void replicate0(const EncryptedArray& ea, Ctxt& ctxt, long pos)
{
long dim = ea.dimension();
for (long d = 0; d < dim; d++) {
if (!ea.nativeDimension(d)) {
long shamt = -ea.coordinate(d, pos);
ea.rotate1D(ctxt, d, shamt, true); // "don't care"
}
Ctxt ctxt_orig = ctxt;
long sz = ea.sizeOfDimension(d);
long k = NumBits(sz);
long e = 1;
// now process bits k-2 down to 0
for (long j = k-2; j >= 0; j--) {
// e -> 2*e
Ctxt tmp = ctxt;
ea.rotate1D(tmp, d, e, true); // "don't care"
ctxt += tmp;
e = 2*e;
long b = bit(sz, j); // bit j of sz
// e -> e+b
if (b) {
ea.rotate1D(ctxt, d, 1, true); // "don't care"
ctxt += ctxt_orig;
e++;
}
}
}
}
static void replicateOneBlock(const EncryptedArray& ea, Ctxt& ctxt,
long pos, long blockSize, long d)
{
long dSize = ea.sizeOfDimension(d);
// Move this block to position 0. We can skip this step in
// "good dimensions" of size divisible by the block size
if (pos != 0 && (!ea.nativeDimension(d) || dSize % blockSize != 0) ) {
ea.rotate1D(ctxt, d, -pos*blockSize, true);
}
long sz = dSize/blockSize; // how many blocks fit in this dimension
if (sz == 1) return; // nothing to do, only one block in this dimension
// do the actual replication using "shift and add"
long k = NumBits(sz);
long e = 1;
Ctxt ctxt_orig = ctxt;
// now process bits k-2 down to 0
for (long j = k-2; j >= 0; j--) {
// e -> 2*e
Ctxt tmp = ctxt;
ea.rotate1D(tmp, d, e*blockSize, /*don't-care-flag=*/true);
ctxt += tmp;
e = 2*e;
long b = bit(sz, j); // bit j of sz
// e -> e+b
if (b) {
ea.rotate1D(ctxt, d, 1*blockSize, /*don't-care-flag=*/true);
ctxt += ctxt_orig;
e++;
}
}
}
