275   // are required, from _cnt to _max-1 are precedence edges.
 276   node_idx_t _cnt;              // Total number of required Node inputs.
 277 
 278   node_idx_t _max;              // Actual length of input array.
 279 
 280   // Output edges are an unordered list of def-use edges which exactly
 281   // correspond to required input edges which point from other nodes
 282   // to this one.  Thus the count of the output edges is the number of
 283   // users of this node.
 284   node_idx_t _outcnt;           // Total number of Node outputs.
 285 
 286   node_idx_t _outmax;           // Actual length of output array.
 287 
 288   // Grow the actual input array to the next larger power-of-2 bigger than len.
 289   void grow( uint len );
 290   // Grow the output array to the next larger power-of-2 bigger than len.
 291   void out_grow( uint len );
 292 
 293  public:
 294   // Each Node is assigned a unique small/dense number.  This number is used
 295   // to index into auxiliary arrays of data and bitvectors.
 296   // It is declared const to defend against inadvertant assignment,
 297   // since it is used by clients as a naked field.





 298   const node_idx_t _idx;

 299 
 300   // Get the (read-only) number of input edges
 301   uint req() const { return _cnt; }
 302   uint len() const { return _max; }
 303   // Get the (read-only) number of output edges
 304   uint outcnt() const { return _outcnt; }
 305 
 306 #if OPTO_DU_ITERATOR_ASSERT
 307   // Iterate over the out-edges of this node.  Deletions are illegal.
 308   inline DUIterator outs() const;
 309   // Use this when the out array might have changed to suppress asserts.
 310   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 311   // Does the node have an out at this position?  (Used for iteration.)
 312   inline bool has_out(DUIterator& i) const;
 313   inline Node*    out(DUIterator& i) const;
 314   // Iterate over the out-edges of this node.  All changes are illegal.
 315   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 316   inline Node*    fast_out(DUIterator_Fast& i) const;
 317   // Iterate over the out-edges of this node, deleting one at a time.
 318   inline DUIterator_Last last_outs(DUIterator_Last& min) const;

 275   // are required, from _cnt to _max-1 are precedence edges.
 276   node_idx_t _cnt;              // Total number of required Node inputs.
 277 
 278   node_idx_t _max;              // Actual length of input array.
 279 
 280   // Output edges are an unordered list of def-use edges which exactly
 281   // correspond to required input edges which point from other nodes
 282   // to this one.  Thus the count of the output edges is the number of
 283   // users of this node.
 284   node_idx_t _outcnt;           // Total number of Node outputs.
 285 
 286   node_idx_t _outmax;           // Actual length of output array.
 287 
 288   // Grow the actual input array to the next larger power-of-2 bigger than len.
 289   void grow( uint len );
 290   // Grow the output array to the next larger power-of-2 bigger than len.
 291   void out_grow( uint len );
 292 
 293  public:
 294   // Each Node is assigned a unique small/dense number.  This number is used
 295   // to index into auxiliary arrays of data and bit vectors.
 296   // The field _idx is declared constant to defend against inadvertent assignments,
 297   // since it is used by clients as a naked field. However, the field's value can be
 298   // changed using the set_idx() method.
 299   //
 300   // The PhaseRenumberLive phase renumbers nodes based on liveness information.
 301   // Therefore, it updates the value of the _idx field. The parse-time _idx is
 302   // preserved in _parse_idx.
 303   const node_idx_t _idx;
 304   DEBUG_ONLY(const node_idx_t _parse_idx;)
 305 
 306   // Get the (read-only) number of input edges
 307   uint req() const { return _cnt; }
 308   uint len() const { return _max; }
 309   // Get the (read-only) number of output edges
 310   uint outcnt() const { return _outcnt; }
 311 
 312 #if OPTO_DU_ITERATOR_ASSERT
 313   // Iterate over the out-edges of this node.  Deletions are illegal.
 314   inline DUIterator outs() const;
 315   // Use this when the out array might have changed to suppress asserts.
 316   inline DUIterator& refresh_out_pos(DUIterator& i) const;
 317   // Does the node have an out at this position?  (Used for iteration.)
 318   inline bool has_out(DUIterator& i) const;
 319   inline Node*    out(DUIterator& i) const;
 320   // Iterate over the out-edges of this node.  All changes are illegal.
 321   inline DUIterator_Fast fast_outs(DUIterator_Fast& max) const;
 322   inline Node*    fast_out(DUIterator_Fast& i) const;
 323   // Iterate over the out-edges of this node, deleting one at a time.
 324   inline DUIterator_Last last_outs(DUIterator_Last& min) const;