Load the global proxy from the context of the target function.

src/arm/builtins-arm.cc

 // Copyright 2012 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 16 matching lines @@
 
 #include "v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "codegen.h"
 #include "debug.h"
 #include "deoptimizer.h"
 #include "full-codegen.h"
 #include "runtime.h"
+#include "stub-cache.h"
 
 namespace v8 {
 namespace internal {
 
 
 #define __ ACCESS_MASM(masm)
 
 
 void Builtins::Generate_Adaptor(MacroAssembler* masm,
                                 CFunctionId id,
@@ skipping 1020 matching lines @@
     }
 
     // Restore the function to r1, and the flag to r4.
     __ ldr(r1, MemOperand(sp, r0, LSL, kPointerSizeLog2));
     __ mov(r4, Operand::Zero());
     __ jmp(&patch_receiver);
 
     // Use the global receiver object from the called function as the
     // receiver.
     __ bind(&use_global_receiver);
-    const int kGlobalIndex =
-        Context::kHeaderSize + Context::GLOBAL_OBJECT_INDEX * kPointerSize;
-    __ ldr(r2, FieldMemOperand(cp, kGlobalIndex));
-    __ ldr(r2, FieldMemOperand(r2, GlobalObject::kNativeContextOffset));
-    __ ldr(r2, FieldMemOperand(r2, kGlobalIndex));
-    __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalReceiverOffset));
+  __ ldr(r2, ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX));

[dcarney, 2013/12/26 13:35:52]

here and below we load from the correct context directly. for the other
architectures, we're loading from the function via FetchGlobalProxy, but the
function isn't any more in a register here. maybe the other arches should be
like this one?

+  __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalReceiverOffset));
 
     __ bind(&patch_receiver);
     __ add(r3, sp, Operand(r0, LSL, kPointerSizeLog2));
     __ str(r2, MemOperand(r3, -kPointerSize));
 
     __ jmp(&shift_arguments);
   }
 
   // 3b. Check for function proxy.
   __ bind(&slow);
@@ skipping 170 matching lines @@
 
     // Convert the receiver to a regular object.
     // r0: receiver
     __ bind(&call_to_object);
     __ push(r0);
     __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
     __ b(&push_receiver);
 
     // Use the current global receiver object as the receiver.
     __ bind(&use_global_receiver);
-    const int kGlobalOffset =
-        Context::kHeaderSize + Context::GLOBAL_OBJECT_INDEX * kPointerSize;
-    __ ldr(r0, FieldMemOperand(cp, kGlobalOffset));
-    __ ldr(r0, FieldMemOperand(r0, GlobalObject::kNativeContextOffset));
-    __ ldr(r0, FieldMemOperand(r0, kGlobalOffset));
+    __ ldr(r0, ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX));
     __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalReceiverOffset));
 
     // Push the receiver.
     // r0: receiver
     __ bind(&push_receiver);
     __ push(r0);
 
     // Copy all arguments from the array to the stack.
     Label entry, loop;
     __ ldr(r0, MemOperand(fp, kIndexOffset));
@@ skipping 185 matching lines @@
   __ bind(&dont_adapt_arguments);
   __ Jump(r3);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM