5. Accessing remote data from task-parallel code segments

• INDEPENDENT DO loop of HPF:

  !HPF$ INDEPENDENT
  
  DO I = 1, 10
  . . .
  ENDDO
  • Variable-uses must have no loop-carried data dependence—can execute in parallel. But
  • nothing forces all variables used in given iteration to have same home—communication needed—and
  • arbitrary control flow within iteration. Cannot predict before execution what accesses actually happen.

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