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Re: [tree-ssa]: GIMPLE lowering array references too early?
- From: Chris Lattner <sabre at nondot dot org>
- To: law at redhat dot com
- Cc: Daniel Berlin <dberlin at dberlin dot org>, <gcc at gcc dot gnu dot org>,<jason at redhat dot com>, <dnovillo at redhat dot com>
- Date: Tue, 29 Jul 2003 13:14:34 -0500 (CDT)
- Subject: Re: [tree-ssa]: GIMPLE lowering array references too early?
On Tue, 29 Jul 2003 law@redhat.com wrote:
> >Would this break everything?
> It's a source of annoyance. I had started cobbling together some code to
> do this, but things kept breaking downstream. Probably due to my lack of
> knowledge about reform the ARRAY_REFs/ARRAY_TYPEs.
I have done a fair amount of work in the past trying to reconstruct array
references from "lowered" address arithmetic like this, and have come to
the conclusion that there is no good way to do it in general.
Given the right people working on the problem, and enough interest, do you
think it's possible to "fix it right" in the places that break downstream?
> I've seen real codes which suffer because of the inconsistencies in how
> we generate trees for array references depending on whether or not the
> underlying type is a pointer or an array.
It basically makes it impossible to perform loop optimizations on
non-trivial C loops... so yes, it definately does!
-Chris
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