Draft of ES5 fix to Function.prototype.call and apply

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index 0a3e0930560bf5f656a7c6768852bfb6157d2c80..f1c2944de604f8ef6f55b14f677615f266630abb 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -582,65 +582,16 @@ void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
   __ j(not_equal, &non_function, not_taken);
 
+  // Change context eagerly in case we need the global receiver.
+  __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
 
-  // 3a. Patch the first argument if necessary when calling a function.
   Label shift_arguments;
-  { Label convert_to_object, use_global_receiver, patch_receiver;
-    // Change context eagerly in case we need the global receiver.
-    __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
-
-    __ mov(ebx, Operand(esp, eax, times_4, 0));  // First argument.
-    __ test(ebx, Immediate(kSmiTagMask));
-    __ j(zero, &convert_to_object);
-
-    __ cmp(ebx, Factory::null_value());
-    __ j(equal, &use_global_receiver);
-    __ cmp(ebx, Factory::undefined_value());
-    __ j(equal, &use_global_receiver);
-
-    // We don't use IsObjectJSObjectType here because we jump on success.
-    __ mov(ecx, FieldOperand(ebx, HeapObject::kMapOffset));
-    __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
-    __ sub(Operand(ecx), Immediate(FIRST_JS_OBJECT_TYPE));
-    __ cmp(ecx, LAST_JS_OBJECT_TYPE - FIRST_JS_OBJECT_TYPE);
-    __ j(below_equal, &shift_arguments);
-
-    __ bind(&convert_to_object);
-    __ EnterInternalFrame();  // In order to preserve argument count.
-    __ SmiTag(eax);
-    __ push(eax);
+  __ jmp(&shift_arguments);
 
-    __ push(ebx);
-    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
-    __ mov(ebx, eax);
-
-    __ pop(eax);
-    __ SmiUntag(eax);
-    __ LeaveInternalFrame();
-    // Restore the function to edi.
-    __ mov(edi, Operand(esp, eax, times_4, 1 * kPointerSize));
-    __ 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_INDEX * kPointerSize;
-    __ mov(ebx, FieldOperand(esi, kGlobalIndex));
-    __ mov(ebx, FieldOperand(ebx, GlobalObject::kGlobalContextOffset));
-    __ mov(ebx, FieldOperand(ebx, kGlobalIndex));
-    __ mov(ebx, FieldOperand(ebx, GlobalObject::kGlobalReceiverOffset));
-
-    __ bind(&patch_receiver);
-    __ mov(Operand(esp, eax, times_4, 0), ebx);
-
-    __ jmp(&shift_arguments);
-  }
-
-  // 3b. Patch the first argument when calling a non-function.  The
-  //     CALL_NON_FUNCTION builtin expects the non-function callee as
-  //     receiver, so overwrite the first argument which will ultimately
-  //     become the receiver.
+  // 3. Patch the first argument when calling a non-function.  The
+  //    CALL_NON_FUNCTION builtin expects the non-function callee as
+  //    receiver, so overwrite the first argument which will ultimately
+  //    become the receiver.
   __ bind(&non_function);
   __ mov(Operand(esp, eax, times_4, 0), edi);
   // Clear edi to indicate a non-function being called.
@@ -733,43 +684,8 @@ void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
   __ mov(edi, Operand(ebp, 4 * kPointerSize));
   __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
 
-  // Compute the receiver.
-  Label call_to_object, use_global_receiver, push_receiver;
-  __ mov(ebx, Operand(ebp, 3 * kPointerSize));
-  __ test(ebx, Immediate(kSmiTagMask));
-  __ j(zero, &call_to_object);
-  __ cmp(ebx, Factory::null_value());
-  __ j(equal, &use_global_receiver);
-  __ cmp(ebx, Factory::undefined_value());
-  __ j(equal, &use_global_receiver);
-
-  // If given receiver is already a JavaScript object then there's no
-  // reason for converting it.
-  // We don't use IsObjectJSObjectType here because we jump on success.
-  __ mov(ecx, FieldOperand(ebx, HeapObject::kMapOffset));
-  __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
-  __ sub(Operand(ecx), Immediate(FIRST_JS_OBJECT_TYPE));
-  __ cmp(ecx, LAST_JS_OBJECT_TYPE - FIRST_JS_OBJECT_TYPE);
-  __ j(below_equal, &push_receiver);
-
-  // Convert the receiver to an object.
-  __ bind(&call_to_object);
-  __ push(ebx);
-  __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
-  __ mov(ebx, Operand(eax));
-  __ jmp(&push_receiver);
-
-  // Use the current global receiver object as the receiver.
-  __ bind(&use_global_receiver);
-  const int kGlobalOffset =
-      Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
-  __ mov(ebx, FieldOperand(esi, kGlobalOffset));
-  __ mov(ebx, FieldOperand(ebx, GlobalObject::kGlobalContextOffset));
-  __ mov(ebx, FieldOperand(ebx, kGlobalOffset));
-  __ mov(ebx, FieldOperand(ebx, GlobalObject::kGlobalReceiverOffset));
-
   // Push the receiver.
-  __ bind(&push_receiver);
+  __ mov(ebx, Operand(ebp, 3 * kPointerSize));
   __ push(ebx);
 
   // Copy all arguments from the array to the stack.