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1 C******************************************************************************
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2 C FILE: omp_workshare1.f
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3 C DESCRIPTION:
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4 C OpenMP Example - Loop Work-sharing - Fortran Version
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5 C In this example, the iterations of a loop are scheduled dynamically
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6 C across the team of threads. A thread will perform CHUNK iterations
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7 C at a time before being scheduled for the next CHUNK of work.
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8 C AUTHOR: Blaise Barney 5/99
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9 C LAST REVISED: 01/09/04
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10 C******************************************************************************
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11
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12 PROGRAM WORKSHARE1
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13
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14 INTEGER NTHREADS, TID, OMP_GET_NUM_THREADS,
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15 + OMP_GET_THREAD_NUM, N, CHUNKSIZE, CHUNK, I
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16 PARAMETER (N=100)
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17 PARAMETER (CHUNKSIZE=10)
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18 REAL A(N), B(N), C(N)
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19
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20 ! Some initializations
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21 DO I = 1, N
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22 A(I) = I * 1.0
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23 B(I) = A(I)
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24 ENDDO
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25 CHUNK = CHUNKSIZE
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26
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27 !$OMP PARALLEL SHARED(A,B,C,NTHREADS,CHUNK) PRIVATE(I,TID)
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28
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29 TID = OMP_GET_THREAD_NUM()
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30 IF (TID .EQ. 0) THEN
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31 NTHREADS = OMP_GET_NUM_THREADS()
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32 PRINT *, 'Number of threads =', NTHREADS
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33 END IF
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34 PRINT *, 'Thread',TID,' starting...'
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35
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36 !$OMP DO SCHEDULE(DYNAMIC,CHUNK)
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37 DO I = 1, N
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38 C(I) = A(I) + B(I)
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39 WRITE(*,100) TID,I,C(I)
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40 100 FORMAT(' Thread',I2,': C(',I3,')=',F8.2)
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41 ENDDO
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42 !$OMP END DO NOWAIT
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43
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44 PRINT *, 'Thread',TID,' done.'
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45
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46 !$OMP END PARALLEL
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47
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48 END
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