Revert r85346 change to control tail merging by CodeGenOpt::Level.

[oota-llvm.git] / lib / CodeGen / MachineRegisterInfo.cpp

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 544d83a33f7f9316325ce97b02ff79b90052a126..b31973e04fd9fdeb52ca59011f8d8f7162a2803a 100644 (file)
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -110,11 +110,9 @@ void MachineRegisterInfo::replaceRegWith(unsigned FromReg, unsigned ToReg) {
 MachineInstr *MachineRegisterInfo::getVRegDef(unsigned Reg) const {
   assert(Reg-TargetRegisterInfo::FirstVirtualRegister < VRegInfo.size() &&
          "Invalid vreg!");
-  for (reg_iterator I = reg_begin(Reg), E = reg_end(); I != E; ++I) {
-    // Since we are in SSA form, we can stop at the first definition.
-    if (I.getOperand().isDef())
-      return &*I;
-  }
+  // Since we are in SSA form, we can use the first definition.
+  if (!def_empty(Reg))
+    return &*def_begin(Reg);
   return 0;
 }