mirror of https://github.com/0intro/conterm
56 lines
921 B
C
56 lines
921 B
C
/*
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* 64-bit IEEE not-a-number routines.
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* This is big/little-endian portable assuming that
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* the 64-bit doubles and 64-bit integers have the
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* same byte ordering.
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*/
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#include <u.h>
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#include <libc.h>
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#include "nan.h"
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// typedef unsigned long long uvlong;
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// typedef unsigned long ulong;
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static uvlong uvnan = 0x7FF0000000000001ULL;
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static uvlong uvinf = 0x7FF0000000000000ULL;
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static uvlong uvneginf = 0xFFF0000000000000ULL;
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double
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__NaN(void)
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{
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return *(double*)(void*)&uvnan;
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}
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int
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__isNaN(double d)
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{
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uvlong x = *(uvlong*)(void*)&d;
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return (ulong)(x>>32)==0x7FF00000 && !__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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if(sign < 0)
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return *(double*)(void*)&uvinf;
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else
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return *(double*)(void*)&uvneginf;
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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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uvlong x;
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x = *(uvlong*)(void*)&d;
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if(sign == 0)
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return x==uvinf || x==uvneginf;
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else if(sign > 0)
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return x==uvinf;
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else
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return x==uvneginf;
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}
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