diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 3880283..1462472 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -210,6 +210,11 @@
       // Something more complicated. Halt "fast" selection and bail.
       return I;
     }
+
+    case Instruction::PHI:
+      // PHI nodes are already emitted.
+      break;
+
     default:
       // Unhandled instruction. Halt "fast" selection and bail.
       return I;