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/* Truncate argument to nearest integral value not larger than the argument.
Copyright (C) 1997-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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/>. */
#define NO_MATH_REDIRECT
#include <math.h>
#include <math_private.h>
#include <libm-alias-double.h>
#include <math-use-builtins.h>
double
__trunc (double x)
{
#if USE_TRUNC_BUILTIN
return __builtin_trunc (x);
#else
/* Use generic implementation. */
int64_t i0, j0;
int64_t sx;
EXTRACT_WORDS64 (i0, x);
sx = i0 & UINT64_C (0x8000000000000000);
j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
if (j0 < 52)
{
if (j0 < 0)
/* The magnitude of the number is < 1 so the result is +-0. */
INSERT_WORDS64 (x, sx);
else
INSERT_WORDS64 (x, sx | (i0 & ~(UINT64_C (0x000fffffffffffff) >> j0)));
}
else
{
if (j0 == 0x400)
/* x is inf or NaN. */
return x + x;
}
return x;
#endif /* ! USE_TRUNC_BUILTIN */
}
#ifndef __trunc
libm_alias_double (__trunc, trunc)
#endif
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