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From: hen@bu-cs.UUCP
Newsgroups: comp.lang.c
Subject: Parenthesis
Message-ID: <6663@bu-cs.BU.EDU>
Date: Fri, 17-Apr-87 09:40:00 EST
Article-I.D.: bu-cs.6663
Posted: Fri Apr 17 09:40:00 1987
Date-Received: Sat, 18-Apr-87 05:35:56 EST
References: <1100@ius2.cs.cmu.edu>
Reply-To: hen@bu-cs.UUCP (Wm. H. Henneman)
Distribution: na
Organization: Boston Univ. CS Dept.
Lines: 30
Summary: Compiler Directive Considered Dangerous

Many people who object to the use of unary plus to preserve order
are advocating some sort of compiler directive such as

#immune2optimization
	...
	{ code which you think you did real good }
	...
#ok2optimize

I don't understand what this is supposed to mean - is the code only
exempt from explicit reordering, but a candidate for common
subexpression elimination?  Can the optimizer do code hoisting?
Constant rippling into the immune section? Constant rippling out of
the immune section?  Or os the directive supposed to take arguments,
so the code looks like


#immune2optimization reordering,rippling,hoisting,jamming,unscrolling
	...
	{ code which you think you did real good }
	...
#ok2optimize

If the latter is what people have in mind, can these things be nested?

Thanks, folks, but I think I prefer unary plus.  I may or may not
think it makes my listing look ugly, but at least I can understand how
any when to use it.
			Bill Henneman
			Gnurd in Residence