From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp50.i.mail.ru (smtp50.i.mail.ru [94.100.177.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 6975D469710 for ; Mon, 25 May 2020 18:00:50 +0300 (MSK) References: <20200312100549.31608-1-arkholga@tarantool.org> <20200414091803.GJ5713@tarantool.org> <20200525125827.GA20107@pony.bronevichok.ru> From: Olga Arkhangelskaia Message-ID: Date: Mon, 25 May 2020 18:00:48 +0300 MIME-Version: 1.0 In-Reply-To: <20200525125827.GA20107@pony.bronevichok.ru> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Content-Language: en-GB Subject: Re: [Tarantool-patches] [PATCH] cmake: add LTO support for building luajit List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Sergey Bronnikov Cc: tarantool-patches@dev.tarantool.org Hello Sergey! Thanks for review and testing. However,  -DENABLE_LTO=ON is not set by default, yu have to set it. I followed your way:  cmake . -DCMAKE_LINKER=/usr/bin/ld.gold -DENABLE_LTO=ON -- ld version string: GNU ld version 2.30-58.el8_1.2 -- Found ld.bfd version: 2.30 CMake Error at cmake/lto.cmake:79 (message):   ld.bfd >= 2.31 is needed for LTO Call Stack (most recent call first):   CMakeLists.txt:68 (include) As far as I understand there gold/bfd is the frontend to binutils, so it is impossible om msc. I did the same at the debian docker container: Generating third_party/luajit/src/libluajit.a cd /tarantool/third_party/luajit && make BUILDMODE=static HOST_CC="/usr/bin/cc" TARGET_CC="/usr/bin/cc" TARGET_CFLAGS="-fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -fopenmp -msse2 -Wno-parentheses-equality -Wno-tautological-compare -Wno-misleading-indentation -Wno-varargs -Wno-implicit-fallthrough -flto -fuse-linker-plugin -fno-fat-lto-objects" TARGET_LD="/usr/bin/ld" TARGET_LDFLAGS=" -Wno-lto-type-mismatch" TARGET_AR="gcc-ar rcus" TARGET_STRIP="/usr/bin/strip" TARGET_SYS="Linux" CCOPT="-O2" CCDEBUG="" XCFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -DNDEBUG -DNVALGRIND -DNVALGRIND=1 -DLUAJIT_ENABLE_PAIRSMM=1 -DLUAJIT_SMART_STRINGS=1" Q='' MACOSX_DEPLOYMENT_TARGET="" clean So the -flto is passet to luajit. I will check formatting once again. 25.05.2020 15:58, Sergey Bronnikov пишет: > Olya, > > I have reviewed patch in a branch and below my comments. > > formatting issues still exist: > > + if (CMAKE_COMPILER_IS_CLANG) > + if (${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 3.9) > + set (luajit_cflags ${luajit_cflags} -flto=full) > + else() > + # ThinLTO that is both scalable and incremental > + # due to parallel IPO, available since 3.9 and above. > + # See http://blog.llvm.org/2016/06/thinlto-scalable-and-incremental-lto.html > + set (luajit_cflags ${luajit_cflags} -flto=thin) > + endif() > + # XCode linker dynamically load libLTO.dylib to perform > + # link-time optimization. > + # http://lists.llvm.org/pipermail/llvm-dev/2009-November/027103.html > ^^^^^^^^^^^^^^^^^^^^^^^^ > > + if (NOT TARGET_OS_DARWIN) > + # llvm-ar is just a wrapper over ar to pass --plugin= option, > + # so that ar can understand LTO objects. > + # See https://lists.llvm.org/pipermail/llvm-dev/2018-March/122018.html > + set (CMAKE_AR llvm-ar) > + endif() > + else() > + # GNU opts to support lto > ^^^^^^^^^^^^^^^^^^^^^^ > > + # Due to some problems (bugs, slow work, etc) we support LTO > + # only for 5.0+. The same is for binutils prior to 2.27 > + # See comments in scripts/Makefile.lto in scope of > > > + # the patch: https://patchwork.kernel.org/patch/10078207/ > + if (NOT ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 5.0 > + AND NOT ${linker_version} VERSION_LESS 2.27) > + set (luajit_cflags ${luajit_cflags} -flto -fuse-linker-plugin -fno-fat-lto-objects) > + endif() > ^^^^^^^^^^^^^^^^^^^^^^ > + # gcc-ar is just a wrapper over ar to pass --plugin option > > Unfortunatlely I have no minimal required version of binutils on my system > and I tested patch with ld gold (cmake -DCMAKE_LINKER=/usr/bin/ld.gold ..), > as Timur Safin advised. > > How I tested: > $ mkdir build; cd build > $ make build_bundled_libs VERBOSE=1 2>&1 | tee log.txt > > with commands above output in log.txt doesn't contain LTO related options > in compilation lines for luajit. > > gcc 8.3.1, clang 8.0.1, CentOS 8.1.1911 > > Sergey > > On 17:33 Tue 14 Apr , Olga Arkhangelskaia wrote: >> Fixed tabs: >> >>  +            # Depending of compiler we need to set appropriate llvm/gcc-ar >> lib >>  +            # llvm/gcc -ar is just a wrapper over ar to pass --plugin= >> option, >>  +            # so that ar can understand LTO objects. >> >> 14.04.2020 12:18, Igor Munkin пишет: >>> Olya, >>> >>> Thanks for the patch! I left several comments below, please consider >>> them. >>> >>> On 12.03.20, Olga Arkhangelskaia wrote: >>>> Tarantool has LTO support, however while building luajit this opt. was >>>> omitted. Patch adds necessary flag to turn it on. >>>> >>>> Minimum compiler/linker versions: clang 3.4, gcc 5.0+, ld 2.27+. >>>> >>>> Closes #3743 >>>> --- >>>> Branch: OKriw/gh-3743-LuaJIT-does-not-use-LTO-with-DENABLE_LTO=ON-full-ci >>>> cmake/lto.cmake | 3 ++- >>>> cmake/luajit.cmake | 26 ++++++++++++++++++++++++++ >>>> 2 files changed, 28 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/cmake/lto.cmake b/cmake/lto.cmake >>>> index 95ade75f4..9f29f3324 100644 >>>> --- a/cmake/lto.cmake >>>> +++ b/cmake/lto.cmake >>>> @@ -78,7 +78,8 @@ if (NOT TARGET_OS_DARWIN) >>>> if (linker_version VERSION_LESS "2.31") >>>> message(FATAL_ERROR "ld.bfd >= 2.31 is needed for LTO") >>>> endif() >>>> - elseif(matched_gold) >>>> + >>>> + elseif(matched_gold) >>> Typo: there is a mess with whitespace above. >>> >>> However this chunk provides no changes except whitespace and newline. >>> Please drop it. >>> >>>> set(linker_version ${CMAKE_MATCH_1}) >>>> message(STATUS "Found ld.gold version: ${linker_version}") >>>> diff --git a/cmake/luajit.cmake b/cmake/luajit.cmake >>>> index 072db8269..da1b4926d 100644 >>>> --- a/cmake/luajit.cmake >>>> +++ b/cmake/luajit.cmake >>>> @@ -225,6 +225,32 @@ macro(luajit_build) >>>> set(luajit_xcflags ${luajit_xcflags} -D${def}) >>>> endforeach() >>>> + # Add LTO option to luajit >>>> + if (CMAKE_INTERPROCEDURAL_OPTIMIZATION) >>>> + message("Setting LTO flags for building luajit") >>>> + # Clang opt to support LTO >>>> + if (CMAKE_COMPILER_IS_CLANG AND >>>> + NOT ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 3.4) >>> So, if clang toolchain is used but version is less than 3.4, then gcc >>> toolchain settings are used. It's either totally wrong or definitely >>> need to be clarified with a corresponding comment. >>> >>> Also, AFAICS LTO support for toolchain is checked via CheckIPOSupported >>> CMake module. So additional check here looks to be excess or also need >>> to be clarified. >>> >>>> + if (${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 3.9) >>>> + set(luajit_cflags ${luajit_cflags} -flto=full) >>>> + else() >>>> + set(luajit_cflags ${luajit_cflags} -flto=full) >>>> + endif() >>> I see no difference in the branches above. >>> >>>> + if (NOT TARGET_OS_DARWIN) >>>> + # Depending of compiler we need to set appropriate llvm/gcc-ar lib >>>> + set (CMAKE_AR llvm-ar) >>> What ar is used on systems different from Darwin based ones when clang >>> toolchain is used? >>> >>>> + endif() >>>> + # GNU opts to support lto >>>> + else() >>>> + #Due to some problems (bugs, slow work, etc) we support LTO only for 5.0+ >>>> + #The same is for binutils prior 2.27 >>>> + if (NOT ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 5.0 >>>> + AND NOT ${linker_version} VERSION_LESS 2.27) >>>> + set(luajit_cflags ${luajit_cflags} -flto -fuse-linker-plugin -fno-fat-lto-objects) >>>> + endif() >>>> + set (CMAKE_AR gcc-ar) >>> Could you please clarify why ar is set explicitly here? >>> >>>> + endif() >>>> + endif() >>> Typo: there is a mess with indent above. Unfortunately I failed to find >>> our CMake style guide, so please adjust your changes considering the >>> code nearby. >>> >>>> # Pass the same toolchain that is used for building of >>>> # tarantool itself, because tools from different toolchains >>>> # can be incompatible. A compiler and a linker are already set >>>> -- >>>> 2.20.1 (Apple Git-117) >>>>