glibc/stdio-common/printf_fphex.c

501 lines
12 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Print floating point number in hexadecimal notation according to ISO C99.
Copyright (C) 1997-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <ieee754.h>
#include <math.h>
#include <printf.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
#include <_itoa.h>
#include <_itowa.h>
#include <locale/localeinfo.h>
#include <stdbool.h>
#include <rounding-mode.h>
/* #define NDEBUG 1*/ /* Undefine this for debugging assertions. */
#include <assert.h>
/* This defines make it possible to use the same code for GNU C library and
the GNU I/O library. */
#include <libioP.h>
#define PUT(f, s, n) _IO_sputn (f, s, n)
#define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
/* We use this file GNU C library and GNU I/O library. So make
names equal. */
#undef putc
#define putc(c, f) (wide \
? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
#define size_t _IO_size_t
#define FILE _IO_FILE
/* Macros for doing the actual output. */
#define outchar(ch) \
do \
{ \
const int outc = (ch); \
if (putc (outc, fp) == EOF) \
return -1; \
++done; \
} while (0)
#define PRINT(ptr, wptr, len) \
do \
{ \
size_t outlen = (len); \
if (wide) \
while (outlen-- > 0) \
outchar (*wptr++); \
else \
while (outlen-- > 0) \
outchar (*ptr++); \
} while (0)
#define PADN(ch, len) \
do \
{ \
if (PAD (fp, ch, len) != len) \
return -1; \
done += len; \
} \
while (0)
#ifndef MIN
# define MIN(a,b) ((a)<(b)?(a):(b))
#endif
int
__printf_fphex (FILE *fp,
const struct printf_info *info,
const void *const *args)
{
/* The floating-point value to output. */
union
{
union ieee754_double dbl;
long double ldbl;
}
fpnum;
/* Locale-dependent representation of decimal point. */
const char *decimal;
wchar_t decimalwc;
/* "NaN" or "Inf" for the special cases. */
const char *special = NULL;
const wchar_t *wspecial = NULL;
/* Buffer for the generated number string for the mantissa. The
maximal size for the mantissa is 128 bits. */
char numbuf[32];
char *numstr;
char *numend;
wchar_t wnumbuf[32];
wchar_t *wnumstr;
wchar_t *wnumend;
int negative;
/* The maximal exponent of two in decimal notation has 5 digits. */
char expbuf[5];
char *expstr;
wchar_t wexpbuf[5];
wchar_t *wexpstr;
int expnegative;
int exponent;
/* Non-zero is mantissa is zero. */
int zero_mantissa;
/* The leading digit before the decimal point. */
char leading;
/* Precision. */
int precision = info->prec;
/* Width. */
int width = info->width;
/* Number of characters written. */
int done = 0;
/* Nonzero if this is output on a wide character stream. */
int wide = info->wide;
/* Figure out the decimal point character. */
if (info->extra == 0)
{
decimal = _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT);
decimalwc = _NL_CURRENT_WORD (LC_NUMERIC, _NL_NUMERIC_DECIMAL_POINT_WC);
}
else
{
decimal = _NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT);
decimalwc = _NL_CURRENT_WORD (LC_MONETARY,
_NL_MONETARY_DECIMAL_POINT_WC);
}
/* The decimal point character must never be zero. */
assert (*decimal != '\0' && decimalwc != L'\0');
/* Fetch the argument value. */
#ifndef __NO_LONG_DOUBLE_MATH
if (info->is_long_double && sizeof (long double) > sizeof (double))
{
fpnum.ldbl = *(const long double *) args[0];
/* Check for special values: not a number or infinity. */
if (isnan (fpnum.ldbl))
{
if (isupper (info->spec))
{
special = "NAN";
wspecial = L"NAN";
}
else
{
special = "nan";
wspecial = L"nan";
}
}
else
{
if (__isinfl (fpnum.ldbl))
{
if (isupper (info->spec))
{
special = "INF";
wspecial = L"INF";
}
else
{
special = "inf";
wspecial = L"inf";
}
}
}
negative = signbit (fpnum.ldbl);
}
else
#endif /* no long double */
{
fpnum.dbl.d = *(const double *) args[0];
/* Check for special values: not a number or infinity. */
if (isnan (fpnum.dbl.d))
{
negative = fpnum.dbl.ieee.negative != 0;
if (isupper (info->spec))
{
special = "NAN";
wspecial = L"NAN";
}
else
{
special = "nan";
wspecial = L"nan";
}
}
else
{
int res = __isinf (fpnum.dbl.d);
if (res)
{
if (isupper (info->spec))
{
special = "INF";
wspecial = L"INF";
}
else
{
special = "inf";
wspecial = L"inf";
}
negative = res < 0;
}
else
negative = signbit (fpnum.dbl.d);
}
}
if (special)
{
int width = info->width;
if (negative || info->showsign || info->space)
--width;
width -= 3;
if (!info->left && width > 0)
PADN (' ', width);
if (negative)
outchar ('-');
else if (info->showsign)
outchar ('+');
else if (info->space)
outchar (' ');
PRINT (special, wspecial, 3);
if (info->left && width > 0)
PADN (' ', width);
return done;
}
if (info->is_long_double == 0 || sizeof (double) == sizeof (long double))
{
/* We have 52 bits of mantissa plus one implicit digit. Since
52 bits are representable without rest using hexadecimal
digits we use only the implicit digits for the number before
the decimal point. */
unsigned long long int num;
num = (((unsigned long long int) fpnum.dbl.ieee.mantissa0) << 32
| fpnum.dbl.ieee.mantissa1);
zero_mantissa = num == 0;
if (sizeof (unsigned long int) > 6)
{
wnumstr = _itowa_word (num, wnumbuf + (sizeof wnumbuf) / sizeof (wchar_t), 16,
info->spec == 'A');
numstr = _itoa_word (num, numbuf + sizeof numbuf, 16,
info->spec == 'A');
}
else
{
wnumstr = _itowa (num, wnumbuf + sizeof wnumbuf / sizeof (wchar_t), 16,
info->spec == 'A');
numstr = _itoa (num, numbuf + sizeof numbuf, 16,
info->spec == 'A');
}
/* Fill with zeroes. */
while (wnumstr > wnumbuf + (sizeof wnumbuf - 52) / sizeof (wchar_t))
{
*--wnumstr = L'0';
*--numstr = '0';
}
leading = fpnum.dbl.ieee.exponent == 0 ? '0' : '1';
exponent = fpnum.dbl.ieee.exponent;
if (exponent == 0)
{
if (zero_mantissa)
expnegative = 0;
else
{
/* This is a denormalized number. */
expnegative = 1;
exponent = IEEE754_DOUBLE_BIAS - 1;
}
}
else if (exponent >= IEEE754_DOUBLE_BIAS)
{
expnegative = 0;
exponent -= IEEE754_DOUBLE_BIAS;
}
else
{
expnegative = 1;
exponent = -(exponent - IEEE754_DOUBLE_BIAS);
}
}
#ifdef PRINT_FPHEX_LONG_DOUBLE
else
PRINT_FPHEX_LONG_DOUBLE;
#endif
/* Look for trailing zeroes. */
if (! zero_mantissa)
{
wnumend = &wnumbuf[sizeof wnumbuf / sizeof wnumbuf[0]];
numend = &numbuf[sizeof numbuf / sizeof numbuf[0]];
while (wnumend[-1] == L'0')
{
--wnumend;
--numend;
}
bool do_round_away = false;
if (precision != -1 && precision < numend - numstr)
{
char last_digit = precision > 0 ? numstr[precision - 1] : leading;
char next_digit = numstr[precision];
int last_digit_value = (last_digit >= 'A' && last_digit <= 'F'
? last_digit - 'A' + 10
: (last_digit >= 'a' && last_digit <= 'f'
? last_digit - 'a' + 10
: last_digit - '0'));
int next_digit_value = (next_digit >= 'A' && next_digit <= 'F'
? next_digit - 'A' + 10
: (next_digit >= 'a' && next_digit <= 'f'
? next_digit - 'a' + 10
: next_digit - '0'));
bool more_bits = ((next_digit_value & 7) != 0
|| precision + 1 < numend - numstr);
int rounding_mode = get_rounding_mode ();
do_round_away = round_away (negative, last_digit_value & 1,
next_digit_value >= 8, more_bits,
rounding_mode);
}
if (precision == -1)
precision = numend - numstr;
else if (do_round_away)
{
/* Round up. */
int cnt = precision;
while (--cnt >= 0)
{
char ch = numstr[cnt];
/* We assume that the digits and the letters are ordered
like in ASCII. This is true for the rest of GNU, too. */
if (ch == '9')
{
wnumstr[cnt] = (wchar_t) info->spec;
numstr[cnt] = info->spec; /* This is tricky,
think about it! */
break;
}
else if (tolower (ch) < 'f')
{
++numstr[cnt];
++wnumstr[cnt];
break;
}
else
{
numstr[cnt] = '0';
wnumstr[cnt] = L'0';
}
}
if (cnt < 0)
{
/* The mantissa so far was fff...f Now increment the
leading digit. Here it is again possible that we
get an overflow. */
if (leading == '9')
leading = info->spec;
else if (tolower (leading) < 'f')
++leading;
else
{
leading = '1';
if (expnegative)
{
exponent -= 4;
if (exponent <= 0)
{
exponent = -exponent;
expnegative = 0;
}
}
else
exponent += 4;
}
}
}
}
else
{
if (precision == -1)
precision = 0;
numend = numstr;
wnumend = wnumstr;
}
/* Now we can compute the exponent string. */
expstr = _itoa_word (exponent, expbuf + sizeof expbuf, 10, 0);
wexpstr = _itowa_word (exponent,
wexpbuf + sizeof wexpbuf / sizeof (wchar_t), 10, 0);
/* Now we have all information to compute the size. */
width -= ((negative || info->showsign || info->space)
/* Sign. */
+ 2 + 1 + 0 + precision + 1 + 1
/* 0x h . hhh P ExpoSign. */
+ ((expbuf + sizeof expbuf) - expstr));
/* Exponent. */
/* Count the decimal point.
A special case when the mantissa or the precision is zero and the `#'
is not given. In this case we must not print the decimal point. */
if (precision > 0 || info->alt)
width -= wide ? 1 : strlen (decimal);
if (!info->left && info->pad != '0' && width > 0)
PADN (' ', width);
if (negative)
outchar ('-');
else if (info->showsign)
outchar ('+');
else if (info->space)
outchar (' ');
outchar ('0');
if ('X' - 'A' == 'x' - 'a')
outchar (info->spec + ('x' - 'a'));
else
outchar (info->spec == 'A' ? 'X' : 'x');
if (!info->left && info->pad == '0' && width > 0)
PADN ('0', width);
outchar (leading);
if (precision > 0 || info->alt)
{
const wchar_t *wtmp = &decimalwc;
PRINT (decimal, wtmp, wide ? 1 : strlen (decimal));
}
if (precision > 0)
{
ssize_t tofill = precision - (numend - numstr);
PRINT (numstr, wnumstr, MIN (numend - numstr, precision));
if (tofill > 0)
PADN ('0', tofill);
}
if ('P' - 'A' == 'p' - 'a')
outchar (info->spec + ('p' - 'a'));
else
outchar (info->spec == 'A' ? 'P' : 'p');
outchar (expnegative ? '-' : '+');
PRINT (expstr, wexpstr, (expbuf + sizeof expbuf) - expstr);
if (info->left && info->pad != '0' && width > 0)
PADN (info->pad, width);
return done;
}