[Bug tree-optimization/77899] incorrect VR_RANGE for a signed char function argument

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77899

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-09-06
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot 
gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1

--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
  p_6 = &d[130] + _1;
  if (&MEM <char[260]> [(void *)&d + 2B] > p_6)

Even this should be folded but is not currently:
void f (signed char i)
{
  char d [260];

  const char *p = &d[130];

  p += i;

  if (p == d + 2 || d + 257 == p)
    __builtin_abort ();
}


I am thinking ptr_difference_const is not able to handle &MEM <char[260]>
[(void *)&d + 2B] correctly.