2 files changed, 9 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/MachineCSE.cpp b/llvm/lib/CodeGen/MachineCSE.cpp
index 3031d4588b2..491a22caf0c 100644
--- a/llvm/lib/CodeGen/MachineCSE.cpp
+++ b/llvm/lib/CodeGen/MachineCSE.cpp
@@ -63,6 +63,8 @@ namespace {
     virtual void releaseMemory() {
       ScopeMap.clear();
       Exps.clear();
+      AllocatableRegs.clear();
+      ReservedRegs.clear();
     }
 
   private:
@@ -76,6 +78,8 @@ namespace {
     ScopedHTType VNT;
     SmallVector<MachineInstr*, 64> Exps;
     unsigned CurrVN;
+    BitVector AllocatableRegs;
+    BitVector ReservedRegs;
 
     bool PerformTrivialCoalescing(MachineInstr *MI, MachineBasicBlock *MBB);
     bool isPhysDefTriviallyDead(unsigned Reg,
@@ -236,9 +240,9 @@ bool MachineCSE::PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
       return false;
 
     for (unsigned i = 0, e = PhysDefs.size(); i != e; ++i) {
-      if (TRI->isInAllocatableClass(PhysDefs[i]))
-        // Avoid extending live range of physical registers unless
-        // they are unallocatable.
+      if (AllocatableRegs.test(PhysDefs[i]) || ReservedRegs.test(PhysDefs[i]))
+        // Avoid extending live range of physical registers if they are
+        //allocatable or reserved.
         return false;
     }
     CrossMBB = true;
@@ -588,5 +592,7 @@ bool MachineCSE::runOnMachineFunction(MachineFunction &MF) {
   MRI = &MF.getRegInfo();
   AA = &getAnalysis<AliasAnalysis>();
   DT = &getAnalysis<MachineDominatorTree>();
+  AllocatableRegs = TRI->getAllocatableSet(MF);
+  ReservedRegs = TRI->getReservedRegs(MF);
   return PerformCSE(DT->getRootNode());
 }
diff --git a/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 6a46e636267..9c8486c9bcd 100644
--- a/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -79,7 +79,6 @@ getReservedRegs(const MachineFunction &MF) const {
   BitVector Reserved(getNumRegs());
   Reserved.set(ARM::SP);
   Reserved.set(ARM::PC);
-  Reserved.set(ARM::FPSCR);
   if (TFI->hasFP(MF))
     Reserved.set(FramePtr);
   if (hasBasePointer(MF))