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From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/105651] [12/13 Regression] bogus "may
 overlap" memcpy warning with std::string and operator+ at -O3
Date: Fri, 08 Jul 2022 11:56:08 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105651

Martin Li=C5=A1ka <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|needs-bisection,            |
                   |needs-reduction             |
                 CC|                            |aldyh at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org

--- Comment #8 from Martin Li=C5=A1ka <marxin at gcc dot gnu.org> ---
Started with r12-3347-g8af8abfbbace49e6 where new warning appeared:

    inlined from =E2=80=98std::string f()=E2=80=99 at pr105651.C:5:32:
/dev/shm/gcc-bisect-bin/usr/local/include/c++/12.0.0/bits/char_traits.h:355=
:56:
error: =E2=80=98void* __builtin_memcpy(void*, const void*, long unsigned in=
t)=E2=80=99
specified bound between 9223372036854775810 and 18446744073709551615 exceeds
maximum object size 9223372036854775807 [-Werror=3Dstringop-overflow=3D]
  355 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2,
__n));
      |=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20
~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~=