David and all, a couple more questions. I stumbled upon http://llvm.org/docs/Packaging.html and see a few other options. For a typical clang build where I am not hacking on clang, but I do want good error messages for debugging my programs, which options are recommended [1]? It seems like I should use --disable-assertions, but I'm not sure about enable-debug-symbols and enable-optimized (which seem at odds with each other?). I'm basically just looking for the same options that would come with a packaged build, but I do want to build from source.
Finally, when I'm done, how do I verify that the settings are correct? clang --version doesn't tell me much about if I built it correctly. [2] Thank you, Jim [1] --disable-assertions--enable-debug-symbols--enable-optimized [2] $ clang --version clang version 3.9.0 (trunk 263648) Target: x86_64-apple-darwin15.0.0 Thread model: posix InstalledDir: /Users/jim/toolchains/llvm/bin On Wed, Mar 16, 2016 at 2:05 PM, jps...@gmail.com <jps...@gmail.com> wrote: > Got it -- thanks! > > > On Wednesday, March 16, 2016, David Blaikie <dblai...@gmail.com> wrote: > >> >> >> On Wed, Mar 16, 2016 at 7:25 AM, jps...@gmail.com via cfe-users < >> cfe-users@lists.llvm.org> wrote: >> >>> Hi, I recently installed "Release" clang (svn r263305) from source on my >>> OSX machine, and it's compiling a 20 file C++ program about 50% slower than >>> the natively installed clang 3.7 (that came with xcode, I believe, although >>> I don't use xcode). I currently have both sets of tools installed and am >>> able to switch back and forth and verify using time that clang 3.7 takes >>> about 30 seconds and clang 3.9 takes about 45 seconds, on average (all >>> flags, settings, etc. are the same for both). I did build with "Release" as >>> the build type, although I also did set DLLVM_ENABLE_ASSERTIONS=ON (could >>> this be the problem?). >>> >> >> Yes, the build system should print a warning telling you that an >> assertions enabled build can be up to ten times slower. Performance >> comparisons/measurements of an assertions enabled compiler aren't something >> we really do/tune for. >> >> >>> More details below. Please let me know if you have any ideas about why >>> this newer clang would be noticable slower. >>> >>> Generally, I'm just trying to use clang as a user, not a clang >>> developer, so if you have general recommendations for how to configure >>> this, please let me know. >>> >>> Thank you, >>> Jim >>> >>> How I configured and installed: >>> >>> cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release >>> -DLLVM_ENABLE_ASSERTIONS=ON ../llvm >>> make >>> cmake -DCMAKE_INSTALL_PREFIX=$CLANG_PREFIX -P cmake_install.cmake >>> >>> >>> Here are some specifics: >>> >>> $ uname -a >>> Darwin localhost 15.0.0 Darwin Kernel Version 15.0.0: Wed Aug 26 >>> 16:57:32 PDT 2015; root:xnu-3247.1.106~1/RELEASE_X86_64 x86_64 >>> >>> $ clang --version >>> clang version 3.9.0 (trunk 263305) >>> Target: x86_64-apple-darwin15.0.0 >>> Thread model: posix >>> InstalledDir: /Users/jim/toolchains/llvm/bin >>> >>> _______________________________________________ >>> cfe-users mailing list >>> cfe-users@lists.llvm.org >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users >>> >>> >>
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