http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51267
kargl at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |kargl at gcc dot gnu.org --- Comment #1 from kargl at gcc dot gnu.org 2011-11-22 15:40:43 UTC --- (In reply to comment #0) > Created attachment 25880 [details] > simple source file > > The small program attached fails using gfortran 4.6.1 (ubuntu oneiric built) > using -O1 optimization level or higher (ok at -O0). > It succeeds with gfortran 4.5.4 at all -O levels. > > It ends by printing a boolean value : T if the test is ok, F else. > > $ gfortran-4.5 -O1 -Wall -Wextra bug46_stat.f ; ./a.out > tab( 1 )= -1 > tab( 2 )= -1 > tab( 3 )= -1 > tab( 4 )= -1 > tab( 5 )= -1 > tab( 6 )= -1 > T > > $ gfortran-4.6 -O1 -Wall -Wextra bug46_stat.f ; ./a.out > tab( 1 )= 134520832 > tab( 2 )= 10813028 > tab( 3 )= -1 > tab( 4 )= 0 > tab( 5 )= 10870894 > tab( 6 )= -1 > F > > > Ouput with '-v' : Have you considered compiling the code with -fcheck=all? It shows that you have an array reference issue. troutmask:sgk[206] gfc4x -o z -fcheck=all -O bug46_stat.f troutmask:sgk[207] ./z At line 10 of file bug46_stat.f Fortran runtime error: Index '-7' of dimension 1 of array 'ius' below lower bound of 1