64 lines
1.0 KiB
C
64 lines
1.0 KiB
C
/*
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* This file is part of the UCB release of Plan 9. It is subject to the license
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* terms in the LICENSE file found in the top-level directory of this
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* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
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* part of the UCB release of Plan 9, including this file, may be copied,
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* modified, propagated, or distributed except according to the terms contained
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* in the LICENSE file.
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*/
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#include <u.h>
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#include <libc.h>
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#define NANEXP (2047<<20)
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#define NANMASK (2047<<20)
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#define NANSIGN (1<<31)
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double
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jehanne_NaN(void)
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{
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FPdbleword a;
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a.hi = NANEXP;
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a.lo = 1;
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return a.x;
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}
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int
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jehanne_isNaN(double d)
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{
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FPdbleword a;
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a.x = d;
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if((a.hi & NANMASK) != NANEXP)
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return 0;
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return !jehanne_isInf(d, 0);
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}
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double
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jehanne_Inf(int sign)
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{
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FPdbleword a;
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a.hi = NANEXP;
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a.lo = 0;
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if(sign < 0)
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a.hi |= NANSIGN;
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return a.x;
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}
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int
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jehanne_isInf(double d, int sign)
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{
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FPdbleword a;
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a.x = d;
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if(a.lo != 0)
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return 0;
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if(a.hi == NANEXP)
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return sign >= 0;
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if(a.hi == (NANEXP|NANSIGN))
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return sign <= 0;
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return 0;
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}
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