On Tue, 12 Sep 2017, Jakub Jelinek wrote:
> On Tue, Sep 12, 2017 at 04:09:41PM +0200, Richard Biener wrote:
> >
> > The following "fixes" PR82129 (hides the issue). It folds
> > writes from uninitialized data to CLOBBERs:
> >
> > - *h5_26(D) = tv_24(D);
> > + *h5_26(D) ={v} {CLOBBER};
> >
> > Bootstrap & regtest running on x86_64-unknown-linux-gnu.
>
> Won't that affect -W{,maybe-}unitialized a lot?
Not sure - as current it fails bootstrap because I need to guard
against not folding things like foo.bar = x_2(D) (we assert to
have clobbers only on full objects).
Richard.
> > 2017-09-12 Richard Biener <[email protected]>
> >
> > PR tree-optimization/82129
> > * gimple-fold.c (fold_gimple_assign): Fold stores from undefined
> > values to clobbers.
> >
> > * gcc.dg/torture/pr82129.c: New testcase.
