Subzero: Refactor x86 register representation to actively use aliases.

src/IceTargetLoweringARM32.h

Index: src/IceTargetLoweringARM32.h
diff --git a/src/IceTargetLoweringARM32.h b/src/IceTargetLoweringARM32.h
index 62a903ded6cc37e43ae0695e5d1ea77c78b9a223..631060f1d9ce2a7756979cb8c3e7f65d3e9df770 100644
--- a/src/IceTargetLoweringARM32.h
+++ b/src/IceTargetLoweringARM32.h
@@ -48,6 +48,9 @@ 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;
@@ -74,8 +77,11 @@ public:
   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];
@@ -554,7 +560,7 @@ protected:
   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;