isl_mat_extend: properly extend matrices with reordered rows

diff --git a/isl_mat.c b/isl_mat.c
index aa68941..10b81e3 100644 (file)
--- a/isl_mat.c
+++ b/isl_mat.c
@@ -40,6 +40,7 @@ struct isl_mat *isl_mat_extend(struct isl_ctx *ctx, struct isl_mat *mat,
        unsigned n_row, unsigned n_col)
 {
        int i;
+       isl_int *old;
 
        if (!mat)
                return NULL;
@@ -64,6 +65,7 @@ struct isl_mat *isl_mat_extend(struct isl_ctx *ctx, struct isl_mat *mat,
                goto error;
 
        assert(mat->ref == 1);
+       old = mat->block.data;
        mat->block = isl_blk_extend(ctx, mat->block, n_row * mat->n_col);
        if (isl_blk_is_error(mat->block))
                goto error;
@@ -71,7 +73,9 @@ struct isl_mat *isl_mat_extend(struct isl_ctx *ctx, struct isl_mat *mat,
        if (!mat->row)
                goto error;
 
-       for (i = 0; i < n_row; ++i)
+       for (i = 0; i < mat->n_row; ++i)
+               mat->row[i] = mat->block.data + (mat->row[i] - old);
+       for (i = mat->n_row; i < n_row; ++i)
                mat->row[i] = mat->block.data + i * mat->n_col;
        mat->n_row = n_row;