[Bug middle-end/123355] clang: 6 * -Wmaybe-uninitialized

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123355

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2026-01-02

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
>../../trunk/gcc/config/i386/i386-options.cc:2956:20: warning: ‘mask’ may be 
>used uninitialized [-Wmaybe-uninitialized]

Is definitely incorrect.
we have:
if (d())
 mask = z;
else {
  for (i = 0; i < ARRAY_SIZE (recip_options); i++)
    if (b(i))
      mask = x;
  if (i == ARRAY_SIZE (recip_options))
    {
      error();
      mask = y;
    }
}

I wonder if we should rearrange the code so the default for mask is y and
remove the setting of mask in the error case.
This won't change anything except fix the warning I think.

>
../../trunk/gcc/tree-vect-generic.cc:587:16: warning: ‘first_cst’ may be used
uninitialized [-Wmaybe-uninitialized]

This is a false warning also:
uniform_const_p = true;
for (i = 0; i < N ; i++)
  if (uniform_const_p && x())
  {
    if (i == 0)
      first_cst = x;
    else if (a(first_cst))
  }
  else
    uniform_const_p = false;