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// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/compiler/runtime_api.h"
#include "vm/globals.h"
// For `AllocateObjectInstr::WillAllocateNewOrRemembered`
// For `GenericCheckBoundInstr::UseUnboxedRepresentation`
#include "vm/compiler/backend/il.h"
#define SHOULD_NOT_INCLUDE_RUNTIME
#include "vm/compiler/stub_code_compiler.h"
#if defined(TARGET_ARCH_ARM)
#include "vm/class_id.h"
#include "vm/code_entry_kind.h"
#include "vm/compiler/api/type_check_mode.h"
#include "vm/compiler/assembler/assembler.h"
#include "vm/compiler/backend/locations.h"
#include "vm/constants.h"
#include "vm/instructions.h"
#include "vm/static_type_exactness_state.h"
#include "vm/tags.h"
#define __ assembler->
namespace dart {
DEFINE_FLAG(bool, inline_alloc, true, "Inline allocation of objects.");
DEFINE_FLAG(bool,
use_slow_path,
false,
"Set to true for debugging & verifying the slow paths.");
DECLARE_FLAG(bool, precompiled_mode);
namespace compiler {
// Ensures that [R0] is a new object, if not it will be added to the remembered
// set via a leaf runtime call.
//
// WARNING: This might clobber all registers except for [R0], [THR] and [FP].
// The caller should simply call LeaveStubFrame() and return.
static void EnsureIsNewOrRemembered(Assembler* assembler,
bool preserve_registers = true) {
// If the object is not remembered we call a leaf-runtime to add it to the
// remembered set.
Label done;
__ tst(R0, Operand(1 << target::ObjectAlignment::kNewObjectBitPosition));
__ BranchIf(NOT_ZERO, &done);
if (preserve_registers) {
__ EnterCallRuntimeFrame(0);
} else {
__ ReserveAlignedFrameSpace(0);
}
// [R0] already contains first argument.
__ mov(R1, Operand(THR));
__ CallRuntime(kEnsureRememberedAndMarkingDeferredRuntimeEntry, 2);
if (preserve_registers) {
__ LeaveCallRuntimeFrame();
}
__ Bind(&done);
}
// Input parameters:
// LR : return address.
// SP : address of last argument in argument array.
// SP + 4*R4 - 4 : address of first argument in argument array.
// SP + 4*R4 : address of return value.
// R9 : address of the runtime function to call.
// R4 : number of arguments to the call.
void StubCodeCompiler::GenerateCallToRuntimeStub(Assembler* assembler) {
const intptr_t thread_offset = target::NativeArguments::thread_offset();
const intptr_t argc_tag_offset = target::NativeArguments::argc_tag_offset();
const intptr_t argv_offset = target::NativeArguments::argv_offset();
const intptr_t retval_offset = target::NativeArguments::retval_offset();
__ ldr(CODE_REG, Address(THR, target::Thread::call_to_runtime_stub_offset()));
__ EnterStubFrame();
// Save exit frame information to enable stack walking as we are about
// to transition to Dart VM C++ code.
__ StoreToOffset(FP, THR, target::Thread::top_exit_frame_info_offset());
// Mark that the thread exited generated code through a runtime call.
__ LoadImmediate(R8, target::Thread::exit_through_runtime_call());
__ StoreToOffset(R8, THR, target::Thread::exit_through_ffi_offset());
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R8, THR, target::Thread::vm_tag_offset());
__ CompareImmediate(R8, VMTag::kDartTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Mark that the thread is executing VM code.
__ StoreToOffset(R9, THR, target::Thread::vm_tag_offset());
// Reserve space for arguments and align frame before entering C++ world.
// target::NativeArguments are passed in registers.
ASSERT(target::NativeArguments::StructSize() == 4 * target::kWordSize);
__ ReserveAlignedFrameSpace(0);
// Pass target::NativeArguments structure by value and call runtime.
// Registers R0, R1, R2, and R3 are used.
ASSERT(thread_offset == 0 * target::kWordSize);
// Set thread in NativeArgs.
__ mov(R0, Operand(THR));
// There are no runtime calls to closures, so we do not need to set the tag
// bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
ASSERT(argc_tag_offset == 1 * target::kWordSize);
__ mov(R1, Operand(R4)); // Set argc in target::NativeArguments.
ASSERT(argv_offset == 2 * target::kWordSize);
__ add(R2, FP, Operand(R4, LSL, 2)); // Compute argv.
// Set argv in target::NativeArguments.
__ AddImmediate(R2,
target::frame_layout.param_end_from_fp * target::kWordSize);
ASSERT(retval_offset == 3 * target::kWordSize);
__ add(R3, R2,
Operand(target::kWordSize)); // Retval is next to 1st argument.
// Call runtime or redirection via simulator.
__ blx(R9);
// Mark that the thread is executing Dart code.
__ LoadImmediate(R2, VMTag::kDartTagId);
__ StoreToOffset(R2, THR, target::Thread::vm_tag_offset());
// Mark that the thread has not exited generated Dart code.
__ LoadImmediate(R2, 0);
__ StoreToOffset(R2, THR, target::Thread::exit_through_ffi_offset());
// Reset exit frame information in Isolate's mutator thread structure.
__ StoreToOffset(R2, THR, target::Thread::top_exit_frame_info_offset());
// Restore the global object pool after returning from runtime (old space is
// moving, so the GOP could have been relocated).
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ SetupGlobalPoolAndDispatchTable();
}
__ LeaveStubFrame();
// The following return can jump to a lazy-deopt stub, which assumes R0
// contains a return value and will save it in a GC-visible way. We therefore
// have to ensure R0 does not contain any garbage value left from the C
// function we called (which has return type "void").
// (See GenerateDeoptimizationSequence::saved_result_slot_from_fp.)
__ LoadImmediate(R0, 0);
__ Ret();
}
void StubCodeCompiler::GenerateSharedStubGeneric(
Assembler* assembler,
bool save_fpu_registers,
intptr_t self_code_stub_offset_from_thread,
bool allow_return,
std::function<void()> perform_runtime_call) {
// If the target CPU does not support VFP the caller should always use the
// non-FPU stub.
if (save_fpu_registers && !TargetCPUFeatures::vfp_supported()) {
__ Breakpoint();
return;
}
// We want the saved registers to appear like part of the caller's frame, so
// we push them before calling EnterStubFrame.
RegisterSet all_registers;
all_registers.AddAllNonReservedRegisters(save_fpu_registers);
// To make the stack map calculation architecture independent we do the same
// as on intel.
READS_RETURN_ADDRESS_FROM_LR(__ Push(LR));
__ PushRegisters(all_registers);
__ ldr(CODE_REG, Address(THR, self_code_stub_offset_from_thread));
__ EnterStubFrame();
perform_runtime_call();
if (!allow_return) {
__ Breakpoint();
return;
}
__ LeaveStubFrame();
__ PopRegisters(all_registers);
__ Drop(1); // We use the LR restored via LeaveStubFrame.
READS_RETURN_ADDRESS_FROM_LR(__ bx(LR));
}
void StubCodeCompiler::GenerateSharedStub(
Assembler* assembler,
bool save_fpu_registers,
const RuntimeEntry* target,
intptr_t self_code_stub_offset_from_thread,
bool allow_return,
bool store_runtime_result_in_result_register) {
ASSERT(!store_runtime_result_in_result_register || allow_return);
auto perform_runtime_call = [&]() {
if (store_runtime_result_in_result_register) {
// Reserve space for the result on the stack. This needs to be a GC
// safe value.
__ PushImmediate(Smi::RawValue(0));
}
__ CallRuntime(*target, /*argument_count=*/0);
if (store_runtime_result_in_result_register) {
__ PopRegister(R0);
__ str(R0,
Address(FP, target::kWordSize *
StubCodeCompiler::WordOffsetFromFpToCpuRegister(
SharedSlowPathStubABI::kResultReg)));
}
};
GenerateSharedStubGeneric(assembler, save_fpu_registers,
self_code_stub_offset_from_thread, allow_return,
perform_runtime_call);
}
// R1: The extracted method.
// R4: The type_arguments_field_offset (or 0)
// SP+0: The object from which we are tearing a method off.
void StubCodeCompiler::GenerateBuildMethodExtractorStub(
Assembler* assembler,
const Object& closure_allocation_stub,
const Object& context_allocation_stub) {
const intptr_t kReceiverOffset = target::frame_layout.param_end_from_fp + 1;
__ EnterStubFrame();
// Build type_arguments vector (or null)
__ cmp(R4, Operand(0));
__ ldr(R3, Address(THR, target::Thread::object_null_offset()), EQ);
__ ldr(R0, Address(FP, kReceiverOffset * target::kWordSize), NE);
__ ldr(R3, Address(R0, R4), NE);
// Push type arguments & extracted method.
__ PushList(1 << R3 | 1 << R1);
// Allocate context.
{
Label done, slow_path;
__ TryAllocateArray(kContextCid, target::Context::InstanceSize(1),
&slow_path,
R0, // instance
R1, // end address
R2, R3);
__ ldr(R1, Address(THR, target::Thread::object_null_offset()));
__ str(R1, FieldAddress(R0, target::Context::parent_offset()));
__ LoadImmediate(R1, 1);
__ str(R1, FieldAddress(R0, target::Context::num_variables_offset()));
__ b(&done);
__ Bind(&slow_path);
__ LoadImmediate(/*num_vars=*/R1, 1);
__ LoadObject(CODE_REG, context_allocation_stub);
__ ldr(R0, FieldAddress(CODE_REG, target::Code::entry_point_offset()));
__ blx(R0);
__ Bind(&done);
}
// Store receiver in context
__ ldr(R1, Address(FP, target::kWordSize * kReceiverOffset));
__ StoreIntoObject(R0, FieldAddress(R0, target::Context::variable_offset(0)),
R1);
// Push context.
__ Push(R0);
// Allocate closure.
__ LoadObject(CODE_REG, closure_allocation_stub);
__ ldr(R1, FieldAddress(CODE_REG, target::Code::entry_point_offset(
CodeEntryKind::kUnchecked)));
__ blx(R1);
// Populate closure object.
__ Pop(R1); // Pop context.
__ StoreIntoObject(R0, FieldAddress(R0, target::Closure::context_offset()),
R1);
__ PopList(1 << R3 | 1 << R1); // Pop type arguments & extracted method.
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Closure::function_offset()), R1);
__ StoreIntoObjectNoBarrier(
R0,
FieldAddress(R0, target::Closure::instantiator_type_arguments_offset()),
R3);
__ LoadObject(R1, EmptyTypeArguments());
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Closure::delayed_type_arguments_offset()),
R1);
__ LeaveStubFrame();
__ Ret();
}
void StubCodeCompiler::GenerateEnterSafepointStub(Assembler* assembler) {
RegisterSet all_registers;
all_registers.AddAllGeneralRegisters();
__ PushRegisters(all_registers);
SPILLS_LR_TO_FRAME(__ EnterFrame((1 << FP) | (1 << LR), 0));
__ ReserveAlignedFrameSpace(0);
__ ldr(R0, Address(THR, kEnterSafepointRuntimeEntry.OffsetFromThread()));
__ blx(R0);
RESTORES_LR_FROM_FRAME(__ LeaveFrame((1 << FP) | (1 << LR), 0));
__ PopRegisters(all_registers);
__ Ret();
}
void StubCodeCompiler::GenerateExitSafepointStub(Assembler* assembler) {
RegisterSet all_registers;
all_registers.AddAllGeneralRegisters();
__ PushRegisters(all_registers);
SPILLS_LR_TO_FRAME(__ EnterFrame((1 << FP) | (1 << LR), 0));
__ ReserveAlignedFrameSpace(0);
// Set the execution state to VM while waiting for the safepoint to end.
// This isn't strictly necessary but enables tests to check that we're not
// in native code anymore. See tests/ffi/function_gc_test.dart for example.
__ LoadImmediate(R0, target::Thread::vm_execution_state());
__ str(R0, Address(THR, target::Thread::execution_state_offset()));
__ ldr(R0, Address(THR, kExitSafepointRuntimeEntry.OffsetFromThread()));
__ blx(R0);
RESTORES_LR_FROM_FRAME(__ LeaveFrame((1 << FP) | (1 << LR), 0));
__ PopRegisters(all_registers);
__ Ret();
}
// Call a native function within a safepoint.
//
// On entry:
// Stack: set up for call, incl. alignment
// R8: target to call
//
// On exit:
// Stack: preserved
// NOTFP, R4: clobbered, although normally callee-saved
void StubCodeCompiler::GenerateCallNativeThroughSafepointStub(
Assembler* assembler) {
COMPILE_ASSERT(IsAbiPreservedRegister(R4));
// TransitionGeneratedToNative might clobber LR if it takes the slow path.
SPILLS_RETURN_ADDRESS_FROM_LR_TO_REGISTER(__ mov(R4, Operand(LR)));
__ LoadImmediate(R9, target::Thread::exit_through_ffi());
__ TransitionGeneratedToNative(R8, FPREG, R9 /*volatile*/, NOTFP,
/*enter_safepoint=*/true);
__ blx(R8);
__ TransitionNativeToGenerated(R9 /*volatile*/, NOTFP,
/*exit_safepoint=*/true);
__ bx(R4);
}
#if !defined(DART_PRECOMPILER)
void StubCodeCompiler::GenerateJITCallbackTrampolines(
Assembler* assembler,
intptr_t next_callback_id) {
#if defined(USING_SIMULATOR)
// TODO(37299): FFI is not support in SIMARM.
__ Breakpoint();
#else
Label done;
// TMP is volatile and not used for passing any arguments.
COMPILE_ASSERT(!IsCalleeSavedRegister(TMP) && !IsArgumentRegister(TMP));
for (intptr_t i = 0;
i < NativeCallbackTrampolines::NumCallbackTrampolinesPerPage(); ++i) {
// We don't use LoadImmediate because we need the trampoline size to be
// fixed independently of the callback ID.
//
// PC points two instructions ahead of the current one -- directly where we
// store the callback ID.
__ ldr(TMP, Address(PC, 0));
__ b(&done);
__ Emit(next_callback_id + i);
}
ASSERT(__ CodeSize() ==
kNativeCallbackTrampolineSize *
NativeCallbackTrampolines::NumCallbackTrampolinesPerPage());
__ Bind(&done);
const intptr_t shared_stub_start = __ CodeSize();
// Save THR (callee-saved), R4 & R5 (temporaries, callee-saved), and LR.
COMPILE_ASSERT(StubCodeCompiler::kNativeCallbackTrampolineStackDelta == 4);
SPILLS_LR_TO_FRAME(
__ PushList((1 << LR) | (1 << THR) | (1 << R4) | (1 << R5)));
// Don't rely on TMP being preserved by assembler macros anymore.
__ mov(R4, Operand(TMP));
COMPILE_ASSERT(IsCalleeSavedRegister(R4));
COMPILE_ASSERT(!IsArgumentRegister(THR));
RegisterSet argument_registers;
argument_registers.AddAllArgumentRegisters();
__ PushRegisters(argument_registers);
// Load the thread, verify the callback ID and exit the safepoint.
//
// We exit the safepoint inside DLRT_GetThreadForNativeCallbackTrampoline
// in order to safe code size on this shared stub.
{
__ EnterFrame(1 << FP, 0);
__ ReserveAlignedFrameSpace(0);
__ mov(R0, Operand(R4));
// Since DLRT_GetThreadForNativeCallbackTrampoline can theoretically be
// loaded anywhere, we use the same trick as before to ensure a predictable
// instruction sequence.
Label call;
__ ldr(R1, Address(PC, 0));
__ b(&call);
__ Emit(
reinterpret_cast<intptr_t>(&DLRT_GetThreadForNativeCallbackTrampoline));
__ Bind(&call);
__ blx(R1);
__ mov(THR, Operand(R0));
__ LeaveFrame(1 << FP);
}
__ PopRegisters(argument_registers);
COMPILE_ASSERT(!IsArgumentRegister(R8));
// Load the code object.
__ LoadFromOffset(R5, THR, compiler::target::Thread::callback_code_offset());
__ LoadFieldFromOffset(R5, R5,
compiler::target::GrowableObjectArray::data_offset());
__ ldr(R5, __ ElementAddressForRegIndex(
/*is_load=*/true,
/*external=*/false,
/*array_cid=*/kArrayCid,
/*index_scale, smi-tagged=*/compiler::target::kWordSize * 2,
/*index_unboxed=*/false,
/*array=*/R5,
/*index=*/R4));
__ LoadFieldFromOffset(R5, R5, compiler::target::Code::entry_point_offset());
// On entry to the function, there will be four extra slots on the stack:
// saved THR, R4, R5 and the return address. The target will know to skip
// them.
__ blx(R5);
// EnterSafepoint clobbers R4, R5 and TMP, all saved or volatile.
__ EnterSafepoint(R4, R5);
// Returns.
__ PopList((1 << PC) | (1 << THR) | (1 << R4) | (1 << R5));
ASSERT((__ CodeSize() - shared_stub_start) == kNativeCallbackSharedStubSize);
ASSERT(__ CodeSize() <= VirtualMemory::PageSize());
#if defined(DEBUG)
while (__ CodeSize() < VirtualMemory::PageSize()) {
__ Breakpoint();
}
#endif
#endif
}
#endif // !defined(DART_PRECOMPILER)
void StubCodeCompiler::GenerateDispatchTableNullErrorStub(
Assembler* assembler) {
__ EnterStubFrame();
__ CallRuntime(kNullErrorRuntimeEntry, /*argument_count=*/0);
// The NullError runtime entry does not return.
__ Breakpoint();
}
void StubCodeCompiler::GenerateRangeError(Assembler* assembler,
bool with_fpu_regs) {
auto perform_runtime_call = [&]() {
ASSERT(!GenericCheckBoundInstr::UseUnboxedRepresentation());
__ PushRegister(RangeErrorABI::kLengthReg);
__ PushRegister(RangeErrorABI::kIndexReg);
__ CallRuntime(kRangeErrorRuntimeEntry, /*argument_count=*/2);
__ Breakpoint();
};
GenerateSharedStubGeneric(
assembler, /*save_fpu_registers=*/with_fpu_regs,
with_fpu_regs
? target::Thread::range_error_shared_with_fpu_regs_stub_offset()
: target::Thread::range_error_shared_without_fpu_regs_stub_offset(),
/*allow_return=*/false, perform_runtime_call);
}
// Input parameters:
// LR : return address.
// SP : address of return value.
// R9 : address of the native function to call.
// R2 : address of first argument in argument array.
// R1 : argc_tag including number of arguments and function kind.
static void GenerateCallNativeWithWrapperStub(Assembler* assembler,
Address wrapper) {
const intptr_t thread_offset = target::NativeArguments::thread_offset();
const intptr_t argc_tag_offset = target::NativeArguments::argc_tag_offset();
const intptr_t argv_offset = target::NativeArguments::argv_offset();
const intptr_t retval_offset = target::NativeArguments::retval_offset();
__ EnterStubFrame();
// Save exit frame information to enable stack walking as we are about
// to transition to native code.
__ StoreToOffset(FP, THR, target::Thread::top_exit_frame_info_offset());
// Mark that the thread exited generated code through a runtime call.
__ LoadImmediate(R8, target::Thread::exit_through_runtime_call());
__ StoreToOffset(R8, THR, target::Thread::exit_through_ffi_offset());
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R8, THR, target::Thread::vm_tag_offset());
__ CompareImmediate(R8, VMTag::kDartTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Mark that the thread is executing native code.
__ StoreToOffset(R9, THR, target::Thread::vm_tag_offset());
// Reserve space for the native arguments structure passed on the stack (the
// outgoing pointer parameter to the native arguments structure is passed in
// R0) and align frame before entering the C++ world.
__ ReserveAlignedFrameSpace(target::NativeArguments::StructSize());
// Initialize target::NativeArguments structure and call native function.
// Registers R0, R1, R2, and R3 are used.
ASSERT(thread_offset == 0 * target::kWordSize);
// Set thread in NativeArgs.
__ mov(R0, Operand(THR));
// There are no native calls to closures, so we do not need to set the tag
// bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
ASSERT(argc_tag_offset == 1 * target::kWordSize);
// Set argc in target::NativeArguments: R1 already contains argc.
ASSERT(argv_offset == 2 * target::kWordSize);
// Set argv in target::NativeArguments: R2 already contains argv.
// Set retval in NativeArgs.
ASSERT(retval_offset == 3 * target::kWordSize);
__ add(R3, FP, Operand(2 * target::kWordSize));
// Passing the structure by value as in runtime calls would require changing
// Dart API for native functions.
// For now, space is reserved on the stack and we pass a pointer to it.
__ stm(IA, SP, (1 << R0) | (1 << R1) | (1 << R2) | (1 << R3));
__ mov(R0, Operand(SP)); // Pass the pointer to the target::NativeArguments.
__ mov(R1, Operand(R9)); // Pass the function entrypoint to call.
// Call native function invocation wrapper or redirection via simulator.
__ Call(wrapper);
// Mark that the thread is executing Dart code.
__ LoadImmediate(R2, VMTag::kDartTagId);
__ StoreToOffset(R2, THR, target::Thread::vm_tag_offset());
// Mark that the thread has not exited generated Dart code.
__ LoadImmediate(R2, 0);
__ StoreToOffset(R2, THR, target::Thread::exit_through_ffi_offset());
// Reset exit frame information in Isolate's mutator thread structure.
__ StoreToOffset(R2, THR, target::Thread::top_exit_frame_info_offset());
// Restore the global object pool after returning from runtime (old space is
// moving, so the GOP could have been relocated).
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ SetupGlobalPoolAndDispatchTable();
}
__ LeaveStubFrame();
__ Ret();
}
void StubCodeCompiler::GenerateCallNoScopeNativeStub(Assembler* assembler) {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR,
target::Thread::no_scope_native_wrapper_entry_point_offset()));
}
void StubCodeCompiler::GenerateCallAutoScopeNativeStub(Assembler* assembler) {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR,
target::Thread::auto_scope_native_wrapper_entry_point_offset()));
}
// Input parameters:
// LR : return address.
// SP : address of return value.
// R9 : address of the native function to call.
// R2 : address of first argument in argument array.
// R1 : argc_tag including number of arguments and function kind.
void StubCodeCompiler::GenerateCallBootstrapNativeStub(Assembler* assembler) {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR,
target::Thread::bootstrap_native_wrapper_entry_point_offset()));
}
// Input parameters:
// R4: arguments descriptor array.
void StubCodeCompiler::GenerateCallStaticFunctionStub(Assembler* assembler) {
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
// Setup space on stack for return value and preserve arguments descriptor.
__ LoadImmediate(R0, 0);
__ PushList((1 << R0) | (1 << R4));
__ CallRuntime(kPatchStaticCallRuntimeEntry, 0);
// Get Code object result and restore arguments descriptor array.
__ PopList((1 << R0) | (1 << R4));
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ mov(CODE_REG, Operand(R0));
__ Branch(FieldAddress(R0, target::Code::entry_point_offset()));
}
// Called from a static call only when an invalid code has been entered
// (invalid because its function was optimized or deoptimized).
// R4: arguments descriptor array.
void StubCodeCompiler::GenerateFixCallersTargetStub(Assembler* assembler) {
Label monomorphic;
__ BranchOnMonomorphicCheckedEntryJIT(&monomorphic);
// Load code pointer to this stub from the thread:
// The one that is passed in, is not correct - it points to the code object
// that needs to be replaced.
__ ldr(CODE_REG,
Address(THR, target::Thread::fix_callers_target_code_offset()));
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
// Setup space on stack for return value and preserve arguments descriptor.
__ LoadImmediate(R0, 0);
__ PushList((1 << R0) | (1 << R4));
__ CallRuntime(kFixCallersTargetRuntimeEntry, 0);
// Get Code object result and restore arguments descriptor array.
__ PopList((1 << R0) | (1 << R4));
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ mov(CODE_REG, Operand(R0));
__ Branch(FieldAddress(R0, target::Code::entry_point_offset()));
__ Bind(&monomorphic);
// Load code pointer to this stub from the thread:
// The one that is passed in, is not correct - it points to the code object
// that needs to be replaced.
__ ldr(CODE_REG,
Address(THR, target::Thread::fix_callers_target_code_offset()));
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
__ LoadImmediate(R1, 0);
__ Push(R9); // Preserve cache (guarded CID as Smi).
__ Push(R0); // Preserve receiver.
__ Push(R1);
__ CallRuntime(kFixCallersTargetMonomorphicRuntimeEntry, 0);
__ Pop(CODE_REG);
__ Pop(R0); // Restore receiver.
__ Pop(R9); // Restore cache (guarded CID as Smi).
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ Branch(FieldAddress(
CODE_REG, target::Code::entry_point_offset(CodeEntryKind::kMonomorphic)));
}
// Called from object allocate instruction when the allocation stub has been
// disabled.
void StubCodeCompiler::GenerateFixAllocationStubTargetStub(
Assembler* assembler) {
// Load code pointer to this stub from the thread:
// The one that is passed in, is not correct - it points to the code object
// that needs to be replaced.
__ ldr(CODE_REG,
Address(THR, target::Thread::fix_allocation_stub_code_offset()));
__ EnterStubFrame();
// Setup space on stack for return value.
__ LoadImmediate(R0, 0);
__ Push(R0);
__ CallRuntime(kFixAllocationStubTargetRuntimeEntry, 0);
// Get Code object result.
__ Pop(R0);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ mov(CODE_REG, Operand(R0));
__ Branch(FieldAddress(R0, target::Code::entry_point_offset()));
}
// Input parameters:
// R2: smi-tagged argument count, may be zero.
// FP[target::frame_layout.param_end_from_fp + 1]: last argument.
static void PushArrayOfArguments(Assembler* assembler) {
// Allocate array to store arguments of caller.
__ LoadObject(R1, NullObject());
// R1: null element type for raw Array.
// R2: smi-tagged argument count, may be zero.
__ BranchLink(StubCodeAllocateArray());
// R0: newly allocated array.
// R2: smi-tagged argument count, may be zero (was preserved by the stub).
__ Push(R0); // Array is in R0 and on top of stack.
__ AddImmediate(R1, FP,
target::frame_layout.param_end_from_fp * target::kWordSize);
__ AddImmediate(R3, R0, target::Array::data_offset() - kHeapObjectTag);
// Copy arguments from stack to array (starting at the end).
// R1: address just beyond last argument on stack.
// R3: address of first argument in array.
Label enter;
__ b(&enter);
Label loop;
__ Bind(&loop);
__ ldr(R8, Address(R1, target::kWordSize, Address::PreIndex));
// Generational barrier is needed, array is not necessarily in new space.
__ StoreIntoObject(R0, Address(R3, R2, LSL, 1), R8);
__ Bind(&enter);
__ subs(R2, R2, Operand(target::ToRawSmi(1))); // R2 is Smi.
__ b(&loop, PL);
}
// Used by eager and lazy deoptimization. Preserve result in R0 if necessary.
// This stub translates optimized frame into unoptimized frame. The optimized
// frame can contain values in registers and on stack, the unoptimized
// frame contains all values on stack.
// Deoptimization occurs in following steps:
// - Push all registers that can contain values.
// - Call C routine to copy the stack and saved registers into temporary buffer.
// - Adjust caller's frame to correct unoptimized frame size.
// - Fill the unoptimized frame.
// - Materialize objects that require allocation (e.g. Double instances).
// GC can occur only after frame is fully rewritten.
// Stack after EnterFrame(...) below:
// +------------------+
// | Saved PP | <- TOS
// +------------------+
// | Saved FP | <- FP of stub
// +------------------+
// | Saved LR | (deoptimization point)
// +------------------+
// | pc marker |
// +------------------+
// | Saved CODE_REG |
// +------------------+
// | ... | <- SP of optimized frame
//
// Parts of the code cannot GC, part of the code can GC.
static void GenerateDeoptimizationSequence(Assembler* assembler,
DeoptStubKind kind) {
// DeoptimizeCopyFrame expects a Dart frame, i.e. EnterDartFrame(0), but there
// is no need to set the correct PC marker or load PP, since they get patched.
__ EnterDartFrame(0);
__ LoadPoolPointer();
// The code in this frame may not cause GC. kDeoptimizeCopyFrameRuntimeEntry
// and kDeoptimizeFillFrameRuntimeEntry are leaf runtime calls.
const intptr_t saved_result_slot_from_fp =
target::frame_layout.first_local_from_fp + 1 -
(kNumberOfCpuRegisters - R0);
const intptr_t saved_exception_slot_from_fp =
target::frame_layout.first_local_from_fp + 1 -
(kNumberOfCpuRegisters - R0);
const intptr_t saved_stacktrace_slot_from_fp =
target::frame_layout.first_local_from_fp + 1 -
(kNumberOfCpuRegisters - R1);
// Result in R0 is preserved as part of pushing all registers below.
// Push registers in their enumeration order: lowest register number at
// lowest address.
for (intptr_t i = kNumberOfCpuRegisters - 1; i >= 0; --i) {
if (i == CODE_REG) {
// Save the original value of CODE_REG pushed before invoking this stub
// instead of the value used to call this stub.
__ ldr(IP, Address(FP, 2 * target::kWordSize));
__ Push(IP);
} else if (i == SP) {
// Push(SP) has unpredictable behavior.
__ mov(IP, Operand(SP));
__ Push(IP);
} else {
__ Push(static_cast<Register>(i));
}
}
if (TargetCPUFeatures::vfp_supported()) {
ASSERT(kFpuRegisterSize == 4 * target::kWordSize);
if (kNumberOfDRegisters > 16) {
__ vstmd(DB_W, SP, D16, kNumberOfDRegisters - 16);
__ vstmd(DB_W, SP, D0, 16);
} else {
__ vstmd(DB_W, SP, D0, kNumberOfDRegisters);
}
} else {
__ AddImmediate(SP, -kNumberOfFpuRegisters * kFpuRegisterSize);
}
__ mov(R0, Operand(SP)); // Pass address of saved registers block.
bool is_lazy =
(kind == kLazyDeoptFromReturn) || (kind == kLazyDeoptFromThrow);
__ mov(R1, Operand(is_lazy ? 1 : 0));
__ ReserveAlignedFrameSpace(0);
__ CallRuntime(kDeoptimizeCopyFrameRuntimeEntry, 2);
// Result (R0) is stack-size (FP - SP) in bytes.
if (kind == kLazyDeoptFromReturn) {
// Restore result into R1 temporarily.
__ ldr(R1, Address(FP, saved_result_slot_from_fp * target::kWordSize));
} else if (kind == kLazyDeoptFromThrow) {
// Restore result into R1 temporarily.
__ ldr(R1, Address(FP, saved_exception_slot_from_fp * target::kWordSize));
__ ldr(R2, Address(FP, saved_stacktrace_slot_from_fp * target::kWordSize));
}
__ RestoreCodePointer();
__ LeaveDartFrame();
__ sub(SP, FP, Operand(R0));
// DeoptimizeFillFrame expects a Dart frame, i.e. EnterDartFrame(0), but there
// is no need to set the correct PC marker or load PP, since they get patched.
__ EnterStubFrame();
__ mov(R0, Operand(FP)); // Get last FP address.
if (kind == kLazyDeoptFromReturn) {
__ Push(R1); // Preserve result as first local.
} else if (kind == kLazyDeoptFromThrow) {
__ Push(R1); // Preserve exception as first local.
__ Push(R2); // Preserve stacktrace as second local.
}
__ ReserveAlignedFrameSpace(0);
__ CallRuntime(kDeoptimizeFillFrameRuntimeEntry, 1); // Pass last FP in R0.
if (kind == kLazyDeoptFromReturn) {
// Restore result into R1.
__ ldr(R1, Address(FP, target::frame_layout.first_local_from_fp *
target::kWordSize));
} else if (kind == kLazyDeoptFromThrow) {
// Restore result into R1.
__ ldr(R1, Address(FP, target::frame_layout.first_local_from_fp *
target::kWordSize));
__ ldr(R2, Address(FP, (target::frame_layout.first_local_from_fp - 1) *
target::kWordSize));
}
// Code above cannot cause GC.
__ RestoreCodePointer();
__ LeaveStubFrame();
// Frame is fully rewritten at this point and it is safe to perform a GC.
// Materialize any objects that were deferred by FillFrame because they
// require allocation.
// Enter stub frame with loading PP. The caller's PP is not materialized yet.
__ EnterStubFrame();
if (kind == kLazyDeoptFromReturn) {
__ Push(R1); // Preserve result, it will be GC-d here.
} else if (kind == kLazyDeoptFromThrow) {
__ Push(R1); // Preserve exception, it will be GC-d here.
__ Push(R2); // Preserve stacktrace, it will be GC-d here.
}
__ PushObject(NullObject()); // Space for the result.
__ CallRuntime(kDeoptimizeMaterializeRuntimeEntry, 0);
// Result tells stub how many bytes to remove from the expression stack
// of the bottom-most frame. They were used as materialization arguments.
__ Pop(R2);
if (kind == kLazyDeoptFromReturn) {
__ Pop(R0); // Restore result.
} else if (kind == kLazyDeoptFromThrow) {
__ Pop(R1); // Restore stacktrace.
__ Pop(R0); // Restore exception.
}
__ LeaveStubFrame();
// Remove materialization arguments.
__ add(SP, SP, Operand(R2, ASR, kSmiTagSize));
// The caller is responsible for emitting the return instruction.
}
// R0: result, must be preserved
void StubCodeCompiler::GenerateDeoptimizeLazyFromReturnStub(
Assembler* assembler) {
// Push zap value instead of CODE_REG for lazy deopt.
__ LoadImmediate(IP, kZapCodeReg);
__ Push(IP);
// Return address for "call" to deopt stub.
WRITES_RETURN_ADDRESS_TO_LR(__ LoadImmediate(LR, kZapReturnAddress));
__ ldr(CODE_REG,
Address(THR, target::Thread::lazy_deopt_from_return_stub_offset()));
GenerateDeoptimizationSequence(assembler, kLazyDeoptFromReturn);
__ Ret();
}
// R0: exception, must be preserved
// R1: stacktrace, must be preserved
void StubCodeCompiler::GenerateDeoptimizeLazyFromThrowStub(
Assembler* assembler) {
// Push zap value instead of CODE_REG for lazy deopt.
__ LoadImmediate(IP, kZapCodeReg);
__ Push(IP);
// Return address for "call" to deopt stub.
WRITES_RETURN_ADDRESS_TO_LR(__ LoadImmediate(LR, kZapReturnAddress));
__ ldr(CODE_REG,
Address(THR, target::Thread::lazy_deopt_from_throw_stub_offset()));
GenerateDeoptimizationSequence(assembler, kLazyDeoptFromThrow);
__ Ret();
}
void StubCodeCompiler::GenerateDeoptimizeStub(Assembler* assembler) {
__ Push(CODE_REG);
__ ldr(CODE_REG, Address(THR, target::Thread::deoptimize_stub_offset()));
GenerateDeoptimizationSequence(assembler, kEagerDeopt);
__ Ret();
}
// R9: ICData/MegamorphicCache
static void GenerateNoSuchMethodDispatcherBody(Assembler* assembler) {
__ EnterStubFrame();
__ ldr(R4,
FieldAddress(R9, target::CallSiteData::arguments_descriptor_offset()));
// Load the receiver.
__ ldr(R2, FieldAddress(R4, target::ArgumentsDescriptor::size_offset()));
__ add(IP, FP, Operand(R2, LSL, 1)); // R2 is Smi.
__ ldr(R8, Address(IP, target::frame_layout.param_end_from_fp *
target::kWordSize));
__ LoadImmediate(IP, 0);
__ Push(IP); // Result slot.
__ Push(R8); // Receiver.
__ Push(R9); // ICData/MegamorphicCache.
__ Push(R4); // Arguments descriptor.
// Adjust arguments count.
__ ldr(R3,
FieldAddress(R4, target::ArgumentsDescriptor::type_args_len_offset()));
__ cmp(R3, Operand(0));
__ AddImmediate(R2, R2, target::ToRawSmi(1),
NE); // Include the type arguments.
// R2: Smi-tagged arguments array length.
PushArrayOfArguments(assembler);
const intptr_t kNumArgs = 4;
__ CallRuntime(kNoSuchMethodFromCallStubRuntimeEntry, kNumArgs);
__ Drop(4);
__ Pop(R0); // Return value.
__ LeaveStubFrame();
__ Ret();
}
static void GenerateDispatcherCode(Assembler* assembler,
Label* call_target_function) {
__ Comment("NoSuchMethodDispatch");
// When lazily generated invocation dispatchers are disabled, the
// miss-handler may return null.
__ CompareObject(R0, NullObject());
__ b(call_target_function, NE);
GenerateNoSuchMethodDispatcherBody(assembler);
}
// Input:
// R4 - arguments descriptor
// R9 - icdata/megamorphic_cache
void StubCodeCompiler::GenerateNoSuchMethodDispatcherStub(
Assembler* assembler) {
GenerateNoSuchMethodDispatcherBody(assembler);
}
// Called for inline allocation of arrays.
// Input parameters:
// LR: return address.
// R1: array element type (either NULL or an instantiated type).
// R2: array length as Smi (must be preserved).
// The newly allocated object is returned in R0.
void StubCodeCompiler::GenerateAllocateArrayStub(Assembler* assembler) {
if (!FLAG_use_slow_path) {
Label slow_case;
// Compute the size to be allocated, it is based on the array length
// and is computed as:
// RoundedAllocationSize(
// (array_length * kwordSize) + target::Array::header_size()).
__ mov(R3, Operand(R2)); // Array length.
// Check that length is a positive Smi.
__ tst(R3, Operand(kSmiTagMask));
__ b(&slow_case, NE);
__ cmp(R3, Operand(0));
__ b(&slow_case, LT);
// Check for maximum allowed length.
const intptr_t max_len =
target::ToRawSmi(target::Array::kMaxNewSpaceElements);
__ CompareImmediate(R3, max_len);
__ b(&slow_case, GT);
const intptr_t cid = kArrayCid;
NOT_IN_PRODUCT(__ LoadAllocationStatsAddress(R4, cid));
NOT_IN_PRODUCT(__ MaybeTraceAllocation(R4, &slow_case));
const intptr_t fixed_size_plus_alignment_padding =
target::Array::header_size() +
target::ObjectAlignment::kObjectAlignment - 1;
__ LoadImmediate(R9, fixed_size_plus_alignment_padding);
__ add(R9, R9, Operand(R3, LSL, 1)); // R3 is a Smi.
ASSERT(kSmiTagShift == 1);
__ bic(R9, R9, Operand(target::ObjectAlignment::kObjectAlignment - 1));
// R9: Allocation size.
// Potential new object start.
__ ldr(R0, Address(THR, target::Thread::top_offset()));
__ adds(R3, R0, Operand(R9)); // Potential next object start.
__ b(&slow_case, CS); // Branch if unsigned overflow.
// Check if the allocation fits into the remaining space.
// R0: potential new object start.
// R3: potential next object start.
// R9: allocation size.
__ ldr(TMP, Address(THR, target::Thread::end_offset()));
__ cmp(R3, Operand(TMP));
__ b(&slow_case, CS);
// Successfully allocated the object(s), now update top to point to
// next object start and initialize the object.
__ str(R3, Address(THR, target::Thread::top_offset()));
__ add(R0, R0, Operand(kHeapObjectTag));
// Initialize the tags.
// R0: new object start as a tagged pointer.
// R3: new object end address.
// R9: allocation size.
{
const intptr_t shift = target::UntaggedObject::kTagBitsSizeTagPos -
target::ObjectAlignment::kObjectAlignmentLog2;
__ CompareImmediate(R9, target::UntaggedObject::kSizeTagMaxSizeTag);
__ mov(R8, Operand(R9, LSL, shift), LS);
__ mov(R8, Operand(0), HI);
// Get the class index and insert it into the tags.
// R8: size and bit tags.
const uword tags =
target::MakeTagWordForNewSpaceObject(cid, /*instance_size=*/0);
__ LoadImmediate(TMP, tags);
__ orr(R8, R8, Operand(TMP));
__ str(R8,
FieldAddress(R0, target::Array::tags_offset())); // Store tags.
}
// R0: new object start as a tagged pointer.
// R3: new object end address.
// Store the type argument field.
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Array::type_arguments_offset()), R1);
// Set the length field.
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Array::length_offset()), R2);
// Initialize all array elements to raw_null.
// R0: new object start as a tagged pointer.
// R8, R9: null
// R4: iterator which initially points to the start of the variable
// data area to be initialized.
// R3: new object end address.
// R9: allocation size.
__ LoadObject(R8, NullObject());
__ mov(R9, Operand(R8));
__ AddImmediate(R4, R0, target::Array::header_size() - kHeapObjectTag);
__ InitializeFieldsNoBarrier(R0, R4, R3, R8, R9);
__ Ret(); // Returns the newly allocated object in R0.
// Unable to allocate the array using the fast inline code, just call
// into the runtime.
__ Bind(&slow_case);
}
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
__ LoadImmediate(TMP, 0);
// Setup space on stack for return value.
// Push array length as Smi and element type.
__ PushList((1 << R1) | (1 << R2) | (1 << IP));
__ CallRuntime(kAllocateArrayRuntimeEntry, 2);
// Pop arguments; result is popped in IP.
__ PopList((1 << R1) | (1 << R2) | (1 << IP)); // R2 is restored.
__ mov(R0, Operand(IP));
__ LeaveStubFrame();
// Write-barrier elimination might be enabled for this array (depending on the
// array length). To be sure we will check if the allocated object is in old
// space and if so call a leaf runtime to add it to the remembered set.
EnsureIsNewOrRemembered(assembler);
__ Ret();
}
// Called for allocation of Mint.
void StubCodeCompiler::GenerateAllocateMintSharedWithFPURegsStub(
Assembler* assembler) {
// For test purpose call allocation stub without inline allocation attempt.
if (!FLAG_use_slow_path) {
Label slow_case;
__ TryAllocate(compiler::MintClass(), &slow_case,
AllocateMintABI::kResultReg, AllocateMintABI::kTempReg);
__ Ret();
__ Bind(&slow_case);
}
COMPILE_ASSERT(AllocateMintABI::kResultReg ==
SharedSlowPathStubABI::kResultReg);
GenerateSharedStub(assembler, /*save_fpu_registers=*/true,
&kAllocateMintRuntimeEntry,
target::Thread::allocate_mint_with_fpu_regs_stub_offset(),
/*allow_return=*/true,
/*store_runtime_result_in_result_register=*/true);
}
// Called for allocation of Mint.
void StubCodeCompiler::GenerateAllocateMintSharedWithoutFPURegsStub(
Assembler* assembler) {
// For test purpose call allocation stub without inline allocation attempt.
if (!FLAG_use_slow_path) {
Label slow_case;
__ TryAllocate(compiler::MintClass(), &slow_case,
AllocateMintABI::kResultReg, AllocateMintABI::kTempReg);
__ Ret();
__ Bind(&slow_case);
}
COMPILE_ASSERT(AllocateMintABI::kResultReg ==
SharedSlowPathStubABI::kResultReg);
GenerateSharedStub(
assembler, /*save_fpu_registers=*/false, &kAllocateMintRuntimeEntry,
target::Thread::allocate_mint_without_fpu_regs_stub_offset(),
/*allow_return=*/true,
/*store_runtime_result_in_result_register=*/true);
}
// Called when invoking Dart code from C++ (VM code).
// Input parameters:
// LR : points to return address.
// R0 : code object of the Dart function to call.
// R1 : arguments descriptor array.
// R2 : arguments array.
// R3 : current thread.
void StubCodeCompiler::GenerateInvokeDartCodeStub(Assembler* assembler) {
READS_RETURN_ADDRESS_FROM_LR(__ Push(LR)); // Marker for the profiler.
SPILLS_LR_TO_FRAME(__ EnterFrame((1 << FP) | (1 << LR), 0));
// Push code object to PC marker slot.
__ ldr(IP, Address(R3, target::Thread::invoke_dart_code_stub_offset()));
__ Push(IP);
__ PushNativeCalleeSavedRegisters();
// Set up THR, which caches the current thread in Dart code.
if (THR != R3) {
__ mov(THR, Operand(R3));
}
#if defined(USING_SHADOW_CALL_STACK)
#error Unimplemented
#endif
// Save the current VMTag on the stack.
__ LoadFromOffset(R9, THR, target::Thread::vm_tag_offset());
__ Push(R9);
// Save top resource and top exit frame info. Use R4-6 as temporary registers.
// StackFrameIterator reads the top exit frame info saved in this frame.
__ LoadFromOffset(R4, THR, target::Thread::top_resource_offset());
__ Push(R4);
__ LoadImmediate(R8, 0);
__ StoreToOffset(R8, THR, target::Thread::top_resource_offset());
__ LoadFromOffset(R8, THR, target::Thread::exit_through_ffi_offset());
__ Push(R8);
__ LoadImmediate(R8, 0);
__ StoreToOffset(R8, THR, target::Thread::exit_through_ffi_offset());
__ LoadFromOffset(R9, THR, target::Thread::top_exit_frame_info_offset());
__ StoreToOffset(R8, THR, target::Thread::top_exit_frame_info_offset());
// target::frame_layout.exit_link_slot_from_entry_fp must be kept in sync
// with the code below.
#if defined(TARGET_OS_MACOS) || defined(TARGET_OS_MACOS_IOS)
ASSERT(target::frame_layout.exit_link_slot_from_entry_fp == -27);
#else
ASSERT(target::frame_layout.exit_link_slot_from_entry_fp == -28);
#endif
__ Push(R9);
__ EmitEntryFrameVerification(R9);
// Mark that the thread is executing Dart code. Do this after initializing the
// exit link for the profiler.
__ LoadImmediate(R9, VMTag::kDartTagId);
__ StoreToOffset(R9, THR, target::Thread::vm_tag_offset());
// Load arguments descriptor array into R4, which is passed to Dart code.
__ ldr(R4, Address(R1, target::VMHandles::kOffsetOfRawPtrInHandle));
// Load number of arguments into R9 and adjust count for type arguments.
__ ldr(R3,
FieldAddress(R4, target::ArgumentsDescriptor::type_args_len_offset()));
__ ldr(R9, FieldAddress(R4, target::ArgumentsDescriptor::count_offset()));
__ cmp(R3, Operand(0));
__ AddImmediate(R9, R9, target::ToRawSmi(1),
NE); // Include the type arguments.
__ SmiUntag(R9);
// Compute address of 'arguments array' data area into R2.
__ ldr(R2, Address(R2, target::VMHandles::kOffsetOfRawPtrInHandle));
__ AddImmediate(R2, target::Array::data_offset() - kHeapObjectTag);
// Set up arguments for the Dart call.
Label push_arguments;
Label done_push_arguments;
__ CompareImmediate(R9, 0); // check if there are arguments.
__ b(&done_push_arguments, EQ);
__ LoadImmediate(R1, 0);
__ Bind(&push_arguments);
__ ldr(R3, Address(R2));
__ Push(R3);
__ AddImmediate(R2, target::kWordSize);
__ AddImmediate(R1, 1);
__ cmp(R1, Operand(R9));
__ b(&push_arguments, LT);
__ Bind(&done_push_arguments);
// Call the Dart code entrypoint.
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ SetupGlobalPoolAndDispatchTable();
} else {
__ LoadImmediate(PP, 0); // GC safe value into PP.
}
__ ldr(CODE_REG, Address(R0, target::VMHandles::kOffsetOfRawPtrInHandle));
__ ldr(R0, FieldAddress(CODE_REG, target::Code::entry_point_offset()));
__ blx(R0); // R4 is the arguments descriptor array.
// Get rid of arguments pushed on the stack.
__ AddImmediate(
SP, FP,
target::frame_layout.exit_link_slot_from_entry_fp * target::kWordSize);
// Restore the saved top exit frame info and top resource back into the
// Isolate structure. Uses R9 as a temporary register for this.
__ Pop(R9);
__ StoreToOffset(R9, THR, target::Thread::top_exit_frame_info_offset());
__ Pop(R9);
__ StoreToOffset(R9, THR, target::Thread::exit_through_ffi_offset());
__ Pop(R9);
__ StoreToOffset(R9, THR, target::Thread::top_resource_offset());
// Restore the current VMTag from the stack.
__ Pop(R4);
__ StoreToOffset(R4, THR, target::Thread::vm_tag_offset());
#if defined(USING_SHADOW_CALL_STACK)
#error Unimplemented
#endif
__ PopNativeCalleeSavedRegisters();
__ set_constant_pool_allowed(false);
// Restore the frame pointer and return.
RESTORES_LR_FROM_FRAME(__ LeaveFrame((1 << FP) | (1 << LR)));
__ Drop(1);
__ Ret();
}
// Helper to generate space allocation of context stub.
// This does not initialise the fields of the context.
// Input:
// R1: number of context variables.
// Output:
// R0: new allocated Context object.
// Clobbered:
// R2, R3, R8, R9
static void GenerateAllocateContext(Assembler* assembler, Label* slow_case) {
// First compute the rounded instance size.
// R1: number of context variables.
const intptr_t fixed_size_plus_alignment_padding =
target::Context::header_size() +
target::ObjectAlignment::kObjectAlignment - 1;
__ LoadImmediate(R2, fixed_size_plus_alignment_padding);
__ add(R2, R2, Operand(R1, LSL, 2));
ASSERT(kSmiTagShift == 1);
__ bic(R2, R2, Operand(target::ObjectAlignment::kObjectAlignment - 1));
NOT_IN_PRODUCT(__ LoadAllocationStatsAddress(R8, kContextCid));
NOT_IN_PRODUCT(__ MaybeTraceAllocation(R8, slow_case));
// Now allocate the object.
// R1: number of context variables.
// R2: object size.
__ ldr(R0, Address(THR, target::Thread::top_offset()));
__ add(R3, R2, Operand(R0));
// Check if the allocation fits into the remaining space.
// R0: potential new object.
// R1: number of context variables.
// R2: object size.
// R3: potential next object start.
__ ldr(IP, Address(THR, target::Thread::end_offset()));
__ cmp(R3, Operand(IP));
__ b(slow_case, CS); // Branch if unsigned higher or equal.
// Successfully allocated the object, now update top to point to
// next object start and initialize the object.
// R0: new object start (untagged).
// R1: number of context variables.
// R2: object size.
// R3: next object start.
__ str(R3, Address(THR, target::Thread::top_offset()));
__ add(R0, R0, Operand(kHeapObjectTag));
// Calculate the size tag.
// R0: new object (tagged).
// R1: number of context variables.
// R2: object size.
// R3: next object start.
const intptr_t shift = target::UntaggedObject::kTagBitsSizeTagPos -
target::ObjectAlignment::kObjectAlignmentLog2;
__ CompareImmediate(R2, target::UntaggedObject::kSizeTagMaxSizeTag);
// If no size tag overflow, shift R2 left, else set R2 to zero.
__ mov(R9, Operand(R2, LSL, shift), LS);
__ mov(R9, Operand(0), HI);
// Get the class index and insert it into the tags.
// R9: size and bit tags.
const uword tags =
target::MakeTagWordForNewSpaceObject(kContextCid, /*instance_size=*/0);
__ LoadImmediate(IP, tags);
__ orr(R9, R9, Operand(IP));
__ str(R9, FieldAddress(R0, target::Object::tags_offset()));
// Setup up number of context variables field.
// R0: new object.
// R1: number of context variables as integer value (not object).
// R2: object size.
// R3: next object start.
__ str(R1, FieldAddress(R0, target::Context::num_variables_offset()));
}
// Called for inline allocation of contexts.
// Input:
// R1: number of context variables.
// Output:
// R0: new allocated Context object.
// Clobbered:
// Potentially any since is can go to runtime.
void StubCodeCompiler::GenerateAllocateContextStub(Assembler* assembler) {
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label slow_case;
GenerateAllocateContext(assembler, &slow_case);
// Setup the parent field.
// R0: new object.
// R2: object size.
// R3: next object start.
__ LoadObject(R8, NullObject());
__ MoveRegister(R9, R8); // Needed for InitializeFieldsNoBarrier.
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Context::parent_offset()), R8);
// Initialize the context variables.
// R0: new object.
// R2: object size.
// R3: next object start.
// R8, R9: raw null.
__ AddImmediate(R1, R0,
target::Context::variable_offset(0) - kHeapObjectTag);
__ InitializeFieldsNoBarrier(R0, R1, R3, R8, R9);
// Done allocating and initializing the context.
// R0: new object.
__ Ret();
__ Bind(&slow_case);
}
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
// Setup space on stack for return value.
__ LoadImmediate(R2, 0);
__ SmiTag(R1);
__ PushList((1 << R1) | (1 << R2));
__ CallRuntime(kAllocateContextRuntimeEntry, 1); // Allocate context.
__ Drop(1); // Pop number of context variables argument.
__ Pop(R0); // Pop the new context object.
// Write-barrier elimination might be enabled for this context (depending on
// the size). To be sure we will check if the allocated object is in old
// space and if so call a leaf runtime to add it to the remembered set.
EnsureIsNewOrRemembered(assembler, /*preserve_registers=*/false);
// R0: new object
// Restore the frame pointer.
__ LeaveStubFrame();
__ Ret();
}
// Called for clone of contexts.
// Input:
// R4: context variable to clone.
// Output:
// R0: new allocated Context object.
// Clobbered:
// Potentially any since it can go to runtime.
void StubCodeCompiler::GenerateCloneContextStub(Assembler* assembler) {
{
Label slow_case;
// Load num. variable in the existing context.
__ ldr(R1, FieldAddress(R4, target::Context::num_variables_offset()));
GenerateAllocateContext(assembler, &slow_case);
// Load parent in the existing context.
__ ldr(R2, FieldAddress(R4, target::Context::parent_offset()));
// Setup the parent field.
// R0: new object.
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Context::parent_offset()), R2);
// Clone the context variables.
// R0: new object.
// R1: number of context variables.
{
Label loop, done;
__ AddImmediate(R2, R0,
target::Context::variable_offset(0) - kHeapObjectTag);
__ AddImmediate(R3, R4,
target::Context::variable_offset(0) - kHeapObjectTag);
__ Bind(&loop);
__ subs(R1, R1, Operand(1));
__ b(&done, MI);
__ ldr(R9, Address(R3, R1, LSL, target::kWordSizeLog2));
__ str(R9, Address(R2, R1, LSL, target::kWordSizeLog2));
__ b(&loop, NE); // Loop if R1 not zero.
__ Bind(&done);
}
// Done allocating and initializing the context.
// R0: new object.
__ Ret();
__ Bind(&slow_case);
}
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
// Setup space on stack for return value.
__ LoadImmediate(R0, 0);
__ PushRegisterPair(R4, R0);
__ CallRuntime(kCloneContextRuntimeEntry, 1); // Clone context.
// R4: Pop number of context variables argument.
// R0: Pop the new context object.
__ PopRegisterPair(R4, R0);
// Write-barrier elimination might be enabled for this context (depending on
// the size). To be sure we will check if the allocated object is in old
// space and if so call a leaf runtime to add it to the remembered set.
EnsureIsNewOrRemembered(assembler, /*preserve_registers=*/false);
// R0: new object
// Restore the frame pointer.
__ LeaveStubFrame();
__ Ret();
}
void StubCodeCompiler::GenerateWriteBarrierWrappersStub(Assembler* assembler) {
for (intptr_t i = 0; i < kNumberOfCpuRegisters; ++i) {
if ((kDartAvailableCpuRegs & (1 << i)) == 0) continue;
Register reg = static_cast<Register>(i);
intptr_t start = __ CodeSize();
SPILLS_LR_TO_FRAME(__ PushList((1 << LR) | (1 << kWriteBarrierObjectReg)));
__ mov(kWriteBarrierObjectReg, Operand(reg));
__ Call(Address(THR, target::Thread::write_barrier_entry_point_offset()));
RESTORES_LR_FROM_FRAME(
__ PopList((1 << LR) | (1 << kWriteBarrierObjectReg)));
READS_RETURN_ADDRESS_FROM_LR(__ bx(LR));
intptr_t end = __ CodeSize();
RELEASE_ASSERT(end - start == kStoreBufferWrapperSize);
}
}
// Helper stub to implement Assembler::StoreIntoObject.
// Input parameters:
// R1: Object (old)
// R0: Value (old or new)
// R9: Slot
// If R0 is new, add R1 to the store buffer. Otherwise R0 is old, mark R0
// and add it to the mark list.
COMPILE_ASSERT(kWriteBarrierObjectReg == R1);
COMPILE_ASSERT(kWriteBarrierValueReg == R0);
COMPILE_ASSERT(kWriteBarrierSlotReg == R9);
static void GenerateWriteBarrierStubHelper(Assembler* assembler,
Address stub_code,
bool cards) {
Label add_to_mark_stack, remember_card;
__ tst(R0, Operand(1 << target::ObjectAlignment::kNewObjectBitPosition));
__ b(&add_to_mark_stack, ZERO);
if (cards) {
__ ldr(TMP, FieldAddress(R1, target::Object::tags_offset()));
__ tst(TMP, Operand(1 << target::UntaggedObject::kCardRememberedBit));
__ b(&remember_card, NOT_ZERO);
} else {
#if defined(DEBUG)
Label ok;
__ ldr(TMP, FieldAddress(R1, target::Object::tags_offset()));
__ tst(TMP, Operand(1 << target::UntaggedObject::kCardRememberedBit));
__ b(&ok, ZERO);
__ Stop("Wrong barrier");
__ Bind(&ok);
#endif
}
// Save values being destroyed.
__ PushList((1 << R2) | (1 << R3) | (1 << R4));
// Atomically set the remembered bit of the object header.
ASSERT(target::Object::tags_offset() == 0);
__ sub(R3, R1, Operand(kHeapObjectTag));
// R3: Untagged address of header word (ldrex/strex do not support offsets).
Label retry;
__ Bind(&retry);
__ ldrex(R2, R3);
__ bic(R2, R2, Operand(1 << target::UntaggedObject::kOldAndNotRememberedBit));
__ strex(R4, R2, R3);
__ cmp(R4, Operand(1));
__ b(&retry, EQ);
// Load the StoreBuffer block out of the thread. Then load top_ out of the
// StoreBufferBlock and add the address to the pointers_.
__ ldr(R4, Address(THR, target::Thread::store_buffer_block_offset()));
__ ldr(R2, Address(R4, target::StoreBufferBlock::top_offset()));
__ add(R3, R4, Operand(R2, LSL, target::kWordSizeLog2));
__ str(R1, Address(R3, target::StoreBufferBlock::pointers_offset()));
// Increment top_ and check for overflow.
// R2: top_.
// R4: StoreBufferBlock.
Label overflow;
__ add(R2, R2, Operand(1));
__ str(R2, Address(R4, target::StoreBufferBlock::top_offset()));
__ CompareImmediate(R2, target::StoreBufferBlock::kSize);
// Restore values.
__ PopList((1 << R2) | (1 << R3) | (1 << R4));
__ b(&overflow, EQ);
__ Ret();
// Handle overflow: Call the runtime leaf function.
__ Bind(&overflow);
// Setup frame, push callee-saved registers.
__ Push(CODE_REG);
__ ldr(CODE_REG, stub_code);
__ EnterCallRuntimeFrame(0 * target::kWordSize);
__ mov(R0, Operand(THR));
__ CallRuntime(kStoreBufferBlockProcessRuntimeEntry, 1);
// Restore callee-saved registers, tear down frame.
__ LeaveCallRuntimeFrame();
__ Pop(CODE_REG);
__ Ret();
__ Bind(&add_to_mark_stack);
__ PushList((1 << R2) | (1 << R3) | (1 << R4)); // Spill.
Label marking_retry, lost_race, marking_overflow;
// Atomically clear kOldAndNotMarkedBit.
ASSERT(target::Object::tags_offset() == 0);
__ sub(R3, R0, Operand(kHeapObjectTag));
// R3: Untagged address of header word (ldrex/strex do not support offsets).
__ Bind(&marking_retry);
__ ldrex(R2, R3);
__ tst(R2, Operand(1 << target::UntaggedObject::kOldAndNotMarkedBit));
__ b(&lost_race, ZERO);
__ bic(R2, R2, Operand(1 << target::UntaggedObject::kOldAndNotMarkedBit));
__ strex(R4, R2, R3);
__ cmp(R4, Operand(1));
__ b(&marking_retry, EQ);
__ ldr(R4, Address(THR, target::Thread::marking_stack_block_offset()));
__ ldr(R2, Address(R4, target::MarkingStackBlock::top_offset()));
__ add(R3, R4, Operand(R2, LSL, target::kWordSizeLog2));
__ str(R0, Address(R3, target::MarkingStackBlock::pointers_offset()));
__ add(R2, R2, Operand(1));
__ str(R2, Address(R4, target::MarkingStackBlock::top_offset()));
__ CompareImmediate(R2, target::MarkingStackBlock::kSize);
__ PopList((1 << R4) | (1 << R2) | (1 << R3)); // Unspill.
__ b(&marking_overflow, EQ);
__ Ret();
__ Bind(&marking_overflow);
__ Push(CODE_REG);
__ ldr(CODE_REG, stub_code);
__ EnterCallRuntimeFrame(0 * target::kWordSize);
__ mov(R0, Operand(THR));
__ CallRuntime(kMarkingStackBlockProcessRuntimeEntry, 1);
__ LeaveCallRuntimeFrame();
__ Pop(CODE_REG);
__ Ret();
__ Bind(&lost_race);
__ PopList((1 << R2) | (1 << R3) | (1 << R4)); // Unspill.
__ Ret();
if (cards) {
Label remember_card_slow;
// Get card table.
__ Bind(&remember_card);
__ AndImmediate(TMP, R1, target::kOldPageMask); // OldPage.
__ ldr(TMP,
Address(TMP, target::OldPage::card_table_offset())); // Card table.
__ cmp(TMP, Operand(0));
__ b(&remember_card_slow, EQ);
// Dirty the card.
__ AndImmediate(TMP, R1, target::kOldPageMask); // OldPage.
__ sub(R9, R9, Operand(TMP)); // Offset in page.
__ ldr(TMP,
Address(TMP, target::OldPage::card_table_offset())); // Card table.
__ add(TMP, TMP,
Operand(R9, LSR,
target::OldPage::kBytesPerCardLog2)); // Card address.
__ strb(R1,
Address(TMP, 0)); // Low byte of R0 is non-zero from object tag.
__ Ret();
// Card table not yet allocated.
__ Bind(&remember_card_slow);
__ Push(CODE_REG);
__ Push(R0);
__ Push(R1);
__ ldr(CODE_REG, stub_code);
__ mov(R0, Operand(R1)); // Arg0 = Object
__ mov(R1, Operand(R9)); // Arg1 = Slot
__ EnterCallRuntimeFrame(0);
__ CallRuntime(kRememberCardRuntimeEntry, 2);
__ LeaveCallRuntimeFrame();
__ Pop(R1);
__ Pop(R0);
__ Pop(CODE_REG);
__ Ret();
}
}
void StubCodeCompiler::GenerateWriteBarrierStub(Assembler* assembler) {
GenerateWriteBarrierStubHelper(
assembler, Address(THR, target::Thread::write_barrier_code_offset()),
false);
}
void StubCodeCompiler::GenerateArrayWriteBarrierStub(Assembler* assembler) {
GenerateWriteBarrierStubHelper(
assembler,
Address(THR, target::Thread::array_write_barrier_code_offset()), true);
}
static void GenerateAllocateObjectHelper(Assembler* assembler,
bool is_cls_parameterized) {
const Register kInstanceReg = R0;
// R1
const Register kTagsReg = R2;
// kAllocationStubTypeArgumentsReg = R3
{
Label slow_case;
const Register kNewTopReg = R8;
// Bump allocation.
{
const Register kEndReg = R1;
const Register kInstanceSizeReg = R9;
__ ExtractInstanceSizeFromTags(kInstanceSizeReg, kTagsReg);
// Load two words from Thread::top: top and end.
// kInstanceReg: potential next object start.
__ ldrd(kInstanceReg, kEndReg, THR, target::Thread::top_offset());
__ add(kNewTopReg, kInstanceReg, Operand(kInstanceSizeReg));
__ CompareRegisters(kEndReg, kNewTopReg);
__ b(&slow_case, UNSIGNED_LESS_EQUAL);
// Successfully allocated the object, now update top to point to
// next object start and store the class in the class field of object.
__ str(kNewTopReg, Address(THR, target::Thread::top_offset()));
} // kEndReg = R1, kInstanceSizeReg = R9
// Tags.
__ str(kTagsReg, Address(kInstanceReg, target::Object::tags_offset()));
// Initialize the remaining words of the object.
{
const Register kFieldReg = R1;
const Register kNullReg = R9;
__ LoadObject(kNullReg, NullObject());
__ AddImmediate(kFieldReg, kInstanceReg,
target::Instance::first_field_offset());
Label done, init_loop;
__ Bind(&init_loop);
__ CompareRegisters(kFieldReg, kNewTopReg);
__ b(&done, UNSIGNED_GREATER_EQUAL);
__ str(kNullReg,
Address(kFieldReg, target::kWordSize, Address::PostIndex));
__ b(&init_loop);
__ Bind(&done);
} // kFieldReg = R1, kNullReg = R9
// Store parameterized type.
if (is_cls_parameterized) {
Label not_parameterized_case;
const Register kClsIdReg = R2;
const Register kTypeOffestReg = R9;
__ ExtractClassIdFromTags(kClsIdReg, kTagsReg);
// Load class' type_arguments_field offset in words.
__ LoadClassById(kTypeOffestReg, kClsIdReg);
__ ldr(
kTypeOffestReg,
FieldAddress(kTypeOffestReg,
target::Class::
host_type_arguments_field_offset_in_words_offset()));
// Set the type arguments in the new object.
__ StoreIntoObjectNoBarrier(
kInstanceReg,
Address(kInstanceReg, kTypeOffestReg, LSL, target::kWordSizeLog2),
kAllocationStubTypeArgumentsReg);
__ Bind(&not_parameterized_case);
} // kClsIdReg = R1, kTypeOffestReg = R9
__ AddImmediate(kInstanceReg, kInstanceReg, kHeapObjectTag);
__ Ret();
__ Bind(&slow_case);
} // kNewTopReg = R8
// Fall back on slow case:
{
const Register kStubReg = R8;
if (!is_cls_parameterized) {
__ LoadObject(kAllocationStubTypeArgumentsReg, NullObject());
}
// Tail call to generic allocation stub.
__ ldr(kStubReg,
Address(THR,
target::Thread::allocate_object_slow_entry_point_offset()));
__ bx(kStubReg);
} // kStubReg = R8
}
// Called for inline allocation of objects (any class).
void StubCodeCompiler::GenerateAllocateObjectStub(Assembler* assembler) {
GenerateAllocateObjectHelper(assembler, /*is_cls_parameterized=*/false);
}
void StubCodeCompiler::GenerateAllocateObjectParameterizedStub(
Assembler* assembler) {
GenerateAllocateObjectHelper(assembler, /*is_cls_parameterized=*/true);
}
void StubCodeCompiler::GenerateAllocateObjectSlowStub(Assembler* assembler) {
const Register kInstanceReg = R0;
const Register kClsReg = R1;
const Register kTagsReg = R2;
// kAllocationStubTypeArgumentsReg = R3
if (!FLAG_use_bare_instructions) {
__ ldr(CODE_REG,
Address(THR, target::Thread::call_to_runtime_stub_offset()));
}
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
__ ExtractClassIdFromTags(kInstanceReg, kTagsReg);
__ LoadClassById(kClsReg, kInstanceReg);
__ LoadObject(kInstanceReg, NullObject());
// Pushes result slot, then parameter class.
__ PushRegisterPair(kClsReg, kInstanceReg);
// Should be Object::null() if class is non-parameterized.
__ Push(kAllocationStubTypeArgumentsReg);
__ CallRuntime(kAllocateObjectRuntimeEntry, 2);
// Load result off the stack into result register.
__ ldr(kInstanceReg, Address(SP, 2 * target::kWordSize));
// Write-barrier elimination is enabled for [cls] and we therefore need to
// ensure that the object is in new-space or has remembered bit set.
EnsureIsNewOrRemembered(assembler, /*preserve_registers=*/false);
__ LeaveDartFrameAndReturn();
}
// Called for inline allocation of objects.
void StubCodeCompiler::GenerateAllocationStubForClass(
Assembler* assembler,
UnresolvedPcRelativeCalls* unresolved_calls,
const Class& cls,
const Code& allocate_object,
const Code& allocat_object_parametrized) {
classid_t cls_id = target::Class::GetId(cls);
ASSERT(cls_id != kIllegalCid);
RELEASE_ASSERT(AllocateObjectInstr::WillAllocateNewOrRemembered(cls));
// The generated code is different if the class is parameterized.
const bool is_cls_parameterized = target::Class::NumTypeArguments(cls) > 0;
ASSERT(!is_cls_parameterized || target::Class::TypeArgumentsFieldOffset(
cls) != target::Class::kNoTypeArguments);
const intptr_t instance_size = target::Class::GetInstanceSize(cls);
ASSERT(instance_size > 0);
RELEASE_ASSERT(target::Heap::IsAllocatableInNewSpace(instance_size));
const uword tags =
target::MakeTagWordForNewSpaceObject(cls_id, instance_size);
// Note: Keep in sync with helper function.
// kInstanceReg = R0
const Register kTagsReg = R2;
// kAllocationStubTypeArgumentsReg = R3
__ LoadImmediate(kTagsReg, tags);
if (!FLAG_use_slow_path && FLAG_inline_alloc &&
!target::Class::TraceAllocation(cls) &&
target::SizeFitsInSizeTag(instance_size)) {
if (is_cls_parameterized) {
// TODO(41974): Assign all allocation stubs to the root loading unit?
if (false &&
!IsSameObject(NullObject(),
CastHandle<Object>(allocat_object_parametrized))) {
__ GenerateUnRelocatedPcRelativeTailCall();
unresolved_calls->Add(new UnresolvedPcRelativeCall(
__ CodeSize(), allocat_object_parametrized, /*is_tail_call=*/true));
} else {
__ ldr(PC,
Address(THR,
target::Thread::
allocate_object_parameterized_entry_point_offset()));
}
} else {
// TODO(41974): Assign all allocation stubs to the root loading unit?
if (false &&
!IsSameObject(NullObject(), CastHandle<Object>(allocate_object))) {
__ GenerateUnRelocatedPcRelativeTailCall();
unresolved_calls->Add(new UnresolvedPcRelativeCall(
__ CodeSize(), allocate_object, /*is_tail_call=*/true));
} else {
__ ldr(
PC,
Address(THR, target::Thread::allocate_object_entry_point_offset()));
}
}
} else {
if (!is_cls_parameterized) {
__ LoadObject(kAllocationStubTypeArgumentsReg, NullObject());
}
__ ldr(PC,
Address(THR,
target::Thread::allocate_object_slow_entry_point_offset()));
}
}
// Called for invoking "dynamic noSuchMethod(Invocation invocation)" function
// from the entry code of a dart function after an error in passed argument
// name or number is detected.
// Input parameters:
// LR : return address.
// SP : address of last argument.
// R4: arguments descriptor array.
void StubCodeCompiler::GenerateCallClosureNoSuchMethodStub(
Assembler* assembler) {
__ EnterStubFrame();
// Load the receiver.
__ ldr(R2, FieldAddress(R4, target::ArgumentsDescriptor::count_offset()));
__ add(IP, FP, Operand(R2, LSL, 1)); // R2 is Smi.
__ ldr(R8, Address(IP, target::frame_layout.param_end_from_fp *
target::kWordSize));
// Load the function.
__ ldr(R6, FieldAddress(R8, target::Closure::function_offset()));
// Push space for the return value.
// Push the receiver.
// Push arguments descriptor array.
__ LoadImmediate(IP, 0);
__ PushList((1 << R4) | (1 << R6) | (1 << R8) | (1 << IP));
// Adjust arguments count.
__ ldr(R3,
FieldAddress(R4, target::ArgumentsDescriptor::type_args_len_offset()));
__ cmp(R3, Operand(0));
__ AddImmediate(R2, R2, target::ToRawSmi(1),
NE); // Include the type arguments.
// R2: Smi-tagged arguments array length.
PushArrayOfArguments(assembler);
const intptr_t kNumArgs = 4;
__ CallRuntime(kNoSuchMethodFromPrologueRuntimeEntry, kNumArgs);
// noSuchMethod on closures always throws an error, so it will never return.
__ bkpt(0);
}
// R8: function object.
// R9: inline cache data object.
// Cannot use function object from ICData as it may be the inlined
// function and not the top-scope function.
void StubCodeCompiler::GenerateOptimizedUsageCounterIncrement(
Assembler* assembler) {
Register ic_reg = R9;
Register func_reg = R8;
if (FLAG_precompiled_mode) {
__ Breakpoint();
return;
}
if (FLAG_trace_optimized_ic_calls) {
__ EnterStubFrame();
__ PushList((1 << R9) | (1 << R8)); // Preserve.
__ Push(ic_reg); // Argument.
__ Push(func_reg); // Argument.
__ CallRuntime(kTraceICCallRuntimeEntry, 2);
__ Drop(2); // Discard argument;
__ PopList((1 << R9) | (1 << R8)); // Restore.
__ LeaveStubFrame();
}
__ ldr(TMP, FieldAddress(func_reg, target::Function::usage_counter_offset()));
__ add(TMP, TMP, Operand(1));
__ str(TMP, FieldAddress(func_reg, target::Function::usage_counter_offset()));
}
// Loads function into 'temp_reg'.
void StubCodeCompiler::GenerateUsageCounterIncrement(Assembler* assembler,
Register temp_reg) {
if (FLAG_precompiled_mode) {
__ Breakpoint();
return;
}
if (FLAG_optimization_counter_threshold >= 0) {
Register ic_reg = R9;
Register func_reg = temp_reg;
ASSERT(temp_reg == R8);
__ Comment("Increment function counter");
__ ldr(func_reg, FieldAddress(ic_reg, target::ICData::owner_offset()));
__ ldr(TMP,
FieldAddress(func_reg, target::Function::usage_counter_offset()));
__ add(TMP, TMP, Operand(1));
__ str(TMP,
FieldAddress(func_reg, target::Function::usage_counter_offset()));
}
}
// Note: R9 must be preserved.
// Attempt a quick Smi operation for known operations ('kind'). The ICData
// must have been primed with a Smi/Smi check that will be used for counting
// the invocations.
static void EmitFastSmiOp(Assembler* assembler,
Token::Kind kind,
intptr_t num_args,
Label* not_smi_or_overflow) {
__ Comment("Fast Smi op");
__ ldr(R0, Address(SP, 1 * target::kWordSize)); // Left.
__ ldr(R1, Address(SP, 0 * target::kWordSize)); // Right.
__ orr(TMP, R0, Operand(R1));
__ tst(TMP, Operand(kSmiTagMask));
__ b(not_smi_or_overflow, NE);
switch (kind) {
case Token::kADD: {
__ adds(R0, R1, Operand(R0)); // Adds.
__ b(not_smi_or_overflow, VS); // Branch if overflow.
break;
}
case Token::kLT: {
__ cmp(R0, Operand(R1));
__ LoadObject(R0, CastHandle<Object>(TrueObject()), LT);
__ LoadObject(R0, CastHandle<Object>(FalseObject()), GE);
break;
}
case Token::kEQ: {
__ cmp(R0, Operand(R1));
__ LoadObject(R0, CastHandle<Object>(TrueObject()), EQ);
__ LoadObject(R0, CastHandle<Object>(FalseObject()), NE);
break;
}
default:
UNIMPLEMENTED();
}
// R9: IC data object (preserved).
__ ldr(R8, FieldAddress(R9, target::ICData::entries_offset()));
// R8: ic_data_array with check entries: classes and target functions.
__ AddImmediate(R8, target::Array::data_offset() - kHeapObjectTag);
// R8: points directly to the first ic data array element.
#if defined(DEBUG)
// Check that first entry is for Smi/Smi.
Label error, ok;
const intptr_t imm_smi_cid = target::ToRawSmi(kSmiCid);
__ ldr(R1, Address(R8, 0));
__ CompareImmediate(R1, imm_smi_cid);
__ b(&error, NE);
__ ldr(R1, Address(R8, target::kWordSize));
__ CompareImmediate(R1, imm_smi_cid);
__ b(&ok, EQ);
__ Bind(&error);
__ Stop("Incorrect IC data");
__ Bind(&ok);
#endif
if (FLAG_optimization_counter_threshold >= 0) {
// Update counter, ignore overflow.
const intptr_t count_offset =
target::ICData::CountIndexFor(num_args) * target::kWordSize;
__ LoadFromOffset(R1, R8, count_offset);
__ adds(R1, R1, Operand(target::ToRawSmi(1)));
__ StoreIntoSmiField(Address(R8, count_offset), R1);
}
__ Ret();
}
// Saves the offset of the target entry-point (from the Function) into R3.
//
// Must be the first code generated, since any code before will be skipped in
// the unchecked entry-point.
static void GenerateRecordEntryPoint(Assembler* assembler) {
Label done;
__ mov(R3, Operand(target::Function::entry_point_offset() - kHeapObjectTag));
__ b(&done);
__ BindUncheckedEntryPoint();
__ mov(
R3,
Operand(target::Function::entry_point_offset(CodeEntryKind::kUnchecked) -
kHeapObjectTag));
__ Bind(&done);
}
// Generate inline cache check for 'num_args'.
// R0: receiver (if instance call)
// R9: ICData
// LR: return address
// Control flow:
// - If receiver is null -> jump to IC miss.
// - If receiver is Smi -> load Smi class.
// - If receiver is not-Smi -> load receiver's class.
// - Check if 'num_args' (including receiver) match any IC data group.
// - Match found -> jump to target.
// - Match not found -> jump to IC miss.
void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
Assembler* assembler,
intptr_t num_args,
const RuntimeEntry& handle_ic_miss,
Token::Kind kind,
Optimized optimized,
CallType type,
Exactness exactness) {
if (FLAG_precompiled_mode) {
__ Breakpoint();
return;
}
const bool save_entry_point = kind == Token::kILLEGAL;
if (save_entry_point) {
GenerateRecordEntryPoint(assembler);
}
if (optimized == kOptimized) {
GenerateOptimizedUsageCounterIncrement(assembler);
} else {
GenerateUsageCounterIncrement(assembler, /* scratch */ R8);
}
ASSERT(exactness == kIgnoreExactness); // Unimplemented.
__ CheckCodePointer();
ASSERT(num_args == 1 || num_args == 2);
#if defined(DEBUG)
{
Label ok;
// Check that the IC data array has NumArgsTested() == num_args.
// 'NumArgsTested' is stored in the least significant bits of 'state_bits'.
__ ldr(R8, FieldAddress(R9, target::ICData::state_bits_offset()));
ASSERT(target::ICData::NumArgsTestedShift() == 0); // No shift needed.
__ and_(R8, R8, Operand(target::ICData::NumArgsTestedMask()));
__ CompareImmediate(R8, num_args);
__ b(&ok, EQ);
__ Stop("Incorrect stub for IC data");
__ Bind(&ok);
}
#endif // DEBUG
#if !defined(PRODUCT)
Label stepping, done_stepping;
if (optimized == kUnoptimized) {
__ Comment("Check single stepping");
__ LoadIsolate(R8);
__ ldrb(R8, Address(R8, target::Isolate::single_step_offset()));
__ CompareImmediate(R8, 0);
__ b(&stepping, NE);
__ Bind(&done_stepping);
}
#endif
Label not_smi_or_overflow;
if (kind != Token::kILLEGAL) {
EmitFastSmiOp(assembler, kind, num_args, &not_smi_or_overflow);
}
__ Bind(&not_smi_or_overflow);
__ Comment("Extract ICData initial values and receiver cid");
// R9: IC data object (preserved).
__ ldr(R8, FieldAddress(R9, target::ICData::entries_offset()));
// R8: ic_data_array with check entries: classes and target functions.
const int kIcDataOffset = target::Array::data_offset() - kHeapObjectTag;
// R8: points at the IC data array.
if (type == kInstanceCall) {
__ LoadTaggedClassIdMayBeSmi(R0, R0);
__ ldr(R4, FieldAddress(
R9, target::CallSiteData::arguments_descriptor_offset()));
if (num_args == 2) {
__ ldr(R1, FieldAddress(R4, target::ArgumentsDescriptor::count_offset()));
__ sub(R1, R1, Operand(target::ToRawSmi(2)));
__ ldr(R1, Address(SP, R1, LSL, 1)); // R1 (argument_count - 2) is Smi.
__ LoadTaggedClassIdMayBeSmi(R1, R1);
}
} else {
// Load arguments descriptor into R4.
__ ldr(R4, FieldAddress(
R9, target::CallSiteData::arguments_descriptor_offset()));
// Get the receiver's class ID (first read number of arguments from
// arguments descriptor array and then access the receiver from the stack).
__ ldr(R1, FieldAddress(R4, target::ArgumentsDescriptor::count_offset()));
__ sub(R1, R1, Operand(target::ToRawSmi(1)));
// R1: argument_count - 1 (smi).
__ ldr(R0, Address(SP, R1, LSL, 1)); // R1 (argument_count - 1) is Smi.
__ LoadTaggedClassIdMayBeSmi(R0, R0);
if (num_args == 2) {
__ sub(R1, R1, Operand(target::ToRawSmi(1)));
__ ldr(R1, Address(SP, R1, LSL, 1)); // R1 (argument_count - 2) is Smi.
__ LoadTaggedClassIdMayBeSmi(R1, R1);
}
}
// R0: first argument class ID as Smi.
// R1: second argument class ID as Smi.
// R4: args descriptor
// Loop that checks if there is an IC data match.
Label loop, found, miss;
__ Comment("ICData loop");
// We unroll the generic one that is generated once more than the others.
const bool optimize = kind == Token::kILLEGAL;
__ Bind(&loop);
for (int unroll = optimize ? 4 : 2; unroll >= 0; unroll--) {
Label update;
__ ldr(R2, Address(R8, kIcDataOffset));
__ cmp(R0, Operand(R2)); // Class id match?
if (num_args == 2) {
__ b(&update, NE); // Continue.
__ ldr(R2, Address(R8, kIcDataOffset + target::kWordSize));
__ cmp(R1, Operand(R2)); // Class id match?
}
__ b(&found, EQ); // Break.
__ Bind(&update);
const intptr_t entry_size = target::ICData::TestEntryLengthFor(
num_args, exactness == kCheckExactness) *
target::kWordSize;
__ AddImmediate(R8, entry_size); // Next entry.
__ CompareImmediate(R2, target::ToRawSmi(kIllegalCid)); // Done?
if (unroll == 0) {
__ b(&loop, NE);
} else {
__ b(&miss, EQ);
}
}
__ Bind(&miss);
__ Comment("IC miss");
// Compute address of arguments.
__ ldr(R1, FieldAddress(R4, target::ArgumentsDescriptor::count_offset()));
__ sub(R1, R1, Operand(target::ToRawSmi(1)));
// R1: argument_count - 1 (smi).
__ add(R1, SP, Operand(R1, LSL, 1)); // R1 is Smi.
// R1: address of receiver.
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
__ LoadImmediate(R0, 0);
// Preserve IC data object and arguments descriptor array and
// setup space on stack for result (target code object).
RegList regs = (1 << R0) | (1 << R4) | (1 << R9);
if (save_entry_point) {
__ SmiTag(R3);
regs |= 1 << R3;
}
__ PushList(regs);
// Push call arguments.
for (intptr_t i = 0; i < num_args; i++) {
__ LoadFromOffset(TMP, R1, -i * target::kWordSize);
__ Push(TMP);
}
// Pass IC data object.
__ Push(R9);
__ CallRuntime(handle_ic_miss, num_args + 1);
// Remove the call arguments pushed earlier, including the IC data object.
__ Drop(num_args + 1);
// Pop returned function object into R0.
// Restore arguments descriptor array and IC data array.
__ PopList(regs);
if (save_entry_point) {
__ SmiUntag(R3);
}
__ RestoreCodePointer();
__ LeaveStubFrame();
Label call_target_function;
if (!FLAG_lazy_dispatchers) {
GenerateDispatcherCode(assembler, &call_target_function);
} else {
__ b(&call_target_function);
}
__ Bind(&found);
// R8: pointer to an IC data check group.
const intptr_t target_offset =
target::ICData::TargetIndexFor(num_args) * target::kWordSize;
const intptr_t count_offset =
target::ICData::CountIndexFor(num_args) * target::kWordSize;
__ LoadFromOffset(R0, R8, kIcDataOffset + target_offset);
if (FLAG_optimization_counter_threshold >= 0) {
__ Comment("Update caller's counter");
__ LoadFromOffset(R1, R8, kIcDataOffset + count_offset);
// Ignore overflow.
__ adds(R1, R1, Operand(target::ToRawSmi(1)));
__ StoreIntoSmiField(Address(R8, kIcDataOffset + count_offset), R1);
}
__ Comment("Call target");
__ Bind(&call_target_function);
// R0: target function.
__ ldr(CODE_REG, FieldAddress(R0, target::Function::code_offset()));
if (save_entry_point) {
__ Branch(Address(R0, R3));
} else {
__ Branch(FieldAddress(R0, target::Function::entry_point_offset()));
}
#if !defined(PRODUCT)
if (optimized == kUnoptimized) {
__ Bind(&stepping);
__ EnterStubFrame();
if (type == kInstanceCall) {
__ Push(R0); // Preserve receiver.
}
RegList regs = 1 << R9;
if (save_entry_point) {
regs |= 1 << R3;
__ SmiTag(R3); // Entry-point is not Smi.
}
__ PushList(regs); // Preserve IC data and entry-point.
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ PopList(regs); // Restore IC data and entry-point
if (save_entry_point) {
__ SmiUntag(R3);
}
if (type == kInstanceCall) {
__ Pop(R0);
}
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
}
#endif
}
// R0: receiver
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateOneArgCheckInlineCacheStub(
Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateOneArgCheckInlineCacheWithExactnessCheckStub(
Assembler* assembler) {
__ Stop("Unimplemented");
}
// R0: receiver
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateTwoArgsCheckInlineCacheStub(
Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateSmiAddInlineCacheStub(Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kADD,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateSmiLessInlineCacheStub(Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kLT,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateSmiEqualInlineCacheStub(Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kEQ,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R9: ICData
// R8: Function
// LR: return address
void StubCodeCompiler::GenerateOneArgOptimizedCheckInlineCacheStub(
Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL,
kOptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R9: ICData
// R8: Function
// LR: return address
void StubCodeCompiler::
GenerateOneArgOptimizedCheckInlineCacheWithExactnessCheckStub(
Assembler* assembler) {
__ Stop("Unimplemented");
}
// R0: receiver
// R9: ICData
// R8: Function
// LR: return address
void StubCodeCompiler::GenerateTwoArgsOptimizedCheckInlineCacheStub(
Assembler* assembler) {
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
kOptimized, kInstanceCall, kIgnoreExactness);
}
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateZeroArgsUnoptimizedStaticCallStub(
Assembler* assembler) {
GenerateRecordEntryPoint(assembler);
GenerateUsageCounterIncrement(assembler, /* scratch */ R8);
#if defined(DEBUG)
{
Label ok;
// Check that the IC data array has NumArgsTested() == 0.
// 'NumArgsTested' is stored in the least significant bits of 'state_bits'.
__ ldr(R8, FieldAddress(R9, target::ICData::state_bits_offset()));
ASSERT(target::ICData::NumArgsTestedShift() == 0); // No shift needed.
__ and_(R8, R8, Operand(target::ICData::NumArgsTestedMask()));
__ CompareImmediate(R8, 0);
__ b(&ok, EQ);
__ Stop("Incorrect IC data for unoptimized static call");
__ Bind(&ok);
}
#endif // DEBUG
#if !defined(PRODUCT)
// Check single stepping.
Label stepping, done_stepping;
__ LoadIsolate(R8);
__ ldrb(R8, Address(R8, target::Isolate::single_step_offset()));
__ CompareImmediate(R8, 0);
__ b(&stepping, NE);
__ Bind(&done_stepping);
#endif
// R9: IC data object (preserved).
__ ldr(R8, FieldAddress(R9, target::ICData::entries_offset()));
// R8: ic_data_array with entries: target functions and count.
__ AddImmediate(R8, target::Array::data_offset() - kHeapObjectTag);
// R8: points directly to the first ic data array element.
const intptr_t target_offset =
target::ICData::TargetIndexFor(0) * target::kWordSize;
const intptr_t count_offset =
target::ICData::CountIndexFor(0) * target::kWordSize;
if (FLAG_optimization_counter_threshold >= 0) {
// Increment count for this call, ignore overflow.
__ LoadFromOffset(R1, R8, count_offset);
__ adds(R1, R1, Operand(target::ToRawSmi(1)));
__ StoreIntoSmiField(Address(R8, count_offset), R1);
}
// Load arguments descriptor into R4.
__ ldr(R4,
FieldAddress(R9, target::CallSiteData::arguments_descriptor_offset()));
// Get function and call it, if possible.
__ LoadFromOffset(R0, R8, target_offset);
__ ldr(CODE_REG, FieldAddress(R0, target::Function::code_offset()));
__ Branch(Address(R0, R3));
#if !defined(PRODUCT)
__ Bind(&stepping);
__ EnterStubFrame();
__ SmiTag(R3); // Entry-point is not Smi.
__ PushList((1 << R9) | (1 << R3)); // Preserve IC data and entry-point.
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ PopList((1 << R9) | (1 << R3));
__ SmiUntag(R3);
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
#endif
}
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateOneArgUnoptimizedStaticCallStub(
Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, /* scratch */ R8);
GenerateNArgsCheckInlineCacheStub(
assembler, 1, kStaticCallMissHandlerOneArgRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kStaticCall, kIgnoreExactness);
}
// R9: ICData
// LR: return address
void StubCodeCompiler::GenerateTwoArgsUnoptimizedStaticCallStub(
Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, /* scratch */ R8);
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kStaticCallMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kStaticCall, kIgnoreExactness);
}
// Stub for compiling a function and jumping to the compiled code.
// R4: Arguments descriptor.
// R0: Function.
void StubCodeCompiler::GenerateLazyCompileStub(Assembler* assembler) {
__ EnterStubFrame();
__ PushList((1 << R0) | (1 << R4)); // Preserve arg desc, pass function.
__ CallRuntime(kCompileFunctionRuntimeEntry, 1);
__ PopList((1 << R0) | (1 << R4));
__ LeaveStubFrame();
__ ldr(CODE_REG, FieldAddress(R0, target::Function::code_offset()));
__ Branch(FieldAddress(R0, target::Function::entry_point_offset()));
}
// R9: Contains an ICData.
void StubCodeCompiler::GenerateICCallBreakpointStub(Assembler* assembler) {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(R9); // Preserve IC data.
__ PushImmediate(0); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG); // Original stub.
__ Pop(R9); // Restore IC data.
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ Branch(FieldAddress(CODE_REG, target::Code::entry_point_offset()));
#endif // defined(PRODUCT)
}
void StubCodeCompiler::GenerateUnoptStaticCallBreakpointStub(
Assembler* assembler) {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
__ EnterStubFrame();
__ Push(R9); // Preserve IC data.
__ PushImmediate(0); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG); // Original stub.
__ Pop(R9); // Restore IC data.
__ LeaveStubFrame();
__ Branch(FieldAddress(CODE_REG, target::Code::entry_point_offset()));
#endif // defined(PRODUCT)
}
void StubCodeCompiler::GenerateRuntimeCallBreakpointStub(Assembler* assembler) {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
__ EnterStubFrame();
__ LoadImmediate(R0, 0);
// Make room for result.
__ PushList((1 << R0));
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ PopList((1 << CODE_REG));
__ LeaveStubFrame();
__ Branch(FieldAddress(CODE_REG, target::Code::entry_point_offset()));
#endif // defined(PRODUCT)
}
// Called only from unoptimized code. All relevant registers have been saved.
void StubCodeCompiler::GenerateDebugStepCheckStub(Assembler* assembler) {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
// Check single stepping.
Label stepping, done_stepping;
__ LoadIsolate(R1);
__ ldrb(R1, Address(R1, target::Isolate::single_step_offset()));
__ CompareImmediate(R1, 0);
__ b(&stepping, NE);
__ Bind(&done_stepping);
__ Ret();
__ Bind(&stepping);
__ EnterStubFrame();
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ LeaveStubFrame();
__ b(&done_stepping);
#endif // defined(PRODUCT)
}
// Used to check class and type arguments. Arguments passed in registers:
//
// Inputs (mostly from TypeTestABI struct):
// - kSubtypeTestCacheReg: SubtypeTestCacheLayout
// - kInstanceReg: instance to test against.
// - kDstTypeReg: destination type (for n>=3).
// - kInstantiatorTypeArgumentsReg: instantiator type arguments (for n=5).
// - kFunctionTypeArgumentsReg: function type arguments (for n=5).
// - LR: return address.
//
// All TypeTestABI registers are preserved but kSubtypeTestCacheReg, which must
// be saved by the caller if the original value is needed after the call.
//
// Result in SubtypeTestCacheABI::kResultReg: null -> not found, otherwise
// result (true or false).
static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
ASSERT(n == 1 || n == 3 || n == 5 || n == 7);
// Safe as the original value of TypeTestABI::kSubtypeTestCacheReg is only
// used to initialize this register.
const Register kCacheArrayReg = TypeTestABI::kSubtypeTestCacheReg;
const Register kScratchReg = TypeTestABI::kScratchReg;
// Registers that are only used for n >= 3 and must be preserved if used.
Register kInstanceInstantiatorTypeArgumentsReg = kNoRegister;
// Registers that are only used for n >= 7 and must be preserved if used.
Register kInstanceParentFunctionTypeArgumentsReg = kNoRegister;
// There is no register for InstanceDelayedFunctionTypeArguments, it is
// instead placed on the stack and pulled into TMP for comparison against
// the corresponding slot in the current cache entry.
// NOTFP must be preserved for bare payloads, otherwise CODE_REG.
const bool use_bare_payloads =
FLAG_precompiled_mode && FLAG_use_bare_instructions;
// For this, we choose the register that need not be preserved of the pair.
const Register kNullReg = use_bare_payloads ? CODE_REG : NOTFP;
__ LoadObject(kNullReg, NullObject());
// Free up registers to be used if performing a 3, 5, or 7 value test.
RegList pushed_registers = 0;
if (n >= 3) {
kInstanceInstantiatorTypeArgumentsReg = PP;
pushed_registers |= 1 << kInstanceInstantiatorTypeArgumentsReg;
}
if (n >= 7) {
// For this, we choose the register that must be preserved of the pair.
kInstanceParentFunctionTypeArgumentsReg =
use_bare_payloads ? NOTFP : CODE_REG;
pushed_registers |= 1 << kInstanceParentFunctionTypeArgumentsReg;
}
if (pushed_registers != 0) {
__ PushList(pushed_registers);
}
// Loop initialization (moved up here to avoid having all dependent loads
// after each other).
// We avoid a load-acquire barrier here by relying on the fact that all other
// loads from the array are data-dependent loads.
__ ldr(kCacheArrayReg,
FieldAddress(TypeTestABI::kSubtypeTestCacheReg,
target::SubtypeTestCache::cache_offset()));
__ AddImmediate(kCacheArrayReg,
target::Array::data_offset() - kHeapObjectTag);
Label loop, not_closure;
if (n >= 5) {
__ LoadClassIdMayBeSmi(STCInternalRegs::kInstanceCidOrFunctionReg,
TypeTestABI::kInstanceReg);
} else {
__ LoadClassId(STCInternalRegs::kInstanceCidOrFunctionReg,
TypeTestABI::kInstanceReg);
}
__ CompareImmediate(STCInternalRegs::kInstanceCidOrFunctionReg, kClosureCid);
__ b(&not_closure, NE);
// Closure handling.
{
__ ldr(STCInternalRegs::kInstanceCidOrFunctionReg,
FieldAddress(TypeTestABI::kInstanceReg,
target::Closure::function_offset()));
if (n >= 3) {
__ ldr(
kInstanceInstantiatorTypeArgumentsReg,
FieldAddress(TypeTestABI::kInstanceReg,
target::Closure::instantiator_type_arguments_offset()));
if (n >= 7) {
__ ldr(kInstanceParentFunctionTypeArgumentsReg,
FieldAddress(TypeTestABI::kInstanceReg,
target::Closure::function_type_arguments_offset()));
__ ldr(kScratchReg,
FieldAddress(TypeTestABI::kInstanceReg,
target::Closure::delayed_type_arguments_offset()));
__ PushRegister(kScratchReg);
}
}
__ b(&loop);
}
// Non-Closure handling.
{
__ Bind(&not_closure);
if (n >= 3) {
Label has_no_type_arguments;
__ LoadClassById(kScratchReg, STCInternalRegs::kInstanceCidOrFunctionReg);
__ mov(kInstanceInstantiatorTypeArgumentsReg, Operand(kNullReg));
__ ldr(
kScratchReg,
FieldAddress(kScratchReg,
target::Class::
host_type_arguments_field_offset_in_words_offset()));
__ CompareImmediate(kScratchReg, target::Class::kNoTypeArguments);
__ b(&has_no_type_arguments, EQ);
__ add(kScratchReg, TypeTestABI::kInstanceReg,
Operand(kScratchReg, LSL, 2));
__ ldr(kInstanceInstantiatorTypeArgumentsReg,
FieldAddress(kScratchReg, 0));
__ Bind(&has_no_type_arguments);
if (n >= 7) {
__ mov(kInstanceParentFunctionTypeArgumentsReg, Operand(kNullReg));
__ PushRegister(kNullReg);
}
}
__ SmiTag(STCInternalRegs::kInstanceCidOrFunctionReg);
}
const intptr_t kNoDepth = -1;
const intptr_t kInstanceDelayedFunctionTypeArgumentsDepth =
n >= 7 ? 0 : kNoDepth;
Label found, not_found, next_iteration;
// Loop header.
__ Bind(&loop);
__ ldr(kScratchReg,
Address(kCacheArrayReg,
target::kWordSize *
target::SubtypeTestCache::kInstanceClassIdOrFunction));
__ cmp(kScratchReg, Operand(kNullReg));
__ b(&not_found, EQ);
__ cmp(kScratchReg, Operand(STCInternalRegs::kInstanceCidOrFunctionReg));
if (n == 1) {
__ b(&found, EQ);
} else {
__ b(&next_iteration, NE);
__ ldr(kScratchReg,
Address(
kCacheArrayReg,
target::kWordSize * target::SubtypeTestCache::kDestinationType));
__ cmp(kScratchReg, Operand(TypeTestABI::kDstTypeReg));
__ b(&next_iteration, NE);
__ ldr(kScratchReg,
Address(kCacheArrayReg,
target::kWordSize *
target::SubtypeTestCache::kInstanceTypeArguments));
__ cmp(kScratchReg, Operand(kInstanceInstantiatorTypeArgumentsReg));
if (n == 3) {
__ b(&found, EQ);
} else {
__ b(&next_iteration, NE);
__ ldr(kScratchReg,
Address(kCacheArrayReg,
target::kWordSize *
target::SubtypeTestCache::kInstantiatorTypeArguments));
__ cmp(kScratchReg, Operand(TypeTestABI::kInstantiatorTypeArgumentsReg));
__ b(&next_iteration, NE);
__ ldr(kScratchReg,
Address(kCacheArrayReg,
target::kWordSize *
target::SubtypeTestCache::kFunctionTypeArguments));
__ cmp(kScratchReg, Operand(TypeTestABI::kFunctionTypeArgumentsReg));
if (n == 5) {
__ b(&found, EQ);
} else {
ASSERT(n == 7);
__ b(&next_iteration, NE);
__ ldr(kScratchReg,
Address(kCacheArrayReg,
target::kWordSize *
target::SubtypeTestCache::
kInstanceParentFunctionTypeArguments));
__ cmp(kScratchReg, Operand(kInstanceParentFunctionTypeArgumentsReg));
__ b(&next_iteration, NE);
__ ldr(kScratchReg,
Address(kCacheArrayReg,
target::kWordSize *
target::SubtypeTestCache::
kInstanceDelayedFunctionTypeArguments));
__ CompareToStack(kScratchReg,
kInstanceDelayedFunctionTypeArgumentsDepth);
__ b(&found, EQ);
}
}
}
__ Bind(&next_iteration);
__ AddImmediate(
kCacheArrayReg,
target::kWordSize * target::SubtypeTestCache::kTestEntryLength);
__ b(&loop);
__ Bind(&found);
__ ldr(TypeTestABI::kSubtypeTestCacheResultReg,
Address(kCacheArrayReg,
target::kWordSize * target::SubtypeTestCache::kTestResult));
if (n >= 7) {
__ Drop(1); // delayed function type args.
}
if (pushed_registers != 0) {
__ PopList(pushed_registers);
}
__ Ret();
__ Bind(&not_found);
__ mov(TypeTestABI::kSubtypeTestCacheResultReg, Operand(kNullReg));
if (n >= 7) {
__ Drop(1); // delayed function type args.
}
if (pushed_registers != 0) {
__ PopList(pushed_registers);
}
__ Ret();
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCodeCompiler::GenerateSubtype1TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 1);
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCodeCompiler::GenerateSubtype3TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 3);
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCodeCompiler::GenerateSubtype5TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 5);
}
// See comment on[GenerateSubtypeNTestCacheStub].
void StubCodeCompiler::GenerateSubtype7TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 7);
}
// Return the current stack pointer address, used to do stack alignment checks.
void StubCodeCompiler::GenerateGetCStackPointerStub(Assembler* assembler) {
__ mov(R0, Operand(SP));
__ Ret();
}
// Jump to a frame on the call stack.
// LR: return address.
// R0: program_counter.
// R1: stack_pointer.
// R2: frame_pointer.
// R3: thread.
// Does not return.
//
// Notice: We need to keep this in sync with `Simulator::JumpToFrame()`.
void StubCodeCompiler::GenerateJumpToFrameStub(Assembler* assembler) {
COMPILE_ASSERT(kExceptionObjectReg == R0);
COMPILE_ASSERT(kStackTraceObjectReg == R1);
COMPILE_ASSERT(IsAbiPreservedRegister(R4));
COMPILE_ASSERT(IsAbiPreservedRegister(THR));
__ mov(IP, Operand(R1)); // Copy Stack pointer into IP.
// TransitionGeneratedToNative might clobber LR if it takes the slow path.
__ mov(R4, Operand(R0)); // Program counter.
__ mov(THR, Operand(R3)); // Thread.
__ mov(FP, Operand(R2)); // Frame_pointer.
__ mov(SP, Operand(IP)); // Set Stack pointer.
#if defined(USING_SHADOW_CALL_STACK)
#error Unimplemented
#endif
Label exit_through_non_ffi;
Register tmp1 = R0, tmp2 = R1;
// Check if we exited generated from FFI. If so do transition.
__ LoadFromOffset(tmp1, THR,
compiler::target::Thread::exit_through_ffi_offset());
__ LoadImmediate(tmp2, target::Thread::exit_through_ffi());
__ cmp(tmp1, Operand(tmp2));
__ b(&exit_through_non_ffi, NE);
__ TransitionNativeToGenerated(tmp1, tmp2,
/*leave_safepoint=*/true);
__ Bind(&exit_through_non_ffi);
// Set the tag.
__ LoadImmediate(R2, VMTag::kDartTagId);
__ StoreToOffset(R2, THR, target::Thread::vm_tag_offset());
// Clear top exit frame.
__ LoadImmediate(R2, 0);
__ StoreToOffset(R2, THR, target::Thread::top_exit_frame_info_offset());
// Restore the pool pointer.
__ RestoreCodePointer();
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ SetupGlobalPoolAndDispatchTable();
__ set_constant_pool_allowed(true);
} else {
__ LoadPoolPointer();
}
__ bx(R4); // Jump to continuation point.
}
// Run an exception handler. Execution comes from JumpToFrame
// stub or from the simulator.
//
// The arguments are stored in the Thread object.
// Does not return.
void StubCodeCompiler::GenerateRunExceptionHandlerStub(Assembler* assembler) {
WRITES_RETURN_ADDRESS_TO_LR(
__ LoadFromOffset(LR, THR, target::Thread::resume_pc_offset()));
word offset_from_thread = 0;
bool ok = target::CanLoadFromThread(NullObject(), &offset_from_thread);
ASSERT(ok);
__ LoadFromOffset(R2, THR, offset_from_thread);
// Exception object.
__ LoadFromOffset(R0, THR, target::Thread::active_exception_offset());
__ StoreToOffset(R2, THR, target::Thread::active_exception_offset());
// StackTrace object.
__ LoadFromOffset(R1, THR, target::Thread::active_stacktrace_offset());
__ StoreToOffset(R2, THR, target::Thread::active_stacktrace_offset());
READS_RETURN_ADDRESS_FROM_LR(
__ bx(LR)); // Jump to the exception handler code.
}
// Deoptimize a frame on the call stack before rewinding.
// The arguments are stored in the Thread object.
// No result.
void StubCodeCompiler::GenerateDeoptForRewindStub(Assembler* assembler) {
// Push zap value instead of CODE_REG.
__ LoadImmediate(IP, kZapCodeReg);
__ Push(IP);
// Load the deopt pc into LR.
WRITES_RETURN_ADDRESS_TO_LR(
__ LoadFromOffset(LR, THR, target::Thread::resume_pc_offset()));
GenerateDeoptimizationSequence(assembler, kEagerDeopt);
// After we have deoptimized, jump to the correct frame.
__ EnterStubFrame();
__ CallRuntime(kRewindPostDeoptRuntimeEntry, 0);
__ LeaveStubFrame();
__ bkpt(0);
}
// Calls to the runtime to optimize the given function.
// R8: function to be reoptimized.
// R4: argument descriptor (preserved).
void StubCodeCompiler::GenerateOptimizeFunctionStub(Assembler* assembler) {
__ ldr(CODE_REG, Address(THR, target::Thread::optimize_stub_offset()));
__ EnterStubFrame();
__ Push(R4);
__ LoadImmediate(IP, 0);
__ Push(IP); // Setup space on stack for return value.
__ Push(R8);
__ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry, 1);
__ Pop(R0); // Discard argument.
__ Pop(R0); // Get Function object
__ Pop(R4); // Restore argument descriptor.
__ LeaveStubFrame();
__ ldr(CODE_REG, FieldAddress(R0, target::Function::code_offset()));
__ Branch(FieldAddress(R0, target::Function::entry_point_offset()));
__ bkpt(0);
}
// Does identical check (object references are equal or not equal) with special
// checks for boxed numbers.