kaguya
25 lines
384 B
C
25 lines
384 B
C
#include <math.h>
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#include <stdint.h>
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double frexp(double x, int *e)
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{
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union { double d; uint64_t i; } y = { x };
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int ee = y.i>>52 & 0x7ff;
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if (!ee) {
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if (x) {
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x = frexp(x*0x1p64, e);
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*e -= 64;
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} else *e = 0;
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return x;
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} else if (ee == 0x7ff) {
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*e = 0;
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return x;
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}
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*e = ee - 0x3fe;
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y.i &= 0x800fffffffffffffull;
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y.i |= 0x3fe0000000000000ull;
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return y.d;
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}
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