[PATCH] D99987: [NewGVN] Track simplification dependencies for phi-of-ops.

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/NewGVN.cpp:1874-1900
           if (CmpInst::isImpliedTrueByMatchingCmp(BranchPredicate,
                                                   OurPredicate)) {
             addPredicateUsers(PI, I);
             return createConstantExpression(
                 ConstantInt::getTrue(CI->getType()));
           }
 
----------------
fhahn wrote:
> ruiling wrote:
> > I think we also need to return the PI->Condition as ExtraDep together with the expression for such cases, this is what I saw in the case PR49873 that we failed to mark the 'real' instruction (i.e. op-of-phi) depends on this predicate compare.
> Thanks, I'll give that a try, but I think it's worth to do this as follow-up patch.
I updated `performSymbolicPredicateInfoEvaluation` in D100560 to use the same approach to register additional dependencies for the predicate simplification.


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https://reviews.llvm.org/D99987