<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/91431>91431</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Regression on trunk: missed optimization for dead code, work as expected on clang-18
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          ZY546
      </td>
    </tr>
</table>

<pre>
    Reduced code:
https://godbolt.org/z/chrT7v9vo

```cpp
int m;
void func(short a, short b) {
    short f = 1;
    if(
    (f ? ((a ? b : 0) ? 1 : 0) : 0)
    -
    (f ? ((a ? b : 0) ? 1 : 0) : 0)
    ){ 
        m=1;
 }
}
```
Clang-trunk:
```asm
func(short, short): # @func(short, short)
        test    si, si
 setne   al
        sete    cl
        test    di, di
        setne dl
        sete    sil
        and     dl, al
        or      sil, cl
        cmp     dl, sil
        jne     .LBB0_2
        mov dword ptr [rip + m], 1
.LBB0_2:                                # %if.end
        ret
```

Expected code (Clang-18.1.0):
```asm
func(short, short): # @func(short, short)
        ret
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy0VM1yozgQfprm0mVKSGDMgYOJl9OeUnvZvWwJSdhKAFGScGby9FMC_BMnuc1QFPTP1x-t7qa5c_o4KFVCVkF2iPjkT8aW__2bpduoMfJn-azkJJREYaQCtgdyALI_eT-6oNEaaH00sjGdj409Aq3fgdbiZP_Jz8XZLPD1uSXLLcZxsejBYw-sWrSz0RLbaRBAd-5krEcO9AkXsQFaIOQrFBFXe4vADphcSYJHt0B3NxXoLqDqIADd8VluENgeyczKakzu1UW4EWx-I1dQ8gpvhnD1wA53R4D8sFbsKlxKt6hPHR-OG2-n4fXakiuEu36x3JfyWsjwfbZHoAwhJd9CPqTnlfNzxfWM0avXKT8oROTdR7hTPphRdF_TyJlG6k9Rg0L5DZfTDw4-yPktu0D2mIKxa7ie3Y-ZiH68C_7E_TIfCzH-u6rI__ShV-aM8s1YiaO3CFll9YhAK-whOwS6ZMFfgtk18rtr7gXNdBurQX78mFX-ywFYnn_9GJXw678ZJnKZi2QXJzFZGv3HZ-NzhpEsmSxYwSNVJnmSJWmS0m10Ktt81yiS8rQgYpu3ebsVCS1o1mZKtqxpI11SQlOSkR1JE0K3MUsLxgTnLSPbQrYFpET1XHdx1537sG4i7dykyiJJWRJ1vFGdmzcZpYN6w9kJlIbFZssQs2mmo4OUdNp5d2Px2neqfFZHq5zTZkAz4OXvwl47pySa0etev3Mf_K2xKBVftyJ9wjdjX5E7VJeWmAHF2o1osl35sDG1P01NLEwPtA5prK_NaM2LEh5oPSfvgNbz4X4FAAD__0C4fQY">