Use dominance information for null optimization in write barrier.
Change-Id: I8b57dafcd321c9afa1bbfc6a0674cbea15cbf10c
diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index d05c514..2c6c3b7 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -374,6 +374,11 @@
<< instance_of->MustDoNullCheck() << std::noboolalpha;
}
+ void VisitArraySet(HArraySet* array_set) OVERRIDE {
+ StartAttributeStream("value_can_be_null") << std::boolalpha
+ << array_set->GetValueCanBeNull() << std::noboolalpha;
+ }
+
void VisitInvoke(HInvoke* invoke) OVERRIDE {
StartAttributeStream("dex_file_index") << invoke->GetDexMethodIndex();
StartAttributeStream("method_name") << PrettyMethod(
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 0ac26de..30dc9b3 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -71,7 +71,8 @@
void VisitXor(HXor* instruction) OVERRIDE;
void VisitInstanceOf(HInstanceOf* instruction) OVERRIDE;
void VisitFakeString(HFakeString* fake_string) OVERRIDE;
- bool IsDominatedByInputNullCheck(HInstruction* instr);
+
+ bool CanEnsureNotNullAt(HInstruction* instr, HInstruction* at) const;
OptimizingCompilerStats* stats_;
bool simplification_occurred_ = false;
@@ -187,14 +188,18 @@
}
}
-bool InstructionSimplifierVisitor::IsDominatedByInputNullCheck(HInstruction* instr) {
- HInstruction* input = instr->InputAt(0);
+bool InstructionSimplifierVisitor::CanEnsureNotNullAt(HInstruction* input, HInstruction* at) const {
+ if (!input->CanBeNull()) {
+ return true;
+ }
+
for (HUseIterator<HInstruction*> it(input->GetUses()); !it.Done(); it.Advance()) {
HInstruction* use = it.Current()->GetUser();
- if (use->IsNullCheck() && use->StrictlyDominates(instr)) {
+ if (use->IsNullCheck() && use->StrictlyDominates(at)) {
return true;
}
}
+
return false;
}
@@ -231,7 +236,7 @@
void InstructionSimplifierVisitor::VisitCheckCast(HCheckCast* check_cast) {
HInstruction* object = check_cast->InputAt(0);
- if (!object->CanBeNull() || IsDominatedByInputNullCheck(check_cast)) {
+ if (CanEnsureNotNullAt(object, check_cast)) {
check_cast->ClearMustDoNullCheck();
}
@@ -267,7 +272,7 @@
void InstructionSimplifierVisitor::VisitInstanceOf(HInstanceOf* instruction) {
HInstruction* object = instruction->InputAt(0);
bool can_be_null = true;
- if (!object->CanBeNull() || IsDominatedByInputNullCheck(instruction)) {
+ if (CanEnsureNotNullAt(object, instruction)) {
can_be_null = false;
instruction->ClearMustDoNullCheck();
}
@@ -305,14 +310,14 @@
void InstructionSimplifierVisitor::VisitInstanceFieldSet(HInstanceFieldSet* instruction) {
if ((instruction->GetValue()->GetType() == Primitive::kPrimNot)
- && !instruction->GetValue()->CanBeNull()) {
+ && CanEnsureNotNullAt(instruction->GetValue(), instruction)) {
instruction->ClearValueCanBeNull();
}
}
void InstructionSimplifierVisitor::VisitStaticFieldSet(HStaticFieldSet* instruction) {
if ((instruction->GetValue()->GetType() == Primitive::kPrimNot)
- && !instruction->GetValue()->CanBeNull()) {
+ && CanEnsureNotNullAt(instruction->GetValue(), instruction)) {
instruction->ClearValueCanBeNull();
}
}
@@ -437,7 +442,7 @@
instruction->ClearNeedsTypeCheck();
}
- if (!value->CanBeNull()) {
+ if (CanEnsureNotNullAt(value, instruction)) {
instruction->ClearValueCanBeNull();
}
}
diff --git a/test/532-checker-nonnull-arrayset/expected.txt b/test/532-checker-nonnull-arrayset/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/532-checker-nonnull-arrayset/expected.txt
diff --git a/test/532-checker-nonnull-arrayset/info.txt b/test/532-checker-nonnull-arrayset/info.txt
new file mode 100644
index 0000000..e1578c8
--- /dev/null
+++ b/test/532-checker-nonnull-arrayset/info.txt
@@ -0,0 +1 @@
+Test that we optimize ArraySet when the value is not null.
diff --git a/test/532-checker-nonnull-arrayset/src/Main.java b/test/532-checker-nonnull-arrayset/src/Main.java
new file mode 100644
index 0000000..7d8fff4
--- /dev/null
+++ b/test/532-checker-nonnull-arrayset/src/Main.java
@@ -0,0 +1,39 @@
+/*
+ * 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 that we don't put a null check in the card marking code.
+
+ /// CHECK-START: void Main.test() instruction_simplifier (before)
+ /// CHECK: ArraySet value_can_be_null:true
+
+ /// CHECK-START: void Main.test() instruction_simplifier (after)
+ /// CHECK: ArraySet value_can_be_null:false
+
+ /// CHECK-START-X86: void Main.test() disassembly (after)
+ /// CHECK: ArraySet value_can_be_null:false
+ /// CHECK-NOT: test
+ /// CHECK: ReturnVoid
+ public static void test() {
+ Object[] array = new Object[1];
+ Object nonNull = array[0];
+ nonNull.getClass(); // Ensure nonNull has an implicit null check.
+ array[0] = nonNull;
+ }
+
+ public static void main(String[] args) {}
+}
