VM(RegExp): Allow OSR optimization of RegExp :matcher functions.

runtime/vm/regexp_assembler_ir.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_REGEXP_ASSEMBLER_IR_H_
 #define RUNTIME_VM_REGEXP_ASSEMBLER_IR_H_
 
 #include "vm/assembler.h"
 #include "vm/intermediate_language.h"
 #include "vm/object.h"
@@ skipping 14 matching lines @@
   //        throw the exception.
   // FAILURE: Matching failed.
   // SUCCESS: Matching succeeded, and the output array has been filled with
   //        capture positions.
   enum Result { RETRY = -2, EXCEPTION = -1, FAILURE = 0, SUCCESS = 1 };
 
   IRRegExpMacroAssembler(intptr_t specialization_cid,
                          intptr_t capture_count,
                          const ParsedFunction* parsed_function,
                          const ZoneGrowableArray<const ICData*>& ic_data_array,
+                         intptr_t osr_id,
                          Zone* zone);
   virtual ~IRRegExpMacroAssembler();
 
   virtual bool CanReadUnaligned();
 
   static RawArray* Execute(const RegExp& regexp,
                            const String& input,
                            const Smi& start_offset,
                            bool sticky,
                            Zone* zone);
@@ skipping 232 matching lines @@
   // current position, into the current-character register.
   void LoadCurrentCharacterUnchecked(intptr_t cp_offset,
                                      intptr_t character_count);
 
   // Returns the character within the passed string at the specified index.
   Value* CharacterAt(LocalVariable* index);
 
   // Load a number of characters starting from index in the pattern string.
   Value* LoadCodeUnitsAt(LocalVariable* index, intptr_t character_count);
 
-  // Check whether preemption has been requested.
-  void CheckPreemption();
+  // Check whether preemption has been requested. Also serves as an OSR entry.
+  void CheckPreemption(bool is_backtrack);
 
   // Byte size of chars in the string to match (decided by the Mode argument)
   inline intptr_t char_size() { return static_cast<int>(mode_); }
 
   // Equivalent to a conditional branch to the label, unless the label
   // is NULL, in which case it is a conditional Backtrack.
   void BranchOrBacktrack(ComparisonInstr* comparison,
                          BlockLabel* true_successor);
 
   // Set up all local variables and parameters.
@@ skipping 37 matching lines @@
   Definition* PeekStack();
   void CheckStackLimit();
   void GrowStack();
 
   // Prints the specified argument. Used for debugging.
   void Print(PushArgumentInstr* argument);
 
   // A utility class tracking ids of various objects such as blocks, temps, etc.
   class IdAllocator : public ValueObject {
    public:
-    IdAllocator() : next_id(0) {}
+    explicit IdAllocator(intptr_t first_id = 0) : next_id(first_id) {}
 
     intptr_t Count() const { return next_id; }
     intptr_t Alloc(intptr_t count = 1) {
       ASSERT(count >= 0);
       intptr_t current_id = next_id;
       next_id += count;
       return current_id;
     }
     void Dealloc(intptr_t count = 1) {
       ASSERT(count <= next_id);
@@ skipping 78 matching lines @@
   IdAllocator temp_id_;
   IdAllocator arg_id_;
   IdAllocator local_id_;
   IdAllocator indirect_id_;
 };
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_REGEXP_ASSEMBLER_IR_H_