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From: jsdy@hadron.UUCP (Joseph S. D. Yao)
Newsgroups: comp.lang.c
Subject: Re: does \"volatile\" cover this?
Message-ID: <410@hadron.UUCP>
Date: Sat, 3-Jan-87 09:04:40 EST
Article-I.D.: hadron.410
Posted: Sat Jan  3 09:04:40 1987
Date-Received: Sat, 3-Jan-87 21:37:47 EST
References: <2028@brl-adm.ARPA>
Reply-To: jsdy@hadron.UUCP (Joseph S. D. Yao)
Organization: Hadron, Inc., Fairfax, VA
Lines: 16
Summary: Sequence points

From an older X3J11 (my new copy is "in the mail"):

6. STATEMENTS
... Completion of the evaluation of the expression [ in if (expr) ... ]
is a sequence point.
6.2 Expression and null statements
... The terminating semicolon is a sequence point.

Hope this makes you happy.  Your situation (two sequential
assignments to the same location) is exactly one of the
situations for which "volatile" was invented, to prevent
"intelligent" optimisers from doing clever things to it.
-- 

	Joe Yao		hadron!jsdy@seismo.{CSS.GOV,ARPA,UUCP}
			jsdy@hadron.COM (not yet domainised)