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dart / sdk / 323a15b6e4423de90dc5ab0a87c5b51b0f4ea53a / . / runtime / vm / compiler / stub_code_compiler_arm64.cc
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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/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_ARM64)
#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/ffi_callback_metadata.h"
#include "vm/instructions.h"
#include "vm/static_type_exactness_state.h"
#include "vm/tags.h"
#define __ assembler->
namespace dart {
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.
void StubCodeCompiler::EnsureIsNewOrRemembered() {
// If the object is not in an active TLAB, we call a leaf-runtime to add it to
// the remembered set and/or deferred marking worklist. This test assumes a
// Page's TLAB use is always ascending.
Label done;
__ AndImmediate(TMP, R0, target::kPageMask);
__ LoadFromOffset(TMP, Address(TMP, target::Page::original_top_offset()));
__ CompareRegisters(R0, TMP);
__ BranchIf(UNSIGNED_GREATER_EQUAL, &done);
{
LeafRuntimeScope rt(assembler, /*frame_size=*/0,
/*preserve_registers=*/false);
// R0 already loaded.
__ mov(R1, THR);
rt.Call(kEnsureRememberedAndMarkingDeferredRuntimeEntry,
/*argument_count=*/2);
}
__ Bind(&done);
}
// In TSAN mode the runtime will throw an exception using an intermediary
// longjmp() call to unwind the C frames in a way that TSAN can understand.
//
// This wrapper will setup a [jmp_buf] on the stack and initialize it to be a
// target for a possible longjmp(). In the exceptional case we'll forward
// control of execution to the usual JumpToFrame stub.
//
// In non-TSAN mode this will do nothing and the runtime will call the
// JumpToFrame stub directly.
//
// The callback [fun] may be invoked with a modified [RSP] due to allocating
// a [jmp_buf] allocating structure on the stack (as well as the saved old
// [Thread::tsan_utils_->setjmp_buffer_]).
static void WithExceptionCatchingTrampoline(Assembler* assembler,
std::function<void()> fun) {
#if defined(TARGET_USES_THREAD_SANITIZER) && !defined(USING_SIMULATOR)
const Register kTsanUtilsReg = R3;
// Reserve space for arguments and align frame before entering C++ world.
const intptr_t kJumpBufferSize = sizeof(jmp_buf);
// Save & Restore the volatile CPU registers across the setjmp() call.
const RegisterSet volatile_registers(
kAbiVolatileCpuRegs & ~(1 << R0) & ~(1 << SP),
/*fpu_registers=*/0);
const Register kSavedRspReg = R20;
COMPILE_ASSERT(IsCalleeSavedRegister(kSavedRspReg));
// We rely on THR being preserved across the setjmp() call.
COMPILE_ASSERT(IsCalleeSavedRegister(THR));
Label do_native_call;
// Save old jmp_buf.
__ ldr(kTsanUtilsReg, Address(THR, target::Thread::tsan_utils_offset()));
__ ldr(TMP,
Address(kTsanUtilsReg, target::TsanUtils::setjmp_buffer_offset()));
__ Push(TMP);
// Allocate jmp_buf struct on stack & remember pointer to it on the
// [Thread::tsan_utils_->setjmp_buffer] (which exceptions.cc will longjmp()
// to)
__ AddImmediate(SP, -kJumpBufferSize);
__ str(SP, Address(kTsanUtilsReg, target::TsanUtils::setjmp_buffer_offset()));
// Call setjmp() with a pointer to the allocated jmp_buf struct.
__ MoveRegister(R0, SP);
__ PushRegisters(volatile_registers);
__ EnterCFrame(0);
__ mov(R25, CSP);
__ mov(CSP, SP);
__ ldr(kTsanUtilsReg, Address(THR, target::Thread::tsan_utils_offset()));
__ CallCFunction(
Address(kTsanUtilsReg, target::TsanUtils::setjmp_function_offset()));
__ mov(SP, CSP);
__ mov(CSP, R25);
__ LeaveCFrame();
__ PopRegisters(volatile_registers);
// We are the target of a longjmp() iff setjmp() returns non-0.
__ cbz(&do_native_call, R0);
// We are the target of a longjmp: Cleanup the stack and tail-call the
// JumpToFrame stub which will take care of unwinding the stack and hand
// execution to the catch entry.
__ AddImmediate(SP, kJumpBufferSize);
__ ldr(kTsanUtilsReg, Address(THR, target::Thread::tsan_utils_offset()));
__ Pop(TMP);
__ str(TMP,
Address(kTsanUtilsReg, target::TsanUtils::setjmp_buffer_offset()));
__ ldr(R0, Address(kTsanUtilsReg, target::TsanUtils::exception_pc_offset()));
__ ldr(R1, Address(kTsanUtilsReg, target::TsanUtils::exception_sp_offset()));
__ ldr(R2, Address(kTsanUtilsReg, target::TsanUtils::exception_fp_offset()));
__ MoveRegister(R3, THR);
__ Jump(Address(THR, target::Thread::jump_to_frame_entry_point_offset()));
// We leave the created [jump_buf] structure on the stack as well as the
// pushed old [Thread::tsan_utils_->setjmp_buffer_].
__ Bind(&do_native_call);
__ MoveRegister(kSavedRspReg, SP);
#endif // defined(TARGET_USES_THREAD_SANITIZER) && !defined(USING_SIMULATOR)
fun();
#if defined(TARGET_USES_THREAD_SANITIZER) && !defined(USING_SIMULATOR)
__ MoveRegister(SP, kSavedRspReg);
__ AddImmediate(SP, kJumpBufferSize);
const Register kTsanUtilsReg2 = kSavedRspReg;
__ ldr(kTsanUtilsReg2, Address(THR, target::Thread::tsan_utils_offset()));
__ Pop(TMP);
__ str(TMP,
Address(kTsanUtilsReg2, target::TsanUtils::setjmp_buffer_offset()));
#endif // defined(TARGET_USES_THREAD_SANITIZER) && !defined(USING_SIMULATOR)
}
// Input parameters:
// LR : return address.
// SP : address of last argument in argument array.
// SP + 8*R4 - 8 : address of first argument in argument array.
// SP + 8*R4 : address of return value.
// R5 : address of the runtime function to call.
// R4 : number of arguments to the call.
void StubCodeCompiler::GenerateCallToRuntimeStub() {
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();
__ Comment("CallToRuntimeStub");
__ ldr(CODE_REG, Address(THR, target::Thread::call_to_runtime_stub_offset()));
__ SetPrologueOffset();
__ 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(R5, THR, target::Thread::vm_tag_offset());
WithExceptionCatchingTrampoline(assembler, [&]() {
// Reserve space for arguments and align frame before entering C++ world.
// target::NativeArguments are passed in registers.
__ Comment("align stack");
// Reserve space for arguments.
ASSERT(target::NativeArguments::StructSize() == 4 * target::kWordSize);
__ ReserveAlignedFrameSpace(target::NativeArguments::StructSize());
// 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, THR);
ASSERT(argc_tag_offset == 1 * target::kWordSize);
__ mov(R1, R4); // Set argc in target::NativeArguments.
ASSERT(argv_offset == 2 * target::kWordSize);
__ add(R2, ZR, Operand(R4, LSL, 3));
__ add(R2, FP, Operand(R2)); // Compute argv.
// Set argv in target::NativeArguments.
__ AddImmediate(R2,
target::frame_layout.param_end_from_fp * target::kWordSize);
ASSERT(retval_offset == 3 * target::kWordSize);
__ AddImmediate(R3, R2, target::kWordSize);
__ StoreToOffset(R0, SP, thread_offset);
__ StoreToOffset(R1, SP, argc_tag_offset);
__ StoreToOffset(R2, SP, argv_offset);
__ StoreToOffset(R3, SP, retval_offset);
__ mov(R0, SP); // Pass the pointer to the target::NativeArguments.
// We are entering runtime code, so the C stack pointer must be restored
// from the stack limit to the top of the stack. We cache the stack limit
// address in a callee-saved register.
__ mov(R25, CSP);
__ mov(CSP, SP);
__ blr(R5);
__ Comment("CallToRuntimeStub return");
// Restore SP and CSP.
__ mov(SP, CSP);
__ mov(CSP, R25);
// Refresh pinned registers (write barrier mask, null, dispatch table, etc).
__ RestorePinnedRegisters();
// Retval is next to 1st argument.
// 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.
__ StoreToOffset(ZR, THR, target::Thread::exit_through_ffi_offset());
// Reset exit frame information in Isolate's mutator thread structure.
__ StoreToOffset(ZR, 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) {
__ 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(
bool save_fpu_registers,
intptr_t self_code_stub_offset_from_thread,
bool allow_return,
std::function<void()> perform_runtime_call) {
// 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(__ ret(LR));
}
void StubCodeCompiler::GenerateSharedStub(
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) {
__ PushRegister(NULL_REG);
}
__ 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(save_fpu_registers,
self_code_stub_offset_from_thread, allow_return,
perform_runtime_call);
}
void StubCodeCompiler::GenerateEnterSafepointStub() {
RegisterSet all_registers;
all_registers.AddAllGeneralRegisters();
__ EnterFrame(0);
__ PushRegisters(all_registers);
__ mov(CALLEE_SAVED_TEMP, CSP);
__ mov(CALLEE_SAVED_TEMP2, SP);
__ ReserveAlignedFrameSpace(0);
__ mov(CSP, SP);
__ ldr(R0, Address(THR, kEnterSafepointRuntimeEntry.OffsetFromThread()));
__ blr(R0);
__ mov(SP, CALLEE_SAVED_TEMP2);
__ mov(CSP, CALLEE_SAVED_TEMP);
__ PopRegisters(all_registers);
__ LeaveFrame();
__ Ret();
}
static void GenerateExitSafepointStubCommon(Assembler* assembler,
uword runtime_entry_offset) {
RegisterSet all_registers;
all_registers.AddAllGeneralRegisters();
__ EnterFrame(0);
__ PushRegisters(all_registers);
__ mov(CALLEE_SAVED_TEMP, CSP);
__ mov(CALLEE_SAVED_TEMP2, SP);
__ ReserveAlignedFrameSpace(0);
__ mov(CSP, SP);
// 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, runtime_entry_offset));
__ blr(R0);
__ mov(SP, CALLEE_SAVED_TEMP2);
__ mov(CSP, CALLEE_SAVED_TEMP);
__ PopRegisters(all_registers);
__ LeaveFrame();
__ Ret();
}
void StubCodeCompiler::GenerateExitSafepointStub() {
GenerateExitSafepointStubCommon(
assembler, kExitSafepointRuntimeEntry.OffsetFromThread());
}
void StubCodeCompiler::GenerateExitSafepointIgnoreUnwindInProgressStub() {
GenerateExitSafepointStubCommon(
assembler,
kExitSafepointIgnoreUnwindInProgressRuntimeEntry.OffsetFromThread());
}
// Calls native code within a safepoint.
//
// On entry:
// R9: target to call
// Stack: set up for native call (SP), aligned, CSP < SP
//
// On exit:
// R19: clobbered, although normally callee-saved
// Stack: preserved, CSP == SP
void StubCodeCompiler::GenerateCallNativeThroughSafepointStub() {
COMPILE_ASSERT(IsAbiPreservedRegister(R19));
SPILLS_RETURN_ADDRESS_FROM_LR_TO_REGISTER(__ mov(R19, LR));
__ LoadImmediate(R10, target::Thread::exit_through_ffi());
__ TransitionGeneratedToNative(R9, FPREG, R10 /*volatile*/,
/*enter_safepoint=*/true);
__ mov(R25, CSP);
__ mov(CSP, SP);
#if defined(DEBUG)
// Check CSP alignment.
__ andi(R11 /*volatile*/, SP,
Immediate(~(OS::ActivationFrameAlignment() - 1)));
__ cmp(R11, Operand(SP));
Label done;
__ b(&done, EQ);
__ Breakpoint();
__ Bind(&done);
#endif
__ blr(R9);
__ mov(SP, CSP);
__ mov(CSP, R25);
__ TransitionNativeToGenerated(R10, /*leave_safepoint=*/true);
__ ret(R19);
}
void StubCodeCompiler::GenerateLoadBSSEntry(BSS::Relocation relocation,
Register dst,
Register tmp) {
compiler::Label skip_reloc;
__ b(&skip_reloc);
InsertBSSRelocation(relocation);
__ Bind(&skip_reloc);
__ adr(tmp, compiler::Immediate(-compiler::target::kWordSize));
// tmp holds the address of the relocation.
__ ldr(dst, compiler::Address(tmp));
// dst holds the relocation itself: tmp - bss_start.
// tmp = tmp + (bss_start - tmp) = bss_start
__ add(tmp, tmp, compiler::Operand(dst));
// tmp holds the start of the BSS section.
// Load the "get-thread" routine: *bss_start.
__ ldr(dst, compiler::Address(tmp));
}
void StubCodeCompiler::GenerateLoadFfiCallbackMetadataRuntimeFunction(
uword function_index,
Register dst) {
// Keep in sync with FfiCallbackMetadata::EnsureFirstTrampolinePageLocked.
// Note: If the stub was aligned, this could be a single PC relative load.
// Load a pointer to the beginning of the stub into dst.
const intptr_t code_size = __ CodeSize();
__ adr(dst, Immediate(-code_size));
// Round dst down to the page size.
__ andi(dst, dst, Immediate(FfiCallbackMetadata::kPageMask));
// Load the function from the function table.
__ LoadFromOffset(
dst,
Address(dst, FfiCallbackMetadata::RuntimeFunctionOffset(function_index)));
}
void StubCodeCompiler::GenerateFfiCallbackTrampolineStub() {
#if defined(USING_SIMULATOR) && !defined(DART_PRECOMPILER)
// TODO(37299): FFI is not supported in SIMARM64.
__ Breakpoint();
#else
Label body;
// R9 is volatile and not used for passing any arguments.
COMPILE_ASSERT(!IsCalleeSavedRegister(R9) && !IsArgumentRegister(R9));
for (intptr_t i = 0; i < FfiCallbackMetadata::NumCallbackTrampolinesPerPage();
++i) {
// The FfiCallbackMetadata table is keyed by the trampoline entry point. So
// look up the current PC, then jump to the shared section.
__ adr(R9, Immediate(0));
__ b(&body);
}
ASSERT_EQUAL(__ CodeSize(),
FfiCallbackMetadata::kNativeCallbackTrampolineSize *
FfiCallbackMetadata::NumCallbackTrampolinesPerPage());
__ Bind(&body);
const intptr_t shared_stub_start = __ CodeSize();
// Save THR (callee-saved) and LR on the real C stack (CSP). Keeps it
// aligned.
COMPILE_ASSERT(FfiCallbackMetadata::kNativeCallbackTrampolineStackDelta == 2);
SPILLS_LR_TO_FRAME(__ stp(
THR, LR, Address(CSP, -2 * target::kWordSize, Address::PairPreIndex)));
COMPILE_ASSERT(!IsArgumentRegister(THR));
RegisterSet all_registers;
all_registers.AddAllArgumentRegisters();
all_registers.Add(Location::RegisterLocation(
CallingConventions::kPointerToReturnStructRegisterCall));
// Load the thread, verify the callback ID and exit the safepoint.
//
// We exit the safepoint inside DLRT_GetFfiCallbackMetadata in order to save
// code size on this shared stub.
{
__ SetupDartSP();
__ EnterFrame(0);
__ PushRegisters(all_registers);
__ mov(R0, R9);
// We also need to look up the entry point for the trampoline. This is
// returned using a pointer passed to the second arg of the C function
// below. We aim that pointer at a reserved stack slot.
__ AddImmediate(SP, SP, -compiler::target::kWordSize);
__ mov(R1, SP);
// We also need to know if this is a sync or async callback. This is also
// returned by pointer.
__ AddImmediate(SP, SP, -compiler::target::kWordSize);
__ mov(R2, SP);
__ EnterFrame(0);
__ ReserveAlignedFrameSpace(0);
#if defined(DART_TARGET_OS_FUCHSIA)
// TODO(https://dartbug.com/52579): Remove.
if (FLAG_precompiled_mode) {
GenerateLoadBSSEntry(BSS::Relocation::DRT_GetFfiCallbackMetadata, R4, R9);
} else {
Label call;
__ ldr(R4, compiler::Address::PC(2 * Instr::kInstrSize));
__ b(&call);
__ Emit64(reinterpret_cast<int64_t>(&DLRT_GetFfiCallbackMetadata));
__ Bind(&call);
}
#else
GenerateLoadFfiCallbackMetadataRuntimeFunction(
FfiCallbackMetadata::kGetFfiCallbackMetadata, R4);
#endif // defined(DART_TARGET_OS_FUCHSIA)
__ mov(CSP, SP);
__ blr(R4);
__ mov(SP, CSP);
__ mov(THR, R0);
__ LeaveFrame();
// The trampoline type is at the top of the stack. Pop it into R9.
__ Pop(R9);
// Entry point is now at the top of the stack. Pop it into R10.
COMPILE_ASSERT(!IsCalleeSavedRegister(R10) && !IsArgumentRegister(R10));
__ Pop(R10);
__ PopRegisters(all_registers);
__ LeaveFrame();
__ RestoreCSP();
}
Label async_callback;
Label done;
// If GetFfiCallbackMetadata returned a null thread, it means that the async
// callback was invoked after it was deleted. In this case, do nothing.
__ cmp(THR, Operand(0));
__ b(&done, EQ);
// Check the trampoline type to see how the callback should be invoked.
__ cmp(
R9,
Operand(static_cast<uword>(FfiCallbackMetadata::TrampolineType::kAsync)));
__ b(&async_callback, EQ);
// Sync callback. The entry point contains the target function, so just call
// it. DLRT_GetThreadForNativeCallbackTrampoline exited the safepoint, so
// re-enter it afterwards.
// Clobbers all volatile registers, including the callback ID in R9.
// Resets CSP and SP, important for EnterSafepoint below.
__ blr(R10);
// Clobbers TMP, TMP2 and R9 -- all volatile and not holding return values.
__ EnterFullSafepoint(/*scratch=*/R9);
__ b(&done);
__ Bind(&async_callback);
// Async callback. The entrypoint marshals the arguments into a message and
// sends it over the send port. DLRT_GetThreadForNativeCallbackTrampoline
// entered a temporary isolate, so exit it afterwards.
// Clobbers all volatile registers, including the callback ID in R9.
// Resets CSP and SP, important for EnterSafepoint below.
__ blr(R10);
// Exit the temporary isolate.
{
__ SetupDartSP();
__ EnterFrame(0);
__ ReserveAlignedFrameSpace(0);
#if defined(DART_TARGET_OS_FUCHSIA)
// TODO(https://dartbug.com/52579): Remove.
if (FLAG_precompiled_mode) {
GenerateLoadBSSEntry(BSS::Relocation::DRT_ExitTemporaryIsolate, R4, R9);
} else {
Label call;
__ ldr(R4, compiler::Address::PC(2 * Instr::kInstrSize));
__ b(&call);
__ Emit64(reinterpret_cast<int64_t>(&DLRT_ExitTemporaryIsolate));
__ Bind(&call);
}
#else
GenerateLoadFfiCallbackMetadataRuntimeFunction(
FfiCallbackMetadata::kExitTemporaryIsolate, R4);
#endif
__ mov(CSP, SP);
__ blr(R4);
__ mov(SP, CSP);
__ mov(THR, R0);
__ LeaveFrame();
__ RestoreCSP();
}
__ Bind(&done);
// Pop LR and THR from the real stack (CSP).
RESTORES_LR_FROM_FRAME(__ ldp(
THR, LR, Address(CSP, 2 * target::kWordSize, Address::PairPostIndex)));
__ ret();
ASSERT_LESS_OR_EQUAL(__ CodeSize() - shared_stub_start,
FfiCallbackMetadata::kNativeCallbackSharedStubSize);
ASSERT_LESS_OR_EQUAL(__ CodeSize(), FfiCallbackMetadata::kPageSize);
#if defined(DEBUG)
while (__ CodeSize() < FfiCallbackMetadata::kPageSize) {
__ Breakpoint();
}
#endif
#endif // !defined(HOST_ARCH_ARM64)
}
// R1: The extracted method.
// R4: The type_arguments_field_offset (or 0)
void StubCodeCompiler::GenerateBuildMethodExtractorStub(
const Code& closure_allocation_stub,
const Code& context_allocation_stub,
bool generic) {
const intptr_t kReceiverOffset = target::frame_layout.param_end_from_fp + 1;
__ EnterStubFrame();
// Build type_arguments vector (or null)
Label no_type_args;
__ ldr(R3, Address(THR, target::Thread::object_null_offset()), kEightBytes);
__ cmp(R4, Operand(0));
__ b(&no_type_args, EQ);
__ ldr(R0, Address(FP, kReceiverOffset * target::kWordSize));
__ LoadCompressed(R3, Address(R0, R4));
__ Bind(&no_type_args);
// Push type arguments.
__ Push(R3);
// Put function and context (receiver) in right registers for
// AllocateClosure stub.
__ MoveRegister(AllocateClosureABI::kFunctionReg, R1);
__ ldr(AllocateClosureABI::kContextReg,
Address(FP, target::kWordSize * kReceiverOffset));
// Allocate closure. After this point, we only use the registers in
// AllocateClosureABI.
__ LoadObject(CODE_REG, closure_allocation_stub);
__ ldr(AllocateClosureABI::kScratchReg,
FieldAddress(CODE_REG, target::Code::entry_point_offset()));
__ blr(AllocateClosureABI::kScratchReg);
// Populate closure object.
__ Pop(AllocateClosureABI::kScratchReg); // Pop type arguments.
__ StoreCompressedIntoObjectNoBarrier(
AllocateClosureABI::kResultReg,
FieldAddress(AllocateClosureABI::kResultReg,
target::Closure::instantiator_type_arguments_offset()),
AllocateClosureABI::kScratchReg);
// Keep delayed_type_arguments as null if non-generic (see Closure::New).
if (generic) {
__ LoadObject(AllocateClosureABI::kScratchReg, EmptyTypeArguments());
__ StoreCompressedIntoObjectNoBarrier(
AllocateClosureABI::kResultReg,
FieldAddress(AllocateClosureABI::kResultReg,
target::Closure::delayed_type_arguments_offset()),
AllocateClosureABI::kScratchReg);
}
__ LeaveStubFrame();
// No-op if the two are the same.
__ MoveRegister(R0, AllocateClosureABI::kResultReg);
__ Ret();
}
void StubCodeCompiler::GenerateDispatchTableNullErrorStub() {
__ EnterStubFrame();
__ SmiTag(DispatchTableNullErrorABI::kClassIdReg);
__ PushRegister(DispatchTableNullErrorABI::kClassIdReg);
__ CallRuntime(kDispatchTableNullErrorRuntimeEntry, /*argument_count=*/1);
// The NullError runtime entry does not return.
__ Breakpoint();
}
void StubCodeCompiler::GenerateRangeError(bool with_fpu_regs) {
auto perform_runtime_call = [&]() {
// If the generated code has unboxed index/length we need to box them before
// calling the runtime entry.
if (GenericCheckBoundInstr::UseUnboxedRepresentation()) {
Label length, smi_case;
// The user-controlled index might not fit into a Smi.
#if !defined(DART_COMPRESSED_POINTERS)
__ adds(RangeErrorABI::kIndexReg, RangeErrorABI::kIndexReg,
compiler::Operand(RangeErrorABI::kIndexReg));
__ BranchIf(NO_OVERFLOW, &length);
#else
__ mov(TMP, RangeErrorABI::kIndexReg);
__ SmiTag(RangeErrorABI::kIndexReg);
__ sxtw(RangeErrorABI::kIndexReg, RangeErrorABI::kIndexReg);
__ cmp(TMP,
compiler::Operand(RangeErrorABI::kIndexReg, ASR, kSmiTagSize));
__ BranchIf(EQ, &length);
#endif
{
// Allocate a mint, reload the two registers and populate the mint.
__ PushRegister(NULL_REG);
__ CallRuntime(kAllocateMintRuntimeEntry, /*argument_count=*/0);
__ PopRegister(RangeErrorABI::kIndexReg);
__ ldr(TMP,
Address(FP, target::kWordSize *
StubCodeCompiler::WordOffsetFromFpToCpuRegister(
RangeErrorABI::kIndexReg)));
__ str(TMP, FieldAddress(RangeErrorABI::kIndexReg,
target::Mint::value_offset()));
__ ldr(RangeErrorABI::kLengthReg,
Address(FP, target::kWordSize *
StubCodeCompiler::WordOffsetFromFpToCpuRegister(
RangeErrorABI::kLengthReg)));
}
// Length is guaranteed to be in positive Smi range (it comes from a load
// of a vm recognized array).
__ Bind(&length);
__ SmiTag(RangeErrorABI::kLengthReg);
}
__ PushRegistersInOrder(
{RangeErrorABI::kLengthReg, RangeErrorABI::kIndexReg});
__ CallRuntime(kRangeErrorRuntimeEntry, /*argument_count=*/2);
__ Breakpoint();
};
GenerateSharedStubGeneric(
/*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);
}
void StubCodeCompiler::GenerateWriteError(bool with_fpu_regs) {
auto perform_runtime_call = [&]() {
__ CallRuntime(kWriteErrorRuntimeEntry, /*argument_count=*/0);
__ Breakpoint();
};
GenerateSharedStubGeneric(
/*save_fpu_registers=*/with_fpu_regs,
with_fpu_regs
? target::Thread::write_error_shared_with_fpu_regs_stub_offset()
: target::Thread::write_error_shared_without_fpu_regs_stub_offset(),
/*allow_return=*/false, perform_runtime_call);
}
// Input parameters:
// LR : return address.
// SP : address of return value.
// R5 : 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(R6, target::Thread::exit_through_runtime_call());
__ StoreToOffset(R6, THR, target::Thread::exit_through_ffi_offset());
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R6, THR, target::Thread::vm_tag_offset());
__ CompareImmediate(R6, VMTag::kDartTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Mark that the thread is executing native code.
__ StoreToOffset(R5, THR, target::Thread::vm_tag_offset());
WithExceptionCatchingTrampoline(assembler, [&]() {
// 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, THR);
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);
__ AddImmediate(
R3, FP,
(target::frame_layout.param_end_from_fp + 1) * 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.
__ StoreToOffset(R0, SP, thread_offset);
__ StoreToOffset(R1, SP, argc_tag_offset);
__ StoreToOffset(R2, SP, argv_offset);
__ StoreToOffset(R3, SP, retval_offset);
__ mov(R0, SP); // Pass the pointer to the target::NativeArguments.
// We are entering runtime code, so the C stack pointer must be restored
// from the stack limit to the top of the stack. We cache the stack limit
// address in the Dart SP register, which is callee-saved in the C ABI.
__ mov(R25, CSP);
__ mov(CSP, SP);
__ mov(R1, R5); // Pass the function entrypoint to call.
// Call native function invocation wrapper or redirection via simulator.
__ Call(wrapper);
// Restore SP and CSP.
__ mov(SP, CSP);
__ mov(CSP, R25);
// Refresh pinned registers (write barrier mask, null, dispatch table, etc).
__ RestorePinnedRegisters();
// 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.
__ StoreToOffset(ZR, THR, target::Thread::exit_through_ffi_offset());
// Reset exit frame information in Isolate's mutator thread structure.
__ StoreToOffset(ZR, 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) {
__ SetupGlobalPoolAndDispatchTable();
}
});
__ LeaveStubFrame();
__ ret();
}
void StubCodeCompiler::GenerateCallNoScopeNativeStub() {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR,
target::Thread::no_scope_native_wrapper_entry_point_offset()));
}
void StubCodeCompiler::GenerateCallAutoScopeNativeStub() {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR,
target::Thread::auto_scope_native_wrapper_entry_point_offset()));
}
// Input parameters:
// LR : return address.
// SP : address of return value.
// R5 : 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() {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR,
target::Thread::bootstrap_native_wrapper_entry_point_offset()));
}
// Input parameters:
// ARGS_DESC_REG: arguments descriptor array.
void StubCodeCompiler::GenerateCallStaticFunctionStub() {
// 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.
__ Push(ARGS_DESC_REG);
__ Push(ZR);
__ CallRuntime(kPatchStaticCallRuntimeEntry, 0);
// Get Code object result and restore arguments descriptor array.
__ Pop(CODE_REG);
__ Pop(ARGS_DESC_REG);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(R0, CODE_REG, target::Code::entry_point_offset());
__ br(R0);
}
// Called from a static call only when an invalid code has been entered
// (invalid because its function was optimized or deoptimized).
// ARGS_DESC_REG: arguments descriptor array.
void StubCodeCompiler::GenerateFixCallersTargetStub() {
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.
__ Push(ARGS_DESC_REG);
__ Push(ZR);
__ CallRuntime(kFixCallersTargetRuntimeEntry, 0);
// Get Code object result and restore arguments descriptor array.
__ Pop(CODE_REG);
__ Pop(ARGS_DESC_REG);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(R0, CODE_REG, target::Code::entry_point_offset());
__ br(R0);
__ 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();
__ Push(ZR); // Result slot.
__ Push(R0); // Preserve receiver.
__ Push(R5); // Old cache value (also 2nd return value).
__ CallRuntime(kFixCallersTargetMonomorphicRuntimeEntry, 2);
__ Pop(R5); // Get target cache object.
__ Pop(R0); // Restore receiver.
__ Pop(CODE_REG); // Get target Code object.
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(
R1, CODE_REG,
target::Code::entry_point_offset(CodeEntryKind::kMonomorphic));
__ br(R1);
}
// Called from object allocate instruction when the allocation stub has been
// disabled.
void StubCodeCompiler::GenerateFixAllocationStubTargetStub() {
// 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.
__ Push(ZR);
__ CallRuntime(kFixAllocationStubTargetRuntimeEntry, 0);
// Get Code object result.
__ Pop(CODE_REG);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(R0, CODE_REG, target::Code::entry_point_offset());
__ br(R0);
}
// Called from object allocate instruction when the allocation stub for a
// generic class has been disabled.
void StubCodeCompiler::GenerateFixParameterizedAllocationStubTargetStub() {
// 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();
// Preserve type arguments register.
__ Push(AllocateObjectABI::kTypeArgumentsReg);
// Setup space on stack for return value.
__ Push(ZR);
__ CallRuntime(kFixAllocationStubTargetRuntimeEntry, 0);
// Get Code object result.
__ Pop(CODE_REG);
// Restore type arguments register.
__ Pop(AllocateObjectABI::kTypeArgumentsReg);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(R0, CODE_REG, target::Code::entry_point_offset());
__ br(R0);
}
// 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.
__ SmiUntag(R2);
__ add(R1, FP, Operand(R2, LSL, target::kWordSizeLog2));
__ AddImmediate(R1,
target::frame_layout.param_end_from_fp * target::kWordSize);
__ AddImmediate(R3, R0, target::Array::data_offset() - kHeapObjectTag);
// R1: address of first argument on stack.
// R3: address of first argument in array.
Label loop, loop_exit;
__ Bind(&loop);
__ CompareRegisters(R2, ZR);
__ b(&loop_exit, LE);
__ ldr(R7, Address(R1));
__ AddImmediate(R1, -target::kWordSize);
__ AddImmediate(R3, target::kCompressedWordSize);
__ AddImmediate(R2, R2, -1);
__ StoreCompressedIntoObject(R0, Address(R3, -target::kCompressedWordSize),
R7);
__ b(&loop);
__ Bind(&loop_exit);
}
// Used by eager and lazy deoptimization. Preserve result in RAX 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 TagAndPushPP() below:
// +------------------+
// | Saved PP | <- PP
// +------------------+
// | PC marker | <- TOS
// +------------------+
// | Saved FP | <- FP of stub
// +------------------+
// | return-address | (deoptimization point)
// +------------------+
// | 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.
__ EnterStubFrame();
// 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--) {
const Register r = static_cast<Register>(i);
if (r == CODE_REG) {
// Save the original value of CODE_REG pushed before invoking this stub
// instead of the value used to call this stub.
COMPILE_ASSERT(R25 > CODE_REG);
__ ldr(R25, Address(FP, 2 * target::kWordSize));
__ str(R25, Address(SP, -1 * target::kWordSize, Address::PreIndex));
} else if (r == R15) {
// Because we save registers in decreasing order, IP0 will already be
// saved.
COMPILE_ASSERT(IP0 == R16);
__ mov(IP0, R15);
__ str(IP0, Address(SP, -1 * target::kWordSize, Address::PreIndex));
} else if (r == R31) {
__ str(ZR, Address(SP, -1 * target::kWordSize, Address::PreIndex));
} else {
__ str(r, Address(SP, -1 * target::kWordSize, Address::PreIndex));
}
}
for (intptr_t reg_idx = kNumberOfVRegisters - 1; reg_idx >= 0; reg_idx--) {
VRegister vreg = static_cast<VRegister>(reg_idx);
__ PushQuad(vreg);
}
{
__ mov(R0, SP); // Pass address of saved registers block.
LeafRuntimeScope rt(assembler,
/*frame_size=*/0,
/*preserve_registers=*/false);
bool is_lazy =
(kind == kLazyDeoptFromReturn) || (kind == kLazyDeoptFromThrow);
__ LoadImmediate(R1, is_lazy ? 1 : 0);
rt.Call(kDeoptimizeCopyFrameRuntimeEntry, 2);
// Result (R0) is stack-size (FP - SP) in bytes.
}
if (kind == kLazyDeoptFromReturn) {
// Restore result into R1 temporarily.
__ LoadFromOffset(R1, FP, saved_result_slot_from_fp * target::kWordSize);
} else if (kind == kLazyDeoptFromThrow) {
// Restore result into R1 temporarily.
__ LoadFromOffset(R1, FP, saved_exception_slot_from_fp * target::kWordSize);
__ LoadFromOffset(R2, FP,
saved_stacktrace_slot_from_fp * target::kWordSize);
}
// There is a Dart Frame on the stack. We must restore PP and leave frame.
__ RestoreCodePointer();
__ LeaveStubFrame();
__ 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();
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.
}
{
__ mov(R0, FP); // Pass last FP as parameter in R0.
LeafRuntimeScope rt(assembler,
/*frame_size=*/0,
/*preserve_registers=*/false);
rt.Call(kDeoptimizeFillFrameRuntimeEntry, 1);
}
if (kind == kLazyDeoptFromReturn) {
// Restore result into R1.
__ LoadFromOffset(
R1, FP, target::frame_layout.first_local_from_fp * target::kWordSize);
} else if (kind == kLazyDeoptFromThrow) {
// Restore result into R1.
__ LoadFromOffset(
R1, FP, target::frame_layout.first_local_from_fp * target::kWordSize);
__ LoadFromOffset(
R2, FP,
(target::frame_layout.first_local_from_fp - 1) * target::kWordSize);
}
// Code above cannot cause GC.
// There is a Dart Frame on the stack. We must restore PP and leave frame.
__ 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.
}
__ Push(ZR); // 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);
__ SmiUntag(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));
// The caller is responsible for emitting the return instruction.
}
// R0: result, must be preserved
void StubCodeCompiler::GenerateDeoptimizeLazyFromReturnStub() {
// Push zap value instead of CODE_REG for lazy deopt.
__ LoadImmediate(TMP, kZapCodeReg);
__ Push(TMP);
// 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() {
// Push zap value instead of CODE_REG for lazy deopt.
__ LoadImmediate(TMP, kZapCodeReg);
__ Push(TMP);
// 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() {
__ Push(CODE_REG);
__ ldr(CODE_REG, Address(THR, target::Thread::deoptimize_stub_offset()));
GenerateDeoptimizationSequence(assembler, kEagerDeopt);
__ ret();
}
// IC_DATA_REG: ICData/MegamorphicCache
static void GenerateNoSuchMethodDispatcherBody(Assembler* assembler) {
__ EnterStubFrame();
__ ldr(ARGS_DESC_REG,
FieldAddress(IC_DATA_REG,
target::CallSiteData::arguments_descriptor_offset()));
// Load the receiver.
__ LoadCompressedSmiFieldFromOffset(
R2, ARGS_DESC_REG, target::ArgumentsDescriptor::size_offset());
__ add(TMP, FP, Operand(R2, LSL, target::kWordSizeLog2 - 1)); // R2 is Smi.
__ LoadFromOffset(R6, TMP,
target::frame_layout.param_end_from_fp * target::kWordSize);
__ Push(ZR); // Result slot.
__ Push(R6); // Receiver.
__ Push(IC_DATA_REG); // ICData/MegamorphicCache.
__ Push(ARGS_DESC_REG); // Arguments descriptor.
// Adjust arguments count.
__ LoadCompressedSmiFieldFromOffset(
R3, ARGS_DESC_REG, target::ArgumentsDescriptor::type_args_len_offset());
__ AddImmediate(TMP, R2, 1, kObjectBytes); // Include the type arguments.
__ cmp(R3, Operand(0), kObjectBytes);
// R2 <- (R3 == 0) ? R2 : TMP + 1 (R2 : R2 + 2).
__ csinc(R2, R2, TMP, EQ, kObjectBytes);
// 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:
// ARGS_DESC_REG - arguments descriptor
// IC_DATA_REG - icdata/megamorphic_cache
void StubCodeCompiler::GenerateNoSuchMethodDispatcherStub() {
GenerateNoSuchMethodDispatcherBody(assembler);
}
// Called for inline allocation of arrays.
// Input registers (preserved):
// LR: return address.
// AllocateArrayABI::kLengthReg: array length as Smi.
// AllocateArrayABI::kTypeArgumentsReg: type arguments of array.
// Output registers:
// AllocateArrayABI::kResultReg: newly allocated array.
// Clobbered:
// R3, R7
void StubCodeCompiler::GenerateAllocateArrayStub() {
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label slow_case;
// Compute the size to be allocated, it is based on the array length
// and is computed as:
// RoundedAllocationSize(
// (array_length * kCompressedWordSize) + target::Array::header_size()).
// Check that length is a Smi.
__ BranchIfNotSmi(AllocateArrayABI::kLengthReg, &slow_case);
// Check length >= 0 && length <= kMaxNewSpaceElements
const intptr_t max_len =
target::ToRawSmi(target::Array::kMaxNewSpaceElements);
__ CompareImmediate(AllocateArrayABI::kLengthReg, max_len, kObjectBytes);
__ b(&slow_case, HI);
const intptr_t cid = kArrayCid;
NOT_IN_PRODUCT(__ MaybeTraceAllocation(kArrayCid, &slow_case, R4));
// Calculate and align allocation size.
// Load new object start and calculate next object start.
// AllocateArrayABI::kTypeArgumentsReg: type arguments of array.
// AllocateArrayABI::kLengthReg: array length as Smi.
__ ldr(AllocateArrayABI::kResultReg,
Address(THR, target::Thread::top_offset()));
intptr_t fixed_size_plus_alignment_padding =
target::Array::header_size() +
target::ObjectAlignment::kObjectAlignment - 1;
__ LoadImmediate(R3, fixed_size_plus_alignment_padding);
// AllocateArrayABI::kLengthReg is Smi.
#if defined(DART_COMPRESSED_POINTERS)
__ add(R3, R3, Operand(AllocateArrayABI::kLengthReg, LSL, 1), kObjectBytes);
#else
__ add(R3, R3, Operand(AllocateArrayABI::kLengthReg, LSL, 2), kObjectBytes);
#endif
ASSERT(kSmiTagShift == 1);
__ andi(R3, R3,
Immediate(~(target::ObjectAlignment::kObjectAlignment - 1)));
// AllocateArrayABI::kResultReg: potential new object start.
// R3: object size in bytes.
__ adds(R7, R3, Operand(AllocateArrayABI::kResultReg));
__ b(&slow_case, CS); // Branch if unsigned overflow.
// Check if the allocation fits into the remaining space.
// AllocateArrayABI::kResultReg: potential new object start.
// AllocateArrayABI::kTypeArgumentsReg: type arguments of array.
// AllocateArrayABI::kLengthReg: array length as Smi.
// R3: array size.
// R7: potential next object start.
__ LoadFromOffset(TMP, THR, target::Thread::end_offset());
__ CompareRegisters(R7, TMP);
__ b(&slow_case, CS); // Branch if unsigned higher or equal.
__ CheckAllocationCanary(AllocateArrayABI::kResultReg);
// Successfully allocated the object(s), now update top to point to
// next object start and initialize the object.
// AllocateArrayABI::kResultReg: potential new object start.
// R3: array size.
// R7: potential next object start.
__ str(R7, Address(THR, target::Thread::top_offset()));
__ add(AllocateArrayABI::kResultReg, AllocateArrayABI::kResultReg,
Operand(kHeapObjectTag));
// AllocateArrayABI::kResultReg: new object start as a tagged pointer.
// AllocateArrayABI::kTypeArgumentsReg: type arguments of array.
// AllocateArrayABI::kLengthReg: array length as Smi.
// R3: array size.
// R7: new object end address.
// Store the type argument field.
__ StoreCompressedIntoObjectOffsetNoBarrier(
AllocateArrayABI::kResultReg, target::Array::type_arguments_offset(),
AllocateArrayABI::kTypeArgumentsReg);
// Set the length field.
__ StoreCompressedIntoObjectOffsetNoBarrier(AllocateArrayABI::kResultReg,
target::Array::length_offset(),
AllocateArrayABI::kLengthReg);
// Calculate the size tag.
// AllocateArrayABI::kResultReg: new object start as a tagged pointer.
// AllocateArrayABI::kLengthReg: array length as Smi.
// R3: array size.
// R7: new object end address.
const intptr_t shift = target::UntaggedObject::kTagBitsSizeTagPos -
target::ObjectAlignment::kObjectAlignmentLog2;
__ CompareImmediate(R3, target::UntaggedObject::kSizeTagMaxSizeTag);
// If no size tag overflow, shift R3 left, else set R3 to zero.
__ LslImmediate(TMP, R3, shift);
__ csel(R3, TMP, R3, LS);
__ csel(R3, ZR, R3, HI);
// Get the class index and insert it into the tags.
const uword tags =
target::MakeTagWordForNewSpaceObject(cid, /*instance_size=*/0);
__ LoadImmediate(TMP, tags);
__ orr(R3, R3, Operand(TMP));
__ StoreFieldToOffset(R3, AllocateArrayABI::kResultReg,
target::Array::tags_offset());
// Initialize all array elements to raw_null.
// AllocateArrayABI::kResultReg: new object start as a tagged pointer.
// R7: new object end address.
// AllocateArrayABI::kLengthReg: array length as Smi.
__ AddImmediate(R3, AllocateArrayABI::kResultReg,
target::Array::data_offset() - kHeapObjectTag);
// R3: iterator which initially points to the start of the variable
// data area to be initialized.
#if defined(DART_COMPRESSED_POINTERS)
const Register kWordOfNulls = TMP;
__ andi(kWordOfNulls, NULL_REG, Immediate(0xFFFFFFFF));
__ orr(kWordOfNulls, kWordOfNulls, Operand(kWordOfNulls, LSL, 32));
#else
const Register kWordOfNulls = NULL_REG;
#endif
Label loop;
__ Bind(&loop);
ASSERT(target::kObjectAlignment == 2 * target::kWordSize);
__ stp(kWordOfNulls, kWordOfNulls,
Address(R3, 2 * target::kWordSize, Address::PairPostIndex));
// Safe to only check every kObjectAlignment bytes instead of each word.
ASSERT(kAllocationRedZoneSize >= target::kObjectAlignment);
__ CompareRegisters(R3, R7);
__ b(&loop, UNSIGNED_LESS);
__ WriteAllocationCanary(R7); // Fix overshoot.
// Done allocating and initializing the array.
// AllocateArrayABI::kResultReg: new object.
// AllocateArrayABI::kLengthReg: array length as Smi (preserved).
__ ret();
// 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();
// Setup space on stack for return value.
// Push array length as Smi and element type.
__ Push(ZR);
__ Push(AllocateArrayABI::kLengthReg);
__ Push(AllocateArrayABI::kTypeArgumentsReg);
__ CallRuntime(kAllocateArrayRuntimeEntry, 2);
// 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.
__ ldr(AllocateArrayABI::kResultReg, Address(SP, 2 * target::kWordSize));
EnsureIsNewOrRemembered();
// Pop arguments; result is popped in IP.
__ Pop(AllocateArrayABI::kTypeArgumentsReg);
__ Pop(AllocateArrayABI::kLengthReg);
__ Pop(AllocateArrayABI::kResultReg);
__ LeaveStubFrame();
__ ret();
}
void StubCodeCompiler::GenerateAllocateMintSharedWithFPURegsStub() {
// For test purpose call allocation stub without inline allocation attempt.
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label slow_case;
__ TryAllocate(compiler::MintClass(), &slow_case, Assembler::kNearJump,
AllocateMintABI::kResultReg, AllocateMintABI::kTempReg);
__ Ret();
__ Bind(&slow_case);
}
COMPILE_ASSERT(AllocateMintABI::kResultReg ==
SharedSlowPathStubABI::kResultReg);
GenerateSharedStub(/*save_fpu_registers=*/true, &kAllocateMintRuntimeEntry,
target::Thread::allocate_mint_with_fpu_regs_stub_offset(),
/*allow_return=*/true,
/*store_runtime_result_in_result_register=*/true);
}
void StubCodeCompiler::GenerateAllocateMintSharedWithoutFPURegsStub() {
// For test purpose call allocation stub without inline allocation attempt.
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label slow_case;
__ TryAllocate(compiler::MintClass(), &slow_case, Assembler::kNearJump,
AllocateMintABI::kResultReg, AllocateMintABI::kTempReg);
__ Ret();
__ Bind(&slow_case);
}
COMPILE_ASSERT(AllocateMintABI::kResultReg ==
SharedSlowPathStubABI::kResultReg);
GenerateSharedStub(
/*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 : target code or entry point (in bare instructions mode).
// R1 : arguments descriptor array.
// R2 : arguments array.
// R3 : current thread.
void StubCodeCompiler::GenerateInvokeDartCodeStub() {
__ Comment("InvokeDartCodeStub");
// Copy the C stack pointer (CSP/R31) into the stack pointer we'll actually
// use to access the stack (SP/R15) and set the C stack pointer to near the
// stack limit, loaded from the Thread held in R3, to prevent signal handlers
// from over-writing Dart frames.
__ mov(SP, CSP);
__ SetupCSPFromThread(R3);
__ EnterFrame(0);
// Push code object to PC marker slot.
__ ldr(TMP, Address(R3, target::Thread::invoke_dart_code_stub_offset()));
__ Push(TMP);
#if defined(DART_TARGET_OS_FUCHSIA)
__ str(R18, Address(R3, target::Thread::saved_shadow_call_stack_offset()));
#elif defined(USING_SHADOW_CALL_STACK)
#error Unimplemented
#endif
__ PushNativeCalleeSavedRegisters();
// Set up THR, which caches the current thread in Dart code.
if (THR != R3) {
__ mov(THR, R3);
}
// Refresh pinned registers (write barrier mask, null, dispatch table, etc).
__ RestorePinnedRegisters();
// Save the current VMTag on the stack.
__ LoadFromOffset(R4, THR, target::Thread::vm_tag_offset());
__ Push(R4);
// Save top resource and top exit frame info. Use R6 as a temporary register.
// StackFrameIterator reads the top exit frame info saved in this frame.
__ LoadFromOffset(R6, THR, target::Thread::top_resource_offset());
__ StoreToOffset(ZR, THR, target::Thread::top_resource_offset());
__ Push(R6);
__ LoadFromOffset(R6, THR, target::Thread::exit_through_ffi_offset());
__ Push(R6);
__ StoreToOffset(ZR, THR, target::Thread::exit_through_ffi_offset());
__ LoadFromOffset(R6, THR, target::Thread::top_exit_frame_info_offset());
__ StoreToOffset(ZR, 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(DART_TARGET_OS_FUCHSIA)
ASSERT(target::frame_layout.exit_link_slot_from_entry_fp == -24);
#else
ASSERT(target::frame_layout.exit_link_slot_from_entry_fp == -23);
#endif
__ Push(R6);
// In debug mode, verify that we've pushed the top exit frame info at the
// correct offset from FP.
__ EmitEntryFrameVerification();
// Mark that the thread is executing Dart code. Do this after initializing the
// exit link for the profiler.
__ LoadImmediate(R6, VMTag::kDartTagId);
__ StoreToOffset(R6, THR, target::Thread::vm_tag_offset());
// Load arguments descriptor array into R4, which is passed to Dart code.
__ mov(R4, R1);
// Load number of arguments into R5 and adjust count for type arguments.
__ LoadCompressedSmiFieldFromOffset(
R5, R4, target::ArgumentsDescriptor::count_offset());
__ LoadCompressedSmiFieldFromOffset(
R3, R4, target::ArgumentsDescriptor::type_args_len_offset());
__ SmiUntag(R5);
// Include the type arguments.
__ cmp(R3, Operand(0), kObjectBytes);
__ csinc(R5, R5, R5, EQ); // R5 <- (R3 == 0) ? R5 : R5 + 1
// Compute address of 'arguments array' data area into R2.
__ AddImmediate(R2, R2, target::Array::data_offset() - kHeapObjectTag);
// Set up arguments for the Dart call.
Label push_arguments;
Label done_push_arguments;
__ cmp(R5, Operand(0));
__ b(&done_push_arguments, EQ); // check if there are arguments.
__ LoadImmediate(R1, 0);
__ Bind(&push_arguments);
__ LoadCompressed(R3, Address(R2));
__ Push(R3);
__ add(R1, R1, Operand(1));
__ add(R2, R2, Operand(target::kCompressedWordSize));
__ cmp(R1, Operand(R5));
__ b(&push_arguments, LT);
__ Bind(&done_push_arguments);
if (FLAG_precompiled_mode) {
__ SetupGlobalPoolAndDispatchTable();
__ mov(CODE_REG, ZR); // GC-safe value into CODE_REG.
} else {
// We now load the pool pointer(PP) with a GC safe value as we are about to
// invoke dart code. We don't need a real object pool here.
// Smi zero does not work because ARM64 assumes PP to be untagged.
__ LoadObject(PP, NullObject());
__ mov(CODE_REG, R0);
__ ldr(R0, FieldAddress(CODE_REG, target::Code::entry_point_offset()));
}
// Call the Dart code entrypoint.
__ blr(R0); // R4 is the arguments descriptor array.
__ Comment("InvokeDartCodeStub return");
// 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 R6 as a temporary register for this.
__ Pop(R6);
__ StoreToOffset(R6, THR, target::Thread::top_exit_frame_info_offset());
__ Pop(R6);
__ StoreToOffset(R6, THR, target::Thread::exit_through_ffi_offset());
__ Pop(R6);
__ StoreToOffset(R6, THR, target::Thread::top_resource_offset());
// Restore the current VMTag from the stack.
__ Pop(R4);
__ StoreToOffset(R4, THR, target::Thread::vm_tag_offset());
__ PopNativeCalleeSavedRegisters();
// Restore the frame pointer and C stack pointer and return.
__ LeaveFrame();
__ RestoreCSP();
__ 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, R4, TMP
static void GenerateAllocateContextSpaceStub(Assembler* assembler,
Label* slow_case) {
// First compute the rounded instance size.
// R1: number of context variables.
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, kCompressedWordSizeLog2));
ASSERT(kSmiTagShift == 1);
__ andi(R2, R2, Immediate(~(target::ObjectAlignment::kObjectAlignment - 1)));
NOT_IN_PRODUCT(__ MaybeTraceAllocation(kContextCid, slow_case, R4));
// 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(TMP, Address(THR, target::Thread::end_offset()));
__ CompareRegisters(R3, TMP);
__ b(slow_case, CS); // Branch if unsigned higher or equal.
__ CheckAllocationCanary(R0);
// Successfully allocated the object, now update top to point to
// next object start and initialize the object.
// R0: new object.
// 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.
// R1: number of context variables.
// R2: object size.
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.
__ LslImmediate(TMP, R2, shift);
__ csel(R2, TMP, R2, LS);
__ csel(R2, ZR, R2, HI);
// Get the class index and insert it into the tags.
// R2: size and bit tags.
const uword tags =
target::MakeTagWordForNewSpaceObject(kContextCid, /*instance_size=*/0);
__ LoadImmediate(TMP, tags);
__ orr(R2, R2, Operand(TMP));
__ StoreFieldToOffset(R2, 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).
__ StoreFieldToOffset(R1, R0, target::Context::num_variables_offset(),
kFourBytes);
}
// Called for inline allocation of contexts.
// Input:
// R1: number of context variables.
// Output:
// R0: new allocated Context object.
// Clobbered:
// R2, R3, R4, TMP
void StubCodeCompiler::GenerateAllocateContextStub() {
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label slow_case;
GenerateAllocateContextSpaceStub(assembler, &slow_case);
// Setup the parent field.
// R0: new object.
// R1: number of context variables.
__ StoreCompressedIntoObjectOffset(R0, target::Context::parent_offset(),
NULL_REG);
// Initialize the context variables.
// R0: new object.
// R1: number of context variables.
__ AddImmediate(R3, R0,
target::Context::variable_offset(0) - kHeapObjectTag);
#if defined(DART_COMPRESSED_POINTERS)
const Register kWordOfNulls = TMP;
__ andi(kWordOfNulls, NULL_REG, Immediate(0xFFFFFFFF));
__ orr(kWordOfNulls, kWordOfNulls, Operand(kWordOfNulls, LSL, 32));
#else
const Register kWordOfNulls = NULL_REG;
#endif
Label loop;
__ Bind(&loop);
ASSERT(target::kObjectAlignment == 2 * target::kWordSize);
__ stp(kWordOfNulls, kWordOfNulls,
Address(R3, 2 * target::kWordSize, Address::PairPostIndex));
// Safe to only check every kObjectAlignment bytes instead of each word.
ASSERT(kAllocationRedZoneSize >= target::kObjectAlignment);
__ subs(R1, R1,
Operand(target::kObjectAlignment / target::kCompressedWordSize));
__ b(&loop, HI);
#if defined(DEBUG)
__ ldr(TMP2, Address(THR, target::Thread::top_offset()));
__ WriteAllocationCanary(TMP2); // Fix overshoot.
#endif
// 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.
__ SmiTag(R1);
__ PushObject(NullObject());
__ Push(R1);
__ 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();
// R0: new object
// Restore the frame pointer.
__ LeaveStubFrame();
__ ret();
}
// Called for clone of contexts.
// Input:
// R5: context variable to clone.
// Output:
// R0: new allocated Context object.
// Clobbered:
// R1, (R2), R3, R4, (TMP)
void StubCodeCompiler::GenerateCloneContextStub() {
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label slow_case;
// Load num. variable (int32) in the existing context.
__ ldr(R1, FieldAddress(R5, target::Context::num_variables_offset()),
kFourBytes);
GenerateAllocateContextSpaceStub(assembler, &slow_case);
// Load parent in the existing context.
__ LoadCompressed(R3, FieldAddress(R5, target::Context::parent_offset()));
// Setup the parent field.
// R0: new context.
__ StoreCompressedIntoObjectNoBarrier(
R0, FieldAddress(R0, target::Context::parent_offset()), R3);
// Clone the context variables.
// R0: new context.
// R1: number of context variables.
{
Label loop, done;
// R3: Variable array address, new context.
__ AddImmediate(R3, R0,
target::Context::variable_offset(0) - kHeapObjectTag);
// R4: Variable array address, old context.
__ AddImmediate(R4, R5,
target::Context::variable_offset(0) - kHeapObjectTag);
__ Bind(&loop);
__ subs(R1, R1, Operand(1));
__ b(&done, MI);
__ ldr(R5, Address(R4, R1, UXTX, Address::Scaled), kObjectBytes);
__ str(R5, Address(R3, R1, UXTX, Address::Scaled), kObjectBytes);
__ 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.
__ PushPair(R5, NULL_REG);
__ CallRuntime(kCloneContextRuntimeEntry, 1); // Clone context.
// Pop number of context variables argument.
// Pop the new context object.
__ PopPair(R1, 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();
// R0: new object
// Restore the frame pointer.
__ LeaveStubFrame();
__ ret();
}
void StubCodeCompiler::GenerateWriteBarrierWrappersStub() {
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(__ Push(LR));
__ Push(kWriteBarrierObjectReg);
__ mov(kWriteBarrierObjectReg, reg);
__ Call(Address(THR, target::Thread::write_barrier_entry_point_offset()));
__ Pop(kWriteBarrierObjectReg);
RESTORES_LR_FROM_FRAME(__ Pop(LR));
READS_RETURN_ADDRESS_FROM_LR(__ ret(LR));
intptr_t end = __ CodeSize();
RELEASE_ASSERT(end - start == kStoreBufferWrapperSize);
}
}
// Helper stub to implement Assembler::StoreIntoObject/Array.
// Input parameters:
// R1: Object (old)
// R0: Value (old or new)
// R25: 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 == R25);
static void GenerateWriteBarrierStubHelper(Assembler* assembler,
bool cards) {
RegisterSet spill_set((1 << R2) | (1 << R3) | (1 << R4), 0);
Label skip_marking;
__ ldr(TMP, FieldAddress(R0, target::Object::tags_offset()));
__ ldr(TMP2, Address(THR, target::Thread::write_barrier_mask_offset()));
__ and_(TMP, TMP, Operand(TMP2));
__ tsti(TMP, Immediate(target::UntaggedObject::kIncrementalBarrierMask));
__ b(&skip_marking, ZERO);
{
// Atomically clear kNotMarkedBit.
Label retry, done;
__ PushRegisters(spill_set);
__ AddImmediate(R3, R0, target::Object::tags_offset() - kHeapObjectTag);
// R3: Untagged address of header word (atomics do not support offsets).
if (TargetCPUFeatures::atomic_memory_supported()) {
__ LoadImmediate(TMP, 1 << target::UntaggedObject::kNotMarkedBit);
__ ldclr(TMP, TMP, R3);
__ tbz(&done, TMP, target::UntaggedObject::kNotMarkedBit);
} else {
__ Bind(&retry);
__ ldxr(R2, R3, kEightBytes);
__ tbz(&done, R2, target::UntaggedObject::kNotMarkedBit);
__ AndImmediate(R2, R2, ~(1 << target::UntaggedObject::kNotMarkedBit));
__ stxr(R4, R2, R3, kEightBytes);
__ cbnz(&retry, R4);
}
__ LoadFromOffset(R4, THR, target::Thread::marking_stack_block_offset());
__ LoadFromOffset(R2, R4, target::MarkingStackBlock::top_offset(),
kUnsignedFourBytes);
__ add(R3, R4, Operand(R2, LSL, target::kWordSizeLog2));
__ StoreToOffset(R0, R3, target::MarkingStackBlock::pointers_offset());
__ add(R2, R2, Operand(1));
__ StoreToOffset(R2, R4, target::MarkingStackBlock::top_offset(),
kUnsignedFourBytes);
__ CompareImmediate(R2, target::MarkingStackBlock::kSize);
__ b(&done, NE);
{
LeafRuntimeScope rt(assembler,
/*frame_size=*/0,
/*preserve_registers=*/true);
__ mov(R0, THR);
rt.Call(kMarkingStackBlockProcessRuntimeEntry, /*argument_count=*/1);
}
__ Bind(&done);
__ clrex();
__ PopRegisters(spill_set);
}
Label add_to_remembered_set, remember_card;
__ Bind(&skip_marking);
__ ldr(TMP, FieldAddress(R1, target::Object::tags_offset()));
__ ldr(TMP2, FieldAddress(R0, target::Object::tags_offset()));
__ and_(TMP, TMP2,
Operand(TMP, LSR, target::UntaggedObject::kBarrierOverlapShift));
__ tsti(TMP, Immediate(target::UntaggedObject::kGenerationalBarrierMask));
__ b(&add_to_remembered_set, NOT_ZERO);
__ ret();
__ Bind(&add_to_remembered_set);
if (cards) {
__ LoadFieldFromOffset(TMP, R1, target::Object::tags_offset(), kFourBytes);
__ tbnz(&remember_card, TMP, target::UntaggedObject::kCardRememberedBit);
} else {
#if defined(DEBUG)
Label ok;
__ LoadFieldFromOffset(TMP, R1, target::Object::tags_offset(), kFourBytes);
__ tbz(&ok, TMP, target::UntaggedObject::kCardRememberedBit);
__ Stop("Wrong barrier");
__ Bind(&ok);
#endif
}
{
// Atomically clear kOldAndNotRememberedBit.
Label retry, done;
__ PushRegisters(spill_set);
__ AddImmediate(R3, R1, target::Object::tags_offset() - kHeapObjectTag);
// R3: Untagged address of header word (atomics do not support offsets).
if (TargetCPUFeatures::atomic_memory_supported()) {
__ LoadImmediate(TMP,
1 << target::UntaggedObject::kOldAndNotRememberedBit);
__ ldclr(TMP, TMP, R3);
__ tbz(&done, TMP, target::UntaggedObject::kOldAndNotRememberedBit);
} else {
__ Bind(&retry);
__ ldxr(R2, R3, kEightBytes);
__ tbz(&done, R2, target::UntaggedObject::kOldAndNotRememberedBit);
__ AndImmediate(R2, R2,
~(1 << target::UntaggedObject::kOldAndNotRememberedBit));
__ stxr(R4, R2, R3, kEightBytes);
__ cbnz(&retry, R4);
}
// Load the StoreBuffer block out of the thread. Then load top_ out of the
// StoreBufferBlock and add the address to the pointers_.
__ LoadFromOffset(R4, THR, target::Thread::store_buffer_block_offset());
__ LoadFromOffset(R2, R4, target::StoreBufferBlock::top_offset(),
kUnsignedFourBytes);
__ add(R3, R4, Operand(R2, LSL, target::kWordSizeLog2));
__ StoreToOffset(R1, R3, target::StoreBufferBlock::pointers_offset());
// Increment top_ and check for overflow.
// R2: top_.
// R4: StoreBufferBlock.
__ add(R2, R2, Operand(1));
__ StoreToOffset(R2, R4, target::StoreBufferBlock::top_offset(),
kUnsignedFourBytes);
__ CompareImmediate(R2, target::StoreBufferBlock::kSize);
__ b(&done, NE);
{
LeafRuntimeScope rt(assembler,
/*frame_size=*/0,
/*preserve_registers=*/true);
__ mov(R0, THR);
rt.Call(kStoreBufferBlockProcessRuntimeEntry, /*argument_count=*/1);
}
__ Bind(&done);
__ PopRegisters(spill_set);
__ ret();
}
if (cards) {
Label remember_card_slow;
// Get card table.
__ Bind(&remember_card);
__ AndImmediate(TMP, R1, target::kPageMask); // Page.
__ ldr(TMP2,
Address(TMP, target::Page::card_table_offset())); // Card table.
__ cbz(&remember_card_slow, TMP2);
// Dirty the card. Not atomic: we assume mutable arrays are not shared
// between threads.
__ sub(R25, R25, Operand(TMP)); // Offset in page.
__ LsrImmediate(R25, R25, target::Page::kBytesPerCardLog2); // Index.
__ LoadImmediate(TMP, 1);
__ lslv(TMP, TMP, R25); // Bit mask. (Shift amount is mod 64.)
__ LsrImmediate(R25, R25, target::kBitsPerWordLog2); // Word index.
__ add(TMP2, TMP2, Operand(R25, LSL, target::kWordSizeLog2)); // Word addr.
__ ldr(R25, Address(TMP2, 0));
__ orr(R25, R25, Operand(TMP));
__ str(R25, Address(TMP2, 0));
__ ret();
// Card table not yet allocated.
__ Bind(&remember_card_slow);
{
LeafRuntimeScope rt(assembler,
/*frame_size=*/0,
/*preserve_registers=*/true);
__ mov(R0, R1); // Arg0 = Object
__ mov(R1, R25); // Arg1 = Slot
rt.Call(kRememberCardRuntimeEntry, /*argument_count=*/2);
}
__ ret();
}
}
void StubCodeCompiler::GenerateWriteBarrierStub() {
GenerateWriteBarrierStubHelper(assembler, false);
}
void StubCodeCompiler::GenerateArrayWriteBarrierStub() {
GenerateWriteBarrierStubHelper(assembler, true);
}
static void GenerateAllocateObjectHelper(Assembler* assembler,
bool is_cls_parameterized) {
const Register kTagsReg = AllocateObjectABI::kTagsReg;
{
Label slow_case;
#if !defined(PRODUCT)
{
const Register kTraceAllocationTempReg = R8;
const Register kCidRegister = R9;
__ ExtractClassIdFromTags(kCidRegister, AllocateObjectABI::kTagsReg);
__ MaybeTraceAllocation(kCidRegister, &slow_case,
kTraceAllocationTempReg);
}
#endif
const Register kNewTopReg = R3;
// Bump allocation.
{
const Register kInstanceSizeReg = R4;
const Register kEndReg = R5;
__ ExtractInstanceSizeFromTags(kInstanceSizeReg, kTagsReg);
// Load two words from Thread::top: top and end.
// AllocateObjectABI::kResultReg: potential next object start.
__ ldp(AllocateObjectABI::kResultReg, kEndReg,
Address(THR, target::Thread::top_offset(), Address::PairOffset));
__ add(kNewTopReg, AllocateObjectABI::kResultReg,
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()));
} // kInstanceSizeReg = R4, kEndReg = R5
// Tags.
__ str(kTagsReg, Address(AllocateObjectABI::kResultReg,
target::Object::tags_offset()));
// Initialize the remaining words of the object.
{
const Register kFieldReg = R4;
__ AddImmediate(kFieldReg, AllocateObjectABI::kResultReg,
target::Instance::first_field_offset());
#if defined(DART_COMPRESSED_POINTERS)
const Register kWordOfNulls = TMP;
__ andi(kWordOfNulls, NULL_REG, Immediate(0xFFFFFFFF));
__ orr(kWordOfNulls, kWordOfNulls, Operand(kWordOfNulls, LSL, 32));
#else
const Register kWordOfNulls = NULL_REG;
#endif
Label loop;
__ Bind(&loop);
ASSERT(target::kObjectAlignment == 2 * target::kWordSize);
__ stp(kWordOfNulls, kWordOfNulls,
Address(kFieldReg, 2 * target::kWordSize, Address::PairPostIndex));
// Safe to only check every kObjectAlignment bytes instead of each word.
ASSERT(kAllocationRedZoneSize >= target::kObjectAlignment);
__ CompareRegisters(kFieldReg, kNewTopReg);
__ b(&loop, UNSIGNED_LESS);
__ WriteAllocationCanary(kNewTopReg); // Fix overshoot.
} // kFieldReg = R4
if (is_cls_parameterized) {
Label not_parameterized_case;
const Register kClsIdReg = R4;
const Register kTypeOffsetReg = R5;
__ ExtractClassIdFromTags(kClsIdReg, kTagsReg);
// Load class' type_arguments_field offset in words.
__ LoadClassById(kTypeOffsetReg, kClsIdReg);
__ ldr(
kTypeOffsetReg,
FieldAddress(kTypeOffsetReg,
target::Class::
host_type_arguments_field_offset_in_words_offset()),
kFourBytes);
// Set the type arguments in the new object.
__ StoreCompressedIntoObjectNoBarrier(
AllocateObjectABI::kResultReg,
Address(AllocateObjectABI::kResultReg, kTypeOffsetReg, UXTX,
Address::Scaled),
AllocateObjectABI::kTypeArgumentsReg);
__ Bind(&not_parameterized_case);
} // kClsIdReg = R4, kTypeOffsetReg = R5
__ AddImmediate(AllocateObjectABI::kResultReg,
AllocateObjectABI::kResultReg, kHeapObjectTag);
__ ret();
__ Bind(&slow_case);
} // kNewTopReg = R3
// Fall back on slow case:
if (!is_cls_parameterized) {
__ mov(AllocateObjectABI::kTypeArgumentsReg, NULL_REG);
}
// Tail call to generic allocation stub.
__ ldr(
R3,
Address(THR, target::Thread::allocate_object_slow_entry_point_offset()));
__ br(R3);
}
// Called for inline allocation of objects (any class).
void StubCodeCompiler::GenerateAllocateObjectStub() {
GenerateAllocateObjectHelper(assembler, /*is_cls_parameterized=*/false);
}
void StubCodeCompiler::GenerateAllocateObjectParameterizedStub() {
GenerateAllocateObjectHelper(assembler, /*is_cls_parameterized=*/true);
}
void StubCodeCompiler::GenerateAllocateObjectSlowStub() {
if (!FLAG_precompiled_mode) {
__ ldr(CODE_REG,
Address(THR, target::Thread::call_to_runtime_stub_offset()));
}
__ ExtractClassIdFromTags(AllocateObjectABI::kTagsReg,
AllocateObjectABI::kTagsReg);
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
__ LoadClassById(R0, AllocateObjectABI::kTagsReg);
__ PushPair(R0, NULL_REG); // Pushes result slot, then class object.
// Should be Object::null() if class is non-parameterized.
__ Push(AllocateObjectABI::kTypeArgumentsReg);
__ CallRuntime(kAllocateObjectRuntimeEntry, 2);
// Load result off the stack into result register.
__ ldr(AllocateObjectABI::kResultReg, 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();
__ LeaveStubFrame();
__ ret();
}
// Called for inline allocation of objects.
void StubCodeCompiler::GenerateAllocationStubForClass(
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);
// 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);
const uword tags =
target::MakeTagWordForNewSpaceObject(cls_id, instance_size);
// Note: Keep in sync with helper function.
const Register kTagsReg = AllocateObjectABI::kTagsReg;
__ LoadImmediate(kTagsReg, tags);
if (!FLAG_use_slow_path && FLAG_inline_alloc &&
!target::Class::TraceAllocation(cls) &&
target::SizeFitsInSizeTag(instance_size)) {
RELEASE_ASSERT(AllocateObjectInstr::WillAllocateNewOrRemembered(cls));
RELEASE_ASSERT(target::Heap::IsAllocatableInNewSpace(instance_size));
if (is_cls_parameterized) {
if (!IsSameObject(NullObject(),
CastHandle<Object>(allocat_object_parametrized))) {
__ GenerateUnRelocatedPcRelativeTailCall();
unresolved_calls->Add(new UnresolvedPcRelativeCall(
__ CodeSize(), allocat_object_parametrized, /*is_tail_call=*/true));
} else {
__ ldr(R4,
Address(THR,
target::Thread::
allocate_object_parameterized_entry_point_offset()));
__ br(R4);
}
} else {
if (!IsSameObject(NullObject(), CastHandle<Object>(allocate_object))) {
__ GenerateUnRelocatedPcRelativeTailCall();
unresolved_calls->Add(new UnresolvedPcRelativeCall(
__ CodeSize(), allocate_object, /*is_tail_call=*/true));
} else {
__ ldr(
R4,
Address(THR, target::Thread::allocate_object_entry_point_offset()));
__ br(R4);
}
}
} else {
if (!is_cls_parameterized) {
__ LoadObject(AllocateObjectABI::kTypeArgumentsReg, NullObject());
}
__ ldr(R4,
Address(THR,
target::Thread::allocate_object_slow_entry_point_offset()));
__ br(R4);
}
}
// 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() {
__ EnterStubFrame();
// Load the receiver.
__ LoadCompressedSmiFieldFromOffset(
R2, R4, target::ArgumentsDescriptor::size_offset());
__ add(TMP, FP, Operand(R2, LSL, target::kWordSizeLog2 - 1));
__ LoadFromOffset(R6, TMP,
target::frame_layout.param_end_from_fp * target::kWordSize);
// Load the function.
__ LoadCompressedFieldFromOffset(TMP, R6, target::Closure::function_offset());
__ Push(ZR); // Result slot.
__ Push(R6); // Receiver.
__ Push(TMP); // Function
__ Push(R4); // Arguments descriptor.
// Adjust arguments count.
__ LoadCompressedSmiFieldFromOffset(
R3, R4, target::ArgumentsDescriptor::type_args_len_offset());
__ AddImmediate(TMP, R2, 1, kObjectBytes); // Include the type arguments.
__ cmp(R3, Operand(0), kObjectBytes);
// R2 <- (R3 == 0) ? R2 : TMP + 1 (R2 : R2 + 2).
__ csinc(R2, R2, TMP, EQ, kObjectBytes);
// 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.
__ brk(0);
}
// R6: function object.
// R5: 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() {
Register ic_reg = R5;
Register func_reg = R6;
if (FLAG_precompiled_mode) {
__ Breakpoint();
return;
}
if (FLAG_trace_optimized_ic_calls) {
__ EnterStubFrame();
__ Push(R6); // Preserve.
__ Push(R5); // Preserve.
__ Push(ic_reg); // Argument.
__ Push(func_reg); // Argument.
__ CallRuntime(kTraceICCallRuntimeEntry, 2);
__ Drop(2); // Discard argument;
__ Pop(R5); // Restore.
__ Pop(R6); // Restore.
__ LeaveStubFrame();
}
__ LoadFieldFromOffset(R7, func_reg, target::Function::usage_counter_offset(),
kFourBytes);
__ add(R7, R7, Operand(1));
__ StoreFieldToOffset(R7, func_reg, target::Function::usage_counter_offset(),
kFourBytes);
}
// Loads function into 'temp_reg'.
void StubCodeCompiler::GenerateUsageCounterIncrement(Register temp_reg) {
if (FLAG_precompiled_mode) {
__ Breakpoint();
return;
}
if (FLAG_optimization_counter_threshold >= 0) {
Register func_reg = temp_reg;
ASSERT(temp_reg == R6);
__ Comment("Increment function counter");
__ LoadFieldFromOffset(func_reg, IC_DATA_REG,
target::ICData::owner_offset());
__ LoadFieldFromOffset(
R7, func_reg, target::Function::usage_counter_offset(), kFourBytes);
__ AddImmediate(R7, 1);
__ StoreFieldToOffset(R7, func_reg,
target::Function::usage_counter_offset(), kFourBytes);
}
}
// Note: R5 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));
__ BranchIfNotSmi(TMP, not_smi_or_overflow);
switch (kind) {
case Token::kADD: {
__ adds(R0, R1, Operand(R0), kObjectBytes); // Add.
__ b(not_smi_or_overflow, VS); // Branch if overflow.
break;
}
case Token::kLT: {
__ CompareObjectRegisters(R0, R1);
__ LoadObject(R0, CastHandle<Object>(TrueObject()));
__ LoadObject(R1, CastHandle<Object>(FalseObject()));
__ csel(R0, R0, R1, LT);
break;
}
case Token::kEQ: {
__ CompareObjectRegisters(R0, R1);
__ LoadObject(R0, CastHandle<Object>(TrueObject()));
__ LoadObject(R1, CastHandle<Object>(FalseObject()));
__ csel(R0, R0, R1, EQ);
break;
}
default:
UNIMPLEMENTED();
}
// R5: IC data object (preserved).
__ LoadFieldFromOffset(R6, R5, target::ICData::entries_offset());
// R6: ic_data_array with check entries: classes and target functions.
__ AddImmediate(R6, target::Array::data_offset() - kHeapObjectTag);
// R6: 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);
__ LoadCompressedSmiFromOffset(R1, R6, 0);
__ CompareImmediate(R1, imm_smi_cid, kObjectBytes);
__ b(&error, NE);
__ LoadCompressedSmiFromOffset(R1, R6, target::kCompressedWordSize);
__ CompareImmediate(R1, imm_smi_cid, kObjectBytes);
__ b(&ok, EQ);
__ Bind(&error);
__ Stop("Incorrect IC data");
__ Bind(&ok);
#endif
if (FLAG_optimization_counter_threshold >= 0) {
const intptr_t count_offset =
target::ICData::CountIndexFor(num_args) * target::kCompressedWordSize;
// Update counter, ignore overflow.
__ LoadCompressedSmiFromOffset(R1, R6, count_offset);
__ adds(R1, R1, Operand(target::ToRawSmi(1)), kObjectBytes);
__ StoreToOffset(R1, R6, count_offset, kObjectBytes);
}
__ ret();
}
// Saves the offset of the target entry-point (from the Function) into R8.
//
// 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;
__ LoadImmediate(R8, target::Function::entry_point_offset() - kHeapObjectTag);
__ b(&done);
__ BindUncheckedEntryPoint();
__ LoadImmediate(
R8, target::Function::entry_point_offset(CodeEntryKind::kUnchecked) -
kHeapObjectTag);
__ Bind(&done);
}
// Generate inline cache check for 'num_args'.
// R0: receiver (if instance call)
// R5: 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(
intptr_t num_args,
const RuntimeEntry& handle_ic_miss,
Token::Kind kind,
Optimized optimized,
CallType type,
Exactness exactness) {
const bool save_entry_point = kind == Token::kILLEGAL;
if (FLAG_precompiled_mode) {
__ Breakpoint();
return;
}
if (save_entry_point) {
GenerateRecordEntryPoint(assembler);
}
if (optimized == kOptimized) {
GenerateOptimizedUsageCounterIncrement();
} else {
GenerateUsageCounterIncrement(/*scratch=*/R6);
}
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'.
__ LoadFromOffset(R6, R5,
target::ICData::state_bits_offset() - kHeapObjectTag,
kUnsignedFourBytes);
ASSERT(target::ICData::NumArgsTestedShift() == 0); // No shift needed.
__ andi(R6, R6, Immediate(target::ICData::NumArgsTestedMask()));
__ CompareImmediate(R6, 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(R6);
__ LoadFromOffset(R6, R6, target::Isolate::single_step_offset(),
kUnsignedByte);
__ CompareRegisters(R6, ZR);
__ 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");
// R5: IC data object (preserved).
__ LoadFieldFromOffset(R6, R5, target::ICData::entries_offset());
// R6: ic_data_array with check entries: classes and target functions.
__ AddImmediate(R6, target::Array::data_offset() - kHeapObjectTag);
// R6: points directly to the first ic data array element.
if (type == kInstanceCall) {
__ LoadTaggedClassIdMayBeSmi(R3, R0);
__ LoadFieldFromOffset(ARGS_DESC_REG, R5,
target::CallSiteData::arguments_descriptor_offset());
if (num_args == 2) {
__ LoadCompressedSmiFieldFromOffset(
R7, ARGS_DESC_REG, target::ArgumentsDescriptor::count_offset());
__ SmiUntag(R7); // Untag so we can use the LSL 3 addressing mode.
__ sub(R7, R7, Operand(2));
// R1 <- [SP + (R1 << 3)]
__ ldr(R1, Address(SP, R7, UXTX, Address::Scaled));
__ LoadTaggedClassIdMayBeSmi(R1, R1);
}
} else {
__ LoadFieldFromOffset(ARGS_DESC_REG, R5,
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).
__ LoadCompressedSmiFieldFromOffset(
R7, ARGS_DESC_REG, target::ArgumentsDescriptor::count_offset());
__ SmiUntag(R7); // Untag so we can use the LSL 3 addressing mode.
__ sub(R7, R7, Operand(1));
// R0 <- [SP + (R7 << 3)]
__ ldr(R0, Address(SP, R7, UXTX, Address::Scaled));
__ LoadTaggedClassIdMayBeSmi(R3, R0);
if (num_args == 2) {
__ AddImmediate(R1, R7, -1);
// R1 <- [SP + (R1 << 3)]
__ ldr(R1, Address(SP, R1, UXTX, Address::Scaled));
__ LoadTaggedClassIdMayBeSmi(R1, R1);
}
}
// R3: first argument class ID as Smi.
// R1: second argument class ID as Smi.
// R4: args descriptor
// We unroll the generic one that is generated once more than the others.
const bool optimize = kind == Token::kILLEGAL;
// Loop that checks if there is an IC data match.
Label loop, found, miss;
__ Comment("ICData loop");
__ Bind(&loop);
for (int unroll = optimize ? 4 : 2; unroll >= 0; unroll--) {
Label update;
__ LoadCompressedSmiFromOffset(R2, R6, 0);
__ CompareObjectRegisters(R3, R2); // Class id match?
if (num_args == 2) {
__ b(&update, NE); // Continue.
__ LoadCompressedSmiFromOffset(R2, R6, target::kCompressedWordSize);
__ CompareObjectRegisters(R1, R2); // Class id match?
}
__ b(&found, EQ); // Break.
__ Bind(&update);
const intptr_t entry_size = target::ICData::TestEntryLengthFor(
num_args, exactness == kCheckExactness) *
target::kCompressedWordSize;
__ AddImmediate(R6, 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.
__ LoadCompressedSmiFieldFromOffset(
R7, ARGS_DESC_REG, target::ArgumentsDescriptor::count_offset());
__ SmiUntag(R7); // Untag so we can use the LSL 3 addressing mode.
__ sub(R7, R7, Operand(1));
// R7: argument_count - 1 (untagged).
// R7 <- SP + (R7 << 3)
__ add(R7, SP, Operand(R7, UXTX, 3)); // R7 is Untagged.
// R7: address of receiver.
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
// Preserve IC data object and arguments descriptor array and
// setup space on stack for result (target code object).
__ Push(ARGS_DESC_REG); // Preserve arguments descriptor array.
__ Push(R5); // Preserve IC Data.
if (save_entry_point) {
__ SmiTag(R8);
__ Push(R8);
}
// Setup space on stack for the result (target code object).
__ Push(ZR);
// Push call arguments.
for (intptr_t i = 0; i < num_args; i++) {
__ LoadFromOffset(TMP, R7, -i * target::kWordSize);
__ Push(TMP);
}
// Pass IC data object.
__ Push(R5);
__ 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.
__ Pop(FUNCTION_REG); // Pop returned function object into R0.
if (save_entry_point) {
__ Pop(R8);
__ SmiUntag(R8);
}
__ Pop(R5); // Restore IC Data.
__ Pop(ARGS_DESC_REG); // Restore arguments descriptor array.
__ RestoreCodePointer();
__ LeaveStubFrame();
Label call_target_function;
if (!FLAG_lazy_dispatchers) {
GenerateDispatcherCode(assembler, &call_target_function);
} else {
__ b(&call_target_function);
}
__ Bind(&found);
// R6: pointer to an IC data check group.
const intptr_t target_offset =
target::ICData::TargetIndexFor(num_args) * target::kCompressedWordSize;
const intptr_t count_offset =
target::ICData::CountIndexFor(num_args) * target::kCompressedWordSize;
const intptr_t exactness_offset =
target::ICData::ExactnessIndexFor(num_args) * target::kCompressedWordSize;
Label call_target_function_through_unchecked_entry;
if (exactness == kCheckExactness) {
Label exactness_ok;
ASSERT(num_args == 1);
__ LoadCompressedSmi(R1, Address(R6, exactness_offset));
__ CompareImmediate(
R1,
target::ToRawSmi(
StaticTypeExactnessState::HasExactSuperType().Encode()),
kObjectBytes);
__ BranchIf(LESS, &exactness_ok);
__ BranchIf(EQUAL, &call_target_function_through_unchecked_entry);
// Check trivial exactness.
// Note: UntaggedICData::receivers_static_type_ is guaranteed to be not null
// because we only emit calls to this stub when it is not null.
__ LoadCompressed(
R2, FieldAddress(R5, target::ICData::receivers_static_type_offset()));
__ LoadCompressed(R2, FieldAddress(R2, target::Type::arguments_offset()));
// R1 contains an offset to type arguments in words as a smi,
// hence TIMES_4. R0 is guaranteed to be non-smi because it is expected
// to have type arguments.
#if defined(DART_COMPRESSED_POINTERS)
__ sxtw(R1, R1);
#endif
__ LoadIndexedPayload(R3, R0, 0, R1, TIMES_COMPRESSED_HALF_WORD_SIZE,
kObjectBytes);
__ CompareObjectRegisters(R2, R3);
__ BranchIf(EQUAL, &call_target_function_through_unchecked_entry);
// Update exactness state (not-exact anymore).
__ LoadImmediate(
R1, target::ToRawSmi(StaticTypeExactnessState::NotExact().Encode()));
__ StoreToOffset(R1, R6, exactness_offset, kObjectBytes);
__ Bind(&exactness_ok);
}
__ LoadCompressedFromOffset(FUNCTION_REG, R6, target_offset);
if (FLAG_optimization_counter_threshold >= 0) {
__ Comment("Update caller's counter");
__ LoadCompressedSmiFromOffset(R1, R6, count_offset);
// Ignore overflow.
__ add(R1, R1, Operand(target::ToRawSmi(1)), kObjectBytes);
__ StoreToOffset(R1, R6, count_offset, kObjectBytes);
}
__ Comment("Call target");
__ Bind(&call_target_function);
// R0: target function.
__ LoadCompressedFieldFromOffset(CODE_REG, FUNCTION_REG,
target::Function::code_offset());
if (save_entry_point) {
__ add(R2, FUNCTION_REG, Operand(R8));
__ ldr(R2, Address(R2, 0));
} else {
__ LoadFieldFromOffset(R2, FUNCTION_REG,
target::Function::entry_point_offset());
}
__ br(R2);
if (exactness == kCheckExactness) {
__ Bind(&call_target_function_through_unchecked_entry);
if (FLAG_optimization_counter_threshold >= 0) {
__ Comment("Update ICData counter");
__ LoadCompressedSmiFromOffset(R1, R6, count_offset);
// Ignore overflow.
__ add(R1, R1, Operand(target::ToRawSmi(1)), kObjectBytes);
__ StoreToOffset(R1, R6, count_offset, kObjectBytes);
}
__ Comment("Call target (via unchecked entry point)");
__ LoadCompressedFromOffset(FUNCTION_REG, R6, target_offset);
__ LoadCompressedFieldFromOffset(CODE_REG, FUNCTION_REG,
target::Function::code_offset());
__ LoadFieldFromOffset(
R2, FUNCTION_REG,
target::Function::entry_point_offset(CodeEntryKind::kUnchecked));
__ br(R2);
}
#if !defined(PRODUCT)
if (optimized == kUnoptimized) {
__ Bind(&stepping);
__ EnterStubFrame();
if (type == kInstanceCall) {
__ Push(R0); // Preserve receiver.
}
if (save_entry_point) {
__ SmiTag(R8);
__ Push(R8);
}
__ Push(R5); // Preserve IC data.
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ Pop(R5);
if (save_entry_point) {
__ Pop(R8);
__ SmiUntag(R8);
}
if (type == kInstanceCall) {
__ Pop(R0);
}
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
}
#endif
}
// R0: receiver
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateOneArgCheckInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateOneArgCheckInlineCacheWithExactnessCheckStub() {
GenerateNArgsCheckInlineCacheStub(
1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kInstanceCall, kCheckExactness);
}
// R0: receiver
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateTwoArgsCheckInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateSmiAddInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kADD, kUnoptimized,
kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateSmiLessInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kLT, kUnoptimized,
kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateSmiEqualInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kEQ, kUnoptimized,
kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R5: ICData
// R6: Function
// LR: return address
void StubCodeCompiler::GenerateOneArgOptimizedCheckInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL, kOptimized,
kInstanceCall, kIgnoreExactness);
}
// R0: receiver
// R5: ICData
// R6: Function
// LR: return address
void StubCodeCompiler::
GenerateOneArgOptimizedCheckInlineCacheWithExactnessCheckStub() {
GenerateNArgsCheckInlineCacheStub(
1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL, kOptimized,
kInstanceCall, kCheckExactness);
}
// R0: receiver
// R5: ICData
// R6: Function
// LR: return address
void StubCodeCompiler::GenerateTwoArgsOptimizedCheckInlineCacheStub() {
GenerateNArgsCheckInlineCacheStub(
2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
kOptimized, kInstanceCall, kIgnoreExactness);
}
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateZeroArgsUnoptimizedStaticCallStub() {
GenerateRecordEntryPoint(assembler);
GenerateUsageCounterIncrement(/* scratch */ R6);
#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'.
__ LoadFromOffset(R6, R5,
target::ICData::state_bits_offset() - kHeapObjectTag,
kUnsignedFourBytes);
ASSERT(target::ICData::NumArgsTestedShift() == 0); // No shift needed.
__ andi(R6, R6, Immediate(target::ICData::NumArgsTestedMask()));
__ CompareImmediate(R6, 0);
__ b(&ok, EQ);
__ Stop("Incorrect IC data for unoptimized static call");
__ Bind(&ok);
}
#endif // DEBUG
// Check single stepping.
#if !defined(PRODUCT)
Label stepping, done_stepping;
__ LoadIsolate(R6);
__ LoadFromOffset(R6, R6, target::Isolate::single_step_offset(),
kUnsignedByte);
__ CompareImmediate(R6, 0);
__ b(&stepping, NE);
__ Bind(&done_stepping);
#endif
// R5: IC data object (preserved).
__ LoadFieldFromOffset(R6, R5, target::ICData::entries_offset());
// R6: ic_data_array with entries: target functions and count.
__ AddImmediate(R6, target::Array::data_offset() - kHeapObjectTag);
// R6: points directly to the first ic data array element.
const intptr_t target_offset =
target::ICData::TargetIndexFor(0) * target::kCompressedWordSize;
const intptr_t count_offset =
target::ICData::CountIndexFor(0) * target::kCompressedWordSize;
if (FLAG_optimization_counter_threshold >= 0) {
// Increment count for this call, ignore overflow.
__ LoadCompressedSmiFromOffset(R1, R6, count_offset);
__ adds(R1, R1, Operand(target::ToRawSmi(1)), kObjectBytes);
__ StoreToOffset(R1, R6, count_offset, kObjectBytes);
}
// Load arguments descriptor into R4.
__ LoadFieldFromOffset(ARGS_DESC_REG, R5,
target::CallSiteData::arguments_descriptor_offset());
// Get function and call it, if possible.
__ LoadCompressedFromOffset(FUNCTION_REG, R6, target_offset);
__ LoadCompressedFieldFromOffset(CODE_REG, FUNCTION_REG,
target::Function::code_offset());
__ add(R2, FUNCTION_REG, Operand(R8));
__ ldr(R2, Address(R2, 0));
__ br(R2);
#if !defined(PRODUCT)
__ Bind(&stepping);
__ EnterStubFrame();
__ Push(R5); // Preserve IC data.
__ SmiTag(R8);
__ Push(R8);
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ Pop(R8);
__ SmiUntag(R8);
__ Pop(R5);
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
#endif
}
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateOneArgUnoptimizedStaticCallStub() {
GenerateUsageCounterIncrement(/* scratch */ R6);
GenerateNArgsCheckInlineCacheStub(1, kStaticCallMissHandlerOneArgRuntimeEntry,
Token::kILLEGAL, kUnoptimized, kStaticCall,
kIgnoreExactness);
}
// R5: ICData
// LR: return address
void StubCodeCompiler::GenerateTwoArgsUnoptimizedStaticCallStub() {
GenerateUsageCounterIncrement(/* scratch */ R6);
GenerateNArgsCheckInlineCacheStub(
2, kStaticCallMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
kUnoptimized, kStaticCall, kIgnoreExactness);
}
// Stub for compiling a function and jumping to the compiled code.
// ARGS_DESC_REG: Arguments descriptor.
// FUNCTION_REG: Function.
void StubCodeCompiler::GenerateLazyCompileStub() {
// Preserve arg desc.
__ EnterStubFrame();
__ Push(ARGS_DESC_REG); // Save arg. desc.
__ Push(FUNCTION_REG); // Pass function.
__ CallRuntime(kCompileFunctionRuntimeEntry, 1);
__ Pop(FUNCTION_REG); // Restore function.
__ Pop(ARGS_DESC_REG); // Restore arg desc.
__ LeaveStubFrame();
__ LoadCompressedFieldFromOffset(CODE_REG, FUNCTION_REG,
target::Function::code_offset());
__ LoadFieldFromOffset(R2, FUNCTION_REG,
target::Function::entry_point_offset());
__ br(R2);
}
// R5: Contains an ICData.
void StubCodeCompiler::GenerateICCallBreakpointStub() {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(R5); // Preserve IC data.
__ Push(ZR); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG); // Original stub.
__ Pop(R5); // Restore IC data.
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ LoadFieldFromOffset(TMP, CODE_REG, target::Code::entry_point_offset());
__ br(TMP);
#endif // defined(PRODUCT)
}
void StubCodeCompiler::GenerateUnoptStaticCallBreakpointStub() {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
__ EnterStubFrame();
__ Push(R5); // Preserve IC data.
__ Push(ZR); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG); // Original stub.
__ Pop(R5); // Restore IC data.
__ LeaveStubFrame();
__ LoadFieldFromOffset(TMP, CODE_REG, target::Code::entry_point_offset());
__ br(TMP);
#endif // defined(PRODUCT)
}
void StubCodeCompiler::GenerateRuntimeCallBreakpointStub() {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
__ EnterStubFrame();
__ Push(ZR); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG);
__ LeaveStubFrame();
__ LoadFieldFromOffset(R0, CODE_REG, target::Code::entry_point_offset());
__ br(R0);
#endif // defined(PRODUCT)
}
// Called only from unoptimized code. All relevant registers have been saved.
void StubCodeCompiler::GenerateDebugStepCheckStub() {
#if defined(PRODUCT)
__ Stop("No debugging in PRODUCT mode");
#else
// Check single stepping.
Label stepping, done_stepping;
__ LoadIsolate(R1);
__ LoadFromOffset(R1, R1, target::Isolate::single_step_offset(),
kUnsignedByte);
__ 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 (all preserved, mostly from TypeTestABI struct):
// - kSubtypeTestCacheReg: UntaggedSubtypeTestCache
// - kInstanceReg: instance to test against.
// - kDstTypeReg: destination type (for n>=7).
// - kInstantiatorTypeArgumentsReg: instantiator type arguments (for n>=3).
// - kFunctionTypeArgumentsReg: function type arguments (for n>=4).
// - LR: return address.
//
// Outputs (from TypeTestABI struct):
// - kSubtypeTestCacheResultReg: the cached result, or null if not found.
void StubCodeCompiler::GenerateSubtypeNTestCacheStub(Assembler* assembler,
int n) {
ASSERT(n >= 1);
ASSERT(n <= SubtypeTestCache::kMaxInputs);
// If we need the parent function type arguments for a closure, we also need
// the delayed type arguments, so this case will never happen.
ASSERT(n != 5);
// We could initialize kSubtypeTestCacheResultReg with null and use that as
// the null register up until exit, which means we'd just need to return
// without setting it in the not_found case.
//
// However, that would mean the expense of keeping another register live
// across the loop to hold the cache entry address, and the not_found case
// means we're going to runtime, so optimize for the found case instead.
//
// Thus, we use it to store the current cache entry, since it's distinct from
// all the preserved input registers and the scratch register, and the last
// use of the current cache entry is to set kSubtypeTestCacheResultReg.
const Register kCacheArrayReg = TypeTestABI::kSubtypeTestCacheResultReg;
Label not_found;
GenerateSubtypeTestCacheSearch(
assembler, n, NULL_REG, kCacheArrayReg,
STCInternalRegs::kInstanceCidOrSignatureReg,
STCInternalRegs::kInstanceInstantiatorTypeArgumentsReg,
STCInternalRegs::kInstanceParentFunctionTypeArgumentsReg,
STCInternalRegs::kInstanceDelayedFunctionTypeArgumentsReg,
STCInternalRegs::kCacheEntriesEndReg,
STCInternalRegs::kCacheContentsSizeReg,
STCInternalRegs::kProbeDistanceReg,
[&](Assembler* assembler, int n) {
__ LoadCompressed(
TypeTestABI::kSubtypeTestCacheResultReg,
Address(kCacheArrayReg, target::kCompressedWordSize *
target::SubtypeTestCache::kTestResult));
__ Ret();
},
[&](Assembler* assembler, int n) {
__ MoveRegister(TypeTestABI::kSubtypeTestCacheResultReg, NULL_REG);
__ Ret();
});
}
void StubCodeCompiler::GenerateGetCStackPointerStub() {
__ mov(R0, CSP);
__ 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() {
ASSERT(kExceptionObjectReg == R0);
ASSERT(kStackTraceObjectReg == R1);
__ set_lr_state(compiler::LRState::Clobbered());
__ mov(CALLEE_SAVED_TEMP, R0); // Program counter.
__ mov(SP, R1); // Stack pointer.
__ mov(FP, R2); // Frame_pointer.
__ mov(THR, R3);
__ SetupCSPFromThread(THR);
#if defined(DART_TARGET_OS_FUCHSIA)
// We need to restore the shadow call stack pointer like longjmp would,
// effectively popping all the return addresses between the Dart exit frame
// and Exceptions::JumpToFrame, otherwise the shadow call stack might
// eventually overflow.
__ ldr(R18, Address(THR, target::Thread::saved_shadow_call_stack_offset()));
#elif 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 - this is needed
// because normally runtime calls transition back to generated via destructor
// of TransitionGeneratedToVM/Native that is part of runtime boilerplate
// code (see DEFINE_RUNTIME_ENTRY_IMPL in runtime_entry.h). Ffi calls don't
// have this boilerplate, don't have this stack resource, have to transition
// explicitly.
__ 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, /*leave_safepoint=*/true,
/*ignore_unwind_in_progress=*/true);
__ Bind(&exit_through_non_ffi);
// Refresh pinned registers (write barrier mask, null, dispatch table, etc).
__ RestorePinnedRegisters();
// Set the tag.
__ LoadImmediate(R2, VMTag::kDartTagId);
__ StoreToOffset(R2, THR, target::Thread::vm_tag_offset());
// Clear top exit frame.
__ StoreToOffset(ZR, THR, target::Thread::top_exit_frame_info_offset());
// Restore the pool pointer.
__ RestoreCodePointer();
if (FLAG_precompiled_mode) {
__ SetupGlobalPoolAndDispatchTable();
} else {
__ LoadPoolPointer();
}
__ ret(CALLEE_SAVED_TEMP); // 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() {
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());
__ ret(); // 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() {
// Push zap value instead of CODE_REG.
__ LoadImmediate(TMP, kZapCodeReg);
__ Push(TMP);
// 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();
__ brk(0);
}
// Calls to the runtime to optimize the given function.
// R6: function to be re-optimized.
// ARGS_DESC_REG: argument descriptor (preserved).
void StubCodeCompiler::GenerateOptimizeFunctionStub() {
__ LoadFromOffset(CODE_REG, THR, target::Thread::optimize_stub_offset());
__ EnterStubFrame();
__ Push(ARGS_DESC_REG);
// Setup space on stack for the return value.
__ Push(ZR);
__ Push(R6);
__ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry, 1);
__ Pop(R0); // Discard argument.
__ Pop(FUNCTION_REG); // Get Function object
__ Pop(ARGS_DESC_REG); // Restore argument descriptor.
__ LoadCompressedFieldFromOffset(CODE_REG, FUNCTION_REG,
target::Function::code_offset());
__ LoadFieldFromOffset(R1, FUNCTION_REG,
target::Function::entry_point_offset());
__ LeaveStubFrame();
__ br(R1);
__ brk(0);
}
// Does identical check (object references are equal or not equal) with special
// checks for boxed numbers and returns with ZF set iff left and right are
// identical.
static void GenerateIdenticalWithNumberCheckStub(Assembler* assembler,
const Register left,
const Register right) {
Label reference_compare, check_mint;
// If any of the arguments is Smi do reference compare.
// Note: A Mint cannot contain a value that would fit in Smi.
__ BranchIfSmi(left, &reference_compare);
__ BranchIfSmi(right, &reference_compare);
// Value compare for two doubles.
__ CompareClassId(left, kDoubleCid);
__ b(&check_mint, NE);
__ CompareClassId(right, kDoubleCid);
__ b(&reference_compare, NE); // Do not branch directly to ret! See below.
// Double values bitwise compare.
__ LoadFieldFromOffset(left, left, target::Double::value_offset());
__ LoadFieldFromOffset(right, right, target::Double::value_offset());
__ CompareRegisters(left, right);
__ ret();
__ Bind(&check_mint);
__ CompareClassId(left, kMintCid);
__ b(&reference_compare, NE);
__ CompareClassId(right, kMintCid);
__ b(&reference_compare, NE); // Do not branch directly to ret! See below.
__ LoadFieldFromOffset(left, left, target::Mint::value_offset());
__ LoadFieldFromOffset(right, right, target::Mint::value_offset());
__ CompareRegisters(left, right);
__ ret();
__ Bind(&reference_compare);
__ CompareObjectRegisters(left, right);
// None of the branches above go directly here to avoid generating a
// conditional branch to a ret instruction.
// This is an attempt to workaround a possible CPU on Exynos 2100 SoC.
// See https://github.com/flutter/flutter/issues/88261
__ ret();
}
// Called only from unoptimized code. All relevant registers have been saved.
// LR: return address.
// SP + 4: left operand.
// SP + 0: right operand.
// Return Zero condition flag set if equal.
void StubCodeCompiler::GenerateUnoptimizedIdenticalWithNumberCheckStub() {
#if !defined(PRODUCT)
// Check single stepping.
Label stepping, done_stepping;
__ LoadIsolate(R1);
__ LoadFromOffset(R1, R1, target::Isolate::single_step_offset(),
kUnsignedByte);
__ CompareImmediate(R1, 0);
__ b(&stepping, NE);
__ Bind(&done_stepping);
#endif
const Register left = R1;
const Register right = R0;
__ LoadFromOffset(left, SP, 1 * target::kWordSize);
__ LoadFromOffset(right, SP, 0 * target::kWordSize);
GenerateIdenticalWithNumberCheckStub(assembler, left, right);
#if !defined(PRODUCT)
__ Bind(&stepping);
__ EnterStubFrame();
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
#endif
}
// Called from optimized code only.
// LR: return address.
// SP + 4: left operand.
// SP + 0: right operand.
// Return Zero condition flag set if equal.
void StubCodeCompiler::GenerateOptimizedIdenticalWithNumberCheckStub() {
const Register left = R1;
const Register right = R0;
__ LoadFromOffset(left, SP, 1 * target::kWordSize);
__ LoadFromOffset(right, SP, 0 * target::kWordSize);
GenerateIdenticalWithNumberCheckStub(assembler, left, right);
}
// Called from megamorphic call sites.
// R0: receiver (passed to target)
// IC_DATA_REG: MegamorphicCache (preserved)
// Passed to target:
// FUNCTION_REG: target function
// CODE_REG: target Code
// ARGS_DESC_REG: arguments descriptor
void StubCodeCompiler::GenerateMegamorphicCallStub() {
// Jump if receiver is a smi.
Label smi_case;
__ BranchIfSmi(R0, &smi_case);
// Loads the cid of the object.
__ LoadClassId(R8, R0);
Label cid_loaded;
__ Bind(&cid_loaded);
__ ldr(R2,
FieldAddress(IC_DATA_REG, target::MegamorphicCache::buckets_offset()));
__ ldr(R1,
FieldAddress(IC_DATA_REG, target::MegamorphicCache::mask_offset()));
// R2: cache buckets array.
// R1: mask as a smi.
// Make the cid into a smi.
__ SmiTag(R8);
// R8: class ID of the receiver (smi).
// Compute the table index.
ASSERT(target::MegamorphicCache::kSpreadFactor == 7);
// Use lsl and sub to multiply with 7 == 8 - 1.
__ LslImmediate(R3, R8, 3);
__ sub(R3, R3, Operand(R8));
// R3: probe.
Label loop;
__ Bind(&loop);
__ and_(R3, R3, Operand(R1));
const intptr_t base = target::Array::data_offset();
// R3 is smi tagged, but table entries are 16 bytes, so LSL 3.
__ add(TMP, R2, Operand(R3, LSL, kCompressedWordSizeLog2));
__ LoadCompressedSmiFieldFromOffset(R6, TMP, base);
Label probe_failed;
__ CompareObjectRegisters(R6, R8);
__ b(&probe_failed, NE);
Label load_target;
__ Bind(&load_target);
// Call the target found in the cache. For a class id match, this is a
// proper target for the given name and arguments descriptor. If the
// illegal class id was found, the target is a cache miss handler that can
// be invoked as a normal Dart function.
__ LoadCompressed(FUNCTION_REG,
FieldAddress(TMP, base + target::kCompressedWordSize));
__ ldr(R1,
FieldAddress(FUNCTION_REG, target::Function::entry_point_offset()));
__ ldr(ARGS_DESC_REG,
FieldAddress(IC_DATA_REG,
target::CallSiteData::arguments_descriptor_offset()));
if (!FLAG_precompiled_mode) {
__ LoadCompressed(
CODE_REG, FieldAddress(FUNCTION_REG, target::Function::code_offset()));
}
__ br(R1);
// Probe failed, check if it is a miss.
__ Bind(&probe_failed);
ASSERT(kIllegalCid == 0);
__ tst(R6, Operand(R6), kObjectBytes);
Label miss;
__ b(&miss, EQ); // branch if miss.
// Try next extry in the table.
__ AddImmediate(R3, target::ToRawSmi(1));
__ b(&loop);
// Load cid for the Smi case.
__ Bind(&smi_case);
__ LoadImmediate(R8, kSmiCid);
__ b(&cid_loaded);
__ Bind(&miss);
GenerateSwitchableCallMissStub();
}
// Input:
// R0 - receiver
// IC_DATA_REG - icdata
void StubCodeCompiler::GenerateICCallThroughCodeStub() {
Label loop, found, miss;
__ ldr(R8, FieldAddress(IC_DATA_REG, target::ICData::entries_offset()));
__ ldr(ARGS_DESC_REG,
FieldAddress(IC_DATA_REG,
target::CallSiteData::arguments_descriptor_offset()));
__ AddImmediate(R8, target::Array::data_offset() - kHeapObjectTag);
// R8: first IC entry
__ LoadTaggedClassIdMayBeSmi(R1, R0);
// R1: receiver cid as Smi
__ Bind(&loop);
__ LoadCompressedSmi(R2, Address(R8, 0));
__ cmp(R1, Operand(R2), kObjectBytes);
__ b(&found, EQ);
__ CompareImmediate(R2, target::ToRawSmi(kIllegalCid), kObjectBytes);
__ b(&miss, EQ);
const intptr_t entry_length =
target::ICData::TestEntryLengthFor(1, /*tracking_exactness=*/false) *
target::kCompressedWordSize;
__ AddImmediate(R8, entry_length); // Next entry.
__ b(&loop);
__ Bind(&found);
if (FLAG_precompiled_mode) {
const intptr_t entry_offset =
target::ICData::EntryPointIndexFor(1) * target::kCompressedWordSize;
__ LoadCompressed(R1, Address(R8, entry_offset));
__ ldr(R1, FieldAddress(R1, target::Function::entry_point_offset()));
} else {
const intptr_t code_offset =
target::ICData::CodeIndexFor(1) * target::kCompressedWordSize;
__ LoadCompressed(CODE_REG, Address(R8, code_offset));
__ ldr(R1, FieldAddress(CODE_REG, target::Code::entry_point_offset()));
}
__ br(R1);
__ Bind(&miss);
__ ldr(R1, Address(THR, target::Thread::switchable_call_miss_entry_offset()));
__ br(R1);
}
// Implement the monomorphic entry check for call-sites where the receiver
// might be a Smi.
//
// R0: receiver
// R5: MonomorphicSmiableCall object
//
// R1: clobbered
void StubCodeCompiler::GenerateMonomorphicSmiableCheckStub() {
Label miss;
__ LoadClassIdMayBeSmi(IP0, R0);
// Note: this stub is only used in AOT mode, hence the direct (bare) call.
__ LoadField(
IP1,
FieldAddress(R5, target::MonomorphicSmiableCall::expected_cid_offset()));
__ LoadField(
R1,
FieldAddress(R5, target::MonomorphicSmiableCall::entrypoint_offset()));
__ cmp(IP0, Operand(IP1));
__ b(&miss, NE);
__ br(R1);
__ Bind(&miss);
__ ldr(IP0,
Address(THR, target::Thread::switchable_call_miss_entry_offset()));
__ br(IP0);
}
// Called from switchable IC calls.
// R0: receiver
void StubCodeCompiler::GenerateSwitchableCallMissStub() {
__ ldr(CODE_REG,
Address(THR, target::Thread::switchable_call_miss_stub_offset()));
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(ZR); // Result slot.
__ Push(ZR); // Arg0: stub out.
__ Push(R0); // Arg1: Receiver
__ CallRuntime(kSwitchableCallMissRuntimeEntry, 2);
__ Drop(1);
__ Pop(CODE_REG); // result = stub
__ Pop(R5); // result = IC
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ ldr(R1, FieldAddress(CODE_REG, target::Code::entry_point_offset(
CodeEntryKind::kNormal)));
__ br(R1);
}
// Called from switchable IC calls.
// R0: receiver
// R5: SingleTargetCache
// Passed to target:
// CODE_REG: target Code object
void StubCodeCompiler::GenerateSingleTargetCallStub() {
Label miss;
__ LoadClassIdMayBeSmi(R1, R0);
__ ldr(R2, FieldAddress(R5, target::SingleTargetCache::lower_limit_offset()),
kUnsignedTwoBytes);
__ ldr(R3, FieldAddress(R5, target::SingleTargetCache::upper_limit_offset()),
kUnsignedTwoBytes);
__ cmp(R1, Operand(R2));
__ b(&miss, LT);
__ cmp(R1, Operand(R3));
__ b(&miss, GT);
__ ldr(R1, FieldAddress(R5, target::SingleTargetCache::entry_point_offset()));
__ ldr(CODE_REG,
FieldAddress(R5, target::SingleTargetCache::target_offset()));
__ br(R1);
__ Bind(&miss);
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(ZR); // Result slot.
__ Push(ZR); // Arg0: Stub out.
__ Push(R0); // Arg1: Receiver
__ CallRuntime(kSwitchableCallMissRuntimeEntry, 2);
__ Drop(1);
__ Pop(CODE_REG); // result = stub
__ Pop(R5); // result = IC
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ ldr(R1, FieldAddress(CODE_REG, target::Code::entry_point_offset(
CodeEntryKind::kMonomorphic)));
__ br(R1);
}
static int GetScaleFactor(intptr_t size) {
switch (size) {
case 1:
return 0;
case 2:
return 1;
case 4:
return 2;
case 8:
return 3;
case 16:
return 4;
}
UNREACHABLE();
return -1;
}
void StubCodeCompiler::GenerateAllocateTypedDataArrayStub(intptr_t cid) {
const intptr_t element_size = TypedDataElementSizeInBytes(cid);
const intptr_t max_len = TypedDataMaxNewSpaceElements(cid);
const intptr_t scale_shift = GetScaleFactor(element_size);
COMPILE_ASSERT(AllocateTypedDataArrayABI::kLengthReg == R4);
COMPILE_ASSERT(AllocateTypedDataArrayABI::kResultReg == R0);
if (!FLAG_use_slow_path && FLAG_inline_alloc) {
Label call_runtime;
NOT_IN_PRODUCT(__ MaybeTraceAllocation(cid, &call_runtime, R2));
__ mov(R2, AllocateTypedDataArrayABI::kLengthReg);
/* Check that length is a positive Smi. */
/* R2: requested array length argument. */
__ BranchIfNotSmi(R2, &call_runtime);
__ SmiUntag(R2);
/* Check for length >= 0 && length <= max_len. */
/* R2: untagged array length. */
__ CompareImmediate(R2, max_len, kObjectBytes);
__ b(&call_runtime, HI);
__ LslImmediate(R2, R2, scale_shift);
const intptr_t fixed_size_plus_alignment_padding =
target::TypedData::HeaderSize() +
target::ObjectAlignment::kObjectAlignment - 1;
__ AddImmediate(R2, fixed_size_plus_alignment_padding);
__ andi(R2, R2,
Immediate(~(target::ObjectAlignment::kObjectAlignment - 1)));
__ ldr(R0, Address(THR, target::Thread::top_offset()));
/* R2: allocation size. */
__ adds(R1, R0, Operand(R2));
__ b(&call_runtime, CS); /* Fail on unsigned overflow. */
/* Check if the allocation fits into the remaining space. */
/* R0: potential new object start. */
/* R1: potential next object start. */
/* R2: allocation size. */
__ ldr(R6, Address(THR, target::Thread::end_offset()));
__ cmp(R1, Operand(R6));
__ b(&call_runtime, CS);
__ CheckAllocationCanary(R0);
/* Successfully allocated the object(s), now update top to point to */
/* next object start and initialize the object. */
__ str(R1, Address(THR, target::Thread::top_offset()));
__ AddImmediate(R0, kHeapObjectTag);
/* Initialize the tags. */
/* R0: new object start as a tagged pointer. */
/* R1: new object end address. */
/* R2: allocation size. */
{
__ CompareImmediate(R2, target::UntaggedObject::kSizeTagMaxSizeTag);
__ LslImmediate(R2, R2,
target::UntaggedObject::kTagBitsSizeTagPos -
target::ObjectAlignment::kObjectAlignmentLog2);
__ csel(R2, ZR, R2, HI);
/* Get the class index and insert it into the tags. */
uword tags =
target::MakeTagWordForNewSpaceObject(cid, /*instance_size=*/0);
__ LoadImmediate(TMP, tags);
__ orr(R2, R2, Operand(TMP));
__ str(R2, FieldAddress(R0, target::Object::tags_offset())); /* Tags. */
}
/* Set the length field. */
/* R0: new object start as a tagged pointer. */
/* R1: new object end address. */
__ mov(R2, AllocateTypedDataArrayABI::kLengthReg); /* Array length. */
__ StoreCompressedIntoObjectNoBarrier(
R0, FieldAddress(R0, target::TypedDataBase::length_offset()), R2);
/* Initialize all array elements to 0. */
/* R0: new object start as a tagged pointer. */
/* R1: new object end address. */
/* R2: iterator which initially points to the start of the variable */
/* data area to be initialized. */
__ AddImmediate(R2, R0, target::TypedData::HeaderSize() - 1);
__ StoreInternalPointer(
R0, FieldAddress(R0, target::PointerBase::data_offset()), R2);
Label loop;
__ Bind(&loop);
ASSERT(target::kObjectAlignment == 2 * target::kWordSize);
__ stp(ZR, ZR, Address(R2, 2 * target::kWordSize, Address::PairPostIndex));
__ cmp(R2, Operand(R1));
__ b(&loop, UNSIGNED_LESS);
__ WriteAllocationCanary(R1); // Fix overshoot.
__ Ret();
__ Bind(&call_runtime);
}
__ EnterStubFrame();
__ Push(ZR); // Result slot.
__ PushImmediate(target::ToRawSmi(cid)); // Cid
__ Push(AllocateTypedDataArrayABI::kLengthReg); // Array length
__ CallRuntime(kAllocateTypedDataRuntimeEntry, 2);
__ Drop(2); // Drop arguments.
__ Pop(AllocateTypedDataArrayABI::kResultReg);
__ LeaveStubFrame();
__ Ret();
}
} // namespace compiler
} // namespace dart
#endif // defined(TARGET_ARCH_ARM64)