<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 - clang does not optimize alignment checks"
   href="https://bugs.llvm.org/show_bug.cgi?id=50421">50421</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>clang does not optimize alignment checks
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>trunk
          </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>LLVM Codegen
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>gonzalo.gadeschi@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Example: <a href="https://godbolt.org/z/G8j6dbG6T">https://godbolt.org/z/G8j6dbG6T</a>

    #include <cstdint>
    bool copy(int* out, int* in) {
        *out = *in;
        return (std::uintptr_t)in % 4 == 0;
    }

does not optimize the alignment check away:

copy(int*, int*):                            # @copy(int*, int*)
        mov     eax, dword ptr [rsi]
        mov     dword ptr [rdi], eax
        test    sil, 3
        sete    al
        ret</pre>
        </div>
      </p>


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      <ul>
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