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Loop Distribution

Allow code in outer loop to be vectorized.

DO J = 1, N
  A(J,J) = X(J)*3
  DO I = 1, N
    B(I,J) = A(I,J)*C(I,J)
  ENDDO
ENDDO

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V

DO J = 1, N
  A(J,J) = X(J)*3
ENDDO

DO J = 1, N
  DO I = 1, N
    B(I,J) = A(I,J)*C(I,J)
  ENDDO
ENDDO

Both loops can be vectorized!