3 files changed, 7 insertions, 12 deletions
diff --git a/llvm/lib/CodeGen/Analysis.cpp b/llvm/lib/CodeGen/Analysis.cpp
index 7c1fb6879a6..b769e92590f 100644
--- a/llvm/lib/CodeGen/Analysis.cpp
+++ b/llvm/lib/CodeGen/Analysis.cpp
@@ -519,10 +519,12 @@ bool llvm::attributesPermitTailCall(const Function *F, const Instruction *I,
   AttrBuilder CalleeAttrs(cast<CallInst>(I)->getAttributes(),
                           AttributeList::ReturnIndex);
 
-  // Noalias is completely benign as far as calling convention goes, it
-  // shouldn't affect whether the call is a tail call.
+  // NoAlias and NonNull are completely benign as far as calling convention
+  // goes, they shouldn't affect whether the call is a tail call.
   CallerAttrs.removeAttribute(Attribute::NoAlias);
   CalleeAttrs.removeAttribute(Attribute::NoAlias);
+  CallerAttrs.removeAttribute(Attribute::NonNull);
+  CalleeAttrs.removeAttribute(Attribute::NonNull);
 
   if (CallerAttrs.contains(Attribute::ZExt)) {
     if (!CalleeAttrs.contains(Attribute::ZExt))
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index ec4451ffa75..d69e9589976 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -1871,15 +1871,6 @@ bool CodeGenPrepare::dupRetToEnableTailCallOpts(BasicBlock *BB) {
     CallInst *CI = TailCalls[i];
     CallSite CS(CI);
 
-    // Conservatively require the attributes of the call to match those of the
-    // return. Ignore noalias because it doesn't affect the call sequence.
-    AttributeList CalleeAttrs = CS.getAttributes();
-    if (AttrBuilder(CalleeAttrs, AttributeList::ReturnIndex)
-            .removeAttribute(Attribute::NoAlias) !=
-        AttrBuilder(CalleeAttrs, AttributeList::ReturnIndex)
-            .removeAttribute(Attribute::NoAlias))
-      continue;
-
     // Make sure the call instruction is followed by an unconditional branch to
     // the return block.
     BasicBlock *CallBB = CI->getParent();
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index d7d4bef8d3c..46c2f8ebfb8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -55,10 +55,12 @@ bool TargetLowering::isInTailCallPosition(SelectionDAG &DAG, SDNode *Node,
   const Function &F = DAG.getMachineFunction().getFunction();
 
   // Conservatively require the attributes of the call to match those of
-  // the return. Ignore noalias because it doesn't affect the call sequence.
+  // the return. Ignore NoAlias and NonNull because they don't affect the
+  // call sequence.
   AttributeList CallerAttrs = F.getAttributes();
   if (AttrBuilder(CallerAttrs, AttributeList::ReturnIndex)
           .removeAttribute(Attribute::NoAlias)
+          .removeAttribute(Attribute::NonNull)
           .hasAttributes())
     return false;