/* Update the given lower bound on level such that it satisfies the stride
* constraint. The computation performed here is essentially the same
* as that performed in constraint_stride_lower_c.
*
* We update the constraint
*
* a i + f >= 0
*
* to
*
* i >= s * ceil((-f/a - d)/s) + d
*
* with s the stride and d the offset encoded in the stride constraint.
*/
CloogConstraint *cloog_constraint_stride_lower_bound(CloogConstraint *c,
int level, CloogStride *stride)
{
isl_constraint *stride_c = cloog_constraint_to_isl(stride->constraint);
isl_constraint *bound = cloog_constraint_to_isl(c);
isl_aff *offset;
isl_aff *lower;
lower = isl_constraint_get_bound(bound, isl_dim_set, level - 1);
isl_constraint_free(bound);
offset = extract_stride_offset(stride_c, level, stride);
lower = isl_aff_sub(lower, isl_aff_copy(offset));
lower = isl_aff_scale_down(lower, stride->stride);
lower = isl_aff_ceil(lower);
lower = isl_aff_scale(lower, stride->stride);
lower = isl_aff_add(lower, offset);
lower = isl_aff_neg(lower);
lower = isl_aff_add_coefficient_si(lower, isl_dim_in, level - 1, 1);
bound = isl_inequality_from_aff(lower);
return cloog_constraint_from_isl_constraint(bound);
}
/* Make a copy of "si" and return it.
*/
__isl_give isl_stride_info *isl_stride_info_copy(
__isl_keep isl_stride_info *si)
{
if (!si)
return NULL;
return isl_stride_info_alloc(isl_val_copy(si->stride),
isl_aff_copy(si->offset));
}
/* Return the offset of "si".
*/
__isl_give isl_aff *isl_stride_info_get_offset(__isl_keep isl_stride_info *si)
{
if (!si)
return NULL;
return isl_aff_copy(si->offset);
}
