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/* Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Geoffrey Keating <Geoff.Keating@anu.edu.au>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* This is a generic program for comparing two precisions of a one-input
mathematical function. It is amazingly good at detecting when GCC
folds constants improperly. */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <math.h>
#include <ieee754.h>
#include <fenv.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define TSMALL float
#define RSMALL(rfun) ({ unsigned rnum = (rfun); *(float *) &rnum; })
#define TBIG double
#define XDIFF (24)
#define REDUCE(x) \
({ union ieee754_float u = { x }; u.ieee.exponent = 0x80; x = u.f; })
#define ABS(x) fabs(x)
#define string_0(x) #x
#define string_1(x) string_0(x)
#define TBIG_NAME string_1(TBIG)
#define TSMALL_NAME string_1(TSMALL)
#define R_NEAREST 1
#define R_ZERO 2
#define R_UP 4
#define R_DOWN 8
#define R_ALL (R_NEAREST|R_ZERO|R_UP|R_DOWN)
static fenv_t rmodes[4];
static const char * const rmnames[4] =
{ "near","zero","+Inf","-Inf" };
static int quiet = 0;
#ifdef FE_ALL_INVALID
static const int invalid_exceptions = (FE_ALL_INVALID
| FE_INVALID | FE_DIVBYZERO);
#else
static const int invalid_exceptions = (FE_INVALID | FE_DIVBYZERO);
#endif
static int
checkit (char *fname,
TSMALL (*fsmall) (TSMALL), TBIG (*fbig) (TBIG),
unsigned smalltries, unsigned largetries)
{
unsigned int i, nerrors = 0, nwarn;
int tryone (TSMALL fval)
{
int rmode;
int excepts, exceptsb;
TSMALL fres;
TBIG fvalb, fresb, diff;
char warn;
fvalb = (TBIG) fval;
for (rmode = 0; rmode < 4; ++rmode)
{
fesetenv (rmodes + rmode);
fres = fsmall (fval);
excepts = fetestexcept (invalid_exceptions);
fesetenv (rmodes + rmode);
fresb = fbig (fvalb);
exceptsb = fetestexcept (invalid_exceptions);
if (excepts != exceptsb)
{
unsigned char *fvp = (unsigned char *) &fval;
size_t j;
printf ("%s(", fname);
for (j = 0; j < sizeof (TSMALL); j++)
printf ("%02x", fvp[j]);
printf ("),%s: exceptions %s: %08x, %s: %08x\n",
rmnames[rmode],
TBIG_NAME, exceptsb, TSMALL_NAME, excepts);
if (++nerrors > 10)
return 1;
}
diff = ABS (fres - (TSMALL) fresb);
if (fres == (TSMALL) fresb
|| isnan (fres) && isnan (fresb)
|| logb (fresb) - logb (diff) < XDIFF - 1)
continue;
if (logb (fresb) - logb (diff) < XDIFF)
{
if (++nwarn > 10 || quiet)
continue;
warn = 'w';
}
else
{
if (++nerrors > 10)
return 1;
warn = 'e';
}
{
TSMALL fresbs = (TSMALL) fresb;
unsigned char *fvp = (unsigned char *) &fval;
unsigned char *frp = (unsigned char *) &fres;
unsigned char *frpb = (unsigned char *) &fresb;
unsigned char *frpbs = (unsigned char *) &fresbs;
size_t j;
printf ("%s(",fname);
for (j = 0; j < sizeof (TSMALL); ++j)
printf ("%02x", fvp[j]);
printf ("),%s: %s ", rmnames[rmode], TBIG_NAME);
for (j = 0; j < sizeof (TBIG); ++j)
printf ("%02x", frpb[j]);
printf (" (");
for (j = 0; j < sizeof (TSMALL); ++j)
printf ("%02x", frpbs[j]);
printf ("), %s ", TSMALL_NAME);
for (j = 0; j < sizeof (TSMALL); ++j)
printf ("%02x", frp[j]);
printf (" %c\n", warn);
}
}
return 0;
}
nwarn = 0;
for (i = 0; i < smalltries; i++)
{
TSMALL fval;
fval = RSMALL (rand () ^ rand () << 16);
REDUCE (fval);
if (tryone (fval))
break;
}
printf ("%s-small: %d errors, %d (%0.2f%%) inaccuracies\n",
fname, nerrors, nwarn,
nwarn * 0.25 / ((double) smalltries));
nwarn = 0;
for (i = 0; i < largetries; ++i)
{
TSMALL fval;
fval = RSMALL (rand () ^ rand () << 16);
if (tryone (fval))
break;
}
printf ("%s-large: %d errors, %d (%0.2f%%) inaccuracies\n",
fname, nerrors, nwarn,
nwarn * 0.25 / ((double) largetries));
return nerrors == 0;
}
int
main (void)
{
int r;
_LIB_VERSION = _IEEE_;
/* Set up environments for rounding modes. */
fesetenv (FE_DFL_ENV);
fesetround (FE_TONEAREST);
fegetenv (rmodes + 0);
fesetround (FE_TOWARDSZERO);
fegetenv (rmodes + 1);
fesetround (FE_UPWARD);
fegetenv (rmodes + 2);
fesetround (FE_DOWNWARD);
fegetenv (rmodes + 3);
/* Seed the RNG. */
srand (time (0));
/* Do it. */
r = checkit ("exp2", exp2f, exp2, 1 << 20, 1 << 15);
r &= checkit ("exp", expf, exp, 1 << 20, 1 << 15);
return r ? 0 : 1;
}
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