/* Add arrays of contiguous data */

typedef struct {double real; double imag;} cdouble;

typedef struct {float real; float imag;} cfloat;

void zadd(cdouble *a, cdouble *b, cdouble *c, long n)

{

while (n--) {

c->real = a->real + b->real;

c->imag = a->imag + b->imag;

a++; b++; c++;

}

}

//with similar code for cadd, dadd, and sadd that handles complex float, double, and float data-types, respectively:

void cadd(cfloat *a, cfloat *b, cfloat *c, long n)

{

while (n--) {

c->real = a->real + b->real;

c->imag = a->imag + b->imag;

a++; b++; c++;

}

}

void dadd(double *a, double *b, double *c, long n)

{

while (n--) {

*c++ = *a++ + *b++;

}

}

void sadd(float *a, float *b, float *c, long n)

{

while (n--) {

*c++ = *a++ + *b++;

}

}

//The code.c file also contains the function dfilter2d:

/* Assumes b is contiguous and

a has strides that are multiples of sizeof(double)

*/

void

dfilter2d(double *a, double *b, int *astrides, int *dims)

{

int i, j, M, N, S0, S1;

int r, c, rm1, rp1, cp1, cm1;

M = dims[0]; N = dims[1];

S0 = astrides[0]/sizeof(double);

S1=astrides[1]/sizeof(double);

for (i=1; i<M-1; i++) {

r = i*S0; rp1 = r+S0; rm1 = r-S0;

for (j=1; j<N-1; j++) {

c = j*S1; cp1 = j+S1; cm1 = j-S1;

b[i*N+j] = a[r+c] + \

(a[rp1+c] + a[rm1+c] + \

a[r+cp1] + a[r+cm1])*0.5 + \

(a[rp1+cp1] + a[rp1+cm1] + \

a[rm1+cp1] + a[rm1+cp1])*0.25;

}

}

}