I have identified that http://gcc.gnu.org/ml/gcc-patches/2005-12/msg01261.html
causes FORTRAN program to generate wrong result on ia64 -- Summary: [4.1/4.2 Regression]: Miscompiled FORTRAN program Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: hjl at lucon dot org GCC build triplet: ia64-unknown-linux-gnu GCC host triplet: ia64-unknown-linux-gnu GCC target triplet: ia64-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25603