[Bug tree-optimization/69989] [6 Regression] ICE on x86_64-linux-gnu at -O3 in both 32-bit and 64-bit modes (in verify_loop_structure, at cfgloop.c:1639)

[chengniansun at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69989

Chengnian Sun <chengniansun at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |chengniansun at gmail dot com

--- Comment #6 from Chengnian Sun <chengniansun at gmail dot com> ---
Another example with a similar stack trace. 

$: gcc-trunk -w -O3 small.c
small.c: In function ‘fn1’:
small.c:5:6: error: loop verification on loop tree that needs fixup
 void fn1() {
      ^~~
small.c:5:6: internal compiler error: in verify_loop_structure, at
cfgloop.c:1639
0x72f9f7 verify_loop_structure()
        ../../gcc-source-trunk/gcc/cfgloop.c:1639
0xca037f checking_verify_loop_structure
        ../../gcc-source-trunk/gcc/cfgloop.h:324
0xca037f tree_transform_and_unroll_loop(loop*, unsigned int, edge_def*,
tree_niter_desc*, void (*)(loop*, void*), void*)
        ../../gcc-source-trunk/gcc/tree-ssa-loop-manip.c:1362
0xc07819 tree_predictive_commoning_loop
        ../../gcc-source-trunk/gcc/tree-predcom.c:2530
0xc07819 tree_predictive_commoning()
        ../../gcc-source-trunk/gcc/tree-predcom.c:2565
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
$: 
$: cat small.c
int a, b, d;
short c[] = {4073709551611, 1, 4, 4}

;
void fn1() {
  if (a)
    goto LABEL_vhvhP;
  for (;;) {
    for (; b; b++)
      d = c[b + 3] | c[b];
  LABEL_vhvhP:
    if (d)
      break;
  }
}

int main() { return 0; }