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/*
Copyright (C) 2014 Fredrik Johansson
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "test_helpers.h"
#include "double_extras.h"
#include "mpfr.h"
#include "mag.h"
/* Defined in t-d_log_lower_bound.c, t-d_log_upper_bound.c, t-set_d_2exp_fmpz.c
* and t-set_d.c */
#ifndef d_randtest2
#define d_randtest2 d_randtest2
/* XXX: d_randtest is not good enough */
#define EXP_MINUS_32 2.3283064365386962891e-10
#define EXP_MINUS_64 5.42101086242752217e-20
static double
d_randtest2(flint_rand_t state)
{
ulong m1, m2;
double t;
if (FLINT_BITS == 64)
{
m1 = n_randtest(state) | (UWORD(1) << (FLINT_BITS - 1));
t = ((double) m1) * EXP_MINUS_64;
}
else
{
m1 = n_randtest(state) | (UWORD(1) << (FLINT_BITS - 1));
m2 = n_randtest(state);
t = ((double) m1) * EXP_MINUS_32 +
((double) m2) * EXP_MINUS_64;
}
return t;
}
#endif
TEST_FUNCTION_START(mag_d_log_lower_bound, state)
{
slong iter;
for (iter = 0; iter < 100000 * 0.1 * flint_test_multiplier(); iter++)
{
mpfr_t t;
double x, y, z;
mpfr_init2(t, 53);
x = d_randtest2(state);
x = ldexp(x, 100 - n_randint(state, 200));
switch (n_randint(state, 10))
{
case 0:
x = 1.0 + x;
break;
case 1:
x = 1.0 - x;
break;
case 2:
x = D_INF;
break;
case 3:
x = 0.0;
break;
case 4:
x = D_NAN;
break;
default:
break;
}
y = mag_d_log_lower_bound(x);
mpfr_set_d(t, x, MPFR_RNDD);
mpfr_log(t, t, MPFR_RNDD);
z = mpfr_get_d(t, MPFR_RNDD);
if (y > z || fabs(y-z) > 0.000001 * fabs(z))
{
flint_printf("FAIL\n");
flint_printf("x = %.20g\n", x);
flint_printf("y = %.20g\n", y);
flint_printf("z = %.20g\n", z);
flint_abort();
}
mpfr_clear(t);
}
TEST_FUNCTION_END(state);
}