1 /* Print floating point number in hexadecimal notation according to ISO C99.
2 Copyright (C) 1997-2012 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library 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 GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20 #include <config.h>
21 #include <math.h>
22 #include <stdlib.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <stdbool.h>
26 #define NDEBUG
27 #include <assert.h>
28 #include "quadmath-rounding-mode.h"
29 #include "quadmath-printf.h"
30 #include "_itoa.h"
31 #include "_itowa.h"
32
33
34 /* Macros for doing the actual output. */
35
36 #define outchar(ch) \
37 do \
38 { \
39 register const int outc = (ch); \
40 if (PUTC (outc, fp) == EOF) \
41 return -1; \
42 ++done; \
43 } while (0)
44
45 #define PRINT(ptr, wptr, len) \
46 do \
47 { \
48 register size_t outlen = (len); \
49 if (wide) \
50 while (outlen-- > 0) \
51 outchar (*wptr++); \
52 else \
53 while (outlen-- > 0) \
54 outchar (*ptr++); \
55 } while (0)
56
57 #define PADN(ch, len) \
58 do \
59 { \
60 if (PAD (fp, ch, len) != len) \
61 return -1; \
62 done += len; \
63 } \
64 while (0)
65
66
67
68 int
__quadmath_printf_fphex(struct __quadmath_printf_file * fp,const struct printf_info * info,const void * const * args)69 __quadmath_printf_fphex (struct __quadmath_printf_file *fp,
70 const struct printf_info *info,
71 const void *const *args)
72 {
73 /* The floating-point value to output. */
74 ieee854_float128 fpnum;
75
76 /* Locale-dependent representation of decimal point. */
77 const char *decimal;
78 wchar_t decimalwc;
79
80 /* "NaN" or "Inf" for the special cases. */
81 const char *special = NULL;
82 const wchar_t *wspecial = NULL;
83
84 /* Buffer for the generated number string for the mantissa. The
85 maximal size for the mantissa is 128 bits. */
86 char numbuf[32];
87 char *numstr;
88 char *numend;
89 wchar_t wnumbuf[32];
90 wchar_t *wnumstr;
91 wchar_t *wnumend;
92 int negative;
93
94 /* The maximal exponent of two in decimal notation has 5 digits. */
95 char expbuf[5];
96 char *expstr;
97 wchar_t wexpbuf[5];
98 wchar_t *wexpstr;
99 int expnegative;
100 int exponent;
101
102 /* Non-zero is mantissa is zero. */
103 int zero_mantissa;
104
105 /* The leading digit before the decimal point. */
106 char leading;
107
108 /* Precision. */
109 int precision = info->prec;
110
111 /* Width. */
112 int width = info->width;
113
114 /* Number of characters written. */
115 int done = 0;
116
117 /* Nonzero if this is output on a wide character stream. */
118 int wide = info->wide;
119
120 bool do_round_away;
121
122 /* Figure out the decimal point character. */
123 #ifdef USE_NL_LANGINFO
124 if (info->extra == 0)
125 decimal = nl_langinfo (DECIMAL_POINT);
126 else
127 {
128 decimal = nl_langinfo (MON_DECIMAL_POINT);
129 if (*decimal == '\0')
130 decimal = nl_langinfo (DECIMAL_POINT);
131 }
132 /* The decimal point character must never be zero. */
133 assert (*decimal != '\0');
134 #elif defined USE_LOCALECONV
135 const struct lconv *lc = localeconv ();
136 if (info->extra == 0)
137 decimal = lc->decimal_point;
138 else
139 {
140 decimal = lc->mon_decimal_point;
141 if (decimal == NULL || *decimal == '\0')
142 decimal = lc->decimal_point;
143 }
144 if (decimal == NULL || *decimal == '\0')
145 decimal = ".";
146 #else
147 decimal = ".";
148 #endif
149 #ifdef USE_NL_LANGINFO_WC
150 if (info->extra == 0)
151 decimalwc = nl_langinfo_wc (_NL_NUMERIC_DECIMAL_POINT_WC);
152 else
153 {
154 decimalwc = nl_langinfo_wc (_NL_MONETARY_DECIMAL_POINT_WC);
155 if (decimalwc == L_('\0'))
156 decimalwc = nl_langinfo_wc (_NL_NUMERIC_DECIMAL_POINT_WC);
157 }
158 /* The decimal point character must never be zero. */
159 assert (decimalwc != L_('\0'));
160 #else
161 decimalwc = L_('.');
162 #endif
163
164 /* Fetch the argument value. */
165 {
166 fpnum.value = **(const __float128 **) args[0];
167
168 /* Check for special values: not a number or infinity. */
169 if (isnanq (fpnum.value))
170 {
171 negative = fpnum.ieee.negative != 0;
172 if (isupper (info->spec))
173 {
174 special = "NAN";
175 wspecial = L_("NAN");
176 }
177 else
178 {
179 special = "nan";
180 wspecial = L_("nan");
181 }
182 }
183 else
184 {
185 if (isinfq (fpnum.value))
186 {
187 if (isupper (info->spec))
188 {
189 special = "INF";
190 wspecial = L_("INF");
191 }
192 else
193 {
194 special = "inf";
195 wspecial = L_("inf");
196 }
197 }
198
199 negative = signbitq (fpnum.value);
200 }
201 }
202
203 if (special)
204 {
205 int width = info->width;
206
207 if (negative || info->showsign || info->space)
208 --width;
209 width -= 3;
210
211 if (!info->left && width > 0)
212 PADN (' ', width);
213
214 if (negative)
215 outchar ('-');
216 else if (info->showsign)
217 outchar ('+');
218 else if (info->space)
219 outchar (' ');
220
221 PRINT (special, wspecial, 3);
222
223 if (info->left && width > 0)
224 PADN (' ', width);
225
226 return done;
227 }
228
229 {
230 /* We have 112 bits of mantissa plus one implicit digit. Since
231 112 bits are representable without rest using hexadecimal
232 digits we use only the implicit digits for the number before
233 the decimal point. */
234 uint64_t num0, num1;
235
236 assert (sizeof (long double) == 16);
237
238 num0 = fpnum.ieee.mant_high;
239 num1 = fpnum.ieee.mant_low;
240
241 zero_mantissa = (num0|num1) == 0;
242
243 if (sizeof (unsigned long int) > 6)
244 {
245 numstr = _itoa_word (num1, numbuf + sizeof numbuf, 16,
246 info->spec == 'A');
247 wnumstr = _itowa_word (num1,
248 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),
249 16, info->spec == 'A');
250 }
251 else
252 {
253 numstr = _itoa (num1, numbuf + sizeof numbuf, 16,
254 info->spec == 'A');
255 wnumstr = _itowa (num1,
256 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),
257 16, info->spec == 'A');
258 }
259
260 while (numstr > numbuf + (sizeof numbuf - 64 / 4))
261 {
262 *--numstr = '0';
263 *--wnumstr = L_('0');
264 }
265
266 if (sizeof (unsigned long int) > 6)
267 {
268 numstr = _itoa_word (num0, numstr, 16, info->spec == 'A');
269 wnumstr = _itowa_word (num0, wnumstr, 16, info->spec == 'A');
270 }
271 else
272 {
273 numstr = _itoa (num0, numstr, 16, info->spec == 'A');
274 wnumstr = _itowa (num0, wnumstr, 16, info->spec == 'A');
275 }
276
277 /* Fill with zeroes. */
278 while (numstr > numbuf + (sizeof numbuf - 112 / 4))
279 {
280 *--wnumstr = L_('0');
281 *--numstr = '0';
282 }
283
284 leading = fpnum.ieee.exponent == 0 ? '0' : '1';
285
286 exponent = fpnum.ieee.exponent;
287
288 if (exponent == 0)
289 {
290 if (zero_mantissa)
291 expnegative = 0;
292 else
293 {
294 /* This is a denormalized number. */
295 expnegative = 1;
296 exponent = IEEE854_FLOAT128_BIAS - 1;
297 }
298 }
299 else if (exponent >= IEEE854_FLOAT128_BIAS)
300 {
301 expnegative = 0;
302 exponent -= IEEE854_FLOAT128_BIAS;
303 }
304 else
305 {
306 expnegative = 1;
307 exponent = -(exponent - IEEE854_FLOAT128_BIAS);
308 }
309 }
310
311 /* Look for trailing zeroes. */
312 if (! zero_mantissa)
313 {
314 wnumend = &wnumbuf[sizeof wnumbuf / sizeof wnumbuf[0]];
315 numend = &numbuf[sizeof numbuf / sizeof numbuf[0]];
316 while (wnumend[-1] == L_('0'))
317 {
318 --wnumend;
319 --numend;
320 }
321
322 do_round_away = false;
323
324 if (precision != -1 && precision < numend - numstr)
325 {
326 char last_digit = precision > 0 ? numstr[precision - 1] : leading;
327 char next_digit = numstr[precision];
328 int last_digit_value = (last_digit >= 'A' && last_digit <= 'F'
329 ? last_digit - 'A' + 10
330 : (last_digit >= 'a' && last_digit <= 'f'
331 ? last_digit - 'a' + 10
332 : last_digit - '0'));
333 int next_digit_value = (next_digit >= 'A' && next_digit <= 'F'
334 ? next_digit - 'A' + 10
335 : (next_digit >= 'a' && next_digit <= 'f'
336 ? next_digit - 'a' + 10
337 : next_digit - '0'));
338 bool more_bits = ((next_digit_value & 7) != 0
339 || precision + 1 < numend - numstr);
340 #ifdef HAVE_FENV_H
341 int rounding_mode = get_rounding_mode ();
342 do_round_away = round_away (negative, last_digit_value & 1,
343 next_digit_value >= 8, more_bits,
344 rounding_mode);
345 #endif
346 }
347
348 if (precision == -1)
349 precision = numend - numstr;
350 else if (do_round_away)
351 {
352 /* Round up. */
353 int cnt = precision;
354 while (--cnt >= 0)
355 {
356 char ch = numstr[cnt];
357 /* We assume that the digits and the letters are ordered
358 like in ASCII. This is true for the rest of GNU, too. */
359 if (ch == '9')
360 {
361 wnumstr[cnt] = (wchar_t) info->spec;
362 numstr[cnt] = info->spec; /* This is tricky,
363 think about it! */
364 break;
365 }
366 else if (tolower (ch) < 'f')
367 {
368 ++numstr[cnt];
369 ++wnumstr[cnt];
370 break;
371 }
372 else
373 {
374 numstr[cnt] = '0';
375 wnumstr[cnt] = L_('0');
376 }
377 }
378 if (cnt < 0)
379 {
380 /* The mantissa so far was fff...f Now increment the
381 leading digit. Here it is again possible that we
382 get an overflow. */
383 if (leading == '9')
384 leading = info->spec;
385 else if (tolower (leading) < 'f')
386 ++leading;
387 else
388 {
389 leading = '1';
390 if (expnegative)
391 {
392 exponent -= 4;
393 if (exponent <= 0)
394 {
395 exponent = -exponent;
396 expnegative = 0;
397 }
398 }
399 else
400 exponent += 4;
401 }
402 }
403 }
404 }
405 else
406 {
407 if (precision == -1)
408 precision = 0;
409 numend = numstr;
410 wnumend = wnumstr;
411 }
412
413 /* Now we can compute the exponent string. */
414 expstr = _itoa_word (exponent, expbuf + sizeof expbuf, 10, 0);
415 wexpstr = _itowa_word (exponent,
416 wexpbuf + sizeof wexpbuf / sizeof (wchar_t), 10, 0);
417
418 /* Now we have all information to compute the size. */
419 width -= ((negative || info->showsign || info->space)
420 /* Sign. */
421 + 2 + 1 + 0 + precision + 1 + 1
422 /* 0x h . hhh P ExpoSign. */
423 + ((expbuf + sizeof expbuf) - expstr));
424 /* Exponent. */
425
426 /* Count the decimal point.
427 A special case when the mantissa or the precision is zero and the `#'
428 is not given. In this case we must not print the decimal point. */
429 if (precision > 0 || info->alt)
430 width -= wide ? 1 : strlen (decimal);
431
432 if (!info->left && info->pad != '0' && width > 0)
433 PADN (' ', width);
434
435 if (negative)
436 outchar ('-');
437 else if (info->showsign)
438 outchar ('+');
439 else if (info->space)
440 outchar (' ');
441
442 outchar ('0');
443 if ('X' - 'A' == 'x' - 'a')
444 outchar (info->spec + ('x' - 'a'));
445 else
446 outchar (info->spec == 'A' ? 'X' : 'x');
447
448 if (!info->left && info->pad == '0' && width > 0)
449 PADN ('0', width);
450
451 outchar (leading);
452
453 if (precision > 0 || info->alt)
454 {
455 const wchar_t *wtmp = &decimalwc;
456 PRINT (decimal, wtmp, wide ? 1 : strlen (decimal));
457 }
458
459 if (precision > 0)
460 {
461 ssize_t tofill = precision - (numend - numstr);
462 PRINT (numstr, wnumstr, MIN (numend - numstr, precision));
463 if (tofill > 0)
464 PADN ('0', tofill);
465 }
466
467 if ('P' - 'A' == 'p' - 'a')
468 outchar (info->spec + ('p' - 'a'));
469 else
470 outchar (info->spec == 'A' ? 'P' : 'p');
471
472 outchar (expnegative ? '-' : '+');
473
474 PRINT (expstr, wexpstr, (expbuf + sizeof expbuf) - expstr);
475
476 if (info->left && info->pad != '0' && width > 0)
477 PADN (info->pad, width);
478
479 return done;
480 }
481