Am 28.09.2014 um 10:44 schrieb Jorge Almeida: > I'm having a somewhat disgusting issue on my Gentoo: binaries are > unaccountably large. > > I'm talking about C programs of my own, so no version related issues > whatsoever. The computer is a core i3 with a 32 bit system. > > Example, for the same program: > > 10275 B on an atom running Slackware 14.1 (gcc 4.8.2) > 5896 B (same, stripped with strip --strip-unneeded) > > 11675 B on i3, Gentoo, gcc 4.8.3 (with default gcc it was worse) > 9704 B stripped > > 8207 B on *the same i3 box* running LFS (gcc 4.9.1) > 5768 B stripped > > When compiling against dietlibc, the difference is even more shocking > (almost double size in Gentoo after stripping). > > Compiled with: > gcc -Os -march=i686 -fomit-frame-pointer -pipe -Wall -pedantic > -fdata-sections -ffunction-sections -Wl,--gc-sections > -fno-asynchronous-unwind-tables -std=c99 > > Gentoo: > $ gcc -v > Using built-in specs. > COLLECT_GCC=/usr/i686-pc-linux-gnu/gcc-bin/4.8.3/gcc > COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i686-pc-linux-gnu/4.8.3/lto-wrapper > Target: i686-pc-linux-gnu > Configured with: > /var/tmp/portage/sys-devel/gcc-4.8.3/work/gcc-4.8.3/configure > --host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --prefix=/usr > --bindir=/usr/i686-pc-linux-gnu/gcc-bin/4.8.3 > --includedir=/usr/lib/gcc/i686-pc-linux-gnu/4.8.3/include > --datadir=/usr/share/gcc-data/i686-pc-linux-gnu/4.8.3 > --mandir=/usr/share/gcc-data/i686-pc-linux-gnu/4.8.3/man > --infodir=/usr/share/gcc-data/i686-pc-linux-gnu/4.8.3/info > --with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/4.8.3/include/g++-v4 > --with-python-dir=/share/gcc-data/i686-pc-linux-gnu/4.8.3/python > --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt > --disable-werror --with-system-zlib --disable-nls > --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ > --with-pkgversion='Gentoo 4.8.3' --enable-libstdcxx-time > --enable-shared --enable-threads=posix --enable-__cxa_atexit > --enable-clocale=gnu --disable-multilib --disable-altivec > --disable-fixed-point --with-arch=i686 --enable-targets=all > --disable-libgcj --enable-libgomp --disable-libmudflap > --disable-libssp --enable-lto --without-cloog > Thread model: posix > gcc version 4.8.3 (Gentoo 4.8.3) > > LFS: > ## gcc -v > Using built-in specs. > COLLECT_GCC=gcc > COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i686-pc-linux-gnu/4.9.1/lto-wrapper > Target: i686-pc-linux-gnu > Configured with: ../gcc-4.9.1/configure --prefix=/usr > --enable-languages=c,c++ --disable-multilib --disable-bootstrap > --with-system-zlib > Thread model: posix > gcc version 4.9.1 (GCC) > > Slackware: > Reading specs from /slash/usr/bin/../lib/gcc/i486-slackware-linux/4.8.2/specs > COLLECT_GCC=gcc > COLLECT_LTO_WRAPPER=/slash/usr/bin/../libexec/gcc/i486-slackware-linux/4.8.2/lto-wrapper > Target: i486-slackware-linux > Configured with: ../gcc-4.8.2/configure --prefix=/usr > --libdir=/usr/lib --mandir=/usr/man --infodir=/usr/info > --enable-shared --enable-bootstrap > --enable-languages=ada,c,c++,fortran,go,java,lto,objc > --enable-threads=posix --enable-checking=release --enable-objc-gc > --with-system-zlib --with-python-dir=/lib/python2.7/site-packages > --disable-libunwind-exceptions --enable-__cxa_atexit --enable-libssp > --enable-lto --with-gnu-ld --verbose --enable-java-home > --with-java-home=/usr/lib/jvm/jre --with-jvm-root-dir=/usr/lib/jvm > --with-jvm-jar-dir=/usr/lib/jvm/jvm-exports --with-arch-directory=i386 > --with-antlr-jar=/root/slackware-current/source/d/gcc/antlr-runtime-3.4.jar > --enable-java-awt=gtk --disable-gtktest --with-arch=i486 > --target=i486-slackware-linux --build=i486-slackware-linux > --host=i486-slackware-linux > Thread model: posix > gcc version 4.8.2 (GCC) > > I'm not elfwise, but I could post something to google drive if needed. > > TIA > > Jorge Almeida > Hi :)
I have compared some exes and libs from Ubuntu 14.04 and my Gentoo (both x86_64) and for similar versions it seems like most of _my_ Gentoo binaries are around 10% bigger (a few are 10% smaller). I have completely ignored GCC settings (both are 4.8.x though). IMO your sample (one 5-10 kb program) is not representative for the distro in general. I compared: /bin/bash /usr/bin/xterm /bin/bzip2 /bin/gzip /usr/bin/xz /usr/bin/xev /usr/lib/libaspell.so /usr/lib/libdaemon.so IMO you shouldn't compare 4.8.x with 4.9.x. I don't want to dismiss your concern with your specific program. In your case it is a big difference, and I'm curios too, where it comes from. Maybe you can find out more by a more thorough comparation of the flags GCC uses at runtime by comparing the output of: gcc -Q <your flags (w/o -pipe)> --help=target gcc -Q <your flags (w/o -pipe)> --help=optimizers (Find more --help=____ in the man page.) Greetings Daniel -- Get my PGP key at: * http://keyserver.ubuntu.com:11371/pks/lookup?op=get&search=0x837FB8B5BB9D4887 * $ gpg --recv-keys --keyserver keyserver.ubuntu.com 0xBB9D4887
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