diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 7e8e416..5cec9e9 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -61,6 +61,14 @@
     return frameIndex;
 }
 
+void VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int frameIndex)
+{
+    assert(MRegisterInfo::isVirtualRegister(virtReg));
+    assert(v2ssMap_[virtReg] == NO_STACK_SLOT &&
+           "attempt to assign stack slot to already spilled register");
+     v2ssMap_[virtReg] = frameIndex;
+}
+
 void VirtRegMap::virtFolded(unsigned virtReg,
                             MachineInstr* oldMI,
                             MachineInstr* newMI)
diff --git a/lib/CodeGen/VirtRegMap.h b/lib/CodeGen/VirtRegMap.h
index c4188bc..e9bfe76 100644
--- a/lib/CodeGen/VirtRegMap.h
+++ b/lib/CodeGen/VirtRegMap.h
@@ -97,6 +97,7 @@
         }
 
         int assignVirt2StackSlot(unsigned virtReg);
+        void assignVirt2StackSlot(unsigned virtReg, int frameIndex);
 
         void virtFolded(unsigned virtReg,
                         MachineInstr* oldMI,