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Re: IPA merge: Make salias work after SSA form was built


On 12/29/06, Jan Hubicka <jh@suse.cz> wrote:
> Okay, but:

Hi,
thank you for review! Unfortunately I found that it still fails on
verify_ssa on some pass orders on IPA-SSA. The problem is that we still
cache values in addresses_taken bitmap and trust them to be up to date.
This didn't reproduced in my original testing just because I had my
experimental "kill unnecesary datastructures" pass just before the
salias so the bitmaps was all clear at that point.  I don't intend to
submit that pass for mainline, it is basically just an experiment to see
how much memory we waste by caching things, so I would like to fix this
problem too.

Amusingly I didn't found any way to rebuild this bitmap after modifying
statement since tree-ssa-operand just compute it, but never clear the old
values.  Perhaps there is some way to recompute it correctly but at least it
is what I would expect update_stmt to do, so I updated build_ssa_operands
accordingly.

Bootstrapped/regtested i686-linux
OK? (and sorry for duplicated submision)

No problem at all. This is okay by me. Honestly, i'm a bit worried why we are caching addresses_taken at all anyway.

It seems to be a time/memory sink just so we can use it in *one* place
where we have just finished walking all the operands anyway.


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