forgot to reply the the list... From: Ian Lance Taylor <iant@xxxxxxxxxx> Subject: Re: cost of -fnon-call-exceptions To: "Kenny Simpson" <theonetruekenny@xxxxxxxxx> Date: Friday, September 10, 2010, 3:48 PM Kenny Simpson <theonetruekenny@xxxxxxxxx> writes: > Meaning every memory reference is treated as though it were volatile ? > Any rough idea how much this would hurt ? Please reply to the mailing list, not just to me. Thanks. It's not really accurate to say that every memory reference is treated as volatile. A memory reference which is not used will still be removed from the program. Also the compiler knows that many memory references can not trap--e.g., references to variables stored on the stack. It would be more accurate to say that the compiler will not in general reorder indirections through pointers. How much that hurts depends a lot on your processor. On modern x86 other than Atom, it doesn't hurt much, because the processors are not in-order and have sophisticated memory reordering. On Atom it will hurt, but how much it will hurt depends on your application. I don't think there is any one answer. Ian
