DoubleCRT& DoubleCRT::Op(const DoubleCRT &other, Fun fun,
bool matchIndexSets)
{
if (dryRun) return *this;
if (&context != &other.context)
Error("DoubleCRT::Op: incompatible objects");
// Match the index sets, if needed
if (matchIndexSets && !(map.getIndexSet() >= other.map.getIndexSet()))
addPrimes(other.map.getIndexSet() / map.getIndexSet()); // This is expensive
// If you need to mod-up the other, do it on a temporary scratch copy
DoubleCRT tmp(context, IndexSet());
const IndexMap<vec_long>* other_map = &other.map;
if (!(map.getIndexSet() <= other.map.getIndexSet())){ // Even more expensive
tmp = other;
tmp.addPrimes(map.getIndexSet() / other.map.getIndexSet());
other_map = &tmp.map;
}
const IndexSet& s = map.getIndexSet();
long phim = context.zMStar.getPhiM();
// add/sub/mul the data, element by element, modulo the respective primes
for (long i = s.first(); i <= s.last(); i = s.next(i)) {
long pi = context.ithPrime(i);
vec_long& row = map[i];
const vec_long& other_row = (*other_map)[i];
for (long j = 0; j < phim; j++)
row[j] = fun.apply(row[j], other_row[j], pi);
}
return *this;
}
// Generic operators, Fnc is either AddMod or SubMod
// This should have been a template, but gcc refuses to cooperate
SingleCRT& SingleCRT::Op(const SingleCRT &other,
void (*Fnc)(ZZ&, const ZZ&, const ZZ&, const ZZ&),
bool matchIndexSets)
{
if (&context != &other.context)
Error("SingleCRT::Op: incomopatible objects");
// Match the index sets, if needed
if (matchIndexSets && !(map.getIndexSet() >= other.map.getIndexSet()))
addPrimes(other.map.getIndexSet() / map.getIndexSet()); // This is expensive
// INVARIANT: map.getIndexSet() >= other.map.getIndexSet())
SingleCRT tmp(context); // a rare case where you want an empty SingleCRT object
const IndexMap<ZZX>* other_map = &other.map;
if (map.getIndexSet() > other.map.getIndexSet()) { // Even more expensive
tmp = other;
tmp.addPrimes(map.getIndexSet() / other.map.getIndexSet());
other_map = &tmp.map;
}
const IndexSet& s = map.getIndexSet();
// add/sub polynomial, modulo the respective primes
for (long i = s.first(); i <= s.last(); i = s.next(i)) {
ZZ pi = to_ZZ(context.ithPrime(i));
vec_ZZ& vp1 = map[i].rep;
const vec_ZZ& vp2 = (*other_map)[i].rep;
long len1 = vp1.length();
long len2 = vp2.length();
long maxlen = max(len1, len2);
vp1.SetLength(maxlen);
for (long j=len1; j < maxlen; j++) clear(vp1[j]);
for (long j=0; j<len2; j++)
Fnc(vp1[j], vp1[j], vp2[j], pi);
map[i].normalize();
}
return *this;
}
