From 669ddd1e9b1226432b003dbba05b99f8e992285b Mon Sep 17 00:00:00 2001 From: Arthur Eubanks Date: Mon, 25 Jan 2021 11:00:56 -0800 Subject: [PATCH] Turn on the new pass manager by default This turns on the new pass manager by default for the optimization pipeline in Clang and ThinLTO in various LLD backends. This also makes uses of `opt -instcombine` use the new pass manager (unless specifically opted out). This does not affect the backend target-dependent codegen pipeline. If this causes regressions, you can opt out of the new pass manager either via the -DENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=OFF CMake flag while building LLVM, or via various compiler flags, e.g. -flegacy-pass-manager for Clang or -Wl,--lto-legacy-pass-manager for ELF LLD. Please file bugs for any regressions. Major differences: * The inliner works slightly differently * -O1 does some amount of inlining * LCSSA and LoopSimplify are run before all loop passes * Loop unswitching is implemented slightly differently * A new SpeculateAroundPHIs pass is added to the pipeline https://lists.llvm.org/pipermail/llvm-dev/2021-January/148098.html Reviewed By: asbirlea, ychen, MaskRay, echristo Differential Revision: https://reviews.llvm.org/D95380 --- llvm/CMakeLists.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt index 1affc28..f5298de 100644 --- a/llvm/CMakeLists.txt +++ b/llvm/CMakeLists.txt @@ -688,8 +688,8 @@ else() endif() option(LLVM_ENABLE_PLUGINS "Enable plugin support" ${LLVM_ENABLE_PLUGINS_default}) -set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER FALSE CACHE BOOL - "Enable the experimental new pass manager by default.") +set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER TRUE CACHE BOOL + "Enable the new pass manager by default.") include(HandleLLVMOptions) -- 2.7.4