https://github.com/hardikxk created https://github.com/llvm/llvm-project/pull/206356
Resolves a FIXME and improved linear search by replacing with a binary search on the FileCheckPoints SmallVector in Lex/Preprocessor. - used std::upper_bound to find the upper bound of the Start position. - handle special case if the Start is less than all elements in FileCheckPoints so returns a nullptr; - else return the dereferenced value of the CheckPoint just before Start point. >From 25f04854d70116e6cecce9104daa89f8f58189bc Mon Sep 17 00:00:00 2001 From: hardikxk <[email protected]> Date: Sun, 28 Jun 2026 23:47:12 +0530 Subject: [PATCH] [clang][Lex] Optimize the FileCheckPoints search in Preprocessor Resolves a FIXME and improved linear search by replacing with a binary search on the FileCheckPoints SmallVector in Lex/PreProcessor. - used std::upper_bound to find the upper bound of the Start position. - handle special case if the Start is less than all elements in FileCheckPoints so returns a nullptr; - else return the dereferenced value of the CheckPoint just before Start point. --- clang/lib/Lex/Preprocessor.cpp | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp index c69d084d6514f..3f83546ea7956 100644 --- a/clang/lib/Lex/Preprocessor.cpp +++ b/clang/lib/Lex/Preprocessor.cpp @@ -1746,16 +1746,13 @@ void Preprocessor::removePPCallbacks() { const char *Preprocessor::getCheckPoint(FileID FID, const char *Start) const { if (auto It = CheckPoints.find(FID); It != CheckPoints.end()) { const SmallVector<const char *> &FileCheckPoints = It->second; - const char *Last = nullptr; - // FIXME: Do better than a linear search. - for (const char *P : FileCheckPoints) { - if (P > Start) - break; - Last = P; + auto P = + std::upper_bound(FileCheckPoints.begin(), FileCheckPoints.end(), Start); + if (P == FileCheckPoints.begin()) { + return nullptr; } - return Last; + return *std::prev(P); } - return nullptr; } _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
