[Bug debug/49522] Divide by zero in validate_subreg in emit-rtl.c:695

["ramana at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49522

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.07.01 16:35:45
                 CC|                            |ramana at gcc dot gnu.org
          Component|middle-end                  |debug
     Ever Confirmed|0                           |1

--- Comment #1 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> 2011-07-01 16:35:45 UTC ---

bt
#0  0x08270d79 in validate_subreg (omode=VOIDmode, imode=SImode,
reg=0xb7dae7e8, offset=0) at
/home/ramrad01/sources/fsf/trunk/gcc/emit-rtl.c:695
#1  0x08270fa0 in gen_rtx_SUBREG (mode=VOIDmode, reg=0xb7dae7e8, offset=0) at
/home/ramrad01/sources/fsf/trunk/gcc/emit-rtl.c:775
#2  0x08271027 in gen_lowpart_SUBREG (mode=VOIDmode, reg=0xb7dae7e8) at
/home/ramrad01/sources/fsf/trunk/gcc/emit-rtl.c:790
#3  0x0821c879 in dead_debug_insert_before (all_blocks=0x8dc1364) at
/home/ramrad01/sources/fsf/trunk/gcc/df-problems.c:3197
#4  df_note_bb_compute (all_blocks=0x8dc1364) at
/home/ramrad01/sources/fsf/trunk/gcc/df-problems.c:3399
#5  df_note_compute (all_blocks=0x8dc1364) at
/home/ramrad01/sources/fsf/trunk/gcc/df-problems.c:3452
#6  0x08215c16 in df_analyze_problem (dflow=0x8ddf078,
blocks_to_consider=0x8dc1364, postorder=0x8dc6ad0, n_blocks=3) at
/home/ramrad01/sources/fsf/trunk/gcc/df-core.c:1152
#7  0x08215e6b in df_analyze () at
/home/ramrad01/sources/fsf/trunk/gcc/df-core.c:1249
#8  0x08919a8b in sched_init () at
/home/ramrad01/sources/fsf/trunk/gcc/haifa-sched.c:3487
#9  0x08920472 in haifa_sched_init () at
/home/ramrad01/sources/fsf/trunk/gcc/haifa-sched.c:3526
#10 0x084b87aa in schedule_insns () at
/home/ramrad01/sources/fsf/trunk/gcc/sched-rgn.c:3302
#11 0x084b8e3d in rest_of_handle_sched2 () at
/home/ramrad01/sources/fsf/trunk/gcc/sched-rgn.c:3532
#12 0x0845bb99 in execute_one_pass (pass=0x8c2fd20) at
/home/ramrad01/sources/fsf/trunk/gcc/passes.c:2059
#13 0x0845becd in execute_pass_list (pass=0x8c2fd20) at
/home/ramrad01/sources/fsf/trunk/gcc/passes.c:2114
#14 0x0845bee0 in execute_pass_list (pass=0x8c2f6a0) at
/home/ramrad01/sources/fsf/trunk/gcc/passes.c:2115
#15 0x0845bee0 in execute_pass_list (pass=0x8c2f660) at
/home/ramrad01/sources/fsf/trunk/gcc/passes.c:2115
#16 0x08575621 in tree_rest_of_compilation (fndecl=0xb7d71c00) at
/home/ramrad01/sources/fsf/trunk/gcc/tree-optimize.c:416
#17 0x081f8482 in cgraph_expand_function (node=0xb7cfd668) at
/home/ramrad01/sources/fsf/trunk/gcc/cgraphunit.c:1792
#18 0x081fa41d in cgraph_expand_all_functions () at
/home/ramrad01/sources/fsf/trunk/gcc/cgraphunit.c:1851
#19 cgraph_optimize () at
/home/ramrad01/sources/fsf/trunk/gcc/cgraphunit.c:2121
#20 0x081fab55 in cgraph_finalize_compilation_unit () at
/home/ramrad01/sources/fsf/trunk/gcc/cgraphunit.c:1292
#21 0x080d4090 in c_write_global_declarations () at
/home/ramrad01/sources/fsf/trunk/gcc/c-decl.c:9844
#22 0x08508bc4 in compile_file (argc=5, argv=0xbffff394) at
/home/ramrad01/sources/fsf/trunk/gcc/toplev.c:571
#23 do_compile (argc=5, argv=0xbffff394) at
/home/ramrad01/sources/fsf/trunk/gcc/toplev.c:1908
#24 toplev_main (argc=5, argv=0xbffff394) at
/home/ramrad01/sources/fsf/trunk/gcc/toplev.c:1980
#25 0x081740cb in main (argc=5, argv=0xbffff394) at
/home/ramrad01/sources/fsf/trunk/gcc/main.c:36
(gdb) 


It appears as though we are attempting to create a subreg of a clobber
(const_int 0) . 


Ramana