1/* s_ilogbf.c -- float version of s_ilogb.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16#include "math.h"
17#include "math_private.h"
18
19int
20ilogbf(float x)
21{
22	int32_t hx,ix;
23
24	GET_FLOAT_WORD(hx,x);
25	hx &= 0x7fffffff;
26	if(hx<0x00800000) {
27	    if(hx==0)
28		return FP_ILOGB0;	/* ilogb(0) = FP_ILOGB */
29	    else			/* subnormal x */
30	        for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
31	    return ix;
32	}
33	else if (hx<0x7f800000) return (hx>>23)-127;
34	else if (hx>0x7f800000) return FP_ILOGBNAN;
35	else return INT_MAX;
36}
37DEF_STD(ilogbf);
38