diff --git a/llvm/lib/CodeGen/TailDuplicator.cpp b/llvm/lib/CodeGen/TailDuplicator.cpp
--- a/llvm/lib/CodeGen/TailDuplicator.cpp
+++ b/llvm/lib/CodeGen/TailDuplicator.cpp
@@ -627,6 +627,14 @@
     if (PreRegAlloc && MI.isCall())
       return false;
 
+    // Copying a block with an INLINEASM_BR instruction may result in a PHI node
+    // on the indirect path. We assume that all values used on the indirect path
+    // dominates all paths into the indirect block, i.e. don't have PHI nodes.
+    // FIXME: This may be too restrictive. Perhaps should restrict only if a
+    //        value in the current block isn't used on the indirect path.
+    if (MI.getOpcode() == TargetOpcode::INLINEASM_BR)
+      return false;
+
     if (MI.isBundle())
       InstrCount += MI.getBundleSize();
     else if (!MI.isPHI() && !MI.isMetaInstruction())