Subzero: Refactor x86 register representation to actively use aliases.

src/IceTargetLoweringARM32.h

 //===- subzero/src/IceTargetLoweringARM32.h - ARM32 lowering ----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 30 matching lines @@
     HWDivArm, // HW divide in ARM mode (not just Thumb mode).
     End
   };
 
   bool hasFeature(ARM32InstructionSet I) const { return I <= InstructionSet; }
 
 private:
   ARM32InstructionSet InstructionSet = ARM32InstructionSet::Begin;
 };
 
+// Extend enum RegClass with ARM32-specific register classes (if any).
+enum RegClassARM32 : uint8_t { RCARM32_NUM = RC_Target };

[John, 2015/11/09 16:23:29]

This belongs in the IceRegistersARM32.h file, right?

[Jim Stichnoth, 2015/11/09 18:45:35]

Done (for MIPS too).

+
 // The target lowering logic for ARM32.
 class TargetARM32 : public TargetLowering {
   TargetARM32() = delete;
   TargetARM32(const TargetARM32 &) = delete;
   TargetARM32 &operator=(const TargetARM32 &) = delete;
 
 public:
   static void staticInit();
   // TODO(jvoung): return a unique_ptr.
   static TargetARM32 *create(Cfg *Func) { return new TargetARM32(Func); }
 
   void initNodeForLowering(CfgNode *Node) override {
     BoolComputations.forgetProducers();
     BoolComputations.recordProducers(Node);
     BoolComputations.dump(Func);
   }
 
   void translateOm1() override;
   void translateO2() override;
   bool doBranchOpt(Inst *I, const CfgNode *NextNode) override;
 
   SizeT getNumRegisters() const override { return RegARM32::Reg_NUM; }
   Variable *getPhysicalRegister(SizeT RegNum, Type Ty = IceType_void) override;
   IceString getRegName(SizeT RegNum, Type Ty) const override;
   llvm::SmallBitVector getRegisterSet(RegSetMask Include,
                                       RegSetMask Exclude) const override;
-  const llvm::SmallBitVector &getRegisterSetForType(Type Ty) const override {
-    return TypeToRegisterSet[Ty];
+  const llvm::SmallBitVector &
+  getRegistersForClass(const Variable *Var) const override {

[John, 2015/11/09 16:23:29]

This method should be renamed to, e.g., getRegistersForVariable.

[Jim Stichnoth, 2015/11/09 18:45:35]

Done.

+    RegClass RC = Var->getRegClass();
+    assert(RC < RC_Target);
+    return TypeToRegisterSet[RC];
   }
   const llvm::SmallBitVector &getAliasesForRegister(SizeT Reg) const override {
     return RegisterAliases[Reg];
   }
   bool hasFramePointer() const override { return UsesFramePointer; }
   void setHasFramePointer() override { UsesFramePointer = true; }
   SizeT getStackReg() const override { return RegARM32::Reg_sp; }
   SizeT getFrameOrStackReg() const override {
     return UsesFramePointer ? RegARM32::Reg_fp : RegARM32::Reg_sp;
   }
@@ skipping 458 matching lines @@
   /// centered on the given Var's offset plus StackAdjust, and use it.
   StackVariable *legalizeVariableSlot(Variable *Var, int32_t StackAdjust,
                                       Variable *OrigBaseReg);
 
   TargetARM32Features CPUFeatures;
   bool UsesFramePointer = false;
   bool NeedsStackAlignment = false;
   bool MaybeLeafFunc = true;
   size_t SpillAreaSizeBytes = 0;
   // TODO(jpp): std::array instead of array.
-  static llvm::SmallBitVector TypeToRegisterSet[IceType_NUM];
+  static llvm::SmallBitVector TypeToRegisterSet[RCARM32_NUM];
   static llvm::SmallBitVector RegisterAliases[RegARM32::Reg_NUM];
   static llvm::SmallBitVector ScratchRegs;
   llvm::SmallBitVector RegsUsed;
   VarList PhysicalRegisters[IceType_NUM];
 
   /// Helper class that understands the Calling Convention and register
   /// assignments. The first few integer type parameters can use r0-r3,
   /// regardless of their position relative to the floating-point/vector
   /// arguments in the argument list. Floating-point and vector arguments
   /// can use q0-q3 (aka d0-d7, s0-s15). For more information on the topic,
@@ skipping 141 matching lines @@
 
 private:
   ~TargetHeaderARM32() = default;
 
   TargetARM32Features CPUFeatures;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGARM32_H