Hi, looks like XOP/FAM4/FAM is responsible for the additional errors I see when running gcc-testsuite or glibc-testsuite. I've opened Bug 56866 as a starting point, so the subject is a little bit misleading:
Bug 56866 - gcc 4.7.x/gcc-4.8.x with '-O3 -march=bdver2' misscompiles glibc-2.17/crypt/sha512.c Disabling XOP/FAM4/FAM shows no regression (compared with amdfam10) with glibc-testsuite and no additional execution-errors in the gcc-testsuite. Currently I'm running gcc-4.8-branch configured ith '--with-arch=bdver2' and with a simple patch disabling XOP/FAM4/FAM for bdver2 in gcc/config/i386/i386.c. regards winfried On Mon, Apr 01, 2013 at 08:44:59PM +0200, winfried.mag...@t-online.de wrote: > Hi, > > replacing my AMD Phenom2 with a AMD Piledriver (Bulldozer Version2) > was reason enough for me to recompile gcc (and the whole linux-system) > with hard optimisation set to bdver2 (as I've done since my first > linux on an 68030). > But this time an increasing number of errors makes me a little bit nervous > and after some additional errors when running the glibc-2.17-testsuite > I've refused to use this optimisation as default on my system. > > The results might be interesting for the gcc-developer-community and I've > mailed four results with different set of '--with-arch' and '--with-tune' > to gcc-testresu...@gcc.gnu.org from stock gcc-4.8.0. > I've set '--build=x86_64-winnix-linux-gnu' just to make it easier to search > the archive for this specific results (results include the complete set > of relevant libs/tools). > > Basic flags for every compile/test-run: > > --build=x86_64-winnix-linux-gnu --enable-languages=c,c++ --enable-shared > --prefix=/usr --enable-multilib=no > > optimization for phenom2 (I've used since I've replaced > my Athlon-FX): > --with-arch=amdfam10 --with-tune=amdfam10 > > soft-optimization for bdver2 which is the current configuration > I use on my system (no additional errors in glibc-2.17: > --with-arch=amdfam10 --with-tune=bdver2 > > optimization for bdver2: > --with-arch=bdver2 --with-tune=bdver2 > > The number of additional errors is always increasing. Mostly errors > in scan-assembler and scan-tree-dump (maybe wrong expections in the > tests?) but with arch=bdver2 I see an increasing number of > execution-tests failing. > > Surprisingly (at least for me) the difference is only visible in the > gcc-testsuite and doesn't harm other languages. > > I've done some work to ensure errors are not related to the system-setup > and maybe it's of interest what I've learned during this process: > > gcc.dg/guality/vla-1.c and vla-2.c depends on the gdb-version. Fails > with stock gdb-7.5.1 (also tested prerelease gdb-7.5.91) and don't > fail with gdb-patches from opensuse (fedora-patches works also). > Using tcl8.6.0 as base for expect/dejagnu doesn't currently work, > at least not with the gcc-testsuite. > > Please note that this is not a regression and that gcc-4.7.x gives > very similar results. > > Thank you for listening and all the good work I apreciate since > 20 years with all sorts of cpu's and operating-systems gcc > supports! > > best regards > > winfried >