Strict mode function entry (Function.prototype.call/apply)

src/ia32/builtins-ia32.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
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 //     * Redistributions in binary form must reproduce the above
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@@ skipping 571 matching lines @@
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
   __ j(not_equal, &non_function, not_taken);
 
 
   // 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));
 
+    // 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);
 
     __ 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.
@@ skipping 127 matching lines @@
   __ push(Immediate(0));  // index
 
   // Change context eagerly to get the right global object if
   // necessary.
   __ 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));
+
+  // 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());
   __ 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.
@@ skipping 817 matching lines @@
   Deoptimizer::EntryGenerator generator(masm, Deoptimizer::OSR);
   generator.Generate();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32