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 #pragma weak fdim = __fdim
  31 
  32 /*
  33  * fdim(x,y) returns x - y if x > y, +0 if x <= y, and NaN if x and
  34  * y are unordered.
  35  *
  36  * fdim(x,y) raises overflow or inexact if x > y and x - y overflows
  37  * or is inexact.  It raises invalid if either operand is a signaling
  38  * NaN.  Otherwise, it raises no exceptions.
  39  */
  40 
  41 #include "libm.h"       /* for islessequal macro */
  42 
  43 double
  44 __fdim(double x, double y) {
  45         if (islessequal(x, y)) {
  46                 x = 0.0;
  47                 y = -x;
  48         }
  49         return (x - y);
  50 }