diff --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 664bfe7a9c0f..faae9b2f22ae 100644
--- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -172,12 +172,13 @@ void PPCDAGToDAGISel::InsertVRSaveCode(MachineFunction &Fn) {
   // In this case, there will be virtual registers of vector type created
   // by the scheduler.  Detect them now.
   bool HasVectorVReg = false;
-  for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
-       e = RegInfo->getLastVirtReg()+1; i != e; ++i)
-    if (RegInfo->getRegClass(i) == &PPC::VRRCRegClass) {
+  for (unsigned i = 0, e = RegInfo->getNumVirtRegs(); i != e; ++i) {
+    unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
+    if (RegInfo->getRegClass(Reg) == &PPC::VRRCRegClass) {
       HasVectorVReg = true;
       break;
     }
+  }
   if (!HasVectorVReg) return;  // nothing to do.
 
   // If we have a vector register, we want to emit code into the entry and exit
diff --git a/llvm/lib/Target/X86/X86RegisterInfo.cpp b/llvm/lib/Target/X86/X86RegisterInfo.cpp
index 1844b2a9810f..ce4966dfdc7f 100644
--- a/llvm/lib/Target/X86/X86RegisterInfo.cpp
+++ b/llvm/lib/Target/X86/X86RegisterInfo.cpp
@@ -814,13 +814,13 @@ namespace {
       // Be over-conservative: scan over all vreg defs and find whether vector
       // registers are used. If yes, there is a possibility that vector register
       // will be spilled and thus require dynamic stack realignment.
-      for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
-           RegNum < RI.getLastVirtReg(); ++RegNum)
-        if (RI.getRegClass(RegNum)->getAlignment() > StackAlignment) {
+      for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
+        unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
+        if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
           FuncInfo->setReserveFP(true);
           return true;
         }
-
+      }
       // Nothing to do
       return false;
     }