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 nan = __nan
  32 
  33 /*
  34  *  nan(c) returns a NaN.  This implementation ignores c.
  35  */
  36 
  37 #include "libm.h"
  38 #include <sys/isa_defs.h>
  39 
  40 #if defined(__sparc)
  41 static const union {
  42         unsigned i[2];
  43         double d;
  44 } __nan_union = { 0x7fffffff, 0xffffffff };
  45 #elif defined(__i386) || defined(__amd64)
  46 static const union {
  47         unsigned i[2];
  48         double d;
  49 } __nan_union = { 0xffffffff, 0x7fffffff };
  50 #else
  51 #error Unknown architecture
  52 #endif
  53 
  54 /* ARGSUSED0 */
  55 double
  56 __nan(const char *c)
  57 {
  58         return (__nan_union.d);
  59 }