<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/62544>62544</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Wrong code at -Os on x86_64-linux_gnu since Clang-13
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          shao-hua-li
      </td>
    </tr>
</table>

<pre>
    ```console
$ clang-tk -v
clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4c2d29f2fc78782a469ccff625dd29d66d4d9f9b)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /zdata/shaoli/compilers/ccbuilder-compilers
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/10
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/11
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/11
Candidate multilib: .;@m64
Selected multilib: .;@m64
$
$ clang-tk -O0 a.c && ./a.out
3
$ clang-tk -fsanitize=address,undefined a.c && ./a.out
3
$ clang-tk -Os a.c && ./a.out
0
$ clang-12 -Os a.c && ./a.out
3
$
$ cat a.c
int printf(const char *, ...);
int a, b, c;
long d;
int main() {
 short *e = &a;
  int *f = &a;
  *f = 0;
  for (; b <= 9; b++) {
 int **g = &f;
    *f = d;
    *g = &c;
  }
  *e = 3;
 printf("%d\n", a);
}
$
```

Compiler explorer: https://godbolt.org/z/q7e9jnP7v

`opt-bisect-limit` suggests that the issue might be in `DSEPass on main`.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy0VVGvmzgT_TWTFyvIjMHAAw-5ycenfWqlrrSPlbENuHXsLDa3d_vrV4bcJHt11VWlroQSODNz5nhsz4gQzOi0bqF8gvK0E0uc_NyGSfj9tIi9Nbveq79a4HR7pHfBWw30BPQAWBBphRv38SvZP2_gCpBnPQfjHcmrjGaUANZTjJcA7ADYAXajidPSZ9KfATtrn1__9pfZf9EyZqOJpJCosBlwkFVd1SgK3kg5DBxLpbBRnKtCNUPTAzZb7t_FPOoI7EBeav6ZF_vFfXX-m9tb45aX_eiWq980a6HI2Sttk_fFB_OymX5zIQprtTqZOZkAu-9KRAHYpapYA9hJf74Yq-eQ3mW_GKv0vL-jK1HnF6eIFE4ZJaIm_z8eidnIRTTeXcmXMKelmz4VRUrA7ir9Lhm7nP4HnPmv57xuwydttYxa_RJ9x5uy82KjSVHsQDJgT1DQMy_epPyRE2Dx3sH9QInIJAHkgJxkgJ3I_BI3V_ZexBCEM9F818BOQqlZhwB4XJzSg3Fa_Szdh_CDCPo2Isd_iWDvrVbEFLEBxkVymY2LA2CdbnQkchIzATwAHkmWZelGsae7t0h4n37kDbfejUT9w-0sjAOsARsC1RUnYfJzTNyaADslzeIWREgKAzwM79luOH0AB5-E1sCeSE-AHZO9Wb8An9bnMfmVHvAwvmYYHsgecqi38C1APkqqTg_qthWxu_1WVUAELBWUR7e-HlMJ7zW90dw36bXDXj-3s39tKUS_XKyf9dqR3jRSr3pvY-bnMbUqwO7PSjdf3Mfq-ZEJOPWXuO9N0DLurTmbCJySsIyjDjGQOIlI4qSJCWHR5GzGKZJeE-MIcHr69L-PIgTi3bbFnGY71TLVsEbsdJvzmuU1LxjfTW3FVYl5XZU5K4eC6ZJJqmpeYZ6zivb1zrRIkdGSFrQqqpxnMpc1K8qGq1II7BUUVJ-FsVkaCGlhu1VUy7Esip0VvbZhHViITn_bFKcil6fd3K5DpF_GAAW1JsRwZ4kmWt3-MadzK73SRMT1JnlHHvvP59EtJBgnNTluF47tltm2PzfAALtVWJoRq_C_AwAA__-sZyKZ">