[optimzing] Fix codegen bug and improve type propagation

- don't bound the type if there are no relevant uses
- insert the bound type in the bounded block (this allows for condition
materialization without changing the logic there).
- add more comments
- add tests for BoundType generation
- fix GenerateTestAndBranch

Change-Id: I5c1fdda104da4a46775d207270220d410234a472

3 files changed, 64 insertions, 0 deletions

diff --git a/test/477-checker-bound-type/expected.txt b/test/477-checker-bound-type/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/477-checker-bound-type/expected.txt
diff --git a/test/477-checker-bound-type/info.txt b/test/477-checker-bound-type/info.txt
new file mode 100644
index 0000000..68c774a
--- /dev/null
+++ b/test/477-checker-bound-type/info.txt
@@ -0,0 +1,3 @@
+Tests that we only generate a bound type if we have relevant users.
+It also tests a code generator regression for GenerateTestAndBranch which
+didn't take into account NullConstants.
diff --git a/test/477-checker-bound-type/src/Main.java b/test/477-checker-bound-type/src/Main.java
new file mode 100644
index 0000000..b30028d
--- /dev/null
+++ b/test/477-checker-bound-type/src/Main.java
@@ -0,0 +1,61 @@
+/*
+* Copyright (C) 2015 The Android Open Source Project
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+
+public class Main {
+
+  // CHECK-START: java.lang.Object Main.boundTypeForIf(java.lang.Object) reference_type_propagation (after)
+  // CHECK:     BoundType
+  public static Object boundTypeForIf(Object a) {
+    if (a != null) {
+      return a.toString();
+    } else {
+      return null;
+    }
+  }
+
+  // CHECK-START: java.lang.Object Main.boundTypeForInstanceOf(java.lang.Object) reference_type_propagation (after)
+  // CHECK:     BoundType
+  public static Object boundTypeForInstanceOf(Object a) {
+    if (a instanceof Main) {
+      return (Main)a;
+    } else {
+      return null;
+    }
+  }
+
+  // CHECK-START: java.lang.Object Main.noBoundTypeForIf(java.lang.Object) reference_type_propagation (after)
+  // CHECK-NOT: BoundType
+  public static Object noBoundTypeForIf(Object a) {
+    if (a == null) {
+      return new Object();
+    } else {
+      return null;
+    }
+  }
+
+  // CHECK-START: java.lang.Object Main.noBoundTypeForInstanceOf(java.lang.Object) reference_type_propagation (after)
+  // CHECK-NOT: BoundType
+  public static Object noBoundTypeForInstanceOf(Object a) {
+    if (a instanceof Main) {
+      return new Object();
+    } else {
+      return null;
+    }
+  }
+
+  public static void main(String[] args) {  }
+}