Add support for global variable references in toplevel code. We use...

src/x64/fast-codegen-x64.cc

 // Copyright 2009 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 128 matching lines @@
   for (int i = 0; i < kPadding; ++i) {
     masm_->int3();
   }
 #endif
 }
 
 
 void FastCodeGenerator::VisitVariableProxy(VariableProxy* expr) {
   Comment cmnt(masm_, "[ VariableProxy");
   Expression* rewrite = expr->var()->rewrite();
-  ASSERT(rewrite != NULL);
+  if (rewrite == NULL) {

[fschneider, 2009/10/20 14:16:17]

Insert a comment here:

Comment cmnt(masm_, "[Load from global property");

+    // Reference to a global variable, use inline caching. Variable
+    // name is passed in ecx and the global object on the stack.
+    __ push(CodeGenerator::GlobalObject());
+    __ Move(rcx, expr->name());
+    Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
+    __ Call(ic, RelocInfo::CODE_TARGET_CONTEXT);
 
-  Slot* slot = rewrite->AsSlot();
-  ASSERT(slot != NULL);
-  { Comment cmnt(masm_, "[ Slot");
+    // A test rax instruction following the call is used by the IC to
+    // indicate that the inobject property case was inlined.  Ensure there
+    // is no test rax instruction here.
+    if (expr->location().is_temporary()) {
+      // Replace the global object with the result.
+      __ movq(Operand(rsp, 0), rax);
+    } else {
+      ASSERT(expr->location().is_nowhere());
+      __ pop(rax);
+    }
+
+  } else {
+    // Reference to a local or parameter slot.
+    Comment cmnt(masm_, "[ Slot");
+    Slot* slot = rewrite->AsSlot();
+    ASSERT(slot != NULL);
     if (expr->location().is_temporary()) {
       __ push(Operand(rbp, SlotOffset(slot)));
     } else {
       ASSERT(expr->location().is_nowhere());
     }
   }
 }
 
 
 void FastCodeGenerator::VisitAssignment(Assignment* expr) {
@@ skipping 57 matching lines @@
       if (destination.is_temporary()) {
         // Case 'temp <- (var = constant)'.  Save result.
         __ push(kScratchRegister);
       }
     }
   }
 }
 
 
 } }  // namespace v8::internal