1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
index 4c16ae70d1f..26c2a20dea1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
@@ -93,6 +93,12 @@ void DwarfExpression::AddMachineRegPiece(unsigned MachineReg,
                                          unsigned PieceSizeInBits,
                                          unsigned PieceOffsetInBits) {
   const TargetRegisterInfo *TRI = getTRI();
+  if (!TRI->isPhysicalRegister(MachineReg)) {
+    // FIXME: We have no reasonable way of handling errors in here.
+    EmitOp(dwarf::DW_OP_nop, "nop (could not find a dwarf register number)");
+    return;
+  }
+
   int Reg = TRI->getDwarfRegNum(MachineReg, false);
 
   // If this is a valid register number, emit it.