GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/s_ilogbl.c Lines: 4 17 23.5 %
Date: 2017-11-13 Branches: 2 16 12.5 %

Line Branch Exec Source
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/*	$OpenBSD: s_ilogbl.c,v 1.2 2016/09/12 19:47:02 guenther Exp $	*/
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/*
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 * From: @(#)s_ilogb.c 5.1 93/09/24
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 * ====================================================
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 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 *
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 * Developed at SunPro, a Sun Microsystems, Inc. business.
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 * Permission to use, copy, modify, and distribute this
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 * software is freely granted, provided that this notice
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 * is preserved.
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 * ====================================================
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 */
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#include <sys/types.h>
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#include <machine/ieee.h>
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#include <float.h>
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#include <limits.h>
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#include <math.h>
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int
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ilogbl(long double x)
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{
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	struct ieee_ext *p = (struct ieee_ext *)&x;
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	unsigned long m;
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	int b;
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	if (p->ext_exp == 0) {
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		if ((p->ext_fracl
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#ifdef EXT_FRACLMBITS
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			| p->ext_fraclm
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#endif /* EXT_FRACLMBITS */
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#ifdef EXT_FRACHMBITS
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			| p->ext_frachm
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#endif /* EXT_FRACHMBITS */
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			| p->ext_frach) == 0)
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			return (FP_ILOGB0);
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		/* denormalized */
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		if (p->ext_frach == 0
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#ifdef EXT_FRACHMBITS
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			&& p->ext_frachm == 0
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#endif
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			) {
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			m = 1lu << (EXT_FRACLBITS - 1);
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			for (b = EXT_FRACHBITS; !(p->ext_fracl & m); m >>= 1)
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				b++;
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#if defined(EXT_FRACHMBITS) && defined(EXT_FRACLMBITS)
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			m = 1lu << (EXT_FRACLMBITS - 1);
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			for (b += EXT_FRACHMBITS; !(p->ext_fraclm & m); m >>= 1)
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				b++;
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#endif /* defined(EXT_FRACHMBITS) && defined(EXT_FRACLMBITS) */
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		} else {
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			m = 1lu << (EXT_FRACHBITS - 1);
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			for (b = 0; !(p->ext_frach & m); m >>= 1)
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				b++;
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#ifdef EXT_FRACHMBITS
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			m = 1lu << (EXT_FRACHMBITS - 1);
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			for (; !(p->ext_frachm & m); m >>= 1)
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				b++;
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#endif /* EXT_FRACHMBITS */
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		}
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#ifdef EXT_IMPLICIT_NBIT
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		b++;
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#endif
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		return (LDBL_MIN_EXP - b - 1);
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	} else if (p->ext_exp < (LDBL_MAX_EXP << 1) - 1)
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		return (p->ext_exp - LDBL_MAX_EXP + 1);
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	else if (p->ext_fracl != 0
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#ifdef EXT_FRACLMBITS
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		|| p->ext_fraclm != 0
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#endif /* EXT_FRACLMBITS */
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#ifdef EXT_FRACHMBITS
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		|| p->ext_frachm != 0
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#endif /* EXT_FRACHMBITS */
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		|| p->ext_frach != 0)
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		return (FP_ILOGBNAN);
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	else
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		return (INT_MAX);
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}
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DEF_STD(ilogbl);