Optimize Function.prototype.call

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/hydrogen.h"
 
 #include <algorithm>
 
 #include "src/v8.h"
 
@@ skipping 7909 matching lines @@
   if (TryInlineApiSetter(setter, receiver_map, id)) return true;
   return TryInline(setter,
                    1,
                    implicit_return_value,
                    id, assignment_id,
                    SETTER_CALL_RETURN,
                    source_position());
 }
 
 
-bool HOptimizedGraphBuilder::TryInlineApply(Handle<JSFunction> function,
-                                            Call* expr,
-                                            int arguments_count) {
+bool HOptimizedGraphBuilder::TryInlineIndirectCall(Handle<JSFunction> function,
+                                                   Call* expr,
+                                                   int arguments_count) {
   return TryInline(function,
                    arguments_count,
                    NULL,
                    expr->id(),
                    expr->ReturnId(),
                    NORMAL_RETURN,
                    ScriptPositionToSourcePosition(expr->position()));
 }
 
 
@@ skipping 31 matching lines @@
     default:
       // Not supported for inlining yet.
       break;
   }
   return false;
 }
 
 
 bool HOptimizedGraphBuilder::TryInlineBuiltinMethodCall(
     Call* expr,
-    HValue* receiver,
-    Handle<Map> receiver_map) {
+    Handle<JSFunction> function,
+    Handle<Map> receiver_map,
+    int args_count_no_receiver,
+    int drop_extra) {
+  if (!function->shared()->HasBuiltinFunctionId()) return false;
+  BuiltinFunctionId id = function->shared()->builtin_function_id();
+  int argument_count = args_count_no_receiver + 1;  // Plus receiver.
+
+  if (receiver_map.is_null()) {
+    HValue* receiver = environment()->ExpressionStackAt(args_count_no_receiver);
+    if (receiver->IsConstant() &&
+        HConstant::cast(receiver)->handle(isolate())->IsHeapObject()) {
+      receiver_map = handle(Handle<HeapObject>::cast(
+          HConstant::cast(receiver)->handle(isolate()))->map());
+    }
+  }
   // Try to inline calls like Math.* as operations in the calling function.
-  if (!expr->target()->shared()->HasBuiltinFunctionId()) return false;
-  BuiltinFunctionId id = expr->target()->shared()->builtin_function_id();
-  int argument_count = expr->arguments()->length() + 1;  // Plus receiver.
   switch (id) {
     case kStringCharCodeAt:
     case kStringCharAt:
       if (argument_count == 2) {
         HValue* index = Pop();
         HValue* string = Pop();
-        Drop(1);  // Function.
+        Drop(1 + drop_extra);  // Function + extra.
         HInstruction* char_code =
             BuildStringCharCodeAt(string, index);
         if (id == kStringCharCodeAt) {
           ast_context()->ReturnInstruction(char_code, expr->id());
           return true;
         }
         AddInstruction(char_code);
         HInstruction* result = NewUncasted<HStringCharFromCode>(char_code);
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kStringFromCharCode:
       if (argument_count == 2) {
         HValue* argument = Pop();
-        Drop(2);  // Receiver and function.
+        Drop(2 + drop_extra);  // Receiver and function + extra.
         HInstruction* result = NewUncasted<HStringCharFromCode>(argument);
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kMathExp:
       if (!FLAG_fast_math) break;
       // Fall through if FLAG_fast_math.
     case kMathRound:
     case kMathFloor:
     case kMathAbs:
     case kMathSqrt:
     case kMathLog:
     case kMathClz32:
       if (argument_count == 2) {
         HValue* argument = Pop();
-        Drop(2);  // Receiver and function.
+        Drop(2 + drop_extra);  // Receiver and function + extra.
         HInstruction* op = NewUncasted<HUnaryMathOperation>(argument, id);
         ast_context()->ReturnInstruction(op, expr->id());
         return true;
       }
       break;
     case kMathPow:
       if (argument_count == 3) {
         HValue* right = Pop();
         HValue* left = Pop();
-        Drop(2);  // Receiver and function.
+        Drop(2 + drop_extra);  // Receiver and function + extra.
         HInstruction* result = NULL;
         // Use sqrt() if exponent is 0.5 or -0.5.
         if (right->IsConstant() && HConstant::cast(right)->HasDoubleValue()) {
           double exponent = HConstant::cast(right)->DoubleValue();
           if (exponent == 0.5) {
             result = NewUncasted<HUnaryMathOperation>(left, kMathPowHalf);
           } else if (exponent == -0.5) {
             HValue* one = graph()->GetConstant1();
             HInstruction* sqrt = AddUncasted<HUnaryMathOperation>(
                 left, kMathPowHalf);
@@ skipping 11 matching lines @@
         }
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kMathMax:
     case kMathMin:
       if (argument_count == 3) {
         HValue* right = Pop();
         HValue* left = Pop();
-        Drop(2);  // Receiver and function.
+        Drop(2 + drop_extra);  // Receiver and function + extra.
         HMathMinMax::Operation op = (id == kMathMin) ? HMathMinMax::kMathMin
                                                      : HMathMinMax::kMathMax;
         HInstruction* result = NewUncasted<HMathMinMax>(left, right, op);
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kMathImul:
       if (argument_count == 3) {
         HValue* right = Pop();
         HValue* left = Pop();
-        Drop(2);  // Receiver and function.
+        Drop(2 + drop_extra);  // Receiver and function + extra.
         HInstruction* result = HMul::NewImul(zone(), context(), left, right);
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kArrayPop: {
       if (receiver_map.is_null()) return false;
       if (receiver_map->instance_type() != JS_ARRAY_TYPE) return false;
       ElementsKind elements_kind = receiver_map->elements_kind();
       if (!IsFastElementsKind(elements_kind)) return false;
       if (receiver_map->is_observed()) return false;
       ASSERT(receiver_map->is_extensible());
 
-      Drop(expr->arguments()->length());
+      Drop(args_count_no_receiver);
       HValue* result;
       HValue* reduced_length;
       HValue* receiver = Pop();
 
       HValue* checked_object = AddCheckMap(receiver, receiver_map);
       HValue* length = Add<HLoadNamedField>(
           checked_object, static_cast<HValue*>(NULL),
           HObjectAccess::ForArrayLength(elements_kind));
 
-      Drop(1);  // Function.
+      Drop(1 + drop_extra);  // Function + extra.
 
       { NoObservableSideEffectsScope scope(this);
         IfBuilder length_checker(this);
 
         HValue* bounds_check = length_checker.If<HCompareNumericAndBranch>(
             length, graph()->GetConstant0(), Token::EQ);
         length_checker.Then();
 
         if (!ast_context()->IsEffect()) Push(graph()->GetConstantUndefined());
 
@@ skipping 45 matching lines @@
       // inlined version can't be used.
       if (receiver_map->DictionaryElementsInPrototypeChainOnly()) return false;
       // If there currently can be no elements accessors on the prototype chain,
       // it doesn't mean that there won't be any later. Install a full prototype
       // chain check to trap element accessors being installed on the prototype
       // chain, which would cause elements to go to dictionary mode and result
       // in a map change.
       Handle<JSObject> prototype(JSObject::cast(receiver_map->prototype()));
       BuildCheckPrototypeMaps(prototype, Handle<JSObject>());
 
-      const int argc = expr->arguments()->length();
+      const int argc = args_count_no_receiver;
       if (argc != 1) return false;
 
       HValue* value_to_push = Pop();
       HValue* array = Pop();
-      Drop(1);  // Drop function.
+      Drop(1 + drop_extra);  // Drop function + extra.
 
       HInstruction* new_size = NULL;
       HValue* length = NULL;
 
       {
         NoObservableSideEffectsScope scope(this);
 
         length = Add<HLoadNamedField>(array, static_cast<HValue*>(NULL),
           HObjectAccess::ForArrayLength(elements_kind));
 
@@ skipping 31 matching lines @@
       // chain check to trap element accessors being installed on the prototype
       // chain, which would cause elements to go to dictionary mode and result
       // in a map change.
       BuildCheckPrototypeMaps(
           handle(JSObject::cast(receiver_map->prototype()), isolate()),
           Handle<JSObject>::null());
 
       // Threshold for fast inlined Array.shift().
       HConstant* inline_threshold = Add<HConstant>(static_cast<int32_t>(16));
 
-      Drop(expr->arguments()->length());
+      Drop(args_count_no_receiver);
       HValue* receiver = Pop();
       HValue* function = Pop();
+      Drop(drop_extra);  // Drop extras after function.
       HValue* result;
 
       {
         NoObservableSideEffectsScope scope(this);
 
         HValue* length = Add<HLoadNamedField>(
             receiver, static_cast<HValue*>(NULL),
             HObjectAccess::ForArrayLength(kind));
 
         IfBuilder if_lengthiszero(this);
@@ skipping 91 matching lines @@
       // it doesn't mean that there won't be any later. Install a full prototype
       // chain check to trap element accessors being installed on the prototype
       // chain, which would cause elements to go to dictionary mode and result
       // in a map change.
       BuildCheckPrototypeMaps(
           handle(JSObject::cast(receiver_map->prototype()), isolate()),
           Handle<JSObject>::null());
 
       HValue* search_element = Pop();
       HValue* receiver = Pop();
-      Drop(1);  // Drop function.
+      Drop(1 + drop_extra);  // Drop function + extra.
 
       ArrayIndexOfMode mode = (id == kArrayIndexOf)
           ? kFirstIndexOf : kLastIndexOf;
       HValue* index = BuildArrayIndexOf(receiver, search_element, kind, mode);
 
       if (!ast_context()->IsEffect()) Push(index);
       Add<HSimulate>(expr->id(), REMOVABLE_SIMULATE);
       if (!ast_context()->IsEffect()) Drop(1);
       ast_context()->ReturnValue(index);
       return true;
@@ skipping 176 matching lines @@
   HInstruction* call = New<HCallWithDescriptor>(
       code_value, argc + 1, descriptor,
       Vector<HValue*>(op_vals, descriptor->environment_length()));
 
   if (drop_extra) Drop(1);  // Drop function.
   ast_context()->ReturnInstruction(call, ast_id);
   return true;
 }
 
 
-bool HOptimizedGraphBuilder::TryCallApply(Call* expr) {
+void HOptimizedGraphBuilder::HandleIndirectCall(Call* expr,
+                                                HValue* function,
+                                                int arguments_count,
+                                                int drop_extra) {
+  Handle<JSFunction> known_function;
+  int args_count_no_receiver = arguments_count - 1;
+  if (function->IsConstant() &&
+      HConstant::cast(function)->handle(isolate())->IsJSFunction()) {
+    known_function = Handle<JSFunction>::cast(
+        HConstant::cast(function)->handle(isolate()));
+    if (TryInlineIndirectCall(known_function, expr, args_count_no_receiver)) {
+      Drop(drop_extra);
+      return;
+    }
+
+    Handle<Map> map;
+    if (TryInlineBuiltinMethodCall(expr, known_function, map,
+                                   args_count_no_receiver, drop_extra)) {
+      if (FLAG_trace_inlining) {
+        PrintF("Inlining builtin ");
+        known_function->ShortPrint();
+        PrintF("\n");
+      }
+      return;
+    }
+  }
+
+  PushArgumentsFromEnvironment(arguments_count);
+  HInvokeFunction* call = New<HInvokeFunction>(
+      function, known_function, arguments_count);
+  Drop(1 + drop_extra);  // Function + extra.
+  ast_context()->ReturnInstruction(call, expr->id());
+}
+
+
+bool HOptimizedGraphBuilder::TryIndirectCall(Call* expr) {
   ASSERT(expr->expression()->IsProperty());
 
   if (!expr->IsMonomorphic()) {
     return false;
   }
+
   Handle<Map> function_map = expr->GetReceiverTypes()->first();
   if (function_map->instance_type() != JS_FUNCTION_TYPE ||
-      !expr->target()->shared()->HasBuiltinFunctionId() ||
-      expr->target()->shared()->builtin_function_id() != kFunctionApply) {
+      !expr->target()->shared()->HasBuiltinFunctionId()) {
     return false;
   }
 
-  if (current_info()->scope()->arguments() == NULL) return false;
+  switch (expr->target()->shared()->builtin_function_id()) {
+    case kFunctionCall: {
+      BuildFunctionCall(expr);
+      return true;
+    }
+    case kFunctionApply: {
+      // For .apply, only the pattern f.apply(receiver, arguments)
+      // is supported.
+      if (current_info()->scope()->arguments() == NULL) return false;
 
+      ZoneList<Expression*>* args = expr->arguments();
+      if (args->length() != 2) return false;
+
+      VariableProxy* arg_two = args->at(1)->AsVariableProxy();
+      if (arg_two == NULL || !arg_two->var()->IsStackAllocated()) return false;
+      HValue* arg_two_value = LookupAndMakeLive(arg_two->var());
+      if (!arg_two_value->CheckFlag(HValue::kIsArguments)) return false;
+      BuildFunctionApply(expr);
+      return true;
+    }
+    default: {
+      return false;
+    }
+  }
+  UNREACHABLE();
+}
+
+
+void HOptimizedGraphBuilder::BuildFunctionApply(Call* expr) {
   ZoneList<Expression*>* args = expr->arguments();
-  if (args->length() != 2) return false;
-
-  VariableProxy* arg_two = args->at(1)->AsVariableProxy();
-  if (arg_two == NULL || !arg_two->var()->IsStackAllocated()) return false;
-  HValue* arg_two_value = LookupAndMakeLive(arg_two->var());
-  if (!arg_two_value->CheckFlag(HValue::kIsArguments)) return false;
-
-  // Found pattern f.apply(receiver, arguments).
-  CHECK_ALIVE_OR_RETURN(VisitForValue(args->at(0)), true);
+  CHECK_ALIVE(VisitForValue(args->at(0)));
   HValue* receiver = Pop();  // receiver
   HValue* function = Pop();  // f
   Drop(1);  // apply
 
+  Handle<Map> function_map = expr->GetReceiverTypes()->first();
   HValue* checked_function = AddCheckMap(function, function_map);
 
   if (function_state()->outer() == NULL) {
     HInstruction* elements = Add<HArgumentsElements>(false);
     HInstruction* length = Add<HArgumentsLength>(elements);
     HValue* wrapped_receiver = BuildWrapReceiver(receiver, checked_function);
     HInstruction* result = New<HApplyArguments>(function,
                                                 wrapped_receiver,
                                                 length,
                                                 elements);
     ast_context()->ReturnInstruction(result, expr->id());
-    return true;
   } else {
     // We are inside inlined function and we know exactly what is inside
     // arguments object. But we need to be able to materialize at deopt.
     ASSERT_EQ(environment()->arguments_environment()->parameter_count(),
               function_state()->entry()->arguments_object()->arguments_count());
     HArgumentsObject* args = function_state()->entry()->arguments_object();
     const ZoneList<HValue*>* arguments_values = args->arguments_values();
     int arguments_count = arguments_values->length();
     Push(function);
     Push(BuildWrapReceiver(receiver, checked_function));
     for (int i = 1; i < arguments_count; i++) {
       Push(arguments_values->at(i));
     }
-
-    Handle<JSFunction> known_function;
-    if (function->IsConstant() &&
-        HConstant::cast(function)->handle(isolate())->IsJSFunction()) {
-      known_function = Handle<JSFunction>::cast(
-          HConstant::cast(function)->handle(isolate()));
-      int args_count = arguments_count - 1;  // Excluding receiver.
-      if (TryInlineApply(known_function, expr, args_count)) return true;
-    }
-
-    PushArgumentsFromEnvironment(arguments_count);
-    HInvokeFunction* call = New<HInvokeFunction>(
-        function, known_function, arguments_count);
-    Drop(1);  // Function.
-    ast_context()->ReturnInstruction(call, expr->id());
-    return true;
+    HandleIndirectCall(expr, function, arguments_count, 0);
   }
 }
 
 
+// f.call(...)
+void HOptimizedGraphBuilder::BuildFunctionCall(Call* expr) {
+  HValue* function = Top();  // f
+  Handle<Map> function_map = expr->GetReceiverTypes()->first();
+  HValue* checked_function = AddCheckMap(function, function_map);
+
+  int drop_extra = 0;
+  ZoneList<Expression*>* args = expr->arguments();
+  int args_length = args->length();
+  if (args_length == 0) {
+    Drop(2);  // function and call
+    Push(function);
+    Push(BuildWrapReceiver(
+        graph()->GetConstantUndefined(), checked_function));
+    args_length = 1;
+  } else {
+    CHECK_ALIVE(VisitForValue(args->at(0)));
+    Push(BuildWrapReceiver(Pop(), checked_function));
+    for (int i = 1; i < args_length; i++) {
+      CHECK_ALIVE(VisitForValue(args->at(i)));
+    }
+    drop_extra = 1;  // drop call later
+  }
+
+  HandleIndirectCall(expr, function, args_length, drop_extra);
+}
+
+
 HValue* HOptimizedGraphBuilder::ImplicitReceiverFor(HValue* function,
                                                     Handle<JSFunction> target) {
   SharedFunctionInfo* shared = target->shared();
   if (shared->strict_mode() == SLOPPY && !shared->native()) {
     // Cannot embed a direct reference to the global proxy
     // as is it dropped on deserialization.
     CHECK(!isolate()->serializer_enabled());
     Handle<JSObject> global_receiver(
         target->context()->global_object()->global_receiver());
     return Add<HConstant>(global_receiver);
@@ skipping 241 matching lines @@
     environment()->SetExpressionStackAt(0, function);
 
     Push(receiver);
 
     if (function->IsConstant() &&
         HConstant::cast(function)->handle(isolate())->IsJSFunction()) {
       Handle<JSFunction> known_function = Handle<JSFunction>::cast(
           HConstant::cast(function)->handle(isolate()));
       expr->set_target(known_function);
 
-      if (TryCallApply(expr)) return;
+      if (TryIndirectCall(expr)) return;
       CHECK_ALIVE(VisitExpressions(expr->arguments()));
 
       Handle<Map> map = types->length() == 1 ? types->first() : Handle<Map>();
-      if (TryInlineBuiltinMethodCall(expr, receiver, map)) {
+      if (TryInlineBuiltinMethodCall(expr, known_function, map,
+                                     expr->arguments()->length())) {
         if (FLAG_trace_inlining) {
           PrintF("Inlining builtin ");
           known_function->ShortPrint();
           PrintF("\n");
         }
         return;
       }
       if (TryInlineApiMethodCall(expr, receiver, types)) return;
 
       // Wrap the receiver if necessary.
@@ skipping 3461 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal