Re: [RFC] Contributing tree-ssa to mainline

[Jan Hubicka <hubicka at ucw dot cz>]

> > 3.  Deletions of superceded RTL optimization passes which would make
> >     GCC faster.
> > 
> Again, in progress.  I should add that even though we haven't yet
> removed RTL passes, things like bootstrap times are only 2% slower on
> the branch.  More work is needed in this area and in reducing memory
> consumption.  This could be considered a blocker.

We already elliminated tailcall pass.

I have patches to kill ADDRESSOF scheme and it only waits for the patch
concerning aliasing of arrays to be rewieved.

Zdenek has patch to elliminate loop header duplication that is AFAIK
also just waiting for approval.

Loop optimizer is being worked on.

There are other easy targets - NULL pointer ellimination for instance
that I was discussing with Jeff.

With the RTL expansion patch and loop optimizer we can elliminate need
for RTL branch prediction and profiling passes, tought I want to keep
the second in the tree to allow sanity checking of profile updating code
as discused earlier.

So even tought we won't easilly elliminate CSE, GCSE and one of 3 passes
of jump threading, many of other cases are already here.

I would also like to kill RTL BUILTIN_CONSTANT_P construct RSN.

Honza