http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57192
--- Comment #12 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> 2013-05-08 13:03:59 UTC --- Reduced testcase that still triggers the valgrind warning during compilation: MODULE orbital_pointers INTEGER, DIMENSION(:,:), ALLOCATABLE :: soset CONTAINS SUBROUTINE create_orbital_pointers(maxl) soset(:,:) = 0 END SUBROUTINE create_orbital_pointers END MODULE orbital_pointers gfortran -O3 ==81795== Conditional jump or move depends on uninitialised value(s) ==81795== at 0xDF5DAB: register_active_defs(df_ref_d**) (sparseset.h:147) ==81795== by 0xDF5E52: update_df_init(rtx_def*, rtx_def*) [clone .isra.11] (fwprop.c:894) ==81795== by 0xDF65F1: try_fwprop_subst(df_ref_d*, rtx_def**, rtx_def*, rtx_def*, bool) (fwprop.c:962) ==81795== by 0xDF6A91: forward_propagate_into(df_ref_d*) (fwprop.c:1342) ==81795== by 0xDF7B27: fwprop() (fwprop.c:1479) ==81795== by 0x9021DF: execute_one_pass(opt_pass*) (passes.c:2337) ==81795== by 0x902644: execute_pass_list(opt_pass*) (passes.c:2389) ==81795== by 0x902656: execute_pass_list(opt_pass*) (passes.c:2390) ==81795== by 0x6CC857: expand_function(cgraph_node*) (cgraphunit.c:1640) ==81795== by 0x6CE5FC: compile() (cgraphunit.c:1744) ==81795== by 0x6CEC94: finalize_compilation_unit() (cgraphunit.c:2119) ==81795== by 0x8992FA: write_global_declarations() (langhooks.c:322)