[Bug middle-end/18861] New: [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637

[Bug middle-end/18861] New: [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637

[belyshev at lubercy dot com]

use '-O2 -finline-functions -ftracer -floop-optimize2' to reproduce:
----------------------------------------------------------------------------------------
extern void fancy_abort (void) __attribute__ ((__noreturn__));

int
reverse_condition (int code)
{
  switch (code)
    {
    case 4:
      return 3;
    case 3:
      return 4;
    case 6:
      return 7;
    case 7:
      return 8;
    case 8:
      return 5;
    case 5:
      return 6;

    default:
      fancy_abort ();
    }
}

int
reversed_comparison_code_parts (int code, int code2)
{
  switch (code)
    {
    case 4:
    case 3:
      return reverse_condition (code);
    }

  if (code2 == 1)
    return reverse_condition (code);

  return 0;
}
----------------------------------------------------------------------------------------
backtrace:

Program received signal SIGSEGV, Segmentation fault.
try_crossjump_to_edge (mode=19, e1=0x7, e2=0x40219a08) at
../../gcc/gcc/cfgcleanup.c:1637
1637	      s->count += s2->count;
(gdb) bt
#0  try_crossjump_to_edge (mode=19, e1=0x7, e2=0x40219a08) at
../../gcc/gcc/cfgcleanup.c:1637
#1  0x08178cfa in try_crossjump_bb (mode=19, bb=0x4021acb0) at
../../gcc/gcc/cfgcleanup.c:1810
#2  0x08179acc in cleanup_cfg (mode=19) at ../../gcc/gcc/cfgcleanup.c:1997
#3  0x083b8127 in rest_of_handle_flow2 () at ../../gcc/gcc/passes.c:1322
#4  0x083b8b20 in rest_of_compilation () at ../../gcc/gcc/passes.c:1728
#5  0x080c91aa in execute_pass_list (pass=0x852ba80) at
../../gcc/gcc/tree-optimize.c:516
#6  0x080c93f1 in tree_rest_of_compilation (fndecl=0x4020f244)
    at ../../gcc/gcc/tree-optimize.c:652
#7  0x080615d1 in c_expand_body (fndecl=0x4020f244) at ../../gcc/gcc/c-decl.c:6387
#8  0x083e1167 in cgraph_expand_function (node=0x4020f4fc) at
../../gcc/gcc/cgraphunit.c:822
#9  0x083e1e8b in cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1689
#10 0x0838fa67 in toplev_main (argc=1075931488, argv=0x85d1498) at
../../gcc/gcc/toplev.c:1005
#11 0x080a7bae in main (argc=1075931488, argv=0x40216960) at ../../gcc/gcc/main.c:35

-- 
           Summary: [4.0 Regression] ICE Segmentation fault in
                    try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: belyshev at lubercy dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18861

[Bug middle-end/18861] [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637

[belyshev at lubercy dot com]

------- Additional Comments From belyshev at lubercy dot com  2004-12-06 22:58 -------
: Search converges between 2004-10-25-161001-trunk (#610) and
2004-10-26-161001-trunk (#611).

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18861

[Bug middle-end/18861] [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637 with two switches (table jumps)

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-12-06 23:07 -------
: Search converges between 2004-10-26-161001-trunk (#611) and 2004-11-03-014001-trunk 
(#612).
Confirmed.
Here is a testcase down to one function:
extern void abort (void) __attribute__ ((__noreturn__));
int reversed_comparison_code_parts (int code, int code2)
{
  int D1131;
  if (code >= 3)
  {
    switch (code)
      {
	case 3: return 4; 
	case 4: return 3;
	case 5: return 6;
	case 6: return 7;
	case 7: return 8;
	case 8: return 5;
	default : abort ();
      }
  }  
  switch (code)
    {
      case 3:  return 4;
      case 4:  return 3;
      case 5:  return 6;
      case 6:  return 7;
      case 7:  return 8;
      case 8:  return 5;
      default : abort ();
    }
}

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-12-06 23:07:59
               date|                            |
            Summary|[4.0 Regression] ICE        |[4.0 Regression] ICE
                   |Segmentation fault in       |Segmentation fault in
                   |try_crossjump_to_edge at    |try_crossjump_to_edge at
                   |../../gcc/gcc/cfgcleanup.c:1|../../gcc/gcc/cfgcleanup.c:1
                   |637                         |637 with two switches (table
                   |                            |jumps)
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18861

[Bug rtl-optimization/18861] [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637 with two switches (table jumps)

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-12-08 00:18 -------
"-O2 -floop-optimize2" is enough for the test case in comment 2. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18861

[Bug rtl-optimization/18861] [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637 with two switches (table jumps)

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2004-12-12 05:55 -------
My binary search converges between "2004-11-02 00:20GMT"
and "2004-11-02 00:25GMT".

The following patch has either caused the bug or exposed a latent bug.

Adding Andrew MacLeod to CC.

2004-11-01  Andrew MacLeod  <amacleod@redhat.com>

	PR tree-optimization/16447
	* tree-cfg.c (bsi_commit_one_edge_insert): Rename from
	bsi_commit_edge_inserts_1, and make funtion external.  Return new block.
	(bsi_commit_edge_inserts): Use renamed bsi_commit_one_edge_insert.
	* tree-optimize.c (pass_cleanup_cfg_post_optimizing): Enable listing.
	* tree-flow.h (bsi_commit_one_edge_insert): Extern decl.
	* tree-outof-ssa.c (rewrite_trees): Don't commit edges here.
	(same_stmt_list_p): New.  Return TRUE if edge is to be forwarded.
	(identical_copies_p): New.  Return true is two copies are the same.
	(identical_stmt_lists_p): New.  Return true if stmt lists are the same.
	(analyze_edges_for_bb): New.  Determine how best to insert edge stmts
	for a basic block.
	(perform_edge_inserts): New.  Determine what to do with all stmts that
	have been inserted on edges.
	(remove_ssa_form):  Analyze and commit edges from here.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amacleod at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18861

[Bug rtl-optimization/18861] [4.0 Regression] ICE Segmentation fault in try_crossjump_to_edge at ../../gcc/gcc/cfgcleanup.c:1637 with two switches (table jumps)

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-12-12 10:04 -------
Since the bug is at the RTL level and amacleod's patch only changes things 
at the tree level, that patch probably just uncovered a latent bug. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18861