yurai007 added a comment. Disclaimer: I'm not front-end guy.
After running 7zip benchmark under perf and comparing origin (7acc88be031 <https://reviews.llvm.org/rG7acc88be0312c721bc082ed9934e381d297f4707>) with fix (0d300da799b0 <https://reviews.llvm.org/rG0d300da799b06931eb6b974198d683548a8c8392>) following diff can be seen: Instructions change | Symbol +0.12% | clang::Preprocessor::getMacroDefinition +0.07% | GetDeclSpecTypeForDeclarator +0.04% | clang::Parser::ParseDirectDeclarator +0.03% | clang::Sema::ActOnFunctionDeclarator +0.03% | clang::Sema::ProcessDeclAttributes In 8c7b64b5ae2a <https://reviews.llvm.org/rG8c7b64b5ae2a09027c38db969a04fc9ddd0cd6bb> commit those 2 code changes catch my eyes as (maybe) relevant to above perf diff: 1. Change in Parser::ParseDeclGroup. That function looks quite heavy and it's caller of ParseDirectDeclarator/ActOnFunctionDeclarator (and even getMacroDefinition?) 2. Change in GetDeclSpecTypeForDeclarator. After 8c7b64b5ae2a <https://reviews.llvm.org/rG8c7b64b5ae2a09027c38db969a04fc9ddd0cd6bb> distributeTypeAttrsFromDeclarator is called unconditionally which maybe matters. Hope it helps a bit in finding proper solution for slowdown. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D128097/new/ https://reviews.llvm.org/D128097 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
