From 91f0376fe758d2921854d2e9863599426dfc4fce Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Tue, 3 Dec 2013 13:25:44 +0100
Subject: [PATCH] add isl_union_map_project_out

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 doc/user.pod            |  6 ++++++
 include/isl/union_map.h |  4 ++++
 isl_union_map.c         | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)

diff --git a/doc/user.pod b/doc/user.pod
index ce7f45a6..cd2bb5f8 100644
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -2220,6 +2220,9 @@ change over different versions of C<isl>.
 		__isl_take isl_union_set *uset);
 
 	#include <isl/union_map.h>
+	__isl_give isl_union_map *isl_union_map_project_out(
+		__isl_take isl_union_map *umap,
+		enum isl_dim_type type, unsigned first, unsigned n);
 	__isl_give isl_set *isl_union_map_params(
 		__isl_take isl_union_map *umap);
 	__isl_give isl_union_set *isl_union_map_domain(
@@ -2227,6 +2230,9 @@ change over different versions of C<isl>.
 	__isl_give isl_union_set *isl_union_map_range(
 		__isl_take isl_union_map *umap);
 
+The function C<isl_union_map_project_out> can only project out
+parameters.
+
 	#include <isl/map.h>
 	__isl_give isl_basic_map *isl_basic_map_domain_map(
 		__isl_take isl_basic_map *bmap);
diff --git a/include/isl/union_map.h b/include/isl/union_map.h
index feaaf2fb..61611f64 100644
--- a/include/isl/union_map.h
+++ b/include/isl/union_map.h
@@ -144,6 +144,10 @@ __isl_give isl_union_map *isl_union_map_deltas_map(
 __isl_export
 __isl_give isl_union_map *isl_union_set_identity(__isl_take isl_union_set *uset);
 
+__isl_give isl_union_map *isl_union_map_project_out(
+	__isl_take isl_union_map *umap,
+	enum isl_dim_type type, unsigned first, unsigned n);
+
 __isl_export
 int isl_union_map_is_empty(__isl_keep isl_union_map *umap);
 __isl_export
diff --git a/isl_union_map.c b/isl_union_map.c
index 0047a5b5..bd229038 100644
--- a/isl_union_map.c
+++ b/isl_union_map.c
@@ -2984,3 +2984,60 @@ __isl_give isl_union_set *isl_union_set_reset_user(
 {
 	return isl_union_map_reset_user(uset);
 }
+
+/* Internal data structure for isl_union_map_project_out.
+ * "type", "first" and "n" are the arguments for the isl_map_project_out
+ * call.
+ * "res" collects the results.
+ */
+struct isl_union_map_project_out_data {
+	enum isl_dim_type type;
+	unsigned first;
+	unsigned n;
+
+	isl_union_map *res;
+};
+
+/* Turn the data->n dimensions of type data->type, starting at data->first
+ * into existentially quantified variables and add the result to data->res.
+ */
+static int project_out(__isl_take isl_map *map, void *user)
+{
+	struct isl_union_map_project_out_data *data = user;
+
+	map = isl_map_project_out(map, data->type, data->first, data->n);
+	data->res = isl_union_map_add_map(data->res, map);
+
+	return 0;
+}
+
+/* Turn the "n" dimensions of type "type", starting at "first"
+ * into existentially quantified variables.
+ * Since the space of an isl_union_map only contains parameters,
+ * type is required to be equal to isl_dim_param.
+ */
+__isl_give isl_union_map *isl_union_map_project_out(
+	__isl_take isl_union_map *umap,
+	enum isl_dim_type type, unsigned first, unsigned n)
+{
+	isl_space *space;
+	struct isl_union_map_project_out_data data = { type, first, n };
+
+	if (!umap)
+		return NULL;
+
+	if (type != isl_dim_param)
+		isl_die(isl_union_map_get_ctx(umap), isl_error_invalid,
+			"can only project out parameters",
+			return isl_union_map_free(umap));
+
+	space = isl_union_map_get_space(umap);
+	space = isl_space_drop_dims(space, type, first, n);
+	data.res = isl_union_map_empty(space);
+	if (isl_union_map_foreach_map(umap, &project_out, &data) < 0)
+		data.res = isl_union_map_free(data.res);
+
+	isl_union_map_free(umap);
+
+	return data.res;
+}
-- 
2.11.4.GIT