[Bug tree-optimization/102805] at -O2, spurious stringop-overflow warning writing to std::vector::back()

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102805

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-10-17
     Ever confirmed|0                           |1
           Keywords|                            |missed-optimization

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to rudick from comment #2)
> Interesting.
> 
> if (f && end > start && start < 100 && end < 100) {
> 
> & I still get the warning though

There is a missed VRP for that case:
Testcase for the above case:
void f1(uint64_t start, uint64_t end)
{
  if (end > start && start < 100 && end < 100)
    {
        uint64_t t = end - start + 1;
        if (t != 0)
          __builtin_abort();
    }
}