/* Test of <float.h> substitute.
Copyright (C) 2011-2017 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 <http://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2011. */
#include <config.h>
#include <float.h>
#include "fpucw.h"
#include "macros.h"
/* Check that FLT_RADIX is a constant expression. */
int a[] = { FLT_RADIX };
#if FLT_RADIX == 2
/* Return 2^n. */
static float
pow2f (int n)
{
int k = n;
volatile float x = 1;
volatile float y = 2;
/* Invariant: 2^n == x * y^k. */
if (k < 0)
{
y = 0.5f;
k = - k;
}
while (k > 0)
{
if (k != 2 * (k / 2))
{
x = x * y;
k = k - 1;
}
if (k == 0)
break;
y = y * y;
k = k / 2;
}
/* Now k == 0, hence x == 2^n. */
return x;
}
/* Return 2^n. */
static double
pow2d (int n)
{
int k = n;
volatile double x = 1;
volatile double y = 2;
/* Invariant: 2^n == x * y^k. */
if (k < 0)
{
y = 0.5;
k = - k;
}
while (k > 0)
{
if (k != 2 * (k / 2))
{
x = x * y;
k = k - 1;
}
if (k == 0)
break;
y = y * y;
k = k / 2;
}
/* Now k == 0, hence x == 2^n. */
return x;
}
/* Return 2^n. */
static long double
pow2l (int n)
{
int k = n;
volatile long double x = 1;
volatile long double y = 2;
/* Invariant: 2^n == x * y^k. */
if (k < 0)
{
y = 0.5L;
k = - k;
}
while (k > 0)
{
if (k != 2 * (k / 2))
{
x = x * y;
k = k - 1;
}
if (k == 0)
break;
y = y * y;
k = k / 2;
}
/* Now k == 0, hence x == 2^n. */
return x;
}
/* ----------------------- Check macros for 'float' ----------------------- */
/* Check that the FLT_* macros expand to constant expressions. */
int fb[] =
{
FLT_MANT_DIG, FLT_MIN_EXP, FLT_MAX_EXP,
FLT_DIG, FLT_MIN_10_EXP, FLT_MAX_10_EXP
};
float fc[] = { FLT_EPSILON, FLT_MIN, FLT_MAX };
static void
test_float (void)
{
/* Check that the value of FLT_MIN_EXP is well parenthesized. */
ASSERT ((FLT_MIN_EXP % 101111) == (FLT_MIN_EXP) % 101111);
/* Check that the value of DBL_MIN_10_EXP is well parenthesized. */
ASSERT ((FLT_MIN_10_EXP % 101111) == (FLT_MIN_10_EXP) % 101111);
/* Check that 'float' is as specified in IEEE 754. */
ASSERT (FLT_MANT_DIG == 24);
ASSERT (FLT_MIN_EXP == -125);
ASSERT (FLT_MAX_EXP == 128);
/* Check the value of FLT_MIN_10_EXP. */
ASSERT (FLT_MIN_10_EXP == - (int) (- (FLT_MIN_EXP - 1) * 0.30103));
/* Check the value of FLT_DIG. */
ASSERT (FLT_DIG == (int) ((FLT_MANT_DIG - 1) * 0.30103));
/* Check the value of FLT_MIN_10_EXP. */
ASSERT (FLT_MIN_10_EXP == - (int) (- (FLT_MIN_EXP - 1) * 0.30103));
/* Check the value of FLT_MAX_10_EXP. */
ASSERT (FLT_MAX_10_EXP == (int) (FLT_MAX_EXP * 0.30103));
/* Check the value of FLT_MAX. */
{
volatile float m = FLT_MAX;
int n;
ASSERT (m + m > m);
for (n = 0; n <= 2 * FLT_MANT_DIG; n++)
{
volatile float pow2_n = pow2f (n); /* 2^n */
volatile float x = m + (m / pow2_n);
if (x > m)
ASSERT (x + x == x);
else
ASSERT (!(x + x == x));
}
}
/* Check the value of FLT_MIN. */
{
volatile float m = FLT_MIN;
volatile float x = pow2f (FLT_MIN_EXP - 1);
ASSERT (m == x);
}
/* Check the value of FLT_EPSILON. */
{
volatile float e = FLT_EPSILON;
volatile float me;
int n;
me = 1.0f + e;
ASSERT (me > 1.0f);
ASSERT (me - 1.0f == e);
for (n = 0; n <= 2 * FLT_MANT_DIG; n++)
{
volatile float half_n = pow2f (- n); /* 2^-n */
volatile float x = me - half_n;
if (x < me)
ASSERT (x <= 1.0f);
}
}
}
/* ----------------------- Check macros for 'double' ----------------------- */
/* Check that the DBL_* macros expand to constant expressions. */
int db[] =
{
DBL_MANT_DIG, DBL_MIN_EXP, DBL_MAX_EXP,
DBL_DIG, DBL_MIN_10_EXP, DBL_MAX_10_EXP
};
double dc[] = { DBL_EPSILON, DBL_MIN, DBL_MAX };
static void
test_double (void)
{
/* Check that the value of DBL_MIN_EXP is well parenthesized. */
ASSERT ((DBL_MIN_EXP % 101111) == (DBL_MIN_EXP) % 101111);
/* Check that the value of DBL_MIN_10_EXP is well parenthesized. */
ASSERT ((DBL_MIN_10_EXP % 101111) == (DBL_MIN_10_EXP) % 101111);
/* Check that 'double' is as specified in IEEE 754. */
ASSERT (DBL_MANT_DIG == 53);
ASSERT (DBL_MIN_EXP == -1021);
ASSERT (DBL_MAX_EXP == 1024);
/* Check the value of DBL_MIN_10_EXP. */
ASSERT (DBL_MIN_10_EXP == - (int) (- (DBL_MIN_EXP - 1) * 0.30103));
/* Check the value of DBL_DIG. */
ASSERT (DBL_DIG == (int) ((DBL_MANT_DIG - 1) * 0.30103));
/* Check the value of DBL_MIN_10_EXP. */
ASSERT (DBL_MIN_10_EXP == - (int) (- (DBL_MIN_EXP - 1) * 0.30103));
/* Check the value of DBL_MAX_10_EXP. */
ASSERT (DBL_MAX_10_EXP == (int) (DBL_MAX_EXP * 0.30103));
/* Check the value of DBL_MAX. */
{
volatile double m = DBL_MAX;
int n;
ASSERT (m + m > m);
for (n = 0; n <= 2 * DBL_MANT_DIG; n++)
{
volatile double pow2_n = pow2d (n); /* 2^n */
volatile double x = m + (m / pow2_n);
if (x > m)
ASSERT (x + x == x);
else
ASSERT (!(x + x == x));
}
}
/* Check the value of DBL_MIN. */
{
volatile double m = DBL_MIN;
volatile double x = pow2d (DBL_MIN_EXP - 1);
ASSERT (m == x);
}
/* Check the value of DBL_EPSILON. */
{
volatile double e = DBL_EPSILON;
volatile double me;
int n;
me = 1.0 + e;
ASSERT (me > 1.0);
ASSERT (me - 1.0 == e);
for (n = 0; n <= 2 * DBL_MANT_DIG; n++)
{
volatile double half_n = pow2d (- n); /* 2^-n */
volatile double x = me - half_n;
if (x < me)
ASSERT (x <= 1.0);
}
}
}
/* -------------------- Check macros for 'long double' -------------------- */
/* Check that the LDBL_* macros expand to constant expressions. */
int lb[] =
{
LDBL_MANT_DIG, LDBL_MIN_EXP, LDBL_MAX_EXP,
LDBL_DIG, LDBL_MIN_10_EXP, LDBL_MAX_10_EXP
};
long double lc1 = LDBL_EPSILON;
long double lc2 = LDBL_MIN;
#if 0 /* LDBL_MAX is not a constant expression on some platforms. */
long double lc3 = LDBL_MAX;
#endif
static void
test_long_double (void)
{
/* Check that the value of LDBL_MIN_EXP is well parenthesized. */
ASSERT ((LDBL_MIN_EXP % 101111) == (LDBL_MIN_EXP) % 101111);
/* Check that the value of LDBL_MIN_10_EXP is well parenthesized. */
ASSERT ((LDBL_MIN_10_EXP % 101111) == (LDBL_MIN_10_EXP) % 101111);
/* Check that 'long double' is at least as wide as 'double'. */
ASSERT (LDBL_MANT_DIG >= DBL_MANT_DIG);
ASSERT (LDBL_MIN_EXP - LDBL_MANT_DIG <= DBL_MIN_EXP - DBL_MANT_DIG);
ASSERT (LDBL_MAX_EXP >= DBL_MAX_EXP);
/* Check the value of LDBL_DIG. */
ASSERT (LDBL_DIG == (int)((LDBL_MANT_DIG - 1) * 0.30103));
/* Check the value of LDBL_MIN_10_EXP. */
ASSERT (LDBL_MIN_10_EXP == - (int) (- (LDBL_MIN_EXP - 1) * 0.30103));
/* Check the value of LDBL_MAX_10_EXP. */
ASSERT (LDBL_MAX_10_EXP == (int) (LDBL_MAX_EXP * 0.30103));
/* Check the value of LDBL_MAX. */
{
volatile long double m = LDBL_MAX;
int n;
ASSERT (m + m > m);
for (n = 0; n <= 2 * LDBL_MANT_DIG; n++)
{
volatile long double pow2_n = pow2l (n); /* 2^n */
volatile long double x = m + (m / pow2_n);
if (x > m)
ASSERT (x + x == x);
else
ASSERT (!(x + x == x));
}
}
/* Check the value of LDBL_MIN. */
{
volatile long double m = LDBL_MIN;
volatile long double x = pow2l (LDBL_MIN_EXP - 1);
ASSERT (m == x);
}
/* Check the value of LDBL_EPSILON. */
{
volatile long double e = LDBL_EPSILON;
volatile long double me;
int n;
me = 1.0L + e;
ASSERT (me > 1.0L);
ASSERT (me - 1.0L == e);
for (n = 0; n <= 2 * LDBL_MANT_DIG; n++)
{
volatile long double half_n = pow2l (- n); /* 2^-n */
volatile long double x = me - half_n;
if (x < me)
ASSERT (x <= 1.0L);
}
}
}
int
main ()
{
test_float ();
test_double ();
{
DECL_LONG_DOUBLE_ROUNDING
BEGIN_LONG_DOUBLE_ROUNDING ();
test_long_double ();
END_LONG_DOUBLE_ROUNDING ();
}
return 0;
}
#else
int
main ()
{
fprintf (stderr, "Skipping test: FLT_RADIX is not 2.\n");
return 77;
}
#endif