1 | /* Print floating point number in hexadecimal notation according to ISO C99. |
2 | Copyright (C) 1997-2017 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 <ctype.h> |
21 | #include <ieee754.h> |
22 | #include <math.h> |
23 | #include <printf.h> |
24 | #include <stdlib.h> |
25 | #include <stdio.h> |
26 | #include <string.h> |
27 | #include <wchar.h> |
28 | #include <_itoa.h> |
29 | #include <_itowa.h> |
30 | #include <locale/localeinfo.h> |
31 | #include <stdbool.h> |
32 | #include <rounding-mode.h> |
33 | |
34 | #if __HAVE_DISTINCT_FLOAT128 |
35 | # include "ieee754_float128.h" |
36 | # include <ldbl-128/printf_fphex_macros.h> |
37 | # define PRINT_FPHEX_FLOAT128 \ |
38 | PRINT_FPHEX (_Float128, fpnum.flt128, ieee854_float128, \ |
39 | IEEE854_FLOAT128_BIAS) |
40 | #endif |
41 | |
42 | /* #define NDEBUG 1*/ /* Undefine this for debugging assertions. */ |
43 | #include <assert.h> |
44 | |
45 | /* This defines make it possible to use the same code for GNU C library and |
46 | the GNU I/O library. */ |
47 | #include <libioP.h> |
48 | #define PUT(f, s, n) _IO_sputn (f, s, n) |
49 | #define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n)) |
50 | /* We use this file GNU C library and GNU I/O library. So make |
51 | names equal. */ |
52 | #undef putc |
53 | #define putc(c, f) (wide \ |
54 | ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f)) |
55 | #define size_t _IO_size_t |
56 | #define FILE _IO_FILE |
57 | |
58 | /* Macros for doing the actual output. */ |
59 | |
60 | #define outchar(ch) \ |
61 | do \ |
62 | { \ |
63 | const int outc = (ch); \ |
64 | if (putc (outc, fp) == EOF) \ |
65 | return -1; \ |
66 | ++done; \ |
67 | } while (0) |
68 | |
69 | #define PRINT(ptr, wptr, len) \ |
70 | do \ |
71 | { \ |
72 | size_t outlen = (len); \ |
73 | if (wide) \ |
74 | while (outlen-- > 0) \ |
75 | outchar (*wptr++); \ |
76 | else \ |
77 | while (outlen-- > 0) \ |
78 | outchar (*ptr++); \ |
79 | } while (0) |
80 | |
81 | #define PADN(ch, len) \ |
82 | do \ |
83 | { \ |
84 | if (PAD (fp, ch, len) != len) \ |
85 | return -1; \ |
86 | done += len; \ |
87 | } \ |
88 | while (0) |
89 | |
90 | #ifndef MIN |
91 | # define MIN(a,b) ((a)<(b)?(a):(b)) |
92 | #endif |
93 | |
94 | |
95 | int |
96 | __printf_fphex (FILE *fp, |
97 | const struct printf_info *info, |
98 | const void *const *args) |
99 | { |
100 | /* The floating-point value to output. */ |
101 | union |
102 | { |
103 | union ieee754_double dbl; |
104 | long double ldbl; |
105 | #if __HAVE_DISTINCT_FLOAT128 |
106 | _Float128 flt128; |
107 | #endif |
108 | } |
109 | fpnum; |
110 | |
111 | /* Locale-dependent representation of decimal point. */ |
112 | const char *decimal; |
113 | wchar_t decimalwc; |
114 | |
115 | /* "NaN" or "Inf" for the special cases. */ |
116 | const char *special = NULL; |
117 | const wchar_t *wspecial = NULL; |
118 | |
119 | /* Buffer for the generated number string for the mantissa. The |
120 | maximal size for the mantissa is 128 bits. */ |
121 | char numbuf[32]; |
122 | char *numstr; |
123 | char *numend; |
124 | wchar_t wnumbuf[32]; |
125 | wchar_t *wnumstr; |
126 | wchar_t *wnumend; |
127 | int negative; |
128 | |
129 | /* The maximal exponent of two in decimal notation has 5 digits. */ |
130 | char expbuf[5]; |
131 | char *expstr; |
132 | wchar_t wexpbuf[5]; |
133 | wchar_t *wexpstr; |
134 | int expnegative; |
135 | int exponent; |
136 | |
137 | /* Non-zero is mantissa is zero. */ |
138 | int zero_mantissa; |
139 | |
140 | /* The leading digit before the decimal point. */ |
141 | char leading; |
142 | |
143 | /* Precision. */ |
144 | int precision = info->prec; |
145 | |
146 | /* Width. */ |
147 | int width = info->width; |
148 | |
149 | /* Number of characters written. */ |
150 | int done = 0; |
151 | |
152 | /* Nonzero if this is output on a wide character stream. */ |
153 | int wide = info->wide; |
154 | |
155 | |
156 | /* Figure out the decimal point character. */ |
157 | if (info->extra == 0) |
158 | { |
159 | decimal = _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT); |
160 | decimalwc = _NL_CURRENT_WORD (LC_NUMERIC, _NL_NUMERIC_DECIMAL_POINT_WC); |
161 | } |
162 | else |
163 | { |
164 | decimal = _NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT); |
165 | decimalwc = _NL_CURRENT_WORD (LC_MONETARY, |
166 | _NL_MONETARY_DECIMAL_POINT_WC); |
167 | } |
168 | /* The decimal point character must never be zero. */ |
169 | assert (*decimal != '\0' && decimalwc != L'\0'); |
170 | |
171 | #define PRINTF_FPHEX_FETCH(FLOAT, VAR) \ |
172 | { \ |
173 | (VAR) = *(const FLOAT *) args[0]; \ |
174 | \ |
175 | /* Check for special values: not a number or infinity. */ \ |
176 | if (isnan (VAR)) \ |
177 | { \ |
178 | if (isupper (info->spec)) \ |
179 | { \ |
180 | special = "NAN"; \ |
181 | wspecial = L"NAN"; \ |
182 | } \ |
183 | else \ |
184 | { \ |
185 | special = "nan"; \ |
186 | wspecial = L"nan"; \ |
187 | } \ |
188 | } \ |
189 | else \ |
190 | { \ |
191 | if (isinf (VAR)) \ |
192 | { \ |
193 | if (isupper (info->spec)) \ |
194 | { \ |
195 | special = "INF"; \ |
196 | wspecial = L"INF"; \ |
197 | } \ |
198 | else \ |
199 | { \ |
200 | special = "inf"; \ |
201 | wspecial = L"inf"; \ |
202 | } \ |
203 | } \ |
204 | } \ |
205 | negative = signbit (VAR); \ |
206 | } |
207 | |
208 | /* Fetch the argument value. */ |
209 | #if __HAVE_DISTINCT_FLOAT128 |
210 | if (info->is_binary128) |
211 | PRINTF_FPHEX_FETCH (_Float128, fpnum.flt128) |
212 | else |
213 | #endif |
214 | #ifndef __NO_LONG_DOUBLE_MATH |
215 | if (info->is_long_double && sizeof (long double) > sizeof (double)) |
216 | PRINTF_FPHEX_FETCH (long double, fpnum.ldbl) |
217 | else |
218 | #endif |
219 | PRINTF_FPHEX_FETCH (double, fpnum.dbl.d) |
220 | |
221 | #undef PRINTF_FPHEX_FETCH |
222 | |
223 | if (special) |
224 | { |
225 | int width = info->width; |
226 | |
227 | if (negative || info->showsign || info->space) |
228 | --width; |
229 | width -= 3; |
230 | |
231 | if (!info->left && width > 0) |
232 | PADN (' ', width); |
233 | |
234 | if (negative) |
235 | outchar ('-'); |
236 | else if (info->showsign) |
237 | outchar ('+'); |
238 | else if (info->space) |
239 | outchar (' '); |
240 | |
241 | PRINT (special, wspecial, 3); |
242 | |
243 | if (info->left && width > 0) |
244 | PADN (' ', width); |
245 | |
246 | return done; |
247 | } |
248 | |
249 | #if __HAVE_DISTINCT_FLOAT128 |
250 | if (info->is_binary128) |
251 | PRINT_FPHEX_FLOAT128; |
252 | else |
253 | #endif |
254 | if (info->is_long_double == 0 || sizeof (double) == sizeof (long double)) |
255 | { |
256 | /* We have 52 bits of mantissa plus one implicit digit. Since |
257 | 52 bits are representable without rest using hexadecimal |
258 | digits we use only the implicit digits for the number before |
259 | the decimal point. */ |
260 | unsigned long long int num; |
261 | |
262 | num = (((unsigned long long int) fpnum.dbl.ieee.mantissa0) << 32 |
263 | | fpnum.dbl.ieee.mantissa1); |
264 | |
265 | zero_mantissa = num == 0; |
266 | |
267 | if (sizeof (unsigned long int) > 6) |
268 | { |
269 | wnumstr = _itowa_word (num, wnumbuf + (sizeof wnumbuf) / sizeof (wchar_t), 16, |
270 | info->spec == 'A'); |
271 | numstr = _itoa_word (num, numbuf + sizeof numbuf, 16, |
272 | info->spec == 'A'); |
273 | } |
274 | else |
275 | { |
276 | wnumstr = _itowa (num, wnumbuf + sizeof wnumbuf / sizeof (wchar_t), 16, |
277 | info->spec == 'A'); |
278 | numstr = _itoa (num, numbuf + sizeof numbuf, 16, |
279 | info->spec == 'A'); |
280 | } |
281 | |
282 | /* Fill with zeroes. */ |
283 | while (wnumstr > wnumbuf + (sizeof wnumbuf - 52) / sizeof (wchar_t)) |
284 | { |
285 | *--wnumstr = L'0'; |
286 | *--numstr = '0'; |
287 | } |
288 | |
289 | leading = fpnum.dbl.ieee.exponent == 0 ? '0' : '1'; |
290 | |
291 | exponent = fpnum.dbl.ieee.exponent; |
292 | |
293 | if (exponent == 0) |
294 | { |
295 | if (zero_mantissa) |
296 | expnegative = 0; |
297 | else |
298 | { |
299 | /* This is a denormalized number. */ |
300 | expnegative = 1; |
301 | exponent = IEEE754_DOUBLE_BIAS - 1; |
302 | } |
303 | } |
304 | else if (exponent >= IEEE754_DOUBLE_BIAS) |
305 | { |
306 | expnegative = 0; |
307 | exponent -= IEEE754_DOUBLE_BIAS; |
308 | } |
309 | else |
310 | { |
311 | expnegative = 1; |
312 | exponent = -(exponent - IEEE754_DOUBLE_BIAS); |
313 | } |
314 | } |
315 | #ifdef PRINT_FPHEX_LONG_DOUBLE |
316 | else |
317 | PRINT_FPHEX_LONG_DOUBLE; |
318 | #endif |
319 | |
320 | /* Look for trailing zeroes. */ |
321 | if (! zero_mantissa) |
322 | { |
323 | wnumend = &wnumbuf[sizeof wnumbuf / sizeof wnumbuf[0]]; |
324 | numend = &numbuf[sizeof numbuf / sizeof numbuf[0]]; |
325 | while (wnumend[-1] == L'0') |
326 | { |
327 | --wnumend; |
328 | --numend; |
329 | } |
330 | |
331 | bool do_round_away = false; |
332 | |
333 | if (precision != -1 && precision < numend - numstr) |
334 | { |
335 | char last_digit = precision > 0 ? numstr[precision - 1] : leading; |
336 | char next_digit = numstr[precision]; |
337 | int last_digit_value = (last_digit >= 'A' && last_digit <= 'F' |
338 | ? last_digit - 'A' + 10 |
339 | : (last_digit >= 'a' && last_digit <= 'f' |
340 | ? last_digit - 'a' + 10 |
341 | : last_digit - '0')); |
342 | int next_digit_value = (next_digit >= 'A' && next_digit <= 'F' |
343 | ? next_digit - 'A' + 10 |
344 | : (next_digit >= 'a' && next_digit <= 'f' |
345 | ? next_digit - 'a' + 10 |
346 | : next_digit - '0')); |
347 | bool more_bits = ((next_digit_value & 7) != 0 |
348 | || precision + 1 < numend - numstr); |
349 | int rounding_mode = get_rounding_mode (); |
350 | do_round_away = round_away (negative, last_digit_value & 1, |
351 | next_digit_value >= 8, more_bits, |
352 | rounding_mode); |
353 | } |
354 | |
355 | if (precision == -1) |
356 | precision = numend - numstr; |
357 | else if (do_round_away) |
358 | { |
359 | /* Round up. */ |
360 | int cnt = precision; |
361 | while (--cnt >= 0) |
362 | { |
363 | char ch = numstr[cnt]; |
364 | /* We assume that the digits and the letters are ordered |
365 | like in ASCII. This is true for the rest of GNU, too. */ |
366 | if (ch == '9') |
367 | { |
368 | wnumstr[cnt] = (wchar_t) info->spec; |
369 | numstr[cnt] = info->spec; /* This is tricky, |
370 | think about it! */ |
371 | break; |
372 | } |
373 | else if (tolower (ch) < 'f') |
374 | { |
375 | ++numstr[cnt]; |
376 | ++wnumstr[cnt]; |
377 | break; |
378 | } |
379 | else |
380 | { |
381 | numstr[cnt] = '0'; |
382 | wnumstr[cnt] = L'0'; |
383 | } |
384 | } |
385 | if (cnt < 0) |
386 | { |
387 | /* The mantissa so far was fff...f Now increment the |
388 | leading digit. Here it is again possible that we |
389 | get an overflow. */ |
390 | if (leading == '9') |
391 | leading = info->spec; |
392 | else if (tolower (leading) < 'f') |
393 | ++leading; |
394 | else |
395 | { |
396 | leading = '1'; |
397 | if (expnegative) |
398 | { |
399 | exponent -= 4; |
400 | if (exponent <= 0) |
401 | { |
402 | exponent = -exponent; |
403 | expnegative = 0; |
404 | } |
405 | } |
406 | else |
407 | exponent += 4; |
408 | } |
409 | } |
410 | } |
411 | } |
412 | else |
413 | { |
414 | if (precision == -1) |
415 | precision = 0; |
416 | numend = numstr; |
417 | wnumend = wnumstr; |
418 | } |
419 | |
420 | /* Now we can compute the exponent string. */ |
421 | expstr = _itoa_word (exponent, expbuf + sizeof expbuf, 10, 0); |
422 | wexpstr = _itowa_word (exponent, |
423 | wexpbuf + sizeof wexpbuf / sizeof (wchar_t), 10, 0); |
424 | |
425 | /* Now we have all information to compute the size. */ |
426 | width -= ((negative || info->showsign || info->space) |
427 | /* Sign. */ |
428 | + 2 + 1 + 0 + precision + 1 + 1 |
429 | /* 0x h . hhh P ExpoSign. */ |
430 | + ((expbuf + sizeof expbuf) - expstr)); |
431 | /* Exponent. */ |
432 | |
433 | /* Count the decimal point. |
434 | A special case when the mantissa or the precision is zero and the `#' |
435 | is not given. In this case we must not print the decimal point. */ |
436 | if (precision > 0 || info->alt) |
437 | width -= wide ? 1 : strlen (decimal); |
438 | |
439 | if (!info->left && info->pad != '0' && width > 0) |
440 | PADN (' ', width); |
441 | |
442 | if (negative) |
443 | outchar ('-'); |
444 | else if (info->showsign) |
445 | outchar ('+'); |
446 | else if (info->space) |
447 | outchar (' '); |
448 | |
449 | outchar ('0'); |
450 | if ('X' - 'A' == 'x' - 'a') |
451 | outchar (info->spec + ('x' - 'a')); |
452 | else |
453 | outchar (info->spec == 'A' ? 'X' : 'x'); |
454 | |
455 | if (!info->left && info->pad == '0' && width > 0) |
456 | PADN ('0', width); |
457 | |
458 | outchar (leading); |
459 | |
460 | if (precision > 0 || info->alt) |
461 | { |
462 | const wchar_t *wtmp = &decimalwc; |
463 | PRINT (decimal, wtmp, wide ? 1 : strlen (decimal)); |
464 | } |
465 | |
466 | if (precision > 0) |
467 | { |
468 | ssize_t tofill = precision - (numend - numstr); |
469 | PRINT (numstr, wnumstr, MIN (numend - numstr, precision)); |
470 | if (tofill > 0) |
471 | PADN ('0', tofill); |
472 | } |
473 | |
474 | if ('P' - 'A' == 'p' - 'a') |
475 | outchar (info->spec + ('p' - 'a')); |
476 | else |
477 | outchar (info->spec == 'A' ? 'P' : 'p'); |
478 | |
479 | outchar (expnegative ? '-' : '+'); |
480 | |
481 | PRINT (expstr, wexpstr, (expbuf + sizeof expbuf) - expstr); |
482 | |
483 | if (info->left && info->pad != '0' && width > 0) |
484 | PADN (info->pad, width); |
485 | |
486 | return done; |
487 | } |
488 | |