[libcxx-commits] [libcxx] 2f2fe48 - [libc++] Avoid ranges::upper_bound inside <format> (#173150)

[via libcxx-commits]

Author: Nikolas Klauser
Date: 2026-01-08T12:14:18+01:00
New Revision: 2f2fe489d76007a8c56fb02f081915737ae6a0ed

URL: https://github.com/llvm/llvm-project/commit/2f2fe489d76007a8c56fb02f081915737ae6a0ed
DIFF: https://github.com/llvm/llvm-project/commit/2f2fe489d76007a8c56fb02f081915737ae6a0ed.diff

LOG: [libc++] Avoid ranges::upper_bound inside <format> (#173150)

This reduces the time to include `<vector>` from 565ms to 452ms on my
machine.

Added: 
    

Modified: 
    libcxx/include/__format/extended_grapheme_cluster_table.h
    libcxx/include/__format/indic_conjunct_break_table.h
    libcxx/include/__format/width_estimation_table.h
    libcxx/utils/generate_extended_grapheme_cluster_table.py
    libcxx/utils/generate_indic_conjunct_break_table.py
    libcxx/utils/generate_width_estimation_table.py

Removed: 
    


################################################################################
diff  --git a/libcxx/include/__format/extended_grapheme_cluster_table.h b/libcxx/include/__format/extended_grapheme_cluster_table.h
index f76e018df7ae1..6da07862d41e6 100644
--- a/libcxx/include/__format/extended_grapheme_cluster_table.h
+++ b/libcxx/include/__format/extended_grapheme_cluster_table.h
@@ -61,7 +61,7 @@
 #ifndef _LIBCPP___FORMAT_EXTENDED_GRAPHEME_CLUSTER_TABLE_H
 #define _LIBCPP___FORMAT_EXTENDED_GRAPHEME_CLUSTER_TABLE_H
 
-#include <__algorithm/ranges_upper_bound.h>
+#include <__algorithm/upper_bound.h>
 #include <__config>
 #include <__cstddef/ptr
diff _t.h>
 #include <__iterator/access.h>
@@ -1647,7 +1647,8 @@ _LIBCPP_HIDE_FROM_ABI inline constexpr uint32_t __entries[1501] = {
   // size. Then the upper bound for code point 3 will return the entry after
   // 0x1810. After moving to the previous entry the algorithm arrives at the
   // correct entry.
-  ptr
diff _t __i = std::ranges::upper_bound(__entries, (__code_point << 11) | 0x7ffu) - __entries;
+  ptr
diff _t __i =
+      std::upper_bound(std::begin(__entries), std::end(__entries), (__code_point << 11) | 0x7ffu) - __entries;
   if (__i == 0)
     return __property::__none;
 

diff  --git a/libcxx/include/__format/indic_conjunct_break_table.h b/libcxx/include/__format/indic_conjunct_break_table.h
index f48ea625908e9..d85782d73286b 100644
--- a/libcxx/include/__format/indic_conjunct_break_table.h
+++ b/libcxx/include/__format/indic_conjunct_break_table.h
@@ -61,7 +61,7 @@
 #ifndef _LIBCPP___FORMAT_INDIC_CONJUNCT_BREAK_TABLE_H
 #define _LIBCPP___FORMAT_INDIC_CONJUNCT_BREAK_TABLE_H
 
-#include <__algorithm/ranges_upper_bound.h>
+#include <__algorithm/upper_bound.h>
 #include <__config>
 #include <__cstddef/ptr
diff _t.h>
 #include <__iterator/access.h>
@@ -531,7 +531,8 @@ _LIBCPP_HIDE_FROM_ABI inline constexpr uint32_t __entries[403] = {
   // size. Then the upper bound for code point 3 will return the entry after
   // 0x1810. After moving to the previous entry the algorithm arrives at the
   // correct entry.
-  ptr
diff _t __i = std::ranges::upper_bound(__entries, (__code_point << 11) | 0x7ffu) - __entries;
+  ptr
diff _t __i =
+      std::upper_bound(std::begin(__entries), std::end(__entries), (__code_point << 11) | 0x7ffu) - __entries;
   if (__i == 0)
     return __property::__none;
 

diff  --git a/libcxx/include/__format/width_estimation_table.h b/libcxx/include/__format/width_estimation_table.h
index 0ea0b4f413a74..ae10a77a5b980 100644
--- a/libcxx/include/__format/width_estimation_table.h
+++ b/libcxx/include/__format/width_estimation_table.h
@@ -61,9 +61,10 @@
 #ifndef _LIBCPP___FORMAT_WIDTH_ESTIMATION_TABLE_H
 #define _LIBCPP___FORMAT_WIDTH_ESTIMATION_TABLE_H
 
-#include <__algorithm/ranges_upper_bound.h>
+#include <__algorithm/upper_bound.h>
 #include <__config>
 #include <__cstddef/ptr
diff _t.h>
+#include <__iterator/access.h>
 #include <cstdint>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -255,7 +256,8 @@ inline constexpr uint32_t __table_upper_bound = 0x0003fffd;
   if (__code_point < (__entries[0] >> 14))
     return 1;
 
-  ptr
diff _t __i = std::ranges::upper_bound(__entries, (__code_point << 14) | 0x3fffu) - __entries;
+  ptr
diff _t __i =
+      std::upper_bound(std::begin(__entries), std::end(__entries), (__code_point << 14) | 0x3fffu) - __entries;
   if (__i == 0)
     return 1;
 

diff  --git a/libcxx/utils/generate_extended_grapheme_cluster_table.py b/libcxx/utils/generate_extended_grapheme_cluster_table.py
index eba88a4f48776..c64a5a00c4c16 100755
--- a/libcxx/utils/generate_extended_grapheme_cluster_table.py
+++ b/libcxx/utils/generate_extended_grapheme_cluster_table.py
@@ -135,7 +135,8 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
   // size. Then the upper bound for code point 3 will return the entry after
   // 0x1810. After moving to the previous entry the algorithm arrives at the
   // correct entry.
-  ptr
diff _t __i = std::ranges::upper_bound(__entries, (__code_point << 11) | 0x7ffu) - __entries;
+  ptr
diff _t __i =
+      std::upper_bound(std::begin(__entries), std::end(__entries), (__code_point << 11) | 0x7ffu) - __entries;
   if (__i == 0)
     return __property::__none;
 
@@ -212,7 +213,7 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
 #ifndef _LIBCPP___FORMAT_EXTENDED_GRAPHEME_CLUSTER_TABLE_H
 #define _LIBCPP___FORMAT_EXTENDED_GRAPHEME_CLUSTER_TABLE_H
 
-#include <__algorithm/ranges_upper_bound.h>
+#include <__algorithm/upper_bound.h>
 #include <__config>
 #include <__cstddef/ptr
diff _t.h>
 #include <__iterator/access.h>

diff  --git a/libcxx/utils/generate_indic_conjunct_break_table.py b/libcxx/utils/generate_indic_conjunct_break_table.py
index 580d8157ffebf..774a510849176 100755
--- a/libcxx/utils/generate_indic_conjunct_break_table.py
+++ b/libcxx/utils/generate_indic_conjunct_break_table.py
@@ -128,7 +128,8 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
   // size. Then the upper bound for code point 3 will return the entry after
   // 0x1810. After moving to the previous entry the algorithm arrives at the
   // correct entry.
-  ptr
diff _t __i = std::ranges::upper_bound(__entries, (__code_point << 11) | 0x7ffu) - __entries;
+  ptr
diff _t __i =
+      std::upper_bound(std::begin(__entries), std::end(__entries), (__code_point << 11) | 0x7ffu) - __entries;
   if (__i == 0)
     return __property::__none;
 
@@ -205,7 +206,7 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
 #ifndef _LIBCPP___FORMAT_INDIC_CONJUNCT_BREAK_TABLE_H
 #define _LIBCPP___FORMAT_INDIC_CONJUNCT_BREAK_TABLE_H
 
-#include <__algorithm/ranges_upper_bound.h>
+#include <__algorithm/upper_bound.h>
 #include <__config>
 #include <__cstddef/ptr
diff _t.h>
 #include <__iterator/access.h>

diff  --git a/libcxx/utils/generate_width_estimation_table.py b/libcxx/utils/generate_width_estimation_table.py
index f81f0ba77489e..618612c613741 100644
--- a/libcxx/utils/generate_width_estimation_table.py
+++ b/libcxx/utils/generate_width_estimation_table.py
@@ -170,7 +170,8 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
   if (__code_point < (__entries[0] >> 14))
     return 1;
 
-  ptr
diff _t __i = std::ranges::upper_bound(__entries, (__code_point << 14) | 0x3fffu) - __entries;
+  ptr
diff _t __i =
+      std::upper_bound(std::begin(__entries), std::end(__entries), (__code_point << 14) | 0x3fffu) - __entries;
   if (__i == 0)
     return 1;
 
@@ -244,9 +245,10 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
 #ifndef _LIBCPP___FORMAT_WIDTH_ESTIMATION_TABLE_H
 #define _LIBCPP___FORMAT_WIDTH_ESTIMATION_TABLE_H
 
-#include <__algorithm/ranges_upper_bound.h>
+#include <__algorithm/upper_bound.h>
 #include <__config>
 #include <__cstddef/ptr
diff _t.h>
+#include <__iterator/access.h>
 #include <cstdint>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)