jni: Add read barrier fast path to jni compiler
Static method dispatch via JNI requires a read barrier
for the ArtMethod::GetDeclaringClass() load before adding it to the
JNI StackHandleScope.
We used to call ReadBarrierJni unconditionally but add a branch
to skip calling it if the GC is not currently in the marking phase.
Test: ART_USE_READ_BARRIER=true make test-art-host test-art-target
Bug: 30437917
Change-Id: I4f505ebde17c0a67209c7bb51b3f39e37a06373a
diff --git a/compiler/utils/arm64/jni_macro_assembler_arm64.cc b/compiler/utils/arm64/jni_macro_assembler_arm64.cc
index dfdcd11..9cd6884 100644
--- a/compiler/utils/arm64/jni_macro_assembler_arm64.cc
+++ b/compiler/utils/arm64/jni_macro_assembler_arm64.cc
@@ -262,9 +262,12 @@
___ Ldr(reg_w(dest.AsWRegister()), MEM_OP(reg_x(base), offset));
} else if (dest.IsXRegister()) {
CHECK_NE(dest.AsXRegister(), SP) << dest;
- if (size == 4u) {
+
+ if (size == 1u) {
+ ___ Ldrb(reg_w(dest.AsOverlappingWRegister()), MEM_OP(reg_x(base), offset));
+ } else if (size == 4u) {
___ Ldr(reg_w(dest.AsOverlappingWRegister()), MEM_OP(reg_x(base), offset));
- } else {
+ } else {
CHECK_EQ(8u, size) << dest;
___ Ldr(reg_x(dest.AsXRegister()), MEM_OP(reg_x(base), offset));
}
@@ -627,6 +630,38 @@
___ Cbnz(reg_x(scratch.AsXRegister()), exception_blocks_.back()->Entry());
}
+std::unique_ptr<JNIMacroLabel> Arm64JNIMacroAssembler::CreateLabel() {
+ return std::unique_ptr<JNIMacroLabel>(new Arm64JNIMacroLabel());
+}
+
+void Arm64JNIMacroAssembler::Jump(JNIMacroLabel* label) {
+ CHECK(label != nullptr);
+ ___ B(Arm64JNIMacroLabel::Cast(label)->AsArm64());
+}
+
+void Arm64JNIMacroAssembler::Jump(JNIMacroLabel* label,
+ JNIMacroUnaryCondition condition,
+ ManagedRegister test) {
+ CHECK(label != nullptr);
+
+ switch (condition) {
+ case JNIMacroUnaryCondition::kZero:
+ ___ Cbz(reg_x(test.AsArm64().AsXRegister()), Arm64JNIMacroLabel::Cast(label)->AsArm64());
+ break;
+ case JNIMacroUnaryCondition::kNotZero:
+ ___ Cbnz(reg_x(test.AsArm64().AsXRegister()), Arm64JNIMacroLabel::Cast(label)->AsArm64());
+ break;
+ default:
+ LOG(FATAL) << "Not implemented unary condition: " << static_cast<int>(condition);
+ UNREACHABLE();
+ }
+}
+
+void Arm64JNIMacroAssembler::Bind(JNIMacroLabel* label) {
+ CHECK(label != nullptr);
+ ___ Bind(Arm64JNIMacroLabel::Cast(label)->AsArm64());
+}
+
void Arm64JNIMacroAssembler::EmitExceptionPoll(Arm64Exception *exception) {
UseScratchRegisterScope temps(asm_.GetVIXLAssembler());
temps.Exclude(reg_x(exception->scratch_.AsXRegister()));
diff --git a/compiler/utils/arm64/jni_macro_assembler_arm64.h b/compiler/utils/arm64/jni_macro_assembler_arm64.h
index b9f6854..264e99a 100644
--- a/compiler/utils/arm64/jni_macro_assembler_arm64.h
+++ b/compiler/utils/arm64/jni_macro_assembler_arm64.h
@@ -168,6 +168,15 @@
// and branch to a ExceptionSlowPath if it is.
void ExceptionPoll(ManagedRegister scratch, size_t stack_adjust) OVERRIDE;
+ // Create a new label that can be used with Jump/Bind calls.
+ std::unique_ptr<JNIMacroLabel> CreateLabel() OVERRIDE;
+ // Emit an unconditional jump to the label.
+ void Jump(JNIMacroLabel* label) OVERRIDE;
+ // Emit a conditional jump to the label by applying a unary condition test to the register.
+ void Jump(JNIMacroLabel* label, JNIMacroUnaryCondition cond, ManagedRegister test) OVERRIDE;
+ // Code at this offset will serve as the target for the Jump call.
+ void Bind(JNIMacroLabel* label) OVERRIDE;
+
private:
class Arm64Exception {
public:
@@ -222,6 +231,16 @@
ArenaVector<std::unique_ptr<Arm64Exception>> exception_blocks_;
};
+class Arm64JNIMacroLabel FINAL
+ : public JNIMacroLabelCommon<Arm64JNIMacroLabel,
+ vixl::aarch64::Label,
+ kArm64> {
+ public:
+ vixl::aarch64::Label* AsArm64() {
+ return AsPlatformLabel();
+ }
+};
+
} // namespace arm64
} // namespace art