1 /* Decimal floating point support.
2 Copyright (C) 2005-2020 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "tm.h"
24 #include "tree.h"
25 #include "dfp.h"
26
27 /* The order of the following headers is important for making sure
28 decNumber structure is large enough to hold decimal128 digits. */
29
30 #include "decimal128.h"
31 #include "decimal64.h"
32 #include "decimal32.h"
33
34 #ifndef WORDS_BIGENDIAN
35 #define WORDS_BIGENDIAN 0
36 #endif
37
38 /* Initialize R (a real with the decimal flag set) from DN. Can
39 utilize status passed in via CONTEXT, if a previous operation had
40 interesting status. */
41
42 static void
decimal_from_decnumber(REAL_VALUE_TYPE * r,decNumber * dn,decContext * context)43 decimal_from_decnumber (REAL_VALUE_TYPE *r, decNumber *dn, decContext *context)
44 {
45 memset (r, 0, sizeof (REAL_VALUE_TYPE));
46
47 r->cl = rvc_normal;
48 if (decNumberIsNaN (dn))
49 r->cl = rvc_nan;
50 if (decNumberIsInfinite (dn))
51 r->cl = rvc_inf;
52 if (context->status & DEC_Overflow)
53 r->cl = rvc_inf;
54 if (decNumberIsNegative (dn))
55 r->sign = 1;
56 r->decimal = 1;
57
58 if (r->cl != rvc_normal)
59 return;
60
61 decContextDefault (context, DEC_INIT_DECIMAL128);
62 context->traps = 0;
63
64 decimal128FromNumber ((decimal128 *) r->sig, dn, context);
65 }
66
67 /* Create decimal encoded R from string S. */
68
69 void
decimal_real_from_string(REAL_VALUE_TYPE * r,const char * s)70 decimal_real_from_string (REAL_VALUE_TYPE *r, const char *s)
71 {
72 decNumber dn;
73 decContext set;
74 decContextDefault (&set, DEC_INIT_DECIMAL128);
75 set.traps = 0;
76
77 decNumberFromString (&dn, s, &set);
78
79 /* It would be more efficient to store directly in decNumber format,
80 but that is impractical from current data structure size.
81 Encoding as a decimal128 is much more compact. */
82 decimal_from_decnumber (r, &dn, &set);
83 }
84
85 /* Initialize a decNumber from a REAL_VALUE_TYPE. */
86
87 static void
decimal_to_decnumber(const REAL_VALUE_TYPE * r,decNumber * dn)88 decimal_to_decnumber (const REAL_VALUE_TYPE *r, decNumber *dn)
89 {
90 decContext set;
91 decContextDefault (&set, DEC_INIT_DECIMAL128);
92 set.traps = 0;
93
94 switch (r->cl)
95 {
96 case rvc_zero:
97 decNumberZero (dn);
98 break;
99 case rvc_inf:
100 decNumberFromString (dn, "Infinity", &set);
101 break;
102 case rvc_nan:
103 if (r->signalling)
104 decNumberFromString (dn, "snan", &set);
105 else
106 decNumberFromString (dn, "nan", &set);
107 break;
108 case rvc_normal:
109 if (!r->decimal)
110 {
111 /* dconst{1,2,m1,half} are used in various places in
112 the middle-end and optimizers, allow them here
113 as an exception by converting them to decimal. */
114 if (memcmp (r, &dconst1, sizeof (*r)) == 0)
115 {
116 decNumberFromString (dn, "1", &set);
117 break;
118 }
119 if (memcmp (r, &dconst2, sizeof (*r)) == 0)
120 {
121 decNumberFromString (dn, "2", &set);
122 break;
123 }
124 if (memcmp (r, &dconstm1, sizeof (*r)) == 0)
125 {
126 decNumberFromString (dn, "-1", &set);
127 break;
128 }
129 if (memcmp (r, &dconsthalf, sizeof (*r)) == 0)
130 {
131 decNumberFromString (dn, "0.5", &set);
132 break;
133 }
134 gcc_unreachable ();
135 }
136 decimal128ToNumber ((const decimal128 *) r->sig, dn);
137 break;
138 default:
139 gcc_unreachable ();
140 }
141
142 /* Fix up sign bit. */
143 if (r->sign != decNumberIsNegative (dn))
144 dn->bits ^= DECNEG;
145 }
146
147 /* Encode a real into an IEEE 754 decimal32 type. */
148
149 void
encode_decimal32(const struct real_format * fmt ATTRIBUTE_UNUSED,long * buf,const REAL_VALUE_TYPE * r)150 encode_decimal32 (const struct real_format *fmt ATTRIBUTE_UNUSED,
151 long *buf, const REAL_VALUE_TYPE *r)
152 {
153 decNumber dn;
154 decimal32 d32;
155 decContext set;
156 int32_t image;
157
158 decContextDefault (&set, DEC_INIT_DECIMAL128);
159 set.traps = 0;
160
161 decimal_to_decnumber (r, &dn);
162 decimal32FromNumber (&d32, &dn, &set);
163
164 memcpy (&image, d32.bytes, sizeof (int32_t));
165 buf[0] = image;
166 }
167
168 /* Decode an IEEE 754 decimal32 type into a real. */
169
170 void
decode_decimal32(const struct real_format * fmt ATTRIBUTE_UNUSED,REAL_VALUE_TYPE * r,const long * buf)171 decode_decimal32 (const struct real_format *fmt ATTRIBUTE_UNUSED,
172 REAL_VALUE_TYPE *r, const long *buf)
173 {
174 decNumber dn;
175 decimal32 d32;
176 decContext set;
177 int32_t image;
178
179 decContextDefault (&set, DEC_INIT_DECIMAL128);
180 set.traps = 0;
181
182 image = buf[0];
183 memcpy (&d32.bytes, &image, sizeof (int32_t));
184
185 decimal32ToNumber (&d32, &dn);
186 decimal_from_decnumber (r, &dn, &set);
187 }
188
189 /* Encode a real into an IEEE 754 decimal64 type. */
190
191 void
encode_decimal64(const struct real_format * fmt ATTRIBUTE_UNUSED,long * buf,const REAL_VALUE_TYPE * r)192 encode_decimal64 (const struct real_format *fmt ATTRIBUTE_UNUSED,
193 long *buf, const REAL_VALUE_TYPE *r)
194 {
195 decNumber dn;
196 decimal64 d64;
197 decContext set;
198 int32_t image;
199
200 decContextDefault (&set, DEC_INIT_DECIMAL128);
201 set.traps = 0;
202
203 decimal_to_decnumber (r, &dn);
204 decimal64FromNumber (&d64, &dn, &set);
205
206 if (WORDS_BIGENDIAN == FLOAT_WORDS_BIG_ENDIAN)
207 {
208 memcpy (&image, &d64.bytes[0], sizeof (int32_t));
209 buf[0] = image;
210 memcpy (&image, &d64.bytes[4], sizeof (int32_t));
211 buf[1] = image;
212 }
213 else
214 {
215 memcpy (&image, &d64.bytes[4], sizeof (int32_t));
216 buf[0] = image;
217 memcpy (&image, &d64.bytes[0], sizeof (int32_t));
218 buf[1] = image;
219 }
220 }
221
222 /* Decode an IEEE 754 decimal64 type into a real. */
223
224 void
decode_decimal64(const struct real_format * fmt ATTRIBUTE_UNUSED,REAL_VALUE_TYPE * r,const long * buf)225 decode_decimal64 (const struct real_format *fmt ATTRIBUTE_UNUSED,
226 REAL_VALUE_TYPE *r, const long *buf)
227 {
228 decNumber dn;
229 decimal64 d64;
230 decContext set;
231 int32_t image;
232
233 decContextDefault (&set, DEC_INIT_DECIMAL128);
234 set.traps = 0;
235
236 if (WORDS_BIGENDIAN == FLOAT_WORDS_BIG_ENDIAN)
237 {
238 image = buf[0];
239 memcpy (&d64.bytes[0], &image, sizeof (int32_t));
240 image = buf[1];
241 memcpy (&d64.bytes[4], &image, sizeof (int32_t));
242 }
243 else
244 {
245 image = buf[1];
246 memcpy (&d64.bytes[0], &image, sizeof (int32_t));
247 image = buf[0];
248 memcpy (&d64.bytes[4], &image, sizeof (int32_t));
249 }
250
251 decimal64ToNumber (&d64, &dn);
252 decimal_from_decnumber (r, &dn, &set);
253 }
254
255 /* Encode a real into an IEEE 754 decimal128 type. */
256
257 void
encode_decimal128(const struct real_format * fmt ATTRIBUTE_UNUSED,long * buf,const REAL_VALUE_TYPE * r)258 encode_decimal128 (const struct real_format *fmt ATTRIBUTE_UNUSED,
259 long *buf, const REAL_VALUE_TYPE *r)
260 {
261 decNumber dn;
262 decContext set;
263 decimal128 d128;
264 int32_t image;
265
266 decContextDefault (&set, DEC_INIT_DECIMAL128);
267 set.traps = 0;
268
269 decimal_to_decnumber (r, &dn);
270 decimal128FromNumber (&d128, &dn, &set);
271
272 if (WORDS_BIGENDIAN == FLOAT_WORDS_BIG_ENDIAN)
273 {
274 memcpy (&image, &d128.bytes[0], sizeof (int32_t));
275 buf[0] = image;
276 memcpy (&image, &d128.bytes[4], sizeof (int32_t));
277 buf[1] = image;
278 memcpy (&image, &d128.bytes[8], sizeof (int32_t));
279 buf[2] = image;
280 memcpy (&image, &d128.bytes[12], sizeof (int32_t));
281 buf[3] = image;
282 }
283 else
284 {
285 memcpy (&image, &d128.bytes[12], sizeof (int32_t));
286 buf[0] = image;
287 memcpy (&image, &d128.bytes[8], sizeof (int32_t));
288 buf[1] = image;
289 memcpy (&image, &d128.bytes[4], sizeof (int32_t));
290 buf[2] = image;
291 memcpy (&image, &d128.bytes[0], sizeof (int32_t));
292 buf[3] = image;
293 }
294 }
295
296 /* Decode an IEEE 754 decimal128 type into a real. */
297
298 void
decode_decimal128(const struct real_format * fmt ATTRIBUTE_UNUSED,REAL_VALUE_TYPE * r,const long * buf)299 decode_decimal128 (const struct real_format *fmt ATTRIBUTE_UNUSED,
300 REAL_VALUE_TYPE *r, const long *buf)
301 {
302 decNumber dn;
303 decimal128 d128;
304 decContext set;
305 int32_t image;
306
307 decContextDefault (&set, DEC_INIT_DECIMAL128);
308 set.traps = 0;
309
310 if (WORDS_BIGENDIAN == FLOAT_WORDS_BIG_ENDIAN)
311 {
312 image = buf[0];
313 memcpy (&d128.bytes[0], &image, sizeof (int32_t));
314 image = buf[1];
315 memcpy (&d128.bytes[4], &image, sizeof (int32_t));
316 image = buf[2];
317 memcpy (&d128.bytes[8], &image, sizeof (int32_t));
318 image = buf[3];
319 memcpy (&d128.bytes[12], &image, sizeof (int32_t));
320 }
321 else
322 {
323 image = buf[3];
324 memcpy (&d128.bytes[0], &image, sizeof (int32_t));
325 image = buf[2];
326 memcpy (&d128.bytes[4], &image, sizeof (int32_t));
327 image = buf[1];
328 memcpy (&d128.bytes[8], &image, sizeof (int32_t));
329 image = buf[0];
330 memcpy (&d128.bytes[12], &image, sizeof (int32_t));
331 }
332
333 decimal128ToNumber (&d128, &dn);
334 decimal_from_decnumber (r, &dn, &set);
335 }
336
337 /* Helper function to convert from a binary real internal
338 representation. */
339
340 static void
decimal_to_binary(REAL_VALUE_TYPE * to,const REAL_VALUE_TYPE * from,const real_format * fmt)341 decimal_to_binary (REAL_VALUE_TYPE *to, const REAL_VALUE_TYPE *from,
342 const real_format *fmt)
343 {
344 char string[256];
345 if (from->cl == rvc_normal)
346 {
347 const decimal128 *const d128 = (const decimal128 *) from->sig;
348 decimal128ToString (d128, string);
349 }
350 else
351 real_to_decimal (string, from, sizeof (string), 0, 1);
352 real_from_string3 (to, string, fmt);
353 }
354
355
356 /* Helper function to convert from a binary real internal
357 representation. */
358
359 static void
decimal_from_binary(REAL_VALUE_TYPE * to,const REAL_VALUE_TYPE * from)360 decimal_from_binary (REAL_VALUE_TYPE *to, const REAL_VALUE_TYPE *from)
361 {
362 char string[256];
363
364 /* We convert to string, then to decNumber then to decimal128. */
365 real_to_decimal (string, from, sizeof (string), 0, 1);
366 decimal_real_from_string (to, string);
367 }
368
369 /* Helper function to real.c:do_compare() to handle decimal internal
370 representation including when one of the operands is still in the
371 binary internal representation. */
372
373 int
decimal_do_compare(const REAL_VALUE_TYPE * a,const REAL_VALUE_TYPE * b,int nan_result)374 decimal_do_compare (const REAL_VALUE_TYPE *a, const REAL_VALUE_TYPE *b,
375 int nan_result)
376 {
377 decContext set;
378 decNumber dn, dn2, dn3;
379 REAL_VALUE_TYPE a1, b1;
380
381 /* If either operand is non-decimal, create temporary versions. */
382 if (!a->decimal)
383 {
384 decimal_from_binary (&a1, a);
385 a = &a1;
386 }
387 if (!b->decimal)
388 {
389 decimal_from_binary (&b1, b);
390 b = &b1;
391 }
392
393 /* Convert into decNumber form for comparison operation. */
394 decContextDefault (&set, DEC_INIT_DECIMAL128);
395 set.traps = 0;
396 decimal128ToNumber ((const decimal128 *) a->sig, &dn2);
397 decimal128ToNumber ((const decimal128 *) b->sig, &dn3);
398
399 /* Finally, do the comparison. */
400 decNumberCompare (&dn, &dn2, &dn3, &set);
401
402 /* Return the comparison result. */
403 if (decNumberIsNaN (&dn))
404 return nan_result;
405 else if (decNumberIsZero (&dn))
406 return 0;
407 else if (decNumberIsNegative (&dn))
408 return -1;
409 else
410 return 1;
411 }
412
413 /* Helper to round_for_format, handling decimal float types. */
414
415 void
decimal_round_for_format(const struct real_format * fmt,REAL_VALUE_TYPE * r)416 decimal_round_for_format (const struct real_format *fmt, REAL_VALUE_TYPE *r)
417 {
418 decNumber dn;
419 decContext set;
420
421 /* Real encoding occurs later. */
422 if (r->cl != rvc_normal)
423 return;
424
425 decContextDefault (&set, DEC_INIT_DECIMAL128);
426 set.traps = 0;
427 decimal128ToNumber ((decimal128 *) r->sig, &dn);
428
429 if (fmt == &decimal_quad_format)
430 {
431 /* The internal format is already in this format. */
432 return;
433 }
434 else if (fmt == &decimal_single_format)
435 {
436 decimal32 d32;
437 decContextDefault (&set, DEC_INIT_DECIMAL32);
438 set.traps = 0;
439
440 decimal32FromNumber (&d32, &dn, &set);
441 decimal32ToNumber (&d32, &dn);
442 }
443 else if (fmt == &decimal_double_format)
444 {
445 decimal64 d64;
446 decContextDefault (&set, DEC_INIT_DECIMAL64);
447 set.traps = 0;
448
449 decimal64FromNumber (&d64, &dn, &set);
450 decimal64ToNumber (&d64, &dn);
451 }
452 else
453 gcc_unreachable ();
454
455 decimal_from_decnumber (r, &dn, &set);
456 }
457
458 /* Extend or truncate to a new mode. Handles conversions between
459 binary and decimal types. */
460
461 void
decimal_real_convert(REAL_VALUE_TYPE * r,const real_format * fmt,const REAL_VALUE_TYPE * a)462 decimal_real_convert (REAL_VALUE_TYPE *r, const real_format *fmt,
463 const REAL_VALUE_TYPE *a)
464 {
465 if (a->decimal && fmt->b == 10)
466 return;
467 if (a->decimal)
468 decimal_to_binary (r, a, fmt);
469 else
470 decimal_from_binary (r, a);
471 }
472
473 /* Render R_ORIG as a decimal floating point constant. Emit DIGITS
474 significant digits in the result, bounded by BUF_SIZE. If DIGITS
475 is 0, choose the maximum for the representation. If
476 CROP_TRAILING_ZEROS, strip trailing zeros. Currently, not honoring
477 DIGITS or CROP_TRAILING_ZEROS. */
478
479 void
decimal_real_to_decimal(char * str,const REAL_VALUE_TYPE * r_orig,size_t buf_size,size_t digits ATTRIBUTE_UNUSED,int crop_trailing_zeros ATTRIBUTE_UNUSED)480 decimal_real_to_decimal (char *str, const REAL_VALUE_TYPE *r_orig,
481 size_t buf_size,
482 size_t digits ATTRIBUTE_UNUSED,
483 int crop_trailing_zeros ATTRIBUTE_UNUSED)
484 {
485 const decimal128 *const d128 = (const decimal128*) r_orig->sig;
486
487 /* decimal128ToString requires space for at least 24 characters;
488 Require two more for suffix. */
489 gcc_assert (buf_size >= 24);
490 decimal128ToString (d128, str);
491 }
492
493 static bool
decimal_do_add(REAL_VALUE_TYPE * r,const REAL_VALUE_TYPE * op0,const REAL_VALUE_TYPE * op1,int subtract_p)494 decimal_do_add (REAL_VALUE_TYPE *r, const REAL_VALUE_TYPE *op0,
495 const REAL_VALUE_TYPE *op1, int subtract_p)
496 {
497 decNumber dn;
498 decContext set;
499 decNumber dn2, dn3;
500
501 decimal_to_decnumber (op0, &dn2);
502 decimal_to_decnumber (op1, &dn3);
503
504 decContextDefault (&set, DEC_INIT_DECIMAL128);
505 set.traps = 0;
506
507 if (subtract_p)
508 decNumberSubtract (&dn, &dn2, &dn3, &set);
509 else
510 decNumberAdd (&dn, &dn2, &dn3, &set);
511
512 decimal_from_decnumber (r, &dn, &set);
513
514 /* Return true, if inexact. */
515 return (set.status & DEC_Inexact);
516 }
517
518 /* Compute R = OP0 * OP1. */
519
520 static bool
decimal_do_multiply(REAL_VALUE_TYPE * r,const REAL_VALUE_TYPE * op0,const REAL_VALUE_TYPE * op1)521 decimal_do_multiply (REAL_VALUE_TYPE *r, const REAL_VALUE_TYPE *op0,
522 const REAL_VALUE_TYPE *op1)
523 {
524 decContext set;
525 decNumber dn, dn2, dn3;
526
527 decimal_to_decnumber (op0, &dn2);
528 decimal_to_decnumber (op1, &dn3);
529
530 decContextDefault (&set, DEC_INIT_DECIMAL128);
531 set.traps = 0;
532
533 decNumberMultiply (&dn, &dn2, &dn3, &set);
534 decimal_from_decnumber (r, &dn, &set);
535
536 /* Return true, if inexact. */
537 return (set.status & DEC_Inexact);
538 }
539
540 /* Compute R = OP0 / OP1. */
541
542 static bool
decimal_do_divide(REAL_VALUE_TYPE * r,const REAL_VALUE_TYPE * op0,const REAL_VALUE_TYPE * op1)543 decimal_do_divide (REAL_VALUE_TYPE *r, const REAL_VALUE_TYPE *op0,
544 const REAL_VALUE_TYPE *op1)
545 {
546 decContext set;
547 decNumber dn, dn2, dn3;
548
549 decimal_to_decnumber (op0, &dn2);
550 decimal_to_decnumber (op1, &dn3);
551
552 decContextDefault (&set, DEC_INIT_DECIMAL128);
553 set.traps = 0;
554
555 decNumberDivide (&dn, &dn2, &dn3, &set);
556 decimal_from_decnumber (r, &dn, &set);
557
558 /* Return true, if inexact. */
559 return (set.status & DEC_Inexact);
560 }
561
562 /* Set R to A truncated to an integral value toward zero (decimal
563 floating point). */
564
565 void
decimal_do_fix_trunc(REAL_VALUE_TYPE * r,const REAL_VALUE_TYPE * a)566 decimal_do_fix_trunc (REAL_VALUE_TYPE *r, const REAL_VALUE_TYPE *a)
567 {
568 decNumber dn, dn2;
569 decContext set;
570
571 decContextDefault (&set, DEC_INIT_DECIMAL128);
572 set.traps = 0;
573 set.round = DEC_ROUND_DOWN;
574 decimal128ToNumber ((const decimal128 *) a->sig, &dn2);
575
576 decNumberToIntegralValue (&dn, &dn2, &set);
577 decimal_from_decnumber (r, &dn, &set);
578 }
579
580 /* Render decimal float value R as an integer. */
581
582 HOST_WIDE_INT
decimal_real_to_integer(const REAL_VALUE_TYPE * r)583 decimal_real_to_integer (const REAL_VALUE_TYPE *r)
584 {
585 decContext set;
586 decNumber dn, dn2, dn3;
587 REAL_VALUE_TYPE to;
588 char string[256];
589
590 decContextDefault (&set, DEC_INIT_DECIMAL128);
591 set.traps = 0;
592 set.round = DEC_ROUND_DOWN;
593 decimal128ToNumber ((const decimal128 *) r->sig, &dn);
594
595 decNumberToIntegralValue (&dn2, &dn, &set);
596 decNumberZero (&dn3);
597 decNumberRescale (&dn, &dn2, &dn3, &set);
598
599 /* Convert to REAL_VALUE_TYPE and call appropriate conversion
600 function. */
601 decNumberToString (&dn, string);
602 real_from_string (&to, string);
603 return real_to_integer (&to);
604 }
605
606 /* Likewise, but returns a wide_int with PRECISION. *FAIL is set if the
607 value does not fit. */
608
609 wide_int
decimal_real_to_integer(const REAL_VALUE_TYPE * r,bool * fail,int precision)610 decimal_real_to_integer (const REAL_VALUE_TYPE *r, bool *fail, int precision)
611 {
612 decContext set;
613 decNumber dn, dn2, dn3;
614 REAL_VALUE_TYPE to;
615 char string[256];
616
617 decContextDefault (&set, DEC_INIT_DECIMAL128);
618 set.traps = 0;
619 set.round = DEC_ROUND_DOWN;
620 decimal128ToNumber ((const decimal128 *) r->sig, &dn);
621
622 decNumberToIntegralValue (&dn2, &dn, &set);
623 decNumberZero (&dn3);
624 decNumberRescale (&dn, &dn2, &dn3, &set);
625
626 /* Convert to REAL_VALUE_TYPE and call appropriate conversion
627 function. */
628 decNumberToString (&dn, string);
629 real_from_string (&to, string);
630 return real_to_integer (&to, fail, precision);
631 }
632
633 /* Perform the decimal floating point operation described by CODE.
634 For a unary operation, OP1 will be NULL. This function returns
635 true if the result may be inexact due to loss of precision. */
636
637 bool
decimal_real_arithmetic(REAL_VALUE_TYPE * r,enum tree_code code,const REAL_VALUE_TYPE * op0,const REAL_VALUE_TYPE * op1)638 decimal_real_arithmetic (REAL_VALUE_TYPE *r, enum tree_code code,
639 const REAL_VALUE_TYPE *op0,
640 const REAL_VALUE_TYPE *op1)
641 {
642 REAL_VALUE_TYPE a, b;
643
644 /* If either operand is non-decimal, create temporaries. */
645 if (!op0->decimal)
646 {
647 decimal_from_binary (&a, op0);
648 op0 = &a;
649 }
650 if (op1 && !op1->decimal)
651 {
652 decimal_from_binary (&b, op1);
653 op1 = &b;
654 }
655
656 switch (code)
657 {
658 case PLUS_EXPR:
659 return decimal_do_add (r, op0, op1, 0);
660
661 case MINUS_EXPR:
662 return decimal_do_add (r, op0, op1, 1);
663
664 case MULT_EXPR:
665 return decimal_do_multiply (r, op0, op1);
666
667 case RDIV_EXPR:
668 return decimal_do_divide (r, op0, op1);
669
670 case MIN_EXPR:
671 if (op1->cl == rvc_nan)
672 *r = *op1;
673 else if (real_compare (UNLT_EXPR, op0, op1))
674 *r = *op0;
675 else
676 *r = *op1;
677 return false;
678
679 case MAX_EXPR:
680 if (op1->cl == rvc_nan)
681 *r = *op1;
682 else if (real_compare (LT_EXPR, op0, op1))
683 *r = *op1;
684 else
685 *r = *op0;
686 return false;
687
688 case NEGATE_EXPR:
689 {
690 *r = *op0;
691 /* Flip sign bit. */
692 decimal128FlipSign ((decimal128 *) r->sig);
693 /* Keep sign field in sync. */
694 r->sign ^= 1;
695 }
696 return false;
697
698 case ABS_EXPR:
699 {
700 *r = *op0;
701 /* Clear sign bit. */
702 decimal128ClearSign ((decimal128 *) r->sig);
703 /* Keep sign field in sync. */
704 r->sign = 0;
705 }
706 return false;
707
708 case FIX_TRUNC_EXPR:
709 decimal_do_fix_trunc (r, op0);
710 return false;
711
712 default:
713 gcc_unreachable ();
714 }
715 }
716
717 /* Fills R with the largest finite value representable in mode MODE.
718 If SIGN is nonzero, R is set to the most negative finite value. */
719
720 void
decimal_real_maxval(REAL_VALUE_TYPE * r,int sign,machine_mode mode)721 decimal_real_maxval (REAL_VALUE_TYPE *r, int sign, machine_mode mode)
722 {
723 const char *max;
724
725 switch (mode)
726 {
727 case E_SDmode:
728 max = "9.999999E96";
729 break;
730 case E_DDmode:
731 max = "9.999999999999999E384";
732 break;
733 case E_TDmode:
734 max = "9.999999999999999999999999999999999E6144";
735 break;
736 default:
737 gcc_unreachable ();
738 }
739
740 decimal_real_from_string (r, max);
741 if (sign)
742 decimal128SetSign ((decimal128 *) r->sig, 1);
743
744 r->sign = sign;
745 }
746