https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71087
--- Comment #9 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> --- (In reply to Nick from comment #0) > Created attachment 38475 [details] > Source code trigging bug > > - Compiling amos/zunhj.f in scipy package crashes with: > > zunhj.f:1:0: > > SUBROUTINE ZUNHJ(ZR, ZI, FNU, IPMTR, TOL, PHIR, PHII, ARGR, ARGI, > > internal compiler error: Illegal instruction > 0xa64def crash_signal > ../../gcc/toplev.c:333 > Please submit a full bug report, > with preprocessed source if appropriate. > Please include the complete backtrace with any bug report. > See <http://gcc.gnu.org/bugs.html> for instructions. > > > - This bug happens whenever -OX, for X>=1 is in effect. > Have you tried using -march=opteron There are subtle differences between plain vanilla x86 with different chips. If the gcc build was for Intel on Intel it may be defaulting the instruction set.