GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/s_nan.c Lines: 0 20 0.0 %
Date: 2017-11-13 Branches: 0 16 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: s_nan.c,v 1.14 2016/09/12 19:47:02 guenther Exp $	*/
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/*-
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 * Copyright (c) 2007 David Schultz
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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 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 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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 * $FreeBSD: src/lib/msun/src/s_nan.c,v 1.2 2007/12/18 23:46:32 das Exp $
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 */
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#include <sys/types.h>
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#include <ctype.h>
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#include <endian.h>
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#include <float.h>
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#include <math.h>
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#include <stdint.h>
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#include <strings.h>
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#include "math_private.h"
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/*
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 * OpenBSD's ctype doesn't have digittoint, so we define it here.
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 */
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static int
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_digittoint(int c)
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{
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	if (!isxdigit(c))
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		return 0;
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	if (isdigit(c))
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		return c - '0';
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	else
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		return isupper(c) ? c - 'A' + 10 : c - 'a' + 10;
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}
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/*
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 * Scan a string of hexadecimal digits (the format nan(3) expects) and
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 * make a bit array (using the local endianness). We stop when we
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 * encounter an invalid character, NUL, etc.  If we overflow, we do
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 * the same as gcc's __builtin_nan(), namely, discard the high order bits.
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 *
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 * The format this routine accepts needs to be compatible with what is used
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 * in contrib/gdtoa/hexnan.c (for strtod/scanf) and what is used in
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 * __builtin_nan(). In fact, we're only 100% compatible for strings we
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 * consider valid, so we might be violating the C standard. But it's
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 * impossible to use nan(3) portably anyway, so this seems good enough.
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 */
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void
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_scan_nan(uint32_t *words, int num_words, const char *s)
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{
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	int si;		/* index into s */
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	int bitpos;	/* index into words (in bits) */
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	bzero(words, num_words * sizeof(uint32_t));
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	/* Allow a leading '0x'. (It's expected, but redundant.) */
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	if (s[0] == '0' && (s[1] == 'x' || s[1] == 'X'))
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		s += 2;
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	/* Scan forwards in the string, looking for the end of the sequence. */
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	for (si = 0; isxdigit((unsigned char)s[si]); si++)
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		;
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	/* Scan backwards, filling in the bits in words[] as we go. */
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#if BYTE_ORDER == LITTLE_ENDIAN
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	for (bitpos = 0; bitpos < 32 * num_words; bitpos += 4) {
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#else
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	for (bitpos = 32 * num_words - 4; bitpos >= 0; bitpos -= 4) {
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#endif
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		if (--si < 0)
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			break;
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		words[bitpos / 32] |= _digittoint((unsigned char)s[si]) << (bitpos % 32);
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	}
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}
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double
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nan(const char *s)
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{
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	union {
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		double d;
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		uint32_t bits[2];
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	} u;
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	_scan_nan(u.bits, 2, s);
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#if BYTE_ORDER == LITTLE_ENDIAN
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	u.bits[1] |= 0x7ff80000;
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#else
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	u.bits[0] |= 0x7ff80000;
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#endif
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	return (u.d);
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}
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DEF_STD(nan);
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LDBL_MAYBE_UNUSED_CLONE(nan);
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float
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nanf(const char *s)
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{
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	union {
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		float f;
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		uint32_t bits[1];
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	} u;
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	_scan_nan(u.bits, 1, s);
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	u.bits[0] |= 0x7fc00000;
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	return (u.f);
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}