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