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Re: tree-ssa performance (was: treelang fix for rs6000 / treelangnot proper front end)
On Tue, 2003-06-10 at 11:39, Gerald Pfeifer wrote:
> [ gcc-patches -> gcc ]
>
> On Tue, 10 Jun 2003, Steven Bosscher wrote:
> >> (See PR8361 for an example.)
> > That's not quite fair on tree-ssa. It really isn't that slow AFAICT.
>
> It _is_, at least right now. About factor of two for -O2 and -O3.
>
> My last tests were on Friday and I just redid them from scratch with
> current mainline and current tree-ssa:
>
FWIW, The very limited amount of compile time experience Ive got (an
early cut at reducing compile time for out-of-SSA) indicated that
tree-ssa requires more memory. If you have a smaller memory machine, its
compile times shoot up quite a bit due to swapping. On machines where it
can compile without swapping, compiles times are not so bad.
I suspect thats why Diegos spec runs aren't too bad, its probably a big
machine :-) I've had files on one machine at least double in compile
time, and the same file on a bigger machine is pretty close to the
original.
Andrew