Initial Subzero WASM prototype.

src/IceCfgNode.h

 //===- subzero/src/IceCfgNode.h - Control flow graph node -------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 54 matching lines @@
   /// \name Access predecessor and successor edge lists.
   /// @{
   const NodeList &getInEdges() const { return InEdges; }
   const NodeList &getOutEdges() const { return OutEdges; }
   /// @}
 
   /// \name Manage the instruction list.
   /// @{
   InstList &getInsts() { return Insts; }
   PhiList &getPhis() { return Phis; }
-  void appendInst(Inst *Instr);
+  void appendInst(Inst *Instr, bool AllowPhisAnywhere = false);
   void renumberInstructions();
   /// Rough and generally conservative estimate of the number of instructions in
   /// the block. It is updated when an instruction is added, but not when
   /// deleted. It is recomputed during renumberInstructions().
   InstNumberT getInstCountEstimate() const { return InstCountEstimate; }
   /// @}
 
   /// \name Manage predecessors and successors.
   /// @{
 
@@ skipping 17 matching lines @@
   void livenessAddIntervals(Liveness *Liveness, InstNumberT FirstInstNum,
                             InstNumberT LastInstNum);
   void contractIfEmpty();
   void doBranchOpt(const CfgNode *NextNode);
   void emit(Cfg *Func) const;
   void emitIAS(Cfg *Func) const;
   void dump(Cfg *Func) const;
 
   void profileExecutionCount(VariableDeclaration *Var);
 
+  void addOutEdge(CfgNode *Out) { OutEdges.push_back(Out); }
+  void addInEdge(CfgNode *In) { InEdges.push_back(In); }
+
+  bool hasSingleOutEdge() const {
+    return (getOutEdges().size() == 1 || getOutEdges()[0] == getOutEdges()[1]);
+  }
+
 private:
   CfgNode(Cfg *Func, SizeT Number);
   bool livenessValidateIntervals(Liveness *Liveness) const;
   Cfg *const Func;
   SizeT Number; /// invariant: Func->Nodes[Number]==this
   NodeString Name;
   SizeT LoopNestDepth = 0; /// the loop nest depth of this node
   bool HasReturn = false;  /// does this block need an epilog?
   bool NeedsPlacement = false;
   bool NeedsAlignment = false;       /// is sandboxing required?
   InstNumberT InstCountEstimate = 0; /// rough instruction count estimate
   NodeList InEdges;                  /// in no particular order
   NodeList OutEdges;                 /// in no particular order
   PhiList Phis;                      /// unordered set of phi instructions
   InstList Insts;                    /// ordered list of non-phi instructions
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICECFGNODE_H