X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FCodeGen%2FRegisterScavenging.h;h=3986a8dd7da15713efa2aa81b75534deb8c73230;hb=412cd2f81374865dfa708bef6d5b896ca10dece0;hp=6a15fcf065925cb3dca45a5fcf2890426307cae8;hpb=66a39699fb6b862e674415b32d307263812e996e;p=oota-llvm.git

diff --git a/include/llvm/CodeGen/RegisterScavenging.h b/include/llvm/CodeGen/RegisterScavenging.h
index 6a15fcf0659..3986a8dd7da 100644
--- a/include/llvm/CodeGen/RegisterScavenging.h
+++ b/include/llvm/CodeGen/RegisterScavenging.h
@@ -68,6 +68,10 @@ class RegScavenger {
   /// available, unset means the register is currently being used.
   BitVector RegsAvailable;
 
+  // These BitVectors are only used internally to forward(). They are members
+  // to avoid frequent reallocations.
+  BitVector KillRegs, DefRegs;
+
 public:
   RegScavenger()
     : MBB(NULL), NumPhysRegs(0), Tracking(false),
@@ -98,15 +102,13 @@ public:
   /// getRegsUsed - return all registers currently in use in used.
   void getRegsUsed(BitVector &used, bool includeReserved);
 
-  /// FindUnusedReg - Find a unused register of the specified register class
-  /// from the specified set of registers. It return 0 is none is found.
-  unsigned FindUnusedReg(const TargetRegisterClass *RegClass,
-                         const BitVector &Candidates) const;
+  /// getRegsAvailable - Return all available registers in the register class
+  /// in Mask.
+  BitVector getRegsAvailable(const TargetRegisterClass *RC);
 
   /// FindUnusedReg - Find a unused register of the specified register class.
-  /// Exclude callee saved registers if directed. It return 0 is none is found.
-  unsigned FindUnusedReg(const TargetRegisterClass *RegClass,
-                         bool ExCalleeSaved = false) const;
+  /// Return 0 if none is found.
+  unsigned FindUnusedReg(const TargetRegisterClass *RegClass) const;
 
   /// setScavengingFrameIndex / getScavengingFrameIndex - accessor and setter of
   /// ScavengingFrameIndex.
@@ -123,23 +125,26 @@ public:
     return scavengeRegister(RegClass, MBBI, SPAdj);
   }
 
+  /// setUsed - Tell the scavenger a register is used.
+  ///
+  void setUsed(unsigned Reg);
 private:
   /// isReserved - Returns true if a register is reserved. It is never "unused".
   bool isReserved(unsigned Reg) const { return ReservedRegs.test(Reg); }
 
-  /// isUsed / isUsed - Test if a register is currently being used.
+  /// isUsed / isUnused - Test if a register is currently being used.
   ///
-  bool isUsed(unsigned Reg) const   { return !RegsAvailable.test(Reg); }
-  bool isUnused(unsigned Reg) const { return RegsAvailable.test(Reg); }
+  bool isUsed(unsigned Reg) const   {
+    return !RegsAvailable.test(Reg) || ReservedRegs.test(Reg);
+  }
 
   /// isAliasUsed - Is Reg or an alias currently in use?
   bool isAliasUsed(unsigned Reg) const;
 
   /// setUsed / setUnused - Mark the state of one or a number of registers.
   ///
-  void setUsed(unsigned Reg);
   void setUsed(BitVector &Regs) {
-    RegsAvailable &= ~Regs;
+    RegsAvailable.reset(Regs);
   }
   void setUnused(BitVector &Regs) {
     RegsAvailable |= Regs;
@@ -148,10 +153,12 @@ private:
   /// Add Reg and all its sub-registers to BV.
   void addRegWithSubRegs(BitVector &BV, unsigned Reg);
 
-  /// Add Reg and its aliases to BV.
-  void addRegWithAliases(BitVector &BV, unsigned Reg);
-
-  unsigned findSurvivorReg(MachineBasicBlock::iterator MI,
+  /// findSurvivorReg - Return the candidate register that is unused for the
+  /// longest after StartMI. UseMI is set to the instruction where the search
+  /// stopped.
+  ///
+  /// No more than InstrLimit instructions are inspected.
+  unsigned findSurvivorReg(MachineBasicBlock::iterator StartMI,
                            BitVector &Candidates,
                            unsigned InstrLimit,
                            MachineBasicBlock::iterator &UseMI);