int convolve_real(const float x[], const float y[], float out[], size_t n) {
float *ximag, *yimag, *zimag;
int status = 0;
ximag = calloc(n, sizeof(float));
yimag = calloc(n, sizeof(float));
zimag = calloc(n, sizeof(float));
if (ximag == NULL || yimag == NULL || zimag == NULL)
goto cleanup;
status = convolve_complex(x, ximag, y, yimag, out, zimag, n);
cleanup:
free(zimag);
free(yimag);
free(ximag);
return status;
}
int convolve_real(const double x[], const double y[], double out[], size_t n) {
double *ximag, *yimag, *zimag;
int status = 0;
ximag = calloc(n, sizeof(double));
yimag = calloc(n, sizeof(double));
zimag = calloc(n, sizeof(double));
if (ximag == NULL || yimag == NULL || zimag == NULL)
goto cleanup;
status = convolve_complex(x, ximag, y, yimag, out, zimag, n);
cleanup:
free(zimag);
free(yimag);
free(ximag);
return status;
}
int transform_bluestein(float real[], float imag[], size_t n) {
// Variables
int status = 0;
//float *cos_table, *sin_table;
float *areal, *aimag;
float *breal, *bimag;
float *creal, *cimag;
size_t m;
size_t size_n, size_m;
size_t i;
// Find a power-of-2 convolution length m such that m >= n * 2 + 1
{
size_t target;
if (n > (N_MAX - 1) / 2)
return 0;
target = n * 2 + 1;
for (m = 1; m < target; m *= 2) {
if (N_MAX / 2 < m)
return 0;
}
}
// Allocate memory
if (N_MAX / sizeof(float) < n || N_MAX / sizeof(float) < m)
return 0;
size_n = n * sizeof(float);
size_m = m * sizeof(float);
//cos_table = malloc(size_n);
//sin_table = malloc(size_n);
areal = calloc(m, sizeof(float));
aimag = calloc(m, sizeof(float));
breal = calloc(m, sizeof(float));
bimag = calloc(m, sizeof(float));
creal = malloc(size_m);
cimag = malloc(size_m);
if (areal == NULL || aimag == NULL
|| breal == NULL || bimag == NULL
|| creal == NULL || cimag == NULL)
goto cleanup;
// Trignometric tables
/*for (i = 0; i < n; i++) {
//float temp = M_PI * (size_t)((unsigned long long)i * i % ((unsigned long long)n * 2)) / n;
// Less accurate version if long long is unavailable: float temp = M_PI * i * i / n;
cos_table[i] = cos(temp);
sin_table[i] = sin(temp);
}*/
// Temporary vectors and preprocessing
for (i = 0; i < n; i++) {
areal[i] = sum_acc(mul_acc(real[i], cos_mod(i,n)), mul_acc(imag[i], sin_mod(i,n)));
aimag[i] = sum_acc(mul_acc(-real[i], sin_mod(i,n)), mul_acc(imag[i], cos_mod(i,n)));
}
breal[0] = cos_mod(0,n);
bimag[0] = sin_mod(0,n);
for (i = 1; i < n; i++) {
breal[i] = breal[m - i] = cos_mod(i,n);
bimag[i] = bimag[m - i] = sin_mod(i,n);
}
// Convolution
if (!convolve_complex(areal, aimag, breal, bimag, creal, cimag, m))
goto cleanup;
// Postprocessing
for (i = 0; i < n; i++) {
real[i] = sum_acc(mul_acc(creal[i], cos_mod(i,n)), mul_acc(cimag[i], sin_mod(i,n)));
imag[i] = sum_acc(mul_acc(-creal[i], sin_mod(i,n)), mul_acc(cimag[i], cos_mod(i,n)));
}
status = 1;
// Deallocation
cleanup:
free(cimag);
free(creal);
free(bimag);
free(breal);
free(aimag);
free(areal);
//free(sin_table);
//free(cos_table);
return status;
}
int transform_bluestein(double real[], double imag[], size_t n) {
// Variables
int status = 0;
double *cos_table, *sin_table;
double *areal, *aimag;
double *breal, *bimag;
double *creal, *cimag;
size_t m;
size_t size_n, size_m;
size_t i;
// Find a power-of-2 convolution length m such that m >= n * 2 + 1
{
size_t target;
if (n > (SIZE_MAX - 1) / 2)
return 0;
target = n * 2 + 1;
for (m = 1; m < target; m *= 2) {
if (SIZE_MAX / 2 < m)
return 0;
}
}
// Allocate memory
if (SIZE_MAX / sizeof(double) < n || SIZE_MAX / sizeof(double) < m)
return 0;
size_n = n * sizeof(double);
size_m = m * sizeof(double);
cos_table = malloc(size_n);
sin_table = malloc(size_n);
areal = calloc(m, sizeof(double));
aimag = calloc(m, sizeof(double));
breal = calloc(m, sizeof(double));
bimag = calloc(m, sizeof(double));
creal = malloc(size_m);
cimag = malloc(size_m);
if (cos_table == NULL || sin_table == NULL
|| areal == NULL || aimag == NULL
|| breal == NULL || bimag == NULL
|| creal == NULL || cimag == NULL)
goto cleanup;
// Trignometric tables
for (i = 0; i < n; i++) {
double temp = M_PI * (size_t)((unsigned long long)i * i % ((unsigned long long)n * 2)) / n;
// Less accurate version if long long is unavailable: double temp = M_PI * i * i / n;
cos_table[i] = cos(temp);
sin_table[i] = sin(temp);
}
// Temporary vectors and preprocessing
for (i = 0; i < n; i++) {
areal[i] = real[i] * cos_table[i] + imag[i] * sin_table[i];
aimag[i] = -real[i] * sin_table[i] + imag[i] * cos_table[i];
}
breal[0] = cos_table[0];
bimag[0] = sin_table[0];
for (i = 1; i < n; i++) {
breal[i] = breal[m - i] = cos_table[i];
bimag[i] = bimag[m - i] = sin_table[i];
}
// Convolution
if (!convolve_complex(areal, aimag, breal, bimag, creal, cimag, m))
goto cleanup;
// Postprocessing
for (i = 0; i < n; i++) {
real[i] = creal[i] * cos_table[i] + cimag[i] * sin_table[i];
imag[i] = -creal[i] * sin_table[i] + cimag[i] * cos_table[i];
}
status = 1;
// Deallocation
cleanup:
free(cimag);
free(creal);
free(bimag);
free(breal);
free(aimag);
free(areal);
free(sin_table);
free(cos_table);
return status;
}
