[interpreter] Add fast path for dynamic global lookups

src/interpreter/interpreter.cc

 // Copyright 2015 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/interpreter/interpreter.h"
 
 #include <fstream>
 #include <memory>
 
 #include "src/ast/prettyprinter.h"
@@ skipping 403 matching lines @@
 //
 // Stores the value of register <src> to register <dst>.
 void Interpreter::DoMov(InterpreterAssembler* assembler) {
   Node* src_index = __ BytecodeOperandReg(0);
   Node* src_value = __ LoadRegister(src_index);
   Node* dst_index = __ BytecodeOperandReg(1);
   __ StoreRegister(src_value, dst_index);
   __ Dispatch();
 }
 
-Node* Interpreter::BuildLoadGlobal(Callable ic,
+Node* Interpreter::BuildLoadGlobal(Callable ic, Node* context,
+                                   Node* feedback_slot,
                                    InterpreterAssembler* assembler) {
   typedef LoadGlobalWithVectorDescriptor Descriptor;
-  // Get the global object.
-  Node* context = __ GetContext();
 
   // Load the global via the LoadGlobalIC.
   Node* code_target = __ HeapConstant(ic.code());
-  Node* raw_slot = __ BytecodeOperandIdx(0);
-  Node* smi_slot = __ SmiTag(raw_slot);
+  Node* smi_slot = __ SmiTag(feedback_slot);
   Node* type_feedback_vector = __ LoadTypeFeedbackVector();
   return __ CallStub(ic.descriptor(), code_target, context,
                      Arg(Descriptor::kSlot, smi_slot),
                      Arg(Descriptor::kVector, type_feedback_vector));
 }
 
 // LdaGlobal <slot>
 //
 // Load the global with name in constant pool entry <name_index> into the
 // accumulator using FeedBackVector slot <slot> outside of a typeof.
 void Interpreter::DoLdaGlobal(InterpreterAssembler* assembler) {
   Callable ic =
       CodeFactory::LoadGlobalICInOptimizedCode(isolate_, NOT_INSIDE_TYPEOF);
-  Node* result = BuildLoadGlobal(ic, assembler);
+
+  Node* context = __ GetContext();
+
+  Node* raw_slot = __ BytecodeOperandIdx(0);
+  Node* result = BuildLoadGlobal(ic, context, raw_slot, assembler);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 // LdrGlobal <slot> <reg>
 //
 // Load the global with name in constant pool entry <name_index> into
 // register <reg> using FeedBackVector slot <slot> outside of a typeof.
 void Interpreter::DoLdrGlobal(InterpreterAssembler* assembler) {
   Callable ic =
       CodeFactory::LoadGlobalICInOptimizedCode(isolate_, NOT_INSIDE_TYPEOF);
-  Node* result = BuildLoadGlobal(ic, assembler);
+
+  Node* context = __ GetContext();
+
+  Node* raw_slot = __ BytecodeOperandIdx(0);
+  Node* result = BuildLoadGlobal(ic, context, raw_slot, assembler);
   Node* destination = __ BytecodeOperandReg(1);
   __ StoreRegister(result, destination);
   __ Dispatch();
 }
 
 // LdaGlobalInsideTypeof <slot>
 //
 // Load the global with name in constant pool entry <name_index> into the
 // accumulator using FeedBackVector slot <slot> inside of a typeof.
 void Interpreter::DoLdaGlobalInsideTypeof(InterpreterAssembler* assembler) {
   Callable ic =
       CodeFactory::LoadGlobalICInOptimizedCode(isolate_, INSIDE_TYPEOF);
-  Node* result = BuildLoadGlobal(ic, assembler);
+
+  Node* context = __ GetContext();
+
+  Node* raw_slot = __ BytecodeOperandIdx(0);
+  Node* result = BuildLoadGlobal(ic, context, raw_slot, assembler);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 void Interpreter::DoStaGlobal(Callable ic, InterpreterAssembler* assembler) {
   typedef StoreWithVectorDescriptor Descriptor;
   // Get the global object.
   Node* context = __ GetContext();
   Node* native_context =
       __ LoadContextSlot(context, Context::NATIVE_CONTEXT_INDEX);
@@ skipping 73 matching lines @@
   Node* context = __ LoadRegister(reg_index);
   Node* slot_index = __ BytecodeOperandIdx(1);
   Node* depth = __ BytecodeOperandUImm(2);
   Node* slot_context = __ GetContextAtDepth(context, depth);
   __ StoreContextSlot(slot_context, slot_index, value);
   __ Dispatch();
 }
 
 void Interpreter::DoLdaLookupSlot(Runtime::FunctionId function_id,
                                   InterpreterAssembler* assembler) {
-  Node* index = __ BytecodeOperandIdx(0);
-  Node* name = __ LoadConstantPoolEntry(index);
+  Node* name_index = __ BytecodeOperandIdx(0);
+  Node* name = __ LoadConstantPoolEntry(name_index);
   Node* context = __ GetContext();
   Node* result = __ CallRuntime(function_id, context, name);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 // LdaLookupSlot <name_index>
 //
 // Lookup the object with the name in constant pool entry |name_index|
 // dynamically.
@@ skipping 32 matching lines @@
   // Slow path when we have to call out to the runtime.
   __ Bind(&slowpath);
   {
     Node* name = __ LoadConstantPoolEntry(name_index);
     Node* result = __ CallRuntime(function_id, context, name);
     __ SetAccumulator(result);
     __ Dispatch();
   }
 }
 
 // LdaLookupSlot <name_index>

[Michael Starzinger, 2016/09/20 09:26:38]

nit: // LdaLookupContextSlot <name_index> <slot_index> <depth>

 //
 // Lookup the object with the name in constant pool entry |name_index|
 // dynamically.
 void Interpreter::DoLdaLookupContextSlot(InterpreterAssembler* assembler) {
   DoLdaLookupContextSlot(Runtime::kLoadLookupSlot, assembler);
 }
 
 // LdaLookupSlotInsideTypeof <name_index>

[Michael Starzinger, 2016/09/20 09:26:38]

nit: Likewise.

 //
 // Lookup the object with the name in constant pool entry |name_index|
 // dynamically without causing a NoReferenceError.
 void Interpreter::DoLdaLookupContextSlotInsideTypeof(
     InterpreterAssembler* assembler) {
   DoLdaLookupContextSlot(Runtime::kLoadLookupSlotInsideTypeof, assembler);
 }
 
+void Interpreter::DoLdaLookupGlobalSlot(Runtime::FunctionId function_id,
+                                        InterpreterAssembler* assembler) {
+  Node* context = __ GetContext();
+  Node* name_index = __ BytecodeOperandIdx(0);
+  Node* feedback_slot = __ BytecodeOperandIdx(1);
+  Node* depth = __ BytecodeOperandUImm(2);
+
+  Label slowpath(assembler, Label::kDeferred);
+
+  // Check for context extensions to allow the fast path
+  __ GotoIfHasContextExtensionUpToDepth(context, depth, &slowpath);
+
+  // Fast path does a normal load global
+  {
+    Callable ic = CodeFactory::LoadGlobalICInOptimizedCode(
+        isolate_, function_id == Runtime::kLoadLookupSlotInsideTypeof
+                      ? INSIDE_TYPEOF
+                      : NOT_INSIDE_TYPEOF);
+    Node* result = BuildLoadGlobal(ic, context, feedback_slot, assembler);
+    __ SetAccumulator(result);
+    __ Dispatch();
+  }
+
+  // Slow path when we have to call out to the runtime
+  __ Bind(&slowpath);
+  {
+    Node* name = __ LoadConstantPoolEntry(name_index);
+    Node* result = __ CallRuntime(function_id, context, name);
+    __ SetAccumulator(result);
+    __ Dispatch();
+  }
+}
+
+// LdaLookupSlot <name_index>

[Michael Starzinger, 2016/09/20 09:26:38]

nit: // LdaLookupGlobalSlot <name_index> <slot> <depth>

+//
+// Lookup the object with the name in constant pool entry |name_index|
+// dynamically.
+void Interpreter::DoLdaLookupGlobalSlot(InterpreterAssembler* assembler) {
+  DoLdaLookupGlobalSlot(Runtime::kLoadLookupSlot, assembler);
+}
+
+// LdaLookupSlotInsideTypeof <name_index>

[Michael Starzinger, 2016/09/20 09:26:38]

nit: Likewise.

+//
+// Lookup the object with the name in constant pool entry |name_index|
+// dynamically without causing a NoReferenceError.
+void Interpreter::DoLdaLookupGlobalSlotInsideTypeof(
+    InterpreterAssembler* assembler) {
+  DoLdaLookupGlobalSlot(Runtime::kLoadLookupSlotInsideTypeof, assembler);
+}
+
 void Interpreter::DoStaLookupSlot(LanguageMode language_mode,
                                   InterpreterAssembler* assembler) {
   Node* value = __ GetAccumulator();
   Node* index = __ BytecodeOperandIdx(0);
   Node* name = __ LoadConstantPoolEntry(index);
   Node* context = __ GetContext();
   Node* result = __ CallRuntime(is_strict(language_mode)
                                     ? Runtime::kStoreLookupSlot_Strict
                                     : Runtime::kStoreLookupSlot_Sloppy,
                                 context, name, value);
@@ skipping 1866 matching lines @@
   __ StoreObjectField(generator, JSGeneratorObject::kContinuationOffset,
       __ SmiTag(new_state));
   __ SetAccumulator(old_state);
 
   __ Dispatch();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8