直接将PGI OpenACC运行库与gcc链接

我习惯于直接从GCC编译的代码中使用PGI OpenACC运行时API

我注意到PGI OpenACC安装提供了两个OpenACC.h头文件。一个用于位于include/openacc.h中的PGI，另一个似乎与GCC etc/include_acc/openacc.h兼容。将第二个标头与GCC一起使用是否安全

到目前为止，我已经能够编译并运行一个小测试：

#include <openacc.h>
#include <cuda_runtime_api.h>
#include <stdio.h>

int main()
{
   acc_init( acc_device_nvidia );

   int ndev = acc_get_num_devices( acc_device_nvidia );

   printf("Num OpenACC devices: %d\n", ndev);

   cudaGetDeviceCount(&ndev);

   printf("Num CUDA devices: %d\n", ndev);

   return 0;
}

更多信息：

$ ldd oacc_test.pgi 
    linux-vdso.so.1 (0x00007ffd843f8000)
    libaccapi.so => /usr/local/pgi/linux86-64/17.4/lib/libaccapi.so (0x00007fa5a2b9f000)
    libaccg.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg.so (0x00007fa5a2981000)
    libaccnc.so => /usr/local/pgi/linux86-64/17.4/lib/libaccnc.so (0x00007fa5a2777000)
    libaccn.so => /usr/local/pgi/linux86-64/17.4/lib/libaccn.so (0x00007fa5a2552000)
    libaccg2.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg2.so (0x00007fa5a233c000)
    libcudapgi.so => /usr/local/pgi/linux86-64/17.4/lib/libcudapgi.so (0x00007fa5a213b000)
    libcudart.so.8.0 => /usr/local/cuda/lib64/libcudart.so.8.0 (0x00007fa5a1ed5000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fa5a1b49000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fa5a1945000)
    libcudadevice.so => /usr/local/pgi/linux86-64/17.4/lib/libcudadevice.so (0x00007fa5a1731000)
    libpgmp.so => /usr/local/pgi/linux86-64/17.4/lib/libpgmp.so (0x00007fa5a14af000)
    libnuma.so => /usr/local/pgi/linux86-64/17.4/lib/libnuma.so (0x00007fa5a12ae000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fa5a1091000)
    libpgc.so => /usr/local/pgi/linux86-64/17.4/lib/libpgc.so (0x00007fa5a0dae000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fa5a0aaa000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fa5a070b000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fa5a04f2000)
    /lib64/ld-linux-x86-64.so.2 (0x000055767be3b000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fa5a02ea000)

$ ldd oacc_test.both 
    linux-vdso.so.1 (0x00007ffe55753000)
    libcudart.so.8.0 => /usr/local/cuda/lib64/libcudart.so.8.0 (0x00007f7ddfe3c000)
    libcuda.so.1 => /usr/lib/x86_64-linux-gnu/libcuda.so.1 (0x00007f7ddf3d8000)
    libaccapi.so => /usr/local/pgi/linux86-64/17.4/lib/libaccapi.so (0x00007f7ddf1b8000)
    libaccg.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg.so (0x00007f7ddef9a000)
    libaccnc.so => /usr/local/pgi/linux86-64/17.4/lib/libaccnc.so (0x00007f7dded90000)
    libaccn.so => /usr/local/pgi/linux86-64/17.4/lib/libaccn.so (0x00007f7ddeb69000)
    libaccg2.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg2.so (0x00007f7dde955000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f7dde751000)
    libpgc.so => /usr/local/pgi/linux86-64/17.4/lib/libpgc.so (0x00007f7dde46e000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f7dde16a000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f7ddddcb000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f7dddbac000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f7ddd9a4000)
    libnvidia-fatbinaryloader.so.378.13 => /usr/lib/x86_64-linux-gnu/libnvidia-fatbinaryloader.so.378.13 (0x00007f7ddd753000)
    /lib64/ld-linux-x86-64.so.2 (0x00005593f06f5000)

$ ldd oacc_test.gnu 
    linux-vdso.so.1 (0x00007ffd967d7000)
    libcudart.so.8.0 => /usr/local/cuda/lib64/libcudart.so.8.0 (0x00007f9002679000)
    libcuda.so.1 => /usr/lib/x86_64-linux-gnu/libcuda.so.1 (0x00007f9001c15000)
    libgomp.so.1 => /usr/lib/x86_64-linux-gnu/libgomp.so.1 (0x00007f90019e8000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f90017cb000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f900142c000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f9001226000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f900101e000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f9000d1a000)
    libnvidia-fatbinaryloader.so.378.13 => /usr/lib/x86_64-linux-gnu/libnvidia-fatbinaryloader.so.378.13 (0x00007f9000ac9000)
    /lib64/ld-linux-x86-64.so.2 (0x0000563eee684000)

这样使用PGI OpenACC运行时API安全吗

另外，Nvidia通常在/usr/local/CUDA中提供的CUDA运行时与PGI在/usr/local/PGI/linux86-64/2017/CUDA中提供的运行时有什么区别？

---

我注意到pgcc从自己的安装路径中使用CUDA7.5，但当提供-ta=cuda8.0时，它使用/usr/local/CUDA中的一个。有什么特殊原因吗？

PGI编译对象可以与GNU互操作，可以将PGI OpenACC编译代码与GNU编译对象混合使用。不过，OpenACC运行时库不兼容，所以我建议不要混合使用OpenACC代码。请注意，GNU对OpenACC的支持在其7.0版本中得到了很大改善，因此，当我为PGI工作时，我鼓励您尝试这两种编译器。需要注意的一点是，GNU不支持内核构造，因此您需要坚持使用并行区域

至于CUDA库，PGI提供了编译OpenACC代码所需的所有库。尽管如此，CUDA图书馆本身并没有什么不同。我们不希望用户必须共同安装CUDA SDK，它允许我们添加方便标志，例如-Mcudalib[=cublas | cuft | curand | cusolver | cusparse]，因为我们知道这些库的位置，并且在这些库中包含我们自己的Fortran接口模块

除非在编译行上设置了标志CUDAROOT=，否则，-ta=tesla:cuda8.0应该使用PGI提供的CUDA 8.0目录，该目录位于$PGI/linux86-64/2017/CUDA/8.0中。您确定它正在使用/usr/local/cuda安装吗？您可以通过添加verbose标志-v来查看编译器驱动程序正在执行什么，或者通过添加-dryrun来查看命令，而无需驱动程序执行它们

---

另一种可能是使用-L或-Wl标志指向CUDA安装，就像使用GNU一样，在这种情况下，链接器将从这些目录中拾取CUDA库。虽然它们和我们提供的是同一个库，但这不应该是一个问题

谢谢！，我将检查gcc 7.0。关于CUDA 8.0目录的事情。。。这是我的错，因为LD_LIBRARY_PATH设置为：/usr/local/cuda/lib64

$ ldd oacc_test.pgi 
    linux-vdso.so.1 (0x00007ffd843f8000)
    libaccapi.so => /usr/local/pgi/linux86-64/17.4/lib/libaccapi.so (0x00007fa5a2b9f000)
    libaccg.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg.so (0x00007fa5a2981000)
    libaccnc.so => /usr/local/pgi/linux86-64/17.4/lib/libaccnc.so (0x00007fa5a2777000)
    libaccn.so => /usr/local/pgi/linux86-64/17.4/lib/libaccn.so (0x00007fa5a2552000)
    libaccg2.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg2.so (0x00007fa5a233c000)
    libcudapgi.so => /usr/local/pgi/linux86-64/17.4/lib/libcudapgi.so (0x00007fa5a213b000)
    libcudart.so.8.0 => /usr/local/cuda/lib64/libcudart.so.8.0 (0x00007fa5a1ed5000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fa5a1b49000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fa5a1945000)
    libcudadevice.so => /usr/local/pgi/linux86-64/17.4/lib/libcudadevice.so (0x00007fa5a1731000)
    libpgmp.so => /usr/local/pgi/linux86-64/17.4/lib/libpgmp.so (0x00007fa5a14af000)
    libnuma.so => /usr/local/pgi/linux86-64/17.4/lib/libnuma.so (0x00007fa5a12ae000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fa5a1091000)
    libpgc.so => /usr/local/pgi/linux86-64/17.4/lib/libpgc.so (0x00007fa5a0dae000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fa5a0aaa000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fa5a070b000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fa5a04f2000)
    /lib64/ld-linux-x86-64.so.2 (0x000055767be3b000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fa5a02ea000)

$ ldd oacc_test.both 
    linux-vdso.so.1 (0x00007ffe55753000)
    libcudart.so.8.0 => /usr/local/cuda/lib64/libcudart.so.8.0 (0x00007f7ddfe3c000)
    libcuda.so.1 => /usr/lib/x86_64-linux-gnu/libcuda.so.1 (0x00007f7ddf3d8000)
    libaccapi.so => /usr/local/pgi/linux86-64/17.4/lib/libaccapi.so (0x00007f7ddf1b8000)
    libaccg.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg.so (0x00007f7ddef9a000)
    libaccnc.so => /usr/local/pgi/linux86-64/17.4/lib/libaccnc.so (0x00007f7dded90000)
    libaccn.so => /usr/local/pgi/linux86-64/17.4/lib/libaccn.so (0x00007f7ddeb69000)
    libaccg2.so => /usr/local/pgi/linux86-64/17.4/lib/libaccg2.so (0x00007f7dde955000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f7dde751000)
    libpgc.so => /usr/local/pgi/linux86-64/17.4/lib/libpgc.so (0x00007f7dde46e000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f7dde16a000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f7ddddcb000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f7dddbac000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f7ddd9a4000)
    libnvidia-fatbinaryloader.so.378.13 => /usr/lib/x86_64-linux-gnu/libnvidia-fatbinaryloader.so.378.13 (0x00007f7ddd753000)
    /lib64/ld-linux-x86-64.so.2 (0x00005593f06f5000)

$ ldd oacc_test.gnu 
    linux-vdso.so.1 (0x00007ffd967d7000)
    libcudart.so.8.0 => /usr/local/cuda/lib64/libcudart.so.8.0 (0x00007f9002679000)
    libcuda.so.1 => /usr/lib/x86_64-linux-gnu/libcuda.so.1 (0x00007f9001c15000)
    libgomp.so.1 => /usr/lib/x86_64-linux-gnu/libgomp.so.1 (0x00007f90019e8000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f90017cb000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f900142c000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f9001226000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f900101e000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f9000d1a000)
    libnvidia-fatbinaryloader.so.378.13 => /usr/lib/x86_64-linux-gnu/libnvidia-fatbinaryloader.so.378.13 (0x00007f9000ac9000)
    /lib64/ld-linux-x86-64.so.2 (0x0000563eee684000)