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
