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

runtime/lib/regexp.cc

Index: runtime/lib/regexp.cc
diff --git a/runtime/lib/regexp.cc b/runtime/lib/regexp.cc
index 7a50561109244c8f55282b3aedc2d02edff0e1f0..ad82af8778963702064beb92c4c3f61d97827560 100644
--- a/runtime/lib/regexp.cc
+++ b/runtime/lib/regexp.cc
@@ -87,10 +87,29 @@ DEFINE_NATIVE_ENTRY(RegExp_ExecuteMatch, 3) {
 
   if (FLAG_interpret_irregexp || FLAG_precompiled_runtime) {
     return BytecodeRegExpMacroAssembler::Interpret(regexp, subject, start_index,
-                                                   zone);
+                                                   /*sticky=*/false, zone);
   }
 
-  return IRRegExpMacroAssembler::Execute(regexp, subject, start_index, zone);
+  return IRRegExpMacroAssembler::Execute(regexp, subject, start_index,
+                                         /*sticky=*/false, zone);
 }
 
+
+DEFINE_NATIVE_ENTRY(RegExp_ExecuteMatchSticky, 3) {
+  // This function is intrinsified. See Intrinsifier::RegExp_ExecuteMatch.

[rmacnak, 2016/11/17 00:49:52]

MatchSticky

[Vyacheslav Egorov (Google), 2016/11/17 16:51:33]

Done.

+  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,
+                                                   /*sticky=*/true, zone);
+  }
+
+  return IRRegExpMacroAssembler::Execute(regexp, subject, start_index,
+                                         /*sticky=*/true, zone);
+}
+
+
 }  // namespace dart