xref: /openbsd-src/lib/libc/stdio/floatio.h (revision 63161a5d6627aaea81f63687903f6ec57ec366d4)
1*63161a5dSguenther /*	$OpenBSD: floatio.h,v 1.5 2015/09/14 12:49:33 guenther Exp $	*/
2df930be7Sderaadt 
3df930be7Sderaadt /*-
4df930be7Sderaadt  * Copyright (c) 1990, 1993
5df930be7Sderaadt  *	The Regents of the University of California.  All rights reserved.
6df930be7Sderaadt  *
7df930be7Sderaadt  * This code is derived from software contributed to Berkeley by
8df930be7Sderaadt  * Chris Torek.
9df930be7Sderaadt  *
10df930be7Sderaadt  * Redistribution and use in source and binary forms, with or without
11df930be7Sderaadt  * modification, are permitted provided that the following conditions
12df930be7Sderaadt  * are met:
13df930be7Sderaadt  * 1. Redistributions of source code must retain the above copyright
14df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer.
15df930be7Sderaadt  * 2. Redistributions in binary form must reproduce the above copyright
16df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer in the
17df930be7Sderaadt  *    documentation and/or other materials provided with the distribution.
186580fee3Smillert  * 3. Neither the name of the University nor the names of its contributors
19df930be7Sderaadt  *    may be used to endorse or promote products derived from this software
20df930be7Sderaadt  *    without specific prior written permission.
21df930be7Sderaadt  *
22df930be7Sderaadt  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23df930be7Sderaadt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24df930be7Sderaadt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25df930be7Sderaadt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26df930be7Sderaadt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27df930be7Sderaadt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28df930be7Sderaadt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29df930be7Sderaadt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30df930be7Sderaadt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31df930be7Sderaadt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32df930be7Sderaadt  * SUCH DAMAGE.
33df930be7Sderaadt  */
34df930be7Sderaadt 
35df930be7Sderaadt /*
36df930be7Sderaadt  * Floating point scanf/printf (input/output) definitions.
37df930be7Sderaadt  */
38df930be7Sderaadt 
39df930be7Sderaadt /* 11-bit exponent (VAX G floating point) is 308 decimal digits */
40df930be7Sderaadt #define	MAXEXP		308
41df930be7Sderaadt /* 128 bit fraction takes up 39 decimal digits; max reasonable precision */
42df930be7Sderaadt #define	MAXFRACT	39
437b36286aSmartynas 
447b36286aSmartynas /*
457b36286aSmartynas  * MAXEXPDIG is the maximum number of decimal digits needed to store a
467b36286aSmartynas  * floating point exponent in the largest supported format.  It should
477b36286aSmartynas  * be ceil(log10(LDBL_MAX_10_EXP)) or, if hexadecimal floating point
487b36286aSmartynas  * conversions are supported, ceil(log10(LDBL_MAX_EXP)).  But since it
497b36286aSmartynas  * is presently never greater than 5 in practice, we fudge it.
507b36286aSmartynas  */
517b36286aSmartynas #define	MAXEXPDIG	6
527b36286aSmartynas #if LDBL_MAX_EXP > 999999
537b36286aSmartynas #error "floating point buffers too small"
547b36286aSmartynas #endif
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