usr/src/lib/libm/common/Q/floorl.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  24  */
  25 /*
  26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  27  * Use is subject to license terms.
  28  */
  29
  30 /*
  31  * ceill(x)     return the biggest integral value below x
  32  * floorl(x)    return the least integral value above x
  33  *
  34  * NOTE: aintl(x), anintl(x), ceill(x), floorl(x), and rintl(x) return result
  35  * with the same sign as x's,  including 0.0.
  36  */
  37
  38 #pragma weak __ceill = ceill
  39 #pragma weak __floorl = floorl
  40
  41 #include "libm.h"
  42 #include "longdouble.h"
  43
  44 static const long double qone = 1.0L;
  45
  46 long double
  47 ceill(long double x) {
  48         long double t;
  49
  50         if (!finitel(x))
  51                 return (x + x);
  52         t = rintl(x);
  53         if (t >= x)                     /* already ceil(x) */
  54                 return (t);
  55         else                            /* t < x case: return t+1  */
  56                 return (copysignl(t + qone, x));
  57 }
  58
  59 long double
  60 floorl(long double x) {
  61         long double t;
  62
  63         if (!finitel(x))
  64                 return (x + x);
  65         t = rintl(x);
  66         if (t <= x)
  67                 return (t);             /* already floor(x) */
  68         else                            /* x < t case: return t-1  */
  69             return (copysignl(t - qone, x));
  70 }