1 files changed, 15 insertions, 0 deletions
diff --git a/lib/CodeGen/VirtRegMap.h b/lib/CodeGen/VirtRegMap.h
index 6f82cfb62c..46f177d4f5 100644
--- a/lib/CodeGen/VirtRegMap.h
+++ b/lib/CodeGen/VirtRegMap.h
@@ -18,6 +18,7 @@
 #define LLVM_CODEGEN_VIRTREGMAP_H
 
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/IndexedMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -116,6 +117,10 @@ namespace llvm {
     /// SpillSlotToUsesMap - Records uses for each register spill slot.
     SmallVector<SmallPtrSet<MachineInstr*, 4>, 8> SpillSlotToUsesMap;
 
+    /// ImplicitDefed - One bit for each virtual register. If set it indicates
+    /// the register is implicitly defined.
+    BitVector ImplicitDefed;
+
     VirtRegMap(const VirtRegMap&);     // DO NOT IMPLEMENT
     void operator=(const VirtRegMap&); // DO NOT IMPLEMENT
 
@@ -382,6 +387,16 @@ namespace llvm {
       return !SpillSlotToUsesMap[FrameIndex-LowSpillSlot].empty();
     }
 
+    /// @brief Mark the specified register as being implicitly defined.
+    void setIsImplicitlyDefined(unsigned VirtReg) {
+      ImplicitDefed.set(VirtReg-TargetRegisterInfo::FirstVirtualRegister);
+    }
+
+    /// @brief Returns true if the virtual register is implicitly defined.
+    bool isImplicitlyDefined(unsigned VirtReg) const {
+      return ImplicitDefed[VirtReg-TargetRegisterInfo::FirstVirtualRegister];
+    }
+
     /// @brief Updates information about the specified virtual register's value
     /// folded into newMI machine instruction.
     void virtFolded(unsigned VirtReg, MachineInstr *OldMI, MachineInstr *NewMI,