Path: utzoo!mnetor!uunet!husc6!mailrus!ames!amdahl!nsc!taux01!orr
From: orr@taux01.UUCP (Orr Michael )
Newsgroups: comp.lang.pascal
Subject: Re:  Global variables
Message-ID: <529@taux01.UUCP>
Date: 28 Mar 88 17:56:30 GMT
References: <12654@brl-adm.ARPA>
Reply-To: orr@taux01.UUCP (Orr Michael )
Organization: National Semiconductor (Israel) Ltd.
Lines: 7
Keywords: gloabl optimizing compilers
Summary: gloabl vars reduce optimization oppurtunities

As one of a team of compiler-writers, including a pascal compiler,
let me note that global variables reduce the compiler's room for
optimization. this is because any time you erite through a pointer,
potentially you may be changing the value of any global var, so the
compiler is prevented from doing a lot of usefull optimizations on
that var. (e.g. allocate the variable in a machine register)
					Michael Orr