> It came up in a few side conversations. As I understand it, RMS has > decreed that the -On optimizations shall be architecture independent. > That said, there are "generic" optimizations which really only apply > to a single architecture, so there is some precedent for bending this > rule. > > There were also suggestions of making the order of optimizations > command line configurable and allowing dynamically loaded libraries to > register new passes. > > Ollie
This seems unfortunate. I was hoping I might be able to turn on loop unrolling for IA64 at -O2 to improve performance. I have only started looking into this idea but it seems to help performance quite a bit, though it is also increasing size quite a bit too so it may need some modification of the unrolling parameters to make it practical. I notice the OPTIMIZATION_OPTIONS documentation does say: | You should not use this macro to change options that are not | machine-specific. These should uniformly selected by the same | optimization level on all supported machines. Use this macro to enable | machine-specific optimizations. What is the rational for this? Is it a question of making it easier to reproduce a -O2 bug that happens on one machine on a different one too so it is easier to find and fix? Steve Ellcey [EMAIL PROTECTED]
