Xref: utzoo comp.arch:16958 comp.lang.misc:5098
Newsgroups: comp.arch,comp.lang.misc
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Compiler Costs
Message-ID: <1990Jul6.161158.1297@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <1797@apctrc.UUCP>
Date: Fri, 6 Jul 90 16:11:58 GMT

In article <1797@apctrc.UUCP> zrra07@backus (Randall R. Appleton) writes:
>I have a simple question:  Does anyone know what sort of speed-up
>on gets by going from a good implementation of some algorithm in a
>third generation language (C, Fortran) and a good optimizing compiler
>to hand-coded assembly?

It can be negative.  Good optimizing compilers can often do a better
job on large bodies of code than humans can.  Small code fragments
often do better when carefully crafted by humans, although this is
a very time-consuming activity.

Improving the algorithm is usually a more cost-effective way of boosting
performance.
-- 
"Either NFS must be scrapped or NFS    | Henry Spencer at U of Toronto Zoology
must be changed."  -John K. Ousterhout |  henry@zoo.toronto.edu   utzoo!henry