[Bug c/53083] gcc bug in moving from the SSE registers back onto the heap.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53083 --- Comment #7 from Da Fox 2012-05-01 07:54:54 UTC --- (In reply to comment #6) ... > The latest available gcc-version for my distribution (gentoo) appears to be > 4.6.2, which I will try next. This seems to still happen with 4.6.2 at least.
[Bug c/53083] New: gcc bug in moving from the SSE registers back onto the heap.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53083 Bug #: 53083 Summary: gcc bug in moving from the SSE registers back onto the heap. Classification: Unclassified Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassig...@gcc.gnu.org ReportedBy: da_...@mad.scientist.com After investigation of a suspected graphics-driver bug, it was found that the issue lay with gcc. Please see https://bugs.freedesktop.org/show_bug.cgi?id=47559 . The problem as I understand is that gcc-4.6.0 miscompiles miarc.c from the xorg-server package if -ftree-vectorize is enabled. This flag is enabled with -O3. The following minimal set of CFLAGS worked: "-g -O2" Adding the -ftree-vectorize separately, "-g -O2 -ftree-vectorize", caused the program to misbehave at runtime. I am running gentoo, the default CFLAGS for my system are: CFLAGS="-march=native -O3 -pipe -fomit-frame-pointer -fweb -ffast-math -mtune=native -mfpmath=sse" I don't know if these match exactly with what is passed by portage for compiling GCC. Software versions (gentoo package versions): sys-devel/gcc-4.6.0 x11-base/xorg-server-1.11.2-r2 My hardware is a Dell XPS 15 (L502x) laptop with a 'Intel(R) Core(TM) i7-2630QM CPU @ 2.00GHz' I additional information is required please let me know.
[Bug c/53083] gcc bug in moving from the SSE registers back onto the heap.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53083 --- Comment #2 from Da Fox 2012-04-23 12:26:53 UTC --- Created attachment 27220 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27220 .i version of miarc.c I think this is the information that was missing: The file in question compiled with CFLAGS="-O3 -pipe -fomit-frame-pointer -fweb -ffast-math -mtune=native -mfpmath=sse" (attached) gcc build options: >>> Compiling source in /var/tmp/portage/sys-devel/gcc-4.6.0/work/gcc-4.6.0 ... * CFLAGS="-march=native -pipe -mtune=native -O2" * CXXFLAGS="-march=native -pipe -mtune=native -O2" * Configuring gcc ... * configuring for GCC_LANG: c,c++,fortran * PREFIX:/usr * BINPATH:/usr/x86_64-pc-linux-gnu/gcc-bin/4.6.0 * LIBPATH:/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0 * DATAPATH:/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0 * STDCXX_INCDIR:/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0/include/g++-v4 * Configuring GCC with: * --prefix=/usr * --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.6.0 * --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0/include * --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0 * --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0/man * --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0/info * --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0/include/g++-v4 * --host=x86_64-pc-linux-gnu * --build=x86_64-pc-linux-gnu * --disable-altivec * --disable-fixed-point * --with-ppl * --with-cloog * --disable-ppl-version-check * --with-cloog-include=/usr/include/cloog-ppl * --enable-lto * --enable-nls * --without-included-gettext * --with-system-zlib * --disable-werror * --enable-secureplt * --disable-multilib * --disable-libmudflap * --disable-libssp * --enable-libgomp * --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.6.0/python * --enable-checking=release * --disable-libgcj * --enable-languages=c,c++,fortran * --enable-shared * --enable-threads=posix * --enable-__cxa_atexit * --enable-clocale=gnu * --enable-targets=all * --with-bugurl=http://bugs.gentoo.org/ * --with-pkgversion=Gentoo 4.6.0 p1.2, pie-0.4.5 Compiler does not seem to output anything relevant (no errors, compilation is successful).
[Bug c/53083] gcc bug in moving from the SSE registers back onto the heap.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53083 --- Comment #3 from Da Fox 2012-04-23 12:28:06 UTC --- gcc -v output: Using built-in specs. COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/4.6.0/gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.6.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-4.6.0/work/gcc-4.6.0/configure --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.6.0 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.6.0/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0/include/g++-v4 --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --disable-altivec --disable-fixed-point --with-ppl --with-cloog --disable-ppl-version-check --with-cloog-include=/usr/include/cloog-ppl --enable-lto --enable-nls --without-included-gettext --with-system-zlib --disable-werror --enable-secureplt --disable-multilib --disable-libmudflap --disable-libssp --enable-libgomp --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.6.0/python --enable-checking=release --disable-libgcj --enable-languages=c,c++,fortran --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-targets=all --with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.6.0 p1.2, pie-0.4.5' Thread model: posix gcc version 4.6.0 (Gentoo 4.6.0 p1.2, pie-0.4.5)
[Bug c/53083] gcc bug in moving from the SSE registers back onto the heap.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53083 Da Fox changed: What|Removed |Added Component|target |c --- Comment #6 from Da Fox 2012-04-25 07:30:27 UTC --- (In reply to comment #5) > BTW: Can you test if this problem is still present in a newer version of the > compiler (i.e. 4.6.3 or 4.7.0)? I've tried to take the source-file in question (miarc.c) and make something self-contained, but I was unable to make it work due to this being an internal xorg-file, apparently using and depending on internal headers. If you have any pointers on how to tackle such a situation to convert it to something selfcontained I'd be happy to try it out. The latest available gcc-version for my distribution (gentoo) appears to be 4.6.2, which I will try next.
