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Slightly faster variant of Array.push.

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Review URL: http://codereview.chromium.org/1265003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4279 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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antonm@chromium.org 2010-03-25 14:20:56 +00:00
parent f45c35ebd3
commit 5e24ffaa22
1 changed files with 7 additions and 6 deletions
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13
src/ia32/stub-cache-ia32.cc
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@ -1251,8 +1251,7 @@ Object* CallStubCompiler::CompileArrayPushCall(Object* object,
__ j(not_equal, &miss);
if (argc == 1) { // Otherwise fall through to call builtin.
Label call_builtin, exit, with_rset_update,
attempt_to_grow_elements, finish_push;
Label call_builtin, exit, with_rset_update, attempt_to_grow_elements;
// Get the array's length into eax and calculate new length.
__ mov(eax, FieldOperand(edx, JSArray::kLengthOffset));
@ -1278,8 +1277,6 @@ Object* CallStubCompiler::CompileArrayPushCall(Object* object,
__ mov(ecx, Operand(esp, argc * kPointerSize));
__ mov(Operand(edx, 0), ecx);
__ bind(&finish_push);
// Check if value is a smi.
__ test(ecx, Immediate(kSmiTagMask));
__ j(not_zero, &with_rset_update);
@ -1318,10 +1315,13 @@ Object* CallStubCompiler::CompileArrayPushCall(Object* object,
// We fit and could grow elements.
__ mov(Operand::StaticVariable(new_space_allocation_top), ecx);
__ mov(ecx, Operand(esp, argc * kPointerSize));
// Push the argument...
__ mov(Operand(edx, 0), ecx);
// ... and fill the rest with holes.
for (int i = 1; i < kAllocationDelta; i++) {
__ mov(Operand(edx, i * kPointerSize),
Immediate(Factory::undefined_value()));
Immediate(Factory::the_hole_value()));
}
// Restore receiver to edx as finish sequence assumes it's here.
@ -1332,7 +1332,8 @@ Object* CallStubCompiler::CompileArrayPushCall(Object* object,
Immediate(kAllocationDelta));
__ mov(FieldOperand(edx, JSArray::kLengthOffset), eax);
__ jmp(&finish_push);
// Elements are in new space, so no remembered set updates are necessary.
__ ret((argc + 1) * kPointerSize);
__ bind(&call_builtin);
}