<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64655>64655</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Miscompile of i1 vector insertelement with avx512f feature
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          jacobly0
      </td>
    </tr>
</table>

<pre>
    ```llvm
target triple = "x86_64"

define i32 @main() "target-features"="+avx512f" { ; no miscompile when disabled
  %1 = alloca <32 x i1>
  store <32 x i1> zeroinitializer, ptr %1
  %2 = load <32 x i1>, ptr %1
  %3 = insertelement <32 x i1> %2, i1 true, i32 1
  store <32 x i1> %3, ptr %1
  %4 = load <32 x i1>, ptr %1
  %5 = bitcast <32 x i1> %4 to i32
 ret i32 %5
}
```
```
$ clang --version
clang version 17.0.0 (https://github.com/llvm/llvm-project.git 8f4dd44097c9ae25dd203d5ac87f3b48f854bba8)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/jacob/.local/lib/dbg/llvm/17.x/bin
$ clang repro.ll && ./a.out; echo $?
0
$ sed -i 's/+/-/' repro.ll
$ clang repro.ll && ./a.out; echo $?
2
```

I notice that it uses a 32-bit stack slot, yet the `insertelement` is lowered to a byte write at byte offset 1.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJykVE2P4zYM_TXMhbBhU_JHDj5sNjXQQ2-9F7JFx9pVrECSJ5n99YXsbGd3MC2wKBA4kkk-PpOPVCGYy8LcQXWC6nxQa5yd776o0Q32tTgMTr92UBf7z9qXKxRnKD5F5S8cMXpzs4wgzghEj7b-q5ZAtPvsT82TWRiNIARZXJVZgFqgYwrYUbKJVVw9hxQpzulJJ_XyqEqagAihOSGIEy4OryaM7nozlvE-84LaBDVY1nsqRKCq3Ngoa92oEMRnQfhAU4L47btTiM7zzyb8xt6ZxUSjrPnGHugz3qLf8H7Apg3bOqXfIX_sLjZ3swT2kS1feYnv0ibMFGxKjH7l7SgIy_-imoD_JaH8NX7V5j6YOKrwATOJ0SU6zwjPce8iVdWzwc35efgukI-vJHG0arlglr2wD8Ytu2F_-XyFZZMXeYFA7RzjLYD4BNQD9RcT53XIR3cF6jcF7n_ZzbsvPMb8YiK2k9RayuLYjEfFVGlNhdCVGttmEoNsp7aSw6CS8Pbcf27SA_EJd9Vm6_J1cfcls2ZZH9llWZ9-s2el8eo02-R9c8E8dtPvS4jKWtZn45MJqJ_dlYH6bXyA-jyJ0Ca-Jl31cHn7hLLJH0D9YJb3VfJ88y63FoFqoBpzoF7lbo1pCHicHQJJEP0e90ORA2vMDAI1YSvdCajPtlPzD-j_S0YfN3gvBy4umpExziqiibgGDqhQUDaYiCGq8SsG62JS42taHjMj1MVP8wF1gSagdXf2rJMAFQ6vkfHuTWRUcb-5aQocscwPuhP6KI7qwF1ZH8tjWci2Pcxdo2Ulm2qUQgz6eKx0IwZRtcSiHaqyrg6mo4JE0ZaiaIq2aHPFU1ONwyQLKUs9TCALvipj89Sw3PnLwYSwclfLuqoOVg1sw7Y2iRa-42ZMu6s6H3y3CXRYLwFkYU2I4Q0lmmi5--Ntk7kpzf8Lj9H5d9vibuKMz1WIzzV5WL3tfm1EgPqNXpLFRv_vAAAA__80hbfN">