Compile Time Actions

• Each parallel region (either found automatically or via directive):

  • is converted into a subroutine call executed by each parallel thread
  • The subroutine contains the execution body of the parallel region
  • the arguments to the subroutine contain scheduling parameters (loop ranges)
  • the new subroutine name:
    • derived from _mpdo_sub_#
    • will appear in the profile
  • data in the parallel region:
    • private data:
      • local (automatic) variables in the newly created subroutine
    • shared data
      • will be passed well known address to the new subroutine

Subroutine daxpy(n,a,x,y)

real*8 a,x(n),y(n)

do I=1,n

y(I) = y(I)+a*x(I)

enddo

end

Subroutine daxpy(n,a,x,y)

real*8 a,x(n),y(n)

integer*4 args

_LOCAL_NTRIP = n/__mp_sug_numthreads_func$()

_LOCAL_START = 1+__mp_my_thread_id()*_LOCAL_NTRIP

_INCR = 1

args(1) = _LOCAL_START

args(2) = _LOCAL_NTRIP

args(3) = _INCR

args(4) = 0

call sproc$(_mpdo_daxpy_1,%VAL(PR_SALL),args)

END

subroutine _mpdo_daxpy_1(_LOCAL_START,

_LOCAL_NTRIP,_INCR,_INF)

do I=_LOCAL_START,_LOCAL_NTRIP

y(I) = y(I)+a*x(I)

enddo

end

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