[Bug middle-end/39326] Segmentation fault with -O1, out of memory with -O2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39326

--- Comment #40 from Richard Biener <rguenth at gcc dot gnu.org> 2013-03-08 09:12:38 UTC ---
(In reply to comment #31)
> (In reply to comment #30)
> Hmm, RTL PRE isn't really mine either, but I probably know it as well as
> anyone else, so I will have a look. It's probably a similar issue as for
> gimple LIM: alias checks.
> 
> Can you attach your TLC patches for gimple LIM to this PR, please?

Found it on some testing machine.  I merged it and saw to it that it
compiles and passes tree-ssa.exp (some ???s remain, I've added a TODO).
The idea should be clear, and it's memory savings only and it will eventually
be a bit slower (unless it is optimized further).