Commit 30179d7e authored by Johannes Doerfert's avatar Johannes Doerfert
Browse files

[Attributor][FIX][Alignment] Do not report a change if there was none 

If alignment was manifested but it is actually only as good as the
data-layout provided one we should not report it as a change.

For testing purposes we still manifest the information.
parent e273ac4d

llvm/lib/Transforms/IPO/Attributor.cpp

+16 −5
Original line number Diff line number Diff line
@@ -3474,7 +3474,7 @@ struct AAAlignImpl : AAAlign { 


  /// See AbstractAttribute::manifest(...).

  ChangeStatus manifest(Attributor &A) override {

    ChangeStatus Changed = ChangeStatus::UNCHANGED;

    ChangeStatus LoadStoreChanged = ChangeStatus::UNCHANGED;



    // Check for users that allow alignment annotations.

    Value &AnchorVal = getIRPosition().getAnchorValue();
@@ -3485,7 +3485,7 @@ struct AAAlignImpl : AAAlign { 
            STATS_DECLTRACK(AAAlign, Store,

                            "Number of times alignment added to a store");

            SI->setAlignment(Align(getAssumedAlign()));

            Changed = ChangeStatus::CHANGED;

            LoadStoreChanged = ChangeStatus::CHANGED;

          }

      } else if (auto *LI = dyn_cast<LoadInst>(U.getUser())) {

        if (LI->getPointerOperand() == &AnchorVal)
@@ -3493,12 +3493,18 @@ struct AAAlignImpl : AAAlign { 
            LI->setAlignment(Align(getAssumedAlign()));

            STATS_DECLTRACK(AAAlign, Load,

                            "Number of times alignment added to a load");

            Changed = ChangeStatus::CHANGED;

            LoadStoreChanged = ChangeStatus::CHANGED;

          }

      }

    }



    return AAAlign::manifest(A) | Changed;

    ChangeStatus Changed = AAAlign::manifest(A);



    MaybeAlign InheritAlign =

        getAssociatedValue().getPointerAlignment(A.getDataLayout());

    if (InheritAlign.valueOrOne() >= getAssumedAlign())

      return LoadStoreChanged;

    return Changed | LoadStoreChanged;

  }



  // TODO: Provide a helper to determine the implied ABI alignment and check in
@@ -3602,7 +3608,12 @@ struct AAAlignCallSiteArgument final : AAAlignFloating { 


  /// See AbstractAttribute::manifest(...).

  ChangeStatus manifest(Attributor &A) override {

    return AAAlignImpl::manifest(A);

    ChangeStatus Changed = AAAlignImpl::manifest(A);

    MaybeAlign InheritAlign =

        getAssociatedValue().getPointerAlignment(A.getDataLayout());

    if (InheritAlign.valueOrOne() >= getAssumedAlign())

      Changed = ChangeStatus::UNCHANGED;

    return Changed;

  }



  /// See AbstractAttribute::updateImpl(Attributor &A).