> > I agree with the idea (I think it's a necessary change, or put
> > differently, an improvement, even though I may not be convinced that it
> > is a *sufficient* improvement; but let's not rehash all that here
> > again); however, I think the implementation is not the greatest.
> >
> > Volatile-qualifying the local variables does not seem useful for
> > anything. It's fine -- actually: it's beneficial -- if the compiler
> > optimizes accesses to those locals -- being on the stack -- as heavily
> > as it can. In other words, those parts of the patch look like a small
> > performance regression.
I did experiment using MSVC compiler with below code:
int main () {
int x;
x = 3;
return 0;
}
If building the above code in optimized mode, the disassembly does not contain
any reference to local variable x.
But if I changed "int x" to "volatile int x", the compiler does not optimize
out the
assignment of x.
So, it means the "volatile" matters even when it applies local variables.
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