| 1 | !!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!!
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| 2 | !!! Copyright (c) 2017-20, Lawrence Livermore National Security, LLC
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| 3 | !!! and DataRaceBench project contributors. See the DataRaceBench/COPYRIGHT file for details.
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| 4 | !!!
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| 5 | !!! SPDX-License-Identifier: (BSD-3-Clause)
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| 6 | !!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!!
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| 7 |
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| 8 | !Two pointers have distance of 12 (p1 - p2 = 12).
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| 9 | !They are used as base addresses for indirect array accesses using an index set (another array).
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| 10 | !
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| 11 | !An index set has two indices with distance of 12 :
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| 12 | !indexSet[3]- indexSet[0] = 533 - 521 = 12
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| 13 | !So there is loop carried dependence for N=0 and N=3.
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| 14 | !
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| 15 | !We use the default loop scheduling (static even) in OpenMP.
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| 16 | !It is possible that two dependent iterations will be scheduled
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| 17 | !within a same chunk to a same thread. So there is no runtime data races.
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| 18 | !
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| 19 | !N is 180, two iteraions with N=0 and N= 3 have loop carried dependences.
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| 20 | !For static even scheduling, we must have at least 60 threads (180/60=3 iterations)
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| 21 | !so iteration 0 and 3 will be scheduled to two different threads.
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| 22 | !Data race pair: xa1[idx]@81 vs. xa2[idx]@82
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| 23 |
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| 24 |
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| 25 |
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| 26 | module DRB007
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| 27 | implicit none
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| 28 |
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| 29 | integer, dimension(180) :: indexSet
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| 30 | integer :: n
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| 31 |
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| 32 | end module
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| 33 |
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| 34 |
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| 35 | program DRB007_indirectaccess3_orig_yes
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| 36 | use omp_lib
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| 37 | use DRB007
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| 38 | implicit none
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| 39 |
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| 40 | integer :: i, idx1, idx2
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| 41 | integer, parameter :: dp = kind(1.0d0)
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| 42 | real(dp), dimension(:), pointer :: xa1=>NULL(), xa2=>NULL()
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| 43 | real(dp), dimension(2025), target :: base
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| 44 |
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| 45 | allocate (xa1(2025))
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| 46 | allocate (xa2(2025))
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| 47 |
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| 48 | xa1 => base(1:2025)
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| 49 | xa2 => base(1:2025)
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| 50 |
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| 51 | n=180
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| 52 |
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| 53 | indexSet = (/ 521, 523, 525, 533, 529, 531, 547, 549, &
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| 54 | 551, 553, 555, 557, 573, 575, 577, 579, 581, 583, 599, &
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| 55 | 601, 603, 605, 607, 609, 625, 627, 629, 631, 633, 635, &
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| 56 | 651, 653, 655, 657, 659, 661, 859, 861, 863, 865, 867, &
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| 57 | 869, 885, 887, 889, 891, 893, 895, 911, 913, 915, 917, &
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| 58 | 919, 921, 937, 939, 941, 943, 945, 947, 963, 965, 967, &
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| 59 | 969, 971, 973, 989, 991, 993, 995, 997, 999, 1197, 1199, &
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| 60 | 1201, 1203, 1205, 1207, 1223, 1225, 1227, 1229, 1231, &
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| 61 | 1233, 1249, 1251, 1253, 1255, 1257, 1259, 1275, 1277, &
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| 62 | 1279, 1281, 1283, 1285, 1301, 1303, 1305, 1307, 1309, &
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| 63 | 1311, 1327, 1329, 1331, 1333, 1335, 1337, 1535, 1537, &
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| 64 | 1539, 1541, 1543, 1545, 1561, 1563, 1565, 1567, 1569, &
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| 65 | 1571, 1587, 1589, 1591, 1593, 1595, 1597, 1613, 1615, &
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| 66 | 1617, 1619, 1621, 1623, 1639, 1641, 1643, 1645, 1647, &
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| 67 | 1649, 1665, 1667, 1669, 1671, 1673, 1675, 1873, 1875, &
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| 68 | 1877, 1879, 1881, 1883, 1899, 1901, 1903, 1905, 1907, &
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| 69 | 1909, 1925, 1927, 1929, 1931, 1933, 1935, 1951, 1953, &
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| 70 | 1955, 1957, 1959, 1961, 1977, 1979, 1981, 1983, 1985, &
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| 71 | 1987, 2003, 2005, 2007, 2009, 2011, 2013 /)
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| 72 |
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| 73 | do i = 521, 2025
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| 74 | base(i) = 0.5*i
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| 75 | end do
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| 76 |
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| 77 | !$omp parallel do
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| 78 | do i = 1, n
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| 79 | idx1 = indexSet(i)
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| 80 | idx2 = indexSet(i)+12
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| 81 | base(idx1) = base(idx1)+1.0
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| 82 | base(idx2) = base(idx2)+3.0
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| 83 | end do
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| 84 | !$omp end parallel do
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| 85 |
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| 86 | print*,'xa1(999) =',base(999),' xa2(1285) =',base(1285)
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| 87 |
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| 88 | nullify(xa1,xa2)
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| 89 | end program
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