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 /*
  27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 
  31 #pragma weak fdim = __fdim
  32 
  33 /*
  34  * fdim(x,y) returns x - y if x > y, +0 if x <= y, and NaN if x and
  35  * y are unordered.
  36  *
  37  * fdim(x,y) raises overflow or inexact if x > y and x - y overflows
  38  * or is inexact.  It raises invalid if either operand is a signaling
  39  * NaN.  Otherwise, it raises no exceptions.
  40  */
  41 
  42 #include "libm.h"                       /* for islessequal macro */
  43 
  44 double
  45 __fdim(double x, double y)
  46 {
  47         if (islessequal(x, y)) {
  48                 x = 0.0;
  49                 y = -x;
  50         }
  51 
  52         return (x - y);
  53 }