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Slightly simplify slow elements conversion check.

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R=danno@chromium.org

Review URL: http://codereview.chromium.org/7460011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8700 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
vitalyr@chromium.org 2011-07-20 15:14:50 +00:00
parent c9f2a4325f
commit 013baa4164
1 changed files with 9 additions and 11 deletions
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20
src/objects.cc
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@ -7687,8 +7687,7 @@ MaybeObject* JSObject::SetElementsLength(Object* len) {
}
int min = NewElementsCapacity(old_capacity);
int new_capacity = value > min ? value : min;
if (new_capacity <= kMaxFastElementsLength ||
!ShouldConvertToSlowElements(new_capacity)) {
if (!ShouldConvertToSlowElements(new_capacity)) {
MaybeObject* result;
if (GetElementsKind() == FAST_ELEMENTS) {
result = SetFastElementsCapacityAndLength(new_capacity, value);
@ -8434,8 +8433,7 @@ MaybeObject* JSObject::SetFastElement(uint32_t index,
if ((index - length) < kMaxGap) {
// Try allocating extra space.
int new_capacity = NewElementsCapacity(index + 1);
if (new_capacity <= kMaxFastElementsLength ||
!ShouldConvertToSlowElements(new_capacity)) {
if (!ShouldConvertToSlowElements(new_capacity)) {
ASSERT(static_cast<uint32_t>(new_capacity) > index);
Object* new_elements;
MaybeObject* maybe =
@ -8617,8 +8615,7 @@ MUST_USE_RESULT MaybeObject* JSObject::SetFastDoubleElement(
if ((index - elms_length) < kMaxGap) {
// Try allocating extra space.
int new_capacity = NewElementsCapacity(index+1);
if (new_capacity <= kMaxFastElementsLength ||
!ShouldConvertToSlowElements(new_capacity)) {
if (!ShouldConvertToSlowElements(new_capacity)) {
ASSERT(static_cast<uint32_t>(new_capacity) > index);
Object* obj;
{ MaybeObject* maybe_obj =
@ -9141,21 +9138,22 @@ bool JSObject::HasDenseElements() {
bool JSObject::ShouldConvertToSlowElements(int new_capacity) {
if (new_capacity <= kMaxFastElementsLength) return false;
// Keep the array in fast case if the current backing storage is
// almost filled and if the new capacity is no more than twice the
// old capacity.
int elements_length = 0;
int old_capacity = 0;
if (elements()->map() == GetHeap()->non_strict_arguments_elements_map()) {
FixedArray* backing_store = FixedArray::cast(elements());
elements_length = FixedArray::cast(backing_store->get(1))->length();
old_capacity = FixedArray::cast(backing_store->get(1))->length();
} else if (HasFastElements()) {
elements_length = FixedArray::cast(elements())->length();
old_capacity = FixedArray::cast(elements())->length();
} else if (HasFastDoubleElements()) {
elements_length = FixedDoubleArray::cast(elements())->length();
old_capacity = FixedDoubleArray::cast(elements())->length();
} else {
UNREACHABLE();
}
return !HasDenseElements() || ((new_capacity / 2) > elements_length);
return !HasDenseElements() || ((new_capacity / 2) > old_capacity);
}