[Bug tree-optimization/66101] New: [5/6 Regression] internal compiler error: in verify_loop_structure, at cfgloop.c:1662

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66101

            Bug ID: 66101
           Summary: [5/6 Regression] internal compiler error: in
                    verify_loop_structure, at cfgloop.c:1662
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

$ ./cc1 -quiet -O2 o.c 
o.c: In function ‘bar’:
o.c:8:5: warning: implicit declaration of function ‘longjmp’
[-Wimplicit-function-declaration]
     longjmp ();
     ^
o.c: In function ‘foo’:
o.c:16:3: warning: implicit declaration of function ‘_setjmp’
[-Wimplicit-function-declaration]
   _setjmp ();
   ^
o.c:29:1: error: size of loop 1 should be 3, not 5
 }
 ^
o.c:29:1: internal compiler error: in verify_loop_structure, at cfgloop.c:1662
0x8437cc verify_loop_structure()
        /home/marek/src/gcc/gcc/cfgloop.c:1662
0xb9b354 loop_optimizer_init(unsigned int)
        /home/marek/src/gcc/gcc/loop-init.c:124
0xc872fa execute
        /home/marek/src/gcc/gcc/predict.c:3056
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.

int a, c, d, e;

int
bar ()
{
  int b = *(long *) 7 == 5 ? : 0;
  if (a || a > b)
    longjmp ();
  return 1;
}

void
foo ()
{
  long f;
  _setjmp ();
  for (; d; c++)
    switch (c)
      case 0:
      {
        f = bar () >> 1;
        if (e)
          goto L;
        if (bar () >> 1)
          goto L;
      }
L:
  ;
}