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erand48.c revision 1.8
      1  1.8    lukem /*	$NetBSD: erand48.c,v 1.8 2005/06/12 05:21:28 lukem Exp $	*/
      2  1.4    perry 
      3  1.1   brezak /*
      4  1.1   brezak  * Copyright (c) 1993 Martin Birgmeier
      5  1.1   brezak  * All rights reserved.
      6  1.1   brezak  *
      7  1.1   brezak  * You may redistribute unmodified or modified versions of this source
      8  1.1   brezak  * code provided that the above copyright notice and this and the
      9  1.1   brezak  * following conditions are retained.
     10  1.1   brezak  *
     11  1.1   brezak  * This software is provided ``as is'', and comes with no warranties
     12  1.1   brezak  * of any kind. I shall in no event be liable for anything that happens
     13  1.1   brezak  * to anyone/anything when using this software.
     14  1.1   brezak  */
     15  1.1   brezak 
     16  1.8    lukem #include <sys/cdefs.h>
     17  1.8    lukem #if defined(LIBC_SCCS) && !defined(lint)
     18  1.8    lukem __RCSID("$NetBSD: erand48.c,v 1.8 2005/06/12 05:21:28 lukem Exp $");
     19  1.8    lukem #endif /* LIBC_SCCS and not lint */
     20  1.8    lukem 
     21  1.3      jtc #include "namespace.h"
     22  1.5    lukem 
     23  1.5    lukem #include <assert.h>
     24  1.5    lukem 
     25  1.1   brezak #include "rand48.h"
     26  1.3      jtc 
     27  1.3      jtc #ifdef __weak_alias
     28  1.7  mycroft __weak_alias(erand48,_erand48)
     29  1.3      jtc #endif
     30  1.1   brezak 
     31  1.1   brezak double
     32  1.1   brezak erand48(unsigned short xseed[3])
     33  1.1   brezak {
     34  1.5    lukem 
     35  1.5    lukem 	_DIAGASSERT(xseed != NULL);
     36  1.5    lukem 
     37  1.2      jtc 	__dorand48(xseed);
     38  1.1   brezak 	return ldexp((double) xseed[0], -48) +
     39  1.1   brezak 	       ldexp((double) xseed[1], -32) +
     40  1.1   brezak 	       ldexp((double) xseed[2], -16);
     41  1.1   brezak }
     42