[tree-ssa] Preliminary analysis on POOMA slow downs (was Re: [tree-ssa] Speed up constant propagation)

[Steven Bosscher]

Daniel Berlin wrote:

>
> On Tuesday, June 17, 2003, at 01:07  PM, Diego Novillo wrote:
>
>>
>> I'm a bit surprised that the inliner is taking such a big hit.
>
>
>
> Hrmmmmm.
> Remember we downed INSNS_PER_STMT (tree-inline.c), which increases the 
> amount of inlining done.
> That was done only considering the effects of GIMPLE on C (and even 
> then, it was a while ago).
> It might need reevaluation in light of C++ gimplification, etc.

AFAICT it was never done and INSNS_PER_STMT is 10 on both mainline and 
branch.

It looks more like you suffer from the extra pointers from the tree 
iterators and from the extra tree copying because GIMPLE has more trees 
and unshares everything.

>
> Try setting it to 5 and see what happens.


Fewer insns per statement will only _increase_ the amount of inlining, 
so this may not be a good idea.

Gr.
Steven