after further inspection it turns out it's a performance regression between llvm 5 and llvm 6:
$homebrew_D/Cellar/llvm/5.0.1/lldb -s test_lldb.txt -- prog 8 seconds $homebrew_D/Cellar/llvm/6.0.0/bin/lldb -s test_lldb.txt -- prog 40 seconds cat test_lldb.txt: ``` b FOO r bt q ``` prog is some binary I'm debugging. It's unfortunately hard to reduce. What are good ways to investigate this? On Mon, Mar 12, 2018 at 1:42 PM, Adrian Prantl <apra...@apple.com> wrote: > Have you tried diff'ing your cmake invocation against the on used by homebrew? > > -- adrian > >> On Mar 9, 2018, at 12:59 AM, Timothee Cour via lldb-dev >> <lldb-dev@lists.llvm.org> wrote: >> >> while testing out https://github.com/llvm-mirror/lldb/pull/3 I noticed >> that when I compiled lldb from source (even un-modified from git HEAD) >> it was 5X slower than homebrew lldb or default lldb: >> >> I'm compiling lldb as follows: >> ``` >> git clone https://github.com/llvm-mirror/llvm.git >> cd llvm/tools >> git clone https://github.com/llvm-mirror/lldb >> ## also, patch in https://github.com/llvm-mirror/lldb/pull/3 >> git clone https://github.com/llvm-mirror/clang >> cd .. >> mkdir build >> cd build >> ccmake .. -G Ninja >> # here I set: CMAKE_BUILD_TYPE Release >> ninja all >> ``` >> >> I also tried setting `LLVM_ENABLE_ASSERTIONS OFF` but no difference >> >> >> commands.txt >> ``` >> b FOO >> r >> bt >> q >> ``` >> >> ./test is some program i have. >> >> ``` >> time lldb -s commands.txt -- ./test >> 8 seconds >> time ./build/bin/lldb -s commands.txt -- ./test >> 40 seconds >> ``` >> _______________________________________________ >> lldb-dev mailing list >> lldb-dev@lists.llvm.org >> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev > _______________________________________________ lldb-dev mailing list lldb-dev@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
