Get rid of the function sorting in for polymorphic calls.

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6754 matching lines @@
         target, static_cast<HValue*>(NULL),
         HObjectAccess::ForFunctionContextPointer());
     return NewArgumentAdaptorCall(target, context,
         argument_count, param_count_value);
   }
   UNREACHABLE();
   return NULL;
 }
 
 
-class FunctionSorter {
- public:
-  FunctionSorter() : index_(0), ticks_(0), ast_length_(0), src_length_(0) { }
-  FunctionSorter(int index, int ticks, int ast_length, int src_length)
-      : index_(index),
-        ticks_(ticks),
-        ast_length_(ast_length),
-        src_length_(src_length) { }
-
-  int index() const { return index_; }
-  int ticks() const { return ticks_; }
-  int ast_length() const { return ast_length_; }
-  int src_length() const { return src_length_; }
-
- private:
-  int index_;
-  int ticks_;
-  int ast_length_;
-  int src_length_;
-};
-
-
-inline bool operator<(const FunctionSorter& lhs, const FunctionSorter& rhs) {
-  int diff = lhs.ticks() - rhs.ticks();
-  if (diff != 0) return diff > 0;
-  diff = lhs.ast_length() - rhs.ast_length();
-  if (diff != 0) return diff < 0;
-  return lhs.src_length() < rhs.src_length();
-}
-
-
 void HOptimizedGraphBuilder::HandlePolymorphicCallNamed(
     Call* expr,
     HValue* receiver,
     SmallMapList* types,
     Handle<String> name) {
   int argument_count = expr->arguments()->length() + 1;  // Includes receiver.
-  FunctionSorter order[kMaxCallPolymorphism];
 
   bool handle_smi = false;
   bool handled_string = false;
-  int ordered_functions = 0;
 
-  for (int i = 0;
-       i < types->length() && ordered_functions < kMaxCallPolymorphism;
-       ++i) {
+  for (int i = 0; i < types->length(); ++i) {

[Toon Verwaest, 2014/02/11 10:32:48]

Please put back the MaxCallPolymorphism; which will force you to put back the
type()->Is(Type::String()) thing below to keep the limits of both loops in sync.

[Benedikt Meurer, 2014/02/11 10:34:55]

Done.

     PropertyAccessInfo info(this, LOAD, ToType(types->at(i)), name);
     if (info.CanAccessMonomorphic() &&
         info.lookup()->IsConstant() &&
         info.constant()->IsJSFunction()) {
-      if (info.type()->Is(Type::String())) {
-        if (handled_string) continue;
-        handled_string = true;
-      }
-      Handle<JSFunction> target = Handle<JSFunction>::cast(info.constant());
       if (info.type()->Is(Type::Number())) {
         handle_smi = true;
+        break;
       }
-      expr->set_target(target);
-      order[ordered_functions++] =
-          FunctionSorter(i,
-                         expr->target()->shared()->profiler_ticks(),
-                         InliningAstSize(expr->target()),
-                         expr->target()->shared()->SourceSize());
     }
   }
 
-  std::sort(order, order + ordered_functions);
-
   HBasicBlock* number_block = NULL;
   HBasicBlock* join = NULL;
   handled_string = false;
   int count = 0;
 
-  for (int fn = 0; fn < ordered_functions; ++fn) {
-    int i = order[fn].index();
+  for (int i = 0; i < types->length(); ++i) {
     PropertyAccessInfo info(this, LOAD, ToType(types->at(i)), name);
+    if (!info.CanAccessMonomorphic() ||
+        !info.lookup()->IsConstant() ||
+        !info.constant()->IsJSFunction()) {
+      continue;
+    }
     if (info.type()->Is(Type::String())) {
       if (handled_string) continue;
       handled_string = true;
     }
     // Reloads the target.
     info.CanAccessMonomorphic();
     Handle<JSFunction> target = Handle<JSFunction>::cast(info.constant());
 
     expr->set_target(target);
     if (count == 0) {
@@ skipping 70 matching lines @@
       if (!ast_context()->IsEffect()) Push(call);
     }
 
     if (current_block() != NULL) Goto(join);
     set_current_block(if_false);
   }
 
   // Finish up.  Unconditionally deoptimize if we've handled all the maps we
   // know about and do not want to handle ones we've never seen.  Otherwise
   // use a generic IC.
-  if (ordered_functions == types->length() && FLAG_deoptimize_uncommon_cases) {
+  if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
     // Because the deopt may be the only path in the polymorphic call, make sure
     // that the environment stack matches the depth on deopt that it otherwise
     // would have had after a successful call.
     Drop(1);  // Drop receiver.
     if (!ast_context()->IsEffect()) Push(graph()->GetConstant0());
     FinishExitWithHardDeoptimization("Unknown map in polymorphic call", join);
   } else {
     Property* prop = expr->expression()->AsProperty();
     HInstruction* function = BuildNamedGeneric(
         LOAD, receiver, name, NULL, prop->IsUninitialized());
@@ skipping 4242 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal