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/* $OpenBSD: drand48.c,v 1.7 2015/09/14 13:30:17 guenther Exp $ */ |
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/* |
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* Copyright (c) 1993 Martin Birgmeier |
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* All rights reserved. |
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* |
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* You may redistribute unmodified or modified versions of this source |
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* code provided that the above copyright notice and this and the |
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* following conditions are retained. |
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* |
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* This software is provided ``as is'', and comes with no warranties |
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* of any kind. I shall in no event be liable for anything that happens |
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* to anyone/anything when using this software. |
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*/ |
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#include <math.h> |
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#include "rand48.h" |
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double |
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drand48(void) |
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{ |
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if (__rand48_deterministic == 0) { |
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unsigned short rseed[3]; |
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arc4random_buf(rseed, sizeof rseed); |
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return ldexp((double) rseed[0], -48) + |
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ldexp((double) rseed[1], -32) + |
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ldexp((double) rseed[2], -16); |
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} |
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return erand48(__rand48_seed); |
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} |