On s390x, there are some libstdc++ failures that are not present on other platforms.
Here is a representative test run: http://gcc.gnu.org/ml/gcc-testresults/2009-01/msg02102.html And here is the failure analysis: http://gcc.gnu.org/ml/libstdc++/2009-01/msg00109.html The following fails appear to be spurious and only occur on s390x. At first I thought this might be because of the extra flags "-fstack-protector --param=ssp-buffer-size=4" but compiling the problem testcases on x86_64/linux with the same flag doesn't show an error. So, I don't know what's up. The same testcases (when present) pass without error on 4.3.2. FAIL: 21_strings/basic_string/element_access/wchar_t/empty.cc FAIL: 23_containers/list/modifiers/1.cc FAIL: 23_containers/list/modifiers/3.cc FAIL: 23_containers/list/modifiers/insert/25288.cc The usual error looks like: warning: dereferencing pointer '<anonymous>' does break strict-aliasing rules which is incomprehensible. -- Summary: [4.4 regression] dereferencing pointer '<anonymous>' does break strict-aliasing Product: gcc Version: unknown Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 Component: middle-end AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bkoz at gcc dot gnu dot org GCC host triplet: s390x-redhat-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38937