From c2e08db4e5a8e1b3c253fb07c6eb736dfb66fe59 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Fri, 17 Feb 2012 00:27:16 +0000
Subject: [PATCH] Re-enable 150652 and 150654 - Make FPSCR non-reserved, and
 make MachineCSE bail on reserved registers. This *should* be safe as of
 r150786.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150769 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/MachineCSE.cpp             | 12 +++++++++---
 lib/Target/ARM/ARMBaseRegisterInfo.cpp |  1 -
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 3031d4588b2..491a22caf0c 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/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/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 6a46e636267..9c8486c9bcd 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/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))
-- 
2.34.1