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From: Purtill@MIT-MULTICS.arpa
Newsgroups: comp.lang.c
Subject: Sequence points
Message-ID: <6840@brl-adm.ARPA>
Date: Sun, 12-Apr-87 15:34:11 EST
Article-I.D.: brl-adm.6840
Posted: Sun Apr 12 15:34:11 1987
Date-Received: Tue, 14-Apr-87 00:05:46 EST
Sender: news@brl-adm.ARPA
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It would really help if some of the people complaining about the
standard would get a copy.  Some people seem to have the idea that the
standard allows the compiler to do anything it wants in the way of
rearranging expressions, eliminating temps, and so on.  This is not
true, there are things called sequence points which limit the compiler's
optimizations.  I won't go into details as my copy of the standard
(excuse me, draft proposed standard) is (1) somewhat old (from when they
were free) and (2) elsewhere.  But do look at the standard before
complaining bitterly.  (Note that limiting the optimization is not
necessarily a loser; the implementation is free to provide a flag to do
additional (nonANSI) optimizations, but when that flag is used, it
wouldn't be an ANSI compiler.  (The Convex compiler has a flag to do
"potentially unsafe" optimizations, for instance.))

^.-.^ Mark Purtill
((")) Purtill -at Multics.MIT.edu