[Bug target/112919] LoongArch: Alignments in tune parameters are not precise and they regress performance

["chenglulu at loongson dot cn" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112919

--- Comment #14 from chenglulu <chenglulu at loongson dot cn> ---
(In reply to chenglulu from comment #13)
> (In reply to Xi Ruoyao from comment #9)
> > (In reply to chenglulu from comment #8)
> > > (In reply to Xi Ruoyao from comment #7)
> > > > Any update? :)
> > > 
> > > Well, I haven't run it yet. Since this does not have a big impact on the
> > > spec score, I am currently testing it on a single-channel machine, so the
> > > test time will be longer.
> > > I will reply here as soon as the results are available.
> > 
> > Can we determine on LA664 if the current default alignment is better than
> > not aligning at all?  Coremarks results suggest the current default is even
> > worse than not aligning, but arguably Coremarks is far different from real
> > workloads. However if the current default is not better than not aligning
> > (or the difference is only marginal and is likely covered up by some random
> > fluctuation) we can disable the aligning for LA664.
> > 
> > (Maybe we and the HW engineers have done some repetitive work or even some
> > work cancelling each other out :(. )
> 
> The results of spec2006 on 3A6000 were obtained, I removed the more volatile
> test items, '-falign-loops=8 -falign-functions=8 -falign-jumps=32
> -falign-lables=4' this set of parameters got the highest score. This is the
> same combination of parameters as the coremark tested by Xu Chenghua.

Hi，Ruoyao:

The test of the 3a5000 will also be completed around the 15th of this month, so
I want to change the code after the test results of the 3a5000 are out.
What do you think?(In reply to Xi Ruoyao from comment #9)
> (In reply to chenglulu from comment #8)
> > (In reply to Xi Ruoyao from comment #7)
> > > Any update? :)
> > 
> > Well, I haven't run it yet. Since this does not have a big impact on the
> > spec score, I am currently testing it on a single-channel machine, so the
> > test time will be longer.
> > I will reply here as soon as the results are available.
> 
> Can we determine on LA664 if the current default alignment is better than
> not aligning at all?  Coremarks results suggest the current default is even
> worse than not aligning, but arguably Coremarks is far different from real
> workloads. However if the current default is not better than not aligning
> (or the difference is only marginal and is likely covered up by some random
> fluctuation) we can disable the aligning for LA664.

Hi，Ruoyao:

 The results of spec2006 on 3A6000 were obtained, I removed the more volatile
test items, '-falign-loops=8 -falign-functions=8 -falign-jumps=32
-falign-lables=4' this set of parameters got the highest score. This is the
same combination of parameters as the coremark tested by Xu Chenghua.

The test of the 3A5000 will also be completed around the 15th of this month, so
I want to change the code after the test results of the 3a5000 are out.
What do you think?