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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c/102291] [9/10/11/12 Regression] wrong overflow warning for
 compound expression conversion and bit_and expressions
Date: Sat, 11 Sep 2021 19:33:23 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102291

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|dubious overflow warning    |[9/10/11/12 Regression]
                   |                            |wrong overflow warning for
                   |                            |compound expression
                   |                            |conversion and bit_and
                   |                            |expressions
      Known to work|9.4.0                       |4.1.2
      Known to fail|                            |4.4.7
   Target Milestone|---                         |9.5

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I don't think this really a regression from GCC 9 but rather a regression f=
rom
a long time ago.
Take:
typedef unsigned long ulong;
typedef unsigned char uchar;


ulong testera(ulong ul) {
    return ((((uchar) (((void)0, ((uchar) (0x80)))|0)) & 0x3f));
}
----- CUT ----
This is slightly different from your teststcase but it warns all the way ba=
ck
until sometime before 4.4.0 (I only can test 4.1.2).=