[llvm-commits] [llvm] r150653 - /llvm/trunk/lib/CodeGen/MachineCSE.cpp

[Lang Hames]

Author: lhames
Date: Wed Feb 15 20:19:35 2012
New Revision: 150653

URL: http://llvm.org/viewvc/llvm-project?rev=150653&view=rev
Log:
MachineCSE shouldn't extend the live ranges of reserved or allocatable registers.

Modified:
    llvm/trunk/lib/CodeGen/MachineCSE.cpp

Modified: llvm/trunk/lib/CodeGen/MachineCSE.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineCSE.cpp?rev=150653&r1=150652&r2=150653&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineCSE.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineCSE.cpp Wed Feb 15 20:19:35 2012
@@ -63,6 +63,8 @@
     virtual void releaseMemory() {
       ScopeMap.clear();
       Exps.clear();
+      AllocatableRegs.clear();
+      ReservedRegs.clear();
     }
 
   private:
@@ -76,6 +78,8 @@
     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 @@
       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 @@
   MRI = &MF.getRegInfo();
   AA = &getAnalysis<AliasAnalysis>();
   DT = &getAnalysis<MachineDominatorTree>();
+  AllocatableRegs = TRI->getAllocatableSet(MF);
+  ReservedRegs = TRI->getReservedRegs(MF);
   return PerformCSE(DT->getRootNode());
 }