C++ (Cpp) bn_mul_comba Examples

Example #1

File: bn_ext.c Project: zebrafly/pi3

int bn_mult_arrays(bn_st * bn_out, bn_st * bn_array1, bn_st * bn_array2, int size)
{
	for (int i = 0; i < size; ++i)
	{
		switch (MULT_TYPE)
		{
			case 'b':		// Basic
				bn_mul_basic(&bn_out[i], &bn_array1[i], &bn_array2[i]);
				break;
			case 'c':		// Comba
				bn_mul_comba(&bn_out[i], &bn_array1[i], &bn_array2[i]);
				break;
			case 'k':		// Karatsuba
				bn_mul_karat(&bn_out[i], &bn_array1[i], &bn_array2[i]);
				break;
			default:
				error_hdl(-1,"Multiplication type not recognized");
				return 1;
		}
	}
	return 0;
}

Example #2

File: relic_bn_sqr.c Project: lucamelis/relic

/**
 * Computes the square of a multiple precision integer using recursive Karatsuba
 * squaring.
 *
 * @param[out] c			- the result.
 * @param[in] a				- the multiple precision integer to square.
 * @param[in] level			- the number of Karatsuba steps to apply.
 */
static void bn_sqr_karat_imp(bn_t c, const bn_t a, int level) {
	int h;
	bn_t a0, a1, a0a0, a1a1, t;
	const dig_t *tmpa;
	dig_t *t0;

	bn_null(a0);
	bn_null(a1);
	bn_null(a0a0);
	bn_null(a1a1);
	bn_null(t);

	/* Compute half the digits of a or b. */
	h = a->used >> 1;

	TRY {
		/* Allocate the temp variables. */
		bn_new(a0);
		bn_new(a1);
		bn_new(a0a0);
		bn_new(a1a1);
		bn_new(t);

		a0->used = h;
		a1->used = a->used - h;

		tmpa = a->dp;

		/* a = a1 || a0 */
		t0 = a0->dp;
		for (int i = 0; i < h; i++, t0++, tmpa++)
			*t0 = *tmpa;
		t0 = a1->dp;
		for (int i = 0; i < a1->used; i++, t0++, tmpa++)
			*t0 = *tmpa;

		bn_trim(a0);

		if (level <= 1) {
			/* a0a0 = a0 * a0 and a1a1 = a1 * a1 */
#if BN_SQR == BASIC
			bn_sqr_basic(a0a0, a0);
			bn_sqr_basic(a1a1, a1);
#elif BN_SQR == COMBA
			bn_sqr_comba(a0a0, a0);
			bn_sqr_comba(a1a1, a1);
#elif BN_SQR == MULTP
			bn_mul_comba(a0a0, a0, a0);
			bn_mul_comba(a1a1, a1, a1);
#endif
		} else {
			bn_sqr_karat_imp(a0a0, a0, level - 1);
			bn_sqr_karat_imp(a1a1, a1, level - 1);
		}

		/* t = (a1 + a0) */
		bn_add(t, a1, a0);

		if (level <= 1) {
			/* t = (a1 + a0)*(a1 + a0) */
#if BN_SQR == BASIC
			bn_sqr_basic(t, t);
#elif BN_SQR == COMBA
			bn_sqr_comba(t, t);
#elif BN_SQR == MULTP
			bn_mul_comba(t, t, t);
#endif
		} else {
			bn_sqr_karat_imp(t, t, level - 1);
		}

		/* t2 = (a0*a0 + a1*a1) */
		bn_add(a0, a0a0, a1a1);
		/* t = (a1 + a0)*(b1 + b0) - (a0*a0 + a1*a1) */
		bn_sub(t, t, a0);

		/* t = (a1 + a0)*(a1 + a0) - (a0*a0 + a1*a1) << h digits */
		bn_lsh(t, t, h * BN_DIGIT);

		/* t2 = a1 * b1 << 2*h digits */
		bn_lsh(a1a1, a1a1, 2 * h * BN_DIGIT);

		/* t = t + a0*a0 */
		bn_add(t, t, a0a0);
		/* c = t + a1*a1 */
		bn_add(t, t, a1a1);

		t->sign = BN_POS;
		bn_copy(c, t);
	}
	CATCH_ANY {
		THROW(ERR_CAUGHT);
	}
	FINALLY {
		bn_free(a0);
		bn_free(a1);
		bn_free(a0a0);
		bn_free(a1a1);
		bn_free(t);
	}
}