From b99709f113b02fc5b997f59ad1b6aebefe922275 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Wed, 16 Nov 2011 12:05:09 +0100
Subject: [PATCH] add pet_scop_writes

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 scop.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 scop.h |  2 ++
 2 files changed, 56 insertions(+)

diff --git a/scop.c b/scop.c
index b64d51f..ea9e70a 100644
--- a/scop.c
+++ b/scop.c
@@ -1698,3 +1698,57 @@ __isl_give isl_union_map *pet_scop_collect_schedule(struct pet_scop *scop)
 
 	return schedule;
 }
+
+/* Does expression "expr" write to "id"?
+ */
+static int expr_writes(struct pet_expr *expr, __isl_keep isl_id *id)
+{
+	int i;
+	isl_id *write_id;
+
+	for (i = 0; i < expr->n_arg; ++i) {
+		int writes = expr_writes(expr->args[i], id);
+		if (writes < 0 || writes)
+			return writes;
+	}
+
+	if (expr->type != pet_expr_access)
+		return 0;
+	if (!expr->acc.write)
+		return 0;
+	if (!isl_map_has_tuple_id(expr->acc.access, isl_dim_out))
+		return 0;
+
+	write_id = isl_map_get_tuple_id(expr->acc.access, isl_dim_out);
+	isl_id_free(write_id);
+
+	if (!write_id)
+		return -1;
+
+	return write_id == id;
+}
+
+/* Does statement "stmt" write to "id"?
+ */
+static int stmt_writes(struct pet_stmt *stmt, __isl_keep isl_id *id)
+{
+	return expr_writes(stmt->body, id);
+}
+
+/* Is there any write access in "scop" that accesses "id"?
+ */
+int pet_scop_writes(struct pet_scop *scop, __isl_keep isl_id *id)
+{
+	int i;
+
+	if (!scop)
+		return -1;
+
+	for (i = 0; i < scop->n_stmt; ++i) {
+		int writes = stmt_writes(scop->stmts[i], id);
+		if (writes < 0 || writes)
+			return writes;
+	}
+
+	return 0;
+}
diff --git a/scop.h b/scop.h
index c0b65fc..aa07df7 100644
--- a/scop.h
+++ b/scop.h
@@ -62,6 +62,8 @@ struct pet_expr *pet_expr_foreach_access(struct pet_expr *expr,
 	__isl_give isl_map *(*fn)(__isl_take isl_map *access, void *user),
 	void *user);
 
+int pet_scop_writes(struct pet_scop *scop, __isl_keep isl_id *id);
+
 #if defined(__cplusplus)
 }
 #endif
-- 
2.11.4.GIT