/* gets no. of points from the user, initialize the points and roots of unity lookup table
* and lets fft go. finally bit-reverses the results and outputs them into a file.
* n should be a power of 2.
*/
int main(int argc, char *argv[])
{
int n;
double *A_re, *A_im, *W_re, *W_im;
long long start, end;
struct timespec ts;
if (argc <= 2)
{
fprintf(stderr, "Usage: ./fft n outfile\n");
exit(-1);
}
n = atoi(argv[1]);
A_re = (double*)_mm_malloc(sizeof(double)*n, 32);
A_im = (double*)_mm_malloc(sizeof(double)*n, 32);
W_re = (double*)_mm_malloc(sizeof(double)*n/2, 32);
W_im = (double*)_mm_malloc(sizeof(double)*n/2, 32);
assert(A_re != NULL && A_im != NULL && W_re != NULL && W_im != NULL);
init_array(n, A_re, A_im);
compute_W(n, W_re, W_im);
clock_gettime(CLOCK_MONOTONIC, &ts);
start = ts.tv_sec * 1000000ULL + ts.tv_nsec / 1000;
fft(n, A_re, A_im, W_re, W_im);
clock_gettime(CLOCK_MONOTONIC, &ts);
end = ts.tv_sec * 1000000ULL + ts.tv_nsec / 1000;
permute_bitrev(n, A_re, A_im);
// output_array(n, A_re, A_im, argv[2]);
printf ("The total CPU time of FFT is: %lld microseconds.\n", end - start);
printf ("The number of errors is %lld \n.", errors);
_mm_free(A_re);
_mm_free(A_im);
_mm_free(W_re);
_mm_free(W_im);
}
void begin()
{
int i;
float *A, *W_re, *W_im;
A = (float*)malloc(sizeof(float)*2*n);
W_re = (float*)malloc(sizeof(float)*n/2);
W_im = (float*)malloc(sizeof(float)*n/2);
/* assert(A_re != NULL && A_im != NULL && W_re != NULL && W_im != NULL); */
compute_W(W_re, W_im);
while (numiters == -1 || numiters-- > 0) {
init_array(A);
fft(A, W_re, W_im);
#ifdef FFT2
permute_bitrev(A);
#endif
output_array(A);
}
free(A);
free(W_re);
free(W_im);
}
