[turbofan] Generate loop exits in the bytecode graph builder.

src/compiler/bytecode-graph-builder.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_
 #define V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_
 
 #include "src/compiler.h"
 #include "src/compiler/bytecode-branch-analysis.h"
+#include "src/compiler/bytecode-loop-analysis.h"
 #include "src/compiler/js-graph.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-flags.h"
 #include "src/interpreter/bytecodes.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // The BytecodeGraphBuilder produces a high-level IR graph based on
@@ skipping 120 matching lines @@
   void BuildJumpIfNotHole();
 
   // Simulates control flow by forward-propagating environments.
   void MergeIntoSuccessorEnvironment(int target_offset);
   void BuildLoopHeaderEnvironment(int current_offset);
   void SwitchToMergeEnvironment(int current_offset);
 
   // Simulates control flow that exits the function body.
   void MergeControlToLeaveFunction(Node* exit);
 
+  // Builds loop exit nodes for every exited loop between {origin_offset} and
+  // {target_offset}.

[Michael Starzinger, 2016/07/29 08:54:46]

nit: s/{origin_offset}/the current bytecode offset/

[Jarin, 2016/07/29 11:36:46]

Done.

+  void BuildLoopExitsForBranch(int target_offset);
+  void BuildLoopExitsForFunctionExit();
+  void BuildLoopExitsUntilLoop(int loop_offset);
+
   // Simulates entry and exit of exception handlers.
   void EnterAndExitExceptionHandlers(int current_offset);
 
   // Growth increment for the temporary buffer used to construct input lists to
   // new nodes.
   static const int kInputBufferSizeIncrement = 64;
 
   // The catch prediction from the handler table is reused.
   typedef HandlerTable::CatchPrediction CatchPrediction;
 
@@ skipping 39 matching lines @@
   }
 
   const BytecodeBranchAnalysis* branch_analysis() const {
     return branch_analysis_;
   }
 
   void set_branch_analysis(const BytecodeBranchAnalysis* branch_analysis) {
     branch_analysis_ = branch_analysis;
   }
 
+  const BytecodeLoopAnalysis* loop_analysis() const { return loop_analysis_; }
+
+  void set_loop_analysis(const BytecodeLoopAnalysis* loop_analysis) {
+    loop_analysis_ = loop_analysis;
+  }
+
 #define DECLARE_VISIT_BYTECODE(name, ...) void Visit##name();
   BYTECODE_LIST(DECLARE_VISIT_BYTECODE)
 #undef DECLARE_VISIT_BYTECODE
 
   Zone* local_zone_;
   JSGraph* jsgraph_;
   Handle<BytecodeArray> bytecode_array_;
   Handle<HandlerTable> exception_handler_table_;
   Handle<TypeFeedbackVector> feedback_vector_;
   const FrameStateFunctionInfo* frame_state_function_info_;
   const interpreter::BytecodeArrayIterator* bytecode_iterator_;
   const BytecodeBranchAnalysis* branch_analysis_;
+  const BytecodeLoopAnalysis* loop_analysis_;
   Environment* environment_;
   BailoutId osr_ast_id_;
 
   // Merge environments are snapshots of the environment at points where the
   // control flow merges. This models a forward data flow propagation of all
   // values from all predecessors of the merge in question.
   ZoneMap<int, Environment*> merge_environments_;
 
   // Exception handlers currently entered by the iteration.
   ZoneStack<ExceptionHandler> exception_handlers_;
@@ skipping 12 matching lines @@
   ZoneVector<Node*> exit_controls_;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeGraphBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_