2009 Update

["C. Bergström"]

Peter Chubb wrote:
>>>>>> "Anton" == Anton Shterenlikht <mexas at bristol.ac.uk> writes:
>>>>>>             
>
> Anton> On Sat, Nov 07, 2009 at 05:26:27PM -0500, "C. Bergström" wrote:
>
> Anton> There are 6 ia64 systems on top500 list (details below). All
> Anton> run linux, of course. But these organisations must use very
> Anton> good compilers, and, at least for nuclear codes (systems 71 and
> Anton> 96), these will be f90-f95 or even f2003 (I don't know of any
> Anton> f2008) compilers. Perhaps they do use PathScale and forget
> Anton> about GCC..
>
> Most use the Intel compiler, and heavy hand-optimization of inner
> loops using tools like vTune.
>
> Gelato put a lot of effort into imprving gcc for IA64 -- gcc 4.x is
> miles better than gcc 3.x -- but there's still a lot that could be done
> with low-level instruction scheduling.
>
>   
I do not normally discourage people to work on other compilers, but 
working on GCC for IA64 is a complete waste of time.  With that I do 
agree the current situation for IA64 is less than ideal.. I'm happy to 
hear complaints and do what is within my resources and capability to fix..

Small notes..
    a) PathScale doesn't currently support IA64
    b) I would like to merge in some code that would give us a near 
optimal CG for IA64.  That in combination with a couple other things 
would hopefully bring us in the same ballpark as the Intel IA64 
compiler.  (Pure speculation as I don't know this target very well or 
current state of Intel compiler)
    c) We're happy to help test and verify changes for IA64 with the 
PathScale QA harness, but need to acquire hardware.  This is something I 
may personally have money for and can put in our datacenter, but there 
is currently no company budget.


./C