Implement loop invariant code motion for check instructions.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 11934)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -428,6 +428,7 @@
 
  private:
   friend class Definition;  // Needed for InsertBefore, InsertAfter.
+  friend class LICM;

[srdjan, 2012/09/06 13:44:26]

Please add why, or move the comment if it is valid for both.

[Florian Schneider, 2012/09/06 13:49:30]

 Moved it to below where the comment applies.

 
   // Classes that set deopt_id_.
   friend class UnboxDoubleInstr;
@@ -604,6 +605,8 @@
     dominated_blocks_.Add(block);
   }
 
+  bool Dominates(BlockEntryInstr* other) const;
+
   Instruction* last_instruction() const { return last_instruction_; }
   void set_last_instruction(Instruction* instr) { last_instruction_ = instr; }
 
@@ -644,6 +647,13 @@
 
   intptr_t try_index() const { return try_index_; }
 
+  const ZoneGrowableArray<BlockEntryInstr*>* loop_info() const {
+    return loop_info_;
+  }
+  void set_loop_info(const ZoneGrowableArray<BlockEntryInstr*>* loop_info) {
+    loop_info_ = loop_info;
+  }
+
  protected:
   explicit BlockEntryInstr(intptr_t try_index)
       : try_index_(try_index),
@@ -653,7 +663,8 @@
         dominator_(NULL),
         dominated_blocks_(1),
         last_instruction_(NULL),
-        parallel_move_(NULL) { }
+        parallel_move_(NULL),
+        loop_info_(NULL) { }
 
  private:
   const intptr_t try_index_;
@@ -673,6 +684,8 @@
   // connect live ranges at the start of the block.
   ParallelMoveInstr* parallel_move_;
 
+  const ZoneGrowableArray<BlockEntryInstr*>* loop_info_;
+
   DISALLOW_COPY_AND_ASSIGN(BlockEntryInstr);
 };
 
@@ -1003,6 +1016,9 @@
   virtual void RecordAssignedVars(BitVector* assigned_vars,
                                   intptr_t fixed_parameter_count);
 
+  // Get the block entry for that instruction.
+  virtual BlockEntryInstr* GetBlock() const;
+
   // Printing support. These functions are sometimes overridden for custom
   // formatting. Otherwise, it prints in the format "opcode(op1, op2, op3)".
   virtual void PrintTo(BufferFormatter* f) const;
@@ -1036,6 +1052,8 @@
     }
   }
 
+  // Get the block entry for that instruction.
+  virtual BlockEntryInstr* GetBlock() const { return block(); }
   JoinEntryInstr* block() const { return block_; }
 
   virtual RawAbstractType* CompileType() const;
@@ -1097,12 +1115,16 @@
 
 class ParameterInstr : public Definition {
  public:
-  explicit ParameterInstr(intptr_t index) : index_(index) { }
+  explicit ParameterInstr(intptr_t index, GraphEntryInstr* block)
+      : index_(index), block_(block) { }
 
   DECLARE_INSTRUCTION(Parameter)
 
   intptr_t index() const { return index_; }
 
+  // Get the block entry for that instruction.
+  virtual BlockEntryInstr* GetBlock() const { return block_; }
+
   // Compile type of the passed-in parameter.
   virtual RawAbstractType* CompileType() const;
 
@@ -1135,6 +1157,7 @@
 
  private:
   const intptr_t index_;
+  GraphEntryInstr* block_;
 
   DISALLOW_COPY_AND_ASSIGN(ParameterInstr);
 };