[libcxx-commits] [libcxx] [libc++] Optimize {set, map}::{lower, upper}_bound (PR #161366)
Nikolas Klauser via libcxx-commits
libcxx-commits at lists.llvm.org
Wed Oct 8 04:14:52 PDT 2025
https://github.com/philnik777 updated https://github.com/llvm/llvm-project/pull/161366
>From 7ee59ec131965a9489ac3ccabd0cbb4ecefc0d30 Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Tue, 30 Sep 2025 13:02:09 +0200
Subject: [PATCH] [libc++] Optimize {set,map}::{lower,upper}_bound
---
libcxx/include/__tree | 105 ++++++++++++++++++++++++++++++++----------
libcxx/include/map | 50 +++++++++++++-------
libcxx/include/set | 50 +++++++++++++-------
3 files changed, 149 insertions(+), 56 deletions(-)
diff --git a/libcxx/include/__tree b/libcxx/include/__tree
index ef960d481cb7b..d7d074a00f555 100644
--- a/libcxx/include/__tree
+++ b/libcxx/include/__tree
@@ -1166,32 +1166,87 @@ public:
template <class _Key>
_LIBCPP_HIDE_FROM_ABI size_type __count_multi(const _Key& __k) const;
+ template <bool _LowerBound, class _Key>
+ _LIBCPP_HIDE_FROM_ABI __end_node_pointer __lower_upper_bound_unique_impl(const _Key& __v) const {
+ auto __rt = __root();
+ auto __result = __end_node();
+ auto __comp = __lazy_synth_three_way_comparator<_Compare, _Key, value_type>(value_comp());
+ while (__rt != nullptr) {
+ auto __comp_res = __comp(__v, __rt->__get_value());
+
+ if (__comp_res.__less()) {
+ __result = static_cast<__end_node_pointer>(__rt);
+ __rt = static_cast<__node_pointer>(__rt->__left_);
+ } else if (__comp_res.__greater()) {
+ __rt = static_cast<__node_pointer>(__rt->__right_);
+ } else if _LIBCPP_CONSTEXPR (_LowerBound) {
+ return static_cast<__end_node_pointer>(__rt);
+ } else {
+ return __rt->__right_ ? static_cast<__end_node_pointer>(std::__tree_min(__rt->__right_)) : __result;
+ }
+ }
+ return __result;
+ }
+
+ template <class _Key>
+ _LIBCPP_HIDE_FROM_ABI iterator __lower_bound_unique(const _Key& __v) {
+ return iterator(__lower_upper_bound_unique_impl<true>(__v));
+ }
+
template <class _Key>
- _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _Key& __v) {
- return __lower_bound(__v, __root(), __end_node());
+ _LIBCPP_HIDE_FROM_ABI const_iterator __lower_bound_unique(const _Key& __v) const {
+ return const_iterator(__lower_upper_bound_unique_impl<true>(__v));
}
+
template <class _Key>
- _LIBCPP_HIDE_FROM_ABI iterator __lower_bound(const _Key& __v, __node_pointer __root, __end_node_pointer __result);
+ _LIBCPP_HIDE_FROM_ABI iterator __upper_bound_unique(const _Key& __v) {
+ return iterator(__lower_upper_bound_unique_impl<false>(__v));
+ }
+
template <class _Key>
- _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _Key& __v) const {
- return __lower_bound(__v, __root(), __end_node());
+ _LIBCPP_HIDE_FROM_ABI const_iterator __upper_bound_unique(const _Key& __v) const {
+ return iterator(__lower_upper_bound_unique_impl<false>(__v));
}
+
+private:
+ template <class _Key>
+ _LIBCPP_HIDE_FROM_ABI iterator
+ __lower_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result);
+
template <class _Key>
_LIBCPP_HIDE_FROM_ABI const_iterator
- __lower_bound(const _Key& __v, __node_pointer __root, __end_node_pointer __result) const;
+ __lower_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result) const;
+
+public:
+ template <class _Key>
+ _LIBCPP_HIDE_FROM_ABI iterator __lower_bound_multi(const _Key& __v) {
+ return __lower_bound_multi(__v, __root(), __end_node());
+ }
template <class _Key>
- _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _Key& __v) {
- return __upper_bound(__v, __root(), __end_node());
+ _LIBCPP_HIDE_FROM_ABI const_iterator __lower_bound_multi(const _Key& __v) const {
+ return __lower_bound_multi(__v, __root(), __end_node());
}
+
template <class _Key>
- _LIBCPP_HIDE_FROM_ABI iterator __upper_bound(const _Key& __v, __node_pointer __root, __end_node_pointer __result);
+ _LIBCPP_HIDE_FROM_ABI iterator __upper_bound_multi(const _Key& __v) {
+ return __upper_bound_multi(__v, __root(), __end_node());
+ }
+
template <class _Key>
- _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _Key& __v) const {
- return __upper_bound(__v, __root(), __end_node());
+ _LIBCPP_HIDE_FROM_ABI const_iterator __upper_bound_multi(const _Key& __v) const {
+ return __upper_bound_multi(__v, __root(), __end_node());
}
+
+private:
+ template <class _Key>
+ _LIBCPP_HIDE_FROM_ABI iterator
+ __upper_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result);
+
template <class _Key>
_LIBCPP_HIDE_FROM_ABI const_iterator
- __upper_bound(const _Key& __v, __node_pointer __root, __end_node_pointer __result) const;
+ __upper_bound_multi(const _Key& __v, __node_pointer __root, __end_node_pointer __result) const;
+
+public:
template <class _Key>
_LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> __equal_range_unique(const _Key& __k);
template <class _Key>
@@ -2100,16 +2155,16 @@ __tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const {
__rt = static_cast<__node_pointer>(__rt->__right_);
else
return std::distance(
- __lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__end_node_pointer>(__rt)),
- __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
+ __lower_bound_multi(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__end_node_pointer>(__rt)),
+ __upper_bound_multi(__k, static_cast<__node_pointer>(__rt->__right_), __result));
}
return 0;
}
template <class _Tp, class _Compare, class _Allocator>
template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v, __node_pointer __root, __end_node_pointer __result) {
+typename __tree<_Tp, _Compare, _Allocator>::iterator __tree<_Tp, _Compare, _Allocator>::__lower_bound_multi(
+ const _Key& __v, __node_pointer __root, __end_node_pointer __result) {
while (__root != nullptr) {
if (!value_comp()(__root->__get_value(), __v)) {
__result = static_cast<__end_node_pointer>(__root);
@@ -2122,7 +2177,7 @@ __tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v, __node_pointer
template <class _Tp, class _Compare, class _Allocator>
template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare, _Allocator>::__lower_bound(
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare, _Allocator>::__lower_bound_multi(
const _Key& __v, __node_pointer __root, __end_node_pointer __result) const {
while (__root != nullptr) {
if (!value_comp()(__root->__get_value(), __v)) {
@@ -2136,8 +2191,8 @@ typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare,
template <class _Tp, class _Compare, class _Allocator>
template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v, __node_pointer __root, __end_node_pointer __result) {
+typename __tree<_Tp, _Compare, _Allocator>::iterator __tree<_Tp, _Compare, _Allocator>::__upper_bound_multi(
+ const _Key& __v, __node_pointer __root, __end_node_pointer __result) {
while (__root != nullptr) {
if (value_comp()(__v, __root->__get_value())) {
__result = static_cast<__end_node_pointer>(__root);
@@ -2150,7 +2205,7 @@ __tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v, __node_pointer
template <class _Tp, class _Compare, class _Allocator>
template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare, _Allocator>::__upper_bound(
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator __tree<_Tp, _Compare, _Allocator>::__upper_bound_multi(
const _Key& __v, __node_pointer __root, __end_node_pointer __result) const {
while (__root != nullptr) {
if (value_comp()(__v, __root->__get_value())) {
@@ -2226,8 +2281,9 @@ __tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) {
} else if (__comp_res.__greater())
__rt = static_cast<__node_pointer>(__rt->__right_);
else
- return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__end_node_pointer>(__rt)),
- __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
+ return _Pp(
+ __lower_bound_multi(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__end_node_pointer>(__rt)),
+ __upper_bound_multi(__k, static_cast<__node_pointer>(__rt->__right_), __result));
}
return _Pp(iterator(__result), iterator(__result));
}
@@ -2249,8 +2305,9 @@ __tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const {
} else if (__comp_res.__greater())
__rt = static_cast<__node_pointer>(__rt->__right_);
else
- return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__end_node_pointer>(__rt)),
- __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
+ return _Pp(
+ __lower_bound_multi(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__end_node_pointer>(__rt)),
+ __upper_bound_multi(__k, static_cast<__node_pointer>(__rt->__right_), __result));
}
return _Pp(const_iterator(__result), const_iterator(__result));
}
diff --git a/libcxx/include/map b/libcxx/include/map
index 035f913bd3497..3ff849afcde09 100644
--- a/libcxx/include/map
+++ b/libcxx/include/map
@@ -1300,38 +1300,48 @@ public:
}
# endif // _LIBCPP_STD_VER >= 20
- _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.lower_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const { return __tree_.lower_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.__lower_bound_unique(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const {
+ return __tree_.__lower_bound_unique(__k);
+ }
+
+ // The transparent versions of the lookup functions use the _multi version, since a non-element key is allowed to
+ // match multiple elements.
# if _LIBCPP_STD_VER >= 14
template <typename _K2,
enable_if_t<__is_transparent_v<_Compare, _K2> || __is_transparently_comparable_v<_Compare, key_type, _K2>,
int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _K2& __k) {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
template <typename _K2,
enable_if_t<__is_transparent_v<_Compare, _K2> || __is_transparently_comparable_v<_Compare, key_type, _K2>,
int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _K2& __k) const {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
# endif
- _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.upper_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const { return __tree_.upper_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.__upper_bound_unique(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const {
+ return __tree_.__upper_bound_unique(__k);
+ }
+
# if _LIBCPP_STD_VER >= 14
template <typename _K2,
enable_if_t<__is_transparent_v<_Compare, _K2> || __is_transparently_comparable_v<_Compare, key_type, _K2>,
int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _K2& __k) {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
template <typename _K2,
enable_if_t<__is_transparent_v<_Compare, _K2> || __is_transparently_comparable_v<_Compare, key_type, _K2>,
int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _K2& __k) const {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
# endif
@@ -1871,30 +1881,38 @@ public:
}
# endif // _LIBCPP_STD_VER >= 20
- _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.lower_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const { return __tree_.lower_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.__lower_bound_multi(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const {
+ return __tree_.__lower_bound_multi(__k);
+ }
+
# if _LIBCPP_STD_VER >= 14
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _K2& __k) {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _K2& __k) const {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
# endif
- _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.upper_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const { return __tree_.upper_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.__upper_bound_multi(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const {
+ return __tree_.__upper_bound_multi(__k);
+ }
+
# if _LIBCPP_STD_VER >= 14
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _K2& __k) {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _K2& __k) const {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
# endif
diff --git a/libcxx/include/set b/libcxx/include/set
index 4203c69b55c84..59ed0155c1def 100644
--- a/libcxx/include/set
+++ b/libcxx/include/set
@@ -849,30 +849,40 @@ public:
}
# endif // _LIBCPP_STD_VER >= 20
- _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.lower_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const { return __tree_.lower_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.__lower_bound_unique(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const {
+ return __tree_.__lower_bound_unique(__k);
+ }
+
+ // The transparent versions of the lookup functions use the _multi version, since a non-element key is allowed to
+ // match multiple elements.
# if _LIBCPP_STD_VER >= 14
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _K2& __k) {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _K2& __k) const {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
# endif
- _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.upper_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const { return __tree_.upper_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.__upper_bound_unique(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const {
+ return __tree_.__upper_bound_unique(__k);
+ }
+
# if _LIBCPP_STD_VER >= 14
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _K2& __k) {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _K2& __k) const {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
# endif
@@ -1301,30 +1311,38 @@ public:
}
# endif // _LIBCPP_STD_VER >= 20
- _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.lower_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const { return __tree_.lower_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.__lower_bound_multi(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const {
+ return __tree_.__lower_bound_multi(__k);
+ }
+
# if _LIBCPP_STD_VER >= 14
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _K2& __k) {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _K2& __k) const {
- return __tree_.lower_bound(__k);
+ return __tree_.__lower_bound_multi(__k);
}
# endif
- _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.upper_bound(__k); }
- _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const { return __tree_.upper_bound(__k); }
+ _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.__upper_bound_multi(__k); }
+
+ _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const {
+ return __tree_.__upper_bound_multi(__k);
+ }
+
# if _LIBCPP_STD_VER >= 14
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _K2& __k) {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
_LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _K2& __k) const {
- return __tree_.upper_bound(__k);
+ return __tree_.__upper_bound_multi(__k);
}
# endif
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