<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/148052>148052</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Bug in SimplifyCFG causes ICE
        </td>
    </tr>

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

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

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

<pre>
    This minimal Rust code causes a failure when the `simplifycfg` pass is enabled:

```rust
pub fn repro_func(shapes: &mut [ShapeInfo<ReproShape>]) {
 repro_generic::<ReproShape>(shapes);
}

#[derive(Clone)]
pub struct ShapeInfo<S> {
    pub shape: S,
}

#[derive(Default, Copy, Clone)]
pub enum ReproShape {
    #[default]
    A = 0,
    B = 1,
}

pub(crate) fn repro_generic<S: Default + Clone>(shapes: &mut [ShapeInfo<S>]) {
 shapes[0] = shapes[1].clone();
    shapes[1].shape = Default::default();
}
```

When this is compiled with these Rust args:

```
rustc \
--emit=llvm-ir \
--crate-name=repro \
--edition=2021 \
repro.rs \
--crate-type=lib \
--out-dir=out \
--target=x86_64-pc-windows-msvc \
-Cno-prepopulate-passes
```

it produces `repro.ll`.  Rust normally enables `simplifycfg` by default, so I've disabled all passes in this repro.  You can manually reproduce the problem by running `opt --passes=simplifycfg repro.ll`.

I tried to attach `repro.ll`, but GitHub rejects `*.ll` files.  I'll create a repro PR.

</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJx8VE-P-jYQ_TTDZQQyTkLgkAOQ5de9VbuVqp5-cpIJuHLsyH_Y8u0rO4Glu22lSJHGM_PevHm2cE6eNVEFxQGKeiGCvxhbOXkVHUllxaIx3a367SIdDlLLQSh8C85jazrCVgRHDgX2QqpgCT8upNFfCGHDnBxGJftb259hw3AUzqF0SFo0ijrI9sDSt2HTZ4PzwPZjaLDXaGm05mcfdAt86y5iJAfZHoFvhuARisN7jL3q3kB2fIvJKQDZCxQ18B1CeQC2n_ucSZOVbQSN35eCBwDfQRaroKxncjyD4tCRlVcCvj0qoylmFfXM1HkbWo_PZN4he7mjI2LKmpD2-A78-D_9a-pFUB74EY9mvKX_N0jSYcDPAZ6g7t2mJqkghvcIWY1sgo6BQwqsv3AZQwN821rhI97nDh7axcn2OHNE4IeZ3LOC_7mi92-bmSuKA4OiTowekTUU9aqdJt8-thKp_zPFTQJk9Z3VtOC7Ak-185R3r00T_z65VSZftmYYpaIOP6S_RA87mpwu7Nl9dyuwfTRsi1BEFZdLGqSHrFbqOiylfYSTnkstBoKsToJ-VnTSS6Mhqznj6zmcUlbWfWngb9FAtZLN48AEv-ykhaw2Se4p6oU9UyTy13bzc5Mvx3b5IXVnPtxycNcH3aM2y9HSaMagYv94O8l9l0h6HK3pQksu3umJnVKwYSuc5NHGDkKp23yx3b9c_eaG3aezncFX4OWVsJMuvQUolMKJAcp5IxMS4h8mYCs0DkKHBJMOIqH0zozWNIqGCGGD1lKfI74ZPS7vM2X1Ex18nmAa8RW9ldShNyi8F-3ly6CRcxM8_pD-l9CgpT-p9WlM4PspBXupyK0wDaYUtpaEJxQTGv76FqEWXZV1u2wnFlSty4Kvyx3b8MWlyjtar6lv892O5WVe9kWR930nNmtGIt_RQlac8YKVa8YZzzlflWLHc07brCz77TbPIWc0CKlW0X0rY88L6Vygap1vWcEXSjSkXHriOdf0gekUOI8vvq2SZZtwdpAzJZ13n2289IqqQzjHvbzPMh5PP-4v_-vxZRGsqi7ej-mS8BPw01n6S2hWrRmAn2Kv-bccrYniAT8lBg74aaZ4rfjfAQAA__-Sev6Z">