Optimization of conditional access to globals: thread-unsafe?

[skaller]

On Mon, 2007-10-29 at 21:03 +0100, Andi Kleen wrote:
> On Mon, Oct 29, 2007 at 03:51:27PM -0400, Robert Dewar wrote:
> > Sure, well nearly every optimization has some case where it is a 
> > pessimization (one interesting thing that happens is that if you
> > change the length of generated code in *any* way you may be unlucky
> > and cause a systematic instruction cache miss in a loop, inlining
> 
> icache misses are hard in general and agreed the compiler cannot
> do too much about them (except for trying not to generate too bloated
> code in general)

BTW: doesn't this suggest unrolling loops and recursions is
potentially expensive?

-- 
John Skaller <skaller at users dot sf dot net>
Felix, successor to C++: http://felix.sf.net