Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!pasteur!agate!ig!arizona!debray
From: debray@arizona.edu (Saumya Debray)
Newsgroups: comp.lang.prolog
Subject: Re: "A Note on the Speed of Prolog"
Keywords: prolog execution speed
Message-ID: <6366@megaron.arizona.edu>
Date: 20 Jul 88 16:00:09 GMT
References: <6251@megaron.arizona.edu> <564@ecrcvax.UUCP>
Organization: U of Arizona CS Dept, Tucson
Lines: 18

In article <564@ecrcvax.UUCP>, micha@ecrcvax.UUCP (Micha Meier) writes:
> I'm sure everybody agrees that Quintus Prolog is a very fast Prolog,
> but our compiler, written in C, is about 10 times faster than Quintus
> compiler written in Prolog ...

I'm not surprised at that: you'd expect some performance loss in going
from a low-level to a high-level language.  A compiler written in
Prolog would have a fair amount of structure copying, runtime type
checking, tagging/untagging of operands, etc., that you wouldn't find
in the corresponding C code.  What I found interesting about the
SIGPLAN Notices article I referred to originally was that despite the
overhead of runtime type checking etc., the Prolog code came as close
as it did to the performance of code written in a strongly typed
imperative language.
-- 
Saumya Debray		CS Department, University of Arizona, Tucson

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