Enable store elimination for singleton objects.
Enable store elimination for singleton objects. However for finalizable object,
don't eliminate stores. Also added a testcase.
Change-Id: Icf991e7ded5b490f55f580ef928ece5c45e89902
diff --git a/compiler/dex/quick/gen_common.cc b/compiler/dex/quick/gen_common.cc
index 2b60a51..5da7214 100644
--- a/compiler/dex/quick/gen_common.cc
+++ b/compiler/dex/quick/gen_common.cc
@@ -1104,7 +1104,11 @@
// access because the verifier was unable to?
const DexFile* dex_file = cu_->dex_file;
CompilerDriver* driver = cu_->compiler_driver;
- if (driver->CanAccessInstantiableTypeWithoutChecks(cu_->method_idx, *dex_file, type_idx)) {
+ bool finalizable;
+ if (driver->CanAccessInstantiableTypeWithoutChecks(cu_->method_idx,
+ *dex_file,
+ type_idx,
+ &finalizable)) {
bool is_type_initialized;
bool use_direct_type_ptr;
uintptr_t direct_type_ptr;
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 8750aa8..fa3598e 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -1247,7 +1247,8 @@
bool CompilerDriver::CanAccessInstantiableTypeWithoutChecks(uint32_t referrer_idx,
const DexFile& dex_file,
- uint32_t type_idx) {
+ uint32_t type_idx,
+ bool* finalizable) {
ScopedObjectAccess soa(Thread::Current());
mirror::DexCache* dex_cache = Runtime::Current()->GetClassLinker()->FindDexCache(
soa.Self(), dex_file, false);
@@ -1255,8 +1256,11 @@
mirror::Class* resolved_class = dex_cache->GetResolvedType(type_idx);
if (resolved_class == nullptr) {
stats_->TypeNeedsAccessCheck();
+ // Be conservative.
+ *finalizable = true;
return false; // Unknown class needs access checks.
}
+ *finalizable = resolved_class->IsFinalizable();
const DexFile::MethodId& method_id = dex_file.GetMethodId(referrer_idx);
mirror::Class* referrer_class = dex_cache->GetResolvedType(method_id.class_idx_);
if (referrer_class == nullptr) {
diff --git a/compiler/driver/compiler_driver.h b/compiler/driver/compiler_driver.h
index 485cdcf..15806b5 100644
--- a/compiler/driver/compiler_driver.h
+++ b/compiler/driver/compiler_driver.h
@@ -200,8 +200,10 @@
REQUIRES(!Locks::mutator_lock_);
// Are runtime access and instantiable checks necessary in the code?
- bool CanAccessInstantiableTypeWithoutChecks(uint32_t referrer_idx, const DexFile& dex_file,
- uint32_t type_idx)
+ bool CanAccessInstantiableTypeWithoutChecks(uint32_t referrer_idx,
+ const DexFile& dex_file,
+ uint32_t type_idx,
+ bool* finalizable)
REQUIRES(!Locks::mutator_lock_);
bool CanEmbedTypeInCode(const DexFile& dex_file, uint32_t type_idx,
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index ed193c7..ee5b929 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -1455,7 +1455,8 @@
uint32_t* args,
uint32_t register_index) {
HInstruction* length = graph_->GetIntConstant(number_of_vreg_arguments, dex_pc);
- QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index)
+ bool finalizable;
+ QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index, &finalizable)
? kQuickAllocArrayWithAccessCheck
: kQuickAllocArray;
HInstruction* object = new (arena_) HNewArray(length,
@@ -1635,9 +1636,9 @@
}
}
-bool HGraphBuilder::NeedsAccessCheck(uint32_t type_index) const {
+bool HGraphBuilder::NeedsAccessCheck(uint32_t type_index, bool* finalizable) const {
return !compiler_driver_->CanAccessInstantiableTypeWithoutChecks(
- dex_compilation_unit_->GetDexMethodIndex(), *dex_file_, type_index);
+ dex_compilation_unit_->GetDexMethodIndex(), *dex_file_, type_index, finalizable);
}
void HGraphBuilder::BuildSwitchJumpTable(const SwitchTable& table,
@@ -2514,7 +2515,9 @@
current_block_->AddInstruction(fake_string);
UpdateLocal(register_index, fake_string, dex_pc);
} else {
- QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index)
+ bool finalizable;
+ bool can_throw = NeedsAccessCheck(type_index, &finalizable);
+ QuickEntrypointEnum entrypoint = can_throw
? kQuickAllocObjectWithAccessCheck
: kQuickAllocObject;
@@ -2523,6 +2526,8 @@
dex_pc,
type_index,
*dex_compilation_unit_->GetDexFile(),
+ can_throw,
+ finalizable,
entrypoint));
UpdateLocal(instruction.VRegA(), current_block_->GetLastInstruction(), dex_pc);
}
@@ -2532,7 +2537,8 @@
case Instruction::NEW_ARRAY: {
uint16_t type_index = instruction.VRegC_22c();
HInstruction* length = LoadLocal(instruction.VRegB_22c(), Primitive::kPrimInt, dex_pc);
- QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index)
+ bool finalizable;
+ QuickEntrypointEnum entrypoint = NeedsAccessCheck(type_index, &finalizable)
? kQuickAllocArrayWithAccessCheck
: kQuickAllocArray;
current_block_->AddInstruction(new (arena_) HNewArray(length,
diff --git a/compiler/optimizing/builder.h b/compiler/optimizing/builder.h
index 9eaa4b6..0f64489 100644
--- a/compiler/optimizing/builder.h
+++ b/compiler/optimizing/builder.h
@@ -138,7 +138,7 @@
HInstruction* LoadLocal(uint32_t register_index, Primitive::Type type, uint32_t dex_pc) const;
void PotentiallyAddSuspendCheck(HBasicBlock* target, uint32_t dex_pc);
void InitializeParameters(uint16_t number_of_parameters);
- bool NeedsAccessCheck(uint32_t type_index) const;
+ bool NeedsAccessCheck(uint32_t type_index, bool* finalizable) const;
template<typename T>
void Unop_12x(const Instruction& instruction, Primitive::Type type, uint32_t dex_pc);
diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index 90f28e5..aa9c315 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -695,8 +695,12 @@
} else {
redundant_store = true;
}
- // TODO: eliminate the store if the singleton object is not finalizable.
- redundant_store = false;
+ HNewInstance* new_instance = ref_info->GetReference()->AsNewInstance();
+ DCHECK(new_instance != nullptr);
+ if (new_instance->IsFinalizable()) {
+ // Finalizable objects escape globally. Need to keep the store.
+ redundant_store = false;
+ }
}
if (redundant_store) {
removed_instructions_.push_back(instruction);
@@ -834,7 +838,9 @@
return;
}
if (!heap_location_collector_.MayDeoptimize() &&
- ref_info->IsSingletonAndNotReturned()) {
+ ref_info->IsSingletonAndNotReturned() &&
+ !new_instance->IsFinalizable() &&
+ !new_instance->CanThrow()) {
// The allocation might be eliminated.
singleton_new_instances_.push_back(new_instance);
}
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 6028d4b..7ac39d1 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -3595,10 +3595,14 @@
uint32_t dex_pc,
uint16_t type_index,
const DexFile& dex_file,
+ bool can_throw,
+ bool finalizable,
QuickEntrypointEnum entrypoint)
: HExpression(Primitive::kPrimNot, SideEffects::CanTriggerGC(), dex_pc),
type_index_(type_index),
dex_file_(dex_file),
+ can_throw_(can_throw),
+ finalizable_(finalizable),
entrypoint_(entrypoint) {
SetRawInputAt(0, current_method);
}
@@ -3608,11 +3612,11 @@
// Calls runtime so needs an environment.
bool NeedsEnvironment() const OVERRIDE { return true; }
- // It may throw when called on:
- // - interfaces
- // - abstract/innaccessible/unknown classes
- // TODO: optimize when possible.
- bool CanThrow() const OVERRIDE { return true; }
+
+ // It may throw when called on type that's not instantiable/accessible.
+ bool CanThrow() const OVERRIDE { return can_throw_; }
+
+ bool IsFinalizable() const { return finalizable_; }
bool CanBeNull() const OVERRIDE { return false; }
@@ -3623,6 +3627,8 @@
private:
const uint16_t type_index_;
const DexFile& dex_file_;
+ const bool can_throw_;
+ const bool finalizable_;
const QuickEntrypointEnum entrypoint_;
DISALLOW_COPY_AND_ASSIGN(HNewInstance);
diff --git a/test/530-checker-lse/src/Main.java b/test/530-checker-lse/src/Main.java
index c766aaa..924ff67 100644
--- a/test/530-checker-lse/src/Main.java
+++ b/test/530-checker-lse/src/Main.java
@@ -22,7 +22,7 @@
return radius * radius * Math.PI;
}
private double radius;
-};
+}
class TestClass {
TestClass() {
@@ -36,16 +36,29 @@
volatile int k;
TestClass next;
static int si;
-};
+}
class SubTestClass extends TestClass {
int k;
-};
+}
class TestClass2 {
int i;
int j;
-};
+}
+
+class Finalizable {
+ static boolean sVisited = false;
+ static final int VALUE = 0xbeef;
+ int i;
+
+ protected void finalize() {
+ if (i != VALUE) {
+ System.out.println("Where is the beef?");
+ }
+ sVisited = true;
+ }
+}
public class Main {
@@ -56,7 +69,7 @@
/// CHECK-START: double Main.calcCircleArea(double) load_store_elimination (after)
/// CHECK: NewInstance
- /// CHECK: InstanceFieldSet
+ /// CHECK-NOT: InstanceFieldSet
/// CHECK-NOT: InstanceFieldGet
static double calcCircleArea(double radius) {
@@ -117,7 +130,7 @@
/// CHECK: InstanceFieldGet
/// CHECK: InstanceFieldSet
/// CHECK: NewInstance
- /// CHECK: InstanceFieldSet
+ /// CHECK-NOT: InstanceFieldSet
/// CHECK-NOT: InstanceFieldGet
// A new allocation shouldn't alias with pre-existing values.
@@ -223,7 +236,7 @@
/// CHECK-START: int Main.test8() load_store_elimination (after)
/// CHECK: NewInstance
- /// CHECK: InstanceFieldSet
+ /// CHECK-NOT: InstanceFieldSet
/// CHECK: InvokeVirtual
/// CHECK-NOT: NullCheck
/// CHECK-NOT: InstanceFieldGet
@@ -381,8 +394,8 @@
/// CHECK-START: int Main.test16() load_store_elimination (after)
/// CHECK: NewInstance
- /// CHECK-NOT: StaticFieldSet
- /// CHECK-NOT: StaticFieldGet
+ /// CHECK-NOT: InstanceFieldSet
+ /// CHECK-NOT: InstanceFieldGet
// Test inlined constructor.
static int test16() {
@@ -398,8 +411,8 @@
/// CHECK-START: int Main.test17() load_store_elimination (after)
/// CHECK: <<Const0:i\d+>> IntConstant 0
/// CHECK: NewInstance
- /// CHECK-NOT: StaticFieldSet
- /// CHECK-NOT: StaticFieldGet
+ /// CHECK-NOT: InstanceFieldSet
+ /// CHECK-NOT: InstanceFieldGet
/// CHECK: Return [<<Const0>>]
// Test getting default value.
@@ -455,6 +468,55 @@
return obj;
}
+ /// CHECK-START: void Main.testFinalizable() load_store_elimination (before)
+ /// CHECK: NewInstance
+ /// CHECK: InstanceFieldSet
+
+ /// CHECK-START: void Main.testFinalizable() load_store_elimination (after)
+ /// CHECK: NewInstance
+ /// CHECK: InstanceFieldSet
+
+ // Allocations and stores into finalizable objects cannot be eliminated.
+ static void testFinalizable() {
+ Finalizable finalizable = new Finalizable();
+ finalizable.i = Finalizable.VALUE;
+ }
+
+ static java.lang.ref.WeakReference<Object> getWeakReference() {
+ return new java.lang.ref.WeakReference<>(new Object());
+ }
+
+ static void testFinalizableByForcingGc() {
+ testFinalizable();
+ java.lang.ref.WeakReference<Object> reference = getWeakReference();
+
+ Runtime runtime = Runtime.getRuntime();
+ for (int i = 0; i < 20; ++i) {
+ runtime.gc();
+ System.runFinalization();
+ try {
+ Thread.sleep(1);
+ } catch (InterruptedException e) {
+ throw new AssertionError(e);
+ }
+
+ // Check to see if the weak reference has been garbage collected.
+ if (reference.get() == null) {
+ // A little bit more sleep time to make sure.
+ try {
+ Thread.sleep(100);
+ } catch (InterruptedException e) {
+ throw new AssertionError(e);
+ }
+ if (!Finalizable.sVisited) {
+ System.out.println("finalize() not called.");
+ }
+ return;
+ }
+ }
+ System.out.println("testFinalizableByForcingGc() failed to force gc.");
+ }
+
public static void assertIntEquals(int expected, int result) {
if (expected != result) {
throw new Error("Expected: " + expected + ", found: " + result);
@@ -508,5 +570,6 @@
float[] fa2 = { 1.8f };
assertFloatEquals(test19(fa1, fa2), 1.8f);
assertFloatEquals(test20().i, 0);
+ testFinalizableByForcingGc();
}
}