C++ (Cpp) mp_expo_1 Examples

Example #1

File: stage1_roots.c Project: coolpraku/msieve

/*------------------------------------------------------------------------*/
static uint32
lift_root_32(uint32 n, uint32 r, uint32 old_power, 
		uint32 p, uint32 d)
{
	uint32 q;
	uint32 p2 = old_power * p;
	uint64 rsave = r;

	q = mp_modsub_1(n % p2, mp_expo_1(r, d, p2), p2) / old_power;
	r = mp_modmul_1(d, mp_expo_1(r % p, d - 1, p), p);
	r = mp_modmul_1(q, mp_modinv_1(r, p), p);
	return rsave + old_power * r;
}

Example #2

File: stage1_roots.c Project: CplusHua/yafu-setup-package

/*------------------------------------------------------------------------*/
static uint32
lift_root_32(uint32 n, uint32 r, uint32 old_power, 
		uint32 p, uint32 d)
{
	/* given r, a d_th root of n mod old_power, compute
	   the corresponding root mod (old_power*p) via Hensel lifting */

	uint32 q;
	uint32 p2 = old_power * p;
	uint64 rsave = r;

	q = mp_modsub_1(n % p2, mp_expo_1(r, d, p2), p2) / old_power;
	r = mp_modmul_1(d, mp_expo_1(r % p, d - 1, p), p);
	r = mp_modmul_1(q, mp_modinv_1(r, p), p);
	return rsave + old_power * r;
}

Example #3

File: makefb.c Project: pstach/gls

static inline u_int32_t mp_modsqrt_1(u_int32_t a, u_int32_t p)
{

	u_int32_t a0 = a;

	if((p & 7) == 3 || (p & 7) == 7)
	{
		return mp_expo_1(a0, (p+1)/4, p);
	}
	else if((p & 7) == 5)
	{
		u_int32_t x, y;

		if(a0 >= p)
		a0 = a0 % p;
		x = mp_expo_1(a0, (p+3)/8, p);

		if(mp_modmul_1(x, x, p) == a0)
			return x;

		y = mp_expo_1(2, (p-1)/4, p);

		return mp_modmul_1(x, y, p);
	}
	else
	{
		u_int32_t d0, d1, a1, s, t, m;
		u_int32_t i;

		if(a0 == 1)
			return 1;

		for(d0 = 2; d0 < p; d0++)
		{
			if(mp_legendre_1(d0, p) != -1)
				continue;

			t = p - 1;
			s = 0;
			while(!(t & 1))
			{
				s++;
				t = t / 2;
			}

			a1 = mp_expo_1(a0, t, p);
			d1 = mp_expo_1(d0, t, p);

			for(i = 0, m = 0; i < s; i++)
			{
				u_int32_t ad;

				ad = mp_expo_1(d1, m, p);
				ad = mp_modmul_1(ad, a1, p);
				ad = mp_expo_1(ad, (u_int32_t)(1) << (s-1-i), p);
				if(ad == (p - 1))
					m += (1 << i);
			}

			a1 = mp_expo_1(a0, (t+1)/2, p);
			d1 = mp_expo_1(d1, m/2, p);
			return mp_modmul_1(a1, d1, p);
		}
	}

	printf("modsqrt_1 failed\n");
	exit(-1);
	return 0;
}