[Bug tree-optimization/103710] Missed optimization: common bit prefix/suffixes of multiple values

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103710

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-12-14
     Ever confirmed|0                           |1

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Here is another function which should produce the same code:

unsigned char fctn1(unsigned int z) noexcept
{
    switch(z)
    {
        case 0x0e000000 ... 0x0fffffff:
          return 1;
        case 0x60000000 ... 0x67ffffff:
          return 1;
        case 0x7c000000 ... 0x7fffffff:
          return 1;
    }
  return 0;
}

I think GCC produces non-optimial code for all cases even.