anchor.diff:      Implicit None
       
       integer, parameter ::  dp = kind(0.d0)
  -    integer, parameter :: i64 = selected_int_kind(18) ! At least 64-bit integer
  +    integer, parameter :: i64 = selected_int_kind(18) 
       
       real(dp) :: sysclock2ms
       integer :: k
  
positive.code:         d=0.d0 !necessary for DGEMM
          
          call system_clock(tic)
          !call dgemm('N','N',N,N,N,1.d0,A,N,B,N,1.d0,d,N) !ifort 14 10% faster than gfortran 5
          e = matmul(A,B) !4-5 times slower with ifort 14 than gfortran 5!
          call system_clock(toc)
          
          if (toc-tic<tmin) tmin=toc-tic
  
negative.code:     
      real(dp) :: d(N,N),e(N,N)
  
      call init_random_seed()
  
  ! https://github.com/JuliaLang/julia/blob/master/test/perf/micro/perf.f90
  
  