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From: rfg@paris.ics.uci.edu (Ronald Guilmette)
Newsgroups: comp.std.c
Subject: Interpretation of volatile - two questions
Message-ID: <2604A628.8521@paris.ics.uci.edu>
Date: 19 Mar 90 09:28:08 GMT
Organization: UC Irvine Department of ICS
Lines: 31

Assume you have the following structure:

	struct s {
		char		c1;
		volatile char	c2;
	};

Now assume that you also have:

	struct s *memory_mapped_device_p = (struct s *) 0xffffff80;

Now if you also have:

	void foo ()
	{
		char c;

		c = memory_mapped_device_p->c1;
	}

does the standard (a) permit, (b) require, or (c) prohibit the assignment
statement shown to access the c2 field of the "struct s" pointed to by
memory_mapped_device_p?

This could be important in cases where you have certain locations which
(when read) produce side-effects.


// Ron Guilmette (rfg@ics.uci.edu)
// C++ Entomologist
// Motto:  If it sticks, force it.  If it breaks, it needed replacing anyway.