diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -8369,9 +8369,9 @@
     return;
   }
 
-  if (Function *F = I.getCalledFunction()) {
-    diagnoseDontCall(I);
+  diagnoseDontCall(I);
 
+  if (Function *F = I.getCalledFunction()) {
     if (F->isDeclaration()) {
       // Is this an LLVM intrinsic or a target-specific intrinsic?
       unsigned IID = F->getIntrinsicID();
diff --git a/llvm/lib/IR/DiagnosticInfo.cpp b/llvm/lib/IR/DiagnosticInfo.cpp
--- a/llvm/lib/IR/DiagnosticInfo.cpp
+++ b/llvm/lib/IR/DiagnosticInfo.cpp
@@ -416,7 +416,9 @@
 void OptimizationRemarkAnalysisAliasing::anchor() {}
 
 void llvm::diagnoseDontCall(const CallInst &CI) {
-  auto *F = CI.getCalledFunction();
+  const auto *F =
+      dyn_cast<Function>(CI.getCalledOperand()->stripPointerCasts());
+
   if (!F)
     return;
 
diff --git a/llvm/test/CodeGen/X86/attr-dontcall.ll b/llvm/test/CodeGen/X86/attr-dontcall.ll
--- a/llvm/test/CodeGen/X86/attr-dontcall.ll
+++ b/llvm/test/CodeGen/X86/attr-dontcall.ll
@@ -20,6 +20,14 @@
   ret void
 }
 
+declare void @foo4(i32) addrspace(1) "dontcall-warn"="cast"
+
+define void @bar4() {
+  call void addrspacecast (ptr addrspace(1) @foo4 to ptr)(i32 0)
+  ret void
+}
+
 ; CHECK: error: call to foo marked "dontcall-error": e
 ; CHECK: warning: call to foo2 marked "dontcall-warn": w
 ; CHECK: warning: call to foo3 marked "dontcall-warn"{{$}}
+; CHECK: warning: call to foo4 marked "dontcall-warn": cast