http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51753
--- Comment #4 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> 2012-02-07 18:09:45 UTC --- > Please look at gcc.log files in your testsuite directory. There are extensive > single-instruction traces to analyse what went wrong. Comparing your traces to > linux execution should give you a hint. The Solaris results were completely nonsensical at first, but ultimately could be explained by a (long-standing, I suppose) and stupid gdb bug: http://sourceware.org/ml/gdb-patches/2012-02/msg00075.html With this fixed, all but the FAIL: gcc.dg/simulate-thread/atomic-load-int128.c -O0 -g thread simulation test failures (at all optimization levels) were gone. I didn't have the Linux/x86_64 gcc.log available for comparison, so I still have to investigate that one. On Solaris 10/x86, I'm sometimes still seeing FAILs, but they may just be timeouts. I've have to check that, too. I'm still seeing a large number of failures both on IRIX 6.5 and Tru64 UNIX V5.1B (both with gdb 7.4), but I suppose those are better filed as separate PRs. I certainly cannot compare gcc.log/g++.log output from other OSes since have no machines running e.g. Linux for comparison. Rainer