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/* s_ilogbf.c -- float version of s_ilogb.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: s_ilogbf.c,v 1.10 2016/08/26 08:20:31 christos Exp $");
#endif
#include <math.h>
#define __TEST_FENV
#include <fenv.h>
#ifndef __HAVE_FENV
#define feraiseexcept(a)
#endif
#include "math_private.h"
int
ilogbf(float x)
{
int32_t hx, ix;
GET_FLOAT_WORD(hx, x);
hx &= 0x7fffffff;
if (hx < 0x00800000) {
if (hx == 0) {
feraiseexcept(FE_INVALID);
return FP_ILOGB0; /* ilogb(0) = 0x80000001 */
}
for (ix = -126, hx <<= 8; hx > 0; hx <<= 1) ix -= 1;
return ix;
}
if (hx < 0x7f800000) {
return (hx >> 23) - 127;
}
feraiseexcept(FE_INVALID);
return isnan(x) ? FP_ILOGBNAN : INT_MAX;
}
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