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dart / sdk.git / 76ec69ee27be5d921c03404afece188a52c0ab42 / . / runtime / vm / compiler / assembler / assembler_arm64.cc
blob: 305b3a949ff449263b76960d378f03e41eaee8a6 [file] [log] [blame]
// 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" // NOLINT
#if defined(TARGET_ARCH_ARM64) && !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/compiler/assembler/assembler.h"
#include "vm/cpu.h"
#include "vm/longjump.h"
#include "vm/runtime_entry.h"
#include "vm/simulator.h"
#include "vm/stack_frame.h"
#include "vm/stub_code.h"
namespace dart {
DECLARE_FLAG(bool, check_code_pointer);
DECLARE_FLAG(bool, inline_alloc);
DEFINE_FLAG(bool, use_far_branches, false, "Always use far branches");
Assembler::Assembler(bool use_far_branches)
: buffer_(),
prologue_offset_(-1),
has_single_entry_point_(true),
use_far_branches_(use_far_branches),
comments_(),
constant_pool_allowed_(false) {}
void Assembler::InitializeMemoryWithBreakpoints(uword data, intptr_t length) {
ASSERT(Utils::IsAligned(data, 4));
ASSERT(Utils::IsAligned(length, 4));
const uword end = data + length;
while (data < end) {
*reinterpret_cast<int32_t*>(data) = Instr::kBreakPointInstruction;
data += 4;
}
}
void Assembler::Emit(int32_t value) {
AssemblerBuffer::EnsureCapacity ensured(&buffer_);
buffer_.Emit<int32_t>(value);
}
static const char* cpu_reg_names[kNumberOfCpuRegisters] = {
"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
"r11", "r12", "r13", "r14", "r15", "r16", "r17", "r18", "r19", "r20", "r21",
"r22", "r23", "r24", "ip0", "ip1", "pp", "ctx", "fp", "lr", "r31",
};
const char* Assembler::RegisterName(Register reg) {
ASSERT((0 <= reg) && (reg < kNumberOfCpuRegisters));
return cpu_reg_names[reg];
}
static const char* fpu_reg_names[kNumberOfFpuRegisters] = {
"v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8", "v9", "v10",
"v11", "v12", "v13", "v14", "v15", "v16", "v17", "v18", "v19", "v20", "v21",
"v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31",
};
const char* Assembler::FpuRegisterName(FpuRegister reg) {
ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
return fpu_reg_names[reg];
}
int32_t Assembler::BindImm19Branch(int64_t position, int64_t dest) {
if (use_far_branches() && !CanEncodeImm19BranchOffset(dest)) {
// Far branches are enabled, and we can't encode the branch offset in
// 19 bits.
// Grab the guarding branch instruction.
const int32_t guard_branch =
buffer_.Load<int32_t>(position + 0 * Instr::kInstrSize);
// Grab the far branch instruction.
const int32_t far_branch =
buffer_.Load<int32_t>(position + 1 * Instr::kInstrSize);
const Condition c = DecodeImm19BranchCondition(guard_branch);
// Grab the link to the next branch.
const int32_t next = DecodeImm26BranchOffset(far_branch);
// dest is the offset is from the guarding branch instruction.
// Correct it to be from the following instruction.
const int64_t offset = dest - Instr::kInstrSize;
// Encode the branch.
const int32_t encoded_branch = EncodeImm26BranchOffset(offset, far_branch);
// If the guard branch is conditioned on NV, replace it with a nop.
if (c == NV) {
buffer_.Store<int32_t>(position + 0 * Instr::kInstrSize,
Instr::kNopInstruction);
}
// Write the far branch into the buffer and link to the next branch.
buffer_.Store<int32_t>(position + 1 * Instr::kInstrSize, encoded_branch);
return next;
} else if (use_far_branches() && CanEncodeImm19BranchOffset(dest)) {
// We assembled a far branch, but we don't need it. Replace it with a near
// branch.
// Grab the guarding branch instruction.
const int32_t guard_branch =
buffer_.Load<int32_t>(position + 0 * Instr::kInstrSize);
// Grab the far branch instruction.
const int32_t far_branch =
buffer_.Load<int32_t>(position + 1 * Instr::kInstrSize);
// Grab the link to the next branch.
const int32_t next = DecodeImm26BranchOffset(far_branch);
// Re-target the guarding branch and flip the conditional sense.
int32_t encoded_guard_branch = EncodeImm19BranchOffset(dest, guard_branch);
const Condition c = DecodeImm19BranchCondition(encoded_guard_branch);
encoded_guard_branch =
EncodeImm19BranchCondition(InvertCondition(c), encoded_guard_branch);
// Write back the re-encoded instructions. The far branch becomes a nop.
buffer_.Store<int32_t>(position + 0 * Instr::kInstrSize,
encoded_guard_branch);
buffer_.Store<int32_t>(position + 1 * Instr::kInstrSize,
Instr::kNopInstruction);
return next;
} else {
const int32_t next = buffer_.Load<int32_t>(position);
const int32_t encoded = EncodeImm19BranchOffset(dest, next);
buffer_.Store<int32_t>(position, encoded);
return DecodeImm19BranchOffset(next);
}
}
int32_t Assembler::BindImm14Branch(int64_t position, int64_t dest) {
if (use_far_branches() && !CanEncodeImm14BranchOffset(dest)) {
// Far branches are enabled, and we can't encode the branch offset in
// 14 bits.
// Grab the guarding branch instruction.
const int32_t guard_branch =
buffer_.Load<int32_t>(position + 0 * Instr::kInstrSize);
// Grab the far branch instruction.
const int32_t far_branch =
buffer_.Load<int32_t>(position + 1 * Instr::kInstrSize);
const Condition c = DecodeImm14BranchCondition(guard_branch);
// Grab the link to the next branch.
const int32_t next = DecodeImm26BranchOffset(far_branch);
// dest is the offset is from the guarding branch instruction.
// Correct it to be from the following instruction.
const int64_t offset = dest - Instr::kInstrSize;
// Encode the branch.
const int32_t encoded_branch = EncodeImm26BranchOffset(offset, far_branch);
// If the guard branch is conditioned on NV, replace it with a nop.
if (c == NV) {
buffer_.Store<int32_t>(position + 0 * Instr::kInstrSize,
Instr::kNopInstruction);
}
// Write the far branch into the buffer and link to the next branch.
buffer_.Store<int32_t>(position + 1 * Instr::kInstrSize, encoded_branch);
return next;
} else if (use_far_branches() && CanEncodeImm14BranchOffset(dest)) {
// We assembled a far branch, but we don't need it. Replace it with a near
// branch.
// Grab the guarding branch instruction.
const int32_t guard_branch =
buffer_.Load<int32_t>(position + 0 * Instr::kInstrSize);
// Grab the far branch instruction.
const int32_t far_branch =
buffer_.Load<int32_t>(position + 1 * Instr::kInstrSize);
// Grab the link to the next branch.
const int32_t next = DecodeImm26BranchOffset(far_branch);
// Re-target the guarding branch and flip the conditional sense.
int32_t encoded_guard_branch = EncodeImm14BranchOffset(dest, guard_branch);
const Condition c = DecodeImm14BranchCondition(encoded_guard_branch);
encoded_guard_branch =
EncodeImm14BranchCondition(InvertCondition(c), encoded_guard_branch);
// Write back the re-encoded instructions. The far branch becomes a nop.
buffer_.Store<int32_t>(position + 0 * Instr::kInstrSize,
encoded_guard_branch);
buffer_.Store<int32_t>(position + 1 * Instr::kInstrSize,
Instr::kNopInstruction);
return next;
} else {
const int32_t next = buffer_.Load<int32_t>(position);
const int32_t encoded = EncodeImm14BranchOffset(dest, next);
buffer_.Store<int32_t>(position, encoded);
return DecodeImm14BranchOffset(next);
}
}
void Assembler::Bind(Label* label) {
ASSERT(!label->IsBound());
const intptr_t bound_pc = buffer_.Size();
while (label->IsLinked()) {
const int64_t position = label->Position();
const int64_t dest = bound_pc - position;
if (IsTestAndBranch(buffer_.Load<int32_t>(position))) {
label->position_ = BindImm14Branch(position, dest);
} else {
label->position_ = BindImm19Branch(position, dest);
}
}
label->BindTo(bound_pc);
}
void Assembler::Stop(const char* message) {
if (FLAG_print_stop_message) {
UNIMPLEMENTED();
}
brk(Instr::kStopMessageCode);
}
static int CountLeadingZeros(uint64_t value, int width) {
ASSERT((width == 32) || (width == 64));
if (value == 0) {
return width;
}
int count = 0;
do {
count++;
} while (value >>= 1);
return width - count;
}
static int CountOneBits(uint64_t value, int width) {
// Mask out unused bits to ensure that they are not counted.
value &= (0xffffffffffffffffULL >> (64 - width));
value = ((value >> 1) & 0x5555555555555555) + (value & 0x5555555555555555);
value = ((value >> 2) & 0x3333333333333333) + (value & 0x3333333333333333);
value = ((value >> 4) & 0x0f0f0f0f0f0f0f0f) + (value & 0x0f0f0f0f0f0f0f0f);
value = ((value >> 8) & 0x00ff00ff00ff00ff) + (value & 0x00ff00ff00ff00ff);
value = ((value >> 16) & 0x0000ffff0000ffff) + (value & 0x0000ffff0000ffff);
value = ((value >> 32) & 0x00000000ffffffff) + (value & 0x00000000ffffffff);
return value;
}
// Test if a given value can be encoded in the immediate field of a logical
// instruction.
// If it can be encoded, the function returns true, and values pointed to by n,
// imm_s and imm_r are updated with immediates encoded in the format required
// by the corresponding fields in the logical instruction.
// If it can't be encoded, the function returns false, and the operand is
// undefined.
bool Operand::IsImmLogical(uint64_t value, uint8_t width, Operand* imm_op) {
ASSERT(imm_op != NULL);
ASSERT((width == kWRegSizeInBits) || (width == kXRegSizeInBits));
ASSERT((width == kXRegSizeInBits) || (value <= 0xffffffffUL));
uint8_t n = 0;
uint8_t imm_s = 0;
uint8_t imm_r = 0;
// Logical immediates are encoded using parameters n, imm_s and imm_r using
// the following table:
//
// N imms immr size S R
// 1 ssssss rrrrrr 64 UInt(ssssss) UInt(rrrrrr)
// 0 0sssss xrrrrr 32 UInt(sssss) UInt(rrrrr)
// 0 10ssss xxrrrr 16 UInt(ssss) UInt(rrrr)
// 0 110sss xxxrrr 8 UInt(sss) UInt(rrr)
// 0 1110ss xxxxrr 4 UInt(ss) UInt(rr)
// 0 11110s xxxxxr 2 UInt(s) UInt(r)
// (s bits must not be all set)
//
// A pattern is constructed of size bits, where the least significant S+1
// bits are set. The pattern is rotated right by R, and repeated across a
// 32 or 64-bit value, depending on destination register width.
//
// To test if an arbitrary immediate can be encoded using this scheme, an
// iterative algorithm is used.
// 1. If the value has all set or all clear bits, it can't be encoded.
if ((value == 0) || (value == 0xffffffffffffffffULL) ||
((width == kWRegSizeInBits) && (value == 0xffffffff))) {
return false;
}
int lead_zero = CountLeadingZeros(value, width);
int lead_one = CountLeadingZeros(~value, width);
int trail_zero = Utils::CountTrailingZeros(value);
int trail_one = Utils::CountTrailingZeros(~value);
int set_bits = CountOneBits(value, width);
// The fixed bits in the immediate s field.
// If width == 64 (X reg), start at 0xFFFFFF80.
// If width == 32 (W reg), start at 0xFFFFFFC0, as the iteration for 64-bit
// widths won't be executed.
int imm_s_fixed = (width == kXRegSizeInBits) ? -128 : -64;
int imm_s_mask = 0x3F;
for (;;) {
// 2. If the value is two bits wide, it can be encoded.
if (width == 2) {
n = 0;
imm_s = 0x3C;
imm_r = (value & 3) - 1;
*imm_op = Operand(n, imm_s, imm_r);
return true;
}
n = (width == 64) ? 1 : 0;
imm_s = ((imm_s_fixed | (set_bits - 1)) & imm_s_mask);
if ((lead_zero + set_bits) == width) {
imm_r = 0;
} else {
imm_r = (lead_zero > 0) ? (width - trail_zero) : lead_one;
}
// 3. If the sum of leading zeros, trailing zeros and set bits is equal to
// the bit width of the value, it can be encoded.
if (lead_zero + trail_zero + set_bits == width) {
*imm_op = Operand(n, imm_s, imm_r);
return true;
}
// 4. If the sum of leading ones, trailing ones and unset bits in the
// value is equal to the bit width of the value, it can be encoded.
if (lead_one + trail_one + (width - set_bits) == width) {
*imm_op = Operand(n, imm_s, imm_r);
return true;
}
// 5. If the most-significant half of the bitwise value is equal to the
// least-significant half, return to step 2 using the least-significant
// half of the value.
uint64_t mask = (1ULL << (width >> 1)) - 1;
if ((value & mask) == ((value >> (width >> 1)) & mask)) {
width >>= 1;
set_bits >>= 1;
imm_s_fixed >>= 1;
continue;
}
// 6. Otherwise, the value can't be encoded.
return false;
}
}
void Assembler::LoadPoolPointer(Register pp) {
CheckCodePointer();
ldr(pp, FieldAddress(CODE_REG, Code::object_pool_offset()));
// When in the PP register, the pool pointer is untagged. When we
// push it on the stack with TagAndPushPP it is tagged again. PopAndUntagPP
// then untags when restoring from the stack. This will make loading from the
// object pool only one instruction for the first 4096 entries. Otherwise,
// because the offset wouldn't be aligned, it would be only one instruction
// for the first 64 entries.
sub(pp, pp, Operand(kHeapObjectTag));
set_constant_pool_allowed(pp == PP);
}
void Assembler::LoadWordFromPoolOffset(Register dst,
uint32_t offset,
Register pp) {
ASSERT((pp != PP) || constant_pool_allowed());
ASSERT(dst != pp);
Operand op;
const uint32_t upper20 = offset & 0xfffff000;
if (Address::CanHoldOffset(offset)) {
ldr(dst, Address(pp, offset));
} else if (Operand::CanHold(upper20, kXRegSizeInBits, &op) ==
Operand::Immediate) {
const uint32_t lower12 = offset & 0x00000fff;
ASSERT(Address::CanHoldOffset(lower12));
add(dst, pp, op);
ldr(dst, Address(dst, lower12));
} else {
const uint16_t offset_low = Utils::Low16Bits(offset);
const uint16_t offset_high = Utils::High16Bits(offset);
movz(dst, Immediate(offset_low), 0);
if (offset_high != 0) {
movk(dst, Immediate(offset_high), 1);
}
ldr(dst, Address(pp, dst));
}
}
void Assembler::LoadWordFromPoolOffsetFixed(Register dst, uint32_t offset) {
ASSERT(constant_pool_allowed());
ASSERT(dst != PP);
Operand op;
const uint32_t upper20 = offset & 0xfffff000;
const uint32_t lower12 = offset & 0x00000fff;
const Operand::OperandType ot =
Operand::CanHold(upper20, kXRegSizeInBits, &op);
ASSERT(ot == Operand::Immediate);
ASSERT(Address::CanHoldOffset(lower12));
add(dst, PP, op);
ldr(dst, Address(dst, lower12));
}
intptr_t Assembler::FindImmediate(int64_t imm) {
return object_pool_wrapper_.FindImmediate(imm);
}
bool Assembler::CanLoadFromObjectPool(const Object& object) const {
ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
ASSERT(!Thread::CanLoadFromThread(object));
if (!constant_pool_allowed()) {
return false;
}
// TODO(zra, kmillikin): Also load other large immediates from the object
// pool
if (object.IsSmi()) {
ASSERT(Smi::IsValid(Smi::Value(reinterpret_cast<RawSmi*>(object.raw()))));
// If the raw smi does not fit into a 32-bit signed int, then we'll keep
// the raw value in the object pool.
return !Utils::IsInt(32, reinterpret_cast<int64_t>(object.raw()));
}
ASSERT(object.IsNotTemporaryScopedHandle());
ASSERT(object.IsOld());
return true;
}
void Assembler::LoadNativeEntry(Register dst, const ExternalLabel* label) {
const int32_t offset = ObjectPool::element_offset(
object_pool_wrapper_.FindNativeFunction(label, kNotPatchable));
LoadWordFromPoolOffset(dst, offset);
}
void Assembler::LoadIsolate(Register dst) {
ldr(dst, Address(THR, Thread::isolate_offset()));
}
void Assembler::LoadObjectHelper(Register dst,
const Object& object,
bool is_unique) {
ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
if (Thread::CanLoadFromThread(object)) {
ldr(dst, Address(THR, Thread::OffsetFromThread(object)));
} else if (CanLoadFromObjectPool(object)) {
const int32_t offset = ObjectPool::element_offset(
is_unique ? object_pool_wrapper_.AddObject(object)
: object_pool_wrapper_.FindObject(object));
LoadWordFromPoolOffset(dst, offset);
} else {
ASSERT(object.IsSmi());
LoadDecodableImmediate(dst, reinterpret_cast<int64_t>(object.raw()));
}
}
void Assembler::LoadFunctionFromCalleePool(Register dst,
const Function& function,
Register new_pp) {
ASSERT(!constant_pool_allowed());
ASSERT(new_pp != PP);
const int32_t offset =
ObjectPool::element_offset(object_pool_wrapper_.FindObject(function));
ASSERT(Address::CanHoldOffset(offset));
ldr(dst, Address(new_pp, offset));
}
void Assembler::LoadObject(Register dst, const Object& object) {
LoadObjectHelper(dst, object, false);
}
void Assembler::LoadUniqueObject(Register dst, const Object& object) {
LoadObjectHelper(dst, object, true);
}
void Assembler::CompareObject(Register reg, const Object& object) {
ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
if (Thread::CanLoadFromThread(object)) {
ldr(TMP, Address(THR, Thread::OffsetFromThread(object)));
CompareRegisters(reg, TMP);
} else if (CanLoadFromObjectPool(object)) {
LoadObject(TMP, object);
CompareRegisters(reg, TMP);
} else {
ASSERT(object.IsSmi());
CompareImmediate(reg, reinterpret_cast<int64_t>(object.raw()));
}
}
void Assembler::LoadDecodableImmediate(Register reg, int64_t imm) {
if (constant_pool_allowed()) {
const int32_t offset = ObjectPool::element_offset(FindImmediate(imm));
LoadWordFromPoolOffset(reg, offset);
} else {
// TODO(zra): Since this sequence only needs to be decodable, it can be
// of variable length.
LoadImmediateFixed(reg, imm);
}
}
void Assembler::LoadImmediateFixed(Register reg, int64_t imm) {
const uint32_t w0 = Utils::Low32Bits(imm);
const uint32_t w1 = Utils::High32Bits(imm);
const uint16_t h0 = Utils::Low16Bits(w0);
const uint16_t h1 = Utils::High16Bits(w0);
const uint16_t h2 = Utils::Low16Bits(w1);
const uint16_t h3 = Utils::High16Bits(w1);
movz(reg, Immediate(h0), 0);
movk(reg, Immediate(h1), 1);
movk(reg, Immediate(h2), 2);
movk(reg, Immediate(h3), 3);
}
void Assembler::LoadImmediate(Register reg, int64_t imm) {
Comment("LoadImmediate");
// Is it 0?
if (imm == 0) {
movz(reg, Immediate(0), 0);
return;
}
// Can we use one orri operation?
Operand op;
Operand::OperandType ot;
ot = Operand::CanHold(imm, kXRegSizeInBits, &op);
if (ot == Operand::BitfieldImm) {
orri(reg, ZR, Immediate(imm));
return;
}
// We may fall back on movz, movk, movn.
const uint32_t w0 = Utils::Low32Bits(imm);
const uint32_t w1 = Utils::High32Bits(imm);
const uint16_t h0 = Utils::Low16Bits(w0);
const uint16_t h1 = Utils::High16Bits(w0);
const uint16_t h2 = Utils::Low16Bits(w1);
const uint16_t h3 = Utils::High16Bits(w1);
// Special case for w1 == 0xffffffff
if (w1 == 0xffffffff) {
if (h1 == 0xffff) {
movn(reg, Immediate(~h0), 0);
} else {
movn(reg, Immediate(~h1), 1);
movk(reg, Immediate(h0), 0);
}
return;
}
// Special case for h3 == 0xffff
if (h3 == 0xffff) {
// We know h2 != 0xffff.
movn(reg, Immediate(~h2), 2);
if (h1 != 0xffff) {
movk(reg, Immediate(h1), 1);
}
if (h0 != 0xffff) {
movk(reg, Immediate(h0), 0);
}
return;
}
// Use constant pool if allowed, unless we can load imm with 2 instructions.
if ((w1 != 0) && constant_pool_allowed()) {
const int32_t offset = ObjectPool::element_offset(FindImmediate(imm));
LoadWordFromPoolOffset(reg, offset);
return;
}
bool initialized = false;
if (h0 != 0) {
movz(reg, Immediate(h0), 0);
initialized = true;
}
if (h1 != 0) {
if (initialized) {
movk(reg, Immediate(h1), 1);
} else {
movz(reg, Immediate(h1), 1);
initialized = true;
}
}
if (h2 != 0) {
if (initialized) {
movk(reg, Immediate(h2), 2);
} else {
movz(reg, Immediate(h2), 2);
initialized = true;
}
}
if (h3 != 0) {
if (initialized) {
movk(reg, Immediate(h3), 3);
} else {
movz(reg, Immediate(h3), 3);
}
}
}
void Assembler::LoadDImmediate(VRegister vd, double immd) {
if (!fmovdi(vd, immd)) {
int64_t imm = bit_cast<int64_t, double>(immd);
LoadImmediate(TMP, imm);
fmovdr(vd, TMP);
}
}
void Assembler::Branch(const StubEntry& stub_entry,
Register pp,
Patchability patchable) {
const Code& target = Code::ZoneHandle(stub_entry.code());
const int32_t offset = ObjectPool::element_offset(
object_pool_wrapper_.FindObject(target, patchable));
LoadWordFromPoolOffset(CODE_REG, offset, pp);
ldr(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
br(TMP);
}
void Assembler::BranchPatchable(const StubEntry& stub_entry) {
Branch(stub_entry, PP, kPatchable);
}
void Assembler::BranchLink(const StubEntry& stub_entry,
Patchability patchable) {
const Code& target = Code::ZoneHandle(stub_entry.code());
const int32_t offset = ObjectPool::element_offset(
object_pool_wrapper_.FindObject(target, patchable));
LoadWordFromPoolOffset(CODE_REG, offset);
ldr(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
blr(TMP);
}
void Assembler::BranchLinkPatchable(const StubEntry& stub_entry) {
BranchLink(stub_entry, kPatchable);
}
void Assembler::BranchLinkToRuntime() {
ldr(LR, Address(THR, Thread::call_to_runtime_entry_point_offset()));
ldr(CODE_REG, Address(THR, Thread::call_to_runtime_stub_offset()));
blr(LR);
}
void Assembler::BranchLinkWithEquivalence(const StubEntry& stub_entry,
const Object& equivalence) {
const Code& target = Code::ZoneHandle(stub_entry.code());
const int32_t offset = ObjectPool::element_offset(
object_pool_wrapper_.FindObject(target, equivalence));
LoadWordFromPoolOffset(CODE_REG, offset);
ldr(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
blr(TMP);
}
void Assembler::AddImmediate(Register dest, Register rn, int64_t imm) {
Operand op;
if (imm == 0) {
if (dest != rn) {
mov(dest, rn);
}
return;
}
if (Operand::CanHold(imm, kXRegSizeInBits, &op) == Operand::Immediate) {
add(dest, rn, op);
} else if (Operand::CanHold(-imm, kXRegSizeInBits, &op) ==
Operand::Immediate) {
sub(dest, rn, op);
} else {
// TODO(zra): Try adding top 12 bits, then bottom 12 bits.
ASSERT(rn != TMP2);
LoadImmediate(TMP2, imm);
add(dest, rn, Operand(TMP2));
}
}
void Assembler::AddImmediateSetFlags(Register dest,
Register rn,
int64_t imm,
OperandSize sz) {
ASSERT(sz == kDoubleWord || sz == kWord);
Operand op;
if (Operand::CanHold(imm, kXRegSizeInBits, &op) == Operand::Immediate) {
// Handles imm == kMinInt64.
if (sz == kDoubleWord) {
adds(dest, rn, op);
} else {
addsw(dest, rn, op);
}
} else if (Operand::CanHold(-imm, kXRegSizeInBits, &op) ==
Operand::Immediate) {
ASSERT(imm != kMinInt64); // Would cause erroneous overflow detection.
if (sz == kDoubleWord) {
subs(dest, rn, op);
} else {
subsw(dest, rn, op);
}
} else {
// TODO(zra): Try adding top 12 bits, then bottom 12 bits.
ASSERT(rn != TMP2);
LoadImmediate(TMP2, imm);
if (sz == kDoubleWord) {
adds(dest, rn, Operand(TMP2));
} else {
addsw(dest, rn, Operand(TMP2));
}
}
}
void Assembler::SubImmediateSetFlags(Register dest,
Register rn,
int64_t imm,
OperandSize sz) {
Operand op;
ASSERT(sz == kDoubleWord || sz == kWord);
if (Operand::CanHold(imm, kXRegSizeInBits, &op) == Operand::Immediate) {
// Handles imm == kMinInt64.
if (sz == kDoubleWord) {
subs(dest, rn, op);
} else {
subsw(dest, rn, op);
}
} else if (Operand::CanHold(-imm, kXRegSizeInBits, &op) ==
Operand::Immediate) {
ASSERT(imm != kMinInt64); // Would cause erroneous overflow detection.
if (sz == kDoubleWord) {
adds(dest, rn, op);
} else {
addsw(dest, rn, op);
}
} else {
// TODO(zra): Try subtracting top 12 bits, then bottom 12 bits.
ASSERT(rn != TMP2);
LoadImmediate(TMP2, imm);
if (sz == kDoubleWord) {
subs(dest, rn, Operand(TMP2));
} else {
subsw(dest, rn, Operand(TMP2));
}
}
}
void Assembler::AndImmediate(Register rd, Register rn, int64_t imm) {
Operand imm_op;
if (Operand::IsImmLogical(imm, kXRegSizeInBits, &imm_op)) {
andi(rd, rn, Immediate(imm));
} else {
LoadImmediate(TMP, imm);
and_(rd, rn, Operand(TMP));
}
}
void Assembler::OrImmediate(Register rd, Register rn, int64_t imm) {
Operand imm_op;
if (Operand::IsImmLogical(imm, kXRegSizeInBits, &imm_op)) {
orri(rd, rn, Immediate(imm));
} else {
LoadImmediate(TMP, imm);
orr(rd, rn, Operand(TMP));
}
}
void Assembler::XorImmediate(Register rd, Register rn, int64_t imm) {
Operand imm_op;
if (Operand::IsImmLogical(imm, kXRegSizeInBits, &imm_op)) {
eori(rd, rn, Immediate(imm));
} else {
LoadImmediate(TMP, imm);
eor(rd, rn, Operand(TMP));
}
}
void Assembler::TestImmediate(Register rn, int64_t imm) {
Operand imm_op;
if (Operand::IsImmLogical(imm, kXRegSizeInBits, &imm_op)) {
tsti(rn, Immediate(imm));
} else {
LoadImmediate(TMP, imm);
tst(rn, Operand(TMP));
}
}
void Assembler::CompareImmediate(Register rn, int64_t imm) {
Operand op;
if (Operand::CanHold(imm, kXRegSizeInBits, &op) == Operand::Immediate) {
cmp(rn, op);
} else if (Operand::CanHold(-imm, kXRegSizeInBits, &op) ==
Operand::Immediate) {
cmn(rn, op);
} else {
ASSERT(rn != TMP2);
LoadImmediate(TMP2, imm);
cmp(rn, Operand(TMP2));
}
}
void Assembler::LoadFromOffset(Register dest,
Register base,
int32_t offset,
OperandSize sz) {
if (Address::CanHoldOffset(offset, Address::Offset, sz)) {
ldr(dest, Address(base, offset, Address::Offset, sz), sz);
} else {
ASSERT(base != TMP2);
AddImmediate(TMP2, base, offset);
ldr(dest, Address(TMP2), sz);
}
}
void Assembler::LoadDFromOffset(VRegister dest, Register base, int32_t offset) {
if (Address::CanHoldOffset(offset, Address::Offset, kDWord)) {
fldrd(dest, Address(base, offset, Address::Offset, kDWord));
} else {
ASSERT(base != TMP2);
AddImmediate(TMP2, base, offset);
fldrd(dest, Address(TMP2));
}
}
void Assembler::LoadQFromOffset(VRegister dest, Register base, int32_t offset) {
if (Address::CanHoldOffset(offset, Address::Offset, kQWord)) {
fldrq(dest, Address(base, offset, Address::Offset, kQWord));
} else {
ASSERT(base != TMP2);
AddImmediate(TMP2, base, offset);
fldrq(dest, Address(TMP2));
}
}
void Assembler::StoreToOffset(Register src,
Register base,
int32_t offset,
OperandSize sz) {
ASSERT(base != TMP2);
if (Address::CanHoldOffset(offset, Address::Offset, sz)) {
str(src, Address(base, offset, Address::Offset, sz), sz);
} else {
ASSERT(src != TMP2);
AddImmediate(TMP2, base, offset);
str(src, Address(TMP2), sz);
}
}
void Assembler::StoreDToOffset(VRegister src, Register base, int32_t offset) {
if (Address::CanHoldOffset(offset, Address::Offset, kDWord)) {
fstrd(src, Address(base, offset, Address::Offset, kDWord));
} else {
ASSERT(base != TMP2);
AddImmediate(TMP2, base, offset);
fstrd(src, Address(TMP2));
}
}
void Assembler::StoreQToOffset(VRegister src, Register base, int32_t offset) {
if (Address::CanHoldOffset(offset, Address::Offset, kQWord)) {
fstrq(src, Address(base, offset, Address::Offset, kQWord));
} else {
ASSERT(base != TMP2);
AddImmediate(TMP2, base, offset);
fstrq(src, Address(TMP2));
}
}
void Assembler::VRecps(VRegister vd, VRegister vn) {
ASSERT(vn != VTMP);
ASSERT(vd != VTMP);
// Reciprocal estimate.
vrecpes(vd, vn);
// 2 Newton-Raphson steps.
vrecpss(VTMP, vn, vd);
vmuls(vd, vd, VTMP);
vrecpss(VTMP, vn, vd);
vmuls(vd, vd, VTMP);
}
void Assembler::VRSqrts(VRegister vd, VRegister vn) {
ASSERT(vd != VTMP);
ASSERT(vn != VTMP);
// Reciprocal square root estimate.
vrsqrtes(vd, vn);
// 2 Newton-Raphson steps. xn+1 = xn * (3 - V1*xn^2) / 2.
// First step.
vmuls(VTMP, vd, vd); // VTMP <- xn^2
vrsqrtss(VTMP, vn, VTMP); // VTMP <- (3 - V1*VTMP) / 2.
vmuls(vd, vd, VTMP); // xn+1 <- xn * VTMP
// Second step.
vmuls(VTMP, vd, vd);
vrsqrtss(VTMP, vn, VTMP);
vmuls(vd, vd, VTMP);
}
// Preserves object and value registers.
void Assembler::StoreIntoObjectFilter(Register object,
Register value,
Label* label,
CanBeSmi value_can_be_smi,
BarrierFilterMode how_to_jump) {
COMPILE_ASSERT((kNewObjectAlignmentOffset == kWordSize) &&
(kOldObjectAlignmentOffset == 0));
// Write-barrier triggers if the value is in the new space (has bit set) and
// the object is in the old space (has bit cleared).
if (value_can_be_smi == kValueIsNotSmi) {
// To check that, we compute value & ~object and skip the write barrier
// if the bit is not set. We can't destroy the object.
bic(TMP, value, Operand(object));
} else {
// For the value we are only interested in the new/old bit and the tag bit.
// And the new bit with the tag bit. The resulting bit will be 0 for a Smi.
and_(TMP, value, Operand(value, LSL, kNewObjectBitPosition));
// And the result with the negated space bit of the object.
bic(TMP, TMP, Operand(object));
}
if (how_to_jump == kJumpToNoUpdate) {
tbz(label, TMP, kNewObjectBitPosition);
} else {
tbnz(label, TMP, kNewObjectBitPosition);
}
}
void Assembler::StoreIntoObjectOffset(Register object,
int32_t offset,
Register value,
CanBeSmi value_can_be_smi) {
if (Address::CanHoldOffset(offset - kHeapObjectTag)) {
StoreIntoObject(object, FieldAddress(object, offset), value,
value_can_be_smi);
} else {
AddImmediate(TMP, object, offset - kHeapObjectTag);
StoreIntoObject(object, Address(TMP), value, value_can_be_smi);
}
}
void Assembler::StoreIntoObject(Register object,
const Address& dest,
Register value,
CanBeSmi can_be_smi) {
ASSERT(object != value);
str(value, dest);
Label done;
StoreIntoObjectFilter(object, value, &done, kValueCanBeSmi, kJumpToNoUpdate);
// A store buffer update is required.
if (value != R0) {
// Preserve R0.
Push(R0);
}
Push(LR);
if (object != R0) {
mov(R0, object);
}
ldr(TMP, Address(THR, Thread::update_store_buffer_entry_point_offset()));
ldr(CODE_REG, Address(THR, Thread::update_store_buffer_code_offset()));
blr(TMP);
Pop(LR);
if (value != R0) {
// Restore R0.
Pop(R0);
}
Bind(&done);
}
void Assembler::StoreIntoObjectNoBarrier(Register object,
const Address& dest,
Register value) {
str(value, dest);
#if defined(DEBUG)
Label done;
StoreIntoObjectFilter(object, value, &done, kValueCanBeSmi, kJumpToNoUpdate);
Stop("Store buffer update is required");
Bind(&done);
#endif // defined(DEBUG)
// No store buffer update.
}
void Assembler::StoreIntoObjectOffsetNoBarrier(Register object,
int32_t offset,
Register value) {
if (Address::CanHoldOffset(offset - kHeapObjectTag)) {
StoreIntoObjectNoBarrier(object, FieldAddress(object, offset), value);
} else {
AddImmediate(TMP, object, offset - kHeapObjectTag);
StoreIntoObjectNoBarrier(object, Address(TMP), value);
}
}
void Assembler::StoreIntoObjectNoBarrier(Register object,
const Address& dest,
const Object& value) {
ASSERT(!value.IsICData() || ICData::Cast(value).IsOriginal());
ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
ASSERT(value.IsSmi() || value.InVMHeap() ||
(value.IsOld() && value.IsNotTemporaryScopedHandle()));
// No store buffer update.
LoadObject(TMP2, value);
str(TMP2, dest);
}
void Assembler::StoreIntoObjectOffsetNoBarrier(Register object,
int32_t offset,
const Object& value) {
if (Address::CanHoldOffset(offset - kHeapObjectTag)) {
StoreIntoObjectNoBarrier(object, FieldAddress(object, offset), value);
} else {
AddImmediate(TMP, object, offset - kHeapObjectTag);
StoreIntoObjectNoBarrier(object, Address(TMP), value);
}
}
void Assembler::LoadClassId(Register result, Register object) {
ASSERT(RawObject::kClassIdTagPos == 16);
ASSERT(RawObject::kClassIdTagSize == 16);
const intptr_t class_id_offset =
Object::tags_offset() + RawObject::kClassIdTagPos / kBitsPerByte;
LoadFromOffset(result, object, class_id_offset - kHeapObjectTag,
kUnsignedHalfword);
}
void Assembler::LoadClassById(Register result, Register class_id) {
ASSERT(result != class_id);
LoadIsolate(result);
const intptr_t offset =
Isolate::class_table_offset() + ClassTable::table_offset();
LoadFromOffset(result, result, offset);
ASSERT(kSizeOfClassPairLog2 == 4);
add(class_id, class_id, Operand(class_id));
ldr(result, Address(result, class_id, UXTX, Address::Scaled));
}
void Assembler::LoadClass(Register result, Register object) {
ASSERT(object != TMP);
LoadClassId(TMP, object);
LoadClassById(result, TMP);
}
void Assembler::CompareClassId(Register object,
intptr_t class_id,
Register scratch) {
ASSERT(scratch == kNoRegister);
LoadClassId(TMP, object);
CompareImmediate(TMP, class_id);
}
void Assembler::LoadClassIdMayBeSmi(Register result, Register object) {
ASSERT(result != object);
Label done;
LoadImmediate(result, kSmiCid);
BranchIfSmi(object, &done);
LoadClassId(result, object);
Bind(&done);
}
void Assembler::LoadTaggedClassIdMayBeSmi(Register result, Register object) {
LoadClassIdMayBeSmi(TMP, object);
// Finally, tag the result.
SmiTag(result, TMP);
}
// Frame entry and exit.
void Assembler::ReserveAlignedFrameSpace(intptr_t frame_space) {
// Reserve space for arguments and align frame before entering
// the C++ world.
if (frame_space != 0) {
AddImmediate(SP, -frame_space);
}
if (OS::ActivationFrameAlignment() > 1) {
andi(SP, SP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
}
}
void Assembler::RestoreCodePointer() {
ldr(CODE_REG, Address(FP, kPcMarkerSlotFromFp * kWordSize));
CheckCodePointer();
}
void Assembler::CheckCodePointer() {
#ifdef DEBUG
if (!FLAG_check_code_pointer) {
return;
}
Comment("CheckCodePointer");
Label cid_ok, instructions_ok;
Push(R0);
CompareClassId(CODE_REG, kCodeCid);
b(&cid_ok, EQ);
brk(0);
Bind(&cid_ok);
const intptr_t entry_offset =
CodeSize() + Instructions::HeaderSize() - kHeapObjectTag;
adr(R0, Immediate(-entry_offset));
ldr(TMP, FieldAddress(CODE_REG, Code::saved_instructions_offset()));
cmp(R0, Operand(TMP));
b(&instructions_ok, EQ);
brk(1);
Bind(&instructions_ok);
Pop(R0);
#endif
}
void Assembler::SetupDartSP() {
mov(SP, CSP);
}
void Assembler::RestoreCSP() {
mov(CSP, SP);
}
void Assembler::EnterFrame(intptr_t frame_size) {
// The ARM64 ABI requires at all times
// - stack limit < CSP <= stack base
// - CSP mod 16 = 0
// - we do not access stack memory below CSP
// Pratically, this means we need to keep the C stack pointer ahead of the
// Dart stack pointer and 16-byte aligned for signal handlers. If we knew the
// real stack limit, we could just set CSP to a value near it during
// SetupDartSP, but we do not know the real stack limit for the initial
// thread or threads created by the embedder.
// TODO(26472): It would be safer to use CSP as the Dart stack pointer, but
// this requires adjustments to stack handling to maintain the 16-byte
// alignment.
const intptr_t kMaxDartFrameSize = 4096;
sub(TMP, SP, Operand(kMaxDartFrameSize));
andi(CSP, TMP, Immediate(~15));
PushPair(FP, LR); // low: FP, high: LR.
mov(FP, SP);
if (frame_size > 0) {
sub(SP, SP, Operand(frame_size));
}
}
void Assembler::LeaveFrame() {
mov(SP, FP);
PopPair(FP, LR); // low: FP, high: LR.
}
void Assembler::EnterDartFrame(intptr_t frame_size, Register new_pp) {
ASSERT(!constant_pool_allowed());
// Setup the frame.
EnterFrame(0);
TagAndPushPPAndPcMarker(); // Save PP and PC marker.
// Load the pool pointer.
if (new_pp == kNoRegister) {
LoadPoolPointer();
} else {
mov(PP, new_pp);
set_constant_pool_allowed(true);
}
// Reserve space.
if (frame_size > 0) {
AddImmediate(SP, -frame_size);
}
}
// On entry to a function compiled for OSR, the caller's frame pointer, the
// stack locals, and any copied parameters are already in place. The frame
// pointer is already set up. The PC marker is not correct for the
// optimized function and there may be extra space for spill slots to
// allocate. We must also set up the pool pointer for the function.
void Assembler::EnterOsrFrame(intptr_t extra_size, Register new_pp) {
ASSERT(!constant_pool_allowed());
Comment("EnterOsrFrame");
RestoreCodePointer();
LoadPoolPointer();
if (extra_size > 0) {
AddImmediate(SP, -extra_size);
}
}
void Assembler::LeaveDartFrame(RestorePP restore_pp) {
if (restore_pp == kRestoreCallerPP) {
set_constant_pool_allowed(false);
// Restore and untag PP.
LoadFromOffset(PP, FP, kSavedCallerPpSlotFromFp * kWordSize);
sub(PP, PP, Operand(kHeapObjectTag));
}
LeaveFrame();
}
void Assembler::EnterCallRuntimeFrame(intptr_t frame_size) {
Comment("EnterCallRuntimeFrame");
EnterStubFrame();
// Store fpu registers with the lowest register number at the lowest
// address.
for (int i = kNumberOfVRegisters - 1; i >= 0; i--) {
if ((i >= kAbiFirstPreservedFpuReg) && (i <= kAbiLastPreservedFpuReg)) {
// TODO(zra): When SIMD is added, we must also preserve the top
// 64-bits of the callee-saved registers.
continue;
}
// TODO(zra): Save the whole V register.
VRegister reg = static_cast<VRegister>(i);
PushDouble(reg);
}
for (int i = kDartFirstVolatileCpuReg; i <= kDartLastVolatileCpuReg; i++) {
const Register reg = static_cast<Register>(i);
Push(reg);
}
ReserveAlignedFrameSpace(frame_size);
}
void Assembler::LeaveCallRuntimeFrame() {
// SP might have been modified to reserve space for arguments
// and ensure proper alignment of the stack frame.
// We need to restore it before restoring registers.
const intptr_t kPushedRegistersSize =
kDartVolatileCpuRegCount * kWordSize +
kDartVolatileFpuRegCount * kWordSize +
2 * kWordSize; // PP and pc marker from EnterStubFrame.
AddImmediate(SP, FP, -kPushedRegistersSize);
for (int i = kDartLastVolatileCpuReg; i >= kDartFirstVolatileCpuReg; i--) {
const Register reg = static_cast<Register>(i);
Pop(reg);
}
for (int i = 0; i < kNumberOfVRegisters; i++) {
if ((i >= kAbiFirstPreservedFpuReg) && (i <= kAbiLastPreservedFpuReg)) {
// TODO(zra): When SIMD is added, we must also restore the top
// 64-bits of the callee-saved registers.
continue;
}
// TODO(zra): Restore the whole V register.
VRegister reg = static_cast<VRegister>(i);
PopDouble(reg);
}
LeaveStubFrame();
}
void Assembler::CallRuntime(const RuntimeEntry& entry,
intptr_t argument_count) {
entry.Call(this, argument_count);
}
void Assembler::EnterStubFrame() {
EnterDartFrame(0);
}
void Assembler::LeaveStubFrame() {
LeaveDartFrame();
}
// R0 receiver, R5 guarded cid as Smi.
// Preserve R4 (ARGS_DESC_REG), not required today, but maybe later.
void Assembler::MonomorphicCheckedEntry() {
ASSERT(has_single_entry_point_);
has_single_entry_point_ = false;
bool saved_use_far_branches = use_far_branches();
set_use_far_branches(false);
Label immediate, have_cid, miss;
Bind(&miss);
ldr(IP0, Address(THR, Thread::monomorphic_miss_entry_offset()));
br(IP0);
Bind(&immediate);
movz(IP0, Immediate(kSmiCid), 0);
b(&have_cid);
Comment("MonomorphicCheckedEntry");
ASSERT(CodeSize() == Instructions::kCheckedEntryOffset);
tsti(R0, Immediate(kSmiTagMask));
SmiUntag(R5);
b(&immediate, EQ);
LoadClassId(IP0, R0);
Bind(&have_cid);
cmp(IP0, Operand(R5));
b(&miss, NE);
// Fall through to unchecked entry.
ASSERT(CodeSize() == Instructions::kUncheckedEntryOffset);
set_use_far_branches(saved_use_far_branches);
}
#ifndef PRODUCT
void Assembler::MaybeTraceAllocation(intptr_t cid,
Register temp_reg,
Label* trace) {
ASSERT(cid > 0);
intptr_t state_offset = ClassTable::StateOffsetFor(cid);
LoadIsolate(temp_reg);
intptr_t table_offset =
Isolate::class_table_offset() + ClassTable::TableOffsetFor(cid);
ldr(temp_reg, Address(temp_reg, table_offset));
AddImmediate(temp_reg, state_offset);
ldr(temp_reg, Address(temp_reg, 0));
tsti(temp_reg, Immediate(ClassHeapStats::TraceAllocationMask()));
b(trace, NE);
}
void Assembler::UpdateAllocationStats(intptr_t cid, Heap::Space space) {
ASSERT(cid > 0);
intptr_t counter_offset =
ClassTable::CounterOffsetFor(cid, space == Heap::kNew);
LoadIsolate(TMP2);
intptr_t table_offset =
Isolate::class_table_offset() + ClassTable::TableOffsetFor(cid);
ldr(TMP, Address(TMP2, table_offset));
AddImmediate(TMP2, TMP, counter_offset);
ldr(TMP, Address(TMP2, 0));
AddImmediate(TMP, 1);
str(TMP, Address(TMP2, 0));
}
void Assembler::UpdateAllocationStatsWithSize(intptr_t cid,
Register size_reg,
Heap::Space space) {
ASSERT(cid > 0);
const uword class_offset = ClassTable::ClassOffsetFor(cid);
const uword count_field_offset =
(space == Heap::kNew)
? ClassHeapStats::allocated_since_gc_new_space_offset()
: ClassHeapStats::allocated_since_gc_old_space_offset();
const uword size_field_offset =
(space == Heap::kNew)
? ClassHeapStats::allocated_size_since_gc_new_space_offset()
: ClassHeapStats::allocated_size_since_gc_old_space_offset();
LoadIsolate(TMP2);
intptr_t table_offset =
Isolate::class_table_offset() + ClassTable::TableOffsetFor(cid);
ldr(TMP, Address(TMP2, table_offset));
AddImmediate(TMP2, TMP, class_offset);
ldr(TMP, Address(TMP2, count_field_offset));
AddImmediate(TMP, 1);
str(TMP, Address(TMP2, count_field_offset));
ldr(TMP, Address(TMP2, size_field_offset));
add(TMP, TMP, Operand(size_reg));
str(TMP, Address(TMP2, size_field_offset));
}
#endif // !PRODUCT
void Assembler::TryAllocate(const Class& cls,
Label* failure,
Register instance_reg,
Register temp_reg) {
ASSERT(failure != NULL);
const intptr_t instance_size = cls.instance_size();
if (FLAG_inline_alloc && Heap::IsAllocatableInNewSpace(instance_size)) {
// If this allocation is traced, program will jump to failure path
// (i.e. the allocation stub) which will allocate the object and trace the
// allocation call site.
NOT_IN_PRODUCT(MaybeTraceAllocation(cls.id(), temp_reg, failure));
NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
ldr(instance_reg, Address(THR, Thread::top_offset()));
// TODO(koda): Protect against unsigned overflow here.
AddImmediateSetFlags(instance_reg, instance_reg, instance_size);
// instance_reg: potential next object start.
ldr(TMP, Address(THR, Thread::end_offset()));
CompareRegisters(TMP, instance_reg);
// fail if heap end unsigned less than or equal to instance_reg.
b(failure, LS);
// Successfully allocated the object, now update top to point to
// next object start and store the class in the class field of object.
str(instance_reg, Address(THR, Thread::top_offset()));
ASSERT(instance_size >= kHeapObjectTag);
AddImmediate(instance_reg, -instance_size + kHeapObjectTag);
NOT_IN_PRODUCT(UpdateAllocationStats(cls.id(), space));
uint32_t tags = 0;
tags = RawObject::SizeTag::update(instance_size, tags);
ASSERT(cls.id() != kIllegalCid);
tags = RawObject::ClassIdTag::update(cls.id(), tags);
// Extends the 32 bit tags with zeros, which is the uninitialized
// hash code.
LoadImmediate(TMP, tags);
StoreFieldToOffset(TMP, instance_reg, Object::tags_offset());
} else {
b(failure);
}
}
void Assembler::TryAllocateArray(intptr_t cid,
intptr_t instance_size,
Label* failure,
Register instance,
Register end_address,
Register temp1,
Register temp2) {
if (FLAG_inline_alloc && Heap::IsAllocatableInNewSpace(instance_size)) {
// If this allocation is traced, program will jump to failure path
// (i.e. the allocation stub) which will allocate the object and trace the
// allocation call site.
NOT_IN_PRODUCT(MaybeTraceAllocation(cid, temp1, failure));
NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
// Potential new object start.
ldr(instance, Address(THR, Thread::top_offset()));
AddImmediateSetFlags(end_address, instance, instance_size);
b(failure, CS); // Fail on unsigned overflow.
// Check if the allocation fits into the remaining space.
// instance: potential new object start.
// end_address: potential next object start.
ldr(temp2, Address(THR, Thread::end_offset()));
cmp(end_address, Operand(temp2));
b(failure, CS);
// Successfully allocated the object(s), now update top to point to
// next object start and initialize the object.
str(end_address, Address(THR, Thread::top_offset()));
add(instance, instance, Operand(kHeapObjectTag));
LoadImmediate(temp2, instance_size);
NOT_IN_PRODUCT(UpdateAllocationStatsWithSize(cid, temp2, space));
// Initialize the tags.
// instance: new object start as a tagged pointer.
uint32_t tags = 0;
tags = RawObject::ClassIdTag::update(cid, tags);
tags = RawObject::SizeTag::update(instance_size, tags);
// Extends the 32 bit tags with zeros, which is the uninitialized
// hash code.
LoadImmediate(temp2, tags);
str(temp2, FieldAddress(instance, Array::tags_offset())); // Store tags.
} else {
b(failure);
}
}
Address Assembler::ElementAddressForIntIndex(bool is_external,
intptr_t cid,
intptr_t index_scale,
Register array,
intptr_t index) const {
const int64_t offset =
index * index_scale +
(is_external ? 0 : (Instance::DataOffsetFor(cid) - kHeapObjectTag));
ASSERT(Utils::IsInt(32, offset));
const OperandSize size = Address::OperandSizeFor(cid);
ASSERT(Address::CanHoldOffset(offset, Address::Offset, size));
return Address(array, static_cast<int32_t>(offset), Address::Offset, size);
}
void Assembler::LoadElementAddressForIntIndex(Register address,
bool is_external,
intptr_t cid,
intptr_t index_scale,
Register array,
intptr_t index) {
const int64_t offset =
index * index_scale +
(is_external ? 0 : (Instance::DataOffsetFor(cid) - kHeapObjectTag));
AddImmediate(address, array, offset);
}
Address Assembler::ElementAddressForRegIndex(bool is_load,
bool is_external,
intptr_t cid,
intptr_t index_scale,
Register array,
Register index) {
// Note that index is expected smi-tagged, (i.e, LSL 1) for all arrays.
const intptr_t shift = Utils::ShiftForPowerOfTwo(index_scale) - kSmiTagShift;
const int32_t offset =
is_external ? 0 : (Instance::DataOffsetFor(cid) - kHeapObjectTag);
ASSERT(array != TMP);
ASSERT(index != TMP);
const Register base = is_load ? TMP : index;
if ((offset == 0) && (shift == 0)) {
return Address(array, index, UXTX, Address::Unscaled);
} else if (shift < 0) {
ASSERT(shift == -1);
add(base, array, Operand(index, ASR, 1));
} else {
add(base, array, Operand(index, LSL, shift));
}
const OperandSize size = Address::OperandSizeFor(cid);
ASSERT(Address::CanHoldOffset(offset, Address::Offset, size));
return Address(base, offset, Address::Offset, size);
}
void Assembler::LoadElementAddressForRegIndex(Register address,
bool is_load,
bool is_external,
intptr_t cid,
intptr_t index_scale,
Register array,
Register index) {
// Note that index is expected smi-tagged, (i.e, LSL 1) for all arrays.
const intptr_t shift = Utils::ShiftForPowerOfTwo(index_scale) - kSmiTagShift;
const int32_t offset =
is_external ? 0 : (Instance::DataOffsetFor(cid) - kHeapObjectTag);
if (shift == 0) {
add(address, array, Operand(index));
} else if (shift < 0) {
ASSERT(shift == -1);
add(address, array, Operand(index, ASR, 1));
} else {
add(address, array, Operand(index, LSL, shift));
}
if (offset != 0) {
AddImmediate(address, offset);
}
}
void Assembler::LoadUnaligned(Register dst,
Register addr,
Register tmp,
OperandSize sz) {
ASSERT(dst != addr);
ldr(dst, Address(addr, 0), kUnsignedByte);
if (sz == kHalfword) {
ldr(tmp, Address(addr, 1), kByte);
orr(dst, dst, Operand(tmp, LSL, 8));
return;
}
ldr(tmp, Address(addr, 1), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 8));
if (sz == kUnsignedHalfword) {
return;
}
ldr(tmp, Address(addr, 2), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 16));
if (sz == kWord) {
ldr(tmp, Address(addr, 3), kByte);
orr(dst, dst, Operand(tmp, LSL, 24));
return;
}
ldr(tmp, Address(addr, 3), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 24));
if (sz == kUnsignedWord) {
return;
}
ldr(tmp, Address(addr, 4), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 32));
ldr(tmp, Address(addr, 5), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 40));
ldr(tmp, Address(addr, 6), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 48));
ldr(tmp, Address(addr, 7), kUnsignedByte);
orr(dst, dst, Operand(tmp, LSL, 56));
if (sz == kDoubleWord) {
return;
}
UNIMPLEMENTED();
}
void Assembler::StoreUnaligned(Register src,
Register addr,
Register tmp,
OperandSize sz) {
str(src, Address(addr, 0), kUnsignedByte);
LsrImmediate(tmp, src, 8);
str(tmp, Address(addr, 1), kUnsignedByte);
if ((sz == kHalfword) || (sz == kUnsignedHalfword)) {
return;
}
LsrImmediate(tmp, src, 16);
str(tmp, Address(addr, 2), kUnsignedByte);
LsrImmediate(tmp, src, 24);
str(tmp, Address(addr, 3), kUnsignedByte);
if ((sz == kWord) || (sz == kUnsignedWord)) {
return;
}
LsrImmediate(tmp, src, 32);
str(tmp, Address(addr, 4), kUnsignedByte);
LsrImmediate(tmp, src, 40);
str(tmp, Address(addr, 5), kUnsignedByte);
LsrImmediate(tmp, src, 48);
str(tmp, Address(addr, 6), kUnsignedByte);
LsrImmediate(tmp, src, 56);
str(tmp, Address(addr, 7), kUnsignedByte);
if (sz == kDoubleWord) {
return;
}
UNIMPLEMENTED();
}
} // namespace dart
#endif // defined(TARGET_ARCH_ARM64) && !defined(DART_PRECOMPILED_RUNTIME)