test_power2()
{
//GF2m b(4);
GF2m* b;
for (int i=3;i< 50;i++)
{
b = new GF2m(i);
b->SetPrimitive();
power2(*b,b->BitLength);
// b.Square();
dec(*b);
printf("\nm=%i b = %062s",i, b->Print(FMT_BIN, buf1));
delete b;
}
/*b.SetPrimitive();
power2(b,b.BitLength);
// b.Square();
b--;
printf("\n b = %032s", b.Print(FMT_BIN, buf1));*/
}
void power2(GF2m& a, uint32 b)
{
uint32 j = 0;
uint32 i = 1 << 31;
while ((b & i) == 0)
{
i = i >> 1;
if (i == 0) return;
}
b = b ^ i;
power2(a,b);
j = 0;
while (i != 0)
{
j++;
i = i >> 1;
}
j--;
i = 1;
for (uint32 i1 = 0; i1< j; i1++)
{
i = i*2;
}
j = i;
//j = 2 << j;
for (uint32 j1 = 0; j1 < j; j1++)
{
a.Square();
}
}
void reduce(const Poly2& p,Poly2Mod& rem)
{
int m,d;
GF2m t;
big *G;
term2 *ptr,*pos=NULL;
int n=degree(p);
int degm=degree(Modulus);
if (n-degm < KARAT_BREAK_EVEN)
{
rem=(Poly2Mod)p;
return;
}
G=(big *)mr_alloc(2*(N+2),sizeof(big));
ptr=p.start;
while (ptr!=NULL)
{
G[ptr->n]=getbig(ptr->an);
ptr=ptr->next;
}
karmul2_poly(N,T,GRF,&G[N],W); // W=(G/x^n) * h
for (d=N-1;d<2*N;d++) copy(W[d],Q[d-N+1]);
m=N+1; if(m%2==1) m=N+2; // make sure m is even - pad if necessary
for (d=m;d<2*m;d++) copy(G[d],W[d]);
karmul2_poly_upper(m,T,GF,Q,W);
pos=NULL;
rem.clear();
for (d=N-1;d>=0;d--)
{
add2(W[d],G[d],W[d]);
t=W[d];
if (t.iszero()) continue;
pos=rem.addterm(t,d,pos);
}
mr_free(G);
}
int cmp(const GF2m& a, const uint32 small_number)
{
// return 0 - equal; 1 - non equal
//if (a.BitLength > 32) CRASH("fields size mismatch");
uint32* pn = a.n;
if (a.GetHighInt32() == 0)
{
if (pn[0] == small_number) return 0;
}
return 1;
}
int cmp(const GF2m& a, const GF2m& b)
{
// return 0 - equal; 1 - non equal
if (a.BitLength > b.BitLength) CRASH("fields sizes are not equal");
uint32* pn1 = a.n;
uint32* pn2 = b.n;
for (int32 i=a.GetInt32Length(); i >= 0; i--)
{
if (pn1[i] != pn2[i]) return 1;
}
return 0;
}
void SearchF()
{
GF2m* a;
GF2m* b;
for (int i=3;i< 50;i++)
{
a = new GF2m(i);
b = new GF2m(i);
a->SetOne();
b->SetPrimitive();
a->Inverse();
//dec(*a);
printf("\nm=%i inverse() = %050s",i, a->Print(FMT_BIN, buf1));
power2(*b,b->BitLength);
// b.Square();
dec(*b);
printf("\nm=%i ^2^m-1 = %050s",i, b->Print(FMT_BIN, buf1));
printf("\n");
delete b;
delete a;
}
{
i = 167;
a = new GF2m(i);
b = new GF2m(i);
a->SetOne();
b->SetPrimitive();
a->Inverse();
//dec(*a);
printf("\nm=%i inverse() = %050s",i, a->Print(FMT_BIN, buf1));
power2(*b,b->BitLength);
// b.Square();
dec(*b);
printf("\nm=%i ^2^m-1 = %050s",i, b->Print(FMT_BIN, buf1));
printf("\n");
delete b;
delete a;
}
}
Poly2 operator*(const Poly2& a,const Poly2& b)
{
int i,d,dega,degb,deg;
GF2m t;
Poly2 prod;
term2 *iptr,*pos;
term2 *ptr=b.start;
if (&a==&b)
{ // squaring - only diagonal terms count!
pos=NULL;
while (ptr!=NULL)
{ // diagonal terms
pos=prod.addterm(ptr->an*ptr->an,ptr->n+ptr->n,pos);
ptr=ptr->next;
}
return prod;
}
dega=degree(a);
deg=dega;
degb=degree(b);
if (degb<dega) deg=degb; // deg is smallest
if (deg>=KARAT_BREAK_EVEN)
{ // use fast method
int len,m,inc;
big *A,*B,*C,*T;
deg=dega;
if (dega<degb) deg=degb; // deg is biggest
m=deg; inc=1;
while (m!=0) { m/=2; inc++; }
len=2*(deg+inc);
A=(big *)mr_alloc(deg+1,sizeof(big));
B=(big *)mr_alloc(deg+1,sizeof(big));
C=(big *)mr_alloc(len,sizeof(big));
T=(big *)mr_alloc(len,sizeof(big));
char *memc=(char *)memalloc(len);
char *memt=(char *)memalloc(len);
for (i=0;i<len;i++)
{
C[i]=mirvar_mem(memc,i);
T[i]=mirvar_mem(memt,i);
}
ptr=a.start;
while (ptr!=NULL)
{
A[ptr->n]=getbig(ptr->an);
ptr=ptr->next;
}
ptr=b.start;
while (ptr!=NULL)
{
B[ptr->n]=getbig(ptr->an);
ptr=ptr->next;
}
karmul2_poly(deg+1,T,A,B,C);
pos=NULL;
for (d=dega+degb;d>=0;d--)
{
t=C[d];
if (t.iszero()) continue;
pos=prod.addterm(t,d,pos);
}
memkill(memc,len);
memkill(memt,len);
mr_free(T);
mr_free(C);
mr_free(B);
mr_free(A);
return prod;
}
while (ptr!=NULL)
{
pos=NULL;
iptr=a.start;
while (iptr!=NULL)
{
pos=prod.addterm(ptr->an*iptr->an,ptr->n+iptr->n,pos);
iptr=iptr->next;
}
ptr=ptr->next;
}
return prod;
}
