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#include <limits.h>
#include "libm.h"
int ilogb(double x)
{
#pragma STDC FENV_ACCESS ON
union {
double f;
uint64_t i;
} u = { x };
uint64_t i = u.i;
int e = i >> 52 & 0x7ff;
if (!e) {
i <<= 12;
if (i == 0) {
FORCE_EVAL(0 / 0.0f);
return FP_ILOGB0;
}
/* subnormal x */
for (e = -0x3ff; i >> 63 == 0; e--, i <<= 1)
;
return e;
}
if (e == 0x7ff) {
FORCE_EVAL(0 / 0.0f);
return i << 12 ? FP_ILOGBNAN : INT_MAX;
}
return e - 0x3ff;
}
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