On the "test" data set, (not the "ref" data set) of 434.zeusmp there is a miscompare when using -fgraphite-identity. This failure appeared with my patch to handle reductions:
Rewrite reductions out of SSA. 2009-07-28 Sebastian Pop <sebastian....@amd.com> * graphite-sese-to-poly.c (loop_entry_phi_arg): New. (remove_simple_copy_phi): New. (remove_invariant_phi): New. (simple_copy_phi_p): New. (reduction_phi_p): New. (gsi_for_ssa_name_def): New. (insert_out_of_ssa_copy): New. (insert_out_of_ssa_copy_on_edge): New. (create_zero_dim_array): New. (scalar_close_phi_node_p): New. (rewrite_close_phi_out_of_ssa): New. (rewrite_phi_out_of_ssa): New. (rewrite_reductions_out_of_ssa): New. (build_poly_scop): Call rewrite_reductions_out_of_ssa. The kernel that is miscompiled looks like this: subroutine diverg ( isum, div, sumd ) integer in, jn, kn parameter(in = 128+5 & , jn = 128+5 & , kn = 128+5) integer is, ie, js, je, ks, ke common /gridcomi/ & is, ie, js, je, ks, ke integer i , j , k real*8 div ( in, jn, kn) sumd = 0.0 if (isum .eq. 1) then do 60 k=ks,ke do 50 j=js,je do 40 i=is,ie sumd = sumd + div(i,j,k) 40 continue 50 continue 60 continue endif return end -- Summary: graphite miscompiles 434.zeusmp of the SPEC 2k6 Product: gcc Version: 4.5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end AssignedTo: spop at gcc dot gnu dot org ReportedBy: spop at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41770