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
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 = (((unsigned long long int) fpnum.ieee.mantissa0) << 32
239 | fpnum.ieee.mantissa1);
240 num1 = (((unsigned long long int) fpnum.ieee.mantissa2) << 32
241 | fpnum.ieee.mantissa3);
242
243 zero_mantissa = (num0|num1) == 0;
244
245 if (sizeof (unsigned long int) > 6)
246 {
247 numstr = _itoa_word (num1, numbuf + sizeof numbuf, 16,
248 info->spec == 'A');
249 wnumstr = _itowa_word (num1,
250 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),
251 16, info->spec == 'A');
252 }
253 else
254 {
255 numstr = _itoa (num1, numbuf + sizeof numbuf, 16,
256 info->spec == 'A');
257 wnumstr = _itowa (num1,
258 wnumbuf + sizeof (wnumbuf) / sizeof (wchar_t),
259 16, info->spec == 'A');
260 }
261
262 while (numstr > numbuf + (sizeof numbuf - 64 / 4))
263 {
264 *--numstr = '0';
265 *--wnumstr = L_('0');
266 }
267
268 if (sizeof (unsigned long int) > 6)
269 {
270 numstr = _itoa_word (num0, numstr, 16, info->spec == 'A');
271 wnumstr = _itowa_word (num0, wnumstr, 16, info->spec == 'A');
272 }
273 else
274 {
275 numstr = _itoa (num0, numstr, 16, info->spec == 'A');
276 wnumstr = _itowa (num0, wnumstr, 16, info->spec == 'A');
277 }
278
279 /* Fill with zeroes. */
280 while (numstr > numbuf + (sizeof numbuf - 112 / 4))
281 {
282 *--wnumstr = L_('0');
283 *--numstr = '0';
284 }
285
286 leading = fpnum.ieee.exponent == 0 ? '0' : '1';
287
288 exponent = fpnum.ieee.exponent;
289
290 if (exponent == 0)
291 {
292 if (zero_mantissa)
293 expnegative = 0;
294 else
295 {
296 /* This is a denormalized number. */
297 expnegative = 1;
298 exponent = IEEE854_FLOAT128_BIAS - 1;
299 }
300 }
301 else if (exponent >= IEEE854_FLOAT128_BIAS)
302 {
303 expnegative = 0;
304 exponent -= IEEE854_FLOAT128_BIAS;
305 }
306 else
307 {
308 expnegative = 1;
309 exponent = -(exponent - IEEE854_FLOAT128_BIAS);
310 }
311 }
312
313 /* Look for trailing zeroes. */
314 if (! zero_mantissa)
315 {
316 wnumend = &wnumbuf[sizeof wnumbuf / sizeof wnumbuf[0]];
317 numend = &numbuf[sizeof numbuf / sizeof numbuf[0]];
318 while (wnumend[-1] == L_('0'))
319 {
320 --wnumend;
321 --numend;
322 }
323
324 do_round_away = false;
325
326 if (precision != -1 && precision < numend - numstr)
327 {
328 char last_digit = precision > 0 ? numstr[precision - 1] : leading;
329 char next_digit = numstr[precision];
330 int last_digit_value = (last_digit >= 'A' && last_digit <= 'F'
331 ? last_digit - 'A' + 10
332 : (last_digit >= 'a' && last_digit <= 'f'
333 ? last_digit - 'a' + 10
334 : last_digit - '0'));
335 int next_digit_value = (next_digit >= 'A' && next_digit <= 'F'
336 ? next_digit - 'A' + 10
337 : (next_digit >= 'a' && next_digit <= 'f'
338 ? next_digit - 'a' + 10
339 : next_digit - '0'));
340 bool more_bits = ((next_digit_value & 7) != 0
341 || precision + 1 < numend - numstr);
342 #ifdef HAVE_FENV_H
343 int rounding_mode = get_rounding_mode ();
344 do_round_away = round_away (negative, last_digit_value & 1,
345 next_digit_value >= 8, more_bits,
346 rounding_mode);
347 #endif
348 }
349
350 if (precision == -1)
351 precision = numend - numstr;
352 else if (do_round_away)
353 {
354 /* Round up. */
355 int cnt = precision;
356 while (--cnt >= 0)
357 {
358 char ch = numstr[cnt];
359 /* We assume that the digits and the letters are ordered
360 like in ASCII. This is true for the rest of GNU, too. */
361 if (ch == '9')
362 {
363 wnumstr[cnt] = (wchar_t) info->spec;
364 numstr[cnt] = info->spec; /* This is tricky,
365 think about it! */
366 break;
367 }
368 else if (tolower (ch) < 'f')
369 {
370 ++numstr[cnt];
371 ++wnumstr[cnt];
372 break;
373 }
374 else
375 {
376 numstr[cnt] = '0';
377 wnumstr[cnt] = L_('0');
378 }
379 }
380 if (cnt < 0)
381 {
382 /* The mantissa so far was fff...f Now increment the
383 leading digit. Here it is again possible that we
384 get an overflow. */
385 if (leading == '9')
386 leading = info->spec;
387 else if (tolower (leading) < 'f')
388 ++leading;
389 else
390 {
391 leading = '1';
392 if (expnegative)
393 {
394 exponent -= 4;
395 if (exponent <= 0)
396 {
397 exponent = -exponent;
398 expnegative = 0;
399 }
400 }
401 else
402 exponent += 4;
403 }
404 }
405 }
406 }
407 else
408 {
409 if (precision == -1)
410 precision = 0;
411 numend = numstr;
412 wnumend = wnumstr;
413 }
414
415 /* Now we can compute the exponent string. */
416 expstr = _itoa_word (exponent, expbuf + sizeof expbuf, 10, 0);
417 wexpstr = _itowa_word (exponent,
418 wexpbuf + sizeof wexpbuf / sizeof (wchar_t), 10, 0);
419
420 /* Now we have all information to compute the size. */
421 width -= ((negative || info->showsign || info->space)
422 /* Sign. */
423 + 2 + 1 + 0 + precision + 1 + 1
424 /* 0x h . hhh P ExpoSign. */
425 + ((expbuf + sizeof expbuf) - expstr));
426 /* Exponent. */
427
428 /* Count the decimal point.
429 A special case when the mantissa or the precision is zero and the `#'
430 is not given. In this case we must not print the decimal point. */
431 if (precision > 0 || info->alt)
432 width -= wide ? 1 : strlen (decimal);
433
434 if (!info->left && info->pad != '0' && width > 0)
435 PADN (' ', width);
436
437 if (negative)
438 outchar ('-');
439 else if (info->showsign)
440 outchar ('+');
441 else if (info->space)
442 outchar (' ');
443
444 outchar ('0');
445 if ('X' - 'A' == 'x' - 'a')
446 outchar (info->spec + ('x' - 'a'));
447 else
448 outchar (info->spec == 'A' ? 'X' : 'x');
449
450 if (!info->left && info->pad == '0' && width > 0)
451 PADN ('0', width);
452
453 outchar (leading);
454
455 if (precision > 0 || info->alt)
456 {
457 const wchar_t *wtmp = &decimalwc;
458 PRINT (decimal, wtmp, wide ? 1 : strlen (decimal));
459 }
460
461 if (precision > 0)
462 {
463 ssize_t tofill = precision - (numend - numstr);
464 PRINT (numstr, wnumstr, MIN (numend - numstr, precision));
465 if (tofill > 0)
466 PADN ('0', tofill);
467 }
468
469 if ('P' - 'A' == 'p' - 'a')
470 outchar (info->spec + ('p' - 'a'));
471 else
472 outchar (info->spec == 'A' ? 'P' : 'p');
473
474 outchar (expnegative ? '-' : '+');
475
476 PRINT (expstr, wexpstr, (expbuf + sizeof expbuf) - expstr);
477
478 if (info->left && info->pad != '0' && width > 0)
479 PADN (info->pad, width);
480
481 return done;
482 }