AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

[elements] Don't duplicate overallocation of elements dict in SlowArrayConcat

Browse Source 
Bug: v8:126
Change-Id: I13d42f0dccb0899f0aad572d33501e856073db9d
Reviewed-on: https://chromium-review.googlesource.com/544968
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46179}
This commit is contained in:
Toon Verwaest 2017-06-23 13:31:02 +02:00 committed by Commit Bot
parent 66e9152fe6
commit 8cd842bf91
1 changed files with 6 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/builtins/builtins-array.cc
View File

@ -966,7 +966,7 @@ Object* Slow_ArrayConcat(BuiltinArguments* args, Handle<Object> species,
ElementsKind kind = FAST_SMI_ELEMENTS;
uint32_t estimate_result_length = 0;
uint32_t estimate_nof_elements = 0;
uint32_t estimate_nof = 0;
FOR_WITH_HANDLE_SCOPE(isolate, int, i = 0, i, i < argument_count, i++, {
Handle<Object> obj((*args)[i], isolate);
uint32_t length_estimate;
@ -994,10 +994,10 @@ Object* Slow_ArrayConcat(BuiltinArguments* args, Handle<Object> species,
} else {
estimate_result_length += length_estimate;
}
if (JSObject::kMaxElementCount - estimate_nof_elements < element_estimate) {
estimate_nof_elements = JSObject::kMaxElementCount;
if (JSObject::kMaxElementCount - estimate_nof < element_estimate) {
estimate_nof = JSObject::kMaxElementCount;
} else {
estimate_nof_elements += element_estimate;
estimate_nof += element_estimate;
}
});
@ -1005,7 +1005,7 @@ Object* Slow_ArrayConcat(BuiltinArguments* args, Handle<Object> species,
// fixed array (fast case) is more time and space-efficient than a
// dictionary.
bool fast_case = is_array_species &&
(estimate_nof_elements * 2) >= estimate_result_length &&
(estimate_nof * 2) >= estimate_result_length &&
isolate->IsIsConcatSpreadableLookupChainIntact();
if (fast_case && kind == FAST_DOUBLE_ELEMENTS) {
@ -1093,10 +1093,7 @@ Object* Slow_ArrayConcat(BuiltinArguments* args, Handle<Object> species,
storage =
isolate->factory()->NewFixedArrayWithHoles(estimate_result_length);
} else if (is_array_species) {
// TODO(126): move 25% pre-allocation logic into Dictionary::Allocate
uint32_t at_least_space_for =
estimate_nof_elements + (estimate_nof_elements >> 2);
storage = SeededNumberDictionary::New(isolate, at_least_space_for);
storage = SeededNumberDictionary::New(isolate, estimate_nof);
} else {
DCHECK(species->IsConstructor());
Handle<Object> length(Smi::kZero, isolate);