gcc/gcc/realmpfr.c
2021-01-04 10:26:59 +01:00

115 lines
3.1 KiB
C

/* Conversion routines from GCC internal float representation to MPFR.
Copyright (C) 2010-2021 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "realmpfr.h"
#include "stor-layout.h"
/* Convert from REAL_VALUE_TYPE to MPFR. The caller is responsible
for initializing and clearing the MPFR parameter. */
void
mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mpfr_rnd_t rndmode)
{
/* We use a string as an intermediate type. */
char buf[128];
int ret;
/* Take care of Infinity and NaN. */
if (r->cl == rvc_inf)
{
mpfr_set_inf (m, r->sign == 1 ? -1 : 1);
return;
}
if (r->cl == rvc_nan)
{
mpfr_set_nan (m);
return;
}
real_to_hexadecimal (buf, r, sizeof (buf), 0, 1);
/* mpfr_set_str() parses hexadecimal floats from strings in the same
format that GCC will output them. Nothing extra is needed. */
ret = mpfr_set_str (m, buf, 16, rndmode);
gcc_assert (ret == 0);
}
/* Convert from MPFR to REAL_VALUE_TYPE, for a given format FORMAT and
rounding mode RNDMODE. FORMAT is only relevant if M is a NaN. */
void
real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, const real_format *format,
mpfr_rnd_t rndmode)
{
/* We use a string as an intermediate type. */
char buf[128], *rstr;
mpfr_exp_t exp;
/* Take care of Infinity and NaN. */
if (mpfr_inf_p (m))
{
real_inf (r);
if (mpfr_sgn (m) < 0)
*r = real_value_negate (r);
return;
}
if (mpfr_nan_p (m))
{
real_nan (r, "", 1, format);
return;
}
rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode);
/* The additional 12 chars add space for the sprintf below. This
leaves 6 digits for the exponent which is supposedly enough. */
gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12);
/* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp,
mpfr_get_str returns the exponent for mantissa * 16**exp, adjust
for that. */
exp *= 4;
if (rstr[0] == '-')
sprintf (buf, "-0x.%sp%d", &rstr[1], (int) exp);
else
sprintf (buf, "0x.%sp%d", rstr, (int) exp);
mpfr_free_str (rstr);
real_from_string (r, buf);
}
/* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding
mode RNDMODE. TYPE is only relevant if M is a NaN. */
void
real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type,
mpfr_rnd_t rndmode)
{
real_from_mpfr (r, m, type ? REAL_MODE_FORMAT (TYPE_MODE (type)) : NULL,
rndmode);
}