1 /* Print floating point number in hexadecimal notation according to ISO C99.
2 Copyright (C) 1997-2019 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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.
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.
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 <https://www.gnu.org/licenses/>. */
20 #include <array_length.h>
31 #include <locale/localeinfo.h>
33 #include <rounding-mode.h>
35 #if __HAVE_DISTINCT_FLOAT128
36 # include "ieee754_float128.h"
37 # include <ldbl-128/printf_fphex_macros.h>
38 # define PRINT_FPHEX_FLOAT128 \
39 PRINT_FPHEX (_Float128, fpnum.flt128, ieee854_float128, \
40 IEEE854_FLOAT128_BIAS)
43 /* #define NDEBUG 1*/ /* Undefine this for debugging assertions. */
47 #define PUT(f, s, n) _IO_sputn (f, s, n)
48 #define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
50 #define putc(c, f) (wide \
51 ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
54 /* Macros for doing the actual output. */
59 const int outc = (ch); \
60 if (putc (outc, fp) == EOF) \
65 #define PRINT(ptr, wptr, len) \
68 size_t outlen = (len); \
70 while (outlen-- > 0) \
73 while (outlen-- > 0) \
77 #define PADN(ch, len) \
80 if (PAD (fp, ch, len) != len) \
87 # define MIN(a,b) ((a)<(b)?(a):(b))
92 __printf_fphex (FILE *fp
,
93 const struct printf_info
*info
,
94 const void *const *args
)
96 /* The floating-point value to output. */
99 union ieee754_double dbl
;
101 #if __HAVE_DISTINCT_FLOAT128
107 /* Locale-dependent representation of decimal point. */
111 /* "NaN" or "Inf" for the special cases. */
112 const char *special
= NULL
;
113 const wchar_t *wspecial
= NULL
;
115 /* Buffer for the generated number string for the mantissa. The
116 maximal size for the mantissa is 128 bits. */
125 /* The maximal exponent of two in decimal notation has 5 digits. */
133 /* Non-zero is mantissa is zero. */
136 /* The leading digit before the decimal point. */
140 int precision
= info
->prec
;
143 int width
= info
->width
;
145 /* Number of characters written. */
148 /* Nonzero if this is output on a wide character stream. */
149 int wide
= info
->wide
;
152 /* Figure out the decimal point character. */
153 if (info
->extra
== 0)
155 decimal
= _NL_CURRENT (LC_NUMERIC
, DECIMAL_POINT
);
156 decimalwc
= _NL_CURRENT_WORD (LC_NUMERIC
, _NL_NUMERIC_DECIMAL_POINT_WC
);
160 decimal
= _NL_CURRENT (LC_MONETARY
, MON_DECIMAL_POINT
);
161 decimalwc
= _NL_CURRENT_WORD (LC_MONETARY
,
162 _NL_MONETARY_DECIMAL_POINT_WC
);
164 /* The decimal point character must never be zero. */
165 assert (*decimal
!= '\0' && decimalwc
!= L
'\0');
167 #define PRINTF_FPHEX_FETCH(FLOAT, VAR) \
169 (VAR) = *(const FLOAT *) args[0]; \
171 /* Check for special values: not a number or infinity. */ \
174 if (isupper (info->spec)) \
189 if (isupper (info->spec)) \
201 negative = signbit (VAR); \
204 /* Fetch the argument value. */
205 #if __HAVE_DISTINCT_FLOAT128
206 if (info
->is_binary128
)
207 PRINTF_FPHEX_FETCH (_Float128
, fpnum
.flt128
)
210 #ifndef __NO_LONG_DOUBLE_MATH
211 if (info
->is_long_double
&& sizeof (long double) > sizeof (double))
212 PRINTF_FPHEX_FETCH (long double, fpnum
.ldbl
)
215 PRINTF_FPHEX_FETCH (double, fpnum
.dbl
.d
)
217 #undef PRINTF_FPHEX_FETCH
221 int width
= info
->width
;
223 if (negative
|| info
->showsign
|| info
->space
)
227 if (!info
->left
&& width
> 0)
232 else if (info
->showsign
)
234 else if (info
->space
)
237 PRINT (special
, wspecial
, 3);
239 if (info
->left
&& width
> 0)
245 #if __HAVE_DISTINCT_FLOAT128
246 if (info
->is_binary128
)
247 PRINT_FPHEX_FLOAT128
;
250 if (info
->is_long_double
== 0 || sizeof (double) == sizeof (long double))
252 /* We have 52 bits of mantissa plus one implicit digit. Since
253 52 bits are representable without rest using hexadecimal
254 digits we use only the implicit digits for the number before
255 the decimal point. */
256 unsigned long long int num
;
258 num
= (((unsigned long long int) fpnum
.dbl
.ieee
.mantissa0
) << 32
259 | fpnum
.dbl
.ieee
.mantissa1
);
261 zero_mantissa
= num
== 0;
263 if (sizeof (unsigned long int) > 6)
265 wnumstr
= _itowa_word (num
, wnumbuf
+ (sizeof wnumbuf
) / sizeof (wchar_t), 16,
267 numstr
= _itoa_word (num
, numbuf
+ sizeof numbuf
, 16,
272 wnumstr
= _itowa (num
, wnumbuf
+ sizeof wnumbuf
/ sizeof (wchar_t), 16,
274 numstr
= _itoa (num
, numbuf
+ sizeof numbuf
, 16,
278 /* Fill with zeroes. */
279 while (wnumstr
> wnumbuf
+ (sizeof wnumbuf
- 52) / sizeof (wchar_t))
285 leading
= fpnum
.dbl
.ieee
.exponent
== 0 ? '0' : '1';
287 exponent
= fpnum
.dbl
.ieee
.exponent
;
295 /* This is a denormalized number. */
297 exponent
= IEEE754_DOUBLE_BIAS
- 1;
300 else if (exponent
>= IEEE754_DOUBLE_BIAS
)
303 exponent
-= IEEE754_DOUBLE_BIAS
;
308 exponent
= -(exponent
- IEEE754_DOUBLE_BIAS
);
311 #ifdef PRINT_FPHEX_LONG_DOUBLE
313 PRINT_FPHEX_LONG_DOUBLE
;
316 /* Look for trailing zeroes. */
319 wnumend
= array_end (wnumbuf
);
320 numend
= array_end (numbuf
);
321 while (wnumend
[-1] == L
'0')
327 bool do_round_away
= false;
329 if (precision
!= -1 && precision
< numend
- numstr
)
331 char last_digit
= precision
> 0 ? numstr
[precision
- 1] : leading
;
332 char next_digit
= numstr
[precision
];
333 int last_digit_value
= (last_digit
>= 'A' && last_digit
<= 'F'
334 ? last_digit
- 'A' + 10
335 : (last_digit
>= 'a' && last_digit
<= 'f'
336 ? last_digit
- 'a' + 10
337 : last_digit
- '0'));
338 int next_digit_value
= (next_digit
>= 'A' && next_digit
<= 'F'
339 ? next_digit
- 'A' + 10
340 : (next_digit
>= 'a' && next_digit
<= 'f'
341 ? next_digit
- 'a' + 10
342 : next_digit
- '0'));
343 bool more_bits
= ((next_digit_value
& 7) != 0
344 || precision
+ 1 < numend
- numstr
);
345 int rounding_mode
= get_rounding_mode ();
346 do_round_away
= round_away (negative
, last_digit_value
& 1,
347 next_digit_value
>= 8, more_bits
,
352 precision
= numend
- numstr
;
353 else if (do_round_away
)
359 char ch
= numstr
[cnt
];
360 /* We assume that the digits and the letters are ordered
361 like in ASCII. This is true for the rest of GNU, too. */
364 wnumstr
[cnt
] = (wchar_t) info
->spec
;
365 numstr
[cnt
] = info
->spec
; /* This is tricky,
369 else if (tolower (ch
) < 'f')
383 /* The mantissa so far was fff...f Now increment the
384 leading digit. Here it is again possible that we
387 leading
= info
->spec
;
388 else if (tolower (leading
) < 'f')
398 exponent
= -exponent
;
416 /* Now we can compute the exponent string. */
417 expstr
= _itoa_word (exponent
, expbuf
+ sizeof expbuf
, 10, 0);
418 wexpstr
= _itowa_word (exponent
,
419 wexpbuf
+ sizeof wexpbuf
/ sizeof (wchar_t), 10, 0);
421 /* Now we have all information to compute the size. */
422 width
-= ((negative
|| info
->showsign
|| info
->space
)
424 + 2 + 1 + 0 + precision
+ 1 + 1
425 /* 0x h . hhh P ExpoSign. */
426 + ((expbuf
+ sizeof expbuf
) - expstr
));
429 /* Count the decimal point.
430 A special case when the mantissa or the precision is zero and the `#'
431 is not given. In this case we must not print the decimal point. */
432 if (precision
> 0 || info
->alt
)
433 width
-= wide
? 1 : strlen (decimal
);
435 if (!info
->left
&& info
->pad
!= '0' && width
> 0)
440 else if (info
->showsign
)
442 else if (info
->space
)
446 if ('X' - 'A' == 'x' - 'a')
447 outchar (info
->spec
+ ('x' - 'a'));
449 outchar (info
->spec
== 'A' ? 'X' : 'x');
451 if (!info
->left
&& info
->pad
== '0' && width
> 0)
456 if (precision
> 0 || info
->alt
)
458 const wchar_t *wtmp
= &decimalwc
;
459 PRINT (decimal
, wtmp
, wide
? 1 : strlen (decimal
));
464 ssize_t tofill
= precision
- (numend
- numstr
);
465 PRINT (numstr
, wnumstr
, MIN (numend
- numstr
, precision
));
470 if ('P' - 'A' == 'p' - 'a')
471 outchar (info
->spec
+ ('p' - 'a'));
473 outchar (info
->spec
== 'A' ? 'P' : 'p');
475 outchar (expnegative
? '-' : '+');
477 PRINT (expstr
, wexpstr
, (expbuf
+ sizeof expbuf
) - expstr
);
479 if (info
->left
&& info
->pad
!= '0' && width
> 0)
480 PADN (info
->pad
, width
);