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/*************************************************
* Simple Multiplication Source File *
* (C) 1999-2005 The Botan Project *
*************************************************/
#include <botan/mp_core.h>
#include <botan/mp_madd.h>
#include <botan/mem_ops.h>
namespace Botan {
/*************************************************
* Two Operand Linear Multiply *
*************************************************/
void bigint_linmul2(word x[], u32bit x_size, word y)
{
word carry = 0;
for(u32bit j = 0; j != x_size; j++)
bigint_madd(x[j], y, carry, 0, x + j, &carry);
x[x_size] = carry;
}
/*************************************************
* Three Operand Linear Multiply *
*************************************************/
void bigint_linmul3(word z[], const word x[], u32bit x_size, word y)
{
word carry = 0;
for(u32bit j = 0; j != x_size; j++)
bigint_madd(x[j], y, carry, 0, z + j, &carry);
z[x_size] = carry;
}
/*************************************************
* Simple O(N^2) Multiplication *
*************************************************/
void bigint_smul(word z[], const word x[], u32bit x_size,
const word y[], u32bit y_size)
{
const u32bit blocks = y_size - (y_size % 8);
clear_mem(z, x_size + y_size);
for(u32bit j = 0; j != x_size; j++)
{
const word x_j = x[j];
word carry = 0;
for(u32bit k = 0; k != blocks; k += 8)
{
bigint_madd(x_j, y[k+0], z[j+k+0], carry, z + (j+k+0), &carry);
bigint_madd(x_j, y[k+1], z[j+k+1], carry, z + (j+k+1), &carry);
bigint_madd(x_j, y[k+2], z[j+k+2], carry, z + (j+k+2), &carry);
bigint_madd(x_j, y[k+3], z[j+k+3], carry, z + (j+k+3), &carry);
bigint_madd(x_j, y[k+4], z[j+k+4], carry, z + (j+k+4), &carry);
bigint_madd(x_j, y[k+5], z[j+k+5], carry, z + (j+k+5), &carry);
bigint_madd(x_j, y[k+6], z[j+k+6], carry, z + (j+k+6), &carry);
bigint_madd(x_j, y[k+7], z[j+k+7], carry, z + (j+k+7), &carry);
}
for(u32bit k = blocks; k != y_size; k++)
bigint_madd(x_j, y[k], z[j+k], carry, z + (j+k), &carry);
z[j+y_size] = carry;
}
}
}
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