usr/src/usr.bin/m4/TEST/sqroot.m4

#
# Copyright (c) 1989, 1993
#       The Regents of the University of California.  All rights reserved.
#
# This code is derived from software contributed to Berkeley by
# Ozan Yigit.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#       This product includes software developed by the University of
#       California, Berkeley and its contributors.
# 4. Neither the name of the University nor the names of its contributors
#    may be used to endorse or promote products derived from this software
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# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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#       @(#)sqroot.m4   8.1 (Berkeley) 6/6/93
#

define(square_root,
        `ifelse(eval($1<0),1,negative-square-root,
                             `square_root_aux($1, 1, eval(($1+1)/2))')')
define(square_root_aux,
        `ifelse($3, $2, $3,
                $3, eval($1/$2), $3,
                `square_root_aux($1, $3, eval(($3+($1/$3))/2))')')