On 04/07/2010 08:36 AM, Ralf Wildenhues wrote: > * Török Edwin wrote on Sun, Apr 04, 2010 at 06:03:35PM CEST: >> On 04/04/2010 11:54 AM, Ralf Wildenhues wrote: >>> I have a preliminary(!) patch set here for LTO support in libtool. > >> Thanks a lot for the patches, they worked fine so far! > > Thanks for testing. > >> I'd have one more request: please add "-use-gold-plugin" to the list of >> flags passed through to support LLVM's LTO described here: >> http://llvm.org/docs/GoldPlugin.html > > Yes. I'm not sure whether I mentioned it before, but I didn't manage to > build a working llvm/clang from its svn last weekend (I tried about > three revisions and all of them failed to build with syntax errors, so I > gave up for the moment).
If you tell me the error message, and how you configured LLVM I can probably fix it (I have commit access). Note that llvm-gcc should be built with objdir != srcdir, since it has an Apple-specific GNUmakefile in the root causes srcdir == objdir builds to fail, you should pass --enable-languages since not all languages that are supported by gcc are supported by LLVM. > Do they not have a checkin policy that code > needs to compile at least? There are some buildbots that test whether code compiles, and build/test failures are usually quickly fixed/reverted. All looks green (except some selfhosting and valgrind failures): http://google1.osuosl.org:8011/waterfall You can try the 2.7 prerelease branch (branches/release_27), or the tarballs here: http://llvm.org/pre-releases/2.7/pre-release1/ > Anyway, it's good that you did some testing > here. Can you please also test the Libtool package with this: > >> ./configure >> CC=/home/edwin/llvm2.7/llvm-gcc-4.2-2.7-x86_64-linux/bin/llvm-gcc >> CXX=/home/edwin/llvm2.7/llvm-gcc-4.2-2.7-x86_64-linux/bin/llvm-g++ >> CFLAGS="-O4 -use-gold-plugin" CXXFLAGS="-O4 -use-gold-plugin" > > and run its testsuites and report results (see README for how)? Thanks. After adding the -use-gold-plugin to libltdl/config/ltmain.m4sh I 1 failure: FAIL: tests/pdemo-make.test ==================================== 1 of 113 tests failed (11 tests were not run) 18: duplicate convenience archive names FAILED (duplicate_conv.at:79) 102: Run tests with low max_cmd_len FAILED (cmdline_wrap.at:43) ## ------------- ## ## Test results. ## ## ------------- ## ERROR: 99 tests were run, 6 failed (4 expected failures). 7 tests were skipped. I think these are the the same as gcc+gold (since LLVM uses gold for LTO too). The duplicate_conv failure is because apparently libtool doesn't pass -use-gold-plugin here (hence LD doesn't know that it needs to use the plugin to link, and the .o files are not ELF objects, as with gcc): ./duplicate_conv.at:79: $LIBTOOL --mode=link --tag=CC $CC $CFLAGS $LDFLAGS -o cee.$OBJEXT c.lo a/liba.la b/liba.la stderr: /usr/bin/ld: error: .libs/c.o:1:3: invalid character /usr/bin/ld: error: .libs/c.o:1:3: syntax error, unexpected $end /usr/bin/ld: error: .libs/c.o: not an object or archive /usr/bin/ld: error: a/.libs/liba.a: member at 78 is not an ELF object /usr/bin/ld: error: b/.libs/liba.a: member at 86 is not an ELF object /usr/bin/ld: error: b/.libs/liba.a: member at 626 is not an ELF object > >> ac_cv_c_fpu_bigendian=no > > How come you need to use that, and which Autoconf version do you use? > This sounds like it needs to be addressed in Autoconf. Thanks. No this is a test implement in ClamAV's acinclude.m4 (yes I know it uses the wrong macro namespace). Problem is it uses 'grep' to find out if the compiled code has big-endian or little-endian FPU word ordering. That works with gcc, but doesn't work with LLVM's bitcode files (since the actualy constant is VBR-encoded). > >> Everything worked fine, and make check passed too! >> (Now of course it didn't LTO the entire program because >> -fuse-linker-plugin triggers PR41584) > > AFAIK -fuse-linker-plugin does not trigger PR 41584, only -fwhopr does. > Did you mean one of the other ones? -fuse-linker-plugin hits #42453 which is similar to 41584 (same assertion), either the optimizer creates empty TU, or it drops some symbols and later tries to write out the non-existent symbol. Best regards, --Edwin
