mant_bits < 32) | |
546 | { | |
547 | /* The bits we want are in the most significant MANT_BITS bits of | |
548 | mant_long. Move them to the least significant. */ | |
549 | mant_long >>= 32 - mant_bits; | |
550 | } | |
551 | ||
552 | put_field (uto, fmt->byteorder, fmt->totalsize, | |
553 | mant_off, mant_bits, mant_long); | |
554 | mant_off += mant_bits; | |
555 | mant_bits_left -= mant_bits; | |
556 | } | |
557 | } | |
558 | ||
3f2aacaf DJ |
559 | /* Return non-zero iff the data at FROM is a valid number in format FMT. */ |
560 | ||
561 | int | |
3b6940c0 | 562 | floatformat_is_valid (const struct floatformat *fmt, const void *from) |
3f2aacaf | 563 | { |
5324d185 | 564 | return fmt->is_valid (fmt, from); |
3f2aacaf DJ |
565 | } |
566 | ||
252b5132 RH |
567 | |
568 | #ifdef IEEE_DEBUG | |
569 | ||
b52927b7 DD |
570 | #include <stdio.h> |
571 | ||
252b5132 RH |
572 | /* This is to be run on a host which uses IEEE floating point. */ |
573 | ||
574 | void | |
49b1fae4 | 575 | ieee_test (double n) |
252b5132 RH |
576 | { |
577 | double result; | |
252b5132 | 578 | |
3b6940c0 | 579 | floatformat_to_double (&floatformat_ieee_double_little, &n, &result); |
b52927b7 DD |
580 | if ((n != result && (! isnan (n) || ! isnan (result))) |
581 | || (n < 0 && result >= 0) | |
582 | || (n >= 0 && result < 0)) | |
252b5132 | 583 | printf ("Differ(to): %.20g -> %.20g\n", n, result); |
b52927b7 | 584 | |
3b6940c0 | 585 | floatformat_from_double (&floatformat_ieee_double_little, &n, &result); |
b52927b7 DD |
586 | if ((n != result && (! isnan (n) || ! isnan (result))) |
587 | || (n < 0 && result >= 0) | |
588 | || (n >= 0 && result < 0)) | |
252b5132 RH |
589 | printf ("Differ(from): %.20g -> %.20g\n", n, result); |
590 | ||
b52927b7 DD |
591 | #if 0 |
592 | { | |
593 | char exten[16]; | |
594 | ||
595 | floatformat_from_double (&floatformat_m68881_ext, &n, exten); | |
596 | floatformat_to_double (&floatformat_m68881_ext, exten, &result); | |
597 | if (n != result) | |
598 | printf ("Differ(to+from): %.20g -> %.20g\n", n, result); | |
599 | } | |
600 | #endif | |
252b5132 RH |
601 | |
602 | #if IEEE_DEBUG > 1 | |
603 | /* This is to be run on a host which uses 68881 format. */ | |
604 | { | |
605 | long double ex = *(long double *)exten; | |
606 | if (ex != n) | |
607 | printf ("Differ(from vs. extended): %.20g\n", n); | |
608 | } | |
609 | #endif | |
610 | } | |
611 | ||
612 | int | |
49b1fae4 | 613 | main (void) |
252b5132 | 614 | { |
b52927b7 | 615 | ieee_test (0.0); |
252b5132 RH |
616 | ieee_test (0.5); |
617 | ieee_test (256.0); | |
618 | ieee_test (0.12345); | |
619 | ieee_test (234235.78907234); | |
620 | ieee_test (-512.0); | |
621 | ieee_test (-0.004321); | |
b52927b7 DD |
622 | ieee_test (1.2E-70); |
623 | ieee_test (1.2E-316); | |
624 | ieee_test (4.9406564584124654E-324); | |
625 | ieee_test (- 4.9406564584124654E-324); | |
626 | ieee_test (- 0.0); | |
627 | ieee_test (- INFINITY); | |
628 | ieee_test (- NAN); | |
629 | ieee_test (INFINITY); | |
630 | ieee_test (NAN); | |
252b5132 RH |
631 | return 0; |
632 | } | |
633 | #endif |