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      <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 - CUDA separable compilation support"
   href="https://bugs.llvm.org/show_bug.cgi?id=49555">49555</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>CUDA separable compilation support
          </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>CUDA
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>carlosgalvezp@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Hi!

Since long time ago CUDA supports separable compilation:
<a href="https://developer.nvidia.com/blog/separate-compilation-linking-cuda-device-code/">https://developer.nvidia.com/blog/separate-compilation-linking-cuda-device-code/</a>

Is this expected to be supported in Clang? The following example doesn't work:

// lib.h
__device__ int foo();

// lib.cu
#include "lib.h"
__device__ int foo()
{
    return 123;
}

// main.cu
#include "lib.h"

#include <cstdio>

__global__ kernel()
{
    printf("%d\n", foo());
}

int main()
{
   kernel<<<1,10>>>();
   cudaDeviceSynchronize();
}


Compiling with:

clang++ ... lib.cu main.cu

Gives a linker error: cannot find reference to extern function "foo".

If this is not supported out of the box, would the following procedure be
reasonable?

1) Compile object files with clang, adding -fgpu-rdc.
2) Device link them using "nvcc -dlink *.o -o device_link.o"
3) Link everything with clang: "clang *.o device_link.o"

Thanks!</pre>
        </div>
      </p>


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