Refactor construction of polymorphic loads, stores, and calls.

Rather than passing in a pair of unequal-length lists, pass the default
subgraph separately.  Construct the typecase from the top down rather than
the bottom up, so it doesn't need an intermediate zone list.

Also, change a basic block's 'last' instruction field to really be its last
instruction by correctly updating it when inserting and removing
instructions.

Review URL: http://codereview.chromium.org/6516016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -465,9 +465,16 @@ void HInstruction::PrintTo(StringStream* stream) const {
 void HInstruction::Unlink() {
   ASSERT(IsLinked());
   ASSERT(!IsControlInstruction());  // Must never move control instructions.
+  ASSERT(!IsBlockEntry());  // Doesn't make sense to delete these.
+  ASSERT(previous_ != NULL);
+  previous_->next_ = next_;
+  if (next_ == NULL) {
+    ASSERT(block()->last() == this);
+    block()->set_last(previous_);
+  } else {
+    next_->previous_ = previous_;
+  }
   clear_block();
-  if (previous_ != NULL) previous_->next_ = next_;
-  if (next_ != NULL) next_->previous_ = previous_;
 }
 
 

src/hydrogen.h

@@ -60,6 +60,8 @@ class HBasicBlock: public ZoneObject {
   HGraph* graph() const { return graph_; }
   const ZoneList<HPhi*>* phis() const { return &phis_; }
   HInstruction* first() const { return first_; }
+  HInstruction* last() const { return last_; }
+  void set_last(HInstruction* instr) { last_ = instr; }
   HInstruction* GetLastInstruction();
   HControlInstruction* end() const { return end_; }
   HLoopInformation* loop_information() const { return loop_information_; }
@@ -148,7 +150,7 @@ class HBasicBlock: public ZoneObject {
   HGraph* graph_;
   ZoneList<HPhi*> phis_;
   HInstruction* first_;
-  HInstruction* last_;  // Last non-control instruction of the block.
+  HInstruction* last_;
   HControlInstruction* end_;
   HLoopInformation* loop_information_;
   ZoneList<HBasicBlock*> predecessors_;
@@ -826,9 +828,10 @@ class HGraphBuilder: public AstVisitor {
                                 bool smi_and_map_check);
 
 
-  HBasicBlock* BuildTypeSwitch(ZoneMapList* maps,
-                               ZoneList<HSubgraph*>* subgraphs,
-                               HValue* receiver,
+  HBasicBlock* BuildTypeSwitch(HValue* receiver,
+                               ZoneMapList* maps,
+                               ZoneList<HSubgraph*>* body_graphs,
+                               HSubgraph* default_graph,
                                int join_id);
 
   TypeFeedbackOracle* oracle_;