!!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!! !!! Copyright (c) 2017-20, Lawrence Livermore National Security, LLC !!! and DataRaceBench project contributors. See the DataRaceBench/COPYRIGHT file for details. !!! !!! SPDX-License-Identifier: (BSD-3-Clause) !!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!! !The outmost loop is be parallelized. !But the inner level loop has out of bound access for b[i][j] when i equals to 1. !This will case memory access of a previous column's last element. ! !For example, an array of 4x4: ! j=1 2 3 4 ! i=1 x x x x ! 2 x x x x ! 3 x x x x ! 4 x x x x ! outer loop: j=3, ! inner loop: i=1 ! array element accessed b[i-1][j] becomes b[0][3], which in turn is b[4][2] ! due to linearized column-major storage of the 2-D array. ! This causes loop-carried data dependence between j=2 and j=3. ! ! !Data race pair: b[i][j]@67 vs. b[i-1][j]@67 program DRB015_outofbounds_var_yes use omp_lib implicit none integer :: i, j, n, m, len, argCount, allocStatus, rdErr, ix character(len=80), dimension(:), allocatable :: args real, dimension (:,:), allocatable :: b len = 100 argCount = command_argument_count() if (argCount == 0) then write (*,'(a)') "No command line arguments provided." end if allocate(args(argCount), stat=allocStatus) if (allocStatus > 0) then write (*,'(a)') "Allocation error, program terminated." stop end if do ix = 1, argCount call get_command_argument(ix,args(ix)) end do if (argCount >= 1) then read (args(1), '(i10)', iostat=rdErr) len if (rdErr /= 0 ) then write (*,'(a)') "Error, invalid integer value." end if end if n = len m = len allocate (b(n,m)) !$omp parallel do private(i) do j = 2, n do i = 1, m b(i,j) = b(i-1,j) end do end do !$omp end parallel do print*,"b(50,50)=",b(50,50) deallocate(args,b) end program