Path: utzoo!attcan!uunet!convex!mozart!dodson
From: dodson@mozart.uucp (Dave Dodson)
Newsgroups: comp.lang.fortran
Subject: Re: intrinsic functions, math operators (was: i++, i+=1, i=i+1)
Message-ID: <596@convex.UUCP>
Date: 22 Sep 88 14:22:09 GMT
References: <1028@amelia.nas.nasa.gov> <3957@lanl.gov>
Sender: news@convex.UUCP
Reply-To: dodson@mozart.UUCP (Dave Dodson)
Organization: Convex Computer Corporation, Richardson, Tx.
Lines: 14

In article <3957@lanl.gov> jlg@lanl.gov (Jim Giles) writes:
>If I were writing a C compiler, I would certainly do pow() in-line.

Considering the complexity and length of a properly written pow()
routine, it does not appear to me to be practical for the compiler to
in-line it.  It is not adequate to evaluate pow(x,y) as exp(y*log(x))
unless additional precision is used.  See "Software Manual for the
Elementary Functions" by Cody and Waite, for a description of an
appropriate algorithm.

----------------------------------------------------------------------

Dave Dodson    {uiucdcs,sun,uunet,harvard,killer,usenix}!convex!dodson
Convex Computer Corporation      Richardson, Texas      (214) 952-0234