<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=http://email.email.llvm.org/c/eJyllEFvmzAUxz-NuViNsB0SOHBYk3WHtddJOyETv4JXsBE2bMmn3zPJUkirTtPQw-b5Z_7-P8tQWnXMySYm8Z7En86tP3ag4Jlq4-m41oLTopDe97ocPBQF4SnGCAdv-8LpE2DGNoRnlxD3FzEuUEUboKX2VMxXCMoV-OLQdq10Lw4VwlB4DgrnmduLDsUrEErE5yn2QfC6zCvmm8DYOwSH7ybxOerBD72hi3Gy3d9sxuPjtyciLslbz1PBk9zbCzeAknX8_ktXG5NLO049yF-E7ygoveSu7udcLKk0ak7ZkhqornQBsP55oV92u7_W-Y-uZTPneGxu8LIo9qG9c1t737lghD9gVFaVtvEr21eYnfA2W_bd1F9lFqlcqExkMpKDr22fKznqMHuUxr0co6Fv8hsx7euhXB1si0nTjH-6u663P_CwY6qdGwA35CERGxZHda54ksSpSjIGbPssMpamcsNhy2BdQiqSqJElNC4nyT3h3MBPOkngM0n20f870DmPOUaccCYSHq9ECcBVyQ8yzXgmFR4_aKVuVkEn7FPU55NkOVQOYaOdd69QOqcrAzAZRode-wbyJ1xVm4p2-BMA_GJs53WrT9Jra6LJUT7Z-Q1A5TRB>53610</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Missing pattern optimization
        </td>
    </tr>

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

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

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

<pre>
    `

typedef int v4i32 __attribute__((vector_size(16)));
#define bit 3

int get_cmpmasks(int mask)
{
    mask >>= bit;
    mask &= 1;
    mask = -mask;
    return mask;
}`

LLVM:
get_cmpmasks(int):                      # @get_cmpmasks(int)
        mov     eax, edi
        shr     eax, 3
        and     eax, 1
        neg     eax
        ret

GCC:
get_cmpmasks(int):
        mov     eax, edi
        sal     eax, 28
        sar     eax, 31
        ret


https://godbolt.org/z/n71YnhKa9
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyVUsFymzAQ_Rpx0cQDUsDmwKGxmxySXDvTEyMhAWpAYpCgtb--K9l1wMm0U80iafXg6b1luRHHAmUxig8o_nKe3XGQQtZYaYfne0UJLkvm3Kj45GRZIrKDmGXlzFhadZKQJRki-SXow4WMUGBRWmKuHKbLGzxzI11Z9UPP7JsFBn_k957h_Ob2woNheAQj-jXEwRNer3mHSeax5BMEju8C-RIapZtGjVfnaHu4KcbLy7dXRC_JR83BcKD7OKAAGN3Hn390lRFUmjmskv1CZI-lUGvctuMSp2uUabFEkzWqZXNFVwD4Xxp92u__6fM_VbNuiUPb3MBrU8lf5Z3n1rnBeiHkEaIxgpvObczYQHaCR2-T77p9ZnkkCipymrPIKdfJ4lVZq3SDB2hkCX_dDE716sScMjqaxq64YVaunfimMj0kXTf_We6G0fyAzocUCCcJ1XlMaZbEUVvQmrEdF7QiNU3oNq14mqdJXom8zuq6jqOOcdnZAqUPiBAtf-JAAXuUHiJVkJhAxClJaEriDeVSEsFJxXY5yZmATpI9U93G6_CWo7EIkvjUWAA7ZZ19Bxn4bbSU4TrgZ5NrzVgINitftJlp-3aMgoIiOPgNYB8f7A">