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 nan = __nan
  31 
  32 /*
  33  *  nan(c) returns a NaN.  This implementation ignores c.
  34  */
  35 
  36 #include "libm.h"
  37 #include <sys/isa_defs.h>
  38 
  39 #if defined(__sparc)
  40 
  41 static const union {
  42         unsigned i[2];
  43         double d;
  44 } __nan_union = { 0x7fffffff, 0xffffffff };
  45 
  46 #elif defined(__i386) || defined(__amd64)
  47 
  48 static const union {
  49         unsigned i[2];
  50         double d;
  51 } __nan_union = { 0xffffffff, 0x7fffffff };
  52 
  53 #else
  54 #error Unknown architecture
  55 #endif
  56 
  57 /* ARGSUSED0 */
  58 double
  59 __nan(const char *c) {
  60         return (__nan_union.d);
  61 }