Do not pass the global object as the receiver to strict-mode and

src/ia32/full-codegen-ia32.cc

 // Copyright 2011 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 3514 matching lines @@
   __ bind(&done);
   __ mov(eax, result_operand);
   // Drop temp values from the stack, and restore context register.
   __ add(Operand(esp), Immediate(3 * kPointerSize));
 
   __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
   context()->Plug(eax);
 }
 
 
+void FullCodeGenerator::EmitIsNativeOrStrictMode(ZoneList<Expression*>* args) {
+  ASSERT(args->length() == 1);
+
+  // Load the function into eax.
+  VisitForAccumulatorValue(args->at(0));
+
+  // Prepare for the test.
+  Label materialize_true, materialize_false;
+  Label* if_true = NULL;
+  Label* if_false = NULL;
+  Label* fall_through = NULL;
+  context()->PrepareTest(&materialize_true, &materialize_false,
+                         &if_true, &if_false, &fall_through);
+
+  // Test for strict mode function.
+  __ mov(ecx, FieldOperand(eax, JSFunction::kSharedFunctionInfoOffset));

[Rico, 2011/06/30 06:41:25]

I know that we explicitly check for this at the call sites (in array.js and
string.js). But shouldn't we have a check for what we actually have in eax to
guarantee that it is a JSFunction.

[Mads Ager (chromium), 2011/06/30 12:28:10]

We explicitly have checks before. We will then go on and use %_CallFunction
which does not check either.

+  __ test_b(FieldOperand(ecx, SharedFunctionInfo::kStrictModeByteOffset),
+            1 << SharedFunctionInfo::kStrictModeBitWithinByte);
+  __ j(not_equal, if_true);
+
+  // Test for native function.
+  __ test_b(FieldOperand(ecx, SharedFunctionInfo::kNativeByteOffset),
+            1 << SharedFunctionInfo::kNativeBitWithinByte);
+  __ j(not_equal, if_true);

[Rico, 2011/06/30 06:41:25]

You could consider having just one test instructions (non-byte version) with (1
<< SharedFunctionInfo::kNative & 1 << SharedFunctionInfo::kStrictModeFunction)

[Mads Ager (chromium), 2011/06/30 12:28:10]

We could. This code is similar to what we do in apply. I'll keep them the same
for now and we can see if it makes a performance difference. I don't think it
will.

+
+  // Not native or strict-mode function.
+  __ jmp(if_false);
+
+  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  context()->Plug(if_true, if_false);
+}
+
+
 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   Handle<String> name = expr->name();
   if (name->length() > 0 && name->Get(0) == '_') {
     Comment cmnt(masm_, "[ InlineRuntimeCall");
     EmitInlineRuntimeCall(expr);
     return;
   }
 
   Comment cmnt(masm_, "[ CallRuntime");
   ZoneList<Expression*>* args = expr->arguments();
@@ skipping 678 matching lines @@
   // And return.
   __ ret(0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32