[PATCH] D82072: [InstCombine] Combine select & Phi by same condition

[Nikita Popov via Phabricator via llvm-commits]

nikic accepted this revision.
nikic added a comment.
This revision is now accepted and ready to land.

LGTM with test additions.



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Comment at: llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp:2486
     if (auto *Insn = dyn_cast<Instruction>(Inputs[Pred]))
       if (!DT.dominates(Insn, Pred->getTerminator()))
         return nullptr;
----------------
nikic wrote:
> We should add `&& Insn != Pred->getTerminator()` here to make the `@test_invoke_2_neg` test case work. What we really want to express is that `DT.dominates(Insn, Incoming)`, but as there is no `dominates(Instruction *, BasicBlockEdge)` API, this would be the closest replacement. (We could also add that API of course).
Actually, let's leave this to a separate patch. We should really do this via a DominatorTree API that can distinguish normal&unwind edges properly.


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https://reviews.llvm.org/D82072