<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/121583>121583</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
[InstCombine] `disjoint` should be dropped in `foldSelectICmpEq`
</td>
</tr>
<tr>
<th>Labels</th>
<td>
miscompilation,
llvm:instcombine
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
dtcxzyw
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
dtcxzyw
</td>
</tr>
</table>
<pre>
Alive2: https://alive2.llvm.org/ce/z/am7W57
```
----------------------------------------
define i32 @src(i32 noundef %x, i32 noundef %y, i32 %c) {
entry:
%xor = xor i32 noundef %y, noundef %x
%cmp = icmp eq i32 %xor, %c
%and = and i32 noundef %x, noundef %y
%or = or disjoint i32 noundef %y, noundef %x
%not = xor i32 %c, 4294967295
%and1 = and i32 %or, %not
%cond = select i1 %cmp, i32 %and, i32 %and1
ret i32 %cond
}
=>
define i32 @src(i32 noundef %x, i32 noundef %y, i32 %c) {
entry:
%or = or disjoint i32 noundef %y, noundef %x
%not = xor i32 %c, 4294967295
%and1 = and i32 %or, %not
ret i32 %and1
}
Transformation doesn't verify!
ERROR: Target is more poisonous than source
Example:
i32 noundef %x = #x0000000f (15)
i32 noundef %y = #x0000000f (15)
i32 %c = #x00000000 (0)
Source:
i32 %xor = #x00000000 (0)
i1 %cmp = #x1 (1)
i32 %and = #x0000000f (15)
i32 %or = poison
i32 %not = #xffffffff (4294967295, -1)
i32 %and1 = poison
i32 %cond = #x0000000f (15)
Target:
i32 %or = poison
i32 %not = #xffffffff (4294967295, -1)
i32 %and1 = poison
Source value: #x0000000f (15)
Target value: poison
Summary:
0 correct transformations
1 incorrect transformations
0 failed-to-prove transformations
0 Alive2 errors
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJy0VVGPmzgQ_jXDi5WVGUNIHnigSSP16aRtpXt2sElcgU1tk0v6608Ghw3b3Wt10qLVEsbzeb75xuPhzqmTlrKE_BMgCl9ff97-AUTI9wkf_NnYMhqToxG3smrVRSKwipy97x2wCvAAeOCj_altL92TsSfAQy0BDz_DUlf8nRdAK1jT-EcroNXqDx-glZCN0pIohgQy6mwNuAkf2gxayIYA5lfAHXllu91tgHkNuCVQfAJaSe3tLTCnFRmhxhJgexLeb-2wiBIxddePGBV-yB_3KFdjA2KMFz25FqNneL_FeREtYiIhY4lQ7rtR2v8RMcBcG7_IZcp8RzLcZtt1gdv8gVe6IDbGjey18XOmJibgZCtrT1Qa838Ql2ux_EpHtJV-JmG0CGUv9uE_2wP7_OF1_Z8qfoCMD0JEcSYhvlmuXWNsx70ymggjnQYsPLlIq5obYDq1yufn57-eQ9N94_YU9nKkM1aS3ihntBkc8WeuiTODrWWEXHnXt3KS47WmI2FAdqXTE6ybNAfc_up8-61zEOe1Ew1OdPIBWn2dmM1kHrruHdB8zGandIy7CHvvrd-wi5EmtV7M9yIHdBOfgH4oMu7I6peQ6Zu7zX3yHplQ77F8Cxk-ltukO7nwdgjqv8stnqvZb94g7DF0HX9pLEpqY224Cfzi9LpxNSVK_9c6JQ1XrRQrb1a9NRf5jtc0Z4i01lj3anYkomRiy7Y8kWVasHyLLKcsOZdZLVPGOBWUUpZK0VCWb4paMlY3Gc-KRJVIMacpZek63yA-1ewoxXGdScnSlNcbyKjsuGrnQZYo5wZZppjmG5a0_ChbF4dlp1xtul61I_EwM3EHiAEJrFLa-dp0R6VlHKe2DEur43BykNFWOe9ewnjl23EKf9HO7yIu3xNY0_vlBWtK3NkMrSBHSYQ1fS8FUTr4NKYVX8f7-cuu6z__gDVNBtuWyyF9Uv48HJ9q0wEeRp7TK1Tiu6w94GFM1wEeYsaXEv8NAAD__1TySk0">