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[regexp] Shrink results array in @@match and @@split

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Both @@match and @@split internally use dynamically growing fixed
arrays. Shrink to fit when wrapping these in a JSArray to avoid
excessive memory usage.

BUG=chromium:670205,chromium:670708

Review-Url: https://codereview.chromium.org/2556773002
Cr-Commit-Position: refs/heads/master@{#41550}
This commit is contained in:
jgruber 2016-12-07 05:05:30 -08:00 committed by Commit bot
parent 0d4219913e
commit 40e176056d
1 changed files with 28 additions and 8 deletions
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36
src/builtins/builtins-regexp.cc
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@ -1386,7 +1386,7 @@ class GrowableFixedArray {
a->Bind(&grow);
{
Node* const new_capacity = NewCapacity(a, capacity);
Node* const new_array = GrowFixedArray(capacity, new_capacity, mode);
Node* const new_array = ResizeFixedArray(length, new_capacity, mode);
var_capacity_.Bind(new_capacity);
var_array_.Bind(new_array);
@ -1407,10 +1407,28 @@ class GrowableFixedArray {
CodeStubAssembler* a = assembler_;
const ElementsKind kind = FAST_ELEMENTS;
const ParameterMode mode = CodeStubAssembler::INTPTR_PARAMETERS;
Node* const native_context = a->LoadNativeContext(context);
Node* const array_map = a->LoadJSArrayElementsMap(kind, native_context);
// Shrink to fit if necessary.
{
Label next(a);
Node* const length = var_length_.value();
Node* const capacity = var_capacity_.value();
a->GotoIf(a->WordEqual(length, capacity), &next);
Node* const array = ResizeFixedArray(length, length, mode);
var_array_.Bind(array);
var_capacity_.Bind(length);
a->Goto(&next);
a->Bind(&next);
}
Node* const result_length = a->SmiTag(length());
Node* const result = a->AllocateUninitializedJSArrayWithoutElements(
kind, array_map, result_length, nullptr);
@ -1454,14 +1472,17 @@ class GrowableFixedArray {
return new_capacity;
}
Node* GrowFixedArray(Node* const current_capacity, Node* const new_capacity,
ParameterMode mode) {
// Creates a new array with {new_capacity} and copies the first
// {element_count} elements from the current array.
Node* ResizeFixedArray(Node* const element_count, Node* const new_capacity,
ParameterMode mode) {
DCHECK(mode == CodeStubAssembler::INTPTR_PARAMETERS);
CodeStubAssembler* a = assembler_;
CSA_ASSERT(a, a->IntPtrGreaterThan(current_capacity, a->IntPtrConstant(0)));
CSA_ASSERT(a, a->IntPtrGreaterThan(new_capacity, current_capacity));
CSA_ASSERT(a, a->IntPtrGreaterThan(element_count, a->IntPtrConstant(0)));
CSA_ASSERT(a, a->IntPtrGreaterThan(new_capacity, a->IntPtrConstant(0)));
CSA_ASSERT(a, a->IntPtrGreaterThanOrEqual(new_capacity, element_count));
const ElementsKind kind = FAST_ELEMENTS;
const WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER;
@ -1471,9 +1492,8 @@ class GrowableFixedArray {
Node* const from_array = var_array_.value();
Node* const to_array =
a->AllocateFixedArray(kind, new_capacity, mode, flags);
a->CopyFixedArrayElements(kind, from_array, kind, to_array,
current_capacity, new_capacity, barrier_mode,
mode);
a->CopyFixedArrayElements(kind, from_array, kind, to_array, element_count,
new_capacity, barrier_mode, mode);
return to_array;
}