On Mar 22, 2007, at 11:03 AM, Johnny Billquist wrote:

> No good. The compiler is still allowed to make optimizations on the  
> accesses if you don't declare it volatile. And that might cause the  
> code to break anyway. It's not only a cache problem.

No, the compiler is not allowed to keep cached in a register a memory  
access across a function call, precisely because it cannot know if  
that function call modifies the memory.

-- thorpej