[Bug tree-optimization/46352] New: ICE: division by zero with -fdump-tree-tracer

[Bug tree-optimization/46352] New: ICE: division by zero with -fdump-tree-tracer

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46352

           Summary: ICE: division by zero with -fdump-tree-tracer
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz


----- testcase.c -----
void foo (void)
{
  return;
  label:;
}
----------------------

Compiler output:
$ gcc -O -freorder-blocks -ftracer -fdump-tree-tracer testcase.c
testcase.c: In function 'foo':
testcase.c:1:6: internal compiler error: Floating point exception
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r166414 - crash
4.3.5 - crash
4.2.4 - doesn't know -fdump-tree-tracer

[Bug tree-optimization/46352] ICE: division by zero with -fdump-tree-tracer

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46352

--- Comment #1 from Zdenek Sojka <zsojka at seznam dot cz> 2010-12-20 14:12:19 UTC ---
Backtrace for r165699:

The offending line is:
    fprintf (dump_file, "Duplicated %i insns (%i%%)\n", nduplicated,
         nduplicated * 100 / ninsns);


Program received signal SIGFPE, Arithmetic exception.
0x000000000088a835 in tail_duplicate () at /mnt/svn/gcc-trunk/gcc/tracer.c:338
338         fprintf (dump_file, "Duplicated %i insns (%i%%)\n", nduplicated,
(gdb) bt
#0  0x000000000088a835 in tail_duplicate () at
/mnt/svn/gcc-trunk/gcc/tracer.c:338
#1  tracer () at /mnt/svn/gcc-trunk/gcc/tracer.c:364
#2  0x000000000079613f in execute_one_pass (pass=0x155f000) at
/mnt/svn/gcc-trunk/gcc/passes.c:1562
#3  0x00000000007963d5 in execute_pass_list (pass=0x155f000) at
/mnt/svn/gcc-trunk/gcc/passes.c:1617
#4  0x00000000007963e7 in execute_pass_list (pass=0x155fd80) at
/mnt/svn/gcc-trunk/gcc/passes.c:1618
#5  0x00000000008e30f6 in tree_rest_of_compilation (fndecl=0x7ffff5aadf00) at
/mnt/svn/gcc-trunk/gcc/tree-optimize.c:419
#6  0x0000000000aac342 in cgraph_expand_function (node=0x7ffff5acc000) at
/mnt/svn/gcc-trunk/gcc/cgraphunit.c:1494
#7  0x0000000000aae90a in cgraph_expand_all_functions () at
/mnt/svn/gcc-trunk/gcc/cgraphunit.c:1553
#8  cgraph_optimize () at /mnt/svn/gcc-trunk/gcc/cgraphunit.c:1809
#9  0x0000000000aaee6a in cgraph_finalize_compilation_unit () at
/mnt/svn/gcc-trunk/gcc/cgraphunit.c:1016
#10 0x00000000004ab4b4 in c_write_global_declarations () at
/mnt/svn/gcc-trunk/gcc/c-decl.c:9822
#11 0x0000000000889934 in compile_file (argc=16, argv=0x7fffffffdac8) at
/mnt/svn/gcc-trunk/gcc/toplev.c:931
#12 do_compile (argc=16, argv=0x7fffffffdac8) at
/mnt/svn/gcc-trunk/gcc/toplev.c:2363
#13 toplev_main (argc=16, argv=0x7fffffffdac8) at
/mnt/svn/gcc-trunk/gcc/toplev.c:2423
#14 0x00007ffff6371bbd in __libc_start_main () from /lib/libc.so.6
#15 0x00000000004920b9 in _start ()
(gdb) p nduplicated
$1 = 0
(gdb) p ninsns
$2 = <value optimized out>

I can't reproduce it in current trunk, but I don't know if it was fixed or just
hidden.

[Bug tree-optimization/46352] ICE: division by zero with -fdump-tree-tracer

[mpolacek at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46352

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> 2013-04-04 05:37:59 UTC ---
Does not happen anymore, but the issue is maybe still latent; we'd need 3+ BBs
and the sum of insns in them would have to be 0.

[Bug tree-optimization/46352] ICE: division by zero with -fdump-tree-tracer

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46352

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
      Known to work|                            |4.7.0
         Resolution|---                         |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This condition will never happen in 4.7.0+.
Because we will not have the case where we have one BB there:
  if (n_basic_blocks_for_fn (fun) <= NUM_FIXED_BLOCKS + 1)
    return 0;