Commit | Line | Data |
---|---|---|
252b5132 | 1 | /* atof_ieee.c - turn a Flonum into an IEEE floating point number |
ec2655a6 | 2 | Copyright 1987, 1992, 1994, 1996, 1997, 1998, 1999, 2000, 2001, 2005, |
20203fb9 | 3 | 2007, 2009 Free Software Foundation, Inc. |
252b5132 RH |
4 | |
5 | This file is part of GAS, the GNU Assembler. | |
6 | ||
7 | GAS is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
ec2655a6 | 9 | the Free Software Foundation; either version 3, or (at your option) |
252b5132 RH |
10 | any later version. |
11 | ||
12 | GAS 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 GAS; see the file COPYING. If not, write to the Free | |
4b4da160 NC |
19 | Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
20 | 02110-1301, USA. */ | |
252b5132 RH |
21 | |
22 | #include "as.h" | |
23 | ||
24 | /* Flonums returned here. */ | |
25 | extern FLONUM_TYPE generic_floating_point_number; | |
26 | ||
252b5132 | 27 | extern const char EXP_CHARS[]; |
2d484c7f | 28 | /* Precision in LittleNums. */ |
252b5132 | 29 | /* Don't count the gap in the m68k extended precision format. */ |
ea1562b3 NC |
30 | #define MAX_PRECISION 5 |
31 | #define F_PRECISION 2 | |
32 | #define D_PRECISION 4 | |
33 | #define X_PRECISION 5 | |
34 | #define P_PRECISION 5 | |
252b5132 | 35 | |
2d484c7f | 36 | /* Length in LittleNums of guard bits. */ |
ea1562b3 | 37 | #define GUARD 2 |
252b5132 | 38 | |
3a18fa4f | 39 | #ifndef TC_LARGEST_EXPONENT_IS_NORMAL |
580a832e | 40 | #define TC_LARGEST_EXPONENT_IS_NORMAL(PRECISION) 0 |
e103941e NC |
41 | #endif |
42 | ||
252b5132 RH |
43 | static const unsigned long mask[] = |
44 | { | |
45 | 0x00000000, | |
46 | 0x00000001, | |
47 | 0x00000003, | |
48 | 0x00000007, | |
49 | 0x0000000f, | |
50 | 0x0000001f, | |
51 | 0x0000003f, | |
52 | 0x0000007f, | |
53 | 0x000000ff, | |
54 | 0x000001ff, | |
55 | 0x000003ff, | |
56 | 0x000007ff, | |
57 | 0x00000fff, | |
58 | 0x00001fff, | |
59 | 0x00003fff, | |
60 | 0x00007fff, | |
61 | 0x0000ffff, | |
62 | 0x0001ffff, | |
63 | 0x0003ffff, | |
64 | 0x0007ffff, | |
65 | 0x000fffff, | |
66 | 0x001fffff, | |
67 | 0x003fffff, | |
68 | 0x007fffff, | |
69 | 0x00ffffff, | |
70 | 0x01ffffff, | |
71 | 0x03ffffff, | |
72 | 0x07ffffff, | |
73 | 0x0fffffff, | |
74 | 0x1fffffff, | |
75 | 0x3fffffff, | |
76 | 0x7fffffff, | |
77 | 0xffffffff, | |
78 | }; | |
79 | \f | |
252b5132 RH |
80 | static int bits_left_in_littlenum; |
81 | static int littlenums_left; | |
82 | static LITTLENUM_TYPE *littlenum_pointer; | |
83 | ||
84 | static int | |
ea1562b3 | 85 | next_bits (int number_of_bits) |
252b5132 RH |
86 | { |
87 | int return_value; | |
88 | ||
89 | if (!littlenums_left) | |
ea1562b3 NC |
90 | return 0; |
91 | ||
252b5132 RH |
92 | if (number_of_bits >= bits_left_in_littlenum) |
93 | { | |
94 | return_value = mask[bits_left_in_littlenum] & *littlenum_pointer; | |
95 | number_of_bits -= bits_left_in_littlenum; | |
96 | return_value <<= number_of_bits; | |
97 | ||
98 | if (--littlenums_left) | |
99 | { | |
100 | bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits; | |
101 | --littlenum_pointer; | |
2d484c7f KH |
102 | return_value |= |
103 | (*littlenum_pointer >> bits_left_in_littlenum) | |
104 | & mask[number_of_bits]; | |
252b5132 RH |
105 | } |
106 | } | |
107 | else | |
108 | { | |
109 | bits_left_in_littlenum -= number_of_bits; | |
2d484c7f KH |
110 | return_value = |
111 | mask[number_of_bits] & (*littlenum_pointer >> bits_left_in_littlenum); | |
252b5132 | 112 | } |
2d484c7f | 113 | return return_value; |
252b5132 RH |
114 | } |
115 | ||
2d484c7f KH |
116 | /* Num had better be less than LITTLENUM_NUMBER_OF_BITS. */ |
117 | ||
252b5132 | 118 | static void |
ea1562b3 | 119 | unget_bits (int num) |
252b5132 RH |
120 | { |
121 | if (!littlenums_left) | |
122 | { | |
123 | ++littlenum_pointer; | |
124 | ++littlenums_left; | |
125 | bits_left_in_littlenum = num; | |
126 | } | |
127 | else if (bits_left_in_littlenum + num > LITTLENUM_NUMBER_OF_BITS) | |
128 | { | |
2d484c7f KH |
129 | bits_left_in_littlenum = |
130 | num - (LITTLENUM_NUMBER_OF_BITS - bits_left_in_littlenum); | |
252b5132 RH |
131 | ++littlenum_pointer; |
132 | ++littlenums_left; | |
133 | } | |
134 | else | |
135 | bits_left_in_littlenum += num; | |
136 | } | |
137 | ||
138 | static void | |
ea1562b3 | 139 | make_invalid_floating_point_number (LITTLENUM_TYPE *words) |
252b5132 RH |
140 | { |
141 | as_bad (_("cannot create floating-point number")); | |
2d484c7f KH |
142 | /* Zero the leftmost bit. */ |
143 | words[0] = (LITTLENUM_TYPE) ((unsigned) -1) >> 1; | |
252b5132 RH |
144 | words[1] = (LITTLENUM_TYPE) -1; |
145 | words[2] = (LITTLENUM_TYPE) -1; | |
146 | words[3] = (LITTLENUM_TYPE) -1; | |
147 | words[4] = (LITTLENUM_TYPE) -1; | |
148 | words[5] = (LITTLENUM_TYPE) -1; | |
149 | } | |
150 | \f | |
2d484c7f KH |
151 | /* Warning: This returns 16-bit LITTLENUMs. It is up to the caller to |
152 | figure out any alignment problems and to conspire for the | |
153 | bytes/word to be emitted in the right order. Bigendians beware! */ | |
252b5132 RH |
154 | |
155 | /* Note that atof-ieee always has X and P precisions enabled. it is up | |
156 | to md_atof to filter them out if the target machine does not support | |
157 | them. */ | |
158 | ||
2d484c7f KH |
159 | /* Returns pointer past text consumed. */ |
160 | ||
252b5132 | 161 | char * |
ea1562b3 | 162 | atof_ieee (char *str, /* Text to convert to binary. */ |
499ac353 | 163 | int what_kind, /* 'd', 'f', 'x', 'p'. */ |
ea1562b3 | 164 | LITTLENUM_TYPE *words) /* Build the binary here. */ |
252b5132 | 165 | { |
2d484c7f KH |
166 | /* Extra bits for zeroed low-order bits. |
167 | The 1st MAX_PRECISION are zeroed, the last contain flonum bits. */ | |
252b5132 RH |
168 | static LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD]; |
169 | char *return_value; | |
2d484c7f | 170 | /* Number of 16-bit words in the format. */ |
252b5132 RH |
171 | int precision; |
172 | long exponent_bits; | |
173 | FLONUM_TYPE save_gen_flonum; | |
174 | ||
175 | /* We have to save the generic_floating_point_number because it | |
176 | contains storage allocation about the array of LITTLENUMs where | |
177 | the value is actually stored. We will allocate our own array of | |
178 | littlenums below, but have to restore the global one on exit. */ | |
179 | save_gen_flonum = generic_floating_point_number; | |
180 | ||
181 | return_value = str; | |
182 | generic_floating_point_number.low = bits + MAX_PRECISION; | |
183 | generic_floating_point_number.high = NULL; | |
184 | generic_floating_point_number.leader = NULL; | |
185 | generic_floating_point_number.exponent = 0; | |
186 | generic_floating_point_number.sign = '\0'; | |
187 | ||
188 | /* Use more LittleNums than seems necessary: the highest flonum may | |
2d484c7f | 189 | have 15 leading 0 bits, so could be useless. */ |
252b5132 RH |
190 | |
191 | memset (bits, '\0', sizeof (LITTLENUM_TYPE) * MAX_PRECISION); | |
192 | ||
193 | switch (what_kind) | |
194 | { | |
195 | case 'f': | |
196 | case 'F': | |
197 | case 's': | |
198 | case 'S': | |
199 | precision = F_PRECISION; | |
200 | exponent_bits = 8; | |
201 | break; | |
202 | ||
203 | case 'd': | |
204 | case 'D': | |
205 | case 'r': | |
206 | case 'R': | |
207 | precision = D_PRECISION; | |
208 | exponent_bits = 11; | |
209 | break; | |
210 | ||
211 | case 'x': | |
212 | case 'X': | |
213 | case 'e': | |
214 | case 'E': | |
215 | precision = X_PRECISION; | |
216 | exponent_bits = 15; | |
217 | break; | |
218 | ||
219 | case 'p': | |
220 | case 'P': | |
252b5132 RH |
221 | precision = P_PRECISION; |
222 | exponent_bits = -1; | |
223 | break; | |
224 | ||
225 | default: | |
226 | make_invalid_floating_point_number (words); | |
227 | return (NULL); | |
228 | } | |
229 | ||
230 | generic_floating_point_number.high | |
231 | = generic_floating_point_number.low + precision - 1 + GUARD; | |
232 | ||
233 | if (atof_generic (&return_value, ".", EXP_CHARS, | |
234 | &generic_floating_point_number)) | |
235 | { | |
236 | make_invalid_floating_point_number (words); | |
ea1562b3 | 237 | return NULL; |
252b5132 RH |
238 | } |
239 | gen_to_words (words, precision, exponent_bits); | |
240 | ||
241 | /* Restore the generic_floating_point_number's storage alloc (and | |
242 | everything else). */ | |
243 | generic_floating_point_number = save_gen_flonum; | |
244 | ||
245 | return return_value; | |
246 | } | |
247 | ||
248 | /* Turn generic_floating_point_number into a real float/double/extended. */ | |
2d484c7f | 249 | |
252b5132 | 250 | int |
ea1562b3 | 251 | gen_to_words (LITTLENUM_TYPE *words, int precision, long exponent_bits) |
252b5132 RH |
252 | { |
253 | int return_value = 0; | |
254 | ||
255 | long exponent_1; | |
256 | long exponent_2; | |
257 | long exponent_3; | |
258 | long exponent_4; | |
259 | int exponent_skippage; | |
260 | LITTLENUM_TYPE word1; | |
261 | LITTLENUM_TYPE *lp; | |
262 | LITTLENUM_TYPE *words_end; | |
263 | ||
264 | words_end = words + precision; | |
265 | #ifdef TC_M68K | |
266 | if (precision == X_PRECISION) | |
267 | /* On the m68k the extended precision format has a gap of 16 bits | |
268 | between the exponent and the mantissa. */ | |
269 | words_end++; | |
270 | #endif | |
271 | ||
272 | if (generic_floating_point_number.low > generic_floating_point_number.leader) | |
273 | { | |
2d484c7f | 274 | /* 0.0e0 seen. */ |
252b5132 RH |
275 | if (generic_floating_point_number.sign == '+') |
276 | words[0] = 0x0000; | |
277 | else | |
278 | words[0] = 0x8000; | |
279 | memset (&words[1], '\0', | |
280 | (words_end - words - 1) * sizeof (LITTLENUM_TYPE)); | |
2d484c7f | 281 | return return_value; |
252b5132 RH |
282 | } |
283 | ||
2d484c7f | 284 | /* NaN: Do the right thing. */ |
252b5132 RH |
285 | if (generic_floating_point_number.sign == 0) |
286 | { | |
580a832e | 287 | if (TC_LARGEST_EXPONENT_IS_NORMAL (precision)) |
20203fb9 | 288 | as_warn (_("NaNs are not supported by this target\n")); |
252b5132 RH |
289 | if (precision == F_PRECISION) |
290 | { | |
291 | words[0] = 0x7fff; | |
292 | words[1] = 0xffff; | |
293 | } | |
294 | else if (precision == X_PRECISION) | |
295 | { | |
296 | #ifdef TC_M68K | |
297 | words[0] = 0x7fff; | |
298 | words[1] = 0; | |
299 | words[2] = 0xffff; | |
300 | words[3] = 0xffff; | |
301 | words[4] = 0xffff; | |
302 | words[5] = 0xffff; | |
2d484c7f | 303 | #else /* ! TC_M68K */ |
252b5132 RH |
304 | #ifdef TC_I386 |
305 | words[0] = 0xffff; | |
306 | words[1] = 0xc000; | |
307 | words[2] = 0; | |
308 | words[3] = 0; | |
309 | words[4] = 0; | |
2d484c7f | 310 | #else /* ! TC_I386 */ |
252b5132 | 311 | abort (); |
2d484c7f KH |
312 | #endif /* ! TC_I386 */ |
313 | #endif /* ! TC_M68K */ | |
252b5132 RH |
314 | } |
315 | else | |
316 | { | |
317 | words[0] = 0x7fff; | |
318 | words[1] = 0xffff; | |
319 | words[2] = 0xffff; | |
320 | words[3] = 0xffff; | |
321 | } | |
322 | return return_value; | |
323 | } | |
324 | else if (generic_floating_point_number.sign == 'P') | |
325 | { | |
580a832e | 326 | if (TC_LARGEST_EXPONENT_IS_NORMAL (precision)) |
20203fb9 | 327 | as_warn (_("Infinities are not supported by this target\n")); |
e103941e | 328 | |
2d484c7f | 329 | /* +INF: Do the right thing. */ |
252b5132 RH |
330 | if (precision == F_PRECISION) |
331 | { | |
332 | words[0] = 0x7f80; | |
333 | words[1] = 0; | |
334 | } | |
335 | else if (precision == X_PRECISION) | |
336 | { | |
337 | #ifdef TC_M68K | |
338 | words[0] = 0x7fff; | |
339 | words[1] = 0; | |
340 | words[2] = 0; | |
341 | words[3] = 0; | |
342 | words[4] = 0; | |
343 | words[5] = 0; | |
2d484c7f | 344 | #else /* ! TC_M68K */ |
252b5132 RH |
345 | #ifdef TC_I386 |
346 | words[0] = 0x7fff; | |
347 | words[1] = 0x8000; | |
348 | words[2] = 0; | |
349 | words[3] = 0; | |
350 | words[4] = 0; | |
2d484c7f | 351 | #else /* ! TC_I386 */ |
252b5132 | 352 | abort (); |
2d484c7f KH |
353 | #endif /* ! TC_I386 */ |
354 | #endif /* ! TC_M68K */ | |
252b5132 RH |
355 | } |
356 | else | |
357 | { | |
358 | words[0] = 0x7ff0; | |
359 | words[1] = 0; | |
360 | words[2] = 0; | |
361 | words[3] = 0; | |
362 | } | |
2d484c7f | 363 | return return_value; |
252b5132 RH |
364 | } |
365 | else if (generic_floating_point_number.sign == 'N') | |
366 | { | |
580a832e | 367 | if (TC_LARGEST_EXPONENT_IS_NORMAL (precision)) |
20203fb9 | 368 | as_warn (_("Infinities are not supported by this target\n")); |
e103941e | 369 | |
2d484c7f | 370 | /* Negative INF. */ |
252b5132 RH |
371 | if (precision == F_PRECISION) |
372 | { | |
373 | words[0] = 0xff80; | |
374 | words[1] = 0x0; | |
375 | } | |
376 | else if (precision == X_PRECISION) | |
377 | { | |
378 | #ifdef TC_M68K | |
379 | words[0] = 0xffff; | |
380 | words[1] = 0; | |
381 | words[2] = 0; | |
382 | words[3] = 0; | |
383 | words[4] = 0; | |
384 | words[5] = 0; | |
2d484c7f | 385 | #else /* ! TC_M68K */ |
252b5132 RH |
386 | #ifdef TC_I386 |
387 | words[0] = 0xffff; | |
388 | words[1] = 0x8000; | |
389 | words[2] = 0; | |
390 | words[3] = 0; | |
391 | words[4] = 0; | |
2d484c7f | 392 | #else /* ! TC_I386 */ |
252b5132 | 393 | abort (); |
2d484c7f KH |
394 | #endif /* ! TC_I386 */ |
395 | #endif /* ! TC_M68K */ | |
252b5132 RH |
396 | } |
397 | else | |
398 | { | |
399 | words[0] = 0xfff0; | |
400 | words[1] = 0x0; | |
401 | words[2] = 0x0; | |
402 | words[3] = 0x0; | |
403 | } | |
2d484c7f | 404 | return return_value; |
252b5132 | 405 | } |
2d484c7f KH |
406 | |
407 | /* The floating point formats we support have: | |
408 | Bit 15 is sign bit. | |
409 | Bits 14:n are excess-whatever exponent. | |
410 | Bits n-1:0 (if any) are most significant bits of fraction. | |
411 | Bits 15:0 of the next word(s) are the next most significant bits. | |
412 | ||
413 | So we need: number of bits of exponent, number of bits of | |
414 | mantissa. */ | |
252b5132 RH |
415 | bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS; |
416 | littlenum_pointer = generic_floating_point_number.leader; | |
417 | littlenums_left = (1 | |
418 | + generic_floating_point_number.leader | |
419 | - generic_floating_point_number.low); | |
2d484c7f KH |
420 | |
421 | /* Seek (and forget) 1st significant bit. */ | |
252b5132 RH |
422 | for (exponent_skippage = 0; !next_bits (1); ++exponent_skippage);; |
423 | exponent_1 = (generic_floating_point_number.exponent | |
424 | + generic_floating_point_number.leader | |
425 | + 1 | |
426 | - generic_floating_point_number.low); | |
2d484c7f | 427 | |
252b5132 | 428 | /* Radix LITTLENUM_RADIX, point just higher than |
2d484c7f | 429 | generic_floating_point_number.leader. */ |
252b5132 | 430 | exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS; |
2d484c7f KH |
431 | |
432 | /* Radix 2. */ | |
252b5132 | 433 | exponent_3 = exponent_2 - exponent_skippage; |
2d484c7f KH |
434 | |
435 | /* Forget leading zeros, forget 1st bit. */ | |
252b5132 | 436 | exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2); |
252b5132 | 437 | |
2d484c7f | 438 | /* Offset exponent. */ |
252b5132 RH |
439 | lp = words; |
440 | ||
2d484c7f | 441 | /* Word 1. Sign, exponent and perhaps high bits. */ |
252b5132 RH |
442 | word1 = ((generic_floating_point_number.sign == '+') |
443 | ? 0 | |
444 | : (1 << (LITTLENUM_NUMBER_OF_BITS - 1))); | |
445 | ||
2d484c7f | 446 | /* Assume 2's complement integers. */ |
252b5132 RH |
447 | if (exponent_4 <= 0) |
448 | { | |
449 | int prec_bits; | |
450 | int num_bits; | |
451 | ||
452 | unget_bits (1); | |
453 | num_bits = -exponent_4; | |
2d484c7f KH |
454 | prec_bits = |
455 | LITTLENUM_NUMBER_OF_BITS * precision - (exponent_bits + 1 + num_bits); | |
252b5132 RH |
456 | #ifdef TC_I386 |
457 | if (precision == X_PRECISION && exponent_bits == 15) | |
458 | { | |
459 | /* On the i386 a denormalized extended precision float is | |
460 | shifted down by one, effectively decreasing the exponent | |
461 | bias by one. */ | |
462 | prec_bits -= 1; | |
463 | num_bits += 1; | |
464 | } | |
465 | #endif | |
466 | ||
467 | if (num_bits >= LITTLENUM_NUMBER_OF_BITS - exponent_bits) | |
468 | { | |
2d484c7f | 469 | /* Bigger than one littlenum. */ |
252b5132 RH |
470 | num_bits -= (LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits; |
471 | *lp++ = word1; | |
2d484c7f KH |
472 | if (num_bits + exponent_bits + 1 |
473 | > precision * LITTLENUM_NUMBER_OF_BITS) | |
252b5132 | 474 | { |
2d484c7f | 475 | /* Exponent overflow. */ |
252b5132 | 476 | make_invalid_floating_point_number (words); |
2d484c7f | 477 | return return_value; |
252b5132 RH |
478 | } |
479 | #ifdef TC_M68K | |
480 | if (precision == X_PRECISION && exponent_bits == 15) | |
481 | *lp++ = 0; | |
482 | #endif | |
483 | while (num_bits >= LITTLENUM_NUMBER_OF_BITS) | |
484 | { | |
485 | num_bits -= LITTLENUM_NUMBER_OF_BITS; | |
486 | *lp++ = 0; | |
487 | } | |
488 | if (num_bits) | |
489 | *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - (num_bits)); | |
490 | } | |
491 | else | |
492 | { | |
493 | if (precision == X_PRECISION && exponent_bits == 15) | |
494 | { | |
495 | *lp++ = word1; | |
496 | #ifdef TC_M68K | |
497 | *lp++ = 0; | |
498 | #endif | |
499 | *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - num_bits); | |
500 | } | |
501 | else | |
502 | { | |
2d484c7f KH |
503 | word1 |= next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) |
504 | - (exponent_bits + num_bits)); | |
252b5132 RH |
505 | *lp++ = word1; |
506 | } | |
507 | } | |
508 | while (lp < words_end) | |
509 | *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS); | |
510 | ||
2d484c7f | 511 | /* Round the mantissa up, but don't change the number. */ |
252b5132 RH |
512 | if (next_bits (1)) |
513 | { | |
514 | --lp; | |
19b34177 | 515 | if (prec_bits >= LITTLENUM_NUMBER_OF_BITS) |
252b5132 RH |
516 | { |
517 | int n = 0; | |
518 | int tmp_bits; | |
519 | ||
520 | n = 0; | |
521 | tmp_bits = prec_bits; | |
522 | while (tmp_bits > LITTLENUM_NUMBER_OF_BITS) | |
523 | { | |
524 | if (lp[n] != (LITTLENUM_TYPE) - 1) | |
525 | break; | |
526 | --n; | |
527 | tmp_bits -= LITTLENUM_NUMBER_OF_BITS; | |
528 | } | |
19b34177 AS |
529 | if (tmp_bits > LITTLENUM_NUMBER_OF_BITS |
530 | || (lp[n] & mask[tmp_bits]) != mask[tmp_bits] | |
531 | || (prec_bits != (precision * LITTLENUM_NUMBER_OF_BITS | |
532 | - exponent_bits - 1) | |
533 | #ifdef TC_I386 | |
534 | /* An extended precision float with only the integer | |
535 | bit set would be invalid. That must be converted | |
536 | to the smallest normalized number. */ | |
537 | && !(precision == X_PRECISION | |
538 | && prec_bits == (precision * LITTLENUM_NUMBER_OF_BITS | |
539 | - exponent_bits - 2)) | |
540 | #endif | |
541 | )) | |
252b5132 RH |
542 | { |
543 | unsigned long carry; | |
544 | ||
545 | for (carry = 1; carry && (lp >= words); lp--) | |
546 | { | |
547 | carry = *lp + carry; | |
548 | *lp = carry; | |
549 | carry >>= LITTLENUM_NUMBER_OF_BITS; | |
550 | } | |
551 | } | |
552 | else | |
553 | { | |
554 | /* This is an overflow of the denormal numbers. We | |
555 | need to forget what we have produced, and instead | |
556 | generate the smallest normalized number. */ | |
557 | lp = words; | |
558 | word1 = ((generic_floating_point_number.sign == '+') | |
559 | ? 0 | |
560 | : (1 << (LITTLENUM_NUMBER_OF_BITS - 1))); | |
561 | word1 |= (1 | |
562 | << ((LITTLENUM_NUMBER_OF_BITS - 1) | |
563 | - exponent_bits)); | |
564 | *lp++ = word1; | |
19b34177 AS |
565 | #ifdef TC_I386 |
566 | /* Set the integer bit in the extended precision format. | |
567 | This cannot happen on the m68k where the mantissa | |
568 | just overflows into the integer bit above. */ | |
569 | if (precision == X_PRECISION) | |
570 | *lp++ = 1 << (LITTLENUM_NUMBER_OF_BITS - 1); | |
571 | #endif | |
252b5132 RH |
572 | while (lp < words_end) |
573 | *lp++ = 0; | |
574 | } | |
575 | } | |
19b34177 | 576 | else |
252b5132 RH |
577 | *lp += 1; |
578 | } | |
579 | ||
580 | return return_value; | |
581 | } | |
e103941e | 582 | else if ((unsigned long) exponent_4 > mask[exponent_bits] |
580a832e | 583 | || (! TC_LARGEST_EXPONENT_IS_NORMAL (precision) |
e103941e | 584 | && (unsigned long) exponent_4 == mask[exponent_bits])) |
252b5132 | 585 | { |
2d484c7f KH |
586 | /* Exponent overflow. Lose immediately. */ |
587 | ||
588 | /* We leave return_value alone: admit we read the | |
589 | number, but return a floating exception | |
590 | because we can't encode the number. */ | |
252b5132 RH |
591 | make_invalid_floating_point_number (words); |
592 | return return_value; | |
593 | } | |
594 | else | |
595 | { | |
596 | word1 |= (exponent_4 << ((LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits)) | |
597 | | next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits); | |
598 | } | |
599 | ||
600 | *lp++ = word1; | |
601 | ||
602 | /* X_PRECISION is special: on the 68k, it has 16 bits of zero in the | |
2d484c7f | 603 | middle. Either way, it is then followed by a 1 bit. */ |
252b5132 RH |
604 | if (exponent_bits == 15 && precision == X_PRECISION) |
605 | { | |
606 | #ifdef TC_M68K | |
607 | *lp++ = 0; | |
608 | #endif | |
609 | *lp++ = (1 << (LITTLENUM_NUMBER_OF_BITS - 1) | |
610 | | next_bits (LITTLENUM_NUMBER_OF_BITS - 1)); | |
611 | } | |
612 | ||
2d484c7f | 613 | /* The rest of the words are just mantissa bits. */ |
252b5132 RH |
614 | while (lp < words_end) |
615 | *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS); | |
616 | ||
617 | if (next_bits (1)) | |
618 | { | |
619 | unsigned long carry; | |
2d484c7f KH |
620 | /* Since the NEXT bit is a 1, round UP the mantissa. |
621 | The cunning design of these hidden-1 floats permits | |
622 | us to let the mantissa overflow into the exponent, and | |
623 | it 'does the right thing'. However, we lose if the | |
624 | highest-order bit of the lowest-order word flips. | |
625 | Is that clear? */ | |
252b5132 RH |
626 | |
627 | /* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2) | |
628 | Please allow at least 1 more bit in carry than is in a LITTLENUM. | |
629 | We need that extra bit to hold a carry during a LITTLENUM carry | |
630 | propagation. Another extra bit (kept 0) will assure us that we | |
631 | don't get a sticky sign bit after shifting right, and that | |
632 | permits us to propagate the carry without any masking of bits. | |
633 | #endif */ | |
44877466 | 634 | for (carry = 1, lp--; carry; lp--) |
252b5132 RH |
635 | { |
636 | carry = *lp + carry; | |
637 | *lp = carry; | |
638 | carry >>= LITTLENUM_NUMBER_OF_BITS; | |
44877466 ILT |
639 | if (lp == words) |
640 | break; | |
252b5132 RH |
641 | } |
642 | if (precision == X_PRECISION && exponent_bits == 15) | |
643 | { | |
644 | /* Extended precision numbers have an explicit integer bit | |
645 | that we may have to restore. */ | |
646 | if (lp == words) | |
647 | { | |
648 | #ifdef TC_M68K | |
649 | /* On the m68k there is a gap of 16 bits. We must | |
2d484c7f | 650 | explicitly propagate the carry into the exponent. */ |
252b5132 RH |
651 | words[0] += words[1]; |
652 | words[1] = 0; | |
653 | lp++; | |
654 | #endif | |
2d484c7f | 655 | /* Put back the integer bit. */ |
252b5132 RH |
656 | lp[1] |= 1 << (LITTLENUM_NUMBER_OF_BITS - 1); |
657 | } | |
2d484c7f | 658 | } |
252b5132 RH |
659 | if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1))) |
660 | { | |
2d484c7f KH |
661 | /* We leave return_value alone: admit we read the number, |
662 | but return a floating exception because we can't encode | |
663 | the number. */ | |
252b5132 | 664 | *words &= ~(1 << (LITTLENUM_NUMBER_OF_BITS - 1)); |
252b5132 RH |
665 | } |
666 | } | |
2d484c7f | 667 | return return_value; |
252b5132 RH |
668 | } |
669 | ||
252b5132 RH |
670 | #ifdef TEST |
671 | char * | |
672 | print_gen (gen) | |
673 | FLONUM_TYPE *gen; | |
674 | { | |
675 | FLONUM_TYPE f; | |
676 | LITTLENUM_TYPE arr[10]; | |
677 | double dv; | |
678 | float fv; | |
679 | static char sbuf[40]; | |
680 | ||
681 | if (gen) | |
682 | { | |
683 | f = generic_floating_point_number; | |
684 | generic_floating_point_number = *gen; | |
685 | } | |
686 | gen_to_words (&arr[0], 4, 11); | |
687 | memcpy (&dv, &arr[0], sizeof (double)); | |
688 | sprintf (sbuf, "%x %x %x %x %.14G ", arr[0], arr[1], arr[2], arr[3], dv); | |
689 | gen_to_words (&arr[0], 2, 8); | |
690 | memcpy (&fv, &arr[0], sizeof (float)); | |
691 | sprintf (sbuf + strlen (sbuf), "%x %x %.12g\n", arr[0], arr[1], fv); | |
692 | ||
693 | if (gen) | |
2d484c7f | 694 | generic_floating_point_number = f; |
252b5132 RH |
695 | |
696 | return (sbuf); | |
697 | } | |
499ac353 NC |
698 | #endif |
699 | ||
700 | extern const char FLT_CHARS[]; | |
701 | #define MAX_LITTLENUMS 6 | |
702 | ||
703 | /* This is a utility function called from various tc-*.c files. It | |
704 | is here in order to reduce code duplication. | |
705 | ||
706 | Turn a string at input_line_pointer into a floating point constant | |
707 | of type TYPE (a character found in the FLT_CHARS macro), and store | |
708 | it as LITTLENUMS in the bytes buffer LITP. The number of chars | |
709 | emitted is stored in *SIZEP. BIG_WORDIAN is TRUE if the littlenums | |
710 | should be emitted most significant littlenum first. | |
711 | ||
712 | An error message is returned, or a NULL pointer if everything went OK. */ | |
713 | ||
714 | char * | |
715 | ieee_md_atof (int type, | |
716 | char *litP, | |
717 | int *sizeP, | |
718 | bfd_boolean big_wordian) | |
719 | { | |
720 | LITTLENUM_TYPE words[MAX_LITTLENUMS]; | |
721 | LITTLENUM_TYPE *wordP; | |
722 | char *t; | |
723 | int prec = 0; | |
252b5132 | 724 | |
499ac353 NC |
725 | if (strchr (FLT_CHARS, type) != NULL) |
726 | { | |
727 | switch (type) | |
728 | { | |
729 | case 'f': | |
730 | case 'F': | |
731 | case 's': | |
732 | case 'S': | |
733 | prec = F_PRECISION; | |
734 | break; | |
735 | ||
736 | case 'd': | |
737 | case 'D': | |
738 | case 'r': | |
739 | case 'R': | |
740 | prec = D_PRECISION; | |
741 | break; | |
742 | ||
743 | case 't': | |
744 | case 'T': | |
745 | prec = X_PRECISION; | |
746 | type = 'x'; /* This is what atof_ieee() understands. */ | |
747 | break; | |
748 | ||
749 | case 'x': | |
750 | case 'X': | |
751 | case 'p': | |
752 | case 'P': | |
753 | #ifdef TC_M68K | |
754 | /* Note: on the m68k there is a gap of 16 bits (one littlenum) | |
755 | between the exponent and mantissa. Hence the precision is | |
756 | 6 and not 5. */ | |
757 | prec = P_PRECISION + 1; | |
758 | #else | |
759 | prec = P_PRECISION; | |
252b5132 | 760 | #endif |
499ac353 NC |
761 | break; |
762 | ||
763 | default: | |
764 | break; | |
765 | } | |
766 | } | |
767 | /* The 'f' and 'd' types are always recognised, even if the target has | |
768 | not put them into the FLT_CHARS macro. This is because the 'f' type | |
769 | can come from the .dc.s, .dcb.s, .float or .single pseudo-ops and the | |
770 | 'd' type from the .dc.d, .dbc.d or .double pseudo-ops. | |
771 | ||
772 | The 'x' type is not implicitly recongised however, even though it can | |
773 | be generated by the .dc.x and .dbc.x pseudo-ops because not all targets | |
774 | can support floating point values that big. ie the target has to | |
775 | explicitly allow them by putting them into FLT_CHARS. */ | |
776 | else if (type == 'f') | |
777 | prec = F_PRECISION; | |
778 | else if (type == 'd') | |
779 | prec = D_PRECISION; | |
780 | ||
781 | if (prec == 0) | |
782 | { | |
783 | *sizeP = 0; | |
784 | return _("Unrecognized or unsupported floating point constant"); | |
785 | } | |
786 | ||
9c2799c2 | 787 | gas_assert (prec <= MAX_LITTLENUMS); |
499ac353 NC |
788 | |
789 | t = atof_ieee (input_line_pointer, type, words); | |
790 | if (t) | |
791 | input_line_pointer = t; | |
792 | ||
793 | *sizeP = prec * sizeof (LITTLENUM_TYPE); | |
794 | ||
795 | if (big_wordian) | |
796 | { | |
797 | for (wordP = words; prec --;) | |
798 | { | |
799 | md_number_to_chars (litP, (valueT) (* wordP ++), sizeof (LITTLENUM_TYPE)); | |
800 | litP += sizeof (LITTLENUM_TYPE); | |
801 | } | |
802 | } | |
803 | else | |
804 | { | |
805 | for (wordP = words + prec; prec --;) | |
806 | { | |
807 | md_number_to_chars (litP, (valueT) (* -- wordP), sizeof (LITTLENUM_TYPE)); | |
808 | litP += sizeof (LITTLENUM_TYPE); | |
809 | } | |
810 | } | |
811 | ||
812 | return NULL; | |
813 | } |