Retro68/gcc/libquadmath/math/truncq.c
Wolfgang Thaller 6fbf4226da gcc-9.1
2019-06-20 20:10:10 +02:00

55 lines
1.6 KiB
C

/* Truncate argument to nearest integral value not larger than the argument.
Copyright (C) 1997-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
Jakub Jelinek <jj@ultra.linux.cz>, 1999.
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
<http://www.gnu.org/licenses/>. */
#define NO_MATH_REDIRECT
#include "quadmath-imp.h"
__float128
truncq (__float128 x)
{
int32_t j0;
uint64_t i0, i1, sx;
GET_FLT128_WORDS64 (i0, i1, x);
sx = i0 & 0x8000000000000000ULL;
j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
if (j0 < 48)
{
if (j0 < 0)
/* The magnitude of the number is < 1 so the result is +-0. */
SET_FLT128_WORDS64 (x, sx, 0);
else
SET_FLT128_WORDS64 (x, i0 & ~(0x0000ffffffffffffLL >> j0), 0);
}
else if (j0 > 111)
{
if (j0 == 0x4000)
/* x is inf or NaN. */
return x + x;
}
else
{
SET_FLT128_WORDS64 (x, i0, i1 & ~(0xffffffffffffffffULL >> (j0 - 48)));
}
return x;
}