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Re: volatile [was: GCC warnings for unused global variables]
Fergus Henderson <fjh@cs.mu.OZ.AU> writes:
| On 04-May-2003, Michael Eager <eager@eagercon.com> wrote:
| > I don't believe there is any requirement that static variables are
| > first set to zero and then set their initial value.
|
| C++98 8.5 [dcl.init] paragraph 6: "The memory occupied by any object
| of static storage duration shall be zero-initialized at program startup
| before any other initialization takes place.".
Which is different from your earlier claim that the *object* is
zero-initialized.
| > They can be
| > created with the initialized value, if that can be calculated at
| > compile time (e.g., if there is no constructor).
|
| That is true for non-volatile variables, but only because the compiler
| can apply the as-if rule. As discussed earlier in this thread, the
| as-if rule does not apply to volatile variables -- the standard prohibits
| implementations from optimizing away accesses to volatile variables.
You keep repeating this false assertion: Quotes have been to specific
text where the standard does actually permit such optimization.
-- Gaby