моя программа на c работает медленно (сейчас это около 40 секунд без распараллеливания).Я попытался использовать openmp, что значительно сократило время, но я ищу простые и естественные способы заставить мой код работать быстрее, чем использование параллельных циклов for.Базовая структура кода состоит в том, что некоторые аргументы командной строки принимаются в качестве входных данных, а затем сохраняются в качестве переменных.Затем он рекурсивно вычисляет переменную с именем Rplus1 с использованием библиотеки math.h и complex.h.Проблема кода и того, где он занимает большую часть своего времени, находится внизу, где есть вложенные циклы.Моя цель - запустить весь код менее чем за 5 секунд, но на данный момент он выполняется примерно за 40 секунд без использования параллельных циклов for.Пожалуйста, помогите!
#include "time.h"
#include "stdio.h"
#include "stdlib.h"
#include "complex.h"
#include "math.h"
#include "string.h"
#include "unistd.h"
#include "omp.h"
#define PI 3.14159265
int main (int argc, char *argv[]){
if(argc >= 8){
double start1 = omp_get_wtime();
// command line arguments are aligned in the following order: [theta] [number of layers in superlattice] [material_1] [lat const_1] [number of unit cells_1] [material_2] [lat const_2] [number of unit cells_2] .... [material_N] [lat const_N] [number of unit cells_N] [Log/Linear] [number of repeating superlattice layers] [yes/no]
int N;
sscanf(argv[2],"%d",&N); // Number of layers in superlattice specified by second input argument
if(strcmp(argv[argc-1],"yes") == 0) //If the substrate is included then add one more layer to the N variable
{
N = N+1;
}
int total;
sscanf(argv[argc-2],"%d",&total); // Number of repeating superlattice layers specified by second to last argument
double layers[N][6], horizangle[1001], vertangle[1001];
double complex (*F_hkl)[1001][1001] = malloc(N*1001*1001*sizeof(complex double)), (*F_0)[1001][1001] = malloc(N*1001*1001*sizeof(complex double)), (*g)[1001][1001] = malloc(N*1001*1001*sizeof(complex double)), (*g_0)[1001][1001] = malloc(N*1001*1001*sizeof(complex double)),SF_table[10];// this array will hold the unit cell structure factors for all of the materials selected for each wavevector in the beam spectrum
double real, real2, lam, c_light = 299792458, h_pl = 4.135667516e-15,E = 10e3, r_0 = 2.818e-15, Lccd = 1.013;// just a few variables to hold values through calculations and constants, speed of light, plancks const, photon energy, and detector distance from sample
double angle;
double complex z;// just a variable to hold complex numbers throughout calculations
int i,j,m,n,t; // integers to index through arrays
lam = (h_pl*c_light)/E;
sscanf(argv[1],"%lf",&angle); //first argument is the angle of incidence, read it
angle = angle*(PI/180.0);
angle2 = -angle;
double (*table)[10] = malloc(10*9*sizeof(double)); // this array holds all the coefficients to calculate the atomic scattering factor below
double (*table2)[10] = malloc(10*2*sizeof(double));
FILE*datfile1 = fopen("/home/vhosts/xraydev.engr.wisc.edu/data/coef_table.bin","rb"); // read the binary file containg all the coefficients
fread(table,sizeof(double),90,datfile1);
fclose(datfile1);
FILE*datfile2 = fopen("/home/vhosts/xraydev.engr.wisc.edu/data/dispersioncs.bin","rb");
fread(table2,sizeof(double),20,datfile2);
fclose(datfile2);
// Calculate scattering factors for all elements
double a,b;
double k_z = (sin(angle)/lam)*1e-10; // incorporate angular dependence of SF but neglect 0.24 degree divergence because of approximation
for(i = 0;i<10;i++) // for each element...
{
SF_table[i] = 0;
for(j = 0;j<4;j++) // summation
{
a = table[2*j][i];
b = table[2*j+1][i];
SF_table[i] = SF_table[i] + a * exp(-b*k_z*k_z);
}
SF_table[i] = SF_table[i] + table[8][i] + table2[0][i] + table2[1][i]*I;
}
free(table);
double mm = 4.0, (*phi)[1001][1001] = malloc(N*1001*1001*sizeof(double));
for(i = 1; i < N+1; i++) // for each layer of material...
{
sscanf(argv[i*3+1],"%lf",&layers[i-1][1]); // get out of plane lattice constant
sscanf(argv[i*3+2],"%lf",&layers[i-1][2]); // get the number of unit cells in the layer
layers[i-1][1] = layers[i-1][1]*1e-10; // convert lat const input to meters
// Define reciprocal space positions at the incident angle h, k, l
layers[i-1][3] = 0; // h
layers[i-1][4] = 0; // k
double l; // l calculated for each wavevector in the spectrum because l changes with angle of incidence
for (m = 0; m < 1001; m++)
{
for (n = 0; n <1001; n++)
{
l = 4;
phi[i-1][m][n] = 2*PI*layers[i-1][1]*sin(angle)/lam; // Caculate phi for each layer
if(strcmp(argv[i*3],"GaAs") == 0)
{
F_hkl[i-1][m][n] = (2+2*cexp(I*PI*l))*(SF_table[2]+SF_table[3]*cexp(I*PI*l/2));
F_0[i-1][m][n] = 0.5*8.0*(31 + table2[0][2] + table2[1][2]*I) + 0.5*8.0*(33 + table2[0][3] + table2[1][3]*I);
g[i-1][m][n] = 2*r_0*F_hkl[i-1][m][n]/mm/layers[i-1][1]*cos(2*angle[m][n]);
g_0[i-1][m][n] = 2*r_0*F_0[i-1][m][n]/mm/layers[i-1][1];
}
if(strcmp(argv[i*3],"AlGaAs") == 0)
{
F_hkl[i-1][m][n] = (2+2*cexp(I*PI*l))*((0.76*SF_table[2]+ 0.24*SF_table[4])+SF_table[3]*cexp(I*PI*l/2));
F_0[i-1][m][n] = 0.24*4.0*(13 + table2[0][4] + table2[1][4]*I) + 0.76*4.0*(31 + table2[0][2] + table2[1][2]*I) + 4.0*(33 + table2[0][3] + table2[1][3]*I);
g[i-1][m][n] = 2*r_0*F_hkl[i-1][m][n]/mm/layers[i-1][1]*cos(2*angle[m][n]);
g_0[i-1][m][n] = 2*r_0*F_0[i-1][m][n]/mm/layers[i-1][1];
}
}
}
}
double complex (*Rplus1)[1001] = malloc(1001*1001*sizeof(double complex));
for (m = 0; m < 1001; m++)
{
for (n = 0; n <1001; n++)
{
Rplus1[m][n] = 0.0;
}
}
double stop1 = omp_get_wtime();
for(i=1;i<N;i++) // For each layer of the film
{
for(j=0;j<layers[i][2];j++) // For each unit cell
{
for (m = 0; m < 1001; m++) // For each row of the diffraction pattern
{
for (n = 0; n <1001; n++) // For each column of the diffraction pattern
{
Rplus1[m][n] = -I*g[i][m][n] + ((1-I*g_0[i][m][n])*(1-I*g_0[i][m][n]))/(I*g[i][m][n] + (cos(-2*phi[i][m][n])+I*sin(-2*phi[i][m][n]))/Rplus1[m][n]);
}
}
}
}
double stop2 = omp_get_wtime();
double elapsed1 = (double)(stop1 - start1);// Second user defined function to use Durbin and Follis recursive formula
double elapsed2 = (double)(stop2 - start1);// Second user defined function to use Durbin and Follis recursive formula
printf("main() through before diffraction function took %f seconds to run\n\n",elapsed1);
printf("main() through after diffraction function took %f seconds to run\n\n",elapsed2);
}
}