optimizing: NullCheck elimination
How it works:
- run a type analysis to propagate null information on instructions
- during the last instruction simplifier remove null checks for which
the input is known to be not null
The current type analysis is actually a nullability analysis but it will
be reused in follow up CLs to propagate type information: so it keeps
the more convenient name.
Change-Id: I54bb1d32ab24604b4d677d1ecdaf8d60a5ff5ce9
diff --git a/test/444-checker-nce/expected.txt b/test/444-checker-nce/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/444-checker-nce/expected.txt
diff --git a/test/444-checker-nce/info.txt b/test/444-checker-nce/info.txt
new file mode 100644
index 0000000..78ad0b9
--- /dev/null
+++ b/test/444-checker-nce/info.txt
@@ -0,0 +1 @@
+Tests for NullCheck elimination.
diff --git a/test/444-checker-nce/src/Main.java b/test/444-checker-nce/src/Main.java
new file mode 100644
index 0000000..cdca332
--- /dev/null
+++ b/test/444-checker-nce/src/Main.java
@@ -0,0 +1,229 @@
+/*
+ * 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: Main Main.keepTest(Main) instruction_simplifier_after_types (before)
+ // CHECK: NullCheck
+ // CHECK: InvokeStaticOrDirect
+
+ // CHECK-START: Main Main.keepTest(Main) instruction_simplifier_after_types (after)
+ // CHECK: NullCheck
+ // CHECK: InvokeStaticOrDirect
+ public Main keepTest(Main m) {
+ return m.g();
+ }
+
+ // CHECK-START: Main Main.thisTest() instruction_simplifier (before)
+ // CHECK: NullCheck
+ // CHECK: InvokeStaticOrDirect
+
+ // CHECK-START: Main Main.thisTest() instruction_simplifier (after)
+ // CHECK-NOT: NullCheck
+ // CHECK: InvokeStaticOrDirect
+ public Main thisTest() {
+ return g();
+ }
+
+ // CHECK-START: Main Main.newInstanceRemoveTest() instruction_simplifier (before)
+ // CHECK-DAG: NewInstance
+ // CHECK-DAG: NullCheck
+ // CHECK-DAG: InvokeStaticOrDirect
+ // CHECK-DAG: NullCheck
+ // CHECK-DAG: InvokeStaticOrDirect
+
+ // CHECK-START: Main Main.newInstanceRemoveTest() instruction_simplifier (after)
+ // CHECK-NOT: NullCheck
+ public Main newInstanceRemoveTest() {
+ Main m = new Main();
+ return m.g();
+ }
+
+ // CHECK-START: Main Main.newArrayRemoveTest() instruction_simplifier (before)
+ // CHECK-DAG: NewArray
+ // CHECK-DAG: NullCheck
+ // CHECK-DAG: ArrayGet
+
+ // CHECK-START: Main Main.newArrayRemoveTest() instruction_simplifier (after)
+ // CHECK-DAG: NewArray
+ // CHECK-NOT: NullCheck
+ // CHECK-DAG: ArrayGet
+ public Main newArrayRemoveTest() {
+ Main[] ms = new Main[1];
+ return ms[0];
+ }
+
+ // CHECK-START: Main Main.ifRemoveTest(boolean) instruction_simplifier_after_types (before)
+ // CHECK-DAG: NewInstance
+ // CHECK-DAG: NullCheck
+
+ // CHECK-START: Main Main.ifRemoveTest(boolean) instruction_simplifier_after_types (after)
+ // CHECK-DAG: NewInstance
+ // CHECK-NOT: NullCheck
+ public Main ifRemoveTest(boolean flag) {
+ Main m = null;
+ if (flag) {
+ m = new Main();
+ } else {
+ m = new Main(1);
+ }
+ return m.g();
+ }
+
+ // CHECK-START: Main Main.ifKeepTest(boolean) instruction_simplifier_after_types (before)
+ // CHECK-DAG: NewInstance
+ // CHECK-DAG: NullCheck
+
+ // CHECK-START: Main Main.ifKeepTest(boolean) instruction_simplifier_after_types (after)
+ // CHECK-DAG: NewInstance
+ // CHECK-DAG: NullCheck
+ public Main ifKeepTest(boolean flag) {
+ Main m = null;
+ if (flag) {
+ m = new Main(1);
+ }
+ return m.g();
+ }
+
+ // CHECK-START: Main Main.forRemoveTest(int) instruction_simplifier_after_types (before)
+ // CHECK: NullCheck
+
+ // CHECK-START: Main Main.forRemoveTest(int) instruction_simplifier_after_types (after)
+ // CHECK-NOT: NullCheck
+ public Main forRemoveTest(int count) {
+ Main a = new Main();
+ Main m = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 2 == 0) {
+ m = a;
+ }
+ }
+ return m.g();
+ }
+
+ // CHECK-START: Main Main.forKeepTest(int) instruction_simplifier_after_types (before)
+ // CHECK: NullCheck
+
+ // CHECK-START: Main Main.forKeepTest(int) instruction_simplifier_after_types (after)
+ // CHECK: NullCheck
+ public Main forKeepTest(int count) {
+ Main a = new Main();
+ Main m = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 2 == 0) {
+ m = a;
+ } else {
+ m = null;
+ }
+ }
+ return m.g();
+ }
+
+ // CHECK-START: Main Main.phiFlowRemoveTest(int) instruction_simplifier_after_types (before)
+ // CHECK: NullCheck
+
+ // CHECK-START: Main Main.phiFlowRemoveTest(int) instruction_simplifier_after_types (after)
+ // CHECK-NOT: NullCheck
+ public Main phiFlowRemoveTest(int count) {
+ Main a = new Main();
+ Main m = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 2 == 0) {
+ m = a;
+ }
+ }
+ Main n = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 3 == 0) {
+ n = m;
+ }
+ }
+ return n.g();
+ }
+
+ // CHECK-START: Main Main.phiFlowKeepTest(int) instruction_simplifier_after_types (before)
+ // CHECK: NullCheck
+
+ // CHECK-START: Main Main.phiFlowKeepTest(int) instruction_simplifier_after_types (after)
+ // CHECK: NullCheck
+ public Main phiFlowKeepTest(int count) {
+ Main a = new Main();
+ Main m = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 2 == 0) {
+ m = a;
+ } else {
+ m = null;
+ }
+ }
+ Main n = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 3 == 0) {
+ n = m;
+ }
+ }
+ return n.g();
+ }
+
+ // CHECK-START: Main Main.scopeRemoveTest(int, Main) instruction_simplifier (before)
+ // CHECK: NullCheck
+
+ // CHECK-START: Main Main.scopeRemoveTest(int, Main) instruction_simplifier (after)
+ // CHECK-NOT: NullCheck
+ public Main scopeRemoveTest(int count, Main a) {
+ Main m = null;
+ for (int i = 0; i < count; i++) {
+ if (i % 2 == 0) {
+ m = new Main();
+ m.g();
+ } else {
+ m = a;
+ }
+ }
+ return m;
+ }
+
+ // CHECK-START: Main Main.scopeKeepTest(int, Main) instruction_simplifier_after_types (before)
+ // CHECK: NullCheck
+
+ // CHECK-START: Main Main.scopeKeepTest(int, Main) instruction_simplifier_after_types (after)
+ // CHECK: NullCheck
+ public Main scopeKeepTest(int count, Main a) {
+ Main m = new Main();
+ for (int i = 0; i < count; i++) {
+ if (i % 2 == 0) {
+ m = a;
+ } else {
+ m = a;
+ m.g();
+ }
+ }
+ return m;
+ }
+
+ public Main() {}
+ public Main(int dummy) {}
+
+ private Main g() {
+ // avoids inlining
+ throw new RuntimeException();
+ }
+
+ public static void main(String[] args) {
+ new Main();
+ }
+
+}