Make sure that NormalizeElements and ShouldConvertToFastElements are based on the same values

BUG=v8:4518
LOG=n

Review URL: https://codereview.chromium.org/1472293002

Cr-Commit-Position: refs/heads/master@{#32265}
This commit is contained in:
verwaest 2015-11-25 03:46:36 -08:00 committed by Commit bot
parent 3d004eeab2
commit 066747ea05
2 changed files with 13 additions and 6 deletions

View File

@ -1227,13 +1227,18 @@ class FastElementsAccessor
}
int num_used = 0;
for (int i = 0; i < backing_store->length(); ++i) {
if (!backing_store->is_the_hole(i)) ++num_used;
// Bail out early if more than 1/4 is used.
if (4 * num_used > backing_store->length()) break;
}
if (4 * num_used <= backing_store->length()) {
JSObject::NormalizeElements(obj);
if (!backing_store->is_the_hole(i)) {
++num_used;
// Bail out if a number dictionary wouldn't be able to save at least
// 75% space.
if (4 * SeededNumberDictionary::ComputeCapacity(num_used) *
SeededNumberDictionary::kEntrySize >
backing_store->length()) {
return;
}
}
}
JSObject::NormalizeElements(obj);
}
}

View File

@ -14646,6 +14646,8 @@ static bool ShouldConvertToFastElements(JSObject* object,
uint32_t dictionary_size = static_cast<uint32_t>(dictionary->Capacity()) *
SeededNumberDictionary::kEntrySize;
// Turn fast if the dictionary only saves 50% space.
return 2 * dictionary_size >= *new_capacity;
}