diff options
Diffstat (limited to 'isl_equalities.c')
| -rw-r--r-- | isl_equalities.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/isl_equalities.c b/isl_equalities.c index 44cf8f06..83572a07 100644 --- a/isl_equalities.c +++ b/isl_equalities.c @@ -514,7 +514,7 @@ __isl_give isl_mat *isl_mat_variable_compression(__isl_take isl_mat *B, isl_mat_free(U); if (T2) { isl_mat_free(*T2); - *T2 = NULL; + *T2 = isl_mat_alloc(ctx, 0, 1 + dim); } return isl_mat_alloc(ctx, 1 + dim, 0); } @@ -544,6 +544,32 @@ error: return NULL; } +/* Return "bset" and set *T and *T2 to the identity transformation + * on "bset" (provided T and T2 are not NULL). + */ +static __isl_give isl_basic_set *return_with_identity( + __isl_take isl_basic_set *bset, __isl_give isl_mat **T, + __isl_give isl_mat **T2) +{ + unsigned dim; + isl_mat *id; + + if (!bset) + return NULL; + if (!T && !T2) + return bset; + + dim = isl_basic_set_dim(bset, isl_dim_set); + id = isl_mat_identity(isl_basic_map_get_ctx(bset), 1 + dim); + if (T) + *T = isl_mat_copy(id); + if (T2) + *T2 = isl_mat_copy(id); + isl_mat_free(id); + + return bset; +} + /* Use the n equalities of bset to unimodularly transform the * variables x such that n transformed variables x1' have a constant value * and rewrite the constraints of bset in terms of the remaining @@ -568,7 +594,7 @@ static struct isl_basic_set *compress_variables( dim = isl_basic_set_n_dim(bset); isl_assert(bset->ctx, bset->n_eq <= dim, goto error); if (bset->n_eq == 0) - return bset; + return return_with_identity(bset, T, T2); B = isl_mat_sub_alloc6(bset->ctx, bset->eq, 0, bset->n_eq, 0, 1 + dim); TC = isl_mat_variable_compression(B, T2); @@ -604,7 +630,7 @@ struct isl_basic_set *isl_basic_set_remove_equalities( isl_assert(bset->ctx, isl_basic_set_n_param(bset) == 0, goto error); bset = isl_basic_set_gauss(bset, NULL); if (ISL_F_ISSET(bset, ISL_BASIC_SET_EMPTY)) - return bset; + return return_with_identity(bset, T, T2); bset = compress_variables(bset, T, T2); return bset; error: |