55 lines
610 B
C
55 lines
610 B
C
#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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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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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 !isInf(d, 0);
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}
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double
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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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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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