Reapply descriptor array sharing.
This reverts commit 12669
Review URL: https://chromiumcodereview.appspot.com/11093026
git-svn-id: http://v8.googlecode.com/svn/trunk@12683 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 1b0f2fa..6759b19 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -2920,19 +2920,36 @@
Register temp = descriptors;
movq(temp, FieldOperand(map, Map::kTransitionsOrBackPointerOffset));
- Label ok, fail;
+ Label ok, fail, load_from_back_pointer;
CheckMap(temp,
isolate()->factory()->fixed_array_map(),
&fail,
DONT_DO_SMI_CHECK);
- movq(descriptors, FieldOperand(temp, TransitionArray::kDescriptorsOffset));
+ movq(temp, FieldOperand(temp, TransitionArray::kDescriptorsPointerOffset));
+ movq(descriptors, FieldOperand(temp, JSGlobalPropertyCell::kValueOffset));
jmp(&ok);
+
bind(&fail);
+ CompareRoot(temp, Heap::kUndefinedValueRootIndex);
+ j(not_equal, &load_from_back_pointer, Label::kNear);
Move(descriptors, isolate()->factory()->empty_descriptor_array());
+ jmp(&ok);
+
+ bind(&load_from_back_pointer);
+ movq(temp, FieldOperand(temp, Map::kTransitionsOrBackPointerOffset));
+ movq(temp, FieldOperand(temp, TransitionArray::kDescriptorsPointerOffset));
+ movq(descriptors, FieldOperand(temp, JSGlobalPropertyCell::kValueOffset));
+
bind(&ok);
}
+void MacroAssembler::NumberOfOwnDescriptors(Register dst, Register map) {
+ movq(dst, FieldOperand(map, Map::kBitField3Offset));
+ DecodeField<Map::NumberOfOwnDescriptorsBits>(dst);
+}
+
+
void MacroAssembler::EnumLength(Register dst, Register map) {
STATIC_ASSERT(Map::EnumLengthBits::kShift == 0);
movq(dst, FieldOperand(map, Map::kBitField3Offset));