hipFORT examples

Use the following examples to express Fortran 2003 (f2003) interfaces:

Example 1

use iso_c_binding
use hipfort
integer     :: ierr        ! error code
real        :: a_h(5,6)    ! host array
type(c_ptr) :: a_d         ! device array pointer
!
ierr = hipMalloc(a_d,size(a_h)*4_c_size_t) ! real has 4 bytes
                                       ! append suffix '_c_size_t' to write '4'
                                       ! as 'integer(c_size_t)'
ierr = hipMemcpy(a_d,c_loc(a_h),size(a_h)*4_c_size_t,hipMemcpyHostToDevice)

Example 2

use hipfort
integer     :: ierr        ! error code
real        :: a_h(5,6)    ! host array
real,pointer :: a_d(:,:)   ! device array pointer
!
ierr = hipMalloc(a_d,shape(a_h))      ! or hipMalloc(a_d,[5,6]) or hipMalloc(a_d,5,6) or hipMalloc(a_d,mold=a_h)
ierr = hipMemcpy(a_d,a_h,size(a_h),hipMemcpyHostToDevice)

Note

The Fortran 2008 (f2008) interfaces also overload hipMalloc, similar to the Fortran 2008 ALLOCATE intrinsic. For example:

integer     :: ierr        ! error code
real        :: a_h(5,6)    ! host array
real,pointer :: a_d(:,:)   ! device array pointer
!
ierr = hipMalloc(a_d,source=a_h)       ! take shape (incl. bounds) of a_h and perform a blocking copy to device

In addition to source, there is also dsource, which is used if the source is a device array.