/* * Copyright (C) 2019 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. */ /* * Mterp entry point and support functions. */ #include "nterp.h" #include "base/quasi_atomic.h" #include "class_linker-inl.h" #include "dex/dex_instruction_utils.h" #include "debugger.h" #include "entrypoints/entrypoint_utils-inl.h" #include "interpreter/interpreter_cache-inl.h" #include "interpreter/interpreter_common.h" #include "interpreter/interpreter_intrinsics.h" #include "interpreter/shadow_frame-inl.h" #include "mirror/string-alloc-inl.h" #include "nterp_helpers.h" namespace art { namespace interpreter { bool IsNterpSupported() { return !kPoisonHeapReferences && kUseReadBarrier; } bool CanRuntimeUseNterp() REQUIRES_SHARED(Locks::mutator_lock_) { Runtime* runtime = Runtime::Current(); instrumentation::Instrumentation* instr = runtime->GetInstrumentation(); // If the runtime is interpreter only, we currently don't use nterp as some // parts of the runtime (like instrumentation) make assumption on an // interpreter-only runtime to always be in a switch-like interpreter. return IsNterpSupported() && !instr->InterpretOnly() && !runtime->IsAotCompiler() && !runtime->GetInstrumentation()->NeedsSlowInterpreterForListeners() && // An async exception has been thrown. We need to go to the switch interpreter. nterp doesn't // know how to deal with these so we could end up never dealing with it if we are in an // infinite loop. !runtime->AreAsyncExceptionsThrown() && (runtime->GetJit() == nullptr || !runtime->GetJit()->JitAtFirstUse()); } // The entrypoint for nterp, which ArtMethods can directly point to. extern "C" void ExecuteNterpImpl() REQUIRES_SHARED(Locks::mutator_lock_); const void* GetNterpEntryPoint() { return reinterpret_cast(interpreter::ExecuteNterpImpl); } /* * Verify some constants used by the nterp interpreter. */ void CheckNterpAsmConstants() { /* * If we're using computed goto instruction transitions, make sure * none of the handlers overflows the byte limit. This won't tell * which one did, but if any one is too big the total size will * overflow. */ const int width = kNterpHandlerSize; ptrdiff_t interp_size = reinterpret_cast(artNterpAsmInstructionEnd) - reinterpret_cast(artNterpAsmInstructionStart); if ((interp_size == 0) || (interp_size != (art::kNumPackedOpcodes * width))) { LOG(FATAL) << "ERROR: unexpected asm interp size " << interp_size << "(did an instruction handler exceed " << width << " bytes?)"; } } inline void UpdateHotness(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) { // The hotness we will add to a method when we perform a // field/method/class/string lookup. constexpr uint16_t kNterpHotnessLookup = 0xf; method->UpdateCounter(kNterpHotnessLookup); } template inline void UpdateCache(Thread* self, uint16_t* dex_pc_ptr, T value) { DCHECK(kUseReadBarrier) << "Nterp only works with read barriers"; self->GetInterpreterCache()->Set(self, dex_pc_ptr, value); } template inline void UpdateCache(Thread* self, uint16_t* dex_pc_ptr, T* value) { UpdateCache(self, dex_pc_ptr, reinterpret_cast(value)); } #ifdef __arm__ extern "C" void NterpStoreArm32Fprs(const char* shorty, uint32_t* registers, uint32_t* stack_args, const uint32_t* fprs) { // Note `shorty` has already the returned type removed. ScopedAssertNoThreadSuspension sants("In nterp"); uint32_t arg_index = 0; uint32_t fpr_double_index = 0; uint32_t fpr_index = 0; for (uint32_t shorty_index = 0; shorty[shorty_index] != '\0'; ++shorty_index) { char arg_type = shorty[shorty_index]; switch (arg_type) { case 'D': { // Double should not overlap with float. fpr_double_index = std::max(fpr_double_index, RoundUp(fpr_index, 2)); if (fpr_double_index < 16) { registers[arg_index] = fprs[fpr_double_index++]; registers[arg_index + 1] = fprs[fpr_double_index++]; } else { registers[arg_index] = stack_args[arg_index]; registers[arg_index + 1] = stack_args[arg_index + 1]; } arg_index += 2; break; } case 'F': { if (fpr_index % 2 == 0) { fpr_index = std::max(fpr_double_index, fpr_index); } if (fpr_index < 16) { registers[arg_index] = fprs[fpr_index++]; } else { registers[arg_index] = stack_args[arg_index]; } arg_index++; break; } case 'J': { arg_index += 2; break; } default: { arg_index++; break; } } } } extern "C" void NterpSetupArm32Fprs(const char* shorty, uint32_t dex_register, uint32_t stack_index, uint32_t* fprs, uint32_t* registers, uint32_t* stack_args) { // Note `shorty` has already the returned type removed. ScopedAssertNoThreadSuspension sants("In nterp"); uint32_t fpr_double_index = 0; uint32_t fpr_index = 0; for (uint32_t shorty_index = 0; shorty[shorty_index] != '\0'; ++shorty_index) { char arg_type = shorty[shorty_index]; switch (arg_type) { case 'D': { // Double should not overlap with float. fpr_double_index = std::max(fpr_double_index, RoundUp(fpr_index, 2)); if (fpr_double_index < 16) { fprs[fpr_double_index++] = registers[dex_register++]; fprs[fpr_double_index++] = registers[dex_register++]; stack_index += 2; } else { stack_args[stack_index++] = registers[dex_register++]; stack_args[stack_index++] = registers[dex_register++]; } break; } case 'F': { if (fpr_index % 2 == 0) { fpr_index = std::max(fpr_double_index, fpr_index); } if (fpr_index < 16) { fprs[fpr_index++] = registers[dex_register++]; stack_index++; } else { stack_args[stack_index++] = registers[dex_register++]; } break; } case 'J': { stack_index += 2; dex_register += 2; break; } default: { stack_index++; dex_register++; break; } } } } #endif extern "C" const dex::CodeItem* NterpGetCodeItem(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); return method->GetCodeItem(); } extern "C" const char* NterpGetShorty(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); return method->GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetShorty(); } extern "C" const char* NterpGetShortyFromMethodId(ArtMethod* caller, uint32_t method_index) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); return caller->GetDexFile()->GetMethodShorty(method_index); } extern "C" const char* NterpGetShortyFromInvokePolymorphic(ArtMethod* caller, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); const Instruction* inst = Instruction::At(dex_pc_ptr); dex::ProtoIndex proto_idx(inst->Opcode() == Instruction::INVOKE_POLYMORPHIC ? inst->VRegH_45cc() : inst->VRegH_4rcc()); return caller->GetDexFile()->GetShorty(proto_idx); } extern "C" const char* NterpGetShortyFromInvokeCustom(ArtMethod* caller, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); const Instruction* inst = Instruction::At(dex_pc_ptr); uint16_t call_site_index = (inst->Opcode() == Instruction::INVOKE_CUSTOM ? inst->VRegB_35c() : inst->VRegB_3rc()); const DexFile* dex_file = caller->GetDexFile(); dex::ProtoIndex proto_idx = dex_file->GetProtoIndexForCallSite(call_site_index); return dex_file->GetShorty(proto_idx); } FLATTEN extern "C" size_t NterpGetMethod(Thread* self, ArtMethod* caller, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { UpdateHotness(caller); const Instruction* inst = Instruction::At(dex_pc_ptr); InvokeType invoke_type = kStatic; uint16_t method_index = 0; switch (inst->Opcode()) { case Instruction::INVOKE_DIRECT: { method_index = inst->VRegB_35c(); invoke_type = kDirect; break; } case Instruction::INVOKE_INTERFACE: { method_index = inst->VRegB_35c(); invoke_type = kInterface; break; } case Instruction::INVOKE_STATIC: { method_index = inst->VRegB_35c(); invoke_type = kStatic; break; } case Instruction::INVOKE_SUPER: { method_index = inst->VRegB_35c(); invoke_type = kSuper; break; } case Instruction::INVOKE_VIRTUAL: { method_index = inst->VRegB_35c(); invoke_type = kVirtual; break; } case Instruction::INVOKE_DIRECT_RANGE: { method_index = inst->VRegB_3rc(); invoke_type = kDirect; break; } case Instruction::INVOKE_INTERFACE_RANGE: { method_index = inst->VRegB_3rc(); invoke_type = kInterface; break; } case Instruction::INVOKE_STATIC_RANGE: { method_index = inst->VRegB_3rc(); invoke_type = kStatic; break; } case Instruction::INVOKE_SUPER_RANGE: { method_index = inst->VRegB_3rc(); invoke_type = kSuper; break; } case Instruction::INVOKE_VIRTUAL_RANGE: { method_index = inst->VRegB_3rc(); invoke_type = kVirtual; break; } default: LOG(FATAL) << "Unknown instruction " << inst->Opcode(); } ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); ArtMethod* resolved_method = caller->SkipAccessChecks() ? class_linker->ResolveMethod( self, method_index, caller, invoke_type) : class_linker->ResolveMethod( self, method_index, caller, invoke_type); if (resolved_method == nullptr) { DCHECK(self->IsExceptionPending()); return 0; } if (invoke_type == kSuper) { resolved_method = caller->SkipAccessChecks() ? FindSuperMethodToCall(method_index, resolved_method, caller, self) : FindSuperMethodToCall(method_index, resolved_method, caller, self); if (resolved_method == nullptr) { DCHECK(self->IsExceptionPending()); return 0; } } if (invoke_type == kInterface) { size_t result = 0u; if (resolved_method->GetDeclaringClass()->IsObjectClass()) { // Set the low bit to notify the interpreter it should do a vtable call. DCHECK_LT(resolved_method->GetMethodIndex(), 0x10000); result = (resolved_method->GetMethodIndex() << 16) | 1U; } else { DCHECK(resolved_method->GetDeclaringClass()->IsInterface()); DCHECK(!resolved_method->IsCopied()); if (!resolved_method->IsAbstract()) { // Set the second bit to notify the interpreter this is a default // method. result = reinterpret_cast(resolved_method) | 2U; } else { result = reinterpret_cast(resolved_method); } } UpdateCache(self, dex_pc_ptr, result); return result; } else if (resolved_method->GetDeclaringClass()->IsStringClass() && !resolved_method->IsStatic() && resolved_method->IsConstructor()) { CHECK_NE(invoke_type, kSuper); resolved_method = WellKnownClasses::StringInitToStringFactory(resolved_method); // Or the result with 1 to notify to nterp this is a string init method. We // also don't cache the result as we don't want nterp to have its fast path always // check for it, and we expect a lot more regular calls than string init // calls. return reinterpret_cast(resolved_method) | 1; } else if (invoke_type == kVirtual) { UpdateCache(self, dex_pc_ptr, resolved_method->GetMethodIndex()); return resolved_method->GetMethodIndex(); } else { UpdateCache(self, dex_pc_ptr, resolved_method); return reinterpret_cast(resolved_method); } } FLATTEN static ArtField* ResolveFieldWithAccessChecks(Thread* self, ClassLinker* class_linker, uint16_t field_index, ArtMethod* caller, bool is_static, bool is_put, size_t resolve_field_type) // Resolve if not zero REQUIRES_SHARED(Locks::mutator_lock_) { if (caller->SkipAccessChecks()) { return class_linker->ResolveField(field_index, caller, is_static); } caller = caller->GetInterfaceMethodIfProxy(kRuntimePointerSize); StackHandleScope<2> hs(self); Handle h_dex_cache(hs.NewHandle(caller->GetDexCache())); Handle h_class_loader(hs.NewHandle(caller->GetClassLoader())); ArtField* resolved_field = class_linker->ResolveFieldJLS(field_index, h_dex_cache, h_class_loader); if (resolved_field == nullptr) { return nullptr; } ObjPtr fields_class = resolved_field->GetDeclaringClass(); if (UNLIKELY(resolved_field->IsStatic() != is_static)) { ThrowIncompatibleClassChangeErrorField(resolved_field, is_static, caller); return nullptr; } ObjPtr referring_class = caller->GetDeclaringClass(); if (UNLIKELY(!referring_class->CheckResolvedFieldAccess(fields_class, resolved_field, caller->GetDexCache(), field_index))) { return nullptr; } if (UNLIKELY(is_put && resolved_field->IsFinal() && (fields_class != referring_class))) { ThrowIllegalAccessErrorFinalField(caller, resolved_field); return nullptr; } if (resolve_field_type != 0u && resolved_field->ResolveType() == nullptr) { DCHECK(self->IsExceptionPending()); return nullptr; } return resolved_field; } extern "C" size_t NterpGetStaticField(Thread* self, ArtMethod* caller, uint16_t* dex_pc_ptr, size_t resolve_field_type) // Resolve if not zero REQUIRES_SHARED(Locks::mutator_lock_) { UpdateHotness(caller); const Instruction* inst = Instruction::At(dex_pc_ptr); uint16_t field_index = inst->VRegB_21c(); ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); ArtField* resolved_field = ResolveFieldWithAccessChecks( self, class_linker, field_index, caller, /* is_static */ true, /* is_put */ IsInstructionSPut(inst->Opcode()), resolve_field_type); if (resolved_field == nullptr) { DCHECK(self->IsExceptionPending()); return 0; } if (UNLIKELY(!resolved_field->GetDeclaringClass()->IsVisiblyInitialized())) { StackHandleScope<1> hs(self); Handle h_class(hs.NewHandle(resolved_field->GetDeclaringClass())); if (UNLIKELY(!class_linker->EnsureInitialized( self, h_class, /*can_init_fields=*/ true, /*can_init_parents=*/ true))) { DCHECK(self->IsExceptionPending()); return 0; } DCHECK(h_class->IsInitializing()); } if (resolved_field->IsVolatile()) { // Or the result with 1 to notify to nterp this is a volatile field. We // also don't cache the result as we don't want nterp to have its fast path always // check for it. return reinterpret_cast(resolved_field) | 1; } else { UpdateCache(self, dex_pc_ptr, resolved_field); return reinterpret_cast(resolved_field); } } extern "C" uint32_t NterpGetInstanceFieldOffset(Thread* self, ArtMethod* caller, uint16_t* dex_pc_ptr, size_t resolve_field_type) // Resolve if not zero REQUIRES_SHARED(Locks::mutator_lock_) { UpdateHotness(caller); const Instruction* inst = Instruction::At(dex_pc_ptr); uint16_t field_index = inst->VRegC_22c(); ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); ArtField* resolved_field = ResolveFieldWithAccessChecks( self, class_linker, field_index, caller, /* is_static */ false, /* is_put */ IsInstructionIPut(inst->Opcode()), resolve_field_type); if (resolved_field == nullptr) { DCHECK(self->IsExceptionPending()); return 0; } if (resolved_field->IsVolatile()) { // Don't cache for a volatile field, and return a negative offset as marker // of volatile. return -resolved_field->GetOffset().Uint32Value(); } UpdateCache(self, dex_pc_ptr, resolved_field->GetOffset().Uint32Value()); return resolved_field->GetOffset().Uint32Value(); } extern "C" mirror::Object* NterpGetClassOrAllocateObject(Thread* self, ArtMethod* caller, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { UpdateHotness(caller); const Instruction* inst = Instruction::At(dex_pc_ptr); dex::TypeIndex index; switch (inst->Opcode()) { case Instruction::NEW_INSTANCE: index = dex::TypeIndex(inst->VRegB_21c()); break; case Instruction::CHECK_CAST: index = dex::TypeIndex(inst->VRegB_21c()); break; case Instruction::INSTANCE_OF: index = dex::TypeIndex(inst->VRegC_22c()); break; case Instruction::CONST_CLASS: index = dex::TypeIndex(inst->VRegB_21c()); break; case Instruction::NEW_ARRAY: index = dex::TypeIndex(inst->VRegC_22c()); break; default: LOG(FATAL) << "Unreachable"; } ObjPtr c = ResolveVerifyAndClinit(index, caller, self, /* can_run_clinit= */ false, /* verify_access= */ !caller->SkipAccessChecks()); if (c == nullptr) { DCHECK(self->IsExceptionPending()); return nullptr; } if (inst->Opcode() == Instruction::NEW_INSTANCE) { gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator(); if (UNLIKELY(c->IsStringClass())) { // We don't cache the class for strings as we need to special case their // allocation. return mirror::String::AllocEmptyString(self, allocator_type).Ptr(); } else { if (!c->IsFinalizable() && c->IsInstantiable()) { // Cache non-finalizable classes for next calls. UpdateCache(self, dex_pc_ptr, c.Ptr()); } return AllocObjectFromCode(c, self, allocator_type).Ptr(); } } else { // For all other cases, cache the class. UpdateCache(self, dex_pc_ptr, c.Ptr()); } return c.Ptr(); } extern "C" mirror::Object* NterpLoadObject(Thread* self, ArtMethod* caller, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { const Instruction* inst = Instruction::At(dex_pc_ptr); ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); switch (inst->Opcode()) { case Instruction::CONST_STRING: case Instruction::CONST_STRING_JUMBO: { UpdateHotness(caller); dex::StringIndex string_index( (inst->Opcode() == Instruction::CONST_STRING) ? inst->VRegB_21c() : inst->VRegB_31c()); ObjPtr str = class_linker->ResolveString(string_index, caller); if (str == nullptr) { DCHECK(self->IsExceptionPending()); return nullptr; } UpdateCache(self, dex_pc_ptr, str.Ptr()); return str.Ptr(); } case Instruction::CONST_METHOD_HANDLE: { // Don't cache: we don't expect this to be performance sensitive, and we // don't want the cache to conflict with a performance sensitive entry. return class_linker->ResolveMethodHandle(self, inst->VRegB_21c(), caller).Ptr(); } case Instruction::CONST_METHOD_TYPE: { // Don't cache: we don't expect this to be performance sensitive, and we // don't want the cache to conflict with a performance sensitive entry. return class_linker->ResolveMethodType( self, dex::ProtoIndex(inst->VRegB_21c()), caller).Ptr(); } default: LOG(FATAL) << "Unreachable"; } return nullptr; } extern "C" void NterpUnimplemented() { LOG(FATAL) << "Unimplemented"; } static mirror::Object* DoFilledNewArray(Thread* self, ArtMethod* caller, uint16_t* dex_pc_ptr, uint32_t* regs, bool is_range) REQUIRES_SHARED(Locks::mutator_lock_) { const Instruction* inst = Instruction::At(dex_pc_ptr); if (kIsDebugBuild) { if (is_range) { DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY_RANGE); } else { DCHECK_EQ(inst->Opcode(), Instruction::FILLED_NEW_ARRAY); } } const int32_t length = is_range ? inst->VRegA_3rc() : inst->VRegA_35c(); DCHECK_GE(length, 0); if (!is_range) { // Checks FILLED_NEW_ARRAY's length does not exceed 5 arguments. DCHECK_LE(length, 5); } uint16_t type_idx = is_range ? inst->VRegB_3rc() : inst->VRegB_35c(); ObjPtr array_class = ResolveVerifyAndClinit(dex::TypeIndex(type_idx), caller, self, /* can_run_clinit= */ true, /* verify_access= */ !caller->SkipAccessChecks()); if (UNLIKELY(array_class == nullptr)) { DCHECK(self->IsExceptionPending()); return nullptr; } DCHECK(array_class->IsArrayClass()); ObjPtr component_class = array_class->GetComponentType(); const bool is_primitive_int_component = component_class->IsPrimitiveInt(); if (UNLIKELY(component_class->IsPrimitive() && !is_primitive_int_component)) { if (component_class->IsPrimitiveLong() || component_class->IsPrimitiveDouble()) { ThrowRuntimeException("Bad filled array request for type %s", component_class->PrettyDescriptor().c_str()); } else { self->ThrowNewExceptionF( "Ljava/lang/InternalError;", "Found type %s; filled-new-array not implemented for anything but 'int'", component_class->PrettyDescriptor().c_str()); } return nullptr; } ObjPtr new_array = mirror::Array::Alloc( self, array_class, length, array_class->GetComponentSizeShift(), Runtime::Current()->GetHeap()->GetCurrentAllocator()); if (UNLIKELY(new_array == nullptr)) { self->AssertPendingOOMException(); return nullptr; } uint32_t arg[Instruction::kMaxVarArgRegs]; // only used in filled-new-array. uint32_t vregC = 0; // only used in filled-new-array-range. if (is_range) { vregC = inst->VRegC_3rc(); } else { inst->GetVarArgs(arg); } for (int32_t i = 0; i < length; ++i) { size_t src_reg = is_range ? vregC + i : arg[i]; if (is_primitive_int_component) { new_array->AsIntArray()->SetWithoutChecks(i, regs[src_reg]); } else { new_array->AsObjectArray()->SetWithoutChecks( i, reinterpret_cast(regs[src_reg])); } } return new_array.Ptr(); } extern "C" mirror::Object* NterpFilledNewArray(Thread* self, ArtMethod* caller, uint32_t* registers, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { return DoFilledNewArray(self, caller, dex_pc_ptr, registers, /* is_range= */ false); } extern "C" mirror::Object* NterpFilledNewArrayRange(Thread* self, ArtMethod* caller, uint32_t* registers, uint16_t* dex_pc_ptr) REQUIRES_SHARED(Locks::mutator_lock_) { return DoFilledNewArray(self, caller, dex_pc_ptr, registers, /* is_range= */ true); } extern "C" jit::OsrData* NterpHotMethod(ArtMethod* method, uint16_t* dex_pc_ptr, uint32_t* vregs) REQUIRES_SHARED(Locks::mutator_lock_) { // It is important this method is not suspended because it can be called on // method entry and async deoptimization does not expect runtime methods other than the // suspend entrypoint before executing the first instruction of a Java // method. ScopedAssertNoThreadSuspension sants("In nterp"); Runtime* runtime = Runtime::Current(); if (method->IsMemorySharedMethod()) { DCHECK_EQ(Thread::Current()->GetSharedMethodHotness(), 0u); Thread::Current()->ResetSharedMethodHotness(); } else { method->ResetCounter(runtime->GetJITOptions()->GetWarmupThreshold()); } jit::Jit* jit = runtime->GetJit(); if (jit != nullptr && jit->UseJitCompilation()) { // Nterp passes null on entry where we don't want to OSR. if (dex_pc_ptr != nullptr) { // This could be a loop back edge, check if we can OSR. CodeItemInstructionAccessor accessor(method->DexInstructions()); uint32_t dex_pc = dex_pc_ptr - accessor.Insns(); jit::OsrData* osr_data = jit->PrepareForOsr( method->GetInterfaceMethodIfProxy(kRuntimePointerSize), dex_pc, vregs); if (osr_data != nullptr) { return osr_data; } } jit->MaybeEnqueueCompilation(method, Thread::Current()); } return nullptr; } extern "C" ssize_t NterpDoPackedSwitch(const uint16_t* switchData, int32_t testVal) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); const int kInstrLen = 3; /* * Packed switch data format: * ushort ident = 0x0100 magic value * ushort size number of entries in the table * int first_key first (and lowest) switch case value * int targets[size] branch targets, relative to switch opcode * * Total size is (4+size*2) 16-bit code units. */ uint16_t signature = *switchData++; DCHECK_EQ(signature, static_cast(art::Instruction::kPackedSwitchSignature)); uint16_t size = *switchData++; int32_t firstKey = *switchData++; firstKey |= (*switchData++) << 16; int index = testVal - firstKey; if (index < 0 || index >= size) { return kInstrLen; } /* * The entries are guaranteed to be aligned on a 32-bit boundary; * we can treat them as a native int array. */ const int32_t* entries = reinterpret_cast(switchData); return entries[index]; } /* * Find the matching case. Returns the offset to the handler instructions. * * Returns 3 if we don't find a match (it's the size of the sparse-switch * instruction). */ extern "C" ssize_t NterpDoSparseSwitch(const uint16_t* switchData, int32_t testVal) REQUIRES_SHARED(Locks::mutator_lock_) { ScopedAssertNoThreadSuspension sants("In nterp"); const int kInstrLen = 3; uint16_t size; const int32_t* keys; const int32_t* entries; /* * Sparse switch data format: * ushort ident = 0x0200 magic value * ushort size number of entries in the table; > 0 * int keys[size] keys, sorted low-to-high; 32-bit aligned * int targets[size] branch targets, relative to switch opcode * * Total size is (2+size*4) 16-bit code units. */ uint16_t signature = *switchData++; DCHECK_EQ(signature, static_cast(art::Instruction::kSparseSwitchSignature)); size = *switchData++; /* The keys are guaranteed to be aligned on a 32-bit boundary; * we can treat them as a native int array. */ keys = reinterpret_cast(switchData); /* The entries are guaranteed to be aligned on a 32-bit boundary; * we can treat them as a native int array. */ entries = keys + size; /* * Binary-search through the array of keys, which are guaranteed to * be sorted low-to-high. */ int lo = 0; int hi = size - 1; while (lo <= hi) { int mid = (lo + hi) >> 1; int32_t foundVal = keys[mid]; if (testVal < foundVal) { hi = mid - 1; } else if (testVal > foundVal) { lo = mid + 1; } else { return entries[mid]; } } return kInstrLen; } extern "C" void NterpFree(void* val) { free(val); } } // namespace interpreter } // namespace art