gf2matrix *make_identity_matrix(int bits)
{
mzd_t *I = mzd_init(bits, bits);
if (I)
mzd_set_ui(I, 1);
return I;
}
int _mzd_pluq_solve_left(mzd_t const *A, rci_t rank,
mzp_t const *P, mzp_t const *Q,
mzd_t *B, int const cutoff, int const inconsistency_check) {
/** A is supposed to store L lower triangular and U upper triangular
* B is modified in place
* (Bi's in the comments are just modified versions of B)
* PLUQ = A
* 1) P B2 = B1
* 2) L B3 = B2
* 3) U B4 = B3
* 4) Q B5 = B4
*/
int retval = 0;
/* P B2 = B1 or B2 = P^T B1 */
mzd_apply_p_left(B, P);
/* L B3 = B2 */
/* view on the upper part of L */
mzd_t const *LU = mzd_init_window_const(A, 0, 0, rank, rank);
mzd_t *Y1 = mzd_init_window(B, 0, 0, rank, B->ncols);
mzd_trsm_lower_left(LU, Y1, cutoff);
if (inconsistency_check) { /* Check for inconsistency */
/** FASTER without this check; update with the lower part of L
*/
mzd_t const *H = mzd_init_window_const(A, rank, 0, A->nrows, rank);
mzd_t *Y2 = mzd_init_window(B, rank, 0, A->nrows, B->ncols);
if(A->nrows < B->nrows) {
mzd_t *Y3 = mzd_init_window(B, A->nrows, 0, B->nrows, B->ncols);
mzd_set_ui(Y3, 0);
mzd_free_window(Y3);
}
mzd_addmul(Y2, H, Y1, cutoff);
/*
* test whether Y2 is the zero matrix
*/
if(!mzd_is_zero(Y2)) {
retval = -1;
}
mzd_free_window((mzd_t*)H);
mzd_free_window(Y2);
}
/* U B4 = B3 */
mzd_trsm_upper_left(LU, Y1, cutoff);
mzd_free_window((mzd_t*)LU);
mzd_free_window(Y1);
if (!inconsistency_check) {
/** Default is to set the undefined bits to zero if inconsistency
* has been checked then Y2 bits are already all zeroes thus this
* clearing is not needed
*/
for(rci_t i = rank; i < B->nrows; ++i) {
for(rci_t j = 0; j < B->ncols; j += m4ri_radix) {
mzd_clear_bits(B, i, j, MIN(m4ri_radix, B->ncols - j));
}
}
}
/* Q B5 = B4 or B5 = Q^T B4 */
mzd_apply_p_left_trans(B, Q);
/* P L U Q B5 = B1 */
__M4RI_DD_MZD(B);
__M4RI_DD_INT(retval);
return retval;
}
void convert_to_identity(gf2matrix *m)
{
if (!m)
return;
mzd_set_ui(m, 1);
}
void clear_matrix(gf2matrix *m)
{
if (!m)
return;
mzd_set_ui(m, 0);
}
