[Bug tree-optimization/42245] New: ICE in verify_backedges for 197.parser with sel-sched

[janis at gcc dot gnu dot org]

GCC trunk gets an internal compiler error when building SPEC CPU2000 test
197.parser with "-O2 -fselective-scheduling -fsel-sched-pipelining" on
powerpc-linux, as demonstrated by this minimized testcase:

-----------------------------------------------------------------------
extern int N_words;
typedef struct DIS_node_struct DIS_node;
typedef struct CON_list_struct CON_list;

struct DIS_node_struct
{
  CON_list *cl;
};

void
build_DIS_CON_tree (void)
{
  int w;
  DIS_node *dnroot, *dn;
  CON_list *child, *xchild;
  for (w = 0; w < N_words; w++)
    {
      if (dnroot == ((void *) 0))
        {
          dnroot = dn;
          for (child = dn->cl; child != ((void *) 0); child = xchild)
            {
            }
        }
    }
}
-----------------------------------------------------------------------

elm3b149% /home/janis/tools/gcc-trunk-anonsvn/bin/gcc -O2
-fselective-scheduling -fsel-sched-pipelining -c bug.c
bug.c: In function ‘build_DIS_CON_tree’:
bug.c:26:1: internal compiler error: in verify_backedges, at
sel-sched-ir.c:3498
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

The failure starts with this very large patch (Expand from SSA):

    http://gcc.gnu.org/viewcvs?view=rev&rev=146817

    r146817 | matz | 2009-04-26 19:35:04 +0000 (Sun, 26 Apr 2009)


-- 
           Summary: ICE in verify_backedges for 197.parser with sel-sched
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: janis at gcc dot gnu dot org
GCC target triplet: powerpc-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42245