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From: "dcb314 at hotmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/109031] csmith: possible bad code with -O2
 -fno-strict-aliasing
Date: Wed, 08 Mar 2023 17:12:25 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109031

--- Comment #18 from David Binderman <dcb314 at hotmail dot com> ---
Part way through reduction, the C code seems to be

int crc32_tab_0;
int crc32_context =3D 0xFFFFFFFFUL;
void main(int , char []) {
  {
    int crc;
    int i;
    i =3D 0;
    for (; i < 256; i++)
      crc32_tab_0 =3D crc;
    {
      { crc32_context =3D 0 ^ crc32_tab_0; }
    }
    printf("...checksum after hashing %s : %lX\n", "g_50",
           crc32_context ^ 0xFFFFFFFFUL);
  }
}

This looks to me like reading rubbish off the local variable stack in main
and then hashing it.

AFAIK not a bug in gcc, but may be a bug in csmith.=