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/* snarfed from BSD common_source/floor.c:
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)floor.c 5.7 (Berkeley) 10/9/90";
#endif /* not lint */
#include "mathimpl.h"
vc(L, 4503599627370496.0E0 ,0000,5c00,0000,0000, 55, 1.0) /* 2**55 */
ic(L, 4503599627370496.0E0, 52, 1.0) /* 2**52 */
#ifdef vccast
#define L vccast(L)
#endif
/*
* floor(x) := the largest integer no larger than x;
* ceil(x) := -floor(-x), for all real x.
*
* Note: Inexact will be signaled if x is not an integer, as is
* customary for IEEE 754. No other signal can be emitted.
*/
double
floor(x)
double x;
{
double y;
if (
#if !defined(vax)&&!defined(tahoe)
x != x || /* NaN */
#endif /* !defined(vax)&&!defined(tahoe) */
x >= L) /* already an even integer */
return x;
else if (x < (double)0)
return -ceil(-x);
else { /* now 0 <= x < L */
y = L+x; /* destructive store must be forced */
y -= L; /* an integer, and |x-y| < 1 */
return x < y ? y-(double)1 : y;
}
}
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