Fix String.equals() for moveable String.class.
If the String.class is moveable (i.e. running without boot
image), the instanceof check emitted by the JIT in the
String.equals() intrinsic would require read barriers.
As we do not really care about the performance of running
without the boot image, disable the intrinsic in this case.
Test: 669-moveable-string-class-equals (--jit)
Bug: 68181300
Change-Id: I39c9f9935e0482b3b30f1ae5cd23515cbda0603b
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 2bd2d5f..fbfee12 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -2024,6 +2024,20 @@
ReferenceTypeInfo argument_rti = argument->GetReferenceTypeInfo();
if (argument_rti.IsValid() && argument_rti.IsStringClass()) {
optimizations.SetArgumentIsString();
+ } else if (kUseReadBarrier) {
+ DCHECK(instruction->GetResolvedMethod() != nullptr);
+ DCHECK(instruction->GetResolvedMethod()->GetDeclaringClass()->IsStringClass());
+ Runtime* runtime = Runtime::Current();
+ // For AOT, we always assume that the boot image shall contain the String.class and
+ // we do not need a read barrier for boot image classes as they are non-moveable.
+ // For JIT, check if we actually have a boot image; if we do, the String.class
+ // should also be non-moveable.
+ if (runtime->IsAotCompiler() || runtime->GetHeap()->HasBootImageSpace()) {
+ DCHECK(runtime->IsAotCompiler() ||
+ !runtime->GetHeap()->IsMovableObject(
+ instruction->GetResolvedMethod()->GetDeclaringClass()));
+ optimizations.SetNoReadBarrierForStringClass();
+ }
}
}
}
diff --git a/compiler/optimizing/intrinsics.h b/compiler/optimizing/intrinsics.h
index bdeb261..707ff34 100644
--- a/compiler/optimizing/intrinsics.h
+++ b/compiler/optimizing/intrinsics.h
@@ -203,6 +203,7 @@
INTRINSIC_OPTIMIZATION(ArgumentNotNull, 0);
INTRINSIC_OPTIMIZATION(ArgumentIsString, 1);
+ INTRINSIC_OPTIMIZATION(NoReadBarrierForStringClass, 2);
private:
DISALLOW_COPY_AND_ASSIGN(StringEqualsOptimizations);
diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc
index ef85f9c..ca1b451 100644
--- a/compiler/optimizing/intrinsics_arm64.cc
+++ b/compiler/optimizing/intrinsics_arm64.cc
@@ -1519,6 +1519,13 @@
}
void IntrinsicLocationsBuilderARM64::VisitStringEquals(HInvoke* invoke) {
+ if (kEmitCompilerReadBarrier &&
+ !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+ !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+ // No support for this odd case (String class is moveable, not in the boot image).
+ return;
+ }
+
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
diff --git a/compiler/optimizing/intrinsics_arm_vixl.cc b/compiler/optimizing/intrinsics_arm_vixl.cc
index e0874d9..1d8ea09 100644
--- a/compiler/optimizing/intrinsics_arm_vixl.cc
+++ b/compiler/optimizing/intrinsics_arm_vixl.cc
@@ -1723,6 +1723,13 @@
}
void IntrinsicLocationsBuilderARMVIXL::VisitStringEquals(HInvoke* invoke) {
+ if (kEmitCompilerReadBarrier &&
+ !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+ !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+ // No support for this odd case (String class is moveable, not in the boot image).
+ return;
+ }
+
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
InvokeRuntimeCallingConventionARMVIXL calling_convention;
diff --git a/compiler/optimizing/intrinsics_mips.cc b/compiler/optimizing/intrinsics_mips.cc
index 4a8fbf2..140526a 100644
--- a/compiler/optimizing/intrinsics_mips.cc
+++ b/compiler/optimizing/intrinsics_mips.cc
@@ -2062,6 +2062,13 @@
// boolean java.lang.String.equals(Object anObject)
void IntrinsicLocationsBuilderMIPS::VisitStringEquals(HInvoke* invoke) {
+ if (kEmitCompilerReadBarrier &&
+ !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+ !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+ // No support for this odd case (String class is moveable, not in the boot image).
+ return;
+ }
+
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
diff --git a/compiler/optimizing/intrinsics_mips64.cc b/compiler/optimizing/intrinsics_mips64.cc
index 512fb68..a58ff7c 100644
--- a/compiler/optimizing/intrinsics_mips64.cc
+++ b/compiler/optimizing/intrinsics_mips64.cc
@@ -1637,6 +1637,13 @@
// boolean java.lang.String.equals(Object anObject)
void IntrinsicLocationsBuilderMIPS64::VisitStringEquals(HInvoke* invoke) {
+ if (kEmitCompilerReadBarrier &&
+ !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+ !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+ // No support for this odd case (String class is moveable, not in the boot image).
+ return;
+ }
+
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
diff --git a/compiler/optimizing/intrinsics_x86.cc b/compiler/optimizing/intrinsics_x86.cc
index 8a0b6ae..baa410b 100644
--- a/compiler/optimizing/intrinsics_x86.cc
+++ b/compiler/optimizing/intrinsics_x86.cc
@@ -1345,6 +1345,13 @@
}
void IntrinsicLocationsBuilderX86::VisitStringEquals(HInvoke* invoke) {
+ if (kEmitCompilerReadBarrier &&
+ !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+ !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+ // No support for this odd case (String class is moveable, not in the boot image).
+ return;
+ }
+
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());
diff --git a/compiler/optimizing/intrinsics_x86_64.cc b/compiler/optimizing/intrinsics_x86_64.cc
index 92ffda4..6dd8b8e 100644
--- a/compiler/optimizing/intrinsics_x86_64.cc
+++ b/compiler/optimizing/intrinsics_x86_64.cc
@@ -1520,6 +1520,13 @@
}
void IntrinsicLocationsBuilderX86_64::VisitStringEquals(HInvoke* invoke) {
+ if (kEmitCompilerReadBarrier &&
+ !StringEqualsOptimizations(invoke).GetArgumentIsString() &&
+ !StringEqualsOptimizations(invoke).GetNoReadBarrierForStringClass()) {
+ // No support for this odd case (String class is moveable, not in the boot image).
+ return;
+ }
+
LocationSummary* locations =
new (allocator_) LocationSummary(invoke, LocationSummary::kNoCall, kIntrinsified);
locations->SetInAt(0, Location::RequiresRegister());