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sdk/runtime/vm/stub_code_arm64.cc
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Vyacheslav Egorov f496e538f4 [vm] Decouple assemblers from runtime. 
This is the next step towards preventing compiler from directly peeking
into runtime and instead interact with runtime through a well defined
surface. The goal of the refactoring to locate all places where compiler
accesses some runtime information and partion those accesses into two
categories:

- creating objects in the host runtime (e.g. allocating strings, numbers, etc)
during compilation;
- accessing properties of the target runtime (e.g. offsets of fields) to
embed those into the generated code;

This change introduces dart::compiler and dart::compiler::target namespaces.

All code in the compiler will gradually be moved into dart::compiler namespace.
One of the motivations for this change is to be able to prevent access to
globally defined host constants like kWordSize by shadowing them in the
dart::compiler namespace.

The nested namespace dart::compiler::target hosts all information about
target runtime that compiler could access, e.g. compiler::target::kWordSize
defines word size of the target which will eventually be made different
from the host kWordSize (defined by dart::kWordSize).

The API for compiler to runtime interaction is placed into compiler_api.h.

Note that we still permit runtime to access compiler internals directly -
this is not going to be decoupled as part of this work.

Issue https://github.com/dart-lang/sdk/issues/31709

Change-Id: If4396d295879391becfa6c38d4802bbff81f5b20
Reviewed-on: https://dart-review.googlesource.com/c/90242
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2019-01-25 16:45:13 +00:00

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// Copyright (c) 2014, 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"
#if defined(TARGET_ARCH_ARM64) && !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/compiler/assembler/assembler.h"
#include "vm/compiler/backend/flow_graph_compiler.h"
#include "vm/compiler/jit/compiler.h"
#include "vm/dart_entry.h"
#include "vm/heap/heap.h"
#include "vm/instructions.h"
#include "vm/object_store.h"
#include "vm/runtime_entry.h"
#include "vm/stack_frame.h"
#include "vm/stub_code.h"
#include "vm/tags.h"
#include "vm/type_testing_stubs.h"
#define __ assembler->
namespace dart {
DEFINE_FLAG(bool, inline_alloc, true, "Inline allocation of objects.");
DEFINE_FLAG(bool,
use_slow_path,
false,
"Set to true for debugging & verifying the slow paths.");
DECLARE_FLAG(bool, enable_interpreter);
DECLARE_FLAG(bool, precompiled_mode);
// 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 StubCode::GenerateCallToRuntimeStub(Assembler* assembler) {
const intptr_t thread_offset = NativeArguments::thread_offset();
const intptr_t argc_tag_offset = NativeArguments::argc_tag_offset();
const intptr_t argv_offset = NativeArguments::argv_offset();
const intptr_t retval_offset = NativeArguments::retval_offset();
__ Comment("CallToRuntimeStub");
__ ldr(CODE_REG, Address(THR, 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, Thread::top_exit_frame_info_offset());
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R8, THR, Thread::vm_tag_offset());
__ CompareImmediate(R8, VMTag::kDartCompiledTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Mark that the thread is executing VM code.
__ StoreToOffset(R5, THR, Thread::vm_tag_offset());
// Reserve space for arguments and align frame before entering C++ world.
// NativeArguments are passed in registers.
__ Comment("align stack");
// Reserve space for arguments.
ASSERT(sizeof(NativeArguments) == 4 * kWordSize);
__ ReserveAlignedFrameSpace(sizeof(NativeArguments));
// Pass NativeArguments structure by value and call runtime.
// Registers R0, R1, R2, and R3 are used.
ASSERT(thread_offset == 0 * kWordSize);
// Set thread in NativeArgs.
__ mov(R0, THR);
// There are no runtime calls to closures, so we do not need to set the tag
// bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
ASSERT(argc_tag_offset == 1 * kWordSize);
__ mov(R1, R4); // Set argc in NativeArguments.
ASSERT(argv_offset == 2 * kWordSize);
__ add(R2, ZR, Operand(R4, LSL, 3));
__ add(R2, FP, Operand(R2)); // Compute argv.
// Set argv in NativeArguments.
__ AddImmediate(R2, kParamEndSlotFromFp * kWordSize);
ASSERT(retval_offset == 3 * kWordSize);
__ AddImmediate(R3, R2, 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 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 write barrier mask.
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Retval is next to 1st argument.
// Mark that the thread is executing Dart code.
__ LoadImmediate(R2, VMTag::kDartCompiledTagId);
__ StoreToOffset(R2, THR, Thread::vm_tag_offset());
// Reset exit frame information in Isolate structure.
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
// Restore the global object pool after returning from runtime (old space is
// moving, so the GOP could have been relocated).
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ ldr(PP, Address(THR, Thread::global_object_pool_offset()));
__ sub(PP, PP, Operand(kHeapObjectTag)); // Pool in PP is untagged!
}
__ 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 StubCode::GenerateSharedStub(Assembler* assembler,
bool save_fpu_registers,
const RuntimeEntry* target,
intptr_t self_code_stub_offset_from_thread,
bool allow_return) {
// We want the saved registers to appear like part of the caller's frame, so
// we push them before calling EnterStubFrame.
RegisterSet all_registers;
all_registers.AddAllNonReservedRegisters(save_fpu_registers);
// To make the stack map calculation architecture independent we do the same
// as on intel.
__ Push(LR);
__ PushRegisters(all_registers);
__ ldr(CODE_REG, Address(THR, self_code_stub_offset_from_thread));
__ EnterStubFrame();
__ CallRuntime(*target, /*argument_count=*/0);
if (!allow_return) {
__ Breakpoint();
return;
}
__ LeaveStubFrame();
__ PopRegisters(all_registers);
__ Pop(LR);
__ ret(LR);
}
// R1: The extracted method.
// R4: The type_arguments_field_offset (or 0)
void StubCode::GenerateBuildMethodExtractorStub(Assembler* assembler) {
Thread* thread = Thread::Current();
Zone* Z = thread->zone();
ObjectStore* object_store = thread->isolate()->object_store();
const auto& closure_class =
Class::ZoneHandle(Z, object_store->closure_class());
const auto& closure_allocation_stub =
Code::ZoneHandle(Z, StubCode::GetAllocationStubForClass(closure_class));
const intptr_t kReceiverOffset =
compiler::target::frame_layout.param_end_from_fp + 1;
const auto& context_allocation_stub = StubCode::AllocateContext();
__ EnterStubFrame();
// Build type_arguments vector (or null)
Label no_type_args;
__ ldr(R3, Address(THR, Thread::object_null_offset()), kDoubleWord);
__ cmp(R4, Operand(0));
__ b(&no_type_args, EQ);
__ ldr(R0, Address(FP, kReceiverOffset * kWordSize));
__ ldr(R3, Address(R0, R4));
__ Bind(&no_type_args);
// Push type arguments & extracted method.
__ PushPair(R3, R1);
// Allocate context.
{
Label done, slow_path;
__ TryAllocateArray(kContextCid, Context::InstanceSize(1), &slow_path,
R0, // instance
R1, // end address
R2, R3);
__ ldr(R1, Address(THR, Thread::object_null_offset()));
__ str(R1, FieldAddress(R0, Context::parent_offset()));
__ LoadImmediate(R1, 1);
__ str(R1, FieldAddress(R0, Context::num_variables_offset()));
__ b(&done);
__ Bind(&slow_path);
__ LoadImmediate(/*num_vars=*/R1, 1);
__ LoadObject(CODE_REG, context_allocation_stub);
__ ldr(R0, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ blr(R0);
__ Bind(&done);
}
// Store receiver in context
__ ldr(R1, Address(FP, kWordSize * kReceiverOffset));
__ StoreIntoObject(R0, FieldAddress(R0, Context::variable_offset(0)), R1);
// Push context.
__ Push(R0);
// Allocate closure.
__ LoadObject(CODE_REG, closure_allocation_stub);
__ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset(
Code::EntryKind::kUnchecked)));
__ blr(R1);
// Populate closure object.
__ Pop(R1); // Pop context.
__ StoreIntoObject(R0, FieldAddress(R0, Closure::context_offset()), R1);
__ PopPair(R3, R1); // Pop type arguments & extracted method.
__ StoreIntoObjectNoBarrier(R0, FieldAddress(R0, Closure::function_offset()),
R1);
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, Closure::instantiator_type_arguments_offset()), R3);
__ LoadObject(R1, Object::empty_type_arguments());
__ StoreIntoObjectNoBarrier(
R0, FieldAddress(R0, Closure::delayed_type_arguments_offset()), R1);
__ LeaveStubFrame();
__ Ret();
}
void StubCode::GenerateNullErrorSharedWithoutFPURegsStub(Assembler* assembler) {
GenerateSharedStub(assembler, /*save_fpu_registers=*/false,
&kNullErrorRuntimeEntry,
Thread::null_error_shared_without_fpu_regs_stub_offset(),
/*allow_return=*/false);
}
void StubCode::GenerateNullErrorSharedWithFPURegsStub(Assembler* assembler) {
GenerateSharedStub(assembler, /*save_fpu_registers=*/true,
&kNullErrorRuntimeEntry,
Thread::null_error_shared_with_fpu_regs_stub_offset(),
/*allow_return=*/false);
}
void StubCode::GenerateStackOverflowSharedWithoutFPURegsStub(
Assembler* assembler) {
GenerateSharedStub(
assembler, /*save_fpu_registers=*/false, &kStackOverflowRuntimeEntry,
Thread::stack_overflow_shared_without_fpu_regs_stub_offset(),
/*allow_return=*/true);
}
void StubCode::GenerateStackOverflowSharedWithFPURegsStub(
Assembler* assembler) {
GenerateSharedStub(assembler, /*save_fpu_registers=*/true,
&kStackOverflowRuntimeEntry,
Thread::stack_overflow_shared_with_fpu_regs_stub_offset(),
/*allow_return=*/true);
}
void StubCode::GeneratePrintStopMessageStub(Assembler* assembler) {
__ Stop("GeneratePrintStopMessageStub");
}
// 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 = NativeArguments::thread_offset();
const intptr_t argc_tag_offset = NativeArguments::argc_tag_offset();
const intptr_t argv_offset = NativeArguments::argv_offset();
const intptr_t retval_offset = NativeArguments::retval_offset();
__ EnterStubFrame();
// Save exit frame information to enable stack walking as we are about
// to transition to native code.
__ StoreToOffset(FP, THR, Thread::top_exit_frame_info_offset());
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R6, THR, Thread::vm_tag_offset());
__ CompareImmediate(R6, VMTag::kDartCompiledTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Mark that the thread is executing native code.
__ StoreToOffset(R5, THR, Thread::vm_tag_offset());
// Reserve space for the native arguments structure passed on the stack (the
// outgoing pointer parameter to the native arguments structure is passed in
// R0) and align frame before entering the C++ world.
__ ReserveAlignedFrameSpace(sizeof(NativeArguments));
// Initialize NativeArguments structure and call native function.
// Registers R0, R1, R2, and R3 are used.
ASSERT(thread_offset == 0 * kWordSize);
// Set thread in NativeArgs.
__ mov(R0, THR);
// There are no native calls to closures, so we do not need to set the tag
// bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
ASSERT(argc_tag_offset == 1 * kWordSize);
// Set argc in NativeArguments: R1 already contains argc.
ASSERT(argv_offset == 2 * kWordSize);
// Set argv in NativeArguments: R2 already contains argv.
// Set retval in NativeArgs.
ASSERT(retval_offset == 3 * kWordSize);
__ AddImmediate(R3, FP, 2 * 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 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.
__ ldr(LR, wrapper);
__ blr(LR);
// Restore SP and CSP.
__ mov(SP, CSP);
__ mov(CSP, R25);
// Refresh write barrier mask.
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Mark that the thread is executing Dart code.
__ LoadImmediate(R2, VMTag::kDartCompiledTagId);
__ StoreToOffset(R2, THR, Thread::vm_tag_offset());
// Reset exit frame information in Isolate structure.
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
__ LeaveStubFrame();
__ ret();
}
void StubCode::GenerateCallNoScopeNativeStub(Assembler* assembler) {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR, Thread::no_scope_native_wrapper_entry_point_offset()));
}
void StubCode::GenerateCallAutoScopeNativeStub(Assembler* assembler) {
GenerateCallNativeWithWrapperStub(
assembler,
Address(THR, 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 StubCode::GenerateCallBootstrapNativeStub(Assembler* assembler) {
const intptr_t thread_offset = NativeArguments::thread_offset();
const intptr_t argc_tag_offset = NativeArguments::argc_tag_offset();
const intptr_t argv_offset = NativeArguments::argv_offset();
const intptr_t retval_offset = NativeArguments::retval_offset();
__ EnterStubFrame();
// Save exit frame information to enable stack walking as we are about
// to transition to native code.
__ StoreToOffset(FP, THR, Thread::top_exit_frame_info_offset());
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R6, THR, Thread::vm_tag_offset());
__ CompareImmediate(R6, VMTag::kDartCompiledTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Mark that the thread is executing native code.
__ StoreToOffset(R5, THR, Thread::vm_tag_offset());
// Reserve space for the native arguments structure passed on the stack (the
// outgoing pointer parameter to the native arguments structure is passed in
// R0) and align frame before entering the C++ world.
__ ReserveAlignedFrameSpace(sizeof(NativeArguments));
// Initialize NativeArguments structure and call native function.
// Registers R0, R1, R2, and R3 are used.
ASSERT(thread_offset == 0 * kWordSize);
// Set thread in NativeArgs.
__ mov(R0, THR);
// There are no native calls to closures, so we do not need to set the tag
// bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
ASSERT(argc_tag_offset == 1 * kWordSize);
// Set argc in NativeArguments: R1 already contains argc.
ASSERT(argv_offset == 2 * kWordSize);
// Set argv in NativeArguments: R2 already contains argv.
// Set retval in NativeArgs.
ASSERT(retval_offset == 3 * kWordSize);
__ AddImmediate(R3, FP, 2 * 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 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);
// Call native function or redirection via simulator.
__ blr(R5);
// Restore SP and CSP.
__ mov(SP, CSP);
__ mov(CSP, R25);
// Refresh write barrier mask.
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Mark that the thread is executing Dart code.
__ LoadImmediate(R2, VMTag::kDartCompiledTagId);
__ StoreToOffset(R2, THR, Thread::vm_tag_offset());
// Reset exit frame information in Isolate structure.
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
__ LeaveStubFrame();
__ ret();
}
// Input parameters:
// R4: arguments descriptor array.
void StubCode::GenerateCallStaticFunctionStub(Assembler* assembler) {
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame();
// Setup space on stack for return value and preserve arguments descriptor.
__ Push(R4);
__ Push(ZR);
__ CallRuntime(kPatchStaticCallRuntimeEntry, 0);
// Get Code object result and restore arguments descriptor array.
__ Pop(CODE_REG);
__ Pop(R4);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(R0, CODE_REG, 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).
// R4: arguments descriptor array.
void StubCode::GenerateFixCallersTargetStub(Assembler* assembler) {
// Load code pointer to this stub from the thread:
// The one that is passed in, is not correct - it points to the code object
// that needs to be replaced.
__ ldr(CODE_REG, Address(THR, 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(R4);
__ Push(ZR);
__ CallRuntime(kFixCallersTargetRuntimeEntry, 0);
// Get Code object result and restore arguments descriptor array.
__ Pop(CODE_REG);
__ Pop(R4);
// Remove the stub frame.
__ LeaveStubFrame();
// Jump to the dart function.
__ LoadFieldFromOffset(R0, CODE_REG, Code::entry_point_offset());
__ br(R0);
}
// Called from object allocate instruction when the allocation stub has been
// disabled.
void StubCode::GenerateFixAllocationStubTargetStub(Assembler* assembler) {
// Load code pointer to this stub from the thread:
// The one that is passed in, is not correct - it points to the code object
// that needs to be replaced.
__ ldr(CODE_REG, Address(THR, 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, Code::entry_point_offset());
__ br(R0);
}
// Input parameters:
// R2: smi-tagged argument count, may be zero.
// FP[kParamEndSlotFromFp + 1]: last argument.
static void PushArrayOfArguments(Assembler* assembler) {
// Allocate array to store arguments of caller.
__ LoadObject(R1, Object::null_object());
// R1: null element type for raw Array.
// R2: smi-tagged argument count, may be zero.
__ BranchLink(StubCode::AllocateArray());
// 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.
__ add(R1, FP, Operand(R2, LSL, 2));
__ AddImmediate(R1, kParamEndSlotFromFp * kWordSize);
__ AddImmediate(R3, R0, Array::data_offset() - kHeapObjectTag);
// R1: address of first argument on stack.
// R3: address of first argument in array.
Label loop, loop_exit;
__ CompareRegisters(R2, ZR);
__ b(&loop_exit, LE);
__ Bind(&loop);
__ ldr(R7, Address(R1));
__ AddImmediate(R1, -kWordSize);
__ AddImmediate(R3, kWordSize);
__ AddImmediateSetFlags(R2, R2, -Smi::RawValue(1));
__ str(R7, Address(R3, -kWordSize));
__ b(&loop, GE);
__ 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 =
compiler::target::frame_layout.first_local_from_fp + 1 -
(kNumberOfCpuRegisters - R0);
const intptr_t saved_exception_slot_from_fp =
compiler::target::frame_layout.first_local_from_fp + 1 -
(kNumberOfCpuRegisters - R0);
const intptr_t saved_stacktrace_slot_from_fp =
compiler::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 * kWordSize));
__ str(R25, Address(SP, -1 * kWordSize, Address::PreIndex));
} else {
__ str(r, Address(SP, -1 * 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.
bool is_lazy =
(kind == kLazyDeoptFromReturn) || (kind == kLazyDeoptFromThrow);
__ LoadImmediate(R1, is_lazy ? 1 : 0);
__ ReserveAlignedFrameSpace(0);
__ CallRuntime(kDeoptimizeCopyFrameRuntimeEntry, 2);
// Result (R0) is stack-size (FP - SP) in bytes.
if (kind == kLazyDeoptFromReturn) {
// Restore result into R1 temporarily.
__ LoadFromOffset(R1, FP, saved_result_slot_from_fp * kWordSize);
} else if (kind == kLazyDeoptFromThrow) {
// Restore result into R1 temporarily.
__ LoadFromOffset(R1, FP, saved_exception_slot_from_fp * kWordSize);
__ LoadFromOffset(R2, FP, saved_stacktrace_slot_from_fp * 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.
}
__ ReserveAlignedFrameSpace(0);
__ mov(R0, FP); // Pass last FP as parameter in R0.
__ CallRuntime(kDeoptimizeFillFrameRuntimeEntry, 1);
if (kind == kLazyDeoptFromReturn) {
// Restore result into R1.
__ LoadFromOffset(
R1, FP, compiler::target::frame_layout.first_local_from_fp * kWordSize);
} else if (kind == kLazyDeoptFromThrow) {
// Restore result into R1.
__ LoadFromOffset(
R1, FP, compiler::target::frame_layout.first_local_from_fp * kWordSize);
__ LoadFromOffset(
R2, FP,
(compiler::target::frame_layout.first_local_from_fp - 1) * 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 StubCode::GenerateDeoptimizeLazyFromReturnStub(Assembler* assembler) {
// Push zap value instead of CODE_REG for lazy deopt.
__ LoadImmediate(TMP, kZapCodeReg);
__ Push(TMP);
// Return address for "call" to deopt stub.
__ LoadImmediate(LR, kZapReturnAddress);
__ ldr(CODE_REG, Address(THR, Thread::lazy_deopt_from_return_stub_offset()));
GenerateDeoptimizationSequence(assembler, kLazyDeoptFromReturn);
__ ret();
}
// R0: exception, must be preserved
// R1: stacktrace, must be preserved
void StubCode::GenerateDeoptimizeLazyFromThrowStub(Assembler* assembler) {
// Push zap value instead of CODE_REG for lazy deopt.
__ LoadImmediate(TMP, kZapCodeReg);
__ Push(TMP);
// Return address for "call" to deopt stub.
__ LoadImmediate(LR, kZapReturnAddress);
__ ldr(CODE_REG, Address(THR, Thread::lazy_deopt_from_throw_stub_offset()));
GenerateDeoptimizationSequence(assembler, kLazyDeoptFromThrow);
__ ret();
}
void StubCode::GenerateDeoptimizeStub(Assembler* assembler) {
__ Push(CODE_REG);
__ ldr(CODE_REG, Address(THR, Thread::deoptimize_stub_offset()));
GenerateDeoptimizationSequence(assembler, kEagerDeopt);
__ 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, Object::null_object());
__ b(call_target_function, NE);
__ EnterStubFrame();
// Load the receiver.
__ LoadFieldFromOffset(R2, R4, ArgumentsDescriptor::count_offset());
__ add(TMP, FP, Operand(R2, LSL, 2)); // R2 is Smi.
__ LoadFromOffset(R6, TMP, kParamEndSlotFromFp * kWordSize);
__ Push(ZR); // Result slot.
__ Push(R6); // Receiver.
__ Push(R5); // ICData/MegamorphicCache.
__ Push(R4); // Arguments descriptor.
// Adjust arguments count.
__ LoadFieldFromOffset(R3, R4, ArgumentsDescriptor::type_args_len_offset());
__ AddImmediate(TMP, R2, 1); // Include the type arguments.
__ cmp(R3, Operand(0));
__ csinc(R2, R2, TMP, EQ); // R2 <- (R3 == 0) ? R2 : TMP + 1 (R2 : R2 + 2).
// R2: Smi-tagged arguments array length.
PushArrayOfArguments(assembler);
const intptr_t kNumArgs = 4;
__ CallRuntime(kInvokeNoSuchMethodDispatcherRuntimeEntry, kNumArgs);
__ Drop(4);
__ Pop(R0); // Return value.
__ LeaveStubFrame();
__ ret();
}
void StubCode::GenerateMegamorphicMissStub(Assembler* assembler) {
__ EnterStubFrame();
// Load the receiver.
__ LoadFieldFromOffset(R2, R4, ArgumentsDescriptor::count_offset());
__ add(TMP, FP, Operand(R2, LSL, 2)); // R2 is Smi.
__ LoadFromOffset(
R6, TMP, compiler::target::frame_layout.param_end_from_fp * kWordSize);
// Preserve IC data and arguments descriptor.
__ Push(R5);
__ Push(R4);
// Push space for the return value.
// Push the receiver.
// Push IC data object.
// Push arguments descriptor array.
__ Push(ZR);
__ Push(R6);
__ Push(R5);
__ Push(R4);
__ CallRuntime(kMegamorphicCacheMissHandlerRuntimeEntry, 3);
// Remove arguments.
__ Drop(3);
__ Pop(R0); // Get result into R0 (target function).
// Restore IC data and arguments descriptor.
__ Pop(R4);
__ Pop(R5);
__ RestoreCodePointer();
__ LeaveStubFrame();
if (!FLAG_lazy_dispatchers) {
Label call_target_function;
GenerateDispatcherCode(assembler, &call_target_function);
__ Bind(&call_target_function);
}
// Tail-call to target function.
__ LoadFieldFromOffset(CODE_REG, R0, Function::code_offset());
__ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
__ br(R2);
}
// Called for inline allocation of arrays.
// Input parameters:
// LR: return address.
// R2: array length as Smi.
// R1: array element type (either NULL or an instantiated type).
// NOTE: R2 cannot be clobbered here as the caller relies on it being saved.
// The newly allocated object is returned in R0.
void StubCode::GenerateAllocateArrayStub(Assembler* assembler) {
Label slow_case;
// Compute the size to be allocated, it is based on the array length
// and is computed as:
// RoundedAllocationSize((array_length * kwordSize) + sizeof(RawArray)).
// Assert that length is a Smi.
__ tsti(R2, Immediate(kSmiTagMask));
if (FLAG_use_slow_path) {
__ b(&slow_case);
} else {
__ b(&slow_case, NE);
}
__ cmp(R2, Operand(0));
__ b(&slow_case, LT);
// Check for maximum allowed length.
const intptr_t max_len =
reinterpret_cast<intptr_t>(Smi::New(Array::kMaxNewSpaceElements));
__ CompareImmediate(R2, max_len);
__ b(&slow_case, GT);
const intptr_t cid = kArrayCid;
NOT_IN_PRODUCT(__ MaybeTraceAllocation(kArrayCid, R4, &slow_case));
// Calculate and align allocation size.
// Load new object start and calculate next object start.
// R1: array element type.
// R2: array length as Smi.
__ ldr(R0, Address(THR, Thread::top_offset()));
intptr_t fixed_size_plus_alignment_padding =
sizeof(RawArray) + kObjectAlignment - 1;
__ LoadImmediate(R3, fixed_size_plus_alignment_padding);
__ add(R3, R3, Operand(R2, LSL, 2)); // R2 is Smi.
ASSERT(kSmiTagShift == 1);
__ andi(R3, R3, Immediate(~(kObjectAlignment - 1)));
// R0: potential new object start.
// R3: object size in bytes.
__ adds(R7, R3, Operand(R0));
__ b(&slow_case, CS); // Branch if unsigned overflow.
// Check if the allocation fits into the remaining space.
// R0: potential new object start.
// R1: array element type.
// R2: array length as Smi.
// R3: array size.
// R7: potential next object start.
__ LoadFromOffset(TMP, THR, Thread::end_offset());
__ CompareRegisters(R7, TMP);
__ b(&slow_case, CS); // Branch if unsigned higher or equal.
// Successfully allocated the object(s), now update top to point to
// next object start and initialize the object.
// R0: potential new object start.
// R3: array size.
// R7: potential next object start.
__ str(R7, Address(THR, Thread::top_offset()));
__ add(R0, R0, Operand(kHeapObjectTag));
NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, R3));
// R0: new object start as a tagged pointer.
// R1: array element type.
// R2: array length as Smi.
// R3: array size.
// R7: new object end address.
// Store the type argument field.
__ StoreIntoObjectOffsetNoBarrier(R0, Array::type_arguments_offset(), R1);
// Set the length field.
__ StoreIntoObjectOffsetNoBarrier(R0, Array::length_offset(), R2);
// Calculate the size tag.
// R0: new object start as a tagged pointer.
// R2: array length as Smi.
// R3: array size.
// R7: new object end address.
const intptr_t shift = RawObject::kSizeTagPos - kObjectAlignmentLog2;
__ CompareImmediate(R3, RawObject::SizeTag::kMaxSizeTag);
// If no size tag overflow, shift R1 left, else set R1 to zero.
__ LslImmediate(TMP, R3, shift);
__ csel(R1, TMP, R1, LS);
__ csel(R1, ZR, R1, HI);
// Get the class index and insert it into the tags.
uint32_t tags = 0;
tags = RawObject::ClassIdTag::update(cid, tags);
tags = RawObject::NewBit::update(true, tags);
__ LoadImmediate(TMP, tags);
__ orr(R1, R1, Operand(TMP));
__ StoreFieldToOffset(R1, R0, Array::tags_offset());
// Initialize all array elements to raw_null.
// R0: new object start as a tagged pointer.
// R7: new object end address.
// R2: array length as Smi.
__ AddImmediate(R1, R0, Array::data_offset() - kHeapObjectTag);
// R1: iterator which initially points to the start of the variable
// data area to be initialized.
__ LoadObject(TMP, Object::null_object());
Label loop, done;
__ Bind(&loop);
// TODO(cshapiro): StoreIntoObjectNoBarrier
__ CompareRegisters(R1, R7);
__ b(&done, CS);
__ str(TMP, Address(R1)); // Store if unsigned lower.
__ AddImmediate(R1, kWordSize);
__ b(&loop); // Loop until R1 == R7.
__ Bind(&done);
// Done allocating and initializing the array.
// R0: new object.
// R2: array length as Smi (preserved for the caller.)
__ 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(R2);
__ Push(R1);
__ CallRuntime(kAllocateArrayRuntimeEntry, 2);
// Pop arguments; result is popped in IP.
__ Pop(R1);
__ Pop(R2);
__ Pop(R0);
__ LeaveStubFrame();
__ ret();
}
// Called when invoking Dart code from C++ (VM code).
// Input parameters:
// LR : points to return address.
// R0 : code object of the Dart function to call.
// R1 : arguments descriptor array.
// R2 : arguments array.
// R3 : current thread.
void StubCode::GenerateInvokeDartCodeStub(Assembler* assembler) {
__ Comment("InvokeDartCodeStub");
// Copy the C stack pointer (R31) into the stack pointer we'll actually use
// to access the stack.
__ SetupDartSP();
__ Push(LR); // Marker for the profiler.
__ EnterFrame(0);
// Push code object to PC marker slot.
__ ldr(TMP, Address(R3, Thread::invoke_dart_code_stub_offset()));
__ Push(TMP);
// Save the callee-saved registers.
for (int i = kAbiFirstPreservedCpuReg; i <= kAbiLastPreservedCpuReg; i++) {
const Register r = static_cast<Register>(i);
// We use str instead of the Push macro because we will be pushing the PP
// register when it is not holding a pool-pointer since we are coming from
// C++ code.
__ str(r, Address(SP, -1 * kWordSize, Address::PreIndex));
}
// Save the bottom 64-bits of callee-saved V registers.
for (int i = kAbiFirstPreservedFpuReg; i <= kAbiLastPreservedFpuReg; i++) {
const VRegister r = static_cast<VRegister>(i);
__ PushDouble(r);
}
// Set up THR, which caches the current thread in Dart code.
if (THR != R3) {
__ mov(THR, R3);
}
// Refresh write barrier mask.
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Save the current VMTag on the stack.
__ LoadFromOffset(R4, THR, 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, Thread::top_resource_offset());
__ StoreToOffset(ZR, THR, Thread::top_resource_offset());
__ Push(R6);
__ LoadFromOffset(R6, THR, Thread::top_exit_frame_info_offset());
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
// kExitLinkSlotFromEntryFp must be kept in sync with the code below.
ASSERT(kExitLinkSlotFromEntryFp == -22);
__ Push(R6);
// Mark that the thread is executing Dart code. Do this after initializing the
// exit link for the profiler.
__ LoadImmediate(R6, VMTag::kDartCompiledTagId);
__ StoreToOffset(R6, THR, Thread::vm_tag_offset());
// Load arguments descriptor array into R4, which is passed to Dart code.
__ LoadFromOffset(R4, R1, VMHandles::kOffsetOfRawPtrInHandle);
// Load number of arguments into R5 and adjust count for type arguments.
__ LoadFieldFromOffset(R5, R4, ArgumentsDescriptor::count_offset());
__ LoadFieldFromOffset(R3, R4, ArgumentsDescriptor::type_args_len_offset());
__ AddImmediate(TMP, R5, 1); // Include the type arguments.
__ cmp(R3, Operand(0));
__ csinc(R5, R5, TMP, EQ); // R5 <- (R3 == 0) ? R5 : TMP + 1 (R5 : R5 + 2).
__ SmiUntag(R5);
// Compute address of 'arguments array' data area into R2.
__ LoadFromOffset(R2, R2, VMHandles::kOffsetOfRawPtrInHandle);
__ AddImmediate(R2, 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);
__ ldr(R3, Address(R2));
__ Push(R3);
__ add(R1, R1, Operand(1));
__ add(R2, R2, Operand(kWordSize));
__ cmp(R1, Operand(R5));
__ b(&push_arguments, LT);
__ Bind(&done_push_arguments);
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ ldr(PP, Address(THR, Thread::global_object_pool_offset()));
__ sub(PP, PP, Operand(kHeapObjectTag)); // Pool in PP is untagged!
} 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, Object::null_object());
}
// Call the Dart code entrypoint.
__ ldr(CODE_REG, Address(R0, VMHandles::kOffsetOfRawPtrInHandle));
__ ldr(R0, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ blr(R0); // R4 is the arguments descriptor array.
__ Comment("InvokeDartCodeStub return");
// Get rid of arguments pushed on the stack.
__ AddImmediate(SP, FP, kExitLinkSlotFromEntryFp * 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, Thread::top_exit_frame_info_offset());
__ Pop(R6);
__ StoreToOffset(R6, THR, Thread::top_resource_offset());
// Restore the current VMTag from the stack.
__ Pop(R4);
__ StoreToOffset(R4, THR, Thread::vm_tag_offset());
// Restore the bottom 64-bits of callee-saved V registers.
for (int i = kAbiLastPreservedFpuReg; i >= kAbiFirstPreservedFpuReg; i--) {
const VRegister r = static_cast<VRegister>(i);
__ PopDouble(r);
}
// Restore C++ ABI callee-saved registers.
for (int i = kAbiLastPreservedCpuReg; i >= kAbiFirstPreservedCpuReg; i--) {
Register r = static_cast<Register>(i);
// We use ldr instead of the Pop macro because we will be popping the PP
// register when it is not holding a pool-pointer since we are returning to
// C++ code. We also skip the dart stack pointer SP, since we are still
// using it as the stack pointer.
__ ldr(r, Address(SP, 1 * kWordSize, Address::PostIndex));
}
// Restore the frame pointer and C stack pointer and return.
__ LeaveFrame();
__ Drop(1);
__ RestoreCSP();
__ ret();
}
// Called when invoking compiled Dart code from interpreted Dart code.
// Input parameters:
// LR : points to return address.
// R0 : raw code object of the Dart function to call.
// R1 : arguments raw descriptor array.
// R2 : address of first argument.
// R3 : current thread.
void StubCode::GenerateInvokeDartCodeFromBytecodeStub(Assembler* assembler) {
#if defined(DART_PRECOMPILED_RUNTIME)
__ Stop("Not using interpreter");
#else
// Copy the C stack pointer (R31) into the stack pointer we'll actually use
// to access the stack.
__ SetupDartSP();
__ Push(LR); // Marker for the profiler.
__ EnterFrame(0);
// Push code object to PC marker slot.
__ ldr(TMP,
Address(R3, Thread::invoke_dart_code_from_bytecode_stub_offset()));
__ Push(TMP);
// Save the callee-saved registers.
for (int i = kAbiFirstPreservedCpuReg; i <= kAbiLastPreservedCpuReg; i++) {
const Register r = static_cast<Register>(i);
// We use str instead of the Push macro because we will be pushing the PP
// register when it is not holding a pool-pointer since we are coming from
// C++ code.
__ str(r, Address(SP, -1 * kWordSize, Address::PreIndex));
}
// Save the bottom 64-bits of callee-saved V registers.
for (int i = kAbiFirstPreservedFpuReg; i <= kAbiLastPreservedFpuReg; i++) {
const VRegister r = static_cast<VRegister>(i);
__ PushDouble(r);
}
// Set up THR, which caches the current thread in Dart code.
if (THR != R3) {
__ mov(THR, R3);
}
// Refresh write barrier mask.
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Save the current VMTag on the stack.
__ LoadFromOffset(R4, THR, 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, Thread::top_resource_offset());
__ StoreToOffset(ZR, THR, Thread::top_resource_offset());
__ Push(R6);
__ LoadFromOffset(R6, THR, Thread::top_exit_frame_info_offset());
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
// kExitLinkSlotFromEntryFp must be kept in sync with the code below.
ASSERT(kExitLinkSlotFromEntryFp == -22);
__ Push(R6);
// Mark that the thread is executing Dart code. Do this after initializing the
// exit link for the profiler.
__ LoadImmediate(R6, VMTag::kDartCompiledTagId);
__ StoreToOffset(R6, THR, 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.
__ LoadFieldFromOffset(R5, R4, ArgumentsDescriptor::count_offset());
__ LoadFieldFromOffset(R3, R4, ArgumentsDescriptor::type_args_len_offset());
__ AddImmediate(TMP, R5, 1); // Include the type arguments.
__ cmp(R3, Operand(0));
__ csinc(R5, R5, TMP, EQ); // R5 <- (R3 == 0) ? R5 : TMP + 1 (R5 : R5 + 2).
__ SmiUntag(R5);
// R2 points to first argument.
// 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);
__ ldr(R3, Address(R2));
__ Push(R3);
__ add(R1, R1, Operand(1));
__ add(R2, R2, Operand(kWordSize));
__ cmp(R1, Operand(R5));
__ b(&push_arguments, LT);
__ Bind(&done_push_arguments);
// 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, Object::null_object());
// Call the Dart code entrypoint.
__ mov(CODE_REG, R0);
__ ldr(R0, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ blr(R0); // R4 is the arguments descriptor array.
// Get rid of arguments pushed on the stack.
__ AddImmediate(SP, FP, kExitLinkSlotFromEntryFp * 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, Thread::top_exit_frame_info_offset());
__ Pop(R6);
__ StoreToOffset(R6, THR, Thread::top_resource_offset());
// Restore the current VMTag from the stack.
__ Pop(R4);
__ StoreToOffset(R4, THR, Thread::vm_tag_offset());
// Restore the bottom 64-bits of callee-saved V registers.
for (int i = kAbiLastPreservedFpuReg; i >= kAbiFirstPreservedFpuReg; i--) {
const VRegister r = static_cast<VRegister>(i);
__ PopDouble(r);
}
// Restore C++ ABI callee-saved registers.
for (int i = kAbiLastPreservedCpuReg; i >= kAbiFirstPreservedCpuReg; i--) {
Register r = static_cast<Register>(i);
// We use ldr instead of the Pop macro because we will be popping the PP
// register when it is not holding a pool-pointer since we are returning to
// C++ code. We also skip the dart stack pointer SP, since we are still
// using it as the stack pointer.
__ ldr(r, Address(SP, 1 * kWordSize, Address::PostIndex));
}
// Restore the frame pointer and C stack pointer and return.
__ LeaveFrame();
__ Drop(1);
__ RestoreCSP();
__ ret();
#endif // defined(DART_PRECOMPILED_RUNTIME)
}
// Called for inline allocation of contexts.
// Input:
// R1: number of context variables.
// Output:
// R0: new allocated RawContext object.
void StubCode::GenerateAllocateContextStub(Assembler* assembler) {
if (FLAG_inline_alloc) {
Label slow_case;
// First compute the rounded instance size.
// R1: number of context variables.
intptr_t fixed_size_plus_alignment_padding =
sizeof(RawContext) + kObjectAlignment - 1;
__ LoadImmediate(R2, fixed_size_plus_alignment_padding);
__ add(R2, R2, Operand(R1, LSL, 3));
ASSERT(kSmiTagShift == 1);
__ andi(R2, R2, Immediate(~(kObjectAlignment - 1)));
NOT_IN_PRODUCT(__ MaybeTraceAllocation(kContextCid, R4, &slow_case));
// Now allocate the object.
// R1: number of context variables.
// R2: object size.
const intptr_t cid = kContextCid;
__ ldr(R0, Address(THR, 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, Thread::end_offset()));
__ CompareRegisters(R3, TMP);
if (FLAG_use_slow_path) {
__ b(&slow_case);
} else {
__ b(&slow_case, CS); // Branch if unsigned higher or equal.
}
// Successfully allocated the object, now update top to point to
// next object start and initialize the object.
// R0: new object.
// R1: number of context variables.
// R2: object size.
// R3: next object start.
__ str(R3, Address(THR, Thread::top_offset()));
__ add(R0, R0, Operand(kHeapObjectTag));
NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, R2));
// Calculate the size tag.
// R0: new object.
// R1: number of context variables.
// R2: object size.
const intptr_t shift = RawObject::kSizeTagPos - kObjectAlignmentLog2;
__ CompareImmediate(R2, RawObject::SizeTag::kMaxSizeTag);
// 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.
uint32_t tags = 0;
tags = RawObject::ClassIdTag::update(cid, tags);
tags = RawObject::NewBit::update(true, tags);
__ LoadImmediate(TMP, tags);
__ orr(R2, R2, Operand(TMP));
__ StoreFieldToOffset(R2, R0, Context::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, Context::num_variables_offset());
// Setup the parent field.
// R0: new object.
// R1: number of context variables.
__ LoadObject(R2, Object::null_object());
__ StoreFieldToOffset(R2, R0, Context::parent_offset());
// Initialize the context variables.
// R0: new object.
// R1: number of context variables.
// R2: raw null.
Label loop, done;
__ AddImmediate(R3, R0, Context::variable_offset(0) - kHeapObjectTag);
__ Bind(&loop);
__ subs(R1, R1, Operand(1));
__ b(&done, MI);
__ str(R2, Address(R3, R1, UXTX, Address::Scaled));
__ 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.
__ SmiTag(R1);
__ PushObject(Object::null_object());
__ Push(R1);
__ CallRuntime(kAllocateContextRuntimeEntry, 1); // Allocate context.
__ Drop(1); // Pop number of context variables argument.
__ Pop(R0); // Pop the new context object.
// R0: new object
// Restore the frame pointer.
__ LeaveStubFrame();
__ ret();
}
void StubCode::GenerateWriteBarrierWrappersStub(Assembler* assembler) {
for (intptr_t i = 0; i < kNumberOfCpuRegisters; ++i) {
if ((kDartAvailableCpuRegs & (1 << i)) == 0) continue;
Register reg = static_cast<Register>(i);
intptr_t start = __ CodeSize();
__ Push(LR);
__ Push(kWriteBarrierObjectReg);
__ mov(kWriteBarrierObjectReg, reg);
__ ldr(LR, Address(THR, Thread::write_barrier_entry_point_offset()));
__ blr(LR);
__ Pop(kWriteBarrierObjectReg);
__ Pop(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,
Address stub_code,
bool cards) {
Label add_to_mark_stack, remember_card;
__ tbz(&add_to_mark_stack, R0, kNewObjectBitPosition);
if (cards) {
__ LoadFieldFromOffset(TMP, R1, Object::tags_offset(), kWord);
__ tbnz(&remember_card, TMP, RawObject::kCardRememberedBit);
} else {
#if defined(DEBUG)
Label ok;
__ LoadFieldFromOffset(TMP, R1, Object::tags_offset(), kWord);
__ tbz(&ok, TMP, RawObject::kCardRememberedBit);
__ Stop("Wrong barrier");
__ Bind(&ok);
#endif
}
// Save values being destroyed.
__ Push(R2);
__ Push(R3);
__ Push(R4);
// Atomically set the remembered bit of the object header.
ASSERT(Object::tags_offset() == 0);
__ sub(R3, R1, Operand(kHeapObjectTag));
// R3: Untagged address of header word (ldxr/stxr do not support offsets).
// Note that we use 32 bit operations here to match the size of the
// background sweeper which is also manipulating this 32 bit word.
Label retry;
__ Bind(&retry);
__ ldxr(R2, R3, kWord);
__ AndImmediate(R2, R2, ~(1 << RawObject::kOldAndNotRememberedBit));
__ stxr(R4, R2, R3, kWord);
__ 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, Thread::store_buffer_block_offset());
__ LoadFromOffset(R2, R4, StoreBufferBlock::top_offset(), kUnsignedWord);
__ add(R3, R4, Operand(R2, LSL, kWordSizeLog2));
__ StoreToOffset(R1, R3, StoreBufferBlock::pointers_offset());
// Increment top_ and check for overflow.
// R2: top_.
// R4: StoreBufferBlock.
Label overflow;
__ add(R2, R2, Operand(1));
__ StoreToOffset(R2, R4, StoreBufferBlock::top_offset(), kUnsignedWord);
__ CompareImmediate(R2, StoreBufferBlock::kSize);
// Restore values.
__ Pop(R4);
__ Pop(R3);
__ Pop(R2);
__ b(&overflow, EQ);
__ ret();
// Handle overflow: Call the runtime leaf function.
__ Bind(&overflow);
// Setup frame, push callee-saved registers.
__ Push(CODE_REG);
__ ldr(CODE_REG, stub_code);
__ EnterCallRuntimeFrame(0 * kWordSize);
__ mov(R0, THR);
__ CallRuntime(kStoreBufferBlockProcessRuntimeEntry, 1);
// Restore callee-saved registers, tear down frame.
__ LeaveCallRuntimeFrame();
__ Pop(CODE_REG);
__ ret();
__ Bind(&add_to_mark_stack);
__ Push(R2); // Spill.
__ Push(R3); // Spill.
__ Push(R4); // Spill.
// Atomically clear kOldAndNotMarkedBit.
// Note that we use 32 bit operations here to match the size of the
// background sweeper which is also manipulating this 32 bit word.
Label marking_retry, lost_race, marking_overflow;
ASSERT(Object::tags_offset() == 0);
__ sub(R3, R0, Operand(kHeapObjectTag));
// R3: Untagged address of header word (ldxr/stxr do not support offsets).
__ Bind(&marking_retry);
__ ldxr(R2, R3, kWord);
__ tbz(&lost_race, R2, RawObject::kOldAndNotMarkedBit);
__ AndImmediate(R2, R2, ~(1 << RawObject::kOldAndNotMarkedBit));
__ stxr(R4, R2, R3, kWord);
__ cbnz(&marking_retry, R4);
__ LoadFromOffset(R4, THR, Thread::marking_stack_block_offset());
__ LoadFromOffset(R2, R4, MarkingStackBlock::top_offset(), kUnsignedWord);
__ add(R3, R4, Operand(R2, LSL, kWordSizeLog2));
__ StoreToOffset(R0, R3, MarkingStackBlock::pointers_offset());
__ add(R2, R2, Operand(1));
__ StoreToOffset(R2, R4, MarkingStackBlock::top_offset(), kUnsignedWord);
__ CompareImmediate(R2, MarkingStackBlock::kSize);
__ Pop(R4); // Unspill.
__ Pop(R3); // Unspill.
__ Pop(R2); // Unspill.
__ b(&marking_overflow, EQ);
__ ret();
__ Bind(&marking_overflow);
__ Push(CODE_REG);
__ ldr(CODE_REG, stub_code);
__ EnterCallRuntimeFrame(0 * kWordSize);
__ mov(R0, THR);
__ CallRuntime(kMarkingStackBlockProcessRuntimeEntry, 1);
__ LeaveCallRuntimeFrame();
__ Pop(CODE_REG);
__ ret();
__ Bind(&lost_race);
__ Pop(R4); // Unspill.
__ Pop(R3); // Unspill.
__ Pop(R2); // Unspill.
__ ret();
if (cards) {
Label remember_card_slow;
// Get card table.
__ Bind(&remember_card);
__ AndImmediate(TMP, R1, kPageMask); // HeapPage.
__ ldr(TMP, Address(TMP, HeapPage::card_table_offset())); // Card table.
__ cbz(&remember_card_slow, TMP);
// Dirty the card.
__ AndImmediate(TMP, R1, kPageMask); // HeapPage.
__ sub(R25, R25, Operand(TMP)); // Offset in page.
__ ldr(TMP, Address(TMP, HeapPage::card_table_offset())); // Card table.
__ add(TMP, TMP,
Operand(R25, LSR, HeapPage::kBytesPerCardLog2)); // Card address.
__ str(R1, Address(TMP, 0),
kUnsignedByte); // Low byte of R1 is non-zero from object tag.
__ ret();
// Card table not yet allocated.
__ Bind(&remember_card_slow);
__ Push(CODE_REG);
__ PushPair(R0, R1);
__ ldr(CODE_REG, stub_code);
__ mov(R0, R1); // Arg0 = Object
__ mov(R1, R25); // Arg1 = Slot
__ EnterCallRuntimeFrame(0);
__ CallRuntime(kRememberCardRuntimeEntry, 2);
__ LeaveCallRuntimeFrame();
__ PopPair(R0, R1);
__ Pop(CODE_REG);
__ ret();
}
}
void StubCode::GenerateWriteBarrierStub(Assembler* assembler) {
GenerateWriteBarrierStubHelper(
assembler, Address(THR, Thread::write_barrier_code_offset()), false);
}
void StubCode::GenerateArrayWriteBarrierStub(Assembler* assembler) {
GenerateWriteBarrierStubHelper(
assembler, Address(THR, Thread::array_write_barrier_code_offset()), true);
}
// Called for inline allocation of objects.
// Input parameters:
// LR : return address.
// SP + 0 : type arguments object (only if class is parameterized).
void StubCode::GenerateAllocationStubForClass(Assembler* assembler,
const Class& cls) {
// The generated code is different if the class is parameterized.
const bool is_cls_parameterized = cls.NumTypeArguments() > 0;
ASSERT(!is_cls_parameterized ||
(cls.type_arguments_field_offset() != Class::kNoTypeArguments));
const Register kTypeArgumentsReg = R1;
const Register kInstanceReg = R0;
const Register kNullReg = R3;
const Register kTempReg = R4;
const Register kTopReg = R5;
// kInlineInstanceSize is a constant used as a threshold for determining
// when the object initialization should be done as a loop or as
// straight line code.
const int kInlineInstanceSize = 12;
const intptr_t instance_size = cls.instance_size();
ASSERT(instance_size > 0);
if (is_cls_parameterized) {
__ ldr(kTypeArgumentsReg, Address(SP));
}
Isolate* isolate = Isolate::Current();
__ LoadObject(kNullReg, Object::null_object());
if (FLAG_inline_alloc && Heap::IsAllocatableInNewSpace(instance_size) &&
!cls.TraceAllocation(isolate)) {
Label slow_case;
// Allocate the object & initialize header word.
__ TryAllocate(cls, &slow_case, kInstanceReg, kTopReg,
/*tag_result=*/false);
// Initialize the remaining words of the object.
if (instance_size < (kInlineInstanceSize * kWordSize)) {
intptr_t current_offset = Instance::NextFieldOffset();
while ((current_offset + kWordSize) < instance_size) {
__ stp(kNullReg, kNullReg,
Address(kInstanceReg, current_offset, Address::PairOffset));
current_offset += 2 * kWordSize;
}
while (current_offset < instance_size) {
__ str(kNullReg, Address(kInstanceReg, current_offset));
current_offset += kWordSize;
}
} else {
__ AddImmediate(kTempReg, kInstanceReg, Instance::NextFieldOffset());
Label done, init_loop;
__ Bind(&init_loop);
__ CompareRegisters(kTempReg, kTopReg);
__ b(&done, CS);
__ str(kNullReg, Address(kTempReg, kWordSize, Address::PostIndex));
__ b(&init_loop);
__ Bind(&done);
}
if (is_cls_parameterized) {
__ StoreToOffset(kTypeArgumentsReg, kInstanceReg,
cls.type_arguments_field_offset());
}
__ add(kInstanceReg, kInstanceReg, Operand(kHeapObjectTag));
__ ret();
__ Bind(&slow_case);
}
// If is_cls_parameterized:
// Create a stub frame as we are pushing some objects on the stack before
// calling into the runtime.
__ EnterStubFrame(); // Uses pool pointer to pass cls to runtime.
__ LoadObject(R0, cls);
__ PushPair(R0, kNullReg); // Pushes cls, result slot.
__ Push(is_cls_parameterized ? kTypeArgumentsReg : kNullReg);
__ CallRuntime(kAllocateObjectRuntimeEntry, 2); // Allocate object.
__ ldr(kInstanceReg,
Address(SP, 2 * kWordSize)); // Pop result (newly allocated object).
__ LeaveStubFrame(); // Restores correct SP.
__ ret();
}
// 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 StubCode::GenerateCallClosureNoSuchMethodStub(Assembler* assembler) {
__ EnterStubFrame();
// Load the receiver.
__ LoadFieldFromOffset(R2, R4, ArgumentsDescriptor::count_offset());
__ add(TMP, FP, Operand(R2, LSL, 2)); // R2 is Smi.
__ LoadFromOffset(R6, TMP, kParamEndSlotFromFp * kWordSize);
// Push space for the return value.
// Push the receiver.
// Push arguments descriptor array.
__ Push(ZR);
__ Push(R6);
__ Push(R4);
// Adjust arguments count.
__ LoadFieldFromOffset(R3, R4, ArgumentsDescriptor::type_args_len_offset());
__ AddImmediate(TMP, R2, 1); // Include the type arguments.
__ cmp(R3, Operand(0));
__ csinc(R2, R2, TMP, EQ); // R2 <- (R3 == 0) ? R2 : TMP + 1 (R2 : R2 + 2).
// R2: Smi-tagged arguments array length.
PushArrayOfArguments(assembler);
const intptr_t kNumArgs = 3;
__ CallRuntime(kInvokeClosureNoSuchMethodRuntimeEntry, 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 StubCode::GenerateOptimizedUsageCounterIncrement(Assembler* assembler) {
Register ic_reg = R5;
Register func_reg = R6;
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, Function::usage_counter_offset(), kWord);
__ add(R7, R7, Operand(1));
__ StoreFieldToOffset(R7, func_reg, Function::usage_counter_offset(), kWord);
}
// Loads function into 'temp_reg'.
void StubCode::GenerateUsageCounterIncrement(Assembler* assembler,
Register temp_reg) {
if (FLAG_optimization_counter_threshold >= 0) {
Register ic_reg = R5;
Register func_reg = temp_reg;
ASSERT(temp_reg == R6);
__ Comment("Increment function counter");
__ LoadFieldFromOffset(func_reg, ic_reg, ICData::owner_offset());
__ LoadFieldFromOffset(R7, func_reg, Function::usage_counter_offset(),
kWord);
__ AddImmediate(R7, 1);
__ StoreFieldToOffset(R7, func_reg, Function::usage_counter_offset(),
kWord);
}
}
// 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, +0 * kWordSize)); // Right.
__ ldr(R1, Address(SP, +1 * kWordSize)); // Left.
__ orr(TMP, R0, Operand(R1));
__ BranchIfNotSmi(TMP, not_smi_or_overflow);
switch (kind) {
case Token::kADD: {
__ adds(R0, R1, Operand(R0)); // Adds.
__ b(not_smi_or_overflow, VS); // Branch if overflow.
break;
}
case Token::kSUB: {
__ subs(R0, R1, Operand(R0)); // Subtract.
__ b(not_smi_or_overflow, VS); // Branch if overflow.
break;
}
case Token::kEQ: {
__ CompareRegisters(R0, R1);
__ LoadObject(R0, Bool::True());
__ LoadObject(R1, Bool::False());
__ csel(R0, R1, R0, NE);
break;
}
default:
UNIMPLEMENTED();
}
// R5: IC data object (preserved).
__ LoadFieldFromOffset(R6, R5, ICData::ic_data_offset());
// R6: ic_data_array with check entries: classes and target functions.
__ AddImmediate(R6, 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 = reinterpret_cast<intptr_t>(Smi::New(kSmiCid));
__ ldr(R1, Address(R6, 0));
__ CompareImmediate(R1, imm_smi_cid);
__ b(&error, NE);
__ ldr(R1, Address(R6, kWordSize));
__ CompareImmediate(R1, imm_smi_cid);
__ b(&ok, EQ);
__ Bind(&error);
__ Stop("Incorrect IC data");
__ Bind(&ok);
#endif
if (FLAG_optimization_counter_threshold >= 0) {
const intptr_t count_offset = ICData::CountIndexFor(num_args) * kWordSize;
// Update counter, ignore overflow.
__ LoadFromOffset(R1, R6, count_offset);
__ adds(R1, R1, Operand(Smi::RawValue(1)));
__ StoreToOffset(R1, R6, count_offset);
}
__ ret();
}
// Generate inline cache check for 'num_args'.
// LR: return address.
// R5: inline cache data object.
// 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 StubCode::GenerateNArgsCheckInlineCacheStub(
Assembler* assembler,
intptr_t num_args,
const RuntimeEntry& handle_ic_miss,
Token::Kind kind,
bool optimized,
bool exactness_check /* = false */) {
ASSERT(!exactness_check);
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, ICData::state_bits_offset() - kHeapObjectTag,
kUnsignedWord);
ASSERT(ICData::NumArgsTestedShift() == 0); // No shift needed.
__ andi(R6, R6, Immediate(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) {
__ Comment("Check single stepping");
__ LoadIsolate(R6);
__ LoadFromOffset(R6, R6, 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");
// Load arguments descriptor into R4.
__ LoadFieldFromOffset(R4, R5, ICData::arguments_descriptor_offset());
// Loop that checks if there is an IC data match.
Label loop, found, miss;
// R5: IC data object (preserved).
__ LoadFieldFromOffset(R6, R5, ICData::ic_data_offset());
// R6: ic_data_array with check entries: classes and target functions.
__ AddImmediate(R6, Array::data_offset() - kHeapObjectTag);
// R6: points directly to the first ic data array element.
// Get the receiver's class ID (first read number of arguments from
// arguments descriptor array and then access the receiver from the stack).
__ LoadFieldFromOffset(R7, R4, 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(R0, R0);
if (num_args == 2) {
__ AddImmediate(R1, R7, -1);
// R1 <- [SP + (R1 << 3)]
__ ldr(R1, Address(SP, R1, UXTX, Address::Scaled));
__ LoadTaggedClassIdMayBeSmi(R1, R1);
}
// We unroll the generic one that is generated once more than the others.
const bool optimize = kind == Token::kILLEGAL;
__ Comment("ICData loop");
__ Bind(&loop);
for (int unroll = optimize ? 4 : 2; unroll >= 0; unroll--) {
Label update;
__ LoadFromOffset(R2, R6, 0);
__ CompareRegisters(R0, R2); // Class id match?
if (num_args == 2) {
__ b(&update, NE); // Continue.
__ LoadFromOffset(R2, R6, kWordSize);
__ CompareRegisters(R1, R2); // Class id match?
}
__ b(&found, EQ); // Break.
__ Bind(&update);
const intptr_t entry_size =
ICData::TestEntryLengthFor(num_args, exactness_check) * kWordSize;
__ AddImmediate(R6, entry_size); // Next entry.
__ CompareImmediate(R2, Smi::RawValue(kIllegalCid)); // Done?
if (unroll == 0) {
__ b(&loop, NE);
} else {
__ b(&miss, EQ);
}
}
__ Bind(&miss);
__ Comment("IC miss");
// Compute address of arguments.
// 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(R4); // Preserve arguments descriptor array.
__ Push(R5); // Preserve IC Data.
// 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 * 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(R0); // Pop returned function object into R0.
__ Pop(R5); // Restore IC Data.
__ Pop(R4); // 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);
__ Comment("Update caller's counter");
// R6: pointer to an IC data check group.
const intptr_t target_offset = ICData::TargetIndexFor(num_args) * kWordSize;
const intptr_t count_offset = ICData::CountIndexFor(num_args) * kWordSize;
__ LoadFromOffset(R0, R6, target_offset);
if (FLAG_optimization_counter_threshold >= 0) {
// Update counter, ignore overflow.
__ LoadFromOffset(R1, R6, count_offset);
__ adds(R1, R1, Operand(Smi::RawValue(1)));
__ StoreToOffset(R1, R6, count_offset);
}
__ Comment("Call target");
__ Bind(&call_target_function);
// R0: target function.
__ LoadFieldFromOffset(CODE_REG, R0, Function::code_offset());
__ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
__ br(R2);
#if !defined(PRODUCT)
if (!optimized) {
__ Bind(&stepping);
__ EnterStubFrame();
__ Push(R5); // Preserve IC data.
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ Pop(R5);
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
}
#endif
}
// Use inline cache data array to invoke the target or continue in inline
// cache miss handler. Stub for 1-argument check (receiver class).
// LR: return address.
// R5: inline cache data object.
// Inline cache data object structure:
// 0: function-name
// 1: N, number of arguments checked.
// 2 .. (length - 1): group of checks, each check containing:
// - N classes.
// - 1 target function.
void StubCode::GenerateOneArgCheckInlineCacheStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(
assembler, 1, kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL);
}
void StubCode::GenerateOneArgCheckInlineCacheWithExactnessCheckStub(
Assembler* assembler) {
__ Stop("Unimplemented");
}
void StubCode::GenerateTwoArgsCheckInlineCacheStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(assembler, 2,
kInlineCacheMissHandlerTwoArgsRuntimeEntry,
Token::kILLEGAL);
}
void StubCode::GenerateSmiAddInlineCacheStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kADD);
}
void StubCode::GenerateSmiSubInlineCacheStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kSUB);
}
void StubCode::GenerateSmiEqualInlineCacheStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kEQ);
}
void StubCode::GenerateOneArgOptimizedCheckInlineCacheStub(
Assembler* assembler) {
GenerateOptimizedUsageCounterIncrement(assembler);
GenerateNArgsCheckInlineCacheStub(assembler, 1,
kInlineCacheMissHandlerOneArgRuntimeEntry,
Token::kILLEGAL, true /* optimized */);
}
void StubCode::GenerateOneArgOptimizedCheckInlineCacheWithExactnessCheckStub(
Assembler* assembler) {
__ Stop("Unimplemented");
}
void StubCode::GenerateTwoArgsOptimizedCheckInlineCacheStub(
Assembler* assembler) {
GenerateOptimizedUsageCounterIncrement(assembler);
GenerateNArgsCheckInlineCacheStub(assembler, 2,
kInlineCacheMissHandlerTwoArgsRuntimeEntry,
Token::kILLEGAL, true /* optimized */);
}
void StubCode::GenerateZeroArgsUnoptimizedStaticCallStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, 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, ICData::state_bits_offset() - kHeapObjectTag,
kUnsignedWord);
ASSERT(ICData::NumArgsTestedShift() == 0); // No shift needed.
__ andi(R6, R6, Immediate(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, Isolate::single_step_offset(), kUnsignedByte);
__ CompareImmediate(R6, 0);
__ b(&stepping, NE);
__ Bind(&done_stepping);
#endif
// R5: IC data object (preserved).
__ LoadFieldFromOffset(R6, R5, ICData::ic_data_offset());
// R6: ic_data_array with entries: target functions and count.
__ AddImmediate(R6, Array::data_offset() - kHeapObjectTag);
// R6: points directly to the first ic data array element.
const intptr_t target_offset = ICData::TargetIndexFor(0) * kWordSize;
const intptr_t count_offset = ICData::CountIndexFor(0) * kWordSize;
if (FLAG_optimization_counter_threshold >= 0) {
// Increment count for this call, ignore overflow.
__ LoadFromOffset(R1, R6, count_offset);
__ adds(R1, R1, Operand(Smi::RawValue(1)));
__ StoreToOffset(R1, R6, count_offset);
}
// Load arguments descriptor into R4.
__ LoadFieldFromOffset(R4, R5, ICData::arguments_descriptor_offset());
// Get function and call it, if possible.
__ LoadFromOffset(R0, R6, target_offset);
__ LoadFieldFromOffset(CODE_REG, R0, Function::code_offset());
__ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
__ br(R2);
#if !defined(PRODUCT)
__ Bind(&stepping);
__ EnterStubFrame();
__ Push(R5); // Preserve IC data.
__ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
__ Pop(R5);
__ RestoreCodePointer();
__ LeaveStubFrame();
__ b(&done_stepping);
#endif
}
void StubCode::GenerateOneArgUnoptimizedStaticCallStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(
assembler, 1, kStaticCallMissHandlerOneArgRuntimeEntry, Token::kILLEGAL);
}
void StubCode::GenerateTwoArgsUnoptimizedStaticCallStub(Assembler* assembler) {
GenerateUsageCounterIncrement(assembler, R6);
GenerateNArgsCheckInlineCacheStub(
assembler, 2, kStaticCallMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL);
}
// Stub for compiling a function and jumping to the compiled code.
// R4: Arguments descriptor.
// R0: Function.
void StubCode::GenerateLazyCompileStub(Assembler* assembler) {
// Preserve arg desc.
__ EnterStubFrame();
__ Push(R4); // Save arg. desc.
__ Push(R0); // Pass function.
__ CallRuntime(kCompileFunctionRuntimeEntry, 1);
__ Pop(R0); // Restore argument.
__ Pop(R4); // Restore arg desc.
__ LeaveStubFrame();
// When using the interpreter, the function's code may now point to the
// InterpretCall stub. Make sure R0, R4, and R5 are preserved.
__ LoadFieldFromOffset(CODE_REG, R0, Function::code_offset());
__ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
__ br(R2);
}
// Stub for interpreting a function call.
// R4: Arguments descriptor.
// R0: Function.
void StubCode::GenerateInterpretCallStub(Assembler* assembler) {
#if defined(DART_PRECOMPILED_RUNTIME)
__ Stop("Not using interpreter")
#else
__ SetPrologueOffset();
__ EnterStubFrame();
#if defined(DEBUG)
{
Label ok;
// Check that we are always entering from Dart code.
__ LoadFromOffset(R8, THR, Thread::vm_tag_offset());
__ CompareImmediate(R8, VMTag::kDartCompiledTagId);
__ b(&ok, EQ);
__ Stop("Not coming from Dart code.");
__ Bind(&ok);
}
#endif
// Adjust arguments count for type arguments vector.
__ LoadFieldFromOffset(R2, R4, ArgumentsDescriptor::count_offset());
__ SmiUntag(R2);
__ LoadFieldFromOffset(R1, R4, ArgumentsDescriptor::type_args_len_offset());
__ cmp(R1, Operand(0));
__ csinc(R2, R2, R2, EQ); // R2 <- (R1 == 0) ? R2 : R2 + 1.
// Compute argv.
__ add(R3, ZR, Operand(R2, LSL, 3));
__ add(R3, FP, Operand(R3));
__ AddImmediate(R3, kParamEndSlotFromFp * kWordSize);
// Indicate decreasing memory addresses of arguments with negative argc.
__ neg(R2, R2);
// Align frame before entering C++ world. No shadow stack space required.
__ ReserveAlignedFrameSpace(0 * kWordSize);
// Pass arguments in registers.
// R0: Function.
__ mov(R1, R4); // Arguments descriptor.
// R2: Negative argc.
// R3: Argv.
__ mov(R4, THR); // Thread.
// Save exit frame information to enable stack walking as we are about
// to transition to Dart VM C++ code.
__ StoreToOffset(FP, THR, Thread::top_exit_frame_info_offset());
// Mark that the thread is executing VM code.
__ LoadFromOffset(R5, THR, Thread::interpret_call_entry_point_offset());
__ StoreToOffset(R5, THR, Thread::vm_tag_offset());
// 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);
// Restore SP and CSP.
__ mov(SP, CSP);
__ mov(CSP, R25);
// Refresh write barrier mask.
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Mark that the thread is executing Dart code.
__ LoadImmediate(R2, VMTag::kDartCompiledTagId);
__ StoreToOffset(R2, THR, Thread::vm_tag_offset());
// Reset exit frame information in Isolate structure.
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
__ LeaveStubFrame();
__ ret();
#endif // defined(DART_PRECOMPILED_RUNTIME)
}
// R5: Contains an ICData.
void StubCode::GenerateICCallBreakpointStub(Assembler* assembler) {
__ EnterStubFrame();
__ Push(R5);
__ Push(ZR); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG);
__ Pop(R5);
__ LeaveStubFrame();
__ LoadFieldFromOffset(R0, CODE_REG, Code::entry_point_offset());
__ br(R0);
}
void StubCode::GenerateRuntimeCallBreakpointStub(Assembler* assembler) {
__ EnterStubFrame();
__ Push(ZR); // Space for result.
__ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
__ Pop(CODE_REG);
__ LeaveStubFrame();
__ LoadFieldFromOffset(R0, CODE_REG, Code::entry_point_offset());
__ br(R0);
}
// Called only from unoptimized code. All relevant registers have been saved.
void StubCode::GenerateDebugStepCheckStub(Assembler* assembler) {
// Check single stepping.
Label stepping, done_stepping;
__ LoadIsolate(R1);
__ LoadFromOffset(R1, R1, 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);
}
// Used to check class and type arguments. Arguments passed in registers:
// LR: return address.
// R0: instance (must be preserved).
// R1: instantiator type arguments (only if n == 4, can be raw_null).
// R2: function type arguments (only if n == 4, can be raw_null).
// R3: SubtypeTestCache.
//
// Preserves R0/R2/R8.
//
// Result in R1: null -> not found, otherwise result (true or false).
static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
ASSERT(n == 1 || n == 2 || n == 4 || n == 6);
const Register kCacheReg = R3;
const Register kInstanceReg = R0;
const Register kInstantiatorTypeArgumentsReg = R1;
const Register kFunctionTypeArgumentsReg = R2;
const Register kInstanceCidOrFunction = R6;
const Register kInstanceInstantiatorTypeArgumentsReg = R4;
const Register kInstanceParentFunctionTypeArgumentsReg = R9;
const Register kInstanceDelayedFunctionTypeArgumentsReg = R10;
const Register kNullReg = R7;
__ LoadObject(kNullReg, Object::null_object());
// Loop initialization (moved up here to avoid having all dependent loads
// after each other).
__ ldr(kCacheReg, FieldAddress(kCacheReg, SubtypeTestCache::cache_offset()));
__ AddImmediate(kCacheReg, Array::data_offset() - kHeapObjectTag);
Label loop, not_closure;
if (n >= 4) {
__ LoadClassIdMayBeSmi(kInstanceCidOrFunction, kInstanceReg);
} else {
__ LoadClassId(kInstanceCidOrFunction, kInstanceReg);
}
__ CompareImmediate(kInstanceCidOrFunction, kClosureCid);
__ b(&not_closure, NE);
// Closure handling.
{
__ ldr(kInstanceCidOrFunction,
FieldAddress(kInstanceReg, Closure::function_offset()));
if (n >= 2) {
__ ldr(kInstanceInstantiatorTypeArgumentsReg,
FieldAddress(kInstanceReg,
Closure::instantiator_type_arguments_offset()));
if (n >= 6) {
ASSERT(n == 6);
__ ldr(kInstanceParentFunctionTypeArgumentsReg,
FieldAddress(kInstanceReg,
Closure::function_type_arguments_offset()));
__ ldr(kInstanceDelayedFunctionTypeArgumentsReg,
FieldAddress(kInstanceReg,
Closure::delayed_type_arguments_offset()));
}
}
__ b(&loop);
}
// Non-Closure handling.
{
__ Bind(&not_closure);
if (n == 1) {
__ SmiTag(kInstanceCidOrFunction);
} else {
ASSERT(n >= 2);
Label has_no_type_arguments;
// [LoadClassById] also tags [kInstanceCidOrFunction] as a side-effect.
__ LoadClassById(R5, kInstanceCidOrFunction);
__ mov(kInstanceInstantiatorTypeArgumentsReg, kNullReg);
__ LoadFieldFromOffset(
R5, R5, Class::type_arguments_field_offset_in_words_offset(), kWord);
__ CompareImmediate(R5, Class::kNoTypeArguments);
__ b(&has_no_type_arguments, EQ);
__ add(R5, kInstanceReg, Operand(R5, LSL, 3));
__ ldr(kInstanceInstantiatorTypeArgumentsReg, FieldAddress(R5, 0));
__ Bind(&has_no_type_arguments);
if (n >= 6) {
__ mov(kInstanceParentFunctionTypeArgumentsReg, kNullReg);
__ mov(kInstanceDelayedFunctionTypeArgumentsReg, kNullReg);
}
}
}
Label found, not_found, next_iteration;
// Loop header
__ Bind(&loop);
__ ldr(R5, Address(kCacheReg,
kWordSize * SubtypeTestCache::kInstanceClassIdOrFunction));
__ cmp(R5, Operand(kNullReg));
__ b(&not_found, EQ);
__ cmp(R5, Operand(kInstanceCidOrFunction));
if (n == 1) {
__ b(&found, EQ);
} else {
__ b(&next_iteration, NE);
__ ldr(R5, Address(kCacheReg,
kWordSize * SubtypeTestCache::kInstanceTypeArguments));
__ cmp(R5, Operand(kInstanceInstantiatorTypeArgumentsReg));
if (n == 2) {
__ b(&found, EQ);
} else {
__ b(&next_iteration, NE);
__ ldr(R5,
Address(kCacheReg,
kWordSize * SubtypeTestCache::kInstantiatorTypeArguments));
__ cmp(R5, Operand(kInstantiatorTypeArgumentsReg));
__ b(&next_iteration, NE);
__ ldr(R5, Address(kCacheReg,
kWordSize * SubtypeTestCache::kFunctionTypeArguments));
__ cmp(R5, Operand(kFunctionTypeArgumentsReg));
if (n == 4) {
__ b(&found, EQ);
} else {
ASSERT(n == 6);
__ b(&next_iteration, NE);
__ ldr(R5,
Address(
kCacheReg,
kWordSize *
SubtypeTestCache::kInstanceParentFunctionTypeArguments));
__ cmp(R5, Operand(kInstanceParentFunctionTypeArgumentsReg));
__ b(&next_iteration, NE);
__ ldr(
R5,
Address(
kCacheReg,
kWordSize *
SubtypeTestCache::kInstanceDelayedFunctionTypeArguments));
__ cmp(R5, Operand(kInstanceDelayedFunctionTypeArgumentsReg));
__ b(&found, EQ);
}
}
}
__ Bind(&next_iteration);
__ AddImmediate(kCacheReg, kWordSize * SubtypeTestCache::kTestEntryLength);
__ b(&loop);
__ Bind(&found);
__ ldr(R1, Address(kCacheReg, kWordSize * SubtypeTestCache::kTestResult));
__ ret();
__ Bind(&not_found);
__ mov(R1, kNullReg);
__ ret();
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCode::GenerateSubtype1TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 1);
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCode::GenerateSubtype2TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 2);
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCode::GenerateSubtype4TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 4);
}
// See comment on [GenerateSubtypeNTestCacheStub].
void StubCode::GenerateSubtype6TestCacheStub(Assembler* assembler) {
GenerateSubtypeNTestCacheStub(assembler, 6);
}
// Used to test whether a given value is of a given type (different variants,
// all have the same calling convention).
//
// Inputs:
// - R0 : instance to test against.
// - R2 : instantiator type arguments (if needed).
// - R1 : function type arguments (if needed).
//
// - R3 : subtype test cache.
//
// - R8 : type to test against.
// - R4 : name of destination variable.
//
// Preserves R0/R2.
//
// Note of warning: The caller will not populate CODE_REG and we have therefore
// no access to the pool.
void StubCode::GenerateDefaultTypeTestStub(Assembler* assembler) {
Label done;
const Register kInstanceReg = R0;
const Register kDstTypeReg = R8;
// Fast case for 'null'.
__ CompareObject(kInstanceReg, Object::null_object());
__ BranchIf(EQUAL, &done);
// Fast case for 'int'.
Label not_smi;
__ BranchIfNotSmi(kInstanceReg, &not_smi);
__ CompareObject(kDstTypeReg, Object::ZoneHandle(Type::IntType()));
__ BranchIf(EQUAL, &done);
__ Bind(&not_smi);
// Tail call the [SubtypeTestCache]-based implementation.
__ ldr(CODE_REG, Address(THR, Thread::slow_type_test_stub_offset()));
__ ldr(R9, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ br(R9);
__ Bind(&done);
__ Ret();
}
void StubCode::GenerateTopTypeTypeTestStub(Assembler* assembler) {
__ Ret();
}
void StubCode::GenerateTypeRefTypeTestStub(Assembler* assembler) {
const Register kTypeRefReg = R8;
// We dereference the TypeRef and tail-call to it's type testing stub.
__ ldr(kTypeRefReg, FieldAddress(kTypeRefReg, TypeRef::type_offset()));
__ ldr(R9, FieldAddress(kTypeRefReg,
AbstractType::type_test_stub_entry_point_offset()));
__ br(R9);
}
void StubCode::GenerateUnreachableTypeTestStub(Assembler* assembler) {
__ Breakpoint();
}
void TypeTestingStubGenerator::BuildOptimizedTypeTestStub(
Assembler* assembler,
HierarchyInfo* hi,
const Type& type,
const Class& type_class) {
const Register kInstanceReg = R0;
const Register kClassIdReg = R9;
BuildOptimizedTypeTestStubFastCases(assembler, hi, type, type_class,
kInstanceReg, kClassIdReg);
__ ldr(CODE_REG, Address(THR, Thread::slow_type_test_stub_offset()));
__ ldr(R9, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ br(R9);
}
void TypeTestingStubGenerator::
BuildOptimizedSubclassRangeCheckWithTypeArguments(Assembler* assembler,
HierarchyInfo* hi,
const Class& type_class,
const TypeArguments& tp,
const TypeArguments& ta) {
const Register kInstanceReg = R0;
const Register kInstanceTypeArguments = R7;
const Register kClassIdReg = R9;
BuildOptimizedSubclassRangeCheckWithTypeArguments(
assembler, hi, type_class, tp, ta, kClassIdReg, kInstanceReg,
kInstanceTypeArguments);
}
void TypeTestingStubGenerator::BuildOptimizedTypeArgumentValueCheck(
Assembler* assembler,
HierarchyInfo* hi,
const AbstractType& type_arg,
intptr_t type_param_value_offset_i,
Label* check_failed) {
const Register kInstantiatorTypeArgumentsReg = R1;
const Register kFunctionTypeArgumentsReg = R2;
const Register kInstanceTypeArguments = R7;
const Register kClassIdReg = R9;
const Register kOwnTypeArgumentValue = TMP;
BuildOptimizedTypeArgumentValueCheck(
assembler, hi, type_arg, type_param_value_offset_i, kClassIdReg,
kInstanceTypeArguments, kInstantiatorTypeArgumentsReg,
kFunctionTypeArgumentsReg, kOwnTypeArgumentValue, check_failed);
}
static void InvokeTypeCheckFromTypeTestStub(Assembler* assembler,
TypeCheckMode mode) {
const Register kInstanceReg = R0;
const Register kInstantiatorTypeArgumentsReg = R1;
const Register kFunctionTypeArgumentsReg = R2;
const Register kSubtypeTestCacheReg = R3;
const Register kDstTypeReg = R8;
__ PushObject(Object::null_object()); // Make room for result.
__ Push(kInstanceReg);
__ Push(kDstTypeReg);
__ Push(kInstantiatorTypeArgumentsReg);
__ Push(kFunctionTypeArgumentsReg);
__ PushObject(Object::null_object());
__ Push(kSubtypeTestCacheReg);
__ PushObject(Smi::ZoneHandle(Smi::New(mode)));
__ CallRuntime(kTypeCheckRuntimeEntry, 7);
__ Drop(1); // mode
__ Pop(kSubtypeTestCacheReg);
__ Drop(1); // dst_name
__ Pop(kFunctionTypeArgumentsReg);
__ Pop(kInstantiatorTypeArgumentsReg);
__ Pop(kDstTypeReg);
__ Pop(kInstanceReg);
__ Drop(1); // Discard return value.
}
void StubCode::GenerateLazySpecializeTypeTestStub(Assembler* assembler) {
const Register kInstanceReg = R0;
Label done;
__ CompareObject(kInstanceReg, Object::null_object());
__ BranchIf(EQUAL, &done);
__ ldr(CODE_REG,
Address(THR, Thread::lazy_specialize_type_test_stub_offset()));
__ EnterStubFrame();
InvokeTypeCheckFromTypeTestStub(assembler, kTypeCheckFromLazySpecializeStub);
__ LeaveStubFrame();
__ Bind(&done);
__ Ret();
}
void StubCode::GenerateSlowTypeTestStub(Assembler* assembler) {
Label done, call_runtime;
const Register kInstanceReg = R0;
const Register kInstantiatorTypeArgumentsReg = R1;
const Register kSubtypeTestCacheReg = R3;
const Register kDstTypeReg = R8;
__ EnterStubFrame();
#ifdef DEBUG
// Guaranteed by caller.
Label no_error;
__ CompareObject(kInstanceReg, Object::null_object());
__ BranchIf(NOT_EQUAL, &no_error);
__ Breakpoint();
__ Bind(&no_error);
#endif
// If the subtype-cache is null, it needs to be lazily-created by the runtime.
__ CompareObject(kSubtypeTestCacheReg, Object::null_object());
__ BranchIf(EQUAL, &call_runtime);
const Register kTmp = R9;
// If this is not a [Type] object, we'll go to the runtime.
Label is_simple_case, is_complex_case;
__ LoadClassId(kTmp, kDstTypeReg);
__ cmp(kTmp, Operand(kTypeCid));
__ BranchIf(NOT_EQUAL, &is_complex_case);
// Check whether this [Type] is instantiated/uninstantiated.
__ ldr(kTmp, FieldAddress(kDstTypeReg, Type::type_state_offset()), kByte);
__ cmp(kTmp, Operand(RawType::kFinalizedInstantiated));
__ BranchIf(NOT_EQUAL, &is_complex_case);
// Check whether this [Type] is a function type.
__ ldr(kTmp, FieldAddress(kDstTypeReg, Type::signature_offset()));
__ CompareObject(kTmp, Object::null_object());
__ BranchIf(NOT_EQUAL, &is_complex_case);
// This [Type] could be a FutureOr. Subtype2TestCache does not support Smi.
__ BranchIfSmi(kInstanceReg, &is_complex_case);
// Fall through to &is_simple_case
__ Bind(&is_simple_case);
{
__ PushPair(kInstantiatorTypeArgumentsReg, kSubtypeTestCacheReg);
__ BranchLink(StubCode::Subtype2TestCache());
__ CompareObject(R1, Bool::True());
__ PopPair(kInstantiatorTypeArgumentsReg, kSubtypeTestCacheReg);
__ BranchIf(EQUAL, &done); // Cache said: yes.
__ Jump(&call_runtime);
}
__ Bind(&is_complex_case);
{
__ PushPair(kInstantiatorTypeArgumentsReg, kSubtypeTestCacheReg);
__ BranchLink(StubCode::Subtype6TestCache());
__ CompareObject(R1, Bool::True());
__ PopPair(kInstantiatorTypeArgumentsReg, kSubtypeTestCacheReg);
__ BranchIf(EQUAL, &done); // Cache said: yes.
// Fall through to runtime_call
}
__ Bind(&call_runtime);
// We cannot really ensure here that dynamic/Object/void never occur here
// (though it is guaranteed at dart_precompiled_runtime time). This is
// because we do constant evaluation with default stubs and only install
// optimized versions before writing out the AOT snapshot.
// So dynamic/Object/void will run with default stub in constant evaluation.
__ CompareObject(kDstTypeReg, Type::dynamic_type());
__ BranchIf(EQUAL, &done);
__ CompareObject(kDstTypeReg, Type::Handle(Type::ObjectType()));
__ BranchIf(EQUAL, &done);
__ CompareObject(kDstTypeReg, Type::void_type());
__ BranchIf(EQUAL, &done);
InvokeTypeCheckFromTypeTestStub(assembler, kTypeCheckFromSlowStub);
__ Bind(&done);
__ LeaveStubFrame();
__ Ret();
}
void StubCode::GenerateGetCStackPointerStub(Assembler* assembler) {
__ 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.
void StubCode::GenerateJumpToFrameStub(Assembler* assembler) {
ASSERT(kExceptionObjectReg == R0);
ASSERT(kStackTraceObjectReg == R1);
__ mov(LR, R0); // Program counter.
__ mov(SP, R1); // Stack pointer.
__ mov(FP, R2); // Frame_pointer.
__ mov(THR, R3);
__ ldr(BARRIER_MASK, Address(THR, Thread::write_barrier_mask_offset()));
// Set the tag.
__ LoadImmediate(R2, VMTag::kDartCompiledTagId);
__ StoreToOffset(R2, THR, Thread::vm_tag_offset());
// Clear top exit frame.
__ StoreToOffset(ZR, THR, Thread::top_exit_frame_info_offset());
// Restore the pool pointer.
__ RestoreCodePointer();
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ ldr(PP, Address(THR, Thread::global_object_pool_offset()));
__ sub(PP, PP, Operand(kHeapObjectTag)); // Pool in PP is untagged!
} else {
__ LoadPoolPointer();
}
__ ret(); // 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 StubCode::GenerateRunExceptionHandlerStub(Assembler* assembler) {
__ LoadFromOffset(LR, THR, Thread::resume_pc_offset());
ASSERT(Thread::CanLoadFromThread(Object::null_object()));
__ LoadFromOffset(R2, THR, Thread::OffsetFromThread(Object::null_object()));
// Exception object.
__ LoadFromOffset(R0, THR, Thread::active_exception_offset());
__ StoreToOffset(R2, THR, Thread::active_exception_offset());
// StackTrace object.
__ LoadFromOffset(R1, THR, Thread::active_stacktrace_offset());
__ StoreToOffset(R2, THR, 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 StubCode::GenerateDeoptForRewindStub(Assembler* assembler) {
// Push zap value instead of CODE_REG.
__ LoadImmediate(TMP, kZapCodeReg);
__ Push(TMP);
// Load the deopt pc into LR.
__ LoadFromOffset(LR, THR, 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.
// R4: argument descriptor (preserved).
void StubCode::GenerateOptimizeFunctionStub(Assembler* assembler) {
__ EnterStubFrame();
__ Push(R4);
// Setup space on stack for the return value.
__ Push(ZR);
__ Push(R6);
__ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry, 1);
__ Pop(R0); // Discard argument.
__ Pop(R0); // Get Function object
__ Pop(R4); // Restore argument descriptor.
__ LoadFieldFromOffset(CODE_REG, R0, Function::code_offset());
__ LoadFieldFromOffset(R1, R0, 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.
// Left and right are pushed on stack.
// Return Zero condition flag set if equal.
// Note: A Mint cannot contain a value that would fit in Smi.
static void GenerateIdenticalWithNumberCheckStub(Assembler* assembler,
const Register left,
const Register right) {
Label reference_compare, done, check_mint;
// If any of the arguments is Smi do reference compare.
__ BranchIfSmi(left, &reference_compare);
__ BranchIfSmi(right, &reference_compare);
// Value compare for two doubles.
__ CompareClassId(left, kDoubleCid);
__ b(&check_mint, NE);
__ CompareClassId(right, kDoubleCid);
__ b(&done, NE);
// Double values bitwise compare.
__ LoadFieldFromOffset(left, left, Double::value_offset());
__ LoadFieldFromOffset(right, right, Double::value_offset());
__ b(&reference_compare);
__ Bind(&check_mint);
__ CompareClassId(left, kMintCid);
__ b(&reference_compare, NE);
__ CompareClassId(right, kMintCid);
__ b(&done, NE);
__ LoadFieldFromOffset(left, left, Mint::value_offset());
__ LoadFieldFromOffset(right, right, Mint::value_offset());
__ Bind(&reference_compare);
__ CompareRegisters(left, right);
__ Bind(&done);
}
// 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 StubCode::GenerateUnoptimizedIdenticalWithNumberCheckStub(
Assembler* assembler) {
#if !defined(PRODUCT)
// Check single stepping.
Label stepping, done_stepping;
__ LoadIsolate(R1);
__ LoadFromOffset(R1, R1, 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 * kWordSize);
__ LoadFromOffset(right, SP, 0 * kWordSize);
GenerateIdenticalWithNumberCheckStub(assembler, left, right);
__ ret();
#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 StubCode::GenerateOptimizedIdenticalWithNumberCheckStub(
Assembler* assembler) {
const Register left = R1;
const Register right = R0;
__ LoadFromOffset(left, SP, 1 * kWordSize);
__ LoadFromOffset(right, SP, 0 * kWordSize);
GenerateIdenticalWithNumberCheckStub(assembler, left, right);
__ ret();
}
// Called from megamorphic calls.
// R0: receiver
// R5: MegamorphicCache (preserved)
// Passed to target:
// CODE_REG: target Code
// R4: arguments descriptor
void StubCode::GenerateMegamorphicCallStub(Assembler* assembler) {
// Jump if receiver is a smi.
Label smi_case;
__ BranchIfSmi(R0, &smi_case);
// Loads the cid of the object.
__ LoadClassId(R0, R0);
Label cid_loaded;
__ Bind(&cid_loaded);
__ ldr(R2, FieldAddress(R5, MegamorphicCache::buckets_offset()));
__ ldr(R1, FieldAddress(R5, MegamorphicCache::mask_offset()));
// R2: cache buckets array.
// R1: mask as a smi.
// Make the cid into a smi.
__ SmiTag(R0);
// R0: class ID of the receiver (smi).
// Compute the table index.
ASSERT(MegamorphicCache::kSpreadFactor == 7);
// Use lsl and sub to multiply with 7 == 8 - 1.
__ LslImmediate(R3, R0, 3);
__ sub(R3, R3, Operand(R0));
// R3: probe.
Label loop;
__ Bind(&loop);
__ and_(R3, R3, Operand(R1));
const intptr_t base = Array::data_offset();
// R3 is smi tagged, but table entries are 16 bytes, so LSL 3.
__ add(TMP, R2, Operand(R3, LSL, 3));
__ ldr(R6, FieldAddress(TMP, base));
Label probe_failed;
__ CompareRegisters(R6, R0);
__ 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.
const auto target_address = FieldAddress(TMP, base + kWordSize);
if (FLAG_precompiled_mode && FLAG_use_bare_instructions) {
__ ldr(R1, target_address);
__ ldr(ARGS_DESC_REG,
FieldAddress(R5, MegamorphicCache::arguments_descriptor_offset()));
} else {
__ ldr(R0, target_address);
__ ldr(R1, FieldAddress(R0, Function::entry_point_offset()));
__ ldr(ARGS_DESC_REG,
FieldAddress(R5, MegamorphicCache::arguments_descriptor_offset()));
__ ldr(CODE_REG, FieldAddress(R0, Function::code_offset()));
}
__ br(R1);
// Probe failed, check if it is a miss.
__ Bind(&probe_failed);
ASSERT(kIllegalCid == 0);
__ tst(R6, Operand(R6));
__ b(&load_target, EQ); // branch if miss.
// Try next extry in the table.
__ AddImmediate(R3, Smi::RawValue(1));
__ b(&loop);
// Load cid for the Smi case.
__ Bind(&smi_case);
__ LoadImmediate(R0, kSmiCid);
__ b(&cid_loaded);
}
// Called from switchable IC calls.
// R0: receiver
// R5: ICData (preserved)
// Passed to target:
// CODE_REG: target Code object
// R4: arguments descriptor
void StubCode::GenerateICCallThroughFunctionStub(Assembler* assembler) {
Label loop, found, miss;
__ ldr(ARGS_DESC_REG,
FieldAddress(R5, ICData::arguments_descriptor_offset()));
__ ldr(R8, FieldAddress(R5, ICData::ic_data_offset()));
__ AddImmediate(R8, Array::data_offset() - kHeapObjectTag);
// R8: first IC entry
__ LoadTaggedClassIdMayBeSmi(R1, R0);
// R1: receiver cid as Smi
__ Bind(&loop);
__ ldr(R2, Address(R8, 0));
__ cmp(R1, Operand(R2));
__ b(&found, EQ);
__ CompareImmediate(R2, Smi::RawValue(kIllegalCid));
__ b(&miss, EQ);
const intptr_t entry_length =
ICData::TestEntryLengthFor(1, /*tracking_exactness=*/false) * kWordSize;
__ AddImmediate(R8, entry_length); // Next entry.
__ b(&loop);
__ Bind(&found);
const intptr_t target_offset = ICData::TargetIndexFor(1) * kWordSize;
__ ldr(R0, Address(R8, target_offset));
__ ldr(R1, FieldAddress(R0, Function::entry_point_offset()));
__ ldr(CODE_REG, FieldAddress(R0, Function::code_offset()));
__ br(R1);
__ Bind(&miss);
__ LoadIsolate(R2);
__ ldr(CODE_REG, Address(R2, Isolate::ic_miss_code_offset()));
__ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ br(R1);
}
void StubCode::GenerateICCallThroughCodeStub(Assembler* assembler) {
Label loop, found, miss;
__ ldr(R8, FieldAddress(R5, ICData::ic_data_offset()));
__ ldr(R4, FieldAddress(R5, ICData::arguments_descriptor_offset()));
__ AddImmediate(R8, Array::data_offset() - kHeapObjectTag);
// R8: first IC entry
__ LoadTaggedClassIdMayBeSmi(R1, R0);
// R1: receiver cid as Smi
__ Bind(&loop);
__ ldr(R2, Address(R8, 0));
__ cmp(R1, Operand(R2));
__ b(&found, EQ);
__ CompareImmediate(R2, Smi::RawValue(kIllegalCid));
__ b(&miss, EQ);
const intptr_t entry_length =
ICData::TestEntryLengthFor(1, /*tracking_exactness=*/false) * kWordSize;
__ AddImmediate(R8, entry_length); // Next entry.
__ b(&loop);
__ Bind(&found);
const intptr_t code_offset = ICData::CodeIndexFor(1) * kWordSize;
const intptr_t entry_offset = ICData::EntryPointIndexFor(1) * kWordSize;
__ ldr(R1, Address(R8, entry_offset));
if (!(FLAG_precompiled_mode && FLAG_use_bare_instructions)) {
__ ldr(CODE_REG, Address(R8, code_offset));
}
__ br(R1);
__ Bind(&miss);
__ LoadIsolate(R2);
__ ldr(CODE_REG, Address(R2, Isolate::ic_miss_code_offset()));
__ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset()));
__ br(R1);
}
// Called from switchable IC calls.
// R0: receiver
// R5: SingleTargetCache
void StubCode::GenerateUnlinkedCallStub(Assembler* assembler) {
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(ZR); // Result slot.
__ Push(R0); // Arg0: Receiver
__ Push(R5); // Arg1: UnlinkedCall
__ CallRuntime(kUnlinkedCallRuntimeEntry, 2);
__ Drop(2);
__ Pop(R5); // result = IC
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ ldr(CODE_REG, Address(THR, Thread::ic_lookup_through_code_stub_offset()));
__ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset(
Code::EntryKind::kMonomorphic)));
__ br(R1);
}
// Called from switchable IC calls.
// R0: receiver
// R5: SingleTargetCache
// Passed to target:
// CODE_REG: target Code object
void StubCode::GenerateSingleTargetCallStub(Assembler* assembler) {
Label miss;
__ LoadClassIdMayBeSmi(R1, R0);
__ ldr(R2, FieldAddress(R5, SingleTargetCache::lower_limit_offset()),
kUnsignedHalfword);
__ ldr(R3, FieldAddress(R5, SingleTargetCache::upper_limit_offset()),
kUnsignedHalfword);
__ cmp(R1, Operand(R2));
__ b(&miss, LT);
__ cmp(R1, Operand(R3));
__ b(&miss, GT);
__ ldr(R1, FieldAddress(R5, SingleTargetCache::entry_point_offset()));
__ ldr(CODE_REG, FieldAddress(R5, SingleTargetCache::target_offset()));
__ br(R1);
__ Bind(&miss);
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(ZR); // Result slot.
__ Push(R0); // Arg0: Receiver
__ CallRuntime(kSingleTargetMissRuntimeEntry, 1);
__ Drop(1);
__ Pop(R5); // result = IC
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ ldr(CODE_REG, Address(THR, Thread::ic_lookup_through_code_stub_offset()));
__ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset(
Code::EntryKind::kMonomorphic)));
__ br(R1);
}
// Called from the monomorphic checked entry.
// R0: receiver
void StubCode::GenerateMonomorphicMissStub(Assembler* assembler) {
__ ldr(CODE_REG, Address(THR, Thread::monomorphic_miss_stub_offset()));
__ EnterStubFrame();
__ Push(R0); // Preserve receiver.
__ Push(ZR); // Result slot.
__ Push(R0); // Arg0: Receiver
__ CallRuntime(kMonomorphicMissRuntimeEntry, 1);
__ Drop(1);
__ Pop(R5); // result = IC
__ Pop(R0); // Restore receiver.
__ LeaveStubFrame();
__ ldr(CODE_REG, Address(THR, Thread::ic_lookup_through_code_stub_offset()));
__ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset(
Code::EntryKind::kMonomorphic)));
__ br(R1);
}
void StubCode::GenerateFrameAwaitingMaterializationStub(Assembler* assembler) {
__ brk(0);
}
void StubCode::GenerateAsynchronousGapMarkerStub(Assembler* assembler) {
__ brk(0);
}
} // namespace dart
#endif // defined(TARGET_ARCH_ARM64) && !defined(DART_PRECOMPILED_RUNTIME)
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