1#include <limits.h>
 2#include "libm.h"
 3
 4int ilogbf(float x)
 5{
 6	#pragma STDC FENV_ACCESS ON
 7	union {float f; uint32_t i;} u = {x};
 8	uint32_t i = u.i;
 9	int e = i>>23 & 0xff;
10
11	if (!e) {
12		i <<= 9;
13		if (i == 0) {
14			FORCE_EVAL(0/0.0f);
15			return FP_ILOGB0;
16		}
17		/* subnormal x */
18		for (e = -0x7f; i>>31 == 0; e--, i<<=1);
19		return e;
20	}
21	if (e == 0xff) {
22		FORCE_EVAL(0/0.0f);
23		return i<<9 ? FP_ILOGBNAN : INT_MAX;
24	}
25	return e - 0x7f;
26}