Am 08.07.20 um 09:01 schrieb Mark Millard: > The following is more informational than anything as far > as I'm concerned. But there may be implications that I'm > unaware of. (I sometimes experiment with toolchain use > to see what the current status is for such use.) > > I attempted to build a system for 32-bit powerpc using clang > and binutils, building head -r363000 ( from -r363000 ). (This > was a cross build, amd64 -> powerpc.) It got a new type of > failure, compared to my past experience:
Hi Mark, thank you for the report. I have tested with "make universe" (with default settings) that this version builds on all architectures, but Ed Maste has already disabled -flto for powerpc64, due to run time issues (floating point exception, IIRC). I know that you are actively working on PowerPC and I'd appreciate, if you could provide me with information on which parameters cause breakage and which work for you. The combination of CLANG with LTO and GNU binutils cannot work - CLANG and GCC use incompatible file formats to represent the intermediate object files. This version of bc uses advanced algorithms (compared to the one it replaced) for much reduced time complexity (a factor of more than 100 for large numbers has been observed). It uses layering for correctness, e.g. a set of "vector" management functions, that are built as a separate compile unit. Compiling with -flto lets the linker replace many function calls with constant parameters with much more efficient inline instructions, resulting in 30% higher performance. The code could be re-arranged to use inline functions instead of relying on -flto, but this would be a lot of effort and might make the code much harder to maintain. If there is a condition that could be added to the Makefile to not enable LTO if CLANG+binutils or GCC+LLD are mixed, then I'm willing to add it. If more programs were to be built with LTO for performance reasons, then it might be a good idea to have a global parameter that controls whether lTO may be used, though. TL;DR Perhaps we could add a WITH(OUT)_LTO option that only affects specific programs that get a significant performance boost from building with LTO. IMHO, using LTO is preferable to the introduction of inline functions in source files that fall into that category. WITHOUT_LTO could be implied on platforms that are known to not fully support -flto with default their compiler and linker. And it could be set by the user when non-default build tools are used. This would allow to use -flto for specific programs without the need to make this optimization conditional on compilers or architectures. Best regards, STefan > --- gh-bc.full --- > /usr/local/powerpc-unknown-freebsd13.0/bin/ld: /usr/bin/../lib/LLVMgold.so: > error loading plugin: Cannot open "/usr/bin/../lib/LLVMgold.so" > cc: error: linker command failed with exit code 1 (use -v to see invocation) > *** [gh-bc.full] Error code 1 > > Yep: /usr/lib/LLVMgold.so when -B/usr/local/powerpc-unknown-freebsd13.0/bin/ > was in use. > > I turns out that the link of gh-bc used -flto : > > make[4]: stopped in /usr/src/usr.bin/gh-bc > .ERROR_TARGET='gh-bc.full' > .ERROR_META_FILE='/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/usr.bin/gh-bc/gh-bc.full.meta' > .MAKE.LEVEL='4' > MAKEFILE='' > .MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose' > _ERROR_CMD='cc -target powerpc-unknown-freebsd13.0 > --sysroot=/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp > -B/usr/local/powerpc-unknown-freebsd13.0/bin/ -O2 -pipe -fno-common > -B/usr/local/powerpc-unknown-freebsd13.0/bin/ -DMAINEXEC=bc > -DNLSPATH=/usr/share/nls/%L/%N.cat -DBC_ENABLED -DBC_ENABLE_PROMPT > -DBC_ENABLE_LONG_OPTIONS -DBC_ENABLE_EXTRA_MATH -DBC_ENABLE_HISTORY > -DBC_ENABLE_RAND -DDC_ENABLED -DNDEBUG -DVERSION=3.1.1 > -I/usr/src/contrib/bc/include -DBC_ENABLE_NLS=1 -flto -g -std=gnu99 > -Wno-format-zero-length -fstack-protector-strong -Wsystem-headers -Wall > -Wno-format-y2k -W -Wno-unused-parameter -Wstrict-prototypes > -Wmissing-prototypes -Wpointer-arith -Wreturn-type -Wcast-qual > -Wwrite-strings -Wswitch -Wshadow -Wunused-parameter -Wcast-align > -Wchar-subscripts -Winline -Wnested-externs -Wredundant-decls > -Wold-style-definition -Wno-pointer-sign -Wmissing-variable-declarations > -Wthread-safety -Wno-empty-body -Wno-string-plus-int -Wno-unused-cons t-variable -Qunused-arguments -Wl,--secure-plt -o gh-bc.full args.o data.o file.o lang.o lex.o main.o num.o parse.o program.o read.o vector.o vm.o bc/bc.o bc/lex.o bc/parse.o dc/dc.o dc/lex.o dc/parse.o history/history.o bc_help.o dc_help.o lib.o lib2.o opt.o rand/rand.o ;' > .CURDIR='/usr/src/usr.bin/gh-bc' > .MAKE='make' > .OBJDIR='/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/usr.bin/gh-bc' > .TARGETS='all' > DESTDIR='/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp' > LD_LIBRARY_PATH='' > MACHINE='powerpc' > MACHINE_ARCH='powerpc' > MAKEOBJDIRPREFIX='' > MAKESYSPATH='/usr/src/share/mk' > MAKE_VERSION='20200606' > PATH='/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp/usr/sbin:/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp/usr/bin:/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp/legacy/usr/sbin:/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp/legacy/usr/bin:/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp/legacy/bin:/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/tmp/legacy/usr/libexec::/sbin:/bin:/usr/sbin:/usr/bin' > SRCTOP='/usr/src' > OBJTOP='/usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc' > .MAKE.MAKEFILES='/usr/src/share/mk/sys.mk /usr/src/share/mk/local.sys.env.mk > /usr/src/share/mk/src.sys.env.mk > /root/src.configs/src.conf.powerpc-clang_altbinutils-bootstrap.amd64-host > /usr/src/share/mk/bsd.mkopt.mk /usr/src/share/mk/src.sys.obj.mk > /usr/src/share/mk/auto.obj.mk /usr/src/share/mk/bsd.suffixes.mk > /root/src.configs/make.conf /usr/src/share/mk/local.sys.mk > /usr/src/share/mk/src.sys.mk /dev/null /usr/src/usr.bin/gh-bc/Makefile > /usr/src/share/mk/src.opts.mk /usr/src/share/mk/bsd.own.mk > /usr/src/share/mk/bsd.opts.mk /usr/src/share/mk/bsd.cpu.mk > /usr/src/share/mk/bsd.compiler.mk /usr/src/share/mk/bsd.linker.mk > /usr/src/share/mk/bsd.prog.mk /usr/src/share/mk/bsd.init.mk > /usr/src/share/mk/local.init.mk /usr/src/share/mk/src.init.mk > /usr/src/usr.bin/gh-bc/../Makefile.inc /usr/src/share/mk/bsd.libnames.mk > /usr/src/share/mk/src.libnames.mk /usr/src/share/mk/bsd.nls.mk > /usr/src/share/mk/bsd.confs.mk /usr/src/share/mk/bsd.files.mk > /usr/src/share/mk/bsd.dirs.mk /usr/src/share/mk/bs d.incs.mk /usr/src/share/mk/bsd.links.mk /usr/src/share/mk/bsd.man.mk /usr/src/share/mk/bsd.dep.mk /usr/src/share/mk/bsd.clang-analyze.mk /usr/src/share/mk/bsd.obj.mk /usr/src/share/mk/bsd.subdir.mk /usr/src/share/mk/bsd.sys.mk' > .PATH='. /usr/src/usr.bin/gh-bc /usr/src/contrib/bc/src > /usr/src/contrib/bc/gen /usr/src/contrib/bc/manuals > /usr/obj/powerpcvtsc_clang_altbinutils/powerpc.powerpc/usr/src/powerpc.powerpc/usr.bin/gh-bc' > 1 error > > === > Mark Millard > marklmi at yahoo.com > ( dsl-only.net went > away in early 2018-Mar) > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
