Ensure object ArraySet with null value does not need a type check.
The art::PrepareForRegisterAllocation visitor can remove an
art::BoundType instruction as value input of an
art::ArraySet instruction, possibly replacing it with an
art::NullConstant. If this happens, remove the need for a
type check in this art::ArraySet.
Bug: 27638110
Change-Id: I6270f8a8e22822a24d8a5919df427ca9c64d121b
diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index 4f1e90c..3a9d242 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -382,6 +382,8 @@
void VisitArraySet(HArraySet* array_set) OVERRIDE {
StartAttributeStream("value_can_be_null") << std::boolalpha
<< array_set->GetValueCanBeNull() << std::noboolalpha;
+ StartAttributeStream("needs_type_check") << std::boolalpha
+ << array_set->NeedsTypeCheck() << std::noboolalpha;
}
void VisitCompare(HCompare* compare) OVERRIDE {
diff --git a/compiler/optimizing/prepare_for_register_allocation.cc b/compiler/optimizing/prepare_for_register_allocation.cc
index 0ad104e..fc72727 100644
--- a/compiler/optimizing/prepare_for_register_allocation.cc
+++ b/compiler/optimizing/prepare_for_register_allocation.cc
@@ -47,6 +47,19 @@
bound_type->GetBlock()->RemoveInstruction(bound_type);
}
+void PrepareForRegisterAllocation::VisitArraySet(HArraySet* instruction) {
+ HInstruction* value = instruction->GetValue();
+ // PrepareForRegisterAllocation::VisitBoundType may have replaced a
+ // BoundType (as value input of this ArraySet) with a NullConstant.
+ // If so, this ArraySet no longer needs a type check.
+ if (value->IsNullConstant()) {
+ DCHECK_EQ(value->GetType(), Primitive::kPrimNot);
+ if (instruction->NeedsTypeCheck()) {
+ instruction->ClearNeedsTypeCheck();
+ }
+ }
+}
+
void PrepareForRegisterAllocation::VisitClinitCheck(HClinitCheck* check) {
// Try to find a static invoke or a new-instance from which this check originated.
HInstruction* implicit_clinit = nullptr;
diff --git a/compiler/optimizing/prepare_for_register_allocation.h b/compiler/optimizing/prepare_for_register_allocation.h
index c90724c..a679148 100644
--- a/compiler/optimizing/prepare_for_register_allocation.h
+++ b/compiler/optimizing/prepare_for_register_allocation.h
@@ -40,6 +40,7 @@
void VisitDivZeroCheck(HDivZeroCheck* check) OVERRIDE;
void VisitBoundsCheck(HBoundsCheck* check) OVERRIDE;
void VisitBoundType(HBoundType* bound_type) OVERRIDE;
+ void VisitArraySet(HArraySet* instruction) OVERRIDE;
void VisitClinitCheck(HClinitCheck* check) OVERRIDE;
void VisitCondition(HCondition* condition) OVERRIDE;
void VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) OVERRIDE;
diff --git a/test/590-checker-array-set-null-regression/expected.txt b/test/590-checker-array-set-null-regression/expected.txt
new file mode 100644
index 0000000..b0aad4d
--- /dev/null
+++ b/test/590-checker-array-set-null-regression/expected.txt
@@ -0,0 +1 @@
+passed
diff --git a/test/590-checker-array-set-null-regression/info.txt b/test/590-checker-array-set-null-regression/info.txt
new file mode 100644
index 0000000..fe173a3
--- /dev/null
+++ b/test/590-checker-array-set-null-regression/info.txt
@@ -0,0 +1,11 @@
+Regression test for art::PrepareForRegisterAllocation, which replaces
+
+ ArraySet[array, index, BoundType[NullConstant]]
+
+with
+
+ ArraySet[array, index, NullConstant]
+
+but used to forget to remove the "need for a type check" bit in the
+ArraySet, thus failing "!may_need_runtime_call_for_type_check"
+assertions in code generators.
diff --git a/test/590-checker-array-set-null-regression/src/Main.java b/test/590-checker-array-set-null-regression/src/Main.java
new file mode 100644
index 0000000..792ee4e
--- /dev/null
+++ b/test/590-checker-array-set-null-regression/src/Main.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2016 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 {
+
+ public static void main(String args[]) {
+ Element[] elements = new Element[51];
+ testArraySetCheckCastNull(elements);
+
+ System.out.println("passed");
+ }
+
+ /// CHECK-START: void Main.testArraySetCheckCastNull(Main$Element[]) builder (after)
+ /// CHECK: <<Array:l\d+>> ParameterValue
+ /// CHECK-DAG: <<Index:i\d+>> IntConstant 42
+ /// CHECK-DAG: <<Null:l\d+>> NullConstant
+ /// CHECK-DAG: <<Class:l\d+>> LoadClass
+ /// CHECK-DAG: CheckCast [<<Null>>,<<Class>>]
+ /// CHECK-DAG: <<CheckedValue:l\d+>> BoundType [<<Null>>] klass:Main$Element can_be_null:true
+ /// CHECK-DAG: <<CheckedArray:l\d+>> NullCheck [<<Array>>]
+ /// CHECK-DAG: <<Length:i\d+>> ArrayLength [<<CheckedArray>>]
+ /// CHECK-DAG: <<CheckedIndex:i\d+>> BoundsCheck [<<Index>>,<<Length>>]
+ /// CHECK-DAG: <<ArraySet:v\d+>> ArraySet [<<CheckedArray>>,<<CheckedIndex>>,<<CheckedValue>>] needs_type_check:true
+
+ /// CHECK-START: void Main.testArraySetCheckCastNull(Main$Element[]) instruction_simplifier (after)
+ /// CHECK-NOT: CheckCast
+
+ /// CHECK-START: void Main.testArraySetCheckCastNull(Main$Element[]) prepare_for_register_allocation (before)
+ /// CHECK: <<Array:l\d+>> ParameterValue
+ /// CHECK-DAG: <<Index:i\d+>> IntConstant 42
+ /// CHECK-DAG: <<Null:l\d+>> NullConstant
+ /// CHECK-DAG: <<Class:l\d+>> LoadClass
+ /// CHECK-DAG: <<CheckedValue:l\d+>> BoundType [<<Null>>]
+ /// CHECK-DAG: <<CheckedArray:l\d+>> NullCheck [<<Array>>]
+ /// CHECK-DAG: <<Length:i\d+>> ArrayLength [<<CheckedArray>>]
+ /// CHECK-DAG: <<CheckedIndex:i\d+>> BoundsCheck [<<Index>>,<<Length>>]
+ /// CHECK-DAG: <<ArraySet:v\d+>> ArraySet [<<CheckedArray>>,<<CheckedIndex>>,<<CheckedValue>>] needs_type_check:true
+
+ /// CHECK-START: void Main.testArraySetCheckCastNull(Main$Element[]) prepare_for_register_allocation (after)
+ /// CHECK: <<Array:l\d+>> ParameterValue
+ /// CHECK-DAG: <<Index:i\d+>> IntConstant 42
+ /// CHECK-DAG: <<Null:l\d+>> NullConstant
+ /// CHECK-DAG: <<Class:l\d+>> LoadClass
+ /// CHECK-DAG: <<Length:i\d+>> ArrayLength [<<Array>>]
+ /// CHECK-DAG: <<ArraySet:v\d+>> ArraySet [<<Array>>,<<Index>>,<<Null>>] needs_type_check:false
+
+ static void testArraySetCheckCastNull(Element[] elements) {
+ Object object = null;
+ Element element = (Element) object;
+ elements[42] = element;
+ }
+
+ class Element {}
+
+}