hipFORT examples

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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, target   :: a_h(5,6)    ! host array ('target' is required by c_loc)
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

hipMalloc is also overloaded with source and mold arguments, similar to the ALLOCATE intrinsic. Unlike the array interfaces of the math libraries, the hipMalloc and hipMemcpy overloads are not guarded by USE_FPOINTER_INTERFACES, so they are available in every hipFORT build. 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.

Library examples#

Complete, runnable programs are available for the HIP runtime and the ROCm math libraries:

The hip* libraries offer the same functionality through APIs that follow their NVIDIA counterparts:

hipFFTW instead exposes an FFTW3-compatible API:

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