/// Lower PHI instructions to copies.
class PHIElimination : public MachineFunctionPass {
MachineRegisterInfo *MRI; // Machine register information
- typedef DenseMap<unsigned, MachineBasicBlock*> PHIDefMap;
public:
-
static char ID; // Pass identification, replacement for typeid
PHIElimination() : MachineFunctionPass(&ID) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- /// Return true if the given vreg was defined by a PHI intsr prior to
- /// lowering.
- bool hasPHIDef(unsigned vreg) const {
- return PHIDefs.count(vreg);
- }
-
private:
/// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions
/// in predecessor basic blocks.
typedef DenseMap<BBVRegPair, unsigned> VRegPHIUse;
VRegPHIUse VRegPHIUseCount;
- PHIDefMap PHIDefs;
// Defs of PHI sources which are implicit_def.
SmallPtrSet<MachineInstr*, 4> ImpDefs;
- // Lowered PHI nodes may be reused. We provide special DenseMap traits to
- // match PHI nodes with identical arguments.
- struct PHINodeTraits : public DenseMapInfo<MachineInstr*> {
- static unsigned getHashValue(const MachineInstr *PtrVal);
- static bool isEqual(const MachineInstr *LHS, const MachineInstr *RHS);
- };
-
// Map reusable lowered PHI node -> incoming join register.
- typedef DenseMap<MachineInstr*, unsigned, PHINodeTraits> LoweredPHIMap;
+ typedef DenseMap<MachineInstr*, unsigned,
+ MachineInstrExpressionTrait> LoweredPHIMap;
LoweredPHIMap LoweredPHIs;
};