Std:unordered_map removed from Optimizer for improved performance

third_party/subzero/src/IceCfgNode.h

@@ -127,6 +127,9 @@ public:
   }
   CfgNode *shortCircuit();
 
+  inline void* getExternalData() const { return externalData; }
+  inline void setExternalData(void* data) { externalData = data; }
+
 private:
   CfgNode(Cfg *Func, SizeT Number)
       : Func(Func), Number(Number), NumberOrig(Number),
@@ -145,6 +148,11 @@ private:
   NodeList OutEdges;                 /// in no particular order
   PhiList Phis;                      /// unordered set of phi instructions
   InstList Insts;                    /// ordered list of non-phi instructions
+
+  /// External data can be set by an optimizer to compute and retain any
+  /// information related to the current node. All the memory used to
+  /// store this information must be managed by the optimizer.
+  void* externalData = nullptr;
 };
 
 } // end of namespace Ice

third_party/subzero/src/IceInst.h

@@ -199,6 +199,9 @@ public:
     llvm::report_fatal_error("Inst unexpectedly deleted");
   }
 
+  inline void* getExternalData() const { return externalData; }
+  inline void setExternalData(void* data) { externalData = data; }
+
 protected:
   Inst(Cfg *Func, InstKind Kind, SizeT MaxSrcs, Variable *Dest);
   void addSource(Operand *Src) {
@@ -236,6 +239,10 @@ protected:
   /// live range recorded in a basic block has at most one start and at most one
   /// end.
   bool IsDestRedefined = false;
+  /// External data can be set by an optimizer to compute and retain any
+  /// information related to the current instruction. All the memory used to
+  /// store this information must be managed by the optimizer.
+  void* externalData = nullptr;
 
   Variable *Dest;
   const SizeT MaxSrcs; // only used for assert

third_party/subzero/src/IceOperand.h

@@ -106,6 +106,9 @@ public:
     return 0;
   }
 
+  inline void* getExternalData() const { return externalData; }
+  inline void setExternalData(void* data) { externalData = data; }
+
 protected:
   Operand(OperandKind Kind, Type Ty) : Ty(Ty), Kind(Kind) {
     // It is undefined behavior to have a larger value in the enum
@@ -117,6 +120,11 @@ protected:
   /// Vars and NumVars are initialized by the derived class.
   SizeT NumVars = 0;
   Variable **Vars = nullptr;
+
+  /// External data can be set by an optimizer to compute and retain any
+  /// information related to the current operand. All the memory used to
+  /// store this information must be managed by the optimizer.
+  void* externalData = nullptr;
 };
 
 template <class StreamType>
@@ -854,6 +862,9 @@ public:
 
   SizeT hashValue() const override { return std::hash<SizeT>()(getIndex()); }
 
+  inline void* getExternalData() const { return externalData; }
+  inline void setExternalData(void* data) { externalData = data; }
+
 protected:
   Variable(const Cfg *Func, OperandKind K, Type Ty, SizeT Index)
       : Operand(K, Ty), Number(Index),
@@ -895,6 +906,10 @@ protected:
   /// This Variable may be "linked" to another Variable, such that if neither
   /// Variable gets a register, they are guaranteed to share a stack location.
   Variable *LinkedTo = nullptr;
+  /// External data can be set by an optimizer to compute and retain any
+  /// information related to the current variable. All the memory used to
+  /// store this information must be managed by the optimizer.
+  void* externalData = nullptr;
 };
 
 // Variable64On32 represents a 64-bit variable on a 32-bit architecture. In