Author: Arthur Eubanks Date: 2021-10-21T09:25:53-07:00 New Revision: 19b07ec00062daffcb2fb132f4ac0f2484ff44fa
URL: https://github.com/llvm/llvm-project/commit/19b07ec00062daffcb2fb132f4ac0f2484ff44fa DIFF: https://github.com/llvm/llvm-project/commit/19b07ec00062daffcb2fb132f4ac0f2484ff44fa.diff LOG: Reland [clang] Pass -clear-ast-before-backend in Clang::ConstructJob() This clears the memory used for the Clang AST before we run LLVM passes. https://llvm-compile-time-tracker.com/compare.php?from=d0a5f61c4f6fccec87fd5207e3fcd9502dd59854&to=b7437fee79e04464dd968e1a29185495f3590481&stat=max-rss shows significant memory savings with no slowdown (in fact -O0 slightly speeds up). For more background, see https://lists.llvm.org/pipermail/cfe-dev/2021-September/068930.html. Turn this off for the interpreter since it does codegen multiple times. Relanding with fix for -print-stats: D111973 Relanding with fix for plugins: D112190 If you'd like to use this even with plugins, consider using the features introduced in D112096. This can be turned off with -Xclang -no-clear-ast-before-backend. Differential Revision: https://reviews.llvm.org/D111270 Added: Modified: clang/lib/Driver/ToolChains/Clang.cpp clang/lib/Interpreter/Interpreter.cpp Removed: ################################################################################ diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 8dabfff64f80a..d5b5e3bb0bb84 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -4675,6 +4675,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, // cleanup. if (!C.isForDiagnostics()) CmdArgs.push_back("-disable-free"); + CmdArgs.push_back("-clear-ast-before-backend"); #ifdef NDEBUG const bool IsAssertBuild = false; diff --git a/clang/lib/Interpreter/Interpreter.cpp b/clang/lib/Interpreter/Interpreter.cpp index 02b3025297b67..d14940d2e1321 100644 --- a/clang/lib/Interpreter/Interpreter.cpp +++ b/clang/lib/Interpreter/Interpreter.cpp @@ -113,6 +113,10 @@ CreateCI(const llvm::opt::ArgStringList &Argv) { Clang->getTarget().adjust(Clang->getDiagnostics(), Clang->getLangOpts()); + // Don't clear the AST before backend codegen since we do codegen multiple + // times, reusing the same AST. + Clang->getCodeGenOpts().ClearASTBeforeBackend = false; + return std::move(Clang); } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
