xref: /freebsd/usr.bin/m4/TEST/sqroot.m4 (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1#	$OpenBSD: sqroot.m4,v 1.3 2003/06/03 02:56:11 millert Exp $
2#	$NetBSD: sqroot.m4,v 1.4 1995/09/28 05:38:01 tls Exp $
3#
4# Copyright (c) 1989, 1993
5#	The Regents of the University of California.  All rights reserved.
6#
7# This code is derived from software contributed to Berkeley by
8# Ozan Yigit.
9#
10# Redistribution and use in source and binary forms, with or without
11# modification, are permitted provided that the following conditions
12# are met:
13# 1. Redistributions of source code must retain the above copyright
14#    notice, this list of conditions and the following disclaimer.
15# 2. Redistributions in binary form must reproduce the above copyright
16#    notice, this list of conditions and the following disclaimer in the
17#    documentation and/or other materials provided with the distribution.
18# 3. Neither the name of the University nor the names of its contributors
19#    may be used to endorse or promote products derived from this software
20#    without specific prior written permission.
21#
22# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32# SUCH DAMAGE.
33#
34
35define(square_root,
36	`ifelse(eval($1<0),1,negative-square-root,
37			     `square_root_aux($1, 1, eval(($1+1)/2))')')
38define(square_root_aux,
39	`ifelse($3, $2, $3,
40		$3, eval($1/$2), $3,
41		`square_root_aux($1, $3, eval(($3+($1/$3))/2))')')
42