From d1cf3bf14c540af05df3ef55d5cbee233d9a2525 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Fri, 9 Mar 2012 11:24:26 +0100
Subject: [PATCH] PetScan::resolve_nested: detect and remove duplicate filters

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 scan.cc                      | 45 ++++++++++++++++++++++++++++++++++++++++++++
 tests/dynamic_condition.c    | 16 ++++++++++++++++
 tests/dynamic_condition.scop | 44 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 105 insertions(+)
 create mode 100644 tests/dynamic_condition.c
 create mode 100644 tests/dynamic_condition.scop

diff --git a/scan.cc b/scan.cc
index 6069826..2e4cca9 100644
--- a/scan.cc
+++ b/scan.cc
@@ -3024,6 +3024,50 @@ error:
 	return NULL;
 }
 
+/* Check whether any of the arguments i of "stmt" starting at position "n"
+ * is equal to one of the first "n" arguments j.
+ * If so, combine the constraints on arguments i and j and remove
+ * argument i.
+ */
+static struct pet_stmt *remove_duplicate_arguments(struct pet_stmt *stmt, int n)
+{
+	int i, j;
+	isl_map *map;
+
+	if (!stmt)
+		return NULL;
+	if (n == 0)
+		return stmt;
+	if (n == stmt->n_arg)
+		return stmt;
+
+	map = isl_set_unwrap(stmt->domain);
+
+	for (i = stmt->n_arg - 1; i >= n; --i) {
+		for (j = 0; j < n; ++j)
+			if (pet_expr_is_equal(stmt->args[i], stmt->args[j]))
+				break;
+		if (j >= n)
+			continue;
+
+		map = isl_map_equate(map, isl_dim_out, i, isl_dim_out, j);
+		map = isl_map_project_out(map, isl_dim_out, i, 1);
+
+		pet_expr_free(stmt->args[i]);
+		for (j = i; j + 1 < stmt->n_arg; ++j)
+			stmt->args[j] = stmt->args[j + 1];
+		stmt->n_arg--;
+	}
+
+	stmt->domain = isl_map_wrap(map);
+	if (!stmt->domain)
+		goto error;
+	return stmt;
+error:
+	pet_stmt_free(stmt);
+	return NULL;
+}
+
 /* Look for parameters in the iteration domain of "stmt" that
  * refer to nested accesses.  In particular, these are
  * parameters with no name.
@@ -3094,6 +3138,7 @@ struct pet_stmt *PetScan::resolve_nested(struct pet_stmt *stmt)
 	isl_map_free(map);
 
 	stmt = remove_nested_parameters(stmt);
+	stmt = remove_duplicate_arguments(stmt, n);
 
 	return stmt;
 error:
diff --git a/tests/dynamic_condition.c b/tests/dynamic_condition.c
new file mode 100644
index 0000000..ca8e5b2
--- /dev/null
+++ b/tests/dynamic_condition.c
@@ -0,0 +1,16 @@
+int f(void);
+
+void foo()
+{
+    int i, j, a[100];
+
+#pragma scop
+    for (i = 0; i < 100; ++i) {
+	j = f();
+	if (j <= 1) {
+	    if (j >= 0)
+		a[i] = i;
+	}
+    }
+#pragma endscop
+}
diff --git a/tests/dynamic_condition.scop b/tests/dynamic_condition.scop
new file mode 100644
index 0000000..d2977a5
--- /dev/null
+++ b/tests/dynamic_condition.scop
@@ -0,0 +1,44 @@
+context: '{  :  }'
+arrays:
+- context: '{  :  }'
+  extent: '{ j[] }'
+  element_type: int
+  element_size: 4
+- context: '{  :  }'
+  extent: '{ a[i0] : i0 >= 0 and i0 <= 99 }'
+  element_type: int
+  element_size: 4
+statements:
+- line: 9
+  domain: '{ S_0[i] : i >= 0 and i <= 99 }'
+  schedule: '{ S_0[i] -> [0, i, 0] }'
+  body:
+    type: binary
+    operation: =
+    arguments:
+    - type: access
+      relation: '{ S_0[i] -> j[] }'
+      read: 0
+      write: 1
+    - type: call
+      name: f
+- line: 12
+  domain: '{ [S_3[i] -> [j]] : j >= 0 and j <= 1 and i >= 0 and i <= 99 }'
+  schedule: '{ S_3[i] -> [0, i, 1, 0] }'
+  body:
+    type: binary
+    operation: =
+    arguments:
+    - type: access
+      relation: '{ S_3[i] -> a[i] }'
+      read: 0
+      write: 1
+    - type: access
+      relation: '{ S_3[i] -> [i] }'
+      read: 1
+      write: 0
+  arguments:
+  - type: access
+    relation: '{ S_3[i] -> j[] }'
+    read: 1
+    write: 0
-- 
2.11.4.GIT