From 77db762d5bcd0266848d0a8def7c060335acf495 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Fri, 19 Sep 2008 11:50:36 +0200
Subject: [PATCH] add isl_set_remove_dims

---
 include/isl_set.h |  4 ++--
 isl_convex_hull.c | 18 +-----------------
 isl_map.c         | 33 ++++++++++++++++++++++++++++++---
 isl_map_piplib.c  |  2 +-
 isl_map_private.h |  2 ++
 5 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/include/isl_set.h b/include/isl_set.h
index 1a322a3..37627b0 100644
--- a/include/isl_set.h
+++ b/include/isl_set.h
@@ -78,8 +78,6 @@ void isl_basic_set_dump(struct isl_basic_set *bset,
 				FILE *out, int indent);
 struct isl_basic_set *isl_basic_set_swap_vars(
 		struct isl_basic_set *bset, unsigned n);
-struct isl_basic_set *isl_basic_set_drop_vars(
-		struct isl_basic_set *bset, unsigned first, unsigned n);
 struct isl_basic_set *isl_basic_set_intersect(
 		struct isl_basic_set *bset1,
 		struct isl_basic_set *bset2);
@@ -131,6 +129,8 @@ struct isl_set *isl_set_subtract(struct isl_set *set1, struct isl_set *set2);
 struct isl_set *isl_set_apply(struct isl_set *set, struct isl_map *map);
 struct isl_set *isl_set_fix_dim_si(struct isl_set *set,
 		unsigned dim, int value);
+struct isl_set *isl_set_remove_dims(struct isl_set *set,
+		unsigned first, unsigned n);
 
 void isl_set_dump(struct isl_set *set, FILE *out, int indent);
 struct isl_set *isl_set_swap_vars(struct isl_set *set, unsigned n);
diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index cf06434..6dbddf3 100644
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -818,23 +818,7 @@ error:
 static struct isl_set *set_project_out(struct isl_ctx *ctx,
 	struct isl_set *set, unsigned n)
 {
-	int i;
-
-	set = isl_set_cow(set);
-	if (!set)
-		return NULL;
-	
-	for (i = 0; i < set->n; ++i) {
-		set->p[i] = isl_basic_set_eliminate_vars(set->p[i],
-							    set->dim - n, n);
-		if (!set->p[i])
-			goto error;
-	}
-	set = isl_set_drop_vars(set, set->dim - n, n);
-	return set;
-error:
-	isl_set_free(set);
-	return NULL;
+	return isl_set_remove_dims(set, set->dim - n, n);
 }
 
 /* If the number of linearly independent bounds we found is smaller
diff --git a/isl_map.c b/isl_map.c
index 2dae3f1..54eb8ed 100644
--- a/isl_map.c
+++ b/isl_map.c
@@ -610,7 +610,7 @@ static void constraint_drop_vars(isl_int *c, unsigned n, unsigned rem)
 	isl_seq_clr(c + rem, n);
 }
 
-struct isl_basic_set *isl_basic_set_drop_vars(
+struct isl_basic_set *isl_basic_set_drop_dims(
 		struct isl_basic_set *bset, unsigned first, unsigned n)
 {
 	int i;
@@ -648,7 +648,7 @@ error:
 	return NULL;
 }
 
-struct isl_set *isl_set_drop_vars(
+static struct isl_set *isl_set_drop_dims(
 		struct isl_set *set, unsigned first, unsigned n)
 {
 	int i;
@@ -665,7 +665,7 @@ struct isl_set *isl_set_drop_vars(
 		goto error;
 
 	for (i = 0; i < set->n; ++i) {
-		set->p[i] = isl_basic_set_drop_vars(set->p[i], first, n);
+		set->p[i] = isl_basic_set_drop_dims(set->p[i], first, n);
 		if (!set->p[i])
 			goto error;
 	}
@@ -1222,6 +1222,33 @@ struct isl_basic_set *isl_basic_set_eliminate_vars(
 			(struct isl_basic_map *)bset, pos, n);
 }
 
+/* Project out n dimensions starting at first using Fourier-Motzkin */
+struct isl_set *isl_set_remove_dims(struct isl_set *set,
+	unsigned first, unsigned n)
+{
+	int i;
+
+	if (n == 0)
+		return set;
+
+	set = isl_set_cow(set);
+	if (!set)
+		return NULL;
+	isl_assert(set->ctx, first+n <= set->dim, goto error);
+	
+	for (i = 0; i < set->n; ++i) {
+		set->p[i] = isl_basic_set_eliminate_vars(set->p[i],
+							set->nparam + first, n);
+		if (!set->p[i])
+			goto error;
+	}
+	set = isl_set_drop_dims(set, first, n);
+	return set;
+error:
+	isl_set_free(set);
+	return NULL;
+}
+
 /* Elimininate divs based on inequalities
  */
 static struct isl_basic_map *eliminate_divs_ineq(
diff --git a/isl_map_piplib.c b/isl_map_piplib.c
index 95879ed..062a4b2 100644
--- a/isl_map_piplib.c
+++ b/isl_map_piplib.c
@@ -215,7 +215,7 @@ static struct isl_map *scan_quast_r(struct scan_data *data, PipQuast *q,
 		/* not interested in rest if no sol */
 		struct isl_basic_set *bset;
 		bset = isl_basic_set_from_basic_map(isl_basic_map_copy(bmap));
-		bset = isl_basic_set_drop_vars(bset, bmap->n_in, bmap->n_out);
+		bset = isl_basic_set_drop_dims(bset, bmap->n_in, bmap->n_out);
 		if (!bset)
 			goto error;
 		*data->rest = isl_set_add(*data->rest, bset);
diff --git a/isl_map_private.h b/isl_map_private.h
index 6d7c302..9cf195f 100644
--- a/isl_map_private.h
+++ b/isl_map_private.h
@@ -41,6 +41,8 @@ struct isl_basic_set *isl_basic_map_underlying_set(struct isl_basic_map *bmap);
 struct isl_set *isl_map_underlying_set(struct isl_map *map);
 struct isl_basic_map *isl_basic_map_overlying_set(struct isl_basic_set *bset,
 	struct isl_basic_map *like);
+struct isl_basic_set *isl_basic_set_drop_dims(
+		struct isl_basic_set *bset, unsigned first, unsigned n);
 
 struct isl_map *isl_map_remove_empty_parts(struct isl_map *map);
 struct isl_set *isl_set_remove_empty_parts(struct isl_set *set);
-- 
2.7.4