[Attributor] Remove dereferenceable_or_null when nonull is present

Summary: This patch prevents the simultaneous presence of `dereferenceable` and `dereferenceable_or_null` attribute

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: lebedev.ri, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70789

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index faf0cdfd08e..e73698620de 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -2971,6 +2971,16 @@ struct AADereferenceableImpl : AADereferenceable {
     return TrackUse;
   }
 
+  /// See AbstractAttribute::manifest(...).
+  ChangeStatus manifest(Attributor &A) override {
+    ChangeStatus Change = AADereferenceable::manifest(A);
+    if (isAssumedNonNull() && hasAttr(Attribute::DereferenceableOrNull)) {
+      removeAttrs({Attribute::DereferenceableOrNull});
+      return ChangeStatus::CHANGED;
+    }
+    return Change;
+  }
+
   void getDeducedAttributes(LLVMContext &Ctx,
                             SmallVectorImpl<Attribute> &Attrs) const override {
     // TODO: Add *_globally support