[Patch, fortran] PR24518 and PR24520 - Improvements to MOD and

[Tim Prince]

Paul Thomas wrote:
> Tim,
> 
>> Itanium linux results showed no significant difference between 
>> in-lined and library results, except for a  large gain at all loop 
>> lengths for in-lining the sparse dot product.  
>>
> Is that for real(8) or real(16)?  Can you explain the lack of a difference?
> 
> Paul
> 
> 
This was for default real, using options -O3 -funroll-loops 
-frename-registers. I should have tried -ffast-math in the hope of 
eliminating SIR stalls.  Default real actually has more potential 
performance problems than double precision on Itanium, some of which gcc 
has no way to recognize.
I wasn't aware of a gfortran real(16) implementation for Itanium. 
Supporting that correctly in ia64.md would be a great deal of work.  I 
have looked extensively at ia64.md in the past, and there was support 
for real(10) but not real(16).
I'll try to look into the performance question.  If -frename-registers 
is not having the intended effect, that would explain ineffectiveness of 
other optimizations.
Sorry for the delay, I'm working from a hotel and from SC05, and just 
now got my emailer configuration reconciled.