I wrote a program with Julia, but the performance is disappointing.
The program is constructed with some functions, and global variables are prevented, arrays are well preallocated before used, the fft operation is accelerated by setting FFTW.set_num_threads(Sys.CPU_CORES).
No red words are shown when profiling it with @code_warntype. When I use the @profile macro to find out the bottleneck of the code, I find all the most-time-consuming lines share a common word: cis!
Below are these lines:
for j in eachindex(u) prop_e[j] = cis( -ele * (xplusy[j] * dt/2.0) ) * prop_x[j] # 2209 end ... for j2 in 1:ngrid, j1 in 1:ngrid uo[j1+Δn, j2+Δn] = u[j1, j2] * splitter[j1, j2] * cis(A[i]*xplusy[j1, j2]) ## 2462 end ... for j2 in 1:ngrid2, j1 in 1:ngrid2 uo[j1, j2] *= cis( -dt * (pp[j1] + pp[j2]) ) # 38049 end
the number at the end of each line is the corresponding result of Profile.print() for this line. Note that the total number is 50454.
When I implement the program with Fortran, these lines never much time, but never so much. I wonder if there is anything wrong with my Julia version.