Coverage Report

Created: 2023-06-29 07:09

/src/binutils-gdb/gas/config/atof-ieee.c
Line
Count
Source (jump to first uncovered line)
1
/* atof_ieee.c - turn a Flonum into an IEEE floating point number
2
   Copyright (C) 1987-2023 Free Software Foundation, Inc.
3
4
   This file is part of GAS, the GNU Assembler.
5
6
   GAS is free software; you can redistribute it and/or modify
7
   it under the terms of the GNU General Public License as published by
8
   the Free Software Foundation; either version 3, or (at your option)
9
   any later version.
10
11
   GAS is distributed in the hope that it will be useful,
12
   but WITHOUT ANY WARRANTY; without even the implied warranty of
13
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14
   GNU General Public License for more details.
15
16
   You should have received a copy of the GNU General Public License
17
   along with GAS; see the file COPYING.  If not, write to the Free
18
   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
19
   02110-1301, USA.  */
20
21
#include "as.h"
22
#include "safe-ctype.h"
23
24
/* Flonums returned here.  */
25
extern FLONUM_TYPE generic_floating_point_number;
26
27
/* Precision in LittleNums.  */
28
/* Don't count the gap in the m68k extended precision format.  */
29
70.7k
#define MAX_PRECISION  5
30
8
#define H_PRECISION    1
31
24
#define B_PRECISION    1 /* Not strictly IEEE, but handled here anyway.  */
32
69.4k
#define F_PRECISION    2
33
2
#define D_PRECISION    4
34
2.08k
#define X_PRECISION    5
35
#ifndef X_PRECISION_PAD
36
#define X_PRECISION_PAD 0
37
#endif
38
607
#define P_PRECISION    5
39
#ifndef P_PRECISION_PAD
40
607
#define P_PRECISION_PAD X_PRECISION_PAD
41
#endif
42
43
/* Length in LittleNums of guard bits.  */
44
35.3k
#define GUARD          2
45
46
#ifndef TC_LARGEST_EXPONENT_IS_NORMAL
47
50.7k
#define TC_LARGEST_EXPONENT_IS_NORMAL(PRECISION) 0
48
#endif
49
50
static const unsigned long mask[] =
51
{
52
  0x00000000,
53
  0x00000001,
54
  0x00000003,
55
  0x00000007,
56
  0x0000000f,
57
  0x0000001f,
58
  0x0000003f,
59
  0x0000007f,
60
  0x000000ff,
61
  0x000001ff,
62
  0x000003ff,
63
  0x000007ff,
64
  0x00000fff,
65
  0x00001fff,
66
  0x00003fff,
67
  0x00007fff,
68
  0x0000ffff,
69
  0x0001ffff,
70
  0x0003ffff,
71
  0x0007ffff,
72
  0x000fffff,
73
  0x001fffff,
74
  0x003fffff,
75
  0x007fffff,
76
  0x00ffffff,
77
  0x01ffffff,
78
  0x03ffffff,
79
  0x07ffffff,
80
  0x0fffffff,
81
  0x1fffffff,
82
  0x3fffffff,
83
  0x7fffffff,
84
  0xffffffff,
85
};
86

87
static int bits_left_in_littlenum;
88
static int littlenums_left;
89
static LITTLENUM_TYPE *littlenum_pointer;
90
91
static int
92
next_bits (int number_of_bits)
93
381k
{
94
381k
  int return_value;
95
96
381k
  if (!littlenums_left)
97
51.9k
    return 0;
98
99
329k
  if (number_of_bits >= bits_left_in_littlenum)
100
26.7k
    {
101
26.7k
      return_value = mask[bits_left_in_littlenum] & *littlenum_pointer;
102
26.7k
      number_of_bits -= bits_left_in_littlenum;
103
26.7k
      return_value <<= number_of_bits;
104
105
26.7k
      if (--littlenums_left)
106
2.21k
  {
107
2.21k
    bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits;
108
2.21k
    --littlenum_pointer;
109
2.21k
    return_value |=
110
2.21k
      (*littlenum_pointer >> bits_left_in_littlenum)
111
2.21k
      & mask[number_of_bits];
112
2.21k
  }
113
26.7k
    }
114
303k
  else
115
303k
    {
116
303k
      bits_left_in_littlenum -= number_of_bits;
117
303k
      return_value =
118
303k
  mask[number_of_bits] & (*littlenum_pointer >> bits_left_in_littlenum);
119
303k
    }
120
329k
  return return_value;
121
381k
}
122
123
/* Num had better be less than LITTLENUM_NUMBER_OF_BITS.  */
124
125
static void
126
unget_bits (int num)
127
21
{
128
21
  if (!littlenums_left)
129
0
    {
130
0
      ++littlenum_pointer;
131
0
      ++littlenums_left;
132
0
      bits_left_in_littlenum = num;
133
0
    }
134
21
  else if (bits_left_in_littlenum + num > LITTLENUM_NUMBER_OF_BITS)
135
0
    {
136
0
      bits_left_in_littlenum =
137
0
  num - (LITTLENUM_NUMBER_OF_BITS - bits_left_in_littlenum);
138
0
      ++littlenum_pointer;
139
0
      ++littlenums_left;
140
0
    }
141
21
  else
142
21
    bits_left_in_littlenum += num;
143
21
}
144
145
static void
146
make_invalid_floating_point_number (LITTLENUM_TYPE *words)
147
59
{
148
59
  as_bad (_("cannot create floating-point number"));
149
  /* Zero the leftmost bit.  */
150
59
  words[0] = (LITTLENUM_TYPE) ((unsigned) -1) >> 1;
151
59
  words[1] = (LITTLENUM_TYPE) -1;
152
59
  words[2] = (LITTLENUM_TYPE) -1;
153
59
  words[3] = (LITTLENUM_TYPE) -1;
154
59
  words[4] = (LITTLENUM_TYPE) -1;
155
59
  words[5] = (LITTLENUM_TYPE) -1;
156
59
}
157
158
/* Build a floating point constant at str into a IEEE floating
159
   point number.  This function does the same thing as atof_ieee
160
   however it allows more control over the exact format, i.e.
161
   explicitly specifying the precision and number of exponent bits
162
   instead of relying on this infomation being deduced from a given type.
163
164
   If generic_float_info is not NULL then it will be set to contain generic
165
   infomation about the parsed floating point number.
166
167
   Returns pointer past text consumed. */
168
char *
169
atof_ieee_detail (char * str,
170
      int precision,
171
      int exponent_bits,
172
      LITTLENUM_TYPE * words,
173
      FLONUM_TYPE * generic_float_info)
174
35.3k
{
175
  /* Extra bits for zeroed low-order bits.
176
     The 1st MAX_PRECISION are zeroed, the last contain flonum bits.  */
177
35.3k
  static LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD];
178
35.3k
  char *return_value;
179
180
  /* Number of 16-bit words in the format.  */
181
35.3k
  FLONUM_TYPE save_gen_flonum;
182
183
  /* We have to save the generic_floating_point_number because it
184
     contains storage allocation about the array of LITTLENUMs where
185
     the value is actually stored.  We will allocate our own array of
186
     littlenums below, but have to restore the global one on exit.  */
187
35.3k
  save_gen_flonum = generic_floating_point_number;
188
189
35.3k
  return_value = str;
190
35.3k
  generic_floating_point_number.low = bits + MAX_PRECISION;
191
35.3k
  generic_floating_point_number.high = NULL;
192
35.3k
  generic_floating_point_number.leader = NULL;
193
35.3k
  generic_floating_point_number.exponent = 0;
194
35.3k
  generic_floating_point_number.sign = '\0';
195
196
  /* Use more LittleNums than seems necessary: the highest flonum may
197
     have 15 leading 0 bits, so could be useless.  */
198
199
35.3k
  memset (bits, '\0', sizeof (LITTLENUM_TYPE) * MAX_PRECISION);
200
201
35.3k
  generic_floating_point_number.high
202
35.3k
    = generic_floating_point_number.low + precision - 1 + GUARD;
203
204
35.3k
  if (atof_generic (&return_value, ".", EXP_CHARS,
205
35.3k
        &generic_floating_point_number))
206
0
    {
207
0
      make_invalid_floating_point_number (words);
208
0
      return NULL;
209
0
    }
210
211
35.3k
  if (generic_float_info)
212
0
    *generic_float_info = generic_floating_point_number;
213
214
35.3k
  gen_to_words (words, precision, exponent_bits);
215
216
  /* Restore the generic_floating_point_number's storage alloc (and
217
     everything else).  */
218
35.3k
  generic_floating_point_number = save_gen_flonum;
219
220
35.3k
  return return_value;
221
35.3k
}
222
223
/* Warning: This returns 16-bit LITTLENUMs.  It is up to the caller to
224
   figure out any alignment problems and to conspire for the
225
   bytes/word to be emitted in the right order.  Bigendians beware!  */
226
227
/* Note that atof-ieee always has X and P precisions enabled.  it is up
228
   to md_atof to filter them out if the target machine does not support
229
   them.  */
230
231
/* Returns pointer past text consumed.  */
232
char *
233
atof_ieee (char *str,     /* Text to convert to binary.  */
234
     int what_kind,   /* 'd', 'f', 'x', 'p'.  */
235
     LITTLENUM_TYPE *words) /* Build the binary here.  */
236
35.3k
{
237
35.3k
  int precision;
238
35.3k
  long exponent_bits;
239
240
35.3k
  switch (what_kind)
241
35.3k
    {
242
2
    case 'h':
243
2
    case 'H':
244
2
      precision = H_PRECISION;
245
2
      exponent_bits = 5;
246
2
      break;
247
248
12
    case 'b':
249
12
    case 'B':
250
12
      precision = B_PRECISION;
251
12
      exponent_bits = 8;
252
12
      break;
253
254
34.7k
    case 'f':
255
34.7k
    case 'F':
256
34.7k
    case 's':
257
34.7k
    case 'S':
258
34.7k
      precision = F_PRECISION;
259
34.7k
      exponent_bits = 8;
260
34.7k
      break;
261
262
1
    case 'd':
263
1
    case 'D':
264
1
    case 'r':
265
1
    case 'R':
266
1
      precision = D_PRECISION;
267
1
      exponent_bits = 11;
268
1
      break;
269
270
607
    case 'x':
271
607
    case 'X':
272
607
    case 'e':
273
607
    case 'E':
274
607
      precision = X_PRECISION;
275
607
      exponent_bits = 15;
276
607
      break;
277
278
0
    case 'p':
279
0
    case 'P':
280
0
      precision = P_PRECISION;
281
0
      exponent_bits = -1;
282
0
      break;
283
284
0
    default:
285
0
      make_invalid_floating_point_number (words);
286
0
      return (NULL);
287
35.3k
    }
288
289
35.3k
  return atof_ieee_detail (str, precision, exponent_bits, words, NULL);
290
35.3k
}
291
292
/* Turn generic_floating_point_number into a real float/double/extended.  */
293
294
int
295
gen_to_words (LITTLENUM_TYPE *words, int precision, long exponent_bits)
296
35.3k
{
297
35.3k
  int return_value = 0;
298
299
35.3k
  long exponent_1;
300
35.3k
  long exponent_2;
301
35.3k
  long exponent_3;
302
35.3k
  long exponent_4;
303
35.3k
  int exponent_skippage;
304
35.3k
  LITTLENUM_TYPE word1;
305
35.3k
  LITTLENUM_TYPE *lp;
306
35.3k
  LITTLENUM_TYPE *words_end;
307
308
35.3k
  words_end = words + precision;
309
#ifdef TC_M68K
310
  if (precision == X_PRECISION)
311
    /* On the m68k the extended precision format has a gap of 16 bits
312
       between the exponent and the mantissa.  */
313
    words_end++;
314
#endif
315
316
35.3k
  if (generic_floating_point_number.low > generic_floating_point_number.leader)
317
9.90k
    {
318
      /* 0.0e0 seen.  */
319
9.90k
      if (generic_floating_point_number.sign == '+')
320
9.90k
  words[0] = 0x0000;
321
0
      else
322
0
  words[0] = 0x8000;
323
9.90k
      memset (&words[1], '\0',
324
9.90k
        (words_end - words - 1) * sizeof (LITTLENUM_TYPE));
325
9.90k
      return return_value;
326
9.90k
    }
327
328
25.4k
  switch (generic_floating_point_number.sign)
329
25.4k
    {
330
    /* NaN:  Do the right thing.  */
331
0
    case 0:
332
0
    case 'Q': case 'q':
333
0
    case 'S': case 's':
334
0
      if (TC_LARGEST_EXPONENT_IS_NORMAL (precision))
335
0
  as_warn (_("NaNs are not supported by this target"));
336
337
0
      if (precision == H_PRECISION)
338
0
  {
339
0
    if (TOUPPER (generic_floating_point_number.sign) != 'S')
340
0
      words[0] = 0x7fff;
341
0
    else
342
0
      words[0] = exponent_bits == 5 ? 0x7dff : 0x7fbf;
343
0
  }
344
0
      else if (precision == F_PRECISION)
345
0
  {
346
0
    words[0] = TOUPPER (generic_floating_point_number.sign) == 'S'
347
0
               ? 0x7fbf : 0x7fff;
348
0
    words[1] = 0xffff;
349
0
  }
350
0
      else if (precision == X_PRECISION)
351
0
  {
352
#ifdef TC_M68K
353
    if (generic_floating_point_number.sign)
354
      as_warn (_("NaN flavors are not supported by this target"));
355
356
    words[0] = 0x7fff;
357
    words[1] = 0;
358
    words[2] = 0xffff;
359
    words[3] = 0xffff;
360
    words[4] = 0xffff;
361
    words[5] = 0xffff;
362
#else /* ! TC_M68K  */
363
0
#ifdef TC_I386
364
0
    words[0] = 0x7fff;
365
0
    words[1] = TOUPPER (generic_floating_point_number.sign) == 'S'
366
0
         ? 0xbfff : 0xffff;
367
0
    words[2] = 0xffff;
368
0
    words[3] = 0xffff;
369
0
    words[4] = 0xffff;
370
#else /* ! TC_I386  */
371
    abort ();
372
#endif /* ! TC_I386  */
373
0
#endif /* ! TC_M68K  */
374
0
  }
375
0
      else
376
0
  {
377
0
    words[0] = TOUPPER (generic_floating_point_number.sign) == 'S'
378
0
               ? 0x7ff7 : 0x7fff;
379
0
    words[1] = 0xffff;
380
0
    words[2] = 0xffff;
381
0
    words[3] = 0xffff;
382
0
  }
383
384
0
      if (ISLOWER (generic_floating_point_number.sign))
385
0
  words[0] |= 0x8000;
386
387
0
      return return_value;
388
389
0
    case 'P':
390
4
    case 'N':
391
4
      if (TC_LARGEST_EXPONENT_IS_NORMAL (precision))
392
0
  as_warn (_("Infinities are not supported by this target"));
393
394
      /* +INF:  Do the right thing.  */
395
4
      if (precision == H_PRECISION /* also B_PRECISION */)
396
0
  {
397
0
    words[0] = exponent_bits == 5 ? 0x7c00 : 0x7f80;
398
0
  }
399
4
      else if (precision == F_PRECISION)
400
4
  {
401
4
    words[0] = 0x7f80;
402
4
    words[1] = 0;
403
4
  }
404
0
      else if (precision == X_PRECISION)
405
0
  {
406
#ifdef TC_M68K
407
    words[0] = 0x7fff;
408
    words[1] = 0;
409
    words[2] = 0;
410
    words[3] = 0;
411
    words[4] = 0;
412
    words[5] = 0;
413
#else /* ! TC_M68K  */
414
0
#ifdef TC_I386
415
0
    words[0] = 0x7fff;
416
0
    words[1] = 0x8000;
417
0
    words[2] = 0;
418
0
    words[3] = 0;
419
0
    words[4] = 0;
420
#else /* ! TC_I386  */
421
    abort ();
422
#endif /* ! TC_I386  */
423
0
#endif /* ! TC_M68K  */
424
0
  }
425
0
      else
426
0
  {
427
0
    words[0] = 0x7ff0;
428
0
    words[1] = 0;
429
0
    words[2] = 0;
430
0
    words[3] = 0;
431
0
  }
432
433
4
      if (generic_floating_point_number.sign == 'N')
434
4
  words[0] |= 0x8000;
435
436
4
      return return_value;
437
25.4k
    }
438
439
  /* The floating point formats we support have:
440
     Bit 15 is sign bit.
441
     Bits 14:n are excess-whatever exponent.
442
     Bits n-1:0 (if any) are most significant bits of fraction.
443
     Bits 15:0 of the next word(s) are the next most significant bits.
444
445
     So we need: number of bits of exponent, number of bits of
446
     mantissa.  */
447
25.4k
  bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
448
25.4k
  littlenum_pointer = generic_floating_point_number.leader;
449
25.4k
  littlenums_left = (1
450
25.4k
         + generic_floating_point_number.leader
451
25.4k
         - generic_floating_point_number.low);
452
453
  /* Seek (and forget) 1st significant bit.  */
454
303k
  for (exponent_skippage = 0; !next_bits (1); ++exponent_skippage);
455
25.4k
  exponent_1 = (generic_floating_point_number.exponent
456
25.4k
    + generic_floating_point_number.leader
457
25.4k
    + 1
458
25.4k
    - generic_floating_point_number.low);
459
460
  /* Radix LITTLENUM_RADIX, point just higher than
461
     generic_floating_point_number.leader.  */
462
25.4k
  exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS;
463
464
  /* Radix 2.  */
465
25.4k
  exponent_3 = exponent_2 - exponent_skippage;
466
467
  /* Forget leading zeros, forget 1st bit.  */
468
25.4k
  exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2);
469
470
  /* Offset exponent.  */
471
25.4k
  lp = words;
472
473
  /* Word 1.  Sign, exponent and perhaps high bits.  */
474
25.4k
  word1 = ((generic_floating_point_number.sign == '+')
475
25.4k
     ? 0
476
25.4k
     : (1 << (LITTLENUM_NUMBER_OF_BITS - 1)));
477
478
  /* Assume 2's complement integers.  */
479
25.4k
  if (exponent_4 <= 0)
480
21
    {
481
21
      int prec_bits;
482
21
      int num_bits;
483
484
21
      unget_bits (1);
485
21
      num_bits = -exponent_4;
486
21
      prec_bits =
487
21
  LITTLENUM_NUMBER_OF_BITS * precision - (exponent_bits + 1 + num_bits);
488
21
#ifdef TC_I386
489
21
      if (precision == X_PRECISION && exponent_bits == 15)
490
0
  {
491
    /* On the i386 a denormalized extended precision float is
492
       shifted down by one, effectively decreasing the exponent
493
       bias by one.  */
494
0
    prec_bits -= 1;
495
0
    num_bits += 1;
496
0
  }
497
21
#endif
498
499
21
      if (num_bits >= LITTLENUM_NUMBER_OF_BITS - exponent_bits)
500
0
  {
501
    /* Bigger than one littlenum.  */
502
0
    num_bits -= (LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits;
503
0
    *lp++ = word1;
504
0
    if (num_bits + exponent_bits + 1
505
0
        > precision * LITTLENUM_NUMBER_OF_BITS)
506
0
      {
507
        /* Exponent overflow.  */
508
0
        make_invalid_floating_point_number (words);
509
0
        return return_value;
510
0
      }
511
#ifdef TC_M68K
512
    if (precision == X_PRECISION && exponent_bits == 15)
513
      *lp++ = 0;
514
#endif
515
0
    while (num_bits >= LITTLENUM_NUMBER_OF_BITS)
516
0
      {
517
0
        num_bits -= LITTLENUM_NUMBER_OF_BITS;
518
0
        *lp++ = 0;
519
0
      }
520
0
    if (num_bits)
521
0
      *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - (num_bits));
522
0
  }
523
21
      else
524
21
  {
525
21
    if (precision == X_PRECISION && exponent_bits == 15)
526
0
      {
527
0
        *lp++ = word1;
528
#ifdef TC_M68K
529
        *lp++ = 0;
530
#endif
531
0
        *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS - num_bits);
532
0
      }
533
21
    else
534
21
      {
535
21
        word1 |= next_bits ((LITTLENUM_NUMBER_OF_BITS - 1)
536
21
          - (exponent_bits + num_bits));
537
21
        *lp++ = word1;
538
21
      }
539
21
  }
540
42
      while (lp < words_end)
541
21
  *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS);
542
543
      /* Round the mantissa up, but don't change the number.  */
544
21
      if (next_bits (1))
545
21
  {
546
21
    --lp;
547
21
    if (prec_bits >= LITTLENUM_NUMBER_OF_BITS)
548
21
      {
549
21
        int n = 0;
550
21
        int tmp_bits;
551
552
21
        n = 0;
553
21
        tmp_bits = prec_bits;
554
21
        while (tmp_bits > LITTLENUM_NUMBER_OF_BITS)
555
21
    {
556
21
      if (lp[n] != (LITTLENUM_TYPE) - 1)
557
21
        break;
558
0
      --n;
559
0
      tmp_bits -= LITTLENUM_NUMBER_OF_BITS;
560
0
    }
561
21
        if (tmp_bits > LITTLENUM_NUMBER_OF_BITS
562
21
      || (lp[n] & mask[tmp_bits]) != mask[tmp_bits]
563
21
      || (prec_bits != (precision * LITTLENUM_NUMBER_OF_BITS
564
0
            - exponent_bits - 1)
565
0
#ifdef TC_I386
566
          /* An extended precision float with only the integer
567
       bit set would be invalid.  That must be converted
568
       to the smallest normalized number.  */
569
0
          && !(precision == X_PRECISION
570
0
         && prec_bits == (precision * LITTLENUM_NUMBER_OF_BITS
571
0
              - exponent_bits - 2))
572
0
#endif
573
0
          ))
574
21
    {
575
21
      unsigned long carry;
576
577
42
      for (carry = 1; carry && (lp >= words); lp--)
578
21
        {
579
21
          carry = *lp + carry;
580
21
          *lp = carry;
581
21
          carry >>= LITTLENUM_NUMBER_OF_BITS;
582
21
        }
583
21
    }
584
0
        else
585
0
    {
586
      /* This is an overflow of the denormal numbers.  We
587
                     need to forget what we have produced, and instead
588
                     generate the smallest normalized number.  */
589
0
      lp = words;
590
0
      word1 = ((generic_floating_point_number.sign == '+')
591
0
         ? 0
592
0
         : (1 << (LITTLENUM_NUMBER_OF_BITS - 1)));
593
0
      word1 |= (1
594
0
          << ((LITTLENUM_NUMBER_OF_BITS - 1)
595
0
        - exponent_bits));
596
0
      *lp++ = word1;
597
0
#ifdef TC_I386
598
      /* Set the integer bit in the extended precision format.
599
         This cannot happen on the m68k where the mantissa
600
         just overflows into the integer bit above.  */
601
0
      if (precision == X_PRECISION)
602
0
        *lp++ = 1 << (LITTLENUM_NUMBER_OF_BITS - 1);
603
0
#endif
604
0
      while (lp < words_end)
605
0
        *lp++ = 0;
606
0
    }
607
21
      }
608
0
    else
609
0
      *lp += 1;
610
21
  }
611
612
21
      return return_value;
613
21
    }
614
25.4k
  else if ((unsigned long) exponent_4 > mask[exponent_bits]
615
25.4k
     || (! TC_LARGEST_EXPONENT_IS_NORMAL (precision)
616
25.3k
         && (unsigned long) exponent_4 == mask[exponent_bits]))
617
59
    {
618
      /* Exponent overflow.  Lose immediately.  */
619
620
      /* We leave return_value alone: admit we read the
621
   number, but return a floating exception
622
   because we can't encode the number.  */
623
59
      make_invalid_floating_point_number (words);
624
59
      return return_value;
625
59
    }
626
25.3k
  else
627
25.3k
    {
628
25.3k
      word1 |= (exponent_4 << ((LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits))
629
25.3k
  | next_bits ((LITTLENUM_NUMBER_OF_BITS - 1) - exponent_bits);
630
25.3k
    }
631
632
25.3k
  *lp++ = word1;
633
634
  /* X_PRECISION is special: on the 68k, it has 16 bits of zero in the
635
     middle.  Either way, it is then followed by a 1 bit.  */
636
25.3k
  if (exponent_bits == 15 && precision == X_PRECISION)
637
607
    {
638
#ifdef TC_M68K
639
      *lp++ = 0;
640
#endif
641
607
      *lp++ = (1 << (LITTLENUM_NUMBER_OF_BITS - 1)
642
607
         | next_bits (LITTLENUM_NUMBER_OF_BITS - 1));
643
607
    }
644
645
  /* The rest of the words are just mantissa bits.  */
646
51.9k
  while (lp < words_end)
647
26.5k
    *lp++ = next_bits (LITTLENUM_NUMBER_OF_BITS);
648
649
25.3k
  if (next_bits (1))
650
392
    {
651
392
      unsigned long carry;
652
      /* Since the NEXT bit is a 1, round UP the mantissa.
653
   The cunning design of these hidden-1 floats permits
654
   us to let the mantissa overflow into the exponent, and
655
   it 'does the right thing'. However, we lose if the
656
   highest-order bit of the lowest-order word flips.
657
   Is that clear?  */
658
659
      /* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2)
660
   Please allow at least 1 more bit in carry than is in a LITTLENUM.
661
   We need that extra bit to hold a carry during a LITTLENUM carry
662
   propagation. Another extra bit (kept 0) will assure us that we
663
   don't get a sticky sign bit after shifting right, and that
664
   permits us to propagate the carry without any masking of bits.
665
   #endif */
666
784
      for (carry = 1, lp--; carry; lp--)
667
392
  {
668
392
    carry = *lp + carry;
669
392
    *lp = carry;
670
392
    carry >>= LITTLENUM_NUMBER_OF_BITS;
671
392
    if (lp == words)
672
0
      break;
673
392
  }
674
392
      if (precision == X_PRECISION && exponent_bits == 15)
675
0
  {
676
    /* Extended precision numbers have an explicit integer bit
677
       that we may have to restore.  */
678
0
    if (lp == words)
679
0
      {
680
#ifdef TC_M68K
681
        /* On the m68k there is a gap of 16 bits.  We must
682
     explicitly propagate the carry into the exponent.  */
683
        words[0] += words[1];
684
        words[1] = 0;
685
        lp++;
686
#endif
687
        /* Put back the integer bit.  */
688
0
        lp[1] |= 1 << (LITTLENUM_NUMBER_OF_BITS - 1);
689
0
      }
690
0
  }
691
392
      if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
692
0
  {
693
    /* We leave return_value alone: admit we read the number,
694
       but return a floating exception because we can't encode
695
       the number.  */
696
0
    *words &= ~(1 << (LITTLENUM_NUMBER_OF_BITS - 1));
697
0
  }
698
392
    }
699
25.3k
  return return_value;
700
25.4k
}
701
702
#ifdef TEST
703
char *
704
print_gen (gen)
705
     FLONUM_TYPE *gen;
706
{
707
  FLONUM_TYPE f;
708
  LITTLENUM_TYPE arr[10];
709
  double dv;
710
  float fv;
711
  static char sbuf[40];
712
713
  if (gen)
714
    {
715
      f = generic_floating_point_number;
716
      generic_floating_point_number = *gen;
717
    }
718
  gen_to_words (&arr[0], 4, 11);
719
  memcpy (&dv, &arr[0], sizeof (double));
720
  sprintf (sbuf, "%x %x %x %x %.14G   ", arr[0], arr[1], arr[2], arr[3], dv);
721
  gen_to_words (&arr[0], 2, 8);
722
  memcpy (&fv, &arr[0], sizeof (float));
723
  sprintf (sbuf + strlen (sbuf), "%x %x %.12g\n", arr[0], arr[1], fv);
724
725
  if (gen)
726
    generic_floating_point_number = f;
727
728
  return (sbuf);
729
}
730
#endif
731
732
/* This is a utility function called from various tc-*.c files.  It
733
   is here in order to reduce code duplication.
734
735
   Turn a string at input_line_pointer into a floating point constant
736
   of type TYPE (a character found in the FLT_CHARS macro), and store
737
   it as LITTLENUMS in the bytes buffer LITP.  The number of chars
738
   emitted is stored in *SIZEP.  BIG_WORDIAN is TRUE if the littlenums
739
   should be emitted most significant littlenum first.
740
741
   An error message is returned, or a NULL pointer if everything went OK.  */
742
743
const char *
744
ieee_md_atof (int type,
745
        char *litP,
746
        int *sizeP,
747
        bool big_wordian)
748
35.3k
{
749
35.3k
  LITTLENUM_TYPE words[MAX_LITTLENUMS];
750
35.3k
  LITTLENUM_TYPE *wordP;
751
35.3k
  char *t;
752
35.3k
  int prec = 0, pad = 0;
753
754
35.3k
  if (strchr (FLT_CHARS, type) != NULL)
755
35.3k
    {
756
35.3k
      switch (type)
757
35.3k
  {
758
0
  case 'H':
759
2
  case 'h':
760
2
    prec = H_PRECISION;
761
2
    break;
762
763
0
  case 'B':
764
12
  case 'b':
765
12
    prec = B_PRECISION;
766
12
    break;
767
768
34.7k
  case 'f':
769
34.7k
  case 'F':
770
34.7k
  case 's':
771
34.7k
  case 'S':
772
34.7k
    prec = F_PRECISION;
773
34.7k
    break;
774
775
1
  case 'd':
776
1
  case 'D':
777
1
  case 'r':
778
1
  case 'R':
779
1
    prec = D_PRECISION;
780
1
    break;
781
782
0
  case 't':
783
0
  case 'T':
784
0
    prec = X_PRECISION;
785
0
    pad = X_PRECISION_PAD;
786
0
    type = 'x';   /* This is what atof_ieee() understands.  */
787
0
    break;
788
789
607
  case 'x':
790
607
  case 'X':
791
607
  case 'p':
792
607
  case 'P':
793
#ifdef TC_M68K
794
    /* Note: on the m68k there is a gap of 16 bits (one littlenum)
795
       between the exponent and mantissa.  Hence the precision is
796
       6 and not 5.  */
797
    prec = P_PRECISION + 1;
798
#else
799
607
    prec = P_PRECISION;
800
607
#endif
801
607
    pad = P_PRECISION_PAD;
802
607
    break;
803
804
0
  default:
805
0
    break;
806
35.3k
  }
807
35.3k
    }
808
  /* The 'f' and 'd' types are always recognised, even if the target has
809
     not put them into the FLT_CHARS macro.  This is because the 'f' type
810
     can come from the .dc.s, .dcb.s, .float or .single pseudo-ops and the
811
     'd' type from the .dc.d, .dbc.d or .double pseudo-ops.
812
813
     The 'x' type is not implicitly recognised however, even though it can
814
     be generated by the .dc.x and .dbc.x pseudo-ops because not all targets
815
     can support floating point values that big.  ie the target has to
816
     explicitly allow them by putting them into FLT_CHARS.  */
817
0
  else if (type == 'f')
818
0
    prec = F_PRECISION;
819
0
  else if (type == 'd')
820
0
    prec = D_PRECISION;
821
822
35.3k
  if (prec == 0)
823
0
    {
824
0
      *sizeP = 0;
825
0
      return _("Unrecognized or unsupported floating point constant");
826
0
    }
827
828
35.3k
  gas_assert (prec <= MAX_LITTLENUMS);
829
830
0
  t = atof_ieee (input_line_pointer, type, words);
831
35.3k
  if (t)
832
35.3k
    input_line_pointer = t;
833
834
35.3k
  *sizeP = (prec + pad) * sizeof (LITTLENUM_TYPE);
835
836
35.3k
  if (big_wordian)
837
0
    {
838
0
      for (wordP = words; prec --;)
839
0
  {
840
0
    md_number_to_chars (litP, (valueT) (* wordP ++), sizeof (LITTLENUM_TYPE));
841
0
    litP += sizeof (LITTLENUM_TYPE);
842
0
  }
843
0
    }
844
35.3k
  else
845
35.3k
    {
846
107k
      for (wordP = words + prec; prec --;)
847
72.5k
  {
848
72.5k
    md_number_to_chars (litP, (valueT) (* -- wordP), sizeof (LITTLENUM_TYPE));
849
72.5k
    litP += sizeof (LITTLENUM_TYPE);
850
72.5k
  }
851
35.3k
    }
852
853
35.3k
  memset (litP, 0, pad * sizeof (LITTLENUM_TYPE));
854
35.3k
  litP += pad * sizeof (LITTLENUM_TYPE);
855
856
35.3k
  return NULL;
857
35.3k
}