🚀 go-pugleaf

In article <4198@lupine.NCD.COM>, rfg@NCD.COM (Ron Guilmette) writes:
|> In article <NGO.91Feb19114034@tammy.harvard.edu> ngo@tammy.harvard.edu (Tom Ngo) writes:
|> +
|> +Background information to this posting was in a very recent summary.
|> +
|> ...
|> +    ~volatile   Do allow optimization on this object [even if the
|> +                enclosing object is declared volatile].
|> +
|> +Joe Buck <jbuck@galileo.berkeley.edu> was against ~volatile on the
|> +grounds that it would add virtually nothing to the language; it would
|> +"give a tiny bit of useful information to an optimizing compiler,
|> +[but] it would gain nothing in expressive capability."
|> +
|> +Joe Buck and Ron Guilmette <rfg@ncd.com> felt that symmetry and
|> +simplicity of implementation might be good reasons to permit a
|> +~volatile specifier.

Tom makes it look like I contradict myself.  No, I meant that ~volatile
doesn't get you much extra but you may as well throw it in to maintain
a uniform grammar, since volatile may appear anywhere that const can
at present.

|> One could argue that ~volatile has very little usefulness, however the
|> same could be said for `volatile' itself.  Does that mean that we should
|> get rid of `volatile'?  I think not.

There are places that volatile is needed, especially when interacting
with hardware, signals, and interrupt service routines.  The "pre-volatile"
trick was putting in a comment saying "WARNING: don't use -O on this code".

--
Joe Buck
jbuck@galileo.berkeley.edu	 {uunet,ucbvax}!galileo.berkeley.edu!jbuck