Commit 9dcf889d authored by Johannes Doerfert's avatar Johannes Doerfert
Browse files

[Attributor][NFC] Do not (try to) simplify void values 

We might accidentally ask AAValueSimplify to simplify a void value. That
can lead to very interesting, and very wrong, results. We now handle
this case gracefully.
parent 47d7a81b

llvm/lib/Transforms/IPO/Attributor.cpp

+6 −1
Original line number Diff line number Diff line
@@ -4131,6 +4131,12 @@ struct AANoCaptureCallSiteReturned final : AANoCaptureImpl { 
struct AAValueSimplifyImpl : AAValueSimplify {

  AAValueSimplifyImpl(const IRPosition &IRP) : AAValueSimplify(IRP) {}



  /// See AbstractAttribute::initialize(...).

  void initialize(Attributor &A) override {

    if (getAssociatedValue().getType()->isVoidTy())

      indicatePessimisticFixpoint();

  }



  /// See AbstractAttribute::getAsStr().

  const std::string getAsStr() const override {

    return getAssumed() ? (getKnown() ? "simplified" : "maybe-simple")
@@ -4146,7 +4152,6 @@ struct AAValueSimplifyImpl : AAValueSimplify { 
      return const_cast<Value *>(&getAssociatedValue());

    return SimplifiedAssociatedValue;

  }

  void initialize(Attributor &A) override {}



  /// Helper function for querying AAValueSimplify and updating candicate.

  /// \param QueryingValue Value trying to unify with SimplifiedValue