void TraceMap(ZZ_pEX& w, const ZZ_pEX& a, long d, const ZZ_pEXModulus& F,
const ZZ_pEX& b)
{
if (d < 0) LogicError("TraceMap: bad args");
ZZ_pEX y, z, t;
z = b;
y = a;
clear(w);
while (d) {
if (d == 1) {
if (IsZero(w))
w = y;
else {
CompMod(w, w, z, F);
add(w, w, y);
}
}
else if ((d & 1) == 0) {
Comp2Mod(z, t, z, y, z, F);
add(y, t, y);
}
else if (IsZero(w)) {
w = y;
Comp2Mod(z, t, z, y, z, F);
add(y, t, y);
}
else {
Comp3Mod(z, t, w, z, y, w, z, F);
add(w, w, y);
add(y, t, y);
}
d = d >> 1;
}
}
void TraceMap(GF2X& w, const GF2X& a, long d, const GF2XModulus& F,
const GF2X& b)
{
if (d < 0) throw helib::InvalidArgument("TraceMap: d is negative");
GF2X y, z, t;
z = b;
y = a;
clear(w);
while (d) {
if (d == 1) {
if (IsZero(w))
w = y;
else {
CompMod(w, w, z, F);
add(w, w, y);
}
}
else if ((d & 1) == 0) {
Comp2Mod(z, t, z, y, z, F);
add(y, t, y);
}
else if (IsZero(w)) {
w = y;
Comp2Mod(z, t, z, y, z, F);
add(y, t, y);
}
else {
Comp3Mod(z, t, w, z, y, w, z, F);
add(w, w, y);
add(y, t, y);
}
d = d >> 1;
}
}
void TandemPowerCompose(ZZ_pEX& y1, ZZ_pEX& y2, const ZZ_pEX& h,
long q1, long q2, const ZZ_pEXModulus& F)
{
ZZ_pEX z(INIT_SIZE, F.n);
long sw;
z = h;
SetX(y1);
SetX(y2);
while (q1 || q2) {
sw = 0;
if (q1 > 1 || q2 > 1) sw = 4;
if (q1 & 1) {
if (IsX(y1))
y1 = z;
else
sw = sw | 2;
}
if (q2 & 1) {
if (IsX(y2))
y2 = z;
else
sw = sw | 1;
}
switch (sw) {
case 0:
break;
case 1:
CompMod(y2, y2, z, F);
break;
case 2:
CompMod(y1, y1, z, F);
break;
case 3:
Comp2Mod(y1, y2, y1, y2, z, F);
break;
case 4:
CompMod(z, z, z, F);
break;
case 5:
Comp2Mod(z, y2, z, y2, z, F);
break;
case 6:
Comp2Mod(z, y1, z, y1, z, F);
break;
case 7:
Comp3Mod(z, y1, y2, z, y1, y2, z, F);
break;
}
q1 = q1 >> 1;
q2 = q2 >> 1;
}
}
