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- /* Truncate argument to nearest integral value not larger than the argument.
- Copyright (C) 1997, 1998 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
- <http://www.gnu.org/licenses/>. */
- #include <math.h>
- #include "math_private.h"
- double
- trunc (double x)
- {
- int32_t i0, _j0;
- u_int32_t i1;
- int sx;
- EXTRACT_WORDS (i0, i1, x);
- sx = i0 & 0x80000000;
- _j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
- if (_j0 < 20)
- {
- if (_j0 < 0)
- /* The magnitude of the number is < 1 so the result is +-0. */
- INSERT_WORDS (x, sx, 0);
- else
- INSERT_WORDS (x, sx | (i0 & ~(0x000fffff >> _j0)), 0);
- }
- else if (_j0 > 51)
- {
- if (_j0 == 0x400)
- /* x is inf or NaN. */
- return x + x;
- }
- else
- {
- INSERT_WORDS (x, i0, i1 & ~(0xffffffffu >> (_j0 - 20)));
- }
- return x;
- }
- libm_hidden_def(trunc)
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