Indirectly dispatch all backtracking jumps through the same block.

runtime/vm/compiler.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/block_scheduler.h"
@@ skipping 92 matching lines @@
     return builder.BuildGraph();
   }
 
   virtual void FinalizeCompilation() { }
 };
 
 
 class IrregexpCompilationPipeline : public DefaultCompilationPipeline {
  public:
   explicit IrregexpCompilationPipeline(Isolate* isolate)
-    : macro_assembler_(NULL),
+    : backtrack_goto_(NULL),
       isolate_(isolate) { }
 
   virtual void ParseFunction(ParsedFunction* parsed_function) {
     RegExpParser::ParseFunction(parsed_function);
     // Variables are allocated after compilation.
   }
 
   virtual FlowGraph* BuildFlowGraph(
       ParsedFunction* parsed_function,
       const ZoneGrowableArray<const ICData*>& ic_data_array,
       intptr_t osr_id) {
     // Compile to the dart IR.
     RegExpEngine::CompilationResult result =
         RegExpEngine::Compile(parsed_function->regexp_compile_data(),
                               parsed_function,
                               ic_data_array);
-    macro_assembler_ = result.macro_assembler;
+    backtrack_goto_ = result.backtrack_goto;
 
     // Allocate variables now that we know the number of locals.
     parsed_function->AllocateIrregexpVariables(result.num_stack_locals);
 
     // Build the flow graph.
     FlowGraphBuilder builder(parsed_function,
                              ic_data_array,
                              NULL,  // NULL = not inlining.
                              osr_id);
 
     return new(isolate_) FlowGraph(builder,
                                    result.graph_entry,
                                    result.num_blocks);
   }
 
   virtual void FinalizeCompilation() {
-    macro_assembler_->FinalizeBlockOffsetTable();
+    backtrack_goto_->ComputeOffsetTable(isolate_);
   }
 
  private:
-  IRRegExpMacroAssembler* macro_assembler_;
+  IndirectGotoInstr* backtrack_goto_;
   Isolate* isolate_;
 };
 
 CompilationPipeline* CompilationPipeline::New(Isolate* isolate,
                                               const Function& function) {
   if (function.IsIrregexpFunction()) {
     return new(isolate) IrregexpCompilationPipeline(isolate);
   } else {
     return new(isolate) DefaultCompilationPipeline();
   }
@@ skipping 1013 matching lines @@
     const Object& result =
       PassiveObject::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart