From bdc3d0034d5b637b211abd01a936267df27118cc Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 20 Feb 2009 01:10:07 +0000 Subject: [PATCH] make the redeclaration case faster for the common instance of a redeclaration where there is exactly one existing declaration. This is common. this speeds up clang about 3% on cocoa.h for me 0.165 -> 0.160s git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65096 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/AST/DeclBase.cpp | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp index 9b277fe99c..a35dcc28bb 100644 --- a/lib/AST/DeclBase.cpp +++ b/lib/AST/DeclBase.cpp @@ -566,15 +566,26 @@ void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D) { return; } + // If it is possible that this is a redeclaration, check to see if there is + // already a decl for which declarationReplaces returns true. If there is + // one, just replace it and return. if (MayBeRedeclaration) { - // Determine if this declaration is actually a redeclaration. - std::vector::iterator Redecl - = std::find_if(DeclNameEntries.begin(), DeclNameEntries.end(), - std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), - D)); - if (Redecl != DeclNameEntries.end()) { - *Redecl = D; - return; + // Most decls only have one entry in their list, special case it. + if (DeclNameEntries.size() == 1) { + if (D->declarationReplaces(DeclNameEntries[0])) { + DeclNameEntries[0] = D; + return; + } + } else { + // Determine if this declaration is actually a redeclaration. + std::vector::iterator Redecl + = std::find_if(DeclNameEntries.begin(), DeclNameEntries.end(), + std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces), + D)); + if (Redecl != DeclNameEntries.end()) { + *Redecl = D; + return; + } } } -- 2.40.0