I have a code that wraps aligned_alloc C function using iso_c_binding in a module. This code, when compiled with gfortran v4.8 and newer, has no issues. However, compiling it with ifort (v17.0.1) produces linkage problems such as: testalign.f90:(.text+0x40): undefined reference to `aligned_alloc' .
As I understand it, aligned_alloc is part of c11 standard so there may be a switch that takes care of this.
So, the question is how to compile the code below with ifort v17?
If this is not possible, is there an Intel Fortran version that supports something like this? Of course, if aligned_alloc is not supported, then I will need to detect a compiler using some ugly preprocessor code and replace aligned_alloc with allocate.
Here's the (almost) minimal example:
module align
implicit none
public !Default access for the module is public .
interface
function aligned_alloc(alg, sz) bind(c)
use, intrinsic :: iso_c_binding
implicit none
integer(kind=c_size_t), intent(in), value :: alg
integer(kind=c_size_t), intent(in), value :: sz
type(c_ptr) :: aligned_alloc
end function aligned_alloc
end interface
contains
subroutine res_align(p, n, alg)
use, intrinsic :: iso_c_binding
implicit none
real(kind=c_double), intent(out), pointer, contiguous :: p(:)
integer, intent(in) :: n
integer, intent(in) :: alg
integer(kind=c_size_t) :: aalg
integer :: bytesz
integer(kind=c_size_t) :: bbytesz
type(c_ptr) :: ptr
bytesz=n*storage_size(p)/8
aalg=int(alg,kind=kind(aalg))
bbytesz=int(bytesz,kind=kind(bbytesz))
ptr=aligned_alloc(aalg,bbytesz)
if (.not. c_associated(ptr)) stop 'error(res_align): unsuccessful allocation'
call c_f_pointer(ptr,p,[n])
end subroutine res_align
end module align
program test
use, intrinsic :: iso_c_binding
use align
implicit none
real(kind=c_double), pointer, contiguous :: parr(:)
integer, parameter :: alg=64
integer, parameter :: sz=399
call res_align(parr,sz,alg)
parr=77.
end program test