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/* Test of rounding to nearest, breaking ties away from zero.
Copyright (C) 2007-2019 Free Software Foundation, Inc.
This program 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 of the License, or
(at your option) any later version.
This program 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 this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Ben Pfaff <blp@gnu.org>, 2007.
Heavily based on code by Bruno Haible. */
/* When this test fails on some platform, build it together with the gnulib
module 'fprintf-posix' for optimal debugging output. */
/* Get the two reference implementations of round under the names
round_reference1 and round_reference2.
round.c will #include <config.h> for us. */
#define FLOOR_BASED_ROUND round_reference1
#define FLOOR_FREE_ROUND round_reference2
#include "round.c"
#include <math.h>
#include <float.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "verify.h"
#ifdef USE_LONG_DOUBLE
# error Long double not supported.
#elif ! defined USE_FLOAT
# include "isnand-nolibm.h"
# define ISNAN isnand
# define FUNCTION "round"
# define DOUBLE_UINT uint64_t
# define DOUBLE_BITS 64
# define NUM_HIGHBITS 13
# define NUM_LOWBITS 4
#else /* defined USE_FLOAT */
# include "isnanf-nolibm.h"
# define ISNAN isnanf
# define FUNCTION "roundf"
# define DOUBLE_UINT uint32_t
# define DOUBLE_BITS 32
# define NUM_HIGHBITS 12
# define NUM_LOWBITS 4
#endif
/* Test for equality. */
static bool
equal (const char *message, DOUBLE x, DOUBLE y0, DOUBLE y1)
{
if (ISNAN (y0) ? ISNAN (y1) : y0 == y1)
return true;
else
{
#if GNULIB_TEST_FPRINTF_POSIX
fprintf (stderr, "%s: "FUNCTION"(%g(%a)) = %g(%a) or %g(%a)?\n",
message, x, x, y0, y0, y1, y1);
#endif
return false;
}
}
/* Test the function for a given argument. */
static bool
check (DOUBLE x)
{
DOUBLE ref1 = round_reference1 (x);
DOUBLE ref2 = round_reference2 (x);
DOUBLE result = ROUND (x);
/* If the reference implementations disagree, bail out immediately. */
if (!equal ("reference implementations disagree", x, ref1, ref2))
exit (EXIT_FAILURE);
/* If the actual implementation is wrong, return an error code. */
return equal ("bad round implementation", x, ref1, result);
}
int
main (void)
{
DOUBLE_UINT highbits, lowbits;
int error = 0;
for (highbits = 0; highbits < (1 << NUM_HIGHBITS); highbits++)
for (lowbits = 0; lowbits < (1 << NUM_LOWBITS); lowbits++)
{
/* Combine highbits and lowbits into a floating-point number,
sign-extending the lowbits to DOUBLE_BITS-NUM_HIGHBITS bits. */
union { DOUBLE f; DOUBLE_UINT i; } janus;
verify (sizeof janus.f == sizeof janus.i);
janus.i = lowbits | (highbits << (DOUBLE_BITS - NUM_HIGHBITS));
if (lowbits >> (NUM_LOWBITS - 1))
janus.i |= ((DOUBLE_UINT) -1
>> (NUM_LOWBITS + NUM_HIGHBITS)
<< NUM_LOWBITS);
if (!check (janus.f))
error = true;
}
return (error ? 1 : 0);
}
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