Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!decwrl!apple!sun-barr!newstop!sun!amdahl!key!sjc
From: sjc@key.COM (Steve Correll)
Newsgroups: comp.lang.fortran
Subject: Re: Side effects in boolean expressions
Message-ID: <2047@key.COM>
Date: 16 Aug 90 19:20:56 GMT
References: <2022@key.COM> <59110@lanl.gov> <2041@key.COM> <140684@sun.Eng.Sun.COM>
Organization: Key Computer Labs, Fremont, CA
Lines: 17

In article <140684@sun.Eng.Sun.COM>, wsb@boise.Eng.Sun.COM (Walt Brainerd) writes:
> In article <2041@key.COM>, sjc@key.COM (Steve Correll) writes:
> > ... the C code is legal and its behavior predictable; the Fortran is neither:
> >                                                       ^^^^^^^^^^^^^^^^^^^^^^
> > 	if ((x < 0.0) || (sqrt(x) < 10.0)) ...
> > 	IF ((X .LT. 0.) .OR. (SQRT(X) .LT. 10.0)) ...
> > 
> The Fortran code certainly is legal...

I believe that a program which could cause the translator to invoke SQRT with
a negative argument fails to conform to the Fortran 77 standard, because
section 13.10.1, page 15-28 of the X3.9-1978 says:

   Square Root: The value of the argument of SQRT and DSQRT must be greater
   than or equal to zero.
-- 
...{sun,pyramid}!pacbell!key!sjc 				Steve Correll