From 5ef446319801cc9de30fc7ca9b8d420ca7cfb788 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <sven@cerebras.net>
Date: Fri, 15 Jul 2022 17:09:11 +0200
Subject: [PATCH] add exported isl_map_domain_reverse

This complements the already exported isl_map_range_reverse and
isl_set_wrapped_reverse.

Signed-off-by: Sven Verdoolaege <sven@cerebras.net>
---
 doc/user.pod      |  2 ++
 include/isl/map.h |  2 ++
 isl_map.c         | 25 +++++++++++++++++++++++++
 isl_test2.cc      |  9 +++++++++
 4 files changed, 38 insertions(+)

diff --git a/doc/user.pod b/doc/user.pod
index ac25da6b..278c47b2 100644
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -5449,6 +5449,8 @@ earlier dimensions before those that involve later dimensions.
 		__isl_take isl_basic_map *bmap);
 	__isl_give isl_map *isl_map_reverse(
 		__isl_take isl_map *map);
+	__isl_give isl_map *isl_map_domain_reverse(
+		__isl_take isl_map *map);
 	__isl_give isl_map *isl_map_range_reverse(
 		__isl_take isl_map *map);
 
diff --git a/include/isl/map.h b/include/isl/map.h
index f4a50a98..20da7a99 100644
--- a/include/isl/map.h
+++ b/include/isl/map.h
@@ -326,6 +326,8 @@ __isl_give isl_map *isl_map_copy(__isl_keep isl_map *map);
 __isl_export
 __isl_give isl_map *isl_map_reverse(__isl_take isl_map *map);
 __isl_export
+__isl_give isl_map *isl_map_domain_reverse(__isl_take isl_map *map);
+__isl_export
 __isl_give isl_map *isl_map_range_reverse(__isl_take isl_map *map);
 __isl_export
 __isl_give isl_map *isl_map_union(
diff --git a/isl_map.c b/isl_map.c
index 4a2f0f0b..fb33f885 100644
--- a/isl_map.c
+++ b/isl_map.c
@@ -6,6 +6,7 @@
  * Copyright 2016      INRIA Paris
  * Copyright 2016      Sven Verdoolaege
  * Copyright 2018-2019 Cerebras Systems
+ * Copyright 2022      Cerebras Systems
  *
  * Use of this software is governed by the MIT license
  *
@@ -4031,6 +4032,22 @@ static __isl_give isl_basic_map *isl_basic_map_reverse_wrapped(
 	return bmap;
 }
 
+/* Given a basic map (A -> B) -> C, return the corresponding basic map
+ * (B -> A) -> C.
+ */
+static __isl_give isl_basic_map *isl_basic_map_domain_reverse(
+	__isl_take isl_basic_map *bmap)
+{
+	isl_space *space;
+
+	space = isl_basic_map_peek_space(bmap);
+	if (isl_space_check_domain_is_wrapping(space) < 0)
+		return isl_basic_map_free(bmap);
+	bmap = isl_basic_map_reverse_wrapped(bmap, isl_dim_in);
+
+	return bmap;
+}
+
 /* Given a basic map A -> (B -> C), return the corresponding basic map
  * A -> (C -> B).
  */
@@ -7215,6 +7232,14 @@ __isl_give isl_map *isl_map_reverse(__isl_take isl_map *map)
 					&isl_basic_map_reverse);
 }
 
+/* Given a map (A -> B) -> C, return the corresponding map (B -> A) -> C.
+ */
+__isl_give isl_map *isl_map_domain_reverse(__isl_take isl_map *map)
+{
+	return isl_map_transform(map, &isl_space_domain_reverse,
+					&isl_basic_map_domain_reverse);
+}
+
 /* Given a map A -> (B -> C), return the corresponding map A -> (C -> B).
  */
 __isl_give isl_map *isl_map_range_reverse(__isl_take isl_map *map)
diff --git a/isl_test2.cc b/isl_test2.cc
index ffb7cd8c..d8bcf2ba 100644
--- a/isl_test2.cc
+++ b/isl_test2.cc
@@ -504,6 +504,15 @@ static void test_reverse(isl::ctx ctx)
 	  "{ [B[y] -> A[x]] -> T[5*(x // 2) + 7*(y // 3) : x > y, 0] }" },
 	});
 
+	C(&isl::map::domain_reverse, {
+	{ "{ [A[] -> B[]] -> [C[] -> D[]] }",
+	  "{ [B[] -> A[]] -> [C[] -> D[]] }" },
+	{ "{ N[B[] -> C[]] -> A[] }",
+	  "{ [C[] -> B[]] -> A[] }" },
+	{ "{ N[B[x] -> B[y]] -> A[] }",
+	  "{ N[B[*] -> B[*]] -> A[] }" },
+	});
+
 	C(&isl::union_map::range_reverse, {
 	{ "{ A[] -> [B[] -> C[]]; A[] -> B[]; A[0] -> N[B[1] -> B[2]] }",
 	  "{ A[] -> [C[] -> B[]]; A[0] -> N[B[2] -> B[1]] }" },
-- 
2.11.4.GIT