Subzero: Allow delaying Phi lowering until after register allocation.

src/IceTargetLoweringX8632.h

 //===- subzero/src/IceTargetLoweringX8632.h - x86-32 lowering ---*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the TargetLoweringX8632 class, which
@@ skipping 87 matching lines @@
   void lowerIcmp(const InstIcmp *Inst) override;
   void lowerIntrinsicCall(const InstIntrinsicCall *Inst) override;
   void lowerInsertElement(const InstInsertElement *Inst) override;
   void lowerLoad(const InstLoad *Inst) override;
   void lowerPhi(const InstPhi *Inst) override;
   void lowerRet(const InstRet *Inst) override;
   void lowerSelect(const InstSelect *Inst) override;
   void lowerStore(const InstStore *Inst) override;
   void lowerSwitch(const InstSwitch *Inst) override;
   void lowerUnreachable(const InstUnreachable *Inst) override;
+  void prelowerPhis() override;
+  void lowerPhiAssignments(CfgNode *Node,
+                           const AssignList &Assignments) override;
   void doAddressOptLoad() override;
   void doAddressOptStore() override;
   void randomlyInsertNop(float Probability) override;
 
   // Naive lowering of cmpxchg.
   void lowerAtomicCmpxchg(Variable *DestPrev, Operand *Ptr, Operand *Expected,
                           Operand *Desired);
   // Attempt a more optimized lowering of cmpxchg. Returns true if optimized.
   bool tryOptimizedCmpxchgCmpBr(Variable *DestPrev, Operand *Ptr,
                                 Operand *Expected, Operand *Desired);
@@ skipping 357 matching lines @@
   const X86InstructionSet InstructionSet;
   bool IsEbpBasedFrame;
   bool NeedsStackAlignment;
   size_t FrameSizeLocals;
   size_t SpillAreaSizeBytes;
   llvm::SmallBitVector TypeToRegisterSet[IceType_NUM];
   llvm::SmallBitVector ScratchRegs;
   llvm::SmallBitVector RegsUsed;
   SizeT NextLabelNumber;
   bool ComputedLiveRanges;
-  VarList PhysicalRegisters;
+  VarList PhysicalRegisters[IceType_NUM];
   static IceString RegNames[];
 
 private:
   ~TargetX8632() override {}
   template <typename T> void emitConstantPool() const;
 };
 
 class TargetGlobalInitX8632 : public TargetGlobalInitLowering {
   TargetGlobalInitX8632(const TargetGlobalInitX8632 &) = delete;
   TargetGlobalInitX8632 &operator=(const TargetGlobalInitX8632 &) = delete;
@@ skipping 13 matching lines @@
 };
 
 template <> void ConstantInteger32::emit(GlobalContext *Ctx) const;
 template <> void ConstantInteger64::emit(GlobalContext *Ctx) const;
 template <> void ConstantFloat::emit(GlobalContext *Ctx) const;
 template <> void ConstantDouble::emit(GlobalContext *Ctx) const;
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX8632_H