Displaying 2 results from an estimated 2 matches for "cval_verifi".
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cval_verify
2017 Jan 13
4
Wrong code bug after GVN/PRE?
Hi,
I've stumbled upon a case where I think gvn does a bad (wrong)
optimization. It's a bit messy to debug though so I'm not sure if I
should just write a PR about it a let someone who knows the code look at
it instead.
Anyway, for the bug to trigger I need to run the following passes in the
same opt invocation:
-sroa -instcombine -simplifycfg -instcombine -gvn
The problem
2017 Jan 13
2
Wrong code bug after GVN/PRE?
Yeah, there's a lot of things this could be.
On the memdep side:
Note that memdep is not actually properly updated in all cases by most
passes that claim to not invalidate it (they don't invalidate dependent
pointers, only pointers they directly touch).
There's already a bug filed about this. So far we've only seen missed-opt,
not wrong code from this.
But it should be possible