Strict mode function entry (Function.prototype.call/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..fb0171cd2b55744427f300e6979fee4d6721a049 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -589,6 +589,14 @@ void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
     // Change context eagerly in case we need the global receiver.
     __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
 
+    // Do not transform the receiver for strict mode functions.
+    __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+    __ mov(ebx, FieldOperand(ebx, SharedFunctionInfo::kCompilerHintsOffset));
+    __ test(ebx, Immediate(1 << (SharedFunctionInfo::kStrictModeFunction +
+                                 kSmiTagSize)));
+    __ j(not_equal, &shift_arguments);
+
+    // Compute the receiver in non-strict mode.
     __ mov(ebx, Operand(esp, eax, times_4, 0));  // First argument.
     __ test(ebx, Immediate(kSmiTagMask));
     __ j(zero, &convert_to_object);
@@ -736,6 +744,15 @@ void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
   // Compute the receiver.
   Label call_to_object, use_global_receiver, push_receiver;
   __ mov(ebx, Operand(ebp, 3 * kPointerSize));
+
+  // Do not transform the receiver for strict mode functions.
+  __ mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+  __ mov(ecx, FieldOperand(ecx, SharedFunctionInfo::kCompilerHintsOffset));
+  __ test(ecx, Immediate(1 << (SharedFunctionInfo::kStrictModeFunction +
+                               kSmiTagSize)));

[Lasse Reichstein, 2011/02/15 08:46:55]

You can test directly against memory, without loading into ecx first, i.e.,
 test(FieldOperand(ecx, SharedFunctionInfo::kCompilerHintsOffset),
Immediate(...));

You might also want to use a byte-test
 ASSERT_EQ(8, SharedFunctionInfo::kStrictModeFunction);
 test_b(FieldOperand(ecx, ... + 1), Immediate((1 << (...)) >> 8);
It would allow an 8-bit immediate instead of a 32-bit one.
(Ditto for X64, with the appropriate differences for encoding).

[Mads Ager (chromium), 2011/02/15 08:50:12]

If you do use the byte version, please introduce some named constants to use in
the immediate to make it readable. :-)

[Martin Maly, 2011/02/15 19:18:43]

Done.

+  __ j(not_equal, &push_receiver);
+
+  // Compute the receiver in non-strict mode.
   __ test(ebx, Immediate(kSmiTagMask));
   __ j(zero, &call_to_object);
   __ cmp(ebx, Factory::null_value());