# gcc -Wall -O2 -c demo.cxx demo.cxx: In function void isInvertible(): demo.cxx:12: warning: array subscript is above array bounds
gcc --version gcc (GCC) 4.4.2 20091019 (Red Hat 4.4.2-5) I've the same results with... gcc (GCC) 4.4.2 20091019 (Red Hat 4.4.2-5) (gcc-4.4.2-5.el6.s390x) gcc (GCC) 4.4.1 20090725 (Red Hat 4.4.1-3) (gcc-4.4.1-3.s390x) gcc (GCC) 4.4.0 20090506 (Red Hat 4.4.0-4) (gcc-4.4.0-4.s390x) Possibly a duplicate of #35392 so its not a very recent thing. I only get this warning (and related runtime failure) with s390x. Equivalent x86_64/x86/ppc/ppc64/arm gcc's appear fine -- Summary: warning: array subscript is above array bounds Product: gcc Version: 4.4.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: caolanm at redhat dot com GCC build triplet: s390x-ibm-linux GCC host triplet: s390x-ibm-linux GCC target triplet: s390x-ibm-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41847