2 files changed, 9 insertions, 3 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index f97edb4ef09..13b097cfc60 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1569,8 +1569,10 @@ bool FastISel::selectOperator(const User *I, unsigned Opcode) {
   }
 
   case Instruction::Unreachable:
-    // Nothing to emit.
-    return true;
+    if (TM.Options.TrapUnreachable)
+      return fastEmit_(MVT::Other, MVT::Other, ISD::TRAP) != 0;
+    else
+      return true;
 
   case Instruction::Alloca:
     // FunctionLowering has the static-sized case covered.
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 9371944d242..9e315194c98 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2260,7 +2260,11 @@ void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) {
                           getValue(I.getAddress())));
 }
 
-void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {}
+void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {
+  if (DAG.getTarget().Options.TrapUnreachable)
+    DAG.setRoot(
+        DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
+}
 
 void SelectionDAGBuilder::visitFSub(const User &I) {
   // -0.0 - X --> fneg