[Bug tree-optimization/71168] New: [7 Regression] ICE in find_uses_to_rename_use (tree-ssa-loop-manip.c:379)

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71168

            Bug ID: 71168
           Summary: [7 Regression] ICE in find_uses_to_rename_use
                    (tree-ssa-loop-manip.c:379)
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

Hi.

Running latest GCC w/ -O3 for:

$ cat tc.i
a, b, c;
long *d;
fn1() {
  for (; 0 < a;)
    a++;
}
fn2() {
  if (b)
    fn3();
  fn1();
}
fn3() {
  for (; c; c++)
    d[c] = 0;
}

$ gcc -O3 tc.i -c

tc.i: In function ‘fn2’:
tc.i:7:1: internal compiler error: Segmentation fault
 fn2() {
 ^~~
0xeaabd6 crash_signal
        ../../gcc/toplev.c:333
0x10662ff gimple_bb
        ../../gcc/gimple.h:1736
0x106897c find_uses_to_rename_use
        ../../gcc/tree-ssa-loop-manip.c:379
0x1068c32 find_uses_to_rename_bb
        ../../gcc/tree-ssa-loop-manip.c:451
0x1068da5 find_uses_to_rename
        ../../gcc/tree-ssa-loop-manip.c:479
0x1069280 rewrite_into_loop_closed_ssa_1(bitmap_head*, unsigned int, int,
loop*)
        ../../gcc/tree-ssa-loop-manip.c:642
0x1069330 rewrite_into_loop_closed_ssa(bitmap_head*, unsigned int)
        ../../gcc/tree-ssa-loop-manip.c:675
0xf6a160 execute
        ../../gcc/tree-loop-distribution.c:1830

Martin