<html>
    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Mixing inline and ifunc confuses clang"
   href="https://bugs.llvm.org/show_bug.cgi?id=47691">47691</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Mixing inline and ifunc confuses clang
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>C++
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>rafael@espindo.la
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=24010" name="attach_24010" title="testcas">attachment 24010</a> <a href="attachment.cgi?id=24010&action=edit" title="testcas">[details]</a></span>
testcas

Compile twice with
$ clang++ -Os -S -o test1.s test.cc -DINLINE=
$ clang++ -Os -S -o test2.s test.cc -DINLINE=inline

The first file has the expected result:

_Z9foobarzedPvS_.avx2:                  # @_Z9foobarzedPvS_.avx2
        .cfi_startproc
# %bb.0:
        vlddqu  (%rdi), %ymm0
        vlddqu  (%rsi), %ymm1
        vpcmpgtq        %ymm1, %ymm0, %ymm0
        vpmovmskb       %ymm0, %eax
        vzeroupper
        retq

In the second one it looks like clang sees declarations for the avx functions:

_Z9foobarzedPvS_.avx2:                  # @_Z9foobarzedPvS_.avx2
        .cfi_startproc
# %bb.0:
        pushq   %rbp
        .cfi_def_cfa_offset 16
        .cfi_offset %rbp, -16
        movq    %rsp, %rbp
        .cfi_def_cfa_register %rbp
        pushq   %rbx
        andq    $-32, %rsp
        subq    $224, %rsp
        .cfi_offset %rbx, -24
        movq    %rsi, %rbx
        callq   _ZL18_mm256_lddqu_si256PKDv4_x</pre>
        </div>
      </p>


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