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/* Generate table of tests in tst-strtod-round.c from
tst-strtod-round-data.
Copyright (C) 2012-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
/* Compile this program as:
gcc -std=gnu11 -O2 -Wall -Wextra gen-tst-strtod-round.c -lmpfr \
-o gen-tst-strtod-round
(use of current MPFR version recommended) and run it as:
gen-tst-strtod-round tst-strtod-round-data tst-strtod-round-data.h
The output file will be generated as tst-strtod-round-data.h
*/
#define _GNU_SOURCE
#include <assert.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mpfr.h>
/* Work around incorrect ternary value from mpfr_strtofr
<https://sympa.inria.fr/sympa/arc/mpfr/2012-08/msg00005.html>. */
#define WORKAROUND
static int
string_to_fp (mpfr_t f, const char *s, mpfr_rnd_t rnd)
{
mpfr_clear_overflow ();
mpfr_clear_underflow ();
#ifdef WORKAROUND
mpfr_t f2;
mpfr_init2 (f2, 100000);
int r0 = mpfr_strtofr (f2, s, NULL, 0, rnd);
int r = mpfr_set (f, f2, rnd);
r |= mpfr_subnormalize (f, r, rnd);
mpfr_clear (f2);
r |= r0;
#else
int r = mpfr_strtofr (f, s, NULL, 0, rnd);
r |= mpfr_subnormalize (f, r, rnd);
#endif
if (r == 0)
/* The MPFR underflow flag is set for exact subnormal results,
which is not wanted here. */
mpfr_clear_underflow ();
return r;
}
void
print_fp (FILE *fout, mpfr_t f, const char *suffix)
{
if (mpfr_inf_p (f))
mpfr_fprintf (fout, "\t%sINF%s", mpfr_signbit (f) ? "-" : "", suffix);
else
mpfr_fprintf (fout, "\t%Ra%s", f, suffix);
}
static const char *
suffix_to_print (bool overflow, bool underflow, bool underflow_before_rounding,
bool with_comma)
{
if (overflow)
return with_comma ? ", true, false,\n" : ", true, false";
if (underflow)
return with_comma ? ", false, true,\n" : ", false, true";
if (underflow_before_rounding)
return (with_comma
? ", false, !TININESS_AFTER_ROUNDING,\n"
: ", false, !TININESS_AFTER_ROUNDING");
return with_comma ? ", false, false,\n" : ", false, false";
}
static void
round_str (FILE *fout, const char *s, int prec, int emin, int emax,
bool ibm_ld)
{
mpfr_t max_value;
mpfr_t f;
mpfr_set_default_prec (prec);
mpfr_set_emin (emin);
mpfr_set_emax (emax);
mpfr_init (f);
string_to_fp (f, s, MPFR_RNDZ);
bool underflow_before_rounding = mpfr_underflow_p () != 0;
int r = string_to_fp (f, s, MPFR_RNDD);
bool overflow = mpfr_overflow_p () != 0;
bool underflow = mpfr_underflow_p () != 0;
if (ibm_ld)
{
assert (prec == 106 && emin == -1073 && emax == 1024);
/* The maximum value in IBM long double has discontiguous
mantissa bits. */
mpfr_init2 (max_value, 107);
mpfr_set_str (max_value, "0x1.fffffffffffff7ffffffffffffcp+1023", 0,
MPFR_RNDN);
if (mpfr_cmpabs (f, max_value) > 0)
{
r = 1;
overflow = true;
}
}
mpfr_fprintf (fout, "\t%s,\n", r ? "false" : "true");
print_fp (fout, f,
suffix_to_print (overflow, underflow, underflow_before_rounding,
true));
string_to_fp (f, s, MPFR_RNDN);
overflow = (mpfr_overflow_p () != 0
|| (ibm_ld && mpfr_cmpabs (f, max_value) > 0));
print_fp (fout, f,
suffix_to_print (overflow, underflow, underflow_before_rounding,
true));
string_to_fp (f, s, MPFR_RNDZ);
overflow = (mpfr_overflow_p () != 0
|| (ibm_ld && mpfr_cmpabs (f, max_value) > 0));
print_fp (fout, f,
suffix_to_print (overflow, underflow, underflow_before_rounding,
true));
string_to_fp (f, s, MPFR_RNDU);
overflow = (mpfr_overflow_p () != 0
|| (ibm_ld && mpfr_cmpabs (f, max_value) > 0));
print_fp (fout, f,
suffix_to_print (overflow, underflow, underflow_before_rounding,
false));
mpfr_clear (f);
if (ibm_ld)
mpfr_clear (max_value);
}
static void
round_for_all (FILE *fout, const char *s)
{
static const struct fmt {
int prec;
int emin;
int emax;
bool ibm_ld;
} formats[] = {
{ 24, -148, 128, false },
{ 53, -1073, 1024, false },
/* This is the Intel extended float format. */
{ 64, -16444, 16384, false },
/* This is the Motorola extended float format. */
{ 64, -16445, 16384, false },
{ 106, -1073, 1024, true },
{ 113, -16493, 16384, false },
};
mpfr_fprintf (fout, " TEST (\"");
const char *p;
for (p = s; *p; p++)
{
fputc (*p, fout);
if ((p - s) % 60 == 59 && p[1])
mpfr_fprintf (fout, "\"\n\t\"");
}
mpfr_fprintf (fout, "\",\n");
int i;
int n_formats = sizeof (formats) / sizeof (formats[0]);
for (i = 0; i < n_formats; i++)
{
round_str (fout, s, formats[i].prec, formats[i].emin,
formats[i].emax, formats[i].ibm_ld);
if (i < n_formats - 1)
mpfr_fprintf (fout, ",\n");
}
mpfr_fprintf (fout, "),\n");
}
int
main (int argc, char **argv)
{
char *p = NULL;
size_t len;
ssize_t nbytes;
FILE *fin, *fout;
char *fin_name, *fout_name;
if (argc < 3)
{
fprintf (stderr, "Usage: %s <input> <output>\n", basename (argv[0]));
return EXIT_FAILURE;
}
fin_name = argv[1];
fout_name = argv[2];
fin = fopen (fin_name, "r");
if (fin == NULL)
{
perror ("Could not open input for reading");
return EXIT_FAILURE;
}
fout = fopen (fout_name, "w");
if (fout == NULL)
{
perror ("Could not open output for writing");
return EXIT_FAILURE;
}
fprintf (fout, "/* This file was generated by %s from %s. */\n",
__FILE__, fin_name);
fputs ("static const struct test tests[] = {\n", fout);
while ((nbytes = getline (&p, &len, fin)) != -1)
{
if (p[nbytes - 1] == '\n')
p[nbytes - 1] = 0;
round_for_all (fout, p);
free (p);
p = NULL;
}
fputs ("};\n", fout);
return EXIT_SUCCESS;
}
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