https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104475
Aldy Hernandez <aldyh at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |law at gcc dot gnu.org
--- Comment #8 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #7)
> I think we shouldn't do anything on the optimization side - sure, the path
> isolation in the end turns out not profitable, but it's likely hard to decide
> that.
>
> Maybe we can somehow avoid threading for a ptr == 0 condition? Why do we
> make
> the threading profitable?
The threaders are mostly blind wrt threading a path. If they see it, they will
thread it. There are some minor things we disallow (see calls to cancel_thread
throughout) and the big hammer we introduced in this release with
cancel_invalid_paths() where we disallow problematic loop transformations. But
mostly we thread everything that's possible.
Disallowing ptr == 0 as well as highly unlikely paths should be trivial. We
could add a simple check in cancel_invalid_paths(). Though, I assume that would
affect warning code all over, since we're reducing the amount of threadable
paths on which they depend?
