[Bug tree-optimization/60770] disappearing clobbers

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60770

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

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                 CC|                            |manu at gcc dot gnu.org

--- Comment #2 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Marc Glisse from comment #1)
> I guess relying on clobbers in the middle-end for warnings is a bit
> optimistic...

If I interpret the dump correctly, this is a valid optimization because the
original code is undefined, but it is hiding the fact that the original code is
buggy. CCP does this kind of thing for uninitialized warnings (PR18501), and it
would be nice to find a way to warn for it.