Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!hc!lanl!jlg
From: jlg@lanl.gov (Jim Giles)
Newsgroups: comp.lang.fortran
Subject: Re: Fortran versus C for numerical analysis
Message-ID: <3064@lanl.gov>
Date: 31 Aug 88 18:03:17 GMT
References: <893@amelia.nas.nasa.gov>
Organization: Los Alamos National Laboratory
Lines: 21

From article <893@amelia.nas.nasa.gov>, by fouts@lemming.nas.nasa.gov.nas.nasa.gov (Marty Fouts):
> I am looking for opinions of experienced
> numerical/scientific/engineering programmers along the lines of why
> Fortran is a better language than C for numerical analysis.

The fact that C parenthesis don't force execution order is sufficient
to exclude C from use in some instances.  The suggestion has been made 
to force execution order by introducing more temporary variables, but
this costs time (to store the variables), space (for the variables),
and/or additional compiler complexity (to recognize that the variables
are temporaries).  A really 'smart' compiler might even optimize out
temporary variables and then reorder the execution.  

At any rate, the ability to force a particular order of expression
evaluation is sometimes VERY important.  It is often important in a 
time-critical part of the code (so extra temporaries are 'out').
The lack of SOME mechanism to do this is a deficiency in C.  (Note:
I don't maintain that significant parenthesis is the ONLY or even the
BEST way, but to have NO WAY is certainly bad.)

J. Giles
Los Alamos