First steps in linking FORTRAN code with C++ and CUDA

Calling function from c++ class from fortran

To do:

• access class variables from fortran

• modify class variables from fortran

This procedure involves the files rism1d.F90 and rism1d_c.cpp. Give the following commands:

• g++ -c rism1d_c.cpp
• gfortran -o testrism1d rism1d.F90 rism1d_c.o -lstdc++

By running ./testrism1d one must get the following output:

kh

Calling fortran function and subrouting (located in a module) from C++

This procedure involves the files test_module.F90, test_module_func.F90 and main_test_module.cpp. Give the following commands:

• gfortran -c test_module.F90
• gfortran -c test_module_func.F90
• g++ -o main main_test_module.cpp test_module.o test_module_func.o -lgfortran

By running ./main one must get the following output:

Calling fortran function from C++!
3
Calling fortran subroutine from C++
   3.0000000000000000

Running .cpp program taht calls CUDA

This procedure involves the files cpp_caller.cpp and test_cuda_c.cu. Give the following commands:

• nvcc -c test_cuda_c.cu
• g++ -o cppcall -L/usr/local/cuda/lib64 -lcuda -lcudart cpp_caller.cpp test_cuda_c.o

By running ./cppcall one must get the following output:

Hello from C++!
Hello from thread 0 at block 0!
Hello from thread 1 at block 0!
Hello from thread 0 at block 1!
Hello from thread 1 at block 1!
The end...

Running .f90 program that calls C++, which calls CUDA

This procedure involves the files test_Cpp_c.cpp, test_C_c.c, test_cuda_c.cu and test.f90. Give the following commands:

• nvcc -c test_cuda_c.cu
• g++ -c test_Cpp_c.cpp
• gcc -c test_C_c.c
• gfortran -o test -L/usr/local/cuda/lib64 -lcuda -lcudart test.f90 test_C_c.o test_Cpp_c.o test_cuda_c.o -lstdc++

By running ./test one must get the following output:

Hello from C!
Hello from C++!
Hello from thread 0 at block 0!
Hello from thread 1 at block 0!
Hello from thread 0 at block 1!
Hello from thread 1 at block 1!