1 files changed, 20 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index e5148e74be8..4f5ab1f5860 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -35,6 +35,26 @@ MachineRegisterInfo::~MachineRegisterInfo() {
   delete [] PhysRegUseDefLists;
 }
 
+/// setRegClass - Set the register class of the specified virtual register.
+///
+void
+MachineRegisterInfo::setRegClass(unsigned Reg, const TargetRegisterClass *RC) {
+  unsigned VR = Reg;
+  Reg -= TargetRegisterInfo::FirstVirtualRegister;
+  assert(Reg < VRegInfo.size() && "Invalid vreg!");
+  const TargetRegisterClass *OldRC = VRegInfo[Reg].first;
+  VRegInfo[Reg].first = RC;
+
+  // Remove from old register class's vregs list. This may be slow but
+  // fortunately this operation is rarely needed.
+  std::vector<unsigned> &VRegs = RegClass2VRegMap[OldRC->getID()];
+  std::vector<unsigned>::iterator I=std::find(VRegs.begin(), VRegs.end(), VR);
+  VRegs.erase(I);
+
+  // Add to new register class's vregs list.
+  RegClass2VRegMap[RC->getID()].push_back(VR);
+}
+
 /// createVirtualRegister - Create and return a new virtual register in the
 /// function with the specified register class.
 ///