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    <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 - Link error about __atomic_* when -fopenmp enabled"
   href="https://bugs.llvm.org/show_bug.cgi?id=38026">38026</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Link error about __atomic_* when -fopenmp enabled
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libraries
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>6.0
          </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>Common Code Generator Code
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>m-takahiro@jp.fujitsu.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>When a following code is compiled with -fopenmp for x86 and aarch64 targets,
link error occurs.

------ complex.c --------
#include <complex.h>
void foo() {
  double _Complex x, v, expr;
#pragma omp atomic write
  x = 1 + I * 1.0;
#pragma omp atomic read
  expr = x;
#pragma omp atomic update
  x = x + expr;
#pragma omp atomic capture
  {
    v = x;
    x = x + expr;
  }
#pragma omp atomic capture
  {
    x = x + expr;
    v = x;
  }
}
-------------------------

For x86 target:

$ clang -O0 complex.c -fopenmp
/usr/lib/gcc/x86_64-redhat-linux/4.8.5/../../../../lib64/crt1.o: In function
`_start':
(.text+0x20): undefined reference to `main'
/tmp/complex-eb77c9.o: In function `foo':
complex.c:(.text+0x2f): undefined reference to `__atomic_store'
complex.c:(.text+0x45): undefined reference to `__atomic_load'
complex.c:(.text+0x89): undefined reference to `__atomic_load'
complex.c:(.text+0xd5): undefined reference to `__atomic_compare_exchange'
complex.c:(.text+0x112): undefined reference to `__atomic_load'
complex.c:(.text+0x17d): undefined reference to `__atomic_compare_exchange'
complex.c:(.text+0x1d7): undefined reference to `__atomic_load'
complex.c:(.text+0x245): undefined reference to `__atomic_compare_exchange'

For aarch64 target:

$ clang -fopenmp complex.c
/usr/lib/gcc/aarch64-redhat-linux/4.8.5/../../../../lib64/crt1.o: In function
`_start':
(.text+0x30): undefined reference to `main'
/tmp/complex-b0efaa.o: In function `foo':
complex.c:(.text+0x68): undefined reference to `__atomic_store'
complex.c:(.text+0x7c): undefined reference to `__atomic_load'
complex.c:(.text+0xbc): undefined reference to `__atomic_load'
complex.c:(.text+0x10c): undefined reference to `__atomic_compare_exchange'
complex.c:(.text+0x13c): undefined reference to `__atomic_load'
complex.c:(.text+0x194): undefined reference to `__atomic_compare_exchange'
complex.c:(.text+0x1e0): undefined reference to `__atomic_load'
complex.c:(.text+0x238): undefined reference to `__atomic_compare_exchange'</pre>
        </div>
      </p>


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