Similar to the tangent-linear model, the transformation for the toy problem

        subroutine head(x,y) 
          double precision,intent(in) :: x
          double precision,intent(out) :: y
          y=sin(x*x)
        end subroutine

leads to a slightly more complex code with additional temporary variables due to possible aliasing. We show colored sections for

• function value, partials and elimination code (one section for plain execution, and one for taping)
  
• adjoint computation
  

Note that the generated code contains sections for argument and result checkpointing. The split reversal, however, does not use  any checkpointing.

       subroutine head(X,Y)
          use OpenAD_dct
          use OpenAD_tape
          use OpenAD_rev
          use OpenAD_checkpoints

          ! original arguments get inserted before version
          ! and declared here together with all local variables
          ! generated by xaifBooster

      use w2f__types
      use active_module
      IMPLICIT NONE
C
C     **** Global Variables ****
C
      REAL(w2f__8) OpenAD_Symbol_0
      REAL(w2f__8) OpenAD_Symbol_1
      REAL(w2f__8) OpenAD_Symbol_2
      REAL(w2f__8) OpenAD_Symbol_3
      REAL(w2f__8) OpenAD_Symbol_4
      REAL(w2f__8) OpenAD_Symbol_5
      type(active) :: OpenAD_Symbol_6
C
C     **** Parameters and Result ****
C
      type(active) :: X
      type(active) :: Y
C
C     **** Local Variables and functions ****
C
      REAL(w2f__8) OpenAD_Symbol_7
C
C     **** statements ****
C


          ! checkpointing stacks and offsets
          integer, parameter :: theMaxStackSize=200

          integer :: cp_loop_variable_1,cp_loop_variable_2,
     +cp_loop_variable_3,cp_loop_variable_4
          ! floats 'F'
          double precision, dimension(theMaxStackSize), save ::
     +theArgFStack
          integer, save :: theArgFStackoffset=0
          double precision, dimension(theMaxStackSize), save ::
     +theResFStack
          integer, save :: theResFStackoffset=0
          ! integers 'I'
          integer, dimension(theMaxStackSize), save ::
     +theArgIStack
          integer, save :: theArgIStackoffset=0
          integer, dimension(theMaxStackSize), save ::
     +theResIStack
          integer, save :: theResIStackoffset=0
          ! booleans 'B'
          logical, dimension(theMaxStackSize), save ::
     +theArgBStack
          integer, save :: theArgBStackoffset=0
          logical, dimension(theMaxStackSize), save ::
     +theResBStack
          integer, save :: theResBStackoffset=0
          ! strings 'S'
          character*(80), dimension(theMaxStackSize), save ::
     +theArgSStack
          integer, save :: theArgSStackoffset=0
          character*(80), dimension(theMaxStackSize), save ::
     +theResSStack
          integer, save :: theResSStackoffset=0

          ! call external C function used in inlined code
          integer iaddr
          external iaddr
          call tape_init

          if (our_rev_mode%arg_store) then
! store arguments
          theArgFStackoffset = theArgFStackoffset+1
          theArgFStack(theArgFStackoffset) = X%v
          end if
          if (our_rev_mode%arg_restore) then
! restore arguments
          X%v = theArgFStack(theArgFStackoffset)
          theArgFStackoffset = theArgFStackoffset-1
          end if
          if (our_rev_mode%plain) then
! original function
      Y%v = SIN(X%v*X%v)

          end if
          if (our_rev_mode%tape) then
! taping
      OpenAD_Symbol_0 = (X%v*X%v)
      OpenAD_Symbol_4 = SIN(OpenAD_Symbol_0)
      OpenAD_Symbol_2 = X%v
      OpenAD_Symbol_3 = X%v
      OpenAD_Symbol_1 = COS(OpenAD_Symbol_0)
      Y%v = OpenAD_Symbol_4
      OpenAD_Symbol_5 = ((OpenAD_Symbol_3 + OpenAD_Symbol_2) *  OpenAD_S
     +ymbol_1)
          double_tape(double_tape_pointer) = OpenAD_Symbol_5
          double_tape_pointer = double_tape_pointer+1

          end if
          if (our_rev_mode%res_store) then
! store results
          theResFStackoffset = theResFStackoffset+1
          theResFStack(theResFStackoffset) = Y%v
          end if
          if (our_rev_mode%res_restore) then
! restore results
          Y%v = theResFStack(theResFStackoffset)
          theResFStackoffset = theResFStackoffset-1
          end if
          if (our_rev_mode%adjoint) then
! adjoint
          double_tape_pointer = double_tape_pointer-1
          OpenAD_Symbol_7 = double_tape(double_tape_pointer)
          OpenAD_Symbol_6%d = OpenAD_Symbol_6%d+Y%d*OpenAD_Symbol_7
          Y%d = 0.0d0
          X%d = X%d+OpenAD_Symbol_6%d
          OpenAD_Symbol_6%d = 0.0d0
          end if
        end subroutine head