Fix a bug in optimizing when the null constant has been DCE.
If it has been DCE, we should create a new one, instead of
using the old one.
Also move the first DCE to a place where it could actually
be useful.
bug:21870788
Change-Id: I28fc52ae481ef92cba45fc1b5abcf07c995f524c
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 4baa05c..830d84b 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -288,7 +288,10 @@
}
HNullConstant* HGraph::GetNullConstant() {
- if (cached_null_constant_ == nullptr) {
+ // For simplicity, don't bother reviving the cached null constant if it is
+ // not null and not in a block. Otherwise, we need to clear the instruction
+ // id and/or any invariants the graph is assuming when adding new instructions.
+ if ((cached_null_constant_ == nullptr) || (cached_null_constant_->GetBlock() == nullptr)) {
cached_null_constant_ = new (arena_) HNullConstant();
InsertConstant(cached_null_constant_);
}
diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index 303a7cb..c695abe 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -348,10 +348,10 @@
HOptimization* optimizations[] = {
intrinsics,
- dce1,
fold1,
simplify1,
type_propagation,
+ dce1,
simplify2,
inliner,
// Run another type propagation phase: inlining will open up more opprotunities
diff --git a/test/501-null-constant-dce/expected.txt b/test/501-null-constant-dce/expected.txt
new file mode 100644
index 0000000..ccaf6f8
--- /dev/null
+++ b/test/501-null-constant-dce/expected.txt
@@ -0,0 +1 @@
+Enter
diff --git a/test/501-null-constant-dce/info.txt b/test/501-null-constant-dce/info.txt
new file mode 100644
index 0000000..2c4a686
--- /dev/null
+++ b/test/501-null-constant-dce/info.txt
@@ -0,0 +1 @@
+Regression test for the optimizing compiler. See comment in smali file.
diff --git a/test/501-null-constant-dce/smali/DCE.smali b/test/501-null-constant-dce/smali/DCE.smali
new file mode 100644
index 0000000..4a1765e
--- /dev/null
+++ b/test/501-null-constant-dce/smali/DCE.smali
@@ -0,0 +1,37 @@
+# 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.
+
+.class public LDCE;
+
+.super Ljava/lang/Object;
+
+.method public static method([I)LDCE;
+ .registers 2
+ const/4 v0, 0
+ # Jump over the code that requires the null constant
+ # so that the compiler sees the null constant as dead code.
+ if-eq v0, v0, :end
+ invoke-static {v0}, LDCE;->method([I)LDCE;
+ :end
+ invoke-static {}, LDCE;->$inline$returnNull()LDCE;
+ move-result-object v0
+ return-object v0
+.end method
+
+.method public static $inline$returnNull()LDCE;
+ .registers 2
+ const/4 v0, 0
+ # Return null to make `method` call GetConstantNull again.
+ return-object v0
+.end method
diff --git a/test/501-null-constant-dce/src/Main.java b/test/501-null-constant-dce/src/Main.java
new file mode 100644
index 0000000..3a2d491
--- /dev/null
+++ b/test/501-null-constant-dce/src/Main.java
@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+
+import java.lang.reflect.Method;
+
+public class Main {
+ public static void main(String[] args) throws Exception {
+ // Workaround for b/18051191.
+ System.out.println("Enter");
+ Class<?> c = Class.forName("DCE");
+ Method m = c.getMethod("method", int[].class);
+ int[] array = new int[7];
+ Object[] arguments = { array };
+ Object result = m.invoke(null, arguments);
+ if (result != null) {
+ throw new Error("Expected null, got " + result);
+ }
+ }
+}
