<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/85244>85244</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            missed fold: poisonous vector element
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            llvm:instcombine,
            missed-optimization
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          zhengyang92
      </td>
    </tr>
</table>

<pre>
    https://alive2.llvm.org/ce/z/N3FSo8
https://godbolt.org/z/GMn7sqTxj
```llvm
define <2 x double> @src(double %0, double %1, i1 %2, i1 %3, i1 %4) {
if.end:
 %5 = fadd double %1, -1.0  
  %6 = insertelement <2 x double> poison, double %0, i64 0
  %7 = insertelement <2 x double> %6, double %5, i64 1
  %8 = fadd <2 x double> %7, <double 4.0, double poison>
  ret <2 x double> %8
}

define <2 x double> @tgt(double %0, double %1, i1 %2, i1 %3, i1 %4) {
  %6 = insertelement <2 x double> poison, double %0, i64 0
  %7 = fadd <2 x double> %6, <double 4.0, double poison>
  ret <2 x double> %7
}
```

@jayfoad @regehr 
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy0VEFvnDwQ_TXDxVpkxjYsBw5JNnynr5f2DxiYZR0ZvMUmSvLrKwPpbtJU7SGVVtqxNfP85j1mtPemH4kqULegDomew8lN1cuJxv5Zj32JSeO65-oUwtmDuAGsAWttzSNhau3jkLqpB6xbAqxfAOsvov7q9sAPwG_eFvWua5wNW0HM_e__sfDfvz09rOmQ8_UXcderjo5mJAbiDtkT69zcWAJxz0ByP7WA-_WKASoOeMcuxyweTRZDvITiEkrAkkFxuz5kjimNXeS6HGOCYiAO7Ki77j3sLks5Y1tmvM2XVDN6mgJZGmgMv3I-O-Pd-JblQtrkkvErtOJv0OKrb7HUK1Z2hbW_NPERRBFrQNxtKDK9VnEjLO5f8Sb6mMhmNxSHLfiTd6EPn-jdP7Pgt7LlnyJb8V621-__WkWQ_EE_H53uonAT9XSaWNJVoitFqROqsiLjEssSZXKqRIFCC4VK8n3JG8mLlnKNvFTHTqm8S0yFHCUXmcwUKpRpm6kml8W-bLnUWVOA5DRoY38Od2K8n6naK5Qysboh65dlgbiMqbgxow-tGxozEmD0CxAH4z11O3cOZjAvOpioOsYFM1WxbNfMvQfJrfHBX54KJliq1mJ2dDYO5Kanmz17pDa4iW32JvNk3-2l3oTT3KStGwDrhd76tztP7oHaAFgv3XjAemnoRwAAAP__tx1poQ">