[Bug tree-optimization/28778] [4.0/4.1/4.2 Regression] alias bug with cast and call clobbered

[mmitchel at gcc dot gnu dot org]

------- Comment #26 from mmitchel at gcc dot gnu dot org  2006-08-27 20:28 -------
I don't understand how TBAA is interacting with the may-alias information.

In particular, TBAA doesn't say anything about casts; it says something about
loads and stores.  In particular, TBAA forbids accessing storage of type A
through a pointer to type B, given certain constraints on A and B.  It does not
forbid casting an A* to a B*.

Why are the optimizers pruning may-alias sets on casts?  Why isn't the fix just
to stop them from doing that?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28778