[Bug tree-optimization/69039] segfault with ftree-parallelize-loops=2

[miyuki at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69039

Mikhail Maltsev <miyuki at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-12-24
                 CC|                            |miyuki at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Mikhail Maltsev <miyuki at gcc dot gnu.org> ---
Reduced testcase:

$ cat ira-color.ii 
typedef unsigned long HARD_REG_SET[8];
int a;
HARD_REG_SET b;
bool c;
long d;
void fn1() {
  for (; a; a++) {
    unsigned long *e = b;
    e[0] |= d;
  }
  unsigned long *y = b;
  c = y[0];
}

$ cc1plus -O2 -ftree-parallelize-loops=2 ira-color.ii
ira-color.ii: In function 'void fn1()':
ira-color.ii:6:6: internal compiler error: Segmentation fault
 void fn1() {
      ^~~

0xcce74f crash_signal
        /home/miyuki/gcc/src/gcc/toplev.c:334
0xe63c9b contains_struct_check(tree_node*, tree_node_structure_enum, char
const*, int, char const*)
        /home/miyuki/gcc/src/gcc/tree.h:3111
0xe63c9b may_propagate_copy(tree_node*, tree_node*)
        /home/miyuki/gcc/src/gcc/tree-ssa-propagate.c:1396
0xd0ace9 gimple_merge_blocks
        /home/miyuki/gcc/src/gcc/tree-cfg.c:1895
0x8f8eb5 merge_blocks(basic_block_def*, basic_block_def*)
        /home/miyuki/gcc/src/gcc/cfghooks.c:774
0xd142b4 cleanup_tree_cfg_bb
        /home/miyuki/gcc/src/gcc/tree-cfgcleanup.c:658
0xd14c56 cleanup_tree_cfg_1
        /home/miyuki/gcc/src/gcc/tree-cfgcleanup.c:724
0xd14c56 cleanup_tree_cfg_noloop
        /home/miyuki/gcc/src/gcc/tree-cfgcleanup.c:759
0xd14c56 cleanup_tree_cfg()
        /home/miyuki/gcc/src/gcc/tree-cfgcleanup.c:810
0xbcb761 execute_expand_omp
        /home/miyuki/gcc/src/gcc/omp-low.c:13384
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