isl_qpolynomial_morph: properly handle change in number of variables

The original implementation would only substitute the actual variables
and not the integer divisions, but if the number of variables changes,
then the positions of the integer divisions change too and so they have
to be adjusted as well.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/isl_polynomial.c b/isl_polynomial.c
index b9b98e1..601d358 100644 (file)
--- a/isl_polynomial.c
+++ b/isl_polynomial.c
@@ -3270,6 +3270,7 @@ __isl_give isl_qpolynomial *isl_qpolynomial_morph(__isl_take isl_qpolynomial *qp
        __isl_take isl_morph *morph)
 {
        int i;
+       int n_sub;
        isl_ctx *ctx;
        struct isl_upoly *up;
        unsigned n_div;
@@ -3283,17 +3284,24 @@ __isl_give isl_qpolynomial *isl_qpolynomial_morph(__isl_take isl_qpolynomial *qp
        ctx = qp->dim->ctx;
        isl_assert(ctx, isl_dim_equal(qp->dim, morph->dom->dim), goto error);
 
-       subs = isl_calloc_array(ctx, struct isl_upoly *, morph->inv->n_row - 1);
+       n_sub = morph->inv->n_row - 1;
+       if (morph->inv->n_row != morph->inv->n_col)
+               n_sub += qp->div->n_row;
+       subs = isl_calloc_array(ctx, struct isl_upoly *, n_sub);
        if (!subs)
                goto error;
 
        for (i = 0; 1 + i < morph->inv->n_row; ++i)
                subs[i] = isl_upoly_from_affine(ctx, morph->inv->row[1 + i],
                                        morph->inv->row[0][0], morph->inv->n_col);
+       if (morph->inv->n_row != morph->inv->n_col)
+               for (i = 0; i < qp->div->n_row; ++i)
+                       subs[morph->inv->n_row - 1 + i] =
+                               isl_upoly_pow(ctx, morph->inv->n_col - 1 + i, 1);
 
-       qp->upoly = isl_upoly_subs(qp->upoly, 0, morph->inv->n_row - 1, subs);
+       qp->upoly = isl_upoly_subs(qp->upoly, 0, n_sub, subs);
 
-       for (i = 0; 1 + i < morph->inv->n_row; ++i)
+       for (i = 0; i < n_sub; ++i)
                isl_upoly_free(subs[i]);
        free(subs);