Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!convex!convex.COM
From: patrick@convex.COM (Patrick F. McGehearty)
Newsgroups: comp.lang.fortran
Subject: Re: Side effects in boolean expressions
Message-ID: <105015@convex.convex.com>
Date: 16 Aug 90 18:00:14 GMT
References: <2041@key.COM> <60198@lanl.gov>
Sender: news@convex.com
Reply-To: patrick@convex.COM (Patrick F. McGehearty)
Organization: Convex Computer Corporation; Richardson, TX
Lines: 17


In article <60198@lanl.gov> jlg@lanl.gov (Jim Giles) writes:
...stuff about if and or
>> 	IF ((X .LT. 0.) .OR. (SQRT(X) .LT. 10.0)) ...
>
>In this example, of course, it is more efficient to do the test as
>follows anyway:
>
>      if (x < sqrt(10.0)) then ...
>
>This has the same effect and completely avoids the problem.
Actually,
	IF ( X .LT. 100.0) ...
will have the same effect as the original and avoid the problem.

Which shows why people don't make obvious code optimizations.
ANY changes to source or algorithm carry a risk of error.  Sigh.