VM: Optimize RegExp.matchAsPrefix(...) by generating a sticky RegExp specialization.

runtime/lib/regexp.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 "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/regexp_parser.h"
@@ skipping 60 matching lines @@
   const String& errmsg = String::Handle(
       String::New("Regular expression is not initialized yet. "));
   const String& message = String::Handle(String::Concat(errmsg, pattern));
   const Array& args = Array::Handle(Array::New(1));
   args.SetAt(0, message);
   Exceptions::ThrowByType(Exceptions::kFormat, args);
   return Object::null();
 }
 
 
+static RawObject* ExecuteMatch(Zone* zone,
+                               NativeArguments* arguments,
+                               bool sticky) {
+  const RegExp& regexp = RegExp::CheckedHandle(arguments->NativeArgAt(0));
+  ASSERT(!regexp.IsNull());
+  GET_NON_NULL_NATIVE_ARGUMENT(String, subject, arguments->NativeArgAt(1));
+  GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_index, arguments->NativeArgAt(2));
+
+  if (FLAG_interpret_irregexp) {
+    return BytecodeRegExpMacroAssembler::Interpret(regexp, subject, start_index,
+                                                   /*sticky=*/sticky, zone);
+  }
+
+  return IRRegExpMacroAssembler::Execute(regexp, subject, start_index,
+                                         /*sticky=*/sticky, zone);
+}
+
+
 DEFINE_NATIVE_ENTRY(RegExp_ExecuteMatch, 3) {
   // This function is intrinsified. See Intrinsifier::RegExp_ExecuteMatch.
-  const RegExp& regexp = RegExp::CheckedHandle(arguments->NativeArgAt(0));
-  ASSERT(!regexp.IsNull());
-  GET_NON_NULL_NATIVE_ARGUMENT(String, subject, arguments->NativeArgAt(1));
-  GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_index, arguments->NativeArgAt(2));
-
-  if (FLAG_interpret_irregexp || FLAG_precompiled_runtime) {
-    return BytecodeRegExpMacroAssembler::Interpret(regexp, subject, start_index,
-                                                   zone);
-  }
-
-  return IRRegExpMacroAssembler::Execute(regexp, subject, start_index, zone);
+  return ExecuteMatch(zone, arguments, /*sticky=*/false);
 }
 
+
+DEFINE_NATIVE_ENTRY(RegExp_ExecuteMatchSticky, 3) {
+  // This function is intrinsified. See Intrinsifier::RegExp_ExecuteMatchSticky.
+  return ExecuteMatch(zone, arguments, /*sticky=*/true);
+}
+
+
 }  // namespace dart