[Bug c++/105593] [12/13 Regression] avx512 math function raises uninitialized variable warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105593

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
           Keywords|                            |diagnostic, needs-bisection
   Target Milestone|---                         |12.2
             Status|WAITING                     |NEW
             Target|X86_64                      |x86_64-*-*
            Summary|avx512 math function raises |[12/13 Regression] avx512
                   |uninitialized variable      |math function raises
                   |warning                     |uninitialized variable
                   |                            |warning
          Component|target                      |c++

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  We possibly lose the Wno-uninitialized annotation/suppression of
the variable (during inlining?) somewhere.

Simpler testcase:

extern inline __attribute__((__gnu_inline__,__always_inline__))
int foo ()
{
  int r = r;
  return r;
}

void bar (int);

void baz()
{
  int u = foo ();
  bar (u);
}

fails to hide the -Wuninitialized with the C++ frontend, works correct with the
C frontend and on the GCC 11 branch.