GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/s_rintl.c Lines: 11 15 73.3 %
Date: 2017-11-13 Branches: 2 6 33.3 %

Line Branch Exec Source
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/*	$OpenBSD: s_rintl.c,v 1.2 2016/09/12 19:47:02 guenther Exp $	*/
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/*-
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 * Copyright (c) 2008 David Schultz <das@FreeBSD.ORG>
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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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 <math.h>
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#if LDBL_MAX_EXP != 0x4000
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/* We also require the usual bias, min exp and expsign packing. */
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#error "Unsupported long double format"
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#endif
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#define	BIAS	(LDBL_MAX_EXP - 1)
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static const float
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shift[2] = {
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#if LDBL_MANT_DIG == 64
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	0x1.0p63, -0x1.0p63
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#elif LDBL_MANT_DIG == 113
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	0x1.0p112, -0x1.0p112
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#else
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#error "Unsupported long double format"
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#endif
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};
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static const float zero[2] = { 0.0, -0.0 };
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long double
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rintl(long double x)
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{
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	union {
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		long double e;
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		struct ieee_ext bits;
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	} u;
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	uint32_t expsign;
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	int ex, sign;
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	u.e = x;
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	expsign = (u.bits.ext_sign << 15) | u.bits.ext_exp;
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	ex = expsign & 0x7fff;
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	if (ex >= BIAS + LDBL_MANT_DIG - 1) {
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		if (ex == BIAS + LDBL_MAX_EXP)
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			return (x + x);	/* Inf, NaN, or unsupported format */
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		return (x);		/* finite and already an integer */
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	}
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	sign = expsign >> 15;
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	/*
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	 * The following code assumes that intermediate results are
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	 * evaluated in long double precision. If they are evaluated in
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	 * greater precision, double rounding may occur, and if they are
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	 * evaluated in less precision (as on i386), results will be
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	 * wildly incorrect.
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	 */
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	x += shift[sign];
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	x -= shift[sign];
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	/*
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	 * If the result is +-0, then it must have the same sign as x, but
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	 * the above calculation doesn't always give this.  Fix up the sign.
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	 */
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	if (ex < BIAS && x == 0.0L)
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		return (zero[sign]);
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	return (x);
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}
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DEF_NONSTD(rintl);