<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 - wrong code at -O2 on x86_64-linux-gnu"
   href="https://bugs.llvm.org/show_bug.cgi?id=50621">50621</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>wrong code at -O2 on x86_64-linux-gnu
          </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>All
          </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>qrzhang@gatech.edu
          </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>It appears to be a recent regression.


$ clang-trunk -v
clang version 13.0.0 (<a href="https://github.com/llvm/llvm-project.git">https://github.com/llvm/llvm-project.git</a>
61a2d6bfe48cf3da4b95d1383bf866690287f8e8)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin


$ clang-trunk abc.c ; ./a.out
0


$ clang-trunk -O2 abc.c ; ./a.out
1


$ cat abc.c
short b, e;
int c, d, g;
int f[] = {2, 6, 0, 4};
void(h)();
int main() {
  short a[] = {3, 2, 3};
  f[2] = h || b;
  for (; g <= 1; g++) {
    e = 3;
    for (; e; e--) {
      d = 1;
      if (a[g] < f[e])
        d = a[g + 1] = c;
      else
        break;
    }
  }
  printf("%d\n", d);
}</pre>
        </div>
      </p>


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      <ul>
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