[PATCH] D88207: [ValueTracking] Check uses of Argument if it is given to isGuaranteedNotToBeUndefOrPoison

[Juneyoung Lee via Phabricator via llvm-commits]

aqjune added inline comments.


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:5165
+  if (!isa<Argument>(V) && !isa<Instruction>(V))
+    return false;
+
----------------
aqjune wrote:
> nikic wrote:
> > nikic wrote:
> > > aqjune wrote:
> > > > Unit tests say V can be MetadataAsValue as well (that is called from AANoUndefImpl::initialize).
> > > > But, does it imply that AANoUndefImpl::initialize should be fixed?
> > > I think it would be more elegant to write
> > > ```
> > > } else if (auto *Arg = dyn_cast<Argument>(V)) {
> > >    // ...
> > > } else {
> > >    return false;
> > > }
> > > ```
> > > below, rather than having having to keep the checks here and below in sync.
> > > Unit tests say V can be MetadataAsValue as well (that is called from AANoUndefImpl::initialize).
> > > But, does it imply that AANoUndefImpl::initialize should be fixed?
> > 
> > I don't think there's anything wrong with. It shouldn't cause issues for this code as implemented, right?
> It happened because there was a function call that had a metadata as its argument, and AANoUndefImpl was somehow trying to work with the metadata argument.
> Yes, I think AANoUndefImpl is okay. I feel it might be safe for isGuaranteedNotToBeUndefOrPoison to simply return false when MetadataAsValue is given, to make possible future changes assertion-safe.
Made the change at https://github.com/llvm/llvm-project/commit/92106641ae297c24877085e0357e8095aa7b43c9 as a NFC commit, because it's just a couple of lines change


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  https://reviews.llvm.org/D88207/new/

https://reviews.llvm.org/D88207