[interpreter] Add fast path for dynamic global lookups

src/compiler/bytecode-graph-builder.cc

Index: src/compiler/bytecode-graph-builder.cc
diff --git a/src/compiler/bytecode-graph-builder.cc b/src/compiler/bytecode-graph-builder.cc
index c03b8962c58c39f28fcb1aa9d9a4c0569c5acae5..7c87e475e215fd2bae2ebbbea678bd2968732645 100644
--- a/src/compiler/bytecode-graph-builder.cc
+++ b/src/compiler/bytecode-graph-builder.cc
@@ -915,6 +915,33 @@ void BytecodeGraphBuilder::VisitLdaLookupContextSlotInsideTypeof() {
   BuildLdaLookupContextSlot(TypeofMode::INSIDE_TYPEOF);
 }
 
+void BytecodeGraphBuilder::BuildLdaLookupGlobalSlot(TypeofMode typeof_mode) {
+  // TODO(leszeks): Build the fast path here

[rmcilroy, 2016/09/19 09:04:29]

fullstops on comments.

[Leszek Swirski, 2016/09/19 10:34:51]

Damn it. Done.

+
+  // Slow path, do a runtime load lookup
+  {
+    FrameStateBeforeAndAfter states(this);
+
+    Node* name =
+        jsgraph()->Constant(bytecode_iterator().GetConstantForIndexOperand(0));
+
+    const Operator* op =
+        javascript()->CallRuntime(typeof_mode == TypeofMode::NOT_INSIDE_TYPEOF
+                                      ? Runtime::kLoadLookupSlot
+                                      : Runtime::kLoadLookupSlotInsideTypeof);
+    Node* value = NewNode(op, name);
+    environment()->BindAccumulator(value, &states);
+  }
+}
+
+void BytecodeGraphBuilder::VisitLdaLookupGlobalSlot() {
+  BuildLdaLookupGlobalSlot(TypeofMode::NOT_INSIDE_TYPEOF);
+}
+
+void BytecodeGraphBuilder::VisitLdaLookupGlobalSlotInsideTypeof() {
+  BuildLdaLookupGlobalSlot(TypeofMode::INSIDE_TYPEOF);
+}
+
 void BytecodeGraphBuilder::BuildStaLookupSlot(LanguageMode language_mode) {
   FrameStateBeforeAndAfter states(this);
   Node* value = environment()->LookupAccumulator();