Revision: 4279
Author: [email protected]
Date: Thu Mar 25 07:20:56 2010
Log: Slightly faster variant of Array.push.
Review URL: http://codereview.chromium.org/1265003
http://code.google.com/p/v8/source/detail?r=4279
Modified:
/branches/bleeding_edge/src/ia32/stub-cache-ia32.cc
=======================================
--- /branches/bleeding_edge/src/ia32/stub-cache-ia32.cc Tue Mar 23 07:33:42
2010
+++ /branches/bleeding_edge/src/ia32/stub-cache-ia32.cc Thu Mar 25 07:20:56
2010
@@ -1251,8 +1251,7 @@
__ 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 @@
__ 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 @@
// 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 @@
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);
}
--
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