<html>
    <head>
      <base href="http://llvm.org/bugs/" />
    </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 --- - Incorrect code of variable arguments"
   href="http://llvm.org/bugs/show_bug.cgi?id=20045">20045</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Incorrect code of variable arguments
          </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>MacOS X
          </td>
        </tr>

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

        <tr>
          <th>Severity</th>
          <td>normal
          </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>ishiura-compiler@ml.kwansei.ac.jp
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Clang 3.5.0 (based on LLVM 3.5svn) for x86_64 target miscompiles the following
code.

    % cat error.c

    #include <stdarg.h>

    struct S { float m0[2]; int m1; };

    void func1( int fx, ... )
    {
        struct S fs;

        va_list ap;
        va_start(ap, fx);
        fs = va_arg(ap, struct S);
        va_end(ap);

        if( fs.m1 != 1 ) { __builtin_abort(); }
    }

    int main( void )
    {
        int x = 1;

        struct S s = {{1.0F,1.0F},1};
        func1(x, s);

        return 0;
    }

    % clang error.c

    % ./a.out
    zsh: abort      ./a.out

    % clang -v
    clang version 3.5.0 (trunk 210625)
    Target: x86_64-apple-darwin13.2.0
    Thread model: posix

The value of fs.m1 was 1065353216 instead of 1.</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>