Optimization of conditional access to globals: thread-unsafe?

[Michael Matz]

Hi,

On Mon, 29 Oct 2007, Tomash Brechko wrote:

> Still, I believe the example proves the general idea.  It shows that 
> speculative store is never safe, because every 'if' may be an 'if not 
> read-only'-one.

It is safe if there's another dominating store outside the control region.  
Apart from that I reluctantly agree (i.e. it's not enough if there's any 
dominating access through the pointer in question, it must be a store).


Ciao,
Michael.