Re: [Fwd: Re: Polyhedron benchmark on Opteron]

[Tobias Burnus <tobias dot burnus at physik dot fu-berlin dot de>]

Hi,

FX Coudert wrote:
> Relaying Tobias' mail, as he is having problems with the mailing-list...
Trying yet another method to post ...

>> ISET(1) = huge(ISET)
>> do i=1,nodes
>>   if(iset(1) > dtemp(1)) iset(1) = i
>> end do
>>
> 
> Isn't it iset > dtemp(i)? Otherwise, I do understand why the compiler
> can gain so much time :)

Ups. This comes from posting from a different computer than running the
program and typing in the changes. I actually used
   if(iset(1)>dtemp(i)) iset(1) = i


> Otherwise, I do understand why the compiler can gain so much time.

Try it yourself. I don't understand it either, but it seems to be indeed
the case. (Actually, I really wonder why no other compiler is inlining
it, if the gain is that big. -- gfortran would be then 5 times as fast
as Absoft or Pathscale?!?)

After doing these changes, Intel is again faster: 0.58s instead of
gfortran's 1.233s.

Tobias