void cloog_constraint_clear(CloogConstraint *constraint)
{
int k;
for (k = 1; k <= constraint->set->M.NbColumns - 2; k++)
cloog_int_set_si(constraint->line[0][k], 0);
}
/**
* cloog_equal_add function:
* This function updates the row (level-1) of the equality matrix (equal) with
* the row that corresponds to the row (line) of the matrix (matrix).
* - equal is the matrix of equalities,
* - matrix is the matrix of constraints,
* - level is the column number in matrix of the element which is 'equal to',
* - line is the line number in matrix of the constraint we want to study,
* - the infos structure gives the user all options on code printing and more.
**
* - July 2nd 2002: first version.
* - October 19th 2005: Addition of the once-time-loop specific processing.
*/
void cloog_equal_add(CloogEqualities *equal, CloogConstraintSet *constraints,
int level, CloogConstraint *line, int nb_par)
{
int j;
CloogConstraint *i = cloog_constraint_invalid();
CloogMatrix *matrix = &constraints->M;
/* If we are in the case of a loop running once, this means that the equality
* comes from an inequality. Here we find this inequality.
*/
if (!cloog_constraint_is_valid(line))
{ for (i = cloog_constraint_first(constraints);
cloog_constraint_is_valid(i); i = cloog_constraint_next(i))
if ((!cloog_int_is_zero(i->line[0][0]))&& (!cloog_int_is_zero(i->line[0][level])))
{ line = i ;
/* Since in once-time-loops, equalities derive from inequalities, we
* may have to offset the values. For instance if we have 2i>=3, the
* equality is in fact i=2. This may happen when the level coefficient is
* not 1 or -1 and the scalar value is not zero. In any other case (e.g.,
* if the inequality is an expression including outer loop counters or
* parameters) the once time loop would not have been detected
* because of floord and ceild functions.
*/
if (cloog_int_ne_si(i->line[0][level],1) &&
cloog_int_ne_si(i->line[0][level],-1) &&
!cloog_int_is_zero(i->line[0][matrix->NbColumns-1])) {
cloog_int_t denominator;
cloog_int_init(denominator);
cloog_int_abs(denominator, i->line[0][level]);
cloog_int_fdiv_q(i->line[0][matrix->NbColumns-1],
i->line[0][matrix->NbColumns-1], denominator);
cloog_int_set_si(i->line[0][level], cloog_int_sgn(i->line[0][level]));
cloog_int_clear(denominator);
}
break ;
}
}
assert(cloog_constraint_is_valid(line));
/* We update the line of equal corresponding to level:
* - the first element gives the equality type,
*/
equal->types[level-1] = cloog_constraint_equal_type(line, level);
/* - the other elements corresponding to the equality itself
* (the iterators up to level, then the parameters and the scalar).
*/
for (j=1;j<=level;j++)
cloog_int_set(equal->constraints->M.p[level-1][j], line->line[0][j]);
for (j = 0; j < nb_par + 1; j++)
cloog_int_set(equal->constraints->M.p[level-1][equal->constraints->M.NbColumns-j-1],
line->line[0][line->set->M.NbColumns-j-1]);
if (cloog_constraint_is_valid(i))
cloog_constraint_release(line);
cloog_equal_update(equal, level, nb_par);
}
/* Computes x, y and g such that g = gcd(a,b) and a*x+b*y = g */
static void Euclid(cloog_int_t a, cloog_int_t b,
cloog_int_t *x, cloog_int_t *y, cloog_int_t *g)
{
cloog_int_t c, d, e, f, tmp;
cloog_int_init(c);
cloog_int_init(d);
cloog_int_init(e);
cloog_int_init(f);
cloog_int_init(tmp);
cloog_int_abs(c, a);
cloog_int_abs(d, b);
cloog_int_set_si(e, 1);
cloog_int_set_si(f, 0);
while (cloog_int_is_pos(d)) {
cloog_int_tdiv_q(tmp, c, d);
cloog_int_mul(tmp, tmp, f);
cloog_int_sub(e, e, tmp);
cloog_int_tdiv_q(tmp, c, d);
cloog_int_mul(tmp, tmp, d);
cloog_int_sub(c, c, tmp);
cloog_int_swap(c, d);
cloog_int_swap(e, f);
}
cloog_int_set(*g, c);
if (cloog_int_is_zero(a))
cloog_int_set_si(*x, 0);
else if (cloog_int_is_pos(a))
cloog_int_set(*x, e);
else cloog_int_neg(*x, e);
if (cloog_int_is_zero(b))
cloog_int_set_si(*y, 0);
else {
cloog_int_mul(tmp, a, *x);
cloog_int_sub(tmp, c, tmp);
cloog_int_divexact(*y, tmp, b);
}
cloog_int_clear(c);
cloog_int_clear(d);
cloog_int_clear(e);
cloog_int_clear(f);
cloog_int_clear(tmp);
}
static
CloogMatrix* convert_to_cloogmatrix(scoplib_matrix_p mat)
{
CloogMatrix* ret = cloog_matrix_alloc (mat->NbRows, mat->NbColumns);
int i, j;
for (i = 0; i < mat->NbRows; ++i)
for (j = 0; j < mat->NbColumns; ++j)
cloog_int_set_si(ret->p[i][j], SCOPVAL_get_si(mat->p[i][j]));
return ret;
}
/**
* cloog_matrix_alloc:
* Allocate a CloogMatrix data structure with NbRows rows and NbColumns columns.
* All values are initialized to 0.
* This method returns a pointer to the data structure if successful or a NULL
* pointer otherwise.
*/
CloogMatrix *cloog_matrix_alloc(unsigned NbRows, unsigned NbColumns)
{
CloogMatrix *matrix;
cloog_int_t **p, *q;
unsigned int i, j;
matrix = (CloogMatrix *)malloc(sizeof(CloogMatrix));
if (!matrix)
return NULL;
matrix->NbRows = NbRows;
matrix->NbColumns = NbColumns;
if (!NbRows || !NbColumns) {
matrix->p = NULL;
matrix->p_Init = NULL;
return matrix;
}
p = (cloog_int_t **)malloc(NbRows * sizeof(cloog_int_t *));
if (p == NULL) {
free (matrix);
return NULL;
}
q = (cloog_int_t *)malloc(NbRows * NbColumns * sizeof(cloog_int_t));
if (q == NULL) {
free (matrix);
free (p);
return NULL;
}
matrix->p = p;
matrix->p_Init = q;
for (i = 0; i < NbRows; i++) {
*p++ = q;
for (j = 0; j < NbColumns; j++) {
cloog_int_init(*(q+j));
cloog_int_set_si(*(q+j), 0);
}
q += NbColumns;
}
return matrix;
}
/**
* cloog_constraint_set_simplify function:
* this function simplify all constraints inside the matrix "matrix" thanks to
* an equality matrix "equal" that gives for some elements of the affine
* constraint an equality with other elements, preferably constants.
* For instance, if a row of the matrix contains i+j+3>=0 and the equality
* matrix gives i=n and j=2, the constraint is simplified to n+3>=0. The
* simplified constraints are returned back inside a new simplified matrix.
* - matrix is the set of constraints to simplify,
* - equal is the matrix of equalities,
* - level is a level we don't want to simplify (-1 if none),
* - nb_par is the number of parameters of the program.
**
* - November 4th 2005: first version.
*/
CloogConstraintSet *cloog_constraint_set_simplify(CloogConstraintSet *constraints,
CloogEqualities *equal, int level, int nb_par)
{ int i, j, k ;
struct cloog_vec *vector;
CloogMatrix *simplified;
CloogMatrix *matrix = &constraints->M;
if (matrix == NULL)
return NULL ;
/* The simplified matrix is such that each row has been simplified thanks
* tho the "equal" matrix. We allocate the memory for the simplified matrix,
* then for each row of the original matrix, we compute the simplified
* vector and we copy its content into the according simplified row.
*/
simplified = cloog_matrix_alloc(matrix->NbRows, matrix->NbColumns);
for (i=0;i<matrix->NbRows;i++)
{ vector = cloog_equal_vector_simplify(equal, matrix->p[i],
matrix->NbColumns, level, nb_par);
for (j=0;j<matrix->NbColumns;j++)
cloog_int_set(simplified->p[i][j], vector->p[j]);
cloog_vec_free(vector);
}
/* After simplification, it may happen that few constraints are the same,
* we remove them here by replacing them with 0=0 constraints.
*/
for (i=0;i<simplified->NbRows;i++)
for (j=i+1;j<simplified->NbRows;j++)
{ for (k=0;k<simplified->NbColumns;k++)
if (cloog_int_ne(simplified->p[i][k],simplified->p[j][k]))
break ;
if (k == matrix->NbColumns)
{ for (k=0;k<matrix->NbColumns;k++)
cloog_int_set_si(simplified->p[j][k],0);
}
}
return cloog_constraint_set_from_cloog_matrix(simplified);
}
/**
* Reduce the modulo guard expressed by "contraints" using equalities
* found in outer nesting levels (stored in "equal").
* The modulo guard may be an equality or a pair of inequalities.
* In case of a pair of inequalities, "constraints" only contains the
* upper bound and *bound contains the bound on the
* corresponding modulo expression. The bound is left untouched by
* this function.
*/
CloogConstraintSet *cloog_constraint_set_reduce(CloogConstraintSet *constraints,
int level, CloogEqualities *equal, int nb_par, cloog_int_t *bound)
{
int i, j, k, len, len2, nb_iter;
struct cloog_vec *line_vector2;
cloog_int_t *line, *line2, val, x, y, g;
len = constraints->M.NbColumns;
len2 = cloog_equal_total_dimension(equal) + 2;
nb_iter = len - 2 - nb_par;
cloog_int_init(val);
cloog_int_init(x);
cloog_int_init(y);
cloog_int_init(g);
line_vector2 = cloog_vec_alloc(len2);
line2 = line_vector2->p;
line = constraints->M.p[0];
if (cloog_int_is_pos(line[level]))
cloog_seq_neg(line+1, line+1, len-1);
cloog_int_neg(line[level], line[level]);
assert(cloog_int_is_pos(line[level]));
for (i = nb_iter; i >= 1; --i) {
if (i == level)
continue;
cloog_int_fdiv_r(line[i], line[i], line[level]);
if (cloog_int_is_zero(line[i]))
continue;
/* Look for an earlier variable that is also a multiple of line[level]
* and check whether we can use the corresponding affine expression
* to "reduce" the modulo guard, where reduction means that we eliminate
* a variable, possibly at the expense of introducing other variables
* with smaller index.
*/
for (j = level-1; j >= 0; --j) {
CloogConstraint *equal_constraint;
if (cloog_equal_type(equal, j+1) != EQTYPE_EXAFFINE)
continue;
equal_constraint = cloog_equal_constraint(equal, j);
cloog_constraint_coefficient_get(equal_constraint, j, &val);
if (!cloog_int_is_divisible_by(val, line[level])) {
cloog_constraint_release(equal_constraint);
continue;
}
cloog_constraint_coefficient_get(equal_constraint, i-1, &val);
if (cloog_int_is_divisible_by(val, line[level])) {
cloog_constraint_release(equal_constraint);
continue;
}
for (k = j; k > i; --k) {
cloog_constraint_coefficient_get(equal_constraint, k-1, &val);
if (cloog_int_is_zero(val))
continue;
if (!cloog_int_is_divisible_by(val, line[level]))
break;
}
if (k > i) {
cloog_constraint_release(equal_constraint);
continue;
}
cloog_constraint_coefficient_get(equal_constraint, i-1, &val);
Euclid(val, line[level], &x, &y, &g);
if (!cloog_int_is_divisible_by(val, line[i])) {
cloog_constraint_release(equal_constraint);
continue;
}
cloog_int_divexact(val, line[i], g);
cloog_int_neg(val, val);
cloog_int_mul(val, val, x);
cloog_int_set_si(y, 1);
/* Add (equal->p[j][i])^{-1} * line[i] times the equality */
cloog_constraint_copy_coefficients(equal_constraint, line2+1);
cloog_seq_combine(line+1, y, line+1, val, line2+1, i);
cloog_seq_combine(line+len-nb_par-1, y, line+len-nb_par-1,
val, line2+len2-nb_par-1, nb_par+1);
cloog_constraint_release(equal_constraint);
break;
}
}
cloog_vec_free(line_vector2);
cloog_int_clear(val);
cloog_int_clear(x);
cloog_int_clear(y);
cloog_int_clear(g);
/* Make sure the line is not inverted again in the calling function. */
cloog_int_neg(line[level], line[level]);
return constraints;
}
