On Fri, 10 Mar 2006, Andrew Pinski wrote: > > On Mar 10, 2006, at 3:34 PM, Alexey Starovoytov wrote: > > > Few major infrastructure features needs to be done first. > > Like? Please give examples. If link time optimizations, > that is already starting to be worked on.
I doesn't look that my opinion here worth even 1 cent, but here are few things: - inter-proc (link time) opt I think LLVM is a better approach. - 2nd link time opt not re-optimization like above, but asm code optimizations. Looks like LLVM is targeting that as well. Check -xlinkopt flag and BIT - profile driven opt Great progress in 4.1. I'm very interested to see how you can match it with link time opts. - value profiling doesn't look anything is done - openmp I think it needs to be fully platform dependent, but anyway. Certainly would be interesting to compare with Sun's approach. - struct reorg opts very intersting item on gcc's todo list - loop opts Not sure what exactly is being done, but what I can see in 4.0 and 4.1 needs to be improved. Try -xloopinfo for verbosity. - prefetch It rather hurts performance when I tried it. Check -xprefetch* flags - struct type aliasing Great progress in 4.1, but still much behind Sun. Check -xalias_level flag - auto parallelization doesn't look anything is being done here. Check -xautopar - -ffast-math just compare it with Sun's -fsimple=2 - optimized inline assembler All of the above is done by sun compiler and gcc4ss (except openmp). A lot of other things are coming. Also I don't want to start "tree vs orc" flame, but it seems that Sun's IR is better suited for the above opts. Ok. Ok. It's not. Alex. > > -- Pinski > >
