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A Possible Solution

Problem occurs when descriptive mappings are used to reduce communications. Consider,

    REAL, DIMENSION(100,100) :: A, B
!HPF$ PROCESSORS, DIMENSION(10,10) :: P
!HPF$ DISTRIBUTE (BLOCK,BLOCK) :: A, B
    INTERFACE
     SUBROUTINE KerXubbie(x,y)
      REAL, DIMENSION(:) :: x, y
      !HPF$ PROCESSORS,DIMENSION(10) :: P ! non-HPF
      !HPF$ ALIGN y WITH *x
      !HPF$ DISTRIBUTE *(BLOCK) ONTO *P :: x
     END SUBROUTINE KerXubbie
    END INTERFACE
     ...
    CALL KerXubbie(A(i,:),b(i,:))

Asserts that x and y are co-mapped and distributed blockwise over 10 processor subset! Not portable but semantics work!

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Next: The Next Problem Up: Procedures Previous: Processors Problem

©University of Liverpool, 1997
Wed May 28 23:37:18 BST 1997
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