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Also use binary search to search through valid entries.

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Review URL: https://chromiumcodereview.appspot.com/11028056

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12690 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
verwaest@chromium.org 2012-10-10 14:48:07 +00:00
parent c2a9d49393
commit e5620d5a58
1 changed files with 14 additions and 6 deletions
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20
src/objects-inl.h
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@ -1915,8 +1915,8 @@ void DescriptorArray::SetNumberOfDescriptors(int number_of_descriptors) {
// Perform a binary search in a fixed array. Low and high are entry indices. If
// there are three entries in this array it should be called with low=0 and
// high=2.
template<typename T>
int BinarySearch(T* array, String* name, int low, int high) {
template<SearchMode search_mode, typename T>
int BinarySearch(T* array, String* name, int low, int high, int valid_entries) {
uint32_t hash = name->Hash();
int limit = high;
@ -1938,12 +1938,18 @@ int BinarySearch(T* array, String* name, int low, int high) {
int sort_index = array->GetSortedKeyIndex(low);
String* entry = array->GetKey(sort_index);
if (entry->Hash() != hash) break;
if (entry->Equals(name)) return sort_index;
if (entry->Equals(name)) {
if (search_mode == ALL_ENTRIES || sort_index < valid_entries) {
return sort_index;
}
return T::kNotFound;
}
}
return T::kNotFound;
}
// Perform a linear search in this fixed array. len is the number of entry
// indices that are valid.
template<SearchMode search_mode, typename T>
@ -1982,13 +1988,15 @@ int Search(T* array, String* name, int valid_entries) {
// Fast case: do linear search for small arrays.
const int kMaxElementsForLinearSearch = 8;
if (search_mode == VALID_ENTRIES ||
(search_mode == ALL_ENTRIES && nof < kMaxElementsForLinearSearch)) {
if ((search_mode == ALL_ENTRIES &&
nof <= kMaxElementsForLinearSearch) ||
(search_mode == VALID_ENTRIES &&
valid_entries <= (kMaxElementsForLinearSearch * 3))) {
return LinearSearch<search_mode>(array, name, nof, valid_entries);
}
// Slow case: perform binary search.
return BinarySearch(array, name, 0, nof - 1);
return BinarySearch<search_mode>(array, name, 0, nof - 1, valid_entries);
}