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android / platform / external / v8 / e537f38c36600fd0f3026adba6b3f4cbcee1fb29 / . / src / arm64 / macro-assembler-arm64.cc
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// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/v8.h"
#if V8_TARGET_ARCH_ARM64
#include "src/base/bits.h"
#include "src/base/division-by-constant.h"
#include "src/bootstrapper.h"
#include "src/codegen.h"
#include "src/cpu-profiler.h"
#include "src/debug.h"
#include "src/isolate-inl.h"
#include "src/runtime/runtime.h"
namespace v8 {
namespace internal {
// Define a fake double underscore to use with the ASM_UNIMPLEMENTED macros.
#define __
MacroAssembler::MacroAssembler(Isolate* arg_isolate,
byte * buffer,
unsigned buffer_size)
: Assembler(arg_isolate, buffer, buffer_size),
generating_stub_(false),
#if DEBUG
allow_macro_instructions_(true),
#endif
has_frame_(false),
use_real_aborts_(true),
sp_(jssp),
tmp_list_(DefaultTmpList()),
fptmp_list_(DefaultFPTmpList()) {
if (isolate() != NULL) {
code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
isolate());
}
}
CPURegList MacroAssembler::DefaultTmpList() {
return CPURegList(ip0, ip1);
}
CPURegList MacroAssembler::DefaultFPTmpList() {
return CPURegList(fp_scratch1, fp_scratch2);
}
void MacroAssembler::LogicalMacro(const Register& rd,
const Register& rn,
const Operand& operand,
LogicalOp op) {
UseScratchRegisterScope temps(this);
if (operand.NeedsRelocation(this)) {
Register temp = temps.AcquireX();
Ldr(temp, operand.immediate());
Logical(rd, rn, temp, op);
} else if (operand.IsImmediate()) {
int64_t immediate = operand.ImmediateValue();
unsigned reg_size = rd.SizeInBits();
// If the operation is NOT, invert the operation and immediate.
if ((op & NOT) == NOT) {
op = static_cast<LogicalOp>(op & ~NOT);
immediate = ~immediate;
}
// Ignore the top 32 bits of an immediate if we're moving to a W register.
if (rd.Is32Bits()) {
// Check that the top 32 bits are consistent.
DCHECK(((immediate >> kWRegSizeInBits) == 0) ||
((immediate >> kWRegSizeInBits) == -1));
immediate &= kWRegMask;
}
DCHECK(rd.Is64Bits() || is_uint32(immediate));
// Special cases for all set or all clear immediates.
if (immediate == 0) {
switch (op) {
case AND:
Mov(rd, 0);
return;
case ORR: // Fall through.
case EOR:
Mov(rd, rn);
return;
case ANDS: // Fall through.
case BICS:
break;
default:
UNREACHABLE();
}
} else if ((rd.Is64Bits() && (immediate == -1L)) ||
(rd.Is32Bits() && (immediate == 0xffffffffL))) {
switch (op) {
case AND:
Mov(rd, rn);
return;
case ORR:
Mov(rd, immediate);
return;
case EOR:
Mvn(rd, rn);
return;
case ANDS: // Fall through.
case BICS:
break;
default:
UNREACHABLE();
}
}
unsigned n, imm_s, imm_r;
if (IsImmLogical(immediate, reg_size, &n, &imm_s, &imm_r)) {
// Immediate can be encoded in the instruction.
LogicalImmediate(rd, rn, n, imm_s, imm_r, op);
} else {
// Immediate can't be encoded: synthesize using move immediate.
Register temp = temps.AcquireSameSizeAs(rn);
Operand imm_operand = MoveImmediateForShiftedOp(temp, immediate);
if (rd.Is(csp)) {
// If rd is the stack pointer we cannot use it as the destination
// register so we use the temp register as an intermediate again.
Logical(temp, rn, imm_operand, op);
Mov(csp, temp);
AssertStackConsistency();
} else {
Logical(rd, rn, imm_operand, op);
}
}
} else if (operand.IsExtendedRegister()) {
DCHECK(operand.reg().SizeInBits() <= rd.SizeInBits());
// Add/sub extended supports shift <= 4. We want to support exactly the
// same modes here.
DCHECK(operand.shift_amount() <= 4);
DCHECK(operand.reg().Is64Bits() ||
((operand.extend() != UXTX) && (operand.extend() != SXTX)));
Register temp = temps.AcquireSameSizeAs(rn);
EmitExtendShift(temp, operand.reg(), operand.extend(),
operand.shift_amount());
Logical(rd, rn, temp, op);
} else {
// The operand can be encoded in the instruction.
DCHECK(operand.IsShiftedRegister());
Logical(rd, rn, operand, op);
}
}
void MacroAssembler::Mov(const Register& rd, uint64_t imm) {
DCHECK(allow_macro_instructions_);
DCHECK(is_uint32(imm) || is_int32(imm) || rd.Is64Bits());
DCHECK(!rd.IsZero());
// TODO(all) extend to support more immediates.
//
// Immediates on Aarch64 can be produced using an initial value, and zero to
// three move keep operations.
//
// Initial values can be generated with:
// 1. 64-bit move zero (movz).
// 2. 32-bit move inverted (movn).
// 3. 64-bit move inverted.
// 4. 32-bit orr immediate.
// 5. 64-bit orr immediate.
// Move-keep may then be used to modify each of the 16-bit half-words.
//
// The code below supports all five initial value generators, and
// applying move-keep operations to move-zero and move-inverted initial
// values.
// Try to move the immediate in one instruction, and if that fails, switch to
// using multiple instructions.
if (!TryOneInstrMoveImmediate(rd, imm)) {
unsigned reg_size = rd.SizeInBits();
// Generic immediate case. Imm will be represented by
// [imm3, imm2, imm1, imm0], where each imm is 16 bits.
// A move-zero or move-inverted is generated for the first non-zero or
// non-0xffff immX, and a move-keep for subsequent non-zero immX.
uint64_t ignored_halfword = 0;
bool invert_move = false;
// If the number of 0xffff halfwords is greater than the number of 0x0000
// halfwords, it's more efficient to use move-inverted.
if (CountClearHalfWords(~imm, reg_size) >
CountClearHalfWords(imm, reg_size)) {
ignored_halfword = 0xffffL;
invert_move = true;
}
// Mov instructions can't move immediate values into the stack pointer, so
// set up a temporary register, if needed.
UseScratchRegisterScope temps(this);
Register temp = rd.IsSP() ? temps.AcquireSameSizeAs(rd) : rd;
// Iterate through the halfwords. Use movn/movz for the first non-ignored
// halfword, and movk for subsequent halfwords.
DCHECK((reg_size % 16) == 0);
bool first_mov_done = false;
for (unsigned i = 0; i < (rd.SizeInBits() / 16); i++) {
uint64_t imm16 = (imm >> (16 * i)) & 0xffffL;
if (imm16 != ignored_halfword) {
if (!first_mov_done) {
if (invert_move) {
movn(temp, (~imm16) & 0xffffL, 16 * i);
} else {
movz(temp, imm16, 16 * i);
}
first_mov_done = true;
} else {
// Construct a wider constant.
movk(temp, imm16, 16 * i);
}
}
}
DCHECK(first_mov_done);
// Move the temporary if the original destination register was the stack
// pointer.
if (rd.IsSP()) {
mov(rd, temp);
AssertStackConsistency();
}
}
}
void MacroAssembler::Mov(const Register& rd,
const Operand& operand,
DiscardMoveMode discard_mode) {
DCHECK(allow_macro_instructions_);
DCHECK(!rd.IsZero());
// Provide a swap register for instructions that need to write into the
// system stack pointer (and can't do this inherently).
UseScratchRegisterScope temps(this);
Register dst = (rd.IsSP()) ? temps.AcquireSameSizeAs(rd) : rd;
if (operand.NeedsRelocation(this)) {
Ldr(dst, operand.immediate());
} else if (operand.IsImmediate()) {
// Call the macro assembler for generic immediates.
Mov(dst, operand.ImmediateValue());
} else if (operand.IsShiftedRegister() && (operand.shift_amount() != 0)) {
// Emit a shift instruction if moving a shifted register. This operation
// could also be achieved using an orr instruction (like orn used by Mvn),
// but using a shift instruction makes the disassembly clearer.
EmitShift(dst, operand.reg(), operand.shift(), operand.shift_amount());
} else if (operand.IsExtendedRegister()) {
// Emit an extend instruction if moving an extended register. This handles
// extend with post-shift operations, too.
EmitExtendShift(dst, operand.reg(), operand.extend(),
operand.shift_amount());
} else {
// Otherwise, emit a register move only if the registers are distinct, or
// if they are not X registers.
//
// Note that mov(w0, w0) is not a no-op because it clears the top word of
// x0. A flag is provided (kDiscardForSameWReg) if a move between the same W
// registers is not required to clear the top word of the X register. In
// this case, the instruction is discarded.
//
// If csp is an operand, add #0 is emitted, otherwise, orr #0.
if (!rd.Is(operand.reg()) || (rd.Is32Bits() &&
(discard_mode == kDontDiscardForSameWReg))) {
Assembler::mov(rd, operand.reg());
}
// This case can handle writes into the system stack pointer directly.
dst = rd;
}
// Copy the result to the system stack pointer.
if (!dst.Is(rd)) {
DCHECK(rd.IsSP());
Assembler::mov(rd, dst);
}
}
void MacroAssembler::Mvn(const Register& rd, const Operand& operand) {
DCHECK(allow_macro_instructions_);
if (operand.NeedsRelocation(this)) {
Ldr(rd, operand.immediate());
mvn(rd, rd);
} else if (operand.IsImmediate()) {
// Call the macro assembler for generic immediates.
Mov(rd, ~operand.ImmediateValue());
} else if (operand.IsExtendedRegister()) {
// Emit two instructions for the extend case. This differs from Mov, as
// the extend and invert can't be achieved in one instruction.
EmitExtendShift(rd, operand.reg(), operand.extend(),
operand.shift_amount());
mvn(rd, rd);
} else {
mvn(rd, operand);
}
}
unsigned MacroAssembler::CountClearHalfWords(uint64_t imm, unsigned reg_size) {
DCHECK((reg_size % 8) == 0);
int count = 0;
for (unsigned i = 0; i < (reg_size / 16); i++) {
if ((imm & 0xffff) == 0) {
count++;
}
imm >>= 16;
}
return count;
}
// The movz instruction can generate immediates containing an arbitrary 16-bit
// half-word, with remaining bits clear, eg. 0x00001234, 0x0000123400000000.
bool MacroAssembler::IsImmMovz(uint64_t imm, unsigned reg_size) {
DCHECK((reg_size == kXRegSizeInBits) || (reg_size == kWRegSizeInBits));
return CountClearHalfWords(imm, reg_size) >= ((reg_size / 16) - 1);
}
// The movn instruction can generate immediates containing an arbitrary 16-bit
// half-word, with remaining bits set, eg. 0xffff1234, 0xffff1234ffffffff.
bool MacroAssembler::IsImmMovn(uint64_t imm, unsigned reg_size) {
return IsImmMovz(~imm, reg_size);
}
void MacroAssembler::ConditionalCompareMacro(const Register& rn,
const Operand& operand,
StatusFlags nzcv,
Condition cond,
ConditionalCompareOp op) {
DCHECK((cond != al) && (cond != nv));
if (operand.NeedsRelocation(this)) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, operand.immediate());
ConditionalCompareMacro(rn, temp, nzcv, cond, op);
} else if ((operand.IsShiftedRegister() && (operand.shift_amount() == 0)) ||
(operand.IsImmediate() &&
IsImmConditionalCompare(operand.ImmediateValue()))) {
// The immediate can be encoded in the instruction, or the operand is an
// unshifted register: call the assembler.
ConditionalCompare(rn, operand, nzcv, cond, op);
} else {
// The operand isn't directly supported by the instruction: perform the
// operation on a temporary register.
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(rn);
Mov(temp, operand);
ConditionalCompare(rn, temp, nzcv, cond, op);
}
}
void MacroAssembler::Csel(const Register& rd,
const Register& rn,
const Operand& operand,
Condition cond) {
DCHECK(allow_macro_instructions_);
DCHECK(!rd.IsZero());
DCHECK((cond != al) && (cond != nv));
if (operand.IsImmediate()) {
// Immediate argument. Handle special cases of 0, 1 and -1 using zero
// register.
int64_t imm = operand.ImmediateValue();
Register zr = AppropriateZeroRegFor(rn);
if (imm == 0) {
csel(rd, rn, zr, cond);
} else if (imm == 1) {
csinc(rd, rn, zr, cond);
} else if (imm == -1) {
csinv(rd, rn, zr, cond);
} else {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(rn);
Mov(temp, imm);
csel(rd, rn, temp, cond);
}
} else if (operand.IsShiftedRegister() && (operand.shift_amount() == 0)) {
// Unshifted register argument.
csel(rd, rn, operand.reg(), cond);
} else {
// All other arguments.
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(rn);
Mov(temp, operand);
csel(rd, rn, temp, cond);
}
}
bool MacroAssembler::TryOneInstrMoveImmediate(const Register& dst,
int64_t imm) {
unsigned n, imm_s, imm_r;
int reg_size = dst.SizeInBits();
if (IsImmMovz(imm, reg_size) && !dst.IsSP()) {
// Immediate can be represented in a move zero instruction. Movz can't write
// to the stack pointer.
movz(dst, imm);
return true;
} else if (IsImmMovn(imm, reg_size) && !dst.IsSP()) {
// Immediate can be represented in a move not instruction. Movn can't write
// to the stack pointer.
movn(dst, dst.Is64Bits() ? ~imm : (~imm & kWRegMask));
return true;
} else if (IsImmLogical(imm, reg_size, &n, &imm_s, &imm_r)) {
// Immediate can be represented in a logical orr instruction.
LogicalImmediate(dst, AppropriateZeroRegFor(dst), n, imm_s, imm_r, ORR);
return true;
}
return false;
}
Operand MacroAssembler::MoveImmediateForShiftedOp(const Register& dst,
int64_t imm) {
int reg_size = dst.SizeInBits();
// Encode the immediate in a single move instruction, if possible.
if (TryOneInstrMoveImmediate(dst, imm)) {
// The move was successful; nothing to do here.
} else {
// Pre-shift the immediate to the least-significant bits of the register.
int shift_low = CountTrailingZeros(imm, reg_size);
int64_t imm_low = imm >> shift_low;
// Pre-shift the immediate to the most-significant bits of the register. We
// insert set bits in the least-significant bits, as this creates a
// different immediate that may be encodable using movn or orr-immediate.
// If this new immediate is encodable, the set bits will be eliminated by
// the post shift on the following instruction.
int shift_high = CountLeadingZeros(imm, reg_size);
int64_t imm_high = (imm << shift_high) | ((1 << shift_high) - 1);
if (TryOneInstrMoveImmediate(dst, imm_low)) {
// The new immediate has been moved into the destination's low bits:
// return a new leftward-shifting operand.
return Operand(dst, LSL, shift_low);
} else if (TryOneInstrMoveImmediate(dst, imm_high)) {
// The new immediate has been moved into the destination's high bits:
// return a new rightward-shifting operand.
return Operand(dst, LSR, shift_high);
} else {
// Use the generic move operation to set up the immediate.
Mov(dst, imm);
}
}
return Operand(dst);
}
void MacroAssembler::AddSubMacro(const Register& rd,
const Register& rn,
const Operand& operand,
FlagsUpdate S,
AddSubOp op) {
if (operand.IsZero() && rd.Is(rn) && rd.Is64Bits() && rn.Is64Bits() &&
!operand.NeedsRelocation(this) && (S == LeaveFlags)) {
// The instruction would be a nop. Avoid generating useless code.
return;
}
if (operand.NeedsRelocation(this)) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, operand.immediate());
AddSubMacro(rd, rn, temp, S, op);
} else if ((operand.IsImmediate() &&
!IsImmAddSub(operand.ImmediateValue())) ||
(rn.IsZero() && !operand.IsShiftedRegister()) ||
(operand.IsShiftedRegister() && (operand.shift() == ROR))) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(rn);
if (operand.IsImmediate()) {
Operand imm_operand =
MoveImmediateForShiftedOp(temp, operand.ImmediateValue());
AddSub(rd, rn, imm_operand, S, op);
} else {
Mov(temp, operand);
AddSub(rd, rn, temp, S, op);
}
} else {
AddSub(rd, rn, operand, S, op);
}
}
void MacroAssembler::AddSubWithCarryMacro(const Register& rd,
const Register& rn,
const Operand& operand,
FlagsUpdate S,
AddSubWithCarryOp op) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
UseScratchRegisterScope temps(this);
if (operand.NeedsRelocation(this)) {
Register temp = temps.AcquireX();
Ldr(temp, operand.immediate());
AddSubWithCarryMacro(rd, rn, temp, S, op);
} else if (operand.IsImmediate() ||
(operand.IsShiftedRegister() && (operand.shift() == ROR))) {
// Add/sub with carry (immediate or ROR shifted register.)
Register temp = temps.AcquireSameSizeAs(rn);
Mov(temp, operand);
AddSubWithCarry(rd, rn, temp, S, op);
} else if (operand.IsShiftedRegister() && (operand.shift_amount() != 0)) {
// Add/sub with carry (shifted register).
DCHECK(operand.reg().SizeInBits() == rd.SizeInBits());
DCHECK(operand.shift() != ROR);
DCHECK(is_uintn(operand.shift_amount(),
rd.SizeInBits() == kXRegSizeInBits ? kXRegSizeInBitsLog2
: kWRegSizeInBitsLog2));
Register temp = temps.AcquireSameSizeAs(rn);
EmitShift(temp, operand.reg(), operand.shift(), operand.shift_amount());
AddSubWithCarry(rd, rn, temp, S, op);
} else if (operand.IsExtendedRegister()) {
// Add/sub with carry (extended register).
DCHECK(operand.reg().SizeInBits() <= rd.SizeInBits());
// Add/sub extended supports a shift <= 4. We want to support exactly the
// same modes.
DCHECK(operand.shift_amount() <= 4);
DCHECK(operand.reg().Is64Bits() ||
((operand.extend() != UXTX) && (operand.extend() != SXTX)));
Register temp = temps.AcquireSameSizeAs(rn);
EmitExtendShift(temp, operand.reg(), operand.extend(),
operand.shift_amount());
AddSubWithCarry(rd, rn, temp, S, op);
} else {
// The addressing mode is directly supported by the instruction.
AddSubWithCarry(rd, rn, operand, S, op);
}
}
void MacroAssembler::LoadStoreMacro(const CPURegister& rt,
const MemOperand& addr,
LoadStoreOp op) {
int64_t offset = addr.offset();
LSDataSize size = CalcLSDataSize(op);
// Check if an immediate offset fits in the immediate field of the
// appropriate instruction. If not, emit two instructions to perform
// the operation.
if (addr.IsImmediateOffset() && !IsImmLSScaled(offset, size) &&
!IsImmLSUnscaled(offset)) {
// Immediate offset that can't be encoded using unsigned or unscaled
// addressing modes.
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(addr.base());
Mov(temp, addr.offset());
LoadStore(rt, MemOperand(addr.base(), temp), op);
} else if (addr.IsPostIndex() && !IsImmLSUnscaled(offset)) {
// Post-index beyond unscaled addressing range.
LoadStore(rt, MemOperand(addr.base()), op);
add(addr.base(), addr.base(), offset);
} else if (addr.IsPreIndex() && !IsImmLSUnscaled(offset)) {
// Pre-index beyond unscaled addressing range.
add(addr.base(), addr.base(), offset);
LoadStore(rt, MemOperand(addr.base()), op);
} else {
// Encodable in one load/store instruction.
LoadStore(rt, addr, op);
}
}
void MacroAssembler::LoadStorePairMacro(const CPURegister& rt,
const CPURegister& rt2,
const MemOperand& addr,
LoadStorePairOp op) {
// TODO(all): Should we support register offset for load-store-pair?
DCHECK(!addr.IsRegisterOffset());
int64_t offset = addr.offset();
LSDataSize size = CalcLSPairDataSize(op);
// Check if the offset fits in the immediate field of the appropriate
// instruction. If not, emit two instructions to perform the operation.
if (IsImmLSPair(offset, size)) {
// Encodable in one load/store pair instruction.
LoadStorePair(rt, rt2, addr, op);
} else {
Register base = addr.base();
if (addr.IsImmediateOffset()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(base);
Add(temp, base, offset);
LoadStorePair(rt, rt2, MemOperand(temp), op);
} else if (addr.IsPostIndex()) {
LoadStorePair(rt, rt2, MemOperand(base), op);
Add(base, base, offset);
} else {
DCHECK(addr.IsPreIndex());
Add(base, base, offset);
LoadStorePair(rt, rt2, MemOperand(base), op);
}
}
}
void MacroAssembler::Load(const Register& rt,
const MemOperand& addr,
Representation r) {
DCHECK(!r.IsDouble());
if (r.IsInteger8()) {
Ldrsb(rt, addr);
} else if (r.IsUInteger8()) {
Ldrb(rt, addr);
} else if (r.IsInteger16()) {
Ldrsh(rt, addr);
} else if (r.IsUInteger16()) {
Ldrh(rt, addr);
} else if (r.IsInteger32()) {
Ldr(rt.W(), addr);
} else {
DCHECK(rt.Is64Bits());
Ldr(rt, addr);
}
}
void MacroAssembler::Store(const Register& rt,
const MemOperand& addr,
Representation r) {
DCHECK(!r.IsDouble());
if (r.IsInteger8() || r.IsUInteger8()) {
Strb(rt, addr);
} else if (r.IsInteger16() || r.IsUInteger16()) {
Strh(rt, addr);
} else if (r.IsInteger32()) {
Str(rt.W(), addr);
} else {
DCHECK(rt.Is64Bits());
if (r.IsHeapObject()) {
AssertNotSmi(rt);
} else if (r.IsSmi()) {
AssertSmi(rt);
}
Str(rt, addr);
}
}
bool MacroAssembler::NeedExtraInstructionsOrRegisterBranch(
Label *label, ImmBranchType b_type) {
bool need_longer_range = false;
// There are two situations in which we care about the offset being out of
// range:
// - The label is bound but too far away.
// - The label is not bound but linked, and the previous branch
// instruction in the chain is too far away.
if (label->is_bound() || label->is_linked()) {
need_longer_range =
!Instruction::IsValidImmPCOffset(b_type, label->pos() - pc_offset());
}
if (!need_longer_range && !label->is_bound()) {
int max_reachable_pc = pc_offset() + Instruction::ImmBranchRange(b_type);
unresolved_branches_.insert(
std::pair<int, FarBranchInfo>(max_reachable_pc,
FarBranchInfo(pc_offset(), label)));
// Also maintain the next pool check.
next_veneer_pool_check_ =
Min(next_veneer_pool_check_,
max_reachable_pc - kVeneerDistanceCheckMargin);
}
return need_longer_range;
}
void MacroAssembler::Adr(const Register& rd, Label* label, AdrHint hint) {
DCHECK(allow_macro_instructions_);
DCHECK(!rd.IsZero());
if (hint == kAdrNear) {
adr(rd, label);
return;
}
DCHECK(hint == kAdrFar);
if (label->is_bound()) {
int label_offset = label->pos() - pc_offset();
if (Instruction::IsValidPCRelOffset(label_offset)) {
adr(rd, label);
} else {
DCHECK(label_offset <= 0);
int min_adr_offset = -(1 << (Instruction::ImmPCRelRangeBitwidth - 1));
adr(rd, min_adr_offset);
Add(rd, rd, label_offset - min_adr_offset);
}
} else {
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
InstructionAccurateScope scope(
this, PatchingAssembler::kAdrFarPatchableNInstrs);
adr(rd, label);
for (int i = 0; i < PatchingAssembler::kAdrFarPatchableNNops; ++i) {
nop(ADR_FAR_NOP);
}
movz(scratch, 0);
}
}
void MacroAssembler::B(Label* label, BranchType type, Register reg, int bit) {
DCHECK((reg.Is(NoReg) || type >= kBranchTypeFirstUsingReg) &&
(bit == -1 || type >= kBranchTypeFirstUsingBit));
if (kBranchTypeFirstCondition <= type && type <= kBranchTypeLastCondition) {
B(static_cast<Condition>(type), label);
} else {
switch (type) {
case always: B(label); break;
case never: break;
case reg_zero: Cbz(reg, label); break;
case reg_not_zero: Cbnz(reg, label); break;
case reg_bit_clear: Tbz(reg, bit, label); break;
case reg_bit_set: Tbnz(reg, bit, label); break;
default:
UNREACHABLE();
}
}
}
void MacroAssembler::B(Label* label, Condition cond) {
DCHECK(allow_macro_instructions_);
DCHECK((cond != al) && (cond != nv));
Label done;
bool need_extra_instructions =
NeedExtraInstructionsOrRegisterBranch(label, CondBranchType);
if (need_extra_instructions) {
b(&done, NegateCondition(cond));
B(label);
} else {
b(label, cond);
}
bind(&done);
}
void MacroAssembler::Tbnz(const Register& rt, unsigned bit_pos, Label* label) {
DCHECK(allow_macro_instructions_);
Label done;
bool need_extra_instructions =
NeedExtraInstructionsOrRegisterBranch(label, TestBranchType);
if (need_extra_instructions) {
tbz(rt, bit_pos, &done);
B(label);
} else {
tbnz(rt, bit_pos, label);
}
bind(&done);
}
void MacroAssembler::Tbz(const Register& rt, unsigned bit_pos, Label* label) {
DCHECK(allow_macro_instructions_);
Label done;
bool need_extra_instructions =
NeedExtraInstructionsOrRegisterBranch(label, TestBranchType);
if (need_extra_instructions) {
tbnz(rt, bit_pos, &done);
B(label);
} else {
tbz(rt, bit_pos, label);
}
bind(&done);
}
void MacroAssembler::Cbnz(const Register& rt, Label* label) {
DCHECK(allow_macro_instructions_);
Label done;
bool need_extra_instructions =
NeedExtraInstructionsOrRegisterBranch(label, CompareBranchType);
if (need_extra_instructions) {
cbz(rt, &done);
B(label);
} else {
cbnz(rt, label);
}
bind(&done);
}
void MacroAssembler::Cbz(const Register& rt, Label* label) {
DCHECK(allow_macro_instructions_);
Label done;
bool need_extra_instructions =
NeedExtraInstructionsOrRegisterBranch(label, CompareBranchType);
if (need_extra_instructions) {
cbnz(rt, &done);
B(label);
} else {
cbz(rt, label);
}
bind(&done);
}
// Pseudo-instructions.
void MacroAssembler::Abs(const Register& rd, const Register& rm,
Label* is_not_representable,
Label* is_representable) {
DCHECK(allow_macro_instructions_);
DCHECK(AreSameSizeAndType(rd, rm));
Cmp(rm, 1);
Cneg(rd, rm, lt);
// If the comparison sets the v flag, the input was the smallest value
// representable by rm, and the mathematical result of abs(rm) is not
// representable using two's complement.
if ((is_not_representable != NULL) && (is_representable != NULL)) {
B(is_not_representable, vs);
B(is_representable);
} else if (is_not_representable != NULL) {
B(is_not_representable, vs);
} else if (is_representable != NULL) {
B(is_representable, vc);
}
}
// Abstracted stack operations.
void MacroAssembler::Push(const CPURegister& src0, const CPURegister& src1,
const CPURegister& src2, const CPURegister& src3) {
DCHECK(AreSameSizeAndType(src0, src1, src2, src3));
int count = 1 + src1.IsValid() + src2.IsValid() + src3.IsValid();
int size = src0.SizeInBytes();
PushPreamble(count, size);
PushHelper(count, size, src0, src1, src2, src3);
}
void MacroAssembler::Push(const CPURegister& src0, const CPURegister& src1,
const CPURegister& src2, const CPURegister& src3,
const CPURegister& src4, const CPURegister& src5,
const CPURegister& src6, const CPURegister& src7) {
DCHECK(AreSameSizeAndType(src0, src1, src2, src3, src4, src5, src6, src7));
int count = 5 + src5.IsValid() + src6.IsValid() + src6.IsValid();
int size = src0.SizeInBytes();
PushPreamble(count, size);
PushHelper(4, size, src0, src1, src2, src3);
PushHelper(count - 4, size, src4, src5, src6, src7);
}
void MacroAssembler::Pop(const CPURegister& dst0, const CPURegister& dst1,
const CPURegister& dst2, const CPURegister& dst3) {
// It is not valid to pop into the same register more than once in one
// instruction, not even into the zero register.
DCHECK(!AreAliased(dst0, dst1, dst2, dst3));
DCHECK(AreSameSizeAndType(dst0, dst1, dst2, dst3));
DCHECK(dst0.IsValid());
int count = 1 + dst1.IsValid() + dst2.IsValid() + dst3.IsValid();
int size = dst0.SizeInBytes();
PopHelper(count, size, dst0, dst1, dst2, dst3);
PopPostamble(count, size);
}
void MacroAssembler::Push(const Register& src0, const FPRegister& src1) {
int size = src0.SizeInBytes() + src1.SizeInBytes();
PushPreamble(size);
// Reserve room for src0 and push src1.
str(src1, MemOperand(StackPointer(), -size, PreIndex));
// Fill the gap with src0.
str(src0, MemOperand(StackPointer(), src1.SizeInBytes()));
}
void MacroAssembler::PushPopQueue::PushQueued(
PreambleDirective preamble_directive) {
if (queued_.empty()) return;
if (preamble_directive == WITH_PREAMBLE) {
masm_->PushPreamble(size_);
}
int count = queued_.size();
int index = 0;
while (index < count) {
// PushHelper can only handle registers with the same size and type, and it
// can handle only four at a time. Batch them up accordingly.
CPURegister batch[4] = {NoReg, NoReg, NoReg, NoReg};
int batch_index = 0;
do {
batch[batch_index++] = queued_[index++];
} while ((batch_index < 4) && (index < count) &&
batch[0].IsSameSizeAndType(queued_[index]));
masm_->PushHelper(batch_index, batch[0].SizeInBytes(),
batch[0], batch[1], batch[2], batch[3]);
}
queued_.clear();
}
void MacroAssembler::PushPopQueue::PopQueued() {
if (queued_.empty()) return;
int count = queued_.size();
int index = 0;
while (index < count) {
// PopHelper can only handle registers with the same size and type, and it
// can handle only four at a time. Batch them up accordingly.
CPURegister batch[4] = {NoReg, NoReg, NoReg, NoReg};
int batch_index = 0;
do {
batch[batch_index++] = queued_[index++];
} while ((batch_index < 4) && (index < count) &&
batch[0].IsSameSizeAndType(queued_[index]));
masm_->PopHelper(batch_index, batch[0].SizeInBytes(),
batch[0], batch[1], batch[2], batch[3]);
}
masm_->PopPostamble(size_);
queued_.clear();
}
void MacroAssembler::PushCPURegList(CPURegList registers) {
int size = registers.RegisterSizeInBytes();
PushPreamble(registers.Count(), size);
// Push up to four registers at a time because if the current stack pointer is
// csp and reg_size is 32, registers must be pushed in blocks of four in order
// to maintain the 16-byte alignment for csp.
while (!registers.IsEmpty()) {
int count_before = registers.Count();
const CPURegister& src0 = registers.PopHighestIndex();
const CPURegister& src1 = registers.PopHighestIndex();
const CPURegister& src2 = registers.PopHighestIndex();
const CPURegister& src3 = registers.PopHighestIndex();
int count = count_before - registers.Count();
PushHelper(count, size, src0, src1, src2, src3);
}
}
void MacroAssembler::PopCPURegList(CPURegList registers) {
int size = registers.RegisterSizeInBytes();
// Pop up to four registers at a time because if the current stack pointer is
// csp and reg_size is 32, registers must be pushed in blocks of four in
// order to maintain the 16-byte alignment for csp.
while (!registers.IsEmpty()) {
int count_before = registers.Count();
const CPURegister& dst0 = registers.PopLowestIndex();
const CPURegister& dst1 = registers.PopLowestIndex();
const CPURegister& dst2 = registers.PopLowestIndex();
const CPURegister& dst3 = registers.PopLowestIndex();
int count = count_before - registers.Count();
PopHelper(count, size, dst0, dst1, dst2, dst3);
}
PopPostamble(registers.Count(), size);
}
void MacroAssembler::PushMultipleTimes(CPURegister src, int count) {
int size = src.SizeInBytes();
PushPreamble(count, size);
if (FLAG_optimize_for_size && count > 8) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Label loop;
__ Mov(temp, count / 2);
__ Bind(&loop);
PushHelper(2, size, src, src, NoReg, NoReg);
__ Subs(temp, temp, 1);
__ B(ne, &loop);
count %= 2;
}
// Push up to four registers at a time if possible because if the current
// stack pointer is csp and the register size is 32, registers must be pushed
// in blocks of four in order to maintain the 16-byte alignment for csp.
while (count >= 4) {
PushHelper(4, size, src, src, src, src);
count -= 4;
}
if (count >= 2) {
PushHelper(2, size, src, src, NoReg, NoReg);
count -= 2;
}
if (count == 1) {
PushHelper(1, size, src, NoReg, NoReg, NoReg);
count -= 1;
}
DCHECK(count == 0);
}
void MacroAssembler::PushMultipleTimes(CPURegister src, Register count) {
PushPreamble(Operand(count, UXTW, WhichPowerOf2(src.SizeInBytes())));
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireSameSizeAs(count);
if (FLAG_optimize_for_size) {
Label loop, done;
Subs(temp, count, 1);
B(mi, &done);
// Push all registers individually, to save code size.
Bind(&loop);
Subs(temp, temp, 1);
PushHelper(1, src.SizeInBytes(), src, NoReg, NoReg, NoReg);
B(pl, &loop);
Bind(&done);
} else {
Label loop, leftover2, leftover1, done;
Subs(temp, count, 4);
B(mi, &leftover2);
// Push groups of four first.
Bind(&loop);
Subs(temp, temp, 4);
PushHelper(4, src.SizeInBytes(), src, src, src, src);
B(pl, &loop);
// Push groups of two.
Bind(&leftover2);
Tbz(count, 1, &leftover1);
PushHelper(2, src.SizeInBytes(), src, src, NoReg, NoReg);
// Push the last one (if required).
Bind(&leftover1);
Tbz(count, 0, &done);
PushHelper(1, src.SizeInBytes(), src, NoReg, NoReg, NoReg);
Bind(&done);
}
}
void MacroAssembler::PushHelper(int count, int size,
const CPURegister& src0,
const CPURegister& src1,
const CPURegister& src2,
const CPURegister& src3) {
// Ensure that we don't unintentially modify scratch or debug registers.
InstructionAccurateScope scope(this);
DCHECK(AreSameSizeAndType(src0, src1, src2, src3));
DCHECK(size == src0.SizeInBytes());
// When pushing multiple registers, the store order is chosen such that
// Push(a, b) is equivalent to Push(a) followed by Push(b).
switch (count) {
case 1:
DCHECK(src1.IsNone() && src2.IsNone() && src3.IsNone());
str(src0, MemOperand(StackPointer(), -1 * size, PreIndex));
break;
case 2:
DCHECK(src2.IsNone() && src3.IsNone());
stp(src1, src0, MemOperand(StackPointer(), -2 * size, PreIndex));
break;
case 3:
DCHECK(src3.IsNone());
stp(src2, src1, MemOperand(StackPointer(), -3 * size, PreIndex));
str(src0, MemOperand(StackPointer(), 2 * size));
break;
case 4:
// Skip over 4 * size, then fill in the gap. This allows four W registers
// to be pushed using csp, whilst maintaining 16-byte alignment for csp
// at all times.
stp(src3, src2, MemOperand(StackPointer(), -4 * size, PreIndex));
stp(src1, src0, MemOperand(StackPointer(), 2 * size));
break;
default:
UNREACHABLE();
}
}
void MacroAssembler::PopHelper(int count, int size,
const CPURegister& dst0,
const CPURegister& dst1,
const CPURegister& dst2,
const CPURegister& dst3) {
// Ensure that we don't unintentially modify scratch or debug registers.
InstructionAccurateScope scope(this);
DCHECK(AreSameSizeAndType(dst0, dst1, dst2, dst3));
DCHECK(size == dst0.SizeInBytes());
// When popping multiple registers, the load order is chosen such that
// Pop(a, b) is equivalent to Pop(a) followed by Pop(b).
switch (count) {
case 1:
DCHECK(dst1.IsNone() && dst2.IsNone() && dst3.IsNone());
ldr(dst0, MemOperand(StackPointer(), 1 * size, PostIndex));
break;
case 2:
DCHECK(dst2.IsNone() && dst3.IsNone());
ldp(dst0, dst1, MemOperand(StackPointer(), 2 * size, PostIndex));
break;
case 3:
DCHECK(dst3.IsNone());
ldr(dst2, MemOperand(StackPointer(), 2 * size));
ldp(dst0, dst1, MemOperand(StackPointer(), 3 * size, PostIndex));
break;
case 4:
// Load the higher addresses first, then load the lower addresses and
// skip the whole block in the second instruction. This allows four W
// registers to be popped using csp, whilst maintaining 16-byte alignment
// for csp at all times.
ldp(dst2, dst3, MemOperand(StackPointer(), 2 * size));
ldp(dst0, dst1, MemOperand(StackPointer(), 4 * size, PostIndex));
break;
default:
UNREACHABLE();
}
}
void MacroAssembler::PushPreamble(Operand total_size) {
if (csp.Is(StackPointer())) {
// If the current stack pointer is csp, then it must be aligned to 16 bytes
// on entry and the total size of the specified registers must also be a
// multiple of 16 bytes.
if (total_size.IsImmediate()) {
DCHECK((total_size.ImmediateValue() % 16) == 0);
}
// Don't check access size for non-immediate sizes. It's difficult to do
// well, and it will be caught by hardware (or the simulator) anyway.
} else {
// Even if the current stack pointer is not the system stack pointer (csp),
// the system stack pointer will still be modified in order to comply with
// ABI rules about accessing memory below the system stack pointer.
BumpSystemStackPointer(total_size);
}
}
void MacroAssembler::PopPostamble(Operand total_size) {
if (csp.Is(StackPointer())) {
// If the current stack pointer is csp, then it must be aligned to 16 bytes
// on entry and the total size of the specified registers must also be a
// multiple of 16 bytes.
if (total_size.IsImmediate()) {
DCHECK((total_size.ImmediateValue() % 16) == 0);
}
// Don't check access size for non-immediate sizes. It's difficult to do
// well, and it will be caught by hardware (or the simulator) anyway.
} else if (emit_debug_code()) {
// It is safe to leave csp where it is when unwinding the JavaScript stack,
// but if we keep it matching StackPointer, the simulator can detect memory
// accesses in the now-free part of the stack.
SyncSystemStackPointer();
}
}
void MacroAssembler::Poke(const CPURegister& src, const Operand& offset) {
if (offset.IsImmediate()) {
DCHECK(offset.ImmediateValue() >= 0);
} else if (emit_debug_code()) {
Cmp(xzr, offset);
Check(le, kStackAccessBelowStackPointer);
}
Str(src, MemOperand(StackPointer(), offset));
}
void MacroAssembler::Peek(const CPURegister& dst, const Operand& offset) {
if (offset.IsImmediate()) {
DCHECK(offset.ImmediateValue() >= 0);
} else if (emit_debug_code()) {
Cmp(xzr, offset);
Check(le, kStackAccessBelowStackPointer);
}
Ldr(dst, MemOperand(StackPointer(), offset));
}
void MacroAssembler::PokePair(const CPURegister& src1,
const CPURegister& src2,
int offset) {
DCHECK(AreSameSizeAndType(src1, src2));
DCHECK((offset >= 0) && ((offset % src1.SizeInBytes()) == 0));
Stp(src1, src2, MemOperand(StackPointer(), offset));
}
void MacroAssembler::PeekPair(const CPURegister& dst1,
const CPURegister& dst2,
int offset) {
DCHECK(AreSameSizeAndType(dst1, dst2));
DCHECK((offset >= 0) && ((offset % dst1.SizeInBytes()) == 0));
Ldp(dst1, dst2, MemOperand(StackPointer(), offset));
}
void MacroAssembler::PushCalleeSavedRegisters() {
// Ensure that the macro-assembler doesn't use any scratch registers.
InstructionAccurateScope scope(this);
// This method must not be called unless the current stack pointer is the
// system stack pointer (csp).
DCHECK(csp.Is(StackPointer()));
MemOperand tos(csp, -2 * kXRegSize, PreIndex);
stp(d14, d15, tos);
stp(d12, d13, tos);
stp(d10, d11, tos);
stp(d8, d9, tos);
stp(x29, x30, tos);
stp(x27, x28, tos); // x28 = jssp
stp(x25, x26, tos);
stp(x23, x24, tos);
stp(x21, x22, tos);
stp(x19, x20, tos);
}
void MacroAssembler::PopCalleeSavedRegisters() {
// Ensure that the macro-assembler doesn't use any scratch registers.
InstructionAccurateScope scope(this);
// This method must not be called unless the current stack pointer is the
// system stack pointer (csp).
DCHECK(csp.Is(StackPointer()));
MemOperand tos(csp, 2 * kXRegSize, PostIndex);
ldp(x19, x20, tos);
ldp(x21, x22, tos);
ldp(x23, x24, tos);
ldp(x25, x26, tos);
ldp(x27, x28, tos); // x28 = jssp
ldp(x29, x30, tos);
ldp(d8, d9, tos);
ldp(d10, d11, tos);
ldp(d12, d13, tos);
ldp(d14, d15, tos);
}
void MacroAssembler::AssertStackConsistency() {
// Avoid emitting code when !use_real_abort() since non-real aborts cause too
// much code to be generated.
if (emit_debug_code() && use_real_aborts()) {
if (csp.Is(StackPointer())) {
// Always check the alignment of csp if ALWAYS_ALIGN_CSP is true. We
// can't check the alignment of csp without using a scratch register (or
// clobbering the flags), but the processor (or simulator) will abort if
// it is not properly aligned during a load.
ldr(xzr, MemOperand(csp, 0));
}
if (FLAG_enable_slow_asserts && !csp.Is(StackPointer())) {
Label ok;
// Check that csp <= StackPointer(), preserving all registers and NZCV.
sub(StackPointer(), csp, StackPointer());
cbz(StackPointer(), &ok); // Ok if csp == StackPointer().
tbnz(StackPointer(), kXSignBit, &ok); // Ok if csp < StackPointer().
// Avoid generating AssertStackConsistency checks for the Push in Abort.
{ DontEmitDebugCodeScope dont_emit_debug_code_scope(this);
Abort(kTheCurrentStackPointerIsBelowCsp);
}
bind(&ok);
// Restore StackPointer().
sub(StackPointer(), csp, StackPointer());
}
}
}
void MacroAssembler::AssertFPCRState(Register fpcr) {
if (emit_debug_code()) {
Label unexpected_mode, done;
UseScratchRegisterScope temps(this);
if (fpcr.IsNone()) {
fpcr = temps.AcquireX();
Mrs(fpcr, FPCR);
}
// Settings overridden by ConfiugreFPCR():
// - Assert that default-NaN mode is set.
Tbz(fpcr, DN_offset, &unexpected_mode);
// Settings left to their default values:
// - Assert that flush-to-zero is not set.
Tbnz(fpcr, FZ_offset, &unexpected_mode);
// - Assert that the rounding mode is nearest-with-ties-to-even.
STATIC_ASSERT(FPTieEven == 0);
Tst(fpcr, RMode_mask);
B(eq, &done);
Bind(&unexpected_mode);
Abort(kUnexpectedFPCRMode);
Bind(&done);
}
}
void MacroAssembler::ConfigureFPCR() {
UseScratchRegisterScope temps(this);
Register fpcr = temps.AcquireX();
Mrs(fpcr, FPCR);
// If necessary, enable default-NaN mode. The default values of the other FPCR
// options should be suitable, and AssertFPCRState will verify that.
Label no_write_required;
Tbnz(fpcr, DN_offset, &no_write_required);
Orr(fpcr, fpcr, DN_mask);
Msr(FPCR, fpcr);
Bind(&no_write_required);
AssertFPCRState(fpcr);
}
void MacroAssembler::CanonicalizeNaN(const FPRegister& dst,
const FPRegister& src) {
AssertFPCRState();
// With DN=1 and RMode=FPTieEven, subtracting 0.0 preserves all inputs except
// for NaNs, which become the default NaN. We use fsub rather than fadd
// because sub preserves -0.0 inputs: -0.0 + 0.0 = 0.0, but -0.0 - 0.0 = -0.0.
Fsub(dst, src, fp_zero);
}
void MacroAssembler::LoadRoot(CPURegister destination,
Heap::RootListIndex index) {
// TODO(jbramley): Most root values are constants, and can be synthesized
// without a load. Refer to the ARM back end for details.
Ldr(destination, MemOperand(root, index << kPointerSizeLog2));
}
void MacroAssembler::StoreRoot(Register source,
Heap::RootListIndex index) {
Str(source, MemOperand(root, index << kPointerSizeLog2));
}
void MacroAssembler::LoadTrueFalseRoots(Register true_root,
Register false_root) {
STATIC_ASSERT((Heap::kTrueValueRootIndex + 1) == Heap::kFalseValueRootIndex);
Ldp(true_root, false_root,
MemOperand(root, Heap::kTrueValueRootIndex << kPointerSizeLog2));
}
void MacroAssembler::LoadHeapObject(Register result,
Handle<HeapObject> object) {
AllowDeferredHandleDereference using_raw_address;
if (isolate()->heap()->InNewSpace(*object)) {
Handle<Cell> cell = isolate()->factory()->NewCell(object);
Mov(result, Operand(cell));
Ldr(result, FieldMemOperand(result, Cell::kValueOffset));
} else {
Mov(result, Operand(object));
}
}
void MacroAssembler::LoadInstanceDescriptors(Register map,
Register descriptors) {
Ldr(descriptors, FieldMemOperand(map, Map::kDescriptorsOffset));
}
void MacroAssembler::NumberOfOwnDescriptors(Register dst, Register map) {
Ldr(dst, FieldMemOperand(map, Map::kBitField3Offset));
DecodeField<Map::NumberOfOwnDescriptorsBits>(dst);
}
void MacroAssembler::EnumLengthUntagged(Register dst, Register map) {
STATIC_ASSERT(Map::EnumLengthBits::kShift == 0);
Ldrsw(dst, FieldMemOperand(map, Map::kBitField3Offset));
And(dst, dst, Map::EnumLengthBits::kMask);
}
void MacroAssembler::EnumLengthSmi(Register dst, Register map) {
EnumLengthUntagged(dst, map);
SmiTag(dst, dst);
}
void MacroAssembler::CheckEnumCache(Register object,
Register null_value,
Register scratch0,
Register scratch1,
Register scratch2,
Register scratch3,
Label* call_runtime) {
DCHECK(!AreAliased(object, null_value, scratch0, scratch1, scratch2,
scratch3));
Register empty_fixed_array_value = scratch0;
Register current_object = scratch1;
LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
Label next, start;
Mov(current_object, object);
// Check if the enum length field is properly initialized, indicating that
// there is an enum cache.
Register map = scratch2;
Register enum_length = scratch3;
Ldr(map, FieldMemOperand(current_object, HeapObject::kMapOffset));
EnumLengthUntagged(enum_length, map);
Cmp(enum_length, kInvalidEnumCacheSentinel);
B(eq, call_runtime);
B(&start);
Bind(&next);
Ldr(map, FieldMemOperand(current_object, HeapObject::kMapOffset));
// For all objects but the receiver, check that the cache is empty.
EnumLengthUntagged(enum_length, map);
Cbnz(enum_length, call_runtime);
Bind(&start);
// Check that there are no elements. Register current_object contains the
// current JS object we've reached through the prototype chain.
Label no_elements;
Ldr(current_object, FieldMemOperand(current_object,
JSObject::kElementsOffset));
Cmp(current_object, empty_fixed_array_value);
B(eq, &no_elements);
// Second chance, the object may be using the empty slow element dictionary.
CompareRoot(current_object, Heap::kEmptySlowElementDictionaryRootIndex);
B(ne, call_runtime);
Bind(&no_elements);
Ldr(current_object, FieldMemOperand(map, Map::kPrototypeOffset));
Cmp(current_object, null_value);
B(ne, &next);
}
void MacroAssembler::TestJSArrayForAllocationMemento(Register receiver,
Register scratch1,
Register scratch2,
Label* no_memento_found) {
ExternalReference new_space_start =
ExternalReference::new_space_start(isolate());
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address(isolate());
Add(scratch1, receiver,
JSArray::kSize + AllocationMemento::kSize - kHeapObjectTag);
Cmp(scratch1, new_space_start);
B(lt, no_memento_found);
Mov(scratch2, new_space_allocation_top);
Ldr(scratch2, MemOperand(scratch2));
Cmp(scratch1, scratch2);
B(gt, no_memento_found);
Ldr(scratch1, MemOperand(scratch1, -AllocationMemento::kSize));
Cmp(scratch1,
Operand(isolate()->factory()->allocation_memento_map()));
}
void MacroAssembler::JumpToHandlerEntry(Register exception,
Register object,
Register state,
Register scratch1,
Register scratch2) {
// Handler expects argument in x0.
DCHECK(exception.Is(x0));
// Compute the handler entry address and jump to it. The handler table is
// a fixed array of (smi-tagged) code offsets.
Ldr(scratch1, FieldMemOperand(object, Code::kHandlerTableOffset));
Add(scratch1, scratch1, FixedArray::kHeaderSize - kHeapObjectTag);
STATIC_ASSERT(StackHandler::kKindWidth < kPointerSizeLog2);
Lsr(scratch2, state, StackHandler::kKindWidth);
Ldr(scratch2, MemOperand(scratch1, scratch2, LSL, kPointerSizeLog2));
Add(scratch1, object, Code::kHeaderSize - kHeapObjectTag);
Add(scratch1, scratch1, Operand::UntagSmi(scratch2));
Br(scratch1);
}
void MacroAssembler::InNewSpace(Register object,
Condition cond,
Label* branch) {
DCHECK(cond == eq || cond == ne);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
And(temp, object, ExternalReference::new_space_mask(isolate()));
Cmp(temp, ExternalReference::new_space_start(isolate()));
B(cond, branch);
}
void MacroAssembler::Throw(Register value,
Register scratch1,
Register scratch2,
Register scratch3,
Register scratch4) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
// The handler expects the exception in x0.
DCHECK(value.Is(x0));
// Drop the stack pointer to the top of the top handler.
DCHECK(jssp.Is(StackPointer()));
Mov(scratch1, Operand(ExternalReference(Isolate::kHandlerAddress,
isolate())));
Ldr(jssp, MemOperand(scratch1));
// Restore the next handler.
Pop(scratch2);
Str(scratch2, MemOperand(scratch1));
// Get the code object and state. Restore the context and frame pointer.
Register object = scratch1;
Register state = scratch2;
Pop(object, state, cp, fp);
// If the handler is a JS frame, restore the context to the frame.
// (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
// or cp.
Label not_js_frame;
Cbz(cp, &not_js_frame);
Str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
Bind(&not_js_frame);
JumpToHandlerEntry(value, object, state, scratch3, scratch4);
}
void MacroAssembler::ThrowUncatchable(Register value,
Register scratch1,
Register scratch2,
Register scratch3,
Register scratch4) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
// The handler expects the exception in x0.
DCHECK(value.Is(x0));
// Drop the stack pointer to the top of the top stack handler.
DCHECK(jssp.Is(StackPointer()));
Mov(scratch1, Operand(ExternalReference(Isolate::kHandlerAddress,
isolate())));
Ldr(jssp, MemOperand(scratch1));
// Unwind the handlers until the ENTRY handler is found.
Label fetch_next, check_kind;
B(&check_kind);
Bind(&fetch_next);
Peek(jssp, StackHandlerConstants::kNextOffset);
Bind(&check_kind);
STATIC_ASSERT(StackHandler::JS_ENTRY == 0);
Peek(scratch2, StackHandlerConstants::kStateOffset);
TestAndBranchIfAnySet(scratch2, StackHandler::KindField::kMask, &fetch_next);
// Set the top handler address to next handler past the top ENTRY handler.
Pop(scratch2);
Str(scratch2, MemOperand(scratch1));
// Get the code object and state. Clear the context and frame pointer (0 was
// saved in the handler).
Register object = scratch1;
Register state = scratch2;
Pop(object, state, cp, fp);
JumpToHandlerEntry(value, object, state, scratch3, scratch4);
}
void MacroAssembler::AssertSmi(Register object, BailoutReason reason) {
if (emit_debug_code()) {
STATIC_ASSERT(kSmiTag == 0);
Tst(object, kSmiTagMask);
Check(eq, reason);
}
}
void MacroAssembler::AssertNotSmi(Register object, BailoutReason reason) {
if (emit_debug_code()) {
STATIC_ASSERT(kSmiTag == 0);
Tst(object, kSmiTagMask);
Check(ne, reason);
}
}
void MacroAssembler::AssertName(Register object) {
if (emit_debug_code()) {
AssertNotSmi(object, kOperandIsASmiAndNotAName);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
CompareInstanceType(temp, temp, LAST_NAME_TYPE);
Check(ls, kOperandIsNotAName);
}
}
void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
Register scratch) {
if (emit_debug_code()) {
Label done_checking;
AssertNotSmi(object);
JumpIfRoot(object, Heap::kUndefinedValueRootIndex, &done_checking);
Ldr(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
CompareRoot(scratch, Heap::kAllocationSiteMapRootIndex);
Assert(eq, kExpectedUndefinedOrCell);
Bind(&done_checking);
}
}
void MacroAssembler::AssertString(Register object) {
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
STATIC_ASSERT(kSmiTag == 0);
Tst(object, kSmiTagMask);
Check(ne, kOperandIsASmiAndNotAString);
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
CompareInstanceType(temp, temp, FIRST_NONSTRING_TYPE);
Check(lo, kOperandIsNotAString);
}
}
void MacroAssembler::CallStub(CodeStub* stub, TypeFeedbackId ast_id) {
DCHECK(AllowThisStubCall(stub)); // Stub calls are not allowed in some stubs.
Call(stub->GetCode(), RelocInfo::CODE_TARGET, ast_id);
}
void MacroAssembler::TailCallStub(CodeStub* stub) {
Jump(stub->GetCode(), RelocInfo::CODE_TARGET);
}
void MacroAssembler::CallRuntime(const Runtime::Function* f,
int num_arguments,
SaveFPRegsMode save_doubles) {
// All arguments must be on the stack before this function is called.
// x0 holds the return value after the call.
// Check that the number of arguments matches what the function expects.
// If f->nargs is -1, the function can accept a variable number of arguments.
CHECK(f->nargs < 0 || f->nargs == num_arguments);
// Place the necessary arguments.
Mov(x0, num_arguments);
Mov(x1, ExternalReference(f, isolate()));
CEntryStub stub(isolate(), 1, save_doubles);
CallStub(&stub);
}
static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
return ref0.address() - ref1.address();
}
void MacroAssembler::CallApiFunctionAndReturn(
Register function_address,
ExternalReference thunk_ref,
int stack_space,
int spill_offset,
MemOperand return_value_operand,
MemOperand* context_restore_operand) {
ASM_LOCATION("CallApiFunctionAndReturn");
ExternalReference next_address =
ExternalReference::handle_scope_next_address(isolate());
const int kNextOffset = 0;
const int kLimitOffset = AddressOffset(
ExternalReference::handle_scope_limit_address(isolate()),
next_address);
const int kLevelOffset = AddressOffset(
ExternalReference::handle_scope_level_address(isolate()),
next_address);
DCHECK(function_address.is(x1) || function_address.is(x2));
Label profiler_disabled;
Label end_profiler_check;
Mov(x10, ExternalReference::is_profiling_address(isolate()));
Ldrb(w10, MemOperand(x10));
Cbz(w10, &profiler_disabled);
Mov(x3, thunk_ref);
B(&end_profiler_check);
Bind(&profiler_disabled);
Mov(x3, function_address);
Bind(&end_profiler_check);
// Save the callee-save registers we are going to use.
// TODO(all): Is this necessary? ARM doesn't do it.
STATIC_ASSERT(kCallApiFunctionSpillSpace == 4);
Poke(x19, (spill_offset + 0) * kXRegSize);
Poke(x20, (spill_offset + 1) * kXRegSize);
Poke(x21, (spill_offset + 2) * kXRegSize);
Poke(x22, (spill_offset + 3) * kXRegSize);
// Allocate HandleScope in callee-save registers.
// We will need to restore the HandleScope after the call to the API function,
// by allocating it in callee-save registers they will be preserved by C code.
Register handle_scope_base = x22;
Register next_address_reg = x19;
Register limit_reg = x20;
Register level_reg = w21;
Mov(handle_scope_base, next_address);
Ldr(next_address_reg, MemOperand(handle_scope_base, kNextOffset));
Ldr(limit_reg, MemOperand(handle_scope_base, kLimitOffset));
Ldr(level_reg, MemOperand(handle_scope_base, kLevelOffset));
Add(level_reg, level_reg, 1);
Str(level_reg, MemOperand(handle_scope_base, kLevelOffset));
if (FLAG_log_timer_events) {
FrameScope frame(this, StackFrame::MANUAL);
PushSafepointRegisters();
Mov(x0, ExternalReference::isolate_address(isolate()));
CallCFunction(ExternalReference::log_enter_external_function(isolate()), 1);
PopSafepointRegisters();
}
// Native call returns to the DirectCEntry stub which redirects to the
// return address pushed on stack (could have moved after GC).
// DirectCEntry stub itself is generated early and never moves.
DirectCEntryStub stub(isolate());
stub.GenerateCall(this, x3);
if (FLAG_log_timer_events) {
FrameScope frame(this, StackFrame::MANUAL);
PushSafepointRegisters();
Mov(x0, ExternalReference::isolate_address(isolate()));
CallCFunction(ExternalReference::log_leave_external_function(isolate()), 1);
PopSafepointRegisters();
}
Label promote_scheduled_exception;
Label exception_handled;
Label delete_allocated_handles;
Label leave_exit_frame;
Label return_value_loaded;
// Load value from ReturnValue.
Ldr(x0, return_value_operand);
Bind(&return_value_loaded);
// No more valid handles (the result handle was the last one). Restore
// previous handle scope.
Str(next_address_reg, MemOperand(handle_scope_base, kNextOffset));
if (emit_debug_code()) {
Ldr(w1, MemOperand(handle_scope_base, kLevelOffset));
Cmp(w1, level_reg);
Check(eq, kUnexpectedLevelAfterReturnFromApiCall);
}
Sub(level_reg, level_reg, 1);
Str(level_reg, MemOperand(handle_scope_base, kLevelOffset));
Ldr(x1, MemOperand(handle_scope_base, kLimitOffset));
Cmp(limit_reg, x1);
B(ne, &delete_allocated_handles);
Bind(&leave_exit_frame);
// Restore callee-saved registers.
Peek(x19, (spill_offset + 0) * kXRegSize);
Peek(x20, (spill_offset + 1) * kXRegSize);
Peek(x21, (spill_offset + 2) * kXRegSize);
Peek(x22, (spill_offset + 3) * kXRegSize);
// Check if the function scheduled an exception.
Mov(x5, ExternalReference::scheduled_exception_address(isolate()));
Ldr(x5, MemOperand(x5));
JumpIfNotRoot(x5, Heap::kTheHoleValueRootIndex, &promote_scheduled_exception);
Bind(&exception_handled);
bool restore_context = context_restore_operand != NULL;
if (restore_context) {
Ldr(cp, *context_restore_operand);
}
LeaveExitFrame(false, x1, !restore_context);
Drop(stack_space);
Ret();
Bind(&promote_scheduled_exception);
{
FrameScope frame(this, StackFrame::INTERNAL);
CallExternalReference(
ExternalReference(
Runtime::kPromoteScheduledException, isolate()), 0);
}
B(&exception_handled);
// HandleScope limit has changed. Delete allocated extensions.
Bind(&delete_allocated_handles);
Str(limit_reg, MemOperand(handle_scope_base, kLimitOffset));
// Save the return value in a callee-save register.
Register saved_result = x19;
Mov(saved_result, x0);
Mov(x0, ExternalReference::isolate_address(isolate()));
CallCFunction(
ExternalReference::delete_handle_scope_extensions(isolate()), 1);
Mov(x0, saved_result);
B(&leave_exit_frame);
}
void MacroAssembler::CallExternalReference(const ExternalReference& ext,
int num_arguments) {
Mov(x0, num_arguments);
Mov(x1, ext);
CEntryStub stub(isolate(), 1);
CallStub(&stub);
}
void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin) {
Mov(x1, builtin);
CEntryStub stub(isolate(), 1);
Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
}
void MacroAssembler::GetBuiltinFunction(Register target,
Builtins::JavaScript id) {
// Load the builtins object into target register.
Ldr(target, GlobalObjectMemOperand());
Ldr(target, FieldMemOperand(target, GlobalObject::kBuiltinsOffset));
// Load the JavaScript builtin function from the builtins object.
Ldr(target, FieldMemOperand(target,
JSBuiltinsObject::OffsetOfFunctionWithId(id)));
}
void MacroAssembler::GetBuiltinEntry(Register target,
Register function,
Builtins::JavaScript id) {
DCHECK(!AreAliased(target, function));
GetBuiltinFunction(function, id);
// Load the code entry point from the builtins object.
Ldr(target, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
}
void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
InvokeFlag flag,
const CallWrapper& call_wrapper) {
ASM_LOCATION("MacroAssembler::InvokeBuiltin");
// You can't call a builtin without a valid frame.
DCHECK(flag == JUMP_FUNCTION || has_frame());
// Get the builtin entry in x2 and setup the function object in x1.
GetBuiltinEntry(x2, x1, id);
if (flag == CALL_FUNCTION) {
call_wrapper.BeforeCall(CallSize(x2));
Call(x2);
call_wrapper.AfterCall();
} else {
DCHECK(flag == JUMP_FUNCTION);
Jump(x2);
}
}
void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
int num_arguments,
int result_size) {
// TODO(1236192): Most runtime routines don't need the number of
// arguments passed in because it is constant. At some point we
// should remove this need and make the runtime routine entry code
// smarter.
Mov(x0, num_arguments);
JumpToExternalReference(ext);
}
void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
int num_arguments,
int result_size) {
TailCallExternalReference(ExternalReference(fid, isolate()),
num_arguments,
result_size);
}
void MacroAssembler::InitializeNewString(Register string,
Register length,
Heap::RootListIndex map_index,
Register scratch1,
Register scratch2) {
DCHECK(!AreAliased(string, length, scratch1, scratch2));
LoadRoot(scratch2, map_index);
SmiTag(scratch1, length);
Str(scratch2, FieldMemOperand(string, HeapObject::kMapOffset));
Mov(scratch2, String::kEmptyHashField);
Str(scratch1, FieldMemOperand(string, String::kLengthOffset));
Str(scratch2, FieldMemOperand(string, String::kHashFieldOffset));
}
int MacroAssembler::ActivationFrameAlignment() {
#if V8_HOST_ARCH_ARM64
// Running on the real platform. Use the alignment as mandated by the local
// environment.
// Note: This will break if we ever start generating snapshots on one ARM
// platform for another ARM platform with a different alignment.
return base::OS::ActivationFrameAlignment();
#else // V8_HOST_ARCH_ARM64
// If we are using the simulator then we should always align to the expected
// alignment. As the simulator is used to generate snapshots we do not know
// if the target platform will need alignment, so this is controlled from a
// flag.
return FLAG_sim_stack_alignment;
#endif // V8_HOST_ARCH_ARM64
}
void MacroAssembler::CallCFunction(ExternalReference function,
int num_of_reg_args) {
CallCFunction(function, num_of_reg_args, 0);
}
void MacroAssembler::CallCFunction(ExternalReference function,
int num_of_reg_args,
int num_of_double_args) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Mov(temp, function);
CallCFunction(temp, num_of_reg_args, num_of_double_args);
}
void MacroAssembler::CallCFunction(Register function,
int num_of_reg_args,
int num_of_double_args) {
DCHECK(has_frame());
// We can pass 8 integer arguments in registers. If we need to pass more than
// that, we'll need to implement support for passing them on the stack.
DCHECK(num_of_reg_args <= 8);
// If we're passing doubles, we're limited to the following prototypes
// (defined by ExternalReference::Type):
// BUILTIN_COMPARE_CALL: int f(double, double)
// BUILTIN_FP_FP_CALL: double f(double, double)
// BUILTIN_FP_CALL: double f(double)
// BUILTIN_FP_INT_CALL: double f(double, int)
if (num_of_double_args > 0) {
DCHECK(num_of_reg_args <= 1);
DCHECK((num_of_double_args + num_of_reg_args) <= 2);
}
// If the stack pointer is not csp, we need to derive an aligned csp from the
// current stack pointer.
const Register old_stack_pointer = StackPointer();
if (!csp.Is(old_stack_pointer)) {
AssertStackConsistency();
int sp_alignment = ActivationFrameAlignment();
// The ABI mandates at least 16-byte alignment.
DCHECK(sp_alignment >= 16);
DCHECK(base::bits::IsPowerOfTwo32(sp_alignment));
// The current stack pointer is a callee saved register, and is preserved
// across the call.
DCHECK(kCalleeSaved.IncludesAliasOf(old_stack_pointer));
// Align and synchronize the system stack pointer with jssp.
Bic(csp, old_stack_pointer, sp_alignment - 1);
SetStackPointer(csp);
}
// Call directly. The function called cannot cause a GC, or allow preemption,
// so the return address in the link register stays correct.
Call(function);
if (!csp.Is(old_stack_pointer)) {
if (emit_debug_code()) {
// Because the stack pointer must be aligned on a 16-byte boundary, the
// aligned csp can be up to 12 bytes below the jssp. This is the case
// where we only pushed one W register on top of an aligned jssp.
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
DCHECK(ActivationFrameAlignment() == 16);
Sub(temp, csp, old_stack_pointer);
// We want temp <= 0 && temp >= -12.
Cmp(temp, 0);
Ccmp(temp, -12, NFlag, le);
Check(ge, kTheStackWasCorruptedByMacroAssemblerCall);
}
SetStackPointer(old_stack_pointer);
}
}
void MacroAssembler::Jump(Register target) {
Br(target);
}
void MacroAssembler::Jump(intptr_t target, RelocInfo::Mode rmode) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Mov(temp, Operand(target, rmode));
Br(temp);
}
void MacroAssembler::Jump(Address target, RelocInfo::Mode rmode) {
DCHECK(!RelocInfo::IsCodeTarget(rmode));
Jump(reinterpret_cast<intptr_t>(target), rmode);
}
void MacroAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode) {
DCHECK(RelocInfo::IsCodeTarget(rmode));
AllowDeferredHandleDereference embedding_raw_address;
Jump(reinterpret_cast<intptr_t>(code.location()), rmode);
}
void MacroAssembler::Call(Register target) {
BlockPoolsScope scope(this);
#ifdef DEBUG
Label start_call;
Bind(&start_call);
#endif
Blr(target);
#ifdef DEBUG
AssertSizeOfCodeGeneratedSince(&start_call, CallSize(target));
#endif
}
void MacroAssembler::Call(Label* target) {
BlockPoolsScope scope(this);
#ifdef DEBUG
Label start_call;
Bind(&start_call);
#endif
Bl(target);
#ifdef DEBUG
AssertSizeOfCodeGeneratedSince(&start_call, CallSize(target));
#endif
}
// MacroAssembler::CallSize is sensitive to changes in this function, as it
// requires to know how many instructions are used to branch to the target.
void MacroAssembler::Call(Address target, RelocInfo::Mode rmode) {
BlockPoolsScope scope(this);
#ifdef DEBUG
Label start_call;
Bind(&start_call);
#endif
// Statement positions are expected to be recorded when the target
// address is loaded.
positions_recorder()->WriteRecordedPositions();
// Addresses always have 64 bits, so we shouldn't encounter NONE32.
DCHECK(rmode != RelocInfo::NONE32);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
if (rmode == RelocInfo::NONE64) {
// Addresses are 48 bits so we never need to load the upper 16 bits.
uint64_t imm = reinterpret_cast<uint64_t>(target);
// If we don't use ARM tagged addresses, the 16 higher bits must be 0.
DCHECK(((imm >> 48) & 0xffff) == 0);
movz(temp, (imm >> 0) & 0xffff, 0);
movk(temp, (imm >> 16) & 0xffff, 16);
movk(temp, (imm >> 32) & 0xffff, 32);
} else {
Ldr(temp, Immediate(reinterpret_cast<intptr_t>(target), rmode));
}
Blr(temp);
#ifdef DEBUG
AssertSizeOfCodeGeneratedSince(&start_call, CallSize(target, rmode));
#endif
}
void MacroAssembler::Call(Handle<Code> code,
RelocInfo::Mode rmode,
TypeFeedbackId ast_id) {
#ifdef DEBUG
Label start_call;
Bind(&start_call);
#endif
if ((rmode == RelocInfo::CODE_TARGET) && (!ast_id.IsNone())) {
SetRecordedAstId(ast_id);
rmode = RelocInfo::CODE_TARGET_WITH_ID;
}
AllowDeferredHandleDereference embedding_raw_address;
Call(reinterpret_cast<Address>(code.location()), rmode);
#ifdef DEBUG
// Check the size of the code generated.
AssertSizeOfCodeGeneratedSince(&start_call, CallSize(code, rmode, ast_id));
#endif
}
int MacroAssembler::CallSize(Register target) {
USE(target);
return kInstructionSize;
}
int MacroAssembler::CallSize(Label* target) {
USE(target);
return kInstructionSize;
}
int MacroAssembler::CallSize(Address target, RelocInfo::Mode rmode) {
USE(target);
// Addresses always have 64 bits, so we shouldn't encounter NONE32.
DCHECK(rmode != RelocInfo::NONE32);
if (rmode == RelocInfo::NONE64) {
return kCallSizeWithoutRelocation;
} else {
return kCallSizeWithRelocation;
}
}
int MacroAssembler::CallSize(Handle<Code> code,
RelocInfo::Mode rmode,
TypeFeedbackId ast_id) {
USE(code);
USE(ast_id);
// Addresses always have 64 bits, so we shouldn't encounter NONE32.
DCHECK(rmode != RelocInfo::NONE32);
if (rmode == RelocInfo::NONE64) {
return kCallSizeWithoutRelocation;
} else {
return kCallSizeWithRelocation;
}
}
void MacroAssembler::JumpIfHeapNumber(Register object, Label* on_heap_number,
SmiCheckType smi_check_type) {
Label on_not_heap_number;
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(object, &on_not_heap_number);
}
AssertNotSmi(object);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
JumpIfRoot(temp, Heap::kHeapNumberMapRootIndex, on_heap_number);
Bind(&on_not_heap_number);
}
void MacroAssembler::JumpIfNotHeapNumber(Register object,
Label* on_not_heap_number,
SmiCheckType smi_check_type) {
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(object, on_not_heap_number);
}
AssertNotSmi(object);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
JumpIfNotRoot(temp, Heap::kHeapNumberMapRootIndex, on_not_heap_number);
}
void MacroAssembler::LookupNumberStringCache(Register object,
Register result,
Register scratch1,
Register scratch2,
Register scratch3,
Label* not_found) {
DCHECK(!AreAliased(object, result, scratch1, scratch2, scratch3));
// Use of registers. Register result is used as a temporary.
Register number_string_cache = result;
Register mask = scratch3;
// Load the number string cache.
LoadRoot(number_string_cache, Heap::kNumberStringCacheRootIndex);
// Make the hash mask from the length of the number string cache. It
// contains two elements (number and string) for each cache entry.
Ldrsw(mask, UntagSmiFieldMemOperand(number_string_cache,
FixedArray::kLengthOffset));
Asr(mask, mask, 1); // Divide length by two.
Sub(mask, mask, 1); // Make mask.
// Calculate the entry in the number string cache. The hash value in the
// number string cache for smis is just the smi value, and the hash for
// doubles is the xor of the upper and lower words. See
// Heap::GetNumberStringCache.
Label is_smi;
Label load_result_from_cache;
JumpIfSmi(object, &is_smi);
JumpIfNotHeapNumber(object, not_found);
STATIC_ASSERT(kDoubleSize == (kWRegSize * 2));
Add(scratch1, object, HeapNumber::kValueOffset - kHeapObjectTag);
Ldp(scratch1.W(), scratch2.W(), MemOperand(scratch1));
Eor(scratch1, scratch1, scratch2);
And(scratch1, scratch1, mask);
// Calculate address of entry in string cache: each entry consists of two
// pointer sized fields.
Add(scratch1, number_string_cache,
Operand(scratch1, LSL, kPointerSizeLog2 + 1));
Register probe = mask;
Ldr(probe, FieldMemOperand(scratch1, FixedArray::kHeaderSize));
JumpIfSmi(probe, not_found);
Ldr(d0, FieldMemOperand(object, HeapNumber::kValueOffset));
Ldr(d1, FieldMemOperand(probe, HeapNumber::kValueOffset));
Fcmp(d0, d1);
B(ne, not_found);
B(&load_result_from_cache);
Bind(&is_smi);
Register scratch = scratch1;
And(scratch, mask, Operand::UntagSmi(object));
// Calculate address of entry in string cache: each entry consists
// of two pointer sized fields.
Add(scratch, number_string_cache,
Operand(scratch, LSL, kPointerSizeLog2 + 1));
// Check if the entry is the smi we are looking for.
Ldr(probe, FieldMemOperand(scratch, FixedArray::kHeaderSize));
Cmp(object, probe);
B(ne, not_found);
// Get the result from the cache.
Bind(&load_result_from_cache);
Ldr(result, FieldMemOperand(scratch, FixedArray::kHeaderSize + kPointerSize));
IncrementCounter(isolate()->counters()->number_to_string_native(), 1,
scratch1, scratch2);
}
void MacroAssembler::TryRepresentDoubleAsInt(Register as_int,
FPRegister value,
FPRegister scratch_d,
Label* on_successful_conversion,
Label* on_failed_conversion) {
// Convert to an int and back again, then compare with the original value.
Fcvtzs(as_int, value);
Scvtf(scratch_d, as_int);
Fcmp(value, scratch_d);
if (on_successful_conversion) {
B(on_successful_conversion, eq);
}
if (on_failed_conversion) {
B(on_failed_conversion, ne);
}
}
void MacroAssembler::TestForMinusZero(DoubleRegister input) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
// Floating point -0.0 is kMinInt as an integer, so subtracting 1 (cmp) will
// cause overflow.
Fmov(temp, input);
Cmp(temp, 1);
}
void MacroAssembler::JumpIfMinusZero(DoubleRegister input,
Label* on_negative_zero) {
TestForMinusZero(input);
B(vs, on_negative_zero);
}
void MacroAssembler::JumpIfMinusZero(Register input,
Label* on_negative_zero) {
DCHECK(input.Is64Bits());
// Floating point value is in an integer register. Detect -0.0 by subtracting
// 1 (cmp), which will cause overflow.
Cmp(input, 1);
B(vs, on_negative_zero);
}
void MacroAssembler::ClampInt32ToUint8(Register output, Register input) {
// Clamp the value to [0..255].
Cmp(input.W(), Operand(input.W(), UXTB));
// If input < input & 0xff, it must be < 0, so saturate to 0.
Csel(output.W(), wzr, input.W(), lt);
// If input <= input & 0xff, it must be <= 255. Otherwise, saturate to 255.
Csel(output.W(), output.W(), 255, le);
}
void MacroAssembler::ClampInt32ToUint8(Register in_out) {
ClampInt32ToUint8(in_out, in_out);
}
void MacroAssembler::ClampDoubleToUint8(Register output,
DoubleRegister input,
DoubleRegister dbl_scratch) {
// This conversion follows the WebIDL "[Clamp]" rules for PIXEL types:
// - Inputs lower than 0 (including -infinity) produce 0.
// - Inputs higher than 255 (including +infinity) produce 255.
// Also, it seems that PIXEL types use round-to-nearest rather than
// round-towards-zero.
// Squash +infinity before the conversion, since Fcvtnu will normally
// convert it to 0.
Fmov(dbl_scratch, 255);
Fmin(dbl_scratch, dbl_scratch, input);
// Convert double to unsigned integer. Values less than zero become zero.
// Values greater than 255 have already been clamped to 255.
Fcvtnu(output, dbl_scratch);
}
void MacroAssembler::CopyFieldsLoopPairsHelper(Register dst,
Register src,
unsigned count,
Register scratch1,
Register scratch2,
Register scratch3,
Register scratch4,
Register scratch5) {
// Untag src and dst into scratch registers.
// Copy src->dst in a tight loop.
DCHECK(!AreAliased(dst, src,
scratch1, scratch2, scratch3, scratch4, scratch5));
DCHECK(count >= 2);
const Register& remaining = scratch3;
Mov(remaining, count / 2);
const Register& dst_untagged = scratch1;
const Register& src_untagged = scratch2;
Sub(dst_untagged, dst, kHeapObjectTag);
Sub(src_untagged, src, kHeapObjectTag);
// Copy fields in pairs.
Label loop;
Bind(&loop);
Ldp(scratch4, scratch5,
MemOperand(src_untagged, kXRegSize* 2, PostIndex));
Stp(scratch4, scratch5,
MemOperand(dst_untagged, kXRegSize* 2, PostIndex));
Sub(remaining, remaining, 1);
Cbnz(remaining, &loop);
// Handle the leftovers.
if (count & 1) {
Ldr(scratch4, MemOperand(src_untagged));
Str(scratch4, MemOperand(dst_untagged));
}
}
void MacroAssembler::CopyFieldsUnrolledPairsHelper(Register dst,
Register src,
unsigned count,
Register scratch1,
Register scratch2,
Register scratch3,
Register scratch4) {
// Untag src and dst into scratch registers.
// Copy src->dst in an unrolled loop.
DCHECK(!AreAliased(dst, src, scratch1, scratch2, scratch3, scratch4));
const Register& dst_untagged = scratch1;
const Register& src_untagged = scratch2;
sub(dst_untagged, dst, kHeapObjectTag);
sub(src_untagged, src, kHeapObjectTag);
// Copy fields in pairs.
for (unsigned i = 0; i < count / 2; i++) {
Ldp(scratch3, scratch4, MemOperand(src_untagged, kXRegSize * 2, PostIndex));
Stp(scratch3, scratch4, MemOperand(dst_untagged, kXRegSize * 2, PostIndex));
}
// Handle the leftovers.
if (count & 1) {
Ldr(scratch3, MemOperand(src_untagged));
Str(scratch3, MemOperand(dst_untagged));
}
}
void MacroAssembler::CopyFieldsUnrolledHelper(Register dst,
Register src,
unsigned count,
Register scratch1,
Register scratch2,
Register scratch3) {
// Untag src and dst into scratch registers.
// Copy src->dst in an unrolled loop.
DCHECK(!AreAliased(dst, src, scratch1, scratch2, scratch3));
const Register& dst_untagged = scratch1;
const Register& src_untagged = scratch2;
Sub(dst_untagged, dst, kHeapObjectTag);
Sub(src_untagged, src, kHeapObjectTag);
// Copy fields one by one.
for (unsigned i = 0; i < count; i++) {
Ldr(scratch3, MemOperand(src_untagged, kXRegSize, PostIndex));
Str(scratch3, MemOperand(dst_untagged, kXRegSize, PostIndex));
}
}
void MacroAssembler::CopyFields(Register dst, Register src, CPURegList temps,
unsigned count) {
// One of two methods is used:
//
// For high 'count' values where many scratch registers are available:
// Untag src and dst into scratch registers.
// Copy src->dst in a tight loop.
//
// For low 'count' values or where few scratch registers are available:
// Untag src and dst into scratch registers.
// Copy src->dst in an unrolled loop.
//
// In both cases, fields are copied in pairs if possible, and left-overs are
// handled separately.
DCHECK(!AreAliased(dst, src));
DCHECK(!temps.IncludesAliasOf(dst));
DCHECK(!temps.IncludesAliasOf(src));
DCHECK(!temps.IncludesAliasOf(xzr));
if (emit_debug_code()) {
Cmp(dst, src);
Check(ne, kTheSourceAndDestinationAreTheSame);
}
// The value of 'count' at which a loop will be generated (if there are
// enough scratch registers).
static const unsigned kLoopThreshold = 8;
UseScratchRegisterScope masm_temps(this);
if ((temps.Count() >= 3) && (count >= kLoopThreshold)) {
CopyFieldsLoopPairsHelper(dst, src, count,
Register(temps.PopLowestIndex()),
Register(temps.PopLowestIndex()),
Register(temps.PopLowestIndex()),
masm_temps.AcquireX(),
masm_temps.AcquireX());
} else if (temps.Count() >= 2) {
CopyFieldsUnrolledPairsHelper(dst, src, count,
Register(temps.PopLowestIndex()),
Register(temps.PopLowestIndex()),
masm_temps.AcquireX(),
masm_temps.AcquireX());
} else if (temps.Count() == 1) {
CopyFieldsUnrolledHelper(dst, src, count,
Register(temps.PopLowestIndex()),
masm_temps.AcquireX(),
masm_temps.AcquireX());
} else {
UNREACHABLE();
}
}
void MacroAssembler::CopyBytes(Register dst,
Register src,
Register length,
Register scratch,
CopyHint hint) {
UseScratchRegisterScope temps(this);
Register tmp1 = temps.AcquireX();
Register tmp2 = temps.AcquireX();
DCHECK(!AreAliased(src, dst, length, scratch, tmp1, tmp2));
DCHECK(!AreAliased(src, dst, csp));
if (emit_debug_code()) {
// Check copy length.
Cmp(length, 0);
Assert(ge, kUnexpectedNegativeValue);
// Check src and dst buffers don't overlap.
Add(scratch, src, length); // Calculate end of src buffer.
Cmp(scratch, dst);
Add(scratch, dst, length); // Calculate end of dst buffer.
Ccmp(scratch, src, ZFlag, gt);
Assert(le, kCopyBuffersOverlap);
}
Label short_copy, short_loop, bulk_loop, done;
if ((hint == kCopyLong || hint == kCopyUnknown) && !FLAG_optimize_for_size) {
Register bulk_length = scratch;
int pair_size = 2 * kXRegSize;
int pair_mask = pair_size - 1;
Bic(bulk_length, length, pair_mask);
Cbz(bulk_length, &short_copy);
Bind(&bulk_loop);
Sub(bulk_length, bulk_length, pair_size);
Ldp(tmp1, tmp2, MemOperand(src, pair_size, PostIndex));
Stp(tmp1, tmp2, MemOperand(dst, pair_size, PostIndex));
Cbnz(bulk_length, &bulk_loop);
And(length, length, pair_mask);
}
Bind(&short_copy);
Cbz(length, &done);
Bind(&short_loop);
Sub(length, length, 1);
Ldrb(tmp1, MemOperand(src, 1, PostIndex));
Strb(tmp1, MemOperand(dst, 1, PostIndex));
Cbnz(length, &short_loop);
Bind(&done);
}
void MacroAssembler::FillFields(Register dst,
Register field_count,
Register filler) {
DCHECK(!dst.Is(csp));
UseScratchRegisterScope temps(this);
Register field_ptr = temps.AcquireX();
Register counter = temps.AcquireX();
Label done;
// Decrement count. If the result < zero, count was zero, and there's nothing
// to do. If count was one, flags are set to fail the gt condition at the end
// of the pairs loop.
Subs(counter, field_count, 1);
B(lt, &done);
// There's at least one field to fill, so do this unconditionally.
Str(filler, MemOperand(dst, kPointerSize, PostIndex));
// If the bottom bit of counter is set, there are an even number of fields to
// fill, so pull the start pointer back by one field, allowing the pairs loop
// to overwrite the field that was stored above.
And(field_ptr, counter, 1);
Sub(field_ptr, dst, Operand(field_ptr, LSL, kPointerSizeLog2));
// Store filler to memory in pairs.
Label entry, loop;
B(&entry);
Bind(&loop);
Stp(filler, filler, MemOperand(field_ptr, 2 * kPointerSize, PostIndex));
Subs(counter, counter, 2);
Bind(&entry);
B(gt, &loop);
Bind(&done);
}
void MacroAssembler::JumpIfEitherIsNotSequentialOneByteStrings(
Register first, Register second, Register scratch1, Register scratch2,
Label* failure, SmiCheckType smi_check) {
if (smi_check == DO_SMI_CHECK) {
JumpIfEitherSmi(first, second, failure);
} else if (emit_debug_code()) {
DCHECK(smi_check == DONT_DO_SMI_CHECK);
Label not_smi;
JumpIfEitherSmi(first, second, NULL, &not_smi);
// At least one input is a smi, but the flags indicated a smi check wasn't
// needed.
Abort(kUnexpectedSmi);
Bind(&not_smi);
}
// Test that both first and second are sequential one-byte strings.
Ldr(scratch1, FieldMemOperand(first, HeapObject::kMapOffset));
Ldr(scratch2, FieldMemOperand(second, HeapObject::kMapOffset));
Ldrb(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
Ldrb(scratch2, FieldMemOperand(scratch2, Map::kInstanceTypeOffset));
JumpIfEitherInstanceTypeIsNotSequentialOneByte(scratch1, scratch2, scratch1,
scratch2, failure);
}
void MacroAssembler::JumpIfEitherInstanceTypeIsNotSequentialOneByte(
Register first, Register second, Register scratch1, Register scratch2,
Label* failure) {
DCHECK(!AreAliased(scratch1, second));
DCHECK(!AreAliased(scratch1, scratch2));
static const int kFlatOneByteStringMask =
kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
static const int kFlatOneByteStringTag = ONE_BYTE_STRING_TYPE;
And(scratch1, first, kFlatOneByteStringMask);
And(scratch2, second, kFlatOneByteStringMask);
Cmp(scratch1, kFlatOneByteStringTag);
Ccmp(scratch2, kFlatOneByteStringTag, NoFlag, eq);
B(ne, failure);
}
void MacroAssembler::JumpIfInstanceTypeIsNotSequentialOneByte(Register type,
Register scratch,
Label* failure) {
const int kFlatOneByteStringMask =
kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
const int kFlatOneByteStringTag =
kStringTag | kOneByteStringTag | kSeqStringTag;
And(scratch, type, kFlatOneByteStringMask);
Cmp(scratch, kFlatOneByteStringTag);
B(ne, failure);
}
void MacroAssembler::JumpIfBothInstanceTypesAreNotSequentialOneByte(
Register first, Register second, Register scratch1, Register scratch2,
Label* failure) {
DCHECK(!AreAliased(first, second, scratch1, scratch2));
const int kFlatOneByteStringMask =
kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
const int kFlatOneByteStringTag =
kStringTag | kOneByteStringTag | kSeqStringTag;
And(scratch1, first, kFlatOneByteStringMask);
And(scratch2, second, kFlatOneByteStringMask);
Cmp(scratch1, kFlatOneByteStringTag);
Ccmp(scratch2, kFlatOneByteStringTag, NoFlag, eq);
B(ne, failure);
}
void MacroAssembler::JumpIfNotUniqueNameInstanceType(Register type,
Label* not_unique_name) {
STATIC_ASSERT((kInternalizedTag == 0) && (kStringTag == 0));
// if ((type is string && type is internalized) || type == SYMBOL_TYPE) {
// continue
// } else {
// goto not_unique_name
// }
Tst(type, kIsNotStringMask | kIsNotInternalizedMask);
Ccmp(type, SYMBOL_TYPE, ZFlag, ne);
B(ne, not_unique_name);
}
void MacroAssembler::InvokePrologue(const ParameterCount& expected,
const ParameterCount& actual,
Handle<Code> code_constant,
Register code_reg,
Label* done,
InvokeFlag flag,
bool* definitely_mismatches,
const CallWrapper& call_wrapper) {
bool definitely_matches = false;
*definitely_mismatches = false;
Label regular_invoke;
// Check whether the expected and actual arguments count match. If not,
// setup registers according to contract with ArgumentsAdaptorTrampoline:
// x0: actual arguments count.
// x1: function (passed through to callee).
// x2: expected arguments count.
// The code below is made a lot easier because the calling code already sets
// up actual and expected registers according to the contract if values are
// passed in registers.
DCHECK(actual.is_immediate() || actual.reg().is(x0));
DCHECK(expected.is_immediate() || expected.reg().is(x2));
DCHECK((!code_constant.is_null() && code_reg.is(no_reg)) || code_reg.is(x3));
if (expected.is_immediate()) {
DCHECK(actual.is_immediate());
if (expected.immediate() == actual.immediate()) {
definitely_matches = true;
} else {
Mov(x0, actual.immediate());
if (expected.immediate() ==
SharedFunctionInfo::kDontAdaptArgumentsSentinel) {
// Don't worry about adapting arguments for builtins that
// don't want that done. Skip adaption code by making it look
// like we have a match between expected and actual number of
// arguments.
definitely_matches = true;
} else {
*definitely_mismatches = true;
// Set up x2 for the argument adaptor.
Mov(x2, expected.immediate());
}
}
} else { // expected is a register.
Operand actual_op = actual.is_immediate() ? Operand(actual.immediate())
: Operand(actual.reg());
// If actual == expected perform a regular invocation.
Cmp(expected.reg(), actual_op);
B(eq, &regular_invoke);
// Otherwise set up x0 for the argument adaptor.
Mov(x0, actual_op);
}
// If the argument counts may mismatch, generate a call to the argument
// adaptor.
if (!definitely_matches) {
if (!code_constant.is_null()) {
Mov(x3, Operand(code_constant));
Add(x3, x3, Code::kHeaderSize - kHeapObjectTag);
}
Handle<Code> adaptor =
isolate()->builtins()->ArgumentsAdaptorTrampoline();
if (flag == CALL_FUNCTION) {
call_wrapper.BeforeCall(CallSize(adaptor));
Call(adaptor);
call_wrapper.AfterCall();
if (!*definitely_mismatches) {
// If the arg counts don't match, no extra code is emitted by
// MAsm::InvokeCode and we can just fall through.
B(done);
}
} else {
Jump(adaptor, RelocInfo::CODE_TARGET);
}
}
Bind(&regular_invoke);
}
void MacroAssembler::InvokeCode(Register code,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag,
const CallWrapper& call_wrapper) {
// You can't call a function without a valid frame.
DCHECK(flag == JUMP_FUNCTION || has_frame());
Label done;
bool definitely_mismatches = false;
InvokePrologue(expected, actual, Handle<Code>::null(), code, &done, flag,
&definitely_mismatches, call_wrapper);
// If we are certain that actual != expected, then we know InvokePrologue will
// have handled the call through the argument adaptor mechanism.
// The called function expects the call kind in x5.
if (!definitely_mismatches) {
if (flag == CALL_FUNCTION) {
call_wrapper.BeforeCall(CallSize(code));
Call(code);
call_wrapper.AfterCall();
} else {
DCHECK(flag == JUMP_FUNCTION);
Jump(code);
}
}
// Continue here if InvokePrologue does handle the invocation due to
// mismatched parameter counts.
Bind(&done);
}
void MacroAssembler::InvokeFunction(Register function,
const ParameterCount& actual,
InvokeFlag flag,
const CallWrapper& call_wrapper) {
// You can't call a function without a valid frame.
DCHECK(flag == JUMP_FUNCTION || has_frame());
// Contract with called JS functions requires that function is passed in x1.
// (See FullCodeGenerator::Generate().)
DCHECK(function.is(x1));
Register expected_reg = x2;
Register code_reg = x3;
Ldr(cp, FieldMemOperand(function, JSFunction::kContextOffset));
// The number of arguments is stored as an int32_t, and -1 is a marker
// (SharedFunctionInfo::kDontAdaptArgumentsSentinel), so we need sign
// extension to correctly handle it.
Ldr(expected_reg, FieldMemOperand(function,
JSFunction::kSharedFunctionInfoOffset));
Ldrsw(expected_reg,
FieldMemOperand(expected_reg,
SharedFunctionInfo::kFormalParameterCountOffset));
Ldr(code_reg,
FieldMemOperand(function, JSFunction::kCodeEntryOffset));
ParameterCount expected(expected_reg);
InvokeCode(code_reg, expected, actual, flag, call_wrapper);
}
void MacroAssembler::InvokeFunction(Register function,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag,
const CallWrapper& call_wrapper) {
// You can't call a function without a valid frame.
DCHECK(flag == JUMP_FUNCTION || has_frame());
// Contract with called JS functions requires that function is passed in x1.
// (See FullCodeGenerator::Generate().)
DCHECK(function.Is(x1));
Register code_reg = x3;
// Set up the context.
Ldr(cp, FieldMemOperand(function, JSFunction::kContextOffset));
// We call indirectly through the code field in the function to
// allow recompilation to take effect without changing any of the
// call sites.
Ldr(code_reg, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
InvokeCode(code_reg, expected, actual, flag, call_wrapper);
}
void MacroAssembler::InvokeFunction(Handle<JSFunction> function,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag,
const CallWrapper& call_wrapper) {
// Contract with called JS functions requires that function is passed in x1.
// (See FullCodeGenerator::Generate().)
__ LoadObject(x1, function);
InvokeFunction(x1, expected, actual, flag, call_wrapper);
}
void MacroAssembler::TryConvertDoubleToInt64(Register result,
DoubleRegister double_input,
Label* done) {
// Try to convert with an FPU convert instruction. It's trivial to compute
// the modulo operation on an integer register so we convert to a 64-bit
// integer.
//
// Fcvtzs will saturate to INT64_MIN (0x800...00) or INT64_MAX (0x7ff...ff)
// when the double is out of range. NaNs and infinities will be converted to 0
// (as ECMA-262 requires).
Fcvtzs(result.X(), double_input);
// The values INT64_MIN (0x800...00) or INT64_MAX (0x7ff...ff) are not
// representable using a double, so if the result is one of those then we know
// that saturation occured, and we need to manually handle the conversion.
//
// It is easy to detect INT64_MIN and INT64_MAX because adding or subtracting
// 1 will cause signed overflow.
Cmp(result.X(), 1);
Ccmp(result.X(), -1, VFlag, vc);
B(vc, done);
}
void MacroAssembler::TruncateDoubleToI(Register result,
DoubleRegister double_input) {
Label done;
// Try to convert the double to an int64. If successful, the bottom 32 bits
// contain our truncated int32 result.
TryConvertDoubleToInt64(result, double_input, &done);
const Register old_stack_pointer = StackPointer();
if (csp.Is(old_stack_pointer)) {
// This currently only happens during compiler-unittest. If it arises
// during regular code generation the DoubleToI stub should be updated to
// cope with csp and have an extra parameter indicating which stack pointer
// it should use.
Push(jssp, xzr); // Push xzr to maintain csp required 16-bytes alignment.
Mov(jssp, csp);
SetStackPointer(jssp);
}
// If we fell through then inline version didn't succeed - call stub instead.
Push(lr, double_input);
DoubleToIStub stub(isolate(),
jssp,
result,
0,
true, // is_truncating
true); // skip_fastpath
CallStub(&stub); // DoubleToIStub preserves any registers it needs to clobber
DCHECK_EQ(xzr.SizeInBytes(), double_input.SizeInBytes());
Pop(xzr, lr); // xzr to drop the double input on the stack.
if (csp.Is(old_stack_pointer)) {
Mov(csp, jssp);
SetStackPointer(csp);
AssertStackConsistency();
Pop(xzr, jssp);
}
Bind(&done);
}
void MacroAssembler::TruncateHeapNumberToI(Register result,
Register object) {
Label done;
DCHECK(!result.is(object));
DCHECK(jssp.Is(StackPointer()));
Ldr(fp_scratch, FieldMemOperand(object, HeapNumber::kValueOffset));
// Try to convert the double to an int64. If successful, the bottom 32 bits
// contain our truncated int32 result.
TryConvertDoubleToInt64(result, fp_scratch, &done);
// If we fell through then inline version didn't succeed - call stub instead.
Push(lr);
DoubleToIStub stub(isolate(),
object,
result,
HeapNumber::kValueOffset - kHeapObjectTag,
true, // is_truncating
true); // skip_fastpath
CallStub(&stub); // DoubleToIStub preserves any registers it needs to clobber
Pop(lr);
Bind(&done);
}
void MacroAssembler::StubPrologue() {
DCHECK(StackPointer().Is(jssp));
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
__ Mov(temp, Smi::FromInt(StackFrame::STUB));
// Compiled stubs don't age, and so they don't need the predictable code
// ageing sequence.
__ Push(lr, fp, cp, temp);
__ Add(fp, jssp, StandardFrameConstants::kFixedFrameSizeFromFp);
}
void MacroAssembler::Prologue(bool code_pre_aging) {
if (code_pre_aging) {
Code* stub = Code::GetPreAgedCodeAgeStub(isolate());
__ EmitCodeAgeSequence(stub);
} else {
__ EmitFrameSetupForCodeAgePatching();
}
}
void MacroAssembler::EnterFrame(StackFrame::Type type,
bool load_constant_pool_pointer_reg) {
// Out-of-line constant pool not implemented on arm64.
UNREACHABLE();
}
void MacroAssembler::EnterFrame(StackFrame::Type type) {
DCHECK(jssp.Is(StackPointer()));
UseScratchRegisterScope temps(this);
Register type_reg = temps.AcquireX();
Register code_reg = temps.AcquireX();
Push(lr, fp, cp);
Mov(type_reg, Smi::FromInt(type));
Mov(code_reg, Operand(CodeObject()));
Push(type_reg, code_reg);
// jssp[4] : lr
// jssp[3] : fp
// jssp[2] : cp
// jssp[1] : type
// jssp[0] : code object
// Adjust FP to point to saved FP.
Add(fp, jssp, StandardFrameConstants::kFixedFrameSizeFromFp + kPointerSize);
}
void MacroAssembler::LeaveFrame(StackFrame::Type type) {
DCHECK(jssp.Is(StackPointer()));
// Drop the execution stack down to the frame pointer and restore
// the caller frame pointer and return address.
Mov(jssp, fp);
AssertStackConsistency();
Pop(fp, lr);
}
void MacroAssembler::ExitFramePreserveFPRegs() {
PushCPURegList(kCallerSavedFP);
}
void MacroAssembler::ExitFrameRestoreFPRegs() {
// Read the registers from the stack without popping them. The stack pointer
// will be reset as part of the unwinding process.
CPURegList saved_fp_regs = kCallerSavedFP;
DCHECK(saved_fp_regs.Count() % 2 == 0);
int offset = ExitFrameConstants::kLastExitFrameField;
while (!saved_fp_regs.IsEmpty()) {
const CPURegister& dst0 = saved_fp_regs.PopHighestIndex();
const CPURegister& dst1 = saved_fp_regs.PopHighestIndex();
offset -= 2 * kDRegSize;
Ldp(dst1, dst0, MemOperand(fp, offset));
}
}
void MacroAssembler::EnterExitFrame(bool save_doubles,
const Register& scratch,
int extra_space) {
DCHECK(jssp.Is(StackPointer()));
// Set up the new stack frame.
Mov(scratch, Operand(CodeObject()));
Push(lr, fp);
Mov(fp, StackPointer());
Push(xzr, scratch);
// fp[8]: CallerPC (lr)
// fp -> fp[0]: CallerFP (old fp)
// fp[-8]: Space reserved for SPOffset.
// jssp -> fp[-16]: CodeObject()
STATIC_ASSERT((2 * kPointerSize) ==
ExitFrameConstants::kCallerSPDisplacement);
STATIC_ASSERT((1 * kPointerSize) == ExitFrameConstants::kCallerPCOffset);
STATIC_ASSERT((0 * kPointerSize) == ExitFrameConstants::kCallerFPOffset);
STATIC_ASSERT((-1 * kPointerSize) == ExitFrameConstants::kSPOffset);
STATIC_ASSERT((-2 * kPointerSize) == ExitFrameConstants::kCodeOffset);
// Save the frame pointer and context pointer in the top frame.
Mov(scratch, Operand(ExternalReference(Isolate::kCEntryFPAddress,
isolate())));
Str(fp, MemOperand(scratch));
Mov(scratch, Operand(ExternalReference(Isolate::kContextAddress,
isolate())));
Str(cp, MemOperand(scratch));
STATIC_ASSERT((-2 * kPointerSize) ==
ExitFrameConstants::kLastExitFrameField);
if (save_doubles) {
ExitFramePreserveFPRegs();
}
// Reserve space for the return address and for user requested memory.
// We do this before aligning to make sure that we end up correctly
// aligned with the minimum of wasted space.
Claim(extra_space + 1, kXRegSize);
// fp[8]: CallerPC (lr)
// fp -> fp[0]: CallerFP (old fp)
// fp[-8]: Space reserved for SPOffset.
// fp[-16]: CodeObject()
// fp[-16 - fp_size]: Saved doubles (if save_doubles is true).
// jssp[8]: Extra space reserved for caller (if extra_space != 0).
// jssp -> jssp[0]: Space reserved for the return address.
// Align and synchronize the system stack pointer with jssp.
AlignAndSetCSPForFrame();
DCHECK(csp.Is(StackPointer()));
// fp[8]: CallerPC (lr)
// fp -> fp[0]: CallerFP (old fp)
// fp[-8]: Space reserved for SPOffset.
// fp[-16]: CodeObject()
// fp[-16 - fp_size]: Saved doubles (if save_doubles is true).
// csp[8]: Memory reserved for the caller if extra_space != 0.
// Alignment padding, if necessary.
// csp -> csp[0]: Space reserved for the return address.
// ExitFrame::GetStateForFramePointer expects to find the return address at
// the memory address immediately below the pointer stored in SPOffset.
// It is not safe to derive much else from SPOffset, because the size of the
// padding can vary.
Add(scratch, csp, kXRegSize);
Str(scratch, MemOperand(fp, ExitFrameConstants::kSPOffset));
}
// Leave the current exit frame.
void MacroAssembler::LeaveExitFrame(bool restore_doubles,
const Register& scratch,
bool restore_context) {
DCHECK(csp.Is(StackPointer()));
if (restore_doubles) {
ExitFrameRestoreFPRegs();
}
// Restore the context pointer from the top frame.
if (restore_context) {
Mov(scratch, Operand(ExternalReference(Isolate::kContextAddress,
isolate())));
Ldr(cp, MemOperand(scratch));
}
if (emit_debug_code()) {
// Also emit debug code to clear the cp in the top frame.
Mov(scratch, Operand(ExternalReference(Isolate::kContextAddress,
isolate())));
Str(xzr, MemOperand(scratch));
}
// Clear the frame pointer from the top frame.
Mov(scratch, Operand(ExternalReference(Isolate::kCEntryFPAddress,
isolate())));
Str(xzr, MemOperand(scratch));
// Pop the exit frame.
// fp[8]: CallerPC (lr)
// fp -> fp[0]: CallerFP (old fp)
// fp[...]: The rest of the frame.
Mov(jssp, fp);
SetStackPointer(jssp);
AssertStackConsistency();
Pop(fp, lr);
}
void MacroAssembler::SetCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
if (FLAG_native_code_counters && counter->Enabled()) {
Mov(scratch1, value);
Mov(scratch2, ExternalReference(counter));
Str(scratch1, MemOperand(scratch2));
}
}
void MacroAssembler::IncrementCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
DCHECK(value != 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Mov(scratch2, ExternalReference(counter));
Ldr(scratch1, MemOperand(scratch2));
Add(scratch1, scratch1, value);
Str(scratch1, MemOperand(scratch2));
}
}
void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
IncrementCounter(counter, -value, scratch1, scratch2);
}
void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
if (context_chain_length > 0) {
// Move up the chain of contexts to the context containing the slot.
Ldr(dst, MemOperand(cp, Context::SlotOffset(Context::PREVIOUS_INDEX)));
for (int i = 1; i < context_chain_length; i++) {
Ldr(dst, MemOperand(dst, Context::SlotOffset(Context::PREVIOUS_INDEX)));
}
} else {
// Slot is in the current function context. Move it into the
// destination register in case we store into it (the write barrier
// cannot be allowed to destroy the context in cp).
Mov(dst, cp);
}
}
void MacroAssembler::DebugBreak() {
Mov(x0, 0);
Mov(x1, ExternalReference(Runtime::kDebugBreak, isolate()));
CEntryStub ces(isolate(), 1);
DCHECK(AllowThisStubCall(&ces));
Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
}
void MacroAssembler::PushTryHandler(StackHandler::Kind kind,
int handler_index) {
DCHECK(jssp.Is(StackPointer()));
// Adjust this code if the asserts don't hold.
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
// For the JSEntry handler, we must preserve the live registers x0-x4.
// (See JSEntryStub::GenerateBody().)
unsigned state =
StackHandler::IndexField::encode(handler_index) |
StackHandler::KindField::encode(kind);
// Set up the code object and the state for pushing.
Mov(x10, Operand(CodeObject()));
Mov(x11, state);
// Push the frame pointer, context, state, and code object.
if (kind == StackHandler::JS_ENTRY) {
DCHECK(Smi::FromInt(0) == 0);
Push(xzr, xzr, x11, x10);
} else {
Push(fp, cp, x11, x10);
}
// Link the current handler as the next handler.
Mov(x11, ExternalReference(Isolate::kHandlerAddress, isolate()));
Ldr(x10, MemOperand(x11));
Push(x10);
// Set this new handler as the current one.
Str(jssp, MemOperand(x11));
}
void MacroAssembler::PopTryHandler() {
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
Pop(x10);
Mov(x11, ExternalReference(Isolate::kHandlerAddress, isolate()));
Drop(StackHandlerConstants::kSize - kXRegSize, kByteSizeInBytes);
Str(x10, MemOperand(x11));
}
void MacroAssembler::Allocate(int object_size,
Register result,
Register scratch1,
Register scratch2,
Label* gc_required,
AllocationFlags flags) {
DCHECK(object_size <= Page::kMaxRegularHeapObjectSize);
if (!FLAG_inline_new) {
if (emit_debug_code()) {
// Trash the registers to simulate an allocation failure.
// We apply salt to the original zap value to easily spot the values.
Mov(result, (kDebugZapValue & ~0xffL) | 0x11L);
Mov(scratch1, (kDebugZapValue & ~0xffL) | 0x21L);
Mov(scratch2, (kDebugZapValue & ~0xffL) | 0x21L);
}
B(gc_required);
return;
}
UseScratchRegisterScope temps(this);
Register scratch3 = temps.AcquireX();
DCHECK(!AreAliased(result, scratch1, scratch2, scratch3));
DCHECK(result.Is64Bits() && scratch1.Is64Bits() && scratch2.Is64Bits());
// Make object size into bytes.
if ((flags & SIZE_IN_WORDS) != 0) {
object_size *= kPointerSize;
}
DCHECK(0 == (object_size & kObjectAlignmentMask));
// Check relative positions of allocation top and limit addresses.
// The values must be adjacent in memory to allow the use of LDP.
ExternalReference heap_allocation_top =
AllocationUtils::GetAllocationTopReference(isolate(), flags);
ExternalReference heap_allocation_limit =
AllocationUtils::GetAllocationLimitReference(isolate(), flags);
intptr_t top = reinterpret_cast<intptr_t>(heap_allocation_top.address());
intptr_t limit = reinterpret_cast<intptr_t>(heap_allocation_limit.address());
DCHECK((limit - top) == kPointerSize);
// Set up allocation top address and object size registers.
Register top_address = scratch1;
Register allocation_limit = scratch2;
Mov(top_address, Operand(heap_allocation_top));
if ((flags & RESULT_CONTAINS_TOP) == 0) {
// Load allocation top into result and the allocation limit.
Ldp(result, allocation_limit, MemOperand(top_address));
} else {
if (emit_debug_code()) {
// Assert that result actually contains top on entry.
Ldr(scratch3, MemOperand(top_address));
Cmp(result, scratch3);
Check(eq, kUnexpectedAllocationTop);
}
// Load the allocation limit. 'result' already contains the allocation top.
Ldr(allocation_limit, MemOperand(top_address, limit - top));
}
// We can ignore DOUBLE_ALIGNMENT flags here because doubles and pointers have
// the same alignment on ARM64.
STATIC_ASSERT(kPointerAlignment == kDoubleAlignment);
// Calculate new top and bail out if new space is exhausted.
Adds(scratch3, result, object_size);
Ccmp(scratch3, allocation_limit, CFlag, cc);
B(hi, gc_required);
Str(scratch3, MemOperand(top_address));
// Tag the object if requested.
if ((flags & TAG_OBJECT) != 0) {
ObjectTag(result, result);
}
}
void MacroAssembler::Allocate(Register object_size,
Register result,
Register scratch1,
Register scratch2,
Label* gc_required,
AllocationFlags flags) {
if (!FLAG_inline_new) {
if (emit_debug_code()) {
// Trash the registers to simulate an allocation failure.
// We apply salt to the original zap value to easily spot the values.
Mov(result, (kDebugZapValue & ~0xffL) | 0x11L);
Mov(scratch1, (kDebugZapValue & ~0xffL) | 0x21L);
Mov(scratch2, (kDebugZapValue & ~0xffL) | 0x21L);
}
B(gc_required);
return;
}
UseScratchRegisterScope temps(this);
Register scratch3 = temps.AcquireX();
DCHECK(!AreAliased(object_size, result, scratch1, scratch2, scratch3));
DCHECK(object_size.Is64Bits() && result.Is64Bits() &&
scratch1.Is64Bits() && scratch2.Is64Bits());
// Check relative positions of allocation top and limit addresses.
// The values must be adjacent in memory to allow the use of LDP.
ExternalReference heap_allocation_top =
AllocationUtils::GetAllocationTopReference(isolate(), flags);
ExternalReference heap_allocation_limit =
AllocationUtils::GetAllocationLimitReference(isolate(), flags);
intptr_t top = reinterpret_cast<intptr_t>(heap_allocation_top.address());
intptr_t limit = reinterpret_cast<intptr_t>(heap_allocation_limit.address());
DCHECK((limit - top) == kPointerSize);
// Set up allocation top address and object size registers.
Register top_address = scratch1;
Register allocation_limit = scratch2;
Mov(top_address, heap_allocation_top);
if ((flags & RESULT_CONTAINS_TOP) == 0) {
// Load allocation top into result and the allocation limit.
Ldp(result, allocation_limit, MemOperand(top_address));
} else {
if (emit_debug_code()) {
// Assert that result actually contains top on entry.
Ldr(scratch3, MemOperand(top_address));
Cmp(result, scratch3);
Check(eq, kUnexpectedAllocationTop);
}
// Load the allocation limit. 'result' already contains the allocation top.
Ldr(allocation_limit, MemOperand(top_address, limit - top));
}
// We can ignore DOUBLE_ALIGNMENT flags here because doubles and pointers have
// the same alignment on ARM64.
STATIC_ASSERT(kPointerAlignment == kDoubleAlignment);
// Calculate new top and bail out if new space is exhausted
if ((flags & SIZE_IN_WORDS) != 0) {
Adds(scratch3, result, Operand(object_size, LSL, kPointerSizeLog2));
} else {
Adds(scratch3, result, object_size);
}
if (emit_debug_code()) {
Tst(scratch3, kObjectAlignmentMask);
Check(eq, kUnalignedAllocationInNewSpace);
}
Ccmp(scratch3, allocation_limit, CFlag, cc);
B(hi, gc_required);
Str(scratch3, MemOperand(top_address));
// Tag the object if requested.
if ((flags & TAG_OBJECT) != 0) {
ObjectTag(result, result);
}
}
void MacroAssembler::UndoAllocationInNewSpace(Register object,
Register scratch) {
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address(isolate());
// Make sure the object has no tag before resetting top.
Bic(object, object, kHeapObjectTagMask);
#ifdef DEBUG
// Check that the object un-allocated is below the current top.
Mov(scratch, new_space_allocation_top);
Ldr(scratch, MemOperand(scratch));
Cmp(object, scratch);
Check(lt, kUndoAllocationOfNonAllocatedMemory);
#endif
// Write the address of the object to un-allocate as the current top.
Mov(scratch, new_space_allocation_top);
Str(object, MemOperand(scratch));
}
void MacroAssembler::AllocateTwoByteString(Register result,
Register length,
Register scratch1,
Register scratch2,
Register scratch3,
Label* gc_required) {
DCHECK(!AreAliased(result, length, scratch1, scratch2, scratch3));
// Calculate the number of bytes needed for the characters in the string while
// observing object alignment.
STATIC_ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
Add(scratch1, length, length); // Length in bytes, not chars.
Add(scratch1, scratch1, kObjectAlignmentMask + SeqTwoByteString::kHeaderSize);
Bic(scratch1, scratch1, kObjectAlignmentMask);
// Allocate two-byte string in new space.
Allocate(scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
InitializeNewString(result,
length,
Heap::kStringMapRootIndex,
scratch1,
scratch2);
}
void MacroAssembler::AllocateOneByteString(Register result, Register length,
Register scratch1, Register scratch2,
Register scratch3,
Label* gc_required) {
DCHECK(!AreAliased(result, length, scratch1, scratch2, scratch3));
// Calculate the number of bytes needed for the characters in the string while
// observing object alignment.
STATIC_ASSERT((SeqOneByteString::kHeaderSize & kObjectAlignmentMask) == 0);
STATIC_ASSERT(kCharSize == 1);
Add(scratch1, length, kObjectAlignmentMask + SeqOneByteString::kHeaderSize);
Bic(scratch1, scratch1, kObjectAlignmentMask);
// Allocate one-byte string in new space.
Allocate(scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
InitializeNewString(result, length, Heap::kOneByteStringMapRootIndex,
scratch1, scratch2);
}
void MacroAssembler::AllocateTwoByteConsString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
Allocate(ConsString::kSize, result, scratch1, scratch2, gc_required,
TAG_OBJECT);
InitializeNewString(result,
length,
Heap::kConsStringMapRootIndex,
scratch1,
scratch2);
}
void MacroAssembler::AllocateOneByteConsString(Register result, Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
Allocate(ConsString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
InitializeNewString(result, length, Heap::kConsOneByteStringMapRootIndex,
scratch1, scratch2);
}
void MacroAssembler::AllocateTwoByteSlicedString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
DCHECK(!AreAliased(result, length, scratch1, scratch2));
Allocate(SlicedString::kSize, result, scratch1, scratch2, gc_required,
TAG_OBJECT);
InitializeNewString(result,
length,
Heap::kSlicedStringMapRootIndex,
scratch1,
scratch2);
}
void MacroAssembler::AllocateOneByteSlicedString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
DCHECK(!AreAliased(result, length, scratch1, scratch2));
Allocate(SlicedString::kSize, result, scratch1, scratch2, gc_required,
TAG_OBJECT);
InitializeNewString(result, length, Heap::kSlicedOneByteStringMapRootIndex,
scratch1, scratch2);
}
// Allocates a heap number or jumps to the need_gc label if the young space
// is full and a scavenge is needed.
void MacroAssembler::AllocateHeapNumber(Register result,
Label* gc_required,
Register scratch1,
Register scratch2,
CPURegister value,
CPURegister heap_number_map,
MutableMode mode) {
DCHECK(!value.IsValid() || value.Is64Bits());
UseScratchRegisterScope temps(this);
// Allocate an object in the heap for the heap number and tag it as a heap
// object.
Allocate(HeapNumber::kSize, result, scratch1, scratch2, gc_required,
NO_ALLOCATION_FLAGS);
Heap::RootListIndex map_index = mode == MUTABLE
? Heap::kMutableHeapNumberMapRootIndex
: Heap::kHeapNumberMapRootIndex;
// Prepare the heap number map.
if (!heap_number_map.IsValid()) {
// If we have a valid value register, use the same type of register to store
// the map so we can use STP to store both in one instruction.
if (value.IsValid() && value.IsFPRegister()) {
heap_number_map = temps.AcquireD();
} else {
heap_number_map = scratch1;
}
LoadRoot(heap_number_map, map_index);
}
if (emit_debug_code()) {
Register map;
if (heap_number_map.IsFPRegister()) {
map = scratch1;
Fmov(map, DoubleRegister(heap_number_map));
} else {
map = Register(heap_number_map);
}
AssertRegisterIsRoot(map, map_index);
}
// Store the heap number map and the value in the allocated object.
if (value.IsSameSizeAndType(heap_number_map)) {
STATIC_ASSERT(HeapObject::kMapOffset + kPointerSize ==
HeapNumber::kValueOffset);
Stp(heap_number_map, value, MemOperand(result, HeapObject::kMapOffset));
} else {
Str(heap_number_map, MemOperand(result, HeapObject::kMapOffset));
if (value.IsValid()) {
Str(value, MemOperand(result, HeapNumber::kValueOffset));
}
}
ObjectTag(result, result);
}
void MacroAssembler::JumpIfObjectType(Register object,
Register map,
Register type_reg,
InstanceType type,
Label* if_cond_pass,
Condition cond) {
CompareObjectType(object, map, type_reg, type);
B(cond, if_cond_pass);
}
void MacroAssembler::JumpIfNotObjectType(Register object,
Register map,
Register type_reg,
InstanceType type,
Label* if_not_object) {
JumpIfObjectType(object, map, type_reg, type, if_not_object, ne);
}
// Sets condition flags based on comparison, and returns type in type_reg.
void MacroAssembler::CompareObjectType(Register object,
Register map,
Register type_reg,
InstanceType type) {
Ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
CompareInstanceType(map, type_reg, type);
}
// Sets condition flags based on comparison, and returns type in type_reg.
void MacroAssembler::CompareInstanceType(Register map,
Register type_reg,
InstanceType type) {
Ldrb(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
Cmp(type_reg, type);
}
void MacroAssembler::CompareObjectMap(Register obj, Heap::RootListIndex index) {
UseScratchRegisterScope temps(this);
Register obj_map = temps.AcquireX();
Ldr(obj_map, FieldMemOperand(obj, HeapObject::kMapOffset));
CompareRoot(obj_map, index);
}
void MacroAssembler::CompareObjectMap(Register obj, Register scratch,
Handle<Map> map) {
Ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
CompareMap(scratch, map);
}
void MacroAssembler::CompareMap(Register obj_map,
Handle<Map> map) {
Cmp(obj_map, Operand(map));
}
void MacroAssembler::CheckMap(Register obj,
Register scratch,
Handle<Map> map,
Label* fail,
SmiCheckType smi_check_type) {
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(obj, fail);
}
CompareObjectMap(obj, scratch, map);
B(ne, fail);
}
void MacroAssembler::CheckMap(Register obj,
Register scratch,
Heap::RootListIndex index,
Label* fail,
SmiCheckType smi_check_type) {
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(obj, fail);
}
Ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
JumpIfNotRoot(scratch, index, fail);
}
void MacroAssembler::CheckMap(Register obj_map,
Handle<Map> map,
Label* fail,
SmiCheckType smi_check_type) {
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(obj_map, fail);
}
CompareMap(obj_map, map);
B(ne, fail);
}
void MacroAssembler::DispatchWeakMap(Register obj, Register scratch1,
Register scratch2, Handle<WeakCell> cell,
Handle<Code> success,
SmiCheckType smi_check_type) {
Label fail;
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(obj, &fail);
}
Ldr(scratch1, FieldMemOperand(obj, HeapObject::kMapOffset));
CmpWeakValue(scratch1, cell, scratch2);
B(ne, &fail);
Jump(success, RelocInfo::CODE_TARGET);
Bind(&fail);
}
void MacroAssembler::CmpWeakValue(Register value, Handle<WeakCell> cell,
Register scratch) {
Mov(scratch, Operand(cell));
Ldr(scratch, FieldMemOperand(scratch, WeakCell::kValueOffset));
Cmp(value, scratch);
}
void MacroAssembler::LoadWeakValue(Register value, Handle<WeakCell> cell,
Label* miss) {
Mov(value, Operand(cell));
Ldr(value, FieldMemOperand(value, WeakCell::kValueOffset));
JumpIfSmi(value, miss);
}
void MacroAssembler::TestMapBitfield(Register object, uint64_t mask) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
Ldrb(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
Tst(temp, mask);
}
void MacroAssembler::LoadElementsKindFromMap(Register result, Register map) {
// Load the map's "bit field 2".
__ Ldrb(result, FieldMemOperand(map, Map::kBitField2Offset));
// Retrieve elements_kind from bit field 2.
DecodeField<Map::ElementsKindBits>(result);
}
void MacroAssembler::TryGetFunctionPrototype(Register function,
Register result,
Register scratch,
Label* miss,
BoundFunctionAction action) {
DCHECK(!AreAliased(function, result, scratch));
Label non_instance;
if (action == kMissOnBoundFunction) {
// Check that the receiver isn't a smi.
JumpIfSmi(function, miss);
// Check that the function really is a function. Load map into result reg.
JumpIfNotObjectType(function, result, scratch, JS_FUNCTION_TYPE, miss);
Register scratch_w = scratch.W();
Ldr(scratch,
FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
// On 64-bit platforms, compiler hints field is not a smi. See definition of
// kCompilerHintsOffset in src/objects.h.
Ldr(scratch_w,
FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));
Tbnz(scratch, SharedFunctionInfo::kBoundFunction, miss);
// Make sure that the function has an instance prototype.
Ldrb(scratch, FieldMemOperand(result, Map::kBitFieldOffset));
Tbnz(scratch, Map::kHasNonInstancePrototype, &non_instance);
}
// Get the prototype or initial map from the function.
Ldr(result,
FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
// If the prototype or initial map is the hole, don't return it and simply
// miss the cache instead. This will allow us to allocate a prototype object
// on-demand in the runtime system.
JumpIfRoot(result, Heap::kTheHoleValueRootIndex, miss);
// If the function does not have an initial map, we're done.
Label done;
JumpIfNotObjectType(result, scratch, scratch, MAP_TYPE, &done);
// Get the prototype from the initial map.
Ldr(result, FieldMemOperand(result, Map::kPrototypeOffset));
if (action == kMissOnBoundFunction) {
B(&done);
// Non-instance prototype: fetch prototype from constructor field in initial
// map.
Bind(&non_instance);
Ldr(result, FieldMemOperand(result, Map::kConstructorOffset));
}
// All done.
Bind(&done);
}
void MacroAssembler::CompareRoot(const Register& obj,
Heap::RootListIndex index) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
DCHECK(!AreAliased(obj, temp));
LoadRoot(temp, index);
Cmp(obj, temp);
}
void MacroAssembler::JumpIfRoot(const Register& obj,
Heap::RootListIndex index,
Label* if_equal) {
CompareRoot(obj, index);
B(eq, if_equal);
}
void MacroAssembler::JumpIfNotRoot(const Register& obj,
Heap::RootListIndex index,
Label* if_not_equal) {
CompareRoot(obj, index);
B(ne, if_not_equal);
}
void MacroAssembler::CompareAndSplit(const Register& lhs,
const Operand& rhs,
Condition cond,
Label* if_true,
Label* if_false,
Label* fall_through) {
if ((if_true == if_false) && (if_false == fall_through)) {
// Fall through.
} else if (if_true == if_false) {
B(if_true);
} else if (if_false == fall_through) {
CompareAndBranch(lhs, rhs, cond, if_true);
} else if (if_true == fall_through) {
CompareAndBranch(lhs, rhs, NegateCondition(cond), if_false);
} else {
CompareAndBranch(lhs, rhs, cond, if_true);
B(if_false);
}
}
void MacroAssembler::TestAndSplit(const Register& reg,
uint64_t bit_pattern,
Label* if_all_clear,
Label* if_any_set,
Label* fall_through) {
if ((if_all_clear == if_any_set) && (if_any_set == fall_through)) {
// Fall through.
} else if (if_all_clear == if_any_set) {
B(if_all_clear);
} else if (if_all_clear == fall_through) {
TestAndBranchIfAnySet(reg, bit_pattern, if_any_set);
} else if (if_any_set == fall_through) {
TestAndBranchIfAllClear(reg, bit_pattern, if_all_clear);
} else {
TestAndBranchIfAnySet(reg, bit_pattern, if_any_set);
B(if_all_clear);
}
}
void MacroAssembler::CheckFastElements(Register map,
Register scratch,
Label* fail) {
STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
STATIC_ASSERT(FAST_ELEMENTS == 2);
STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
Ldrb(scratch, FieldMemOperand(map, Map::kBitField2Offset));
Cmp(scratch, Map::kMaximumBitField2FastHoleyElementValue);
B(hi, fail);
}
void MacroAssembler::CheckFastObjectElements(Register map,
Register scratch,
Label* fail) {
STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
STATIC_ASSERT(FAST_ELEMENTS == 2);
STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
Ldrb(scratch, FieldMemOperand(map, Map::kBitField2Offset));
Cmp(scratch, Operand(Map::kMaximumBitField2FastHoleySmiElementValue));
// If cond==ls, set cond=hi, otherwise compare.
Ccmp(scratch,
Operand(Map::kMaximumBitField2FastHoleyElementValue), CFlag, hi);
B(hi, fail);
}
// Note: The ARM version of this clobbers elements_reg, but this version does
// not. Some uses of this in ARM64 assume that elements_reg will be preserved.
void MacroAssembler::StoreNumberToDoubleElements(Register value_reg,
Register key_reg,
Register elements_reg,
Register scratch1,
FPRegister fpscratch1,
Label* fail,
int elements_offset) {
DCHECK(!AreAliased(value_reg, key_reg, elements_reg, scratch1));
Label store_num;
// Speculatively convert the smi to a double - all smis can be exactly
// represented as a double.
SmiUntagToDouble(fpscratch1, value_reg, kSpeculativeUntag);
// If value_reg is a smi, we're done.
JumpIfSmi(value_reg, &store_num);
// Ensure that the object is a heap number.
JumpIfNotHeapNumber(value_reg, fail);
Ldr(fpscratch1, FieldMemOperand(value_reg, HeapNumber::kValueOffset));
// Canonicalize NaNs.
CanonicalizeNaN(fpscratch1);
// Store the result.
Bind(&store_num);
Add(scratch1, elements_reg,
Operand::UntagSmiAndScale(key_reg, kDoubleSizeLog2));
Str(fpscratch1,
FieldMemOperand(scratch1,
FixedDoubleArray::kHeaderSize - elements_offset));
}
bool MacroAssembler::AllowThisStubCall(CodeStub* stub) {
return has_frame_ || !stub->SometimesSetsUpAFrame();
}
void MacroAssembler::IndexFromHash(Register hash, Register index) {
// If the hash field contains an array index pick it out. The assert checks
// that the constants for the maximum number of digits for an array index
// cached in the hash field and the number of bits reserved for it does not
// conflict.
DCHECK(TenToThe(String::kMaxCachedArrayIndexLength) <
(1 << String::kArrayIndexValueBits));
DecodeField<String::ArrayIndexValueBits>(index, hash);
SmiTag(index, index);
}
void MacroAssembler::EmitSeqStringSetCharCheck(
Register string,
Register index,
SeqStringSetCharCheckIndexType index_type,
Register scratch,
uint32_t encoding_mask) {
DCHECK(!AreAliased(string, index, scratch));
if (index_type == kIndexIsSmi) {
AssertSmi(index);
}
// Check that string is an object.
AssertNotSmi(string, kNonObject);
// Check that string has an appropriate map.
Ldr(scratch, FieldMemOperand(string, HeapObject::kMapOffset));
Ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
And(scratch, scratch, kStringRepresentationMask | kStringEncodingMask);
Cmp(scratch, encoding_mask);
Check(eq, kUnexpectedStringType);
Ldr(scratch, FieldMemOperand(string, String::kLengthOffset));
Cmp(index, index_type == kIndexIsSmi ? scratch : Operand::UntagSmi(scratch));
Check(lt, kIndexIsTooLarge);
DCHECK_EQ(0, Smi::FromInt(0));
Cmp(index, 0);
Check(ge, kIndexIsNegative);
}
void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
Register scratch1,
Register scratch2,
Label* miss) {
DCHECK(!AreAliased(holder_reg, scratch1, scratch2));
Label same_contexts;
// Load current lexical context from the stack frame.
Ldr(scratch1, MemOperand(fp, StandardFrameConstants::kContextOffset));
// In debug mode, make sure the lexical context is set.
#ifdef DEBUG
Cmp(scratch1, 0);
Check(ne, kWeShouldNotHaveAnEmptyLexicalContext);
#endif
// Load the native context of the current context.
int offset =
Context::kHeaderSize + Context::GLOBAL_OBJECT_INDEX * kPointerSize;
Ldr(scratch1, FieldMemOperand(scratch1, offset));
Ldr(scratch1, FieldMemOperand(scratch1, GlobalObject::kNativeContextOffset));
// Check the context is a native context.
if (emit_debug_code()) {
// Read the first word and compare to the native_context_map.
Ldr(scratch2, FieldMemOperand(scratch1, HeapObject::kMapOffset));
CompareRoot(scratch2, Heap::kNativeContextMapRootIndex);
Check(eq, kExpectedNativeContext);
}
// Check if both contexts are the same.
Ldr(scratch2, FieldMemOperand(holder_reg,
JSGlobalProxy::kNativeContextOffset));
Cmp(scratch1, scratch2);
B(&same_contexts, eq);
// Check the context is a native context.
if (emit_debug_code()) {
// We're short on scratch registers here, so use holder_reg as a scratch.
Push(holder_reg);
Register scratch3 = holder_reg;
CompareRoot(scratch2, Heap::kNullValueRootIndex);
Check(ne, kExpectedNonNullContext);
Ldr(scratch3, FieldMemOperand(scratch2, HeapObject::kMapOffset));
CompareRoot(scratch3, Heap::kNativeContextMapRootIndex);
Check(eq, kExpectedNativeContext);
Pop(holder_reg);
}
// Check that the security token in the calling global object is
// compatible with the security token in the receiving global
// object.
int token_offset = Context::kHeaderSize +
Context::SECURITY_TOKEN_INDEX * kPointerSize;
Ldr(scratch1, FieldMemOperand(scratch1, token_offset));
Ldr(scratch2, FieldMemOperand(scratch2, token_offset));
Cmp(scratch1, scratch2);
B(miss, ne);
Bind(&same_contexts);
}
// Compute the hash code from the untagged key. This must be kept in sync with
// ComputeIntegerHash in utils.h and KeyedLoadGenericStub in
// code-stub-hydrogen.cc
void MacroAssembler::GetNumberHash(Register key, Register scratch) {
DCHECK(!AreAliased(key, scratch));
// Xor original key with a seed.
LoadRoot(scratch, Heap::kHashSeedRootIndex);
Eor(key, key, Operand::UntagSmi(scratch));
// The algorithm uses 32-bit integer values.
key = key.W();
scratch = scratch.W();
// Compute the hash code from the untagged key. This must be kept in sync
// with ComputeIntegerHash in utils.h.
//
// hash = ~hash + (hash <<1 15);
Mvn(scratch, key);
Add(key, scratch, Operand(key, LSL, 15));
// hash = hash ^ (hash >> 12);
Eor(key, key, Operand(key, LSR, 12));
// hash = hash + (hash << 2);
Add(key, key, Operand(key, LSL, 2));
// hash = hash ^ (hash >> 4);
Eor(key, key, Operand(key, LSR, 4));
// hash = hash * 2057;
Mov(scratch, Operand(key, LSL, 11));
Add(key, key, Operand(key, LSL, 3));
Add(key, key, scratch);
// hash = hash ^ (hash >> 16);
Eor(key, key, Operand(key, LSR, 16));
}
void MacroAssembler::LoadFromNumberDictionary(Label* miss,
Register elements,
Register key,
Register result,
Register scratch0,
Register scratch1,
Register scratch2,
Register scratch3) {
DCHECK(!AreAliased(elements, key, scratch0, scratch1, scratch2, scratch3));
Label done;
SmiUntag(scratch0, key);
GetNumberHash(scratch0, scratch1);
// Compute the capacity mask.
Ldrsw(scratch1,
UntagSmiFieldMemOperand(elements,
SeededNumberDictionary::kCapacityOffset));
Sub(scratch1, scratch1, 1);
// Generate an unrolled loop that performs a few probes before giving up.
for (int i = 0; i < kNumberDictionaryProbes; i++) {
// Compute the masked index: (hash + i + i * i) & mask.
if (i > 0) {
Add(scratch2, scratch0, SeededNumberDictionary::GetProbeOffset(i));
} else {
Mov(scratch2, scratch0);
}
And(scratch2, scratch2, scratch1);
// Scale the index by multiplying by the element size.
DCHECK(SeededNumberDictionary::kEntrySize == 3);
Add(scratch2, scratch2, Operand(scratch2, LSL, 1));
// Check if the key is identical to the name.
Add(scratch2, elements, Operand(scratch2, LSL, kPointerSizeLog2));
Ldr(scratch3,
FieldMemOperand(scratch2,
SeededNumberDictionary::kElementsStartOffset));
Cmp(key, scratch3);
if (i != (kNumberDictionaryProbes - 1)) {
B(eq, &done);
} else {
B(ne, miss);
}
}
Bind(&done);
// Check that the value is a field property.
const int kDetailsOffset =
SeededNumberDictionary::kElementsStartOffset + 2 * kPointerSize;
Ldrsw(scratch1, UntagSmiFieldMemOperand(scratch2, kDetailsOffset));
DCHECK_EQ(FIELD, 0);
TestAndBranchIfAnySet(scratch1, PropertyDetails::TypeField::kMask, miss);
// Get the value at the masked, scaled index and return.
const int kValueOffset =
SeededNumberDictionary::kElementsStartOffset + kPointerSize;
Ldr(result, FieldMemOperand(scratch2, kValueOffset));
}
void MacroAssembler::RememberedSetHelper(Register object, // For debug tests.
Register address,
Register scratch1,
SaveFPRegsMode fp_mode,
RememberedSetFinalAction and_then) {
DCHECK(!AreAliased(object, address, scratch1));
Label done, store_buffer_overflow;
if (emit_debug_code()) {
Label ok;
JumpIfNotInNewSpace(object, &ok);
Abort(kRememberedSetPointerInNewSpace);
bind(&ok);
}
UseScratchRegisterScope temps(this);
Register scratch2 = temps.AcquireX();
// Load store buffer top.
Mov(scratch2, ExternalReference::store_buffer_top(isolate()));
Ldr(scratch1, MemOperand(scratch2));
// Store pointer to buffer and increment buffer top.
Str(address, MemOperand(scratch1, kPointerSize, PostIndex));
// Write back new top of buffer.
Str(scratch1, MemOperand(scratch2));
// Call stub on end of buffer.
// Check for end of buffer.
DCHECK(StoreBuffer::kStoreBufferOverflowBit ==
(1 << (14 + kPointerSizeLog2)));
if (and_then == kFallThroughAtEnd) {
Tbz(scratch1, (14 + kPointerSizeLog2), &done);
} else {
DCHECK(and_then == kReturnAtEnd);
Tbnz(scratch1, (14 + kPointerSizeLog2), &store_buffer_overflow);
Ret();
}
Bind(&store_buffer_overflow);
Push(lr);
StoreBufferOverflowStub store_buffer_overflow_stub(isolate(), fp_mode);
CallStub(&store_buffer_overflow_stub);
Pop(lr);
Bind(&done);
if (and_then == kReturnAtEnd) {
Ret();
}
}
void MacroAssembler::PopSafepointRegisters() {
const int num_unsaved = kNumSafepointRegisters - kNumSafepointSavedRegisters;
PopXRegList(kSafepointSavedRegisters);
Drop(num_unsaved);
}
void MacroAssembler::PushSafepointRegisters() {
// Safepoints expect a block of kNumSafepointRegisters values on the stack, so
// adjust the stack for unsaved registers.
const int num_unsaved = kNumSafepointRegisters - kNumSafepointSavedRegisters;
DCHECK(num_unsaved >= 0);
Claim(num_unsaved);
PushXRegList(kSafepointSavedRegisters);
}
void MacroAssembler::PushSafepointRegistersAndDoubles() {
PushSafepointRegisters();
PushCPURegList(CPURegList(CPURegister::kFPRegister, kDRegSizeInBits,
FPRegister::kAllocatableFPRegisters));
}
void MacroAssembler::PopSafepointRegistersAndDoubles() {
PopCPURegList(CPURegList(CPURegister::kFPRegister, kDRegSizeInBits,
FPRegister::kAllocatableFPRegisters));
PopSafepointRegisters();
}
int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
// Make sure the safepoint registers list is what we expect.
DCHECK(CPURegList::GetSafepointSavedRegisters().list() == 0x6ffcffff);
// Safepoint registers are stored contiguously on the stack, but not all the
// registers are saved. The following registers are excluded:
// - x16 and x17 (ip0 and ip1) because they shouldn't be preserved outside of
// the macro assembler.
// - x28 (jssp) because JS stack pointer doesn't need to be included in
// safepoint registers.
// - x31 (csp) because the system stack pointer doesn't need to be included
// in safepoint registers.
//
// This function implements the mapping of register code to index into the
// safepoint register slots.
if ((reg_code >= 0) && (reg_code <= 15)) {
return reg_code;
} else if ((reg_code >= 18) && (reg_code <= 27)) {
// Skip ip0 and ip1.
return reg_code - 2;
} else if ((reg_code == 29) || (reg_code == 30)) {
// Also skip jssp.
return reg_code - 3;
} else {
// This register has no safepoint register slot.
UNREACHABLE();
return -1;
}
}
void MacroAssembler::CheckPageFlagSet(const Register& object,
const Register& scratch,
int mask,
Label* if_any_set) {
And(scratch, object, ~Page::kPageAlignmentMask);
Ldr(scratch, MemOperand(scratch, MemoryChunk::kFlagsOffset));
TestAndBranchIfAnySet(scratch, mask, if_any_set);
}
void MacroAssembler::CheckPageFlagClear(const Register& object,
const Register& scratch,
int mask,
Label* if_all_clear) {
And(scratch, object, ~Page::kPageAlignmentMask);
Ldr(scratch, MemOperand(scratch, MemoryChunk::kFlagsOffset));
TestAndBranchIfAllClear(scratch, mask, if_all_clear);
}
void MacroAssembler::RecordWriteField(
Register object,
int offset,
Register value,
Register scratch,
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
SmiCheck smi_check,
PointersToHereCheck pointers_to_here_check_for_value) {
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis.
Label done;
// Skip the barrier if writing a smi.
if (smi_check == INLINE_SMI_CHECK) {
JumpIfSmi(value, &done);
}
// Although the object register is tagged, the offset is relative to the start
// of the object, so offset must be a multiple of kPointerSize.
DCHECK(IsAligned(offset, kPointerSize));
Add(scratch, object, offset - kHeapObjectTag);
if (emit_debug_code()) {
Label ok;
Tst(scratch, (1 << kPointerSizeLog2) - 1);
B(eq, &ok);
Abort(kUnalignedCellInWriteBarrier);
Bind(&ok);
}
RecordWrite(object,
scratch,
value,
lr_status,
save_fp,
remembered_set_action,
OMIT_SMI_CHECK,
pointers_to_here_check_for_value);
Bind(&done);
// Clobber clobbered input registers when running with the debug-code flag
// turned on to provoke errors.
if (emit_debug_code()) {
Mov(value, Operand(bit_cast<int64_t>(kZapValue + 4)));
Mov(scratch, Operand(bit_cast<int64_t>(kZapValue + 8)));
}
}
// Will clobber: object, map, dst.
// If lr_status is kLRHasBeenSaved, lr will also be clobbered.
void MacroAssembler::RecordWriteForMap(Register object,
Register map,
Register dst,
LinkRegisterStatus lr_status,
SaveFPRegsMode fp_mode) {
ASM_LOCATION("MacroAssembler::RecordWrite");
DCHECK(!AreAliased(object, map));
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
CompareObjectMap(map, temp, isolate()->factory()->meta_map());
Check(eq, kWrongAddressOrValuePassedToRecordWrite);
}
if (!FLAG_incremental_marking) {
return;
}
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
Cmp(temp, map);
Check(eq, kWrongAddressOrValuePassedToRecordWrite);
}
// First, check if a write barrier is even needed. The tests below
// catch stores of smis and stores into the young generation.
Label done;
// A single check of the map's pages interesting flag suffices, since it is
// only set during incremental collection, and then it's also guaranteed that
// the from object's page's interesting flag is also set. This optimization
// relies on the fact that maps can never be in new space.
CheckPageFlagClear(map,
map, // Used as scratch.
MemoryChunk::kPointersToHereAreInterestingMask,
&done);
// Record the actual write.
if (lr_status == kLRHasNotBeenSaved) {
Push(lr);
}
Add(dst, object, HeapObject::kMapOffset - kHeapObjectTag);
RecordWriteStub stub(isolate(), object, map, dst, OMIT_REMEMBERED_SET,
fp_mode);
CallStub(&stub);
if (lr_status == kLRHasNotBeenSaved) {
Pop(lr);
}
Bind(&done);
// Count number of write barriers in generated code.
isolate()->counters()->write_barriers_static()->Increment();
IncrementCounter(isolate()->counters()->write_barriers_dynamic(), 1, map,
dst);
// Clobber clobbered registers when running with the debug-code flag
// turned on to provoke errors.
if (emit_debug_code()) {
Mov(dst, Operand(bit_cast<int64_t>(kZapValue + 12)));
Mov(map, Operand(bit_cast<int64_t>(kZapValue + 16)));
}
}
// Will clobber: object, address, value.
// If lr_status is kLRHasBeenSaved, lr will also be clobbered.
//
// The register 'object' contains a heap object pointer. The heap object tag is
// shifted away.
void MacroAssembler::RecordWrite(
Register object,
Register address,
Register value,
LinkRegisterStatus lr_status,
SaveFPRegsMode fp_mode,
RememberedSetAction remembered_set_action,
SmiCheck smi_check,
PointersToHereCheck pointers_to_here_check_for_value) {
ASM_LOCATION("MacroAssembler::RecordWrite");
DCHECK(!AreAliased(object, value));
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ldr(temp, MemOperand(address));
Cmp(temp, value);
Check(eq, kWrongAddressOrValuePassedToRecordWrite);
}
// First, check if a write barrier is even needed. The tests below
// catch stores of smis and stores into the young generation.
Label done;
if (smi_check == INLINE_SMI_CHECK) {
DCHECK_EQ(0, kSmiTag);
JumpIfSmi(value, &done);
}
if (pointers_to_here_check_for_value != kPointersToHereAreAlwaysInteresting) {
CheckPageFlagClear(value,
value, // Used as scratch.
MemoryChunk::kPointersToHereAreInterestingMask,
&done);
}
CheckPageFlagClear(object,
value, // Used as scratch.
MemoryChunk::kPointersFromHereAreInterestingMask,
&done);
// Record the actual write.
if (lr_status == kLRHasNotBeenSaved) {
Push(lr);
}
RecordWriteStub stub(isolate(), object, value, address, remembered_set_action,
fp_mode);
CallStub(&stub);
if (lr_status == kLRHasNotBeenSaved) {
Pop(lr);
}
Bind(&done);
// Count number of write barriers in generated code.
isolate()->counters()->write_barriers_static()->Increment();
IncrementCounter(isolate()->counters()->write_barriers_dynamic(), 1, address,
value);
// Clobber clobbered registers when running with the debug-code flag
// turned on to provoke errors.
if (emit_debug_code()) {
Mov(address, Operand(bit_cast<int64_t>(kZapValue + 12)));
Mov(value, Operand(bit_cast<int64_t>(kZapValue + 16)));
}
}
void MacroAssembler::AssertHasValidColor(const Register& reg) {
if (emit_debug_code()) {
// The bit sequence is backward. The first character in the string
// represents the least significant bit.
DCHECK(strcmp(Marking::kImpossibleBitPattern, "01") == 0);
Label color_is_valid;
Tbnz(reg, 0, &color_is_valid);
Tbz(reg, 1, &color_is_valid);
Abort(kUnexpectedColorFound);
Bind(&color_is_valid);
}
}
void MacroAssembler::GetMarkBits(Register addr_reg,
Register bitmap_reg,
Register shift_reg) {
DCHECK(!AreAliased(addr_reg, bitmap_reg, shift_reg));
DCHECK(addr_reg.Is64Bits() && bitmap_reg.Is64Bits() && shift_reg.Is64Bits());
// addr_reg is divided into fields:
// |63 page base 20|19 high 8|7 shift 3|2 0|
// 'high' gives the index of the cell holding color bits for the object.
// 'shift' gives the offset in the cell for this object's color.
const int kShiftBits = kPointerSizeLog2 + Bitmap::kBitsPerCellLog2;
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Ubfx(temp, addr_reg, kShiftBits, kPageSizeBits - kShiftBits);
Bic(bitmap_reg, addr_reg, Page::kPageAlignmentMask);
Add(bitmap_reg, bitmap_reg, Operand(temp, LSL, Bitmap::kBytesPerCellLog2));
// bitmap_reg:
// |63 page base 20|19 zeros 15|14 high 3|2 0|
Ubfx(shift_reg, addr_reg, kPointerSizeLog2, Bitmap::kBitsPerCellLog2);
}
void MacroAssembler::HasColor(Register object,
Register bitmap_scratch,
Register shift_scratch,
Label* has_color,
int first_bit,
int second_bit) {
// See mark-compact.h for color definitions.
DCHECK(!AreAliased(object, bitmap_scratch, shift_scratch));
GetMarkBits(object, bitmap_scratch, shift_scratch);
Ldr(bitmap_scratch, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
// Shift the bitmap down to get the color of the object in bits [1:0].
Lsr(bitmap_scratch, bitmap_scratch, shift_scratch);
AssertHasValidColor(bitmap_scratch);
// These bit sequences are backwards. The first character in the string
// represents the least significant bit.
DCHECK(strcmp(Marking::kWhiteBitPattern, "00") == 0);
DCHECK(strcmp(Marking::kBlackBitPattern, "10") == 0);
DCHECK(strcmp(Marking::kGreyBitPattern, "11") == 0);
// Check for the color.
if (first_bit == 0) {
// Checking for white.
DCHECK(second_bit == 0);
// We only need to test the first bit.
Tbz(bitmap_scratch, 0, has_color);
} else {
Label other_color;
// Checking for grey or black.
Tbz(bitmap_scratch, 0, &other_color);
if (second_bit == 0) {
Tbz(bitmap_scratch, 1, has_color);
} else {
Tbnz(bitmap_scratch, 1, has_color);
}
Bind(&other_color);
}
// Fall through if it does not have the right color.
}
void MacroAssembler::JumpIfBlack(Register object,
Register scratch0,
Register scratch1,
Label* on_black) {
DCHECK(strcmp(Marking::kBlackBitPattern, "10") == 0);
HasColor(object, scratch0, scratch1, on_black, 1, 0); // kBlackBitPattern.
}
void MacroAssembler::JumpIfDictionaryInPrototypeChain(
Register object,
Register scratch0,
Register scratch1,
Label* found) {
DCHECK(!AreAliased(object, scratch0, scratch1));
Factory* factory = isolate()->factory();
Register current = scratch0;
Label loop_again;
// Scratch contains elements pointer.
Mov(current, object);
// Loop based on the map going up the prototype chain.
Bind(&loop_again);
Ldr(current, FieldMemOperand(current, HeapObject::kMapOffset));
Ldrb(scratch1, FieldMemOperand(current, Map::kBitField2Offset));
DecodeField<Map::ElementsKindBits>(scratch1);
CompareAndBranch(scratch1, DICTIONARY_ELEMENTS, eq, found);
Ldr(current, FieldMemOperand(current, Map::kPrototypeOffset));
CompareAndBranch(current, Operand(factory->null_value()), ne, &loop_again);
}
void MacroAssembler::GetRelocatedValueLocation(Register ldr_location,
Register result) {
DCHECK(!result.Is(ldr_location));
const uint32_t kLdrLitOffset_lsb = 5;
const uint32_t kLdrLitOffset_width = 19;
Ldr(result, MemOperand(ldr_location));
if (emit_debug_code()) {
And(result, result, LoadLiteralFMask);
Cmp(result, LoadLiteralFixed);
Check(eq, kTheInstructionToPatchShouldBeAnLdrLiteral);
// The instruction was clobbered. Reload it.
Ldr(result, MemOperand(ldr_location));
}
Sbfx(result, result, kLdrLitOffset_lsb, kLdrLitOffset_width);
Add(result, ldr_location, Operand(result, LSL, kWordSizeInBytesLog2));
}
void MacroAssembler::EnsureNotWhite(
Register value,
Register bitmap_scratch,
Register shift_scratch,
Register load_scratch,
Register length_scratch,
Label* value_is_white_and_not_data) {
DCHECK(!AreAliased(
value, bitmap_scratch, shift_scratch, load_scratch, length_scratch));
// These bit sequences are backwards. The first character in the string
// represents the least significant bit.
DCHECK(strcmp(Marking::kWhiteBitPattern, "00") == 0);
DCHECK(strcmp(Marking::kBlackBitPattern, "10") == 0);
DCHECK(strcmp(Marking::kGreyBitPattern, "11") == 0);
GetMarkBits(value, bitmap_scratch, shift_scratch);
Ldr(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
Lsr(load_scratch, load_scratch, shift_scratch);
AssertHasValidColor(load_scratch);
// If the value is black or grey we don't need to do anything.
// Since both black and grey have a 1 in the first position and white does
// not have a 1 there we only need to check one bit.
Label done;
Tbnz(load_scratch, 0, &done);
// Value is white. We check whether it is data that doesn't need scanning.
Register map = load_scratch; // Holds map while checking type.
Label is_data_object;
// Check for heap-number.
Ldr(map, FieldMemOperand(value, HeapObject::kMapOffset));
Mov(length_scratch, HeapNumber::kSize);
JumpIfRoot(map, Heap::kHeapNumberMapRootIndex, &is_data_object);
// Check for strings.
DCHECK(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
DCHECK(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
// If it's a string and it's not a cons string then it's an object containing
// no GC pointers.
Register instance_type = load_scratch;
Ldrb(instance_type, FieldMemOperand(map, Map::kInstanceTypeOffset));
TestAndBranchIfAnySet(instance_type,
kIsIndirectStringMask | kIsNotStringMask,
value_is_white_and_not_data);
// It's a non-indirect (non-cons and non-slice) string.
// If it's external, the length is just ExternalString::kSize.
// Otherwise it's String::kHeaderSize + string->length() * (1 or 2).
// External strings are the only ones with the kExternalStringTag bit
// set.
DCHECK_EQ(0, kSeqStringTag & kExternalStringTag);
DCHECK_EQ(0, kConsStringTag & kExternalStringTag);
Mov(length_scratch, ExternalString::kSize);
TestAndBranchIfAnySet(instance_type, kExternalStringTag, &is_data_object);
// Sequential string, either Latin1 or UC16.
// For Latin1 (char-size of 1) we shift the smi tag away to get the length.
// For UC16 (char-size of 2) we just leave the smi tag in place, thereby
// getting the length multiplied by 2.
DCHECK(kOneByteStringTag == 4 && kStringEncodingMask == 4);
Ldrsw(length_scratch, UntagSmiFieldMemOperand(value,
String::kLengthOffset));
Tst(instance_type, kStringEncodingMask);
Cset(load_scratch, eq);
Lsl(length_scratch, length_scratch, load_scratch);
Add(length_scratch,
length_scratch,
SeqString::kHeaderSize + kObjectAlignmentMask);
Bic(length_scratch, length_scratch, kObjectAlignmentMask);
Bind(&is_data_object);
// Value is a data object, and it is white. Mark it black. Since we know
// that the object is white we can make it black by flipping one bit.
Register mask = shift_scratch;
Mov(load_scratch, 1);
Lsl(mask, load_scratch, shift_scratch);
Ldr(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
Orr(load_scratch, load_scratch, mask);
Str(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
Bic(bitmap_scratch, bitmap_scratch, Page::kPageAlignmentMask);
Ldr(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
Add(load_scratch, load_scratch, length_scratch);
Str(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
Bind(&done);
}
void MacroAssembler::Assert(Condition cond, BailoutReason reason) {
if (emit_debug_code()) {
Check(cond, reason);
}
}
void MacroAssembler::AssertRegisterIsClear(Register reg, BailoutReason reason) {
if (emit_debug_code()) {
CheckRegisterIsClear(reg, reason);
}
}
void MacroAssembler::AssertRegisterIsRoot(Register reg,
Heap::RootListIndex index,
BailoutReason reason) {
if (emit_debug_code()) {
CompareRoot(reg, index);
Check(eq, reason);
}
}
void MacroAssembler::AssertFastElements(Register elements) {
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Label ok;
Ldr(temp, FieldMemOperand(elements, HeapObject::kMapOffset));
JumpIfRoot(temp, Heap::kFixedArrayMapRootIndex, &ok);
JumpIfRoot(temp, Heap::kFixedDoubleArrayMapRootIndex, &ok);
JumpIfRoot(temp, Heap::kFixedCOWArrayMapRootIndex, &ok);
Abort(kJSObjectWithFastElementsMapHasSlowElements);
Bind(&ok);
}
}
void MacroAssembler::AssertIsString(const Register& object) {
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
STATIC_ASSERT(kSmiTag == 0);
Tst(object, kSmiTagMask);
Check(ne, kOperandIsNotAString);
Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
CompareInstanceType(temp, temp, FIRST_NONSTRING_TYPE);
Check(lo, kOperandIsNotAString);
}
}
void MacroAssembler::Check(Condition cond, BailoutReason reason) {
Label ok;
B(cond, &ok);
Abort(reason);
// Will not return here.
Bind(&ok);
}
void MacroAssembler::CheckRegisterIsClear(Register reg, BailoutReason reason) {
Label ok;
Cbz(reg, &ok);
Abort(reason);
// Will not return here.
Bind(&ok);
}
void MacroAssembler::Abort(BailoutReason reason) {
#ifdef DEBUG
RecordComment("Abort message: ");
RecordComment(GetBailoutReason(reason));
if (FLAG_trap_on_abort) {
Brk(0);
return;
}
#endif
// Abort is used in some contexts where csp is the stack pointer. In order to
// simplify the CallRuntime code, make sure that jssp is the stack pointer.
// There is no risk of register corruption here because Abort doesn't return.
Register old_stack_pointer = StackPointer();
SetStackPointer(jssp);
Mov(jssp, old_stack_pointer);
// We need some scratch registers for the MacroAssembler, so make sure we have
// some. This is safe here because Abort never returns.
RegList old_tmp_list = TmpList()->list();
TmpList()->Combine(MacroAssembler::DefaultTmpList());
if (use_real_aborts()) {
// Avoid infinite recursion; Push contains some assertions that use Abort.
NoUseRealAbortsScope no_real_aborts(this);
Mov(x0, Smi::FromInt(reason));
Push(x0);
if (!has_frame_) {
// We don't actually want to generate a pile of code for this, so just
// claim there is a stack frame, without generating one.
FrameScope scope(this, StackFrame::NONE);
CallRuntime(Runtime::kAbort, 1);
} else {
CallRuntime(Runtime::kAbort, 1);
}
} else {
// Load the string to pass to Printf.
Label msg_address;
Adr(x0, &msg_address);
// Call Printf directly to report the error.
CallPrintf();
// We need a way to stop execution on both the simulator and real hardware,
// and Unreachable() is the best option.
Unreachable();
// Emit the message string directly in the instruction stream.
{
BlockPoolsScope scope(this);
Bind(&msg_address);
EmitStringData(GetBailoutReason(reason));
}
}
SetStackPointer(old_stack_pointer);
TmpList()->set_list(old_tmp_list);
}
void MacroAssembler::LoadTransitionedArrayMapConditional(
ElementsKind expected_kind,
ElementsKind transitioned_kind,
Register map_in_out,
Register scratch1,
Register scratch2,
Label* no_map_match) {
// Load the global or builtins object from the current context.
Ldr(scratch1, GlobalObjectMemOperand());
Ldr(scratch1, FieldMemOperand(scratch1, GlobalObject::kNativeContextOffset));
// Check that the function's map is the same as the expected cached map.
Ldr(scratch1, ContextMemOperand(scratch1, Context::JS_ARRAY_MAPS_INDEX));
size_t offset = (expected_kind * kPointerSize) + FixedArrayBase::kHeaderSize;
Ldr(scratch2, FieldMemOperand(scratch1, offset));
Cmp(map_in_out, scratch2);
B(ne, no_map_match);
// Use the transitioned cached map.
offset = (transitioned_kind * kPointerSize) + FixedArrayBase::kHeaderSize;
Ldr(map_in_out, FieldMemOperand(scratch1, offset));
}
void MacroAssembler::LoadGlobalFunction(int index, Register function) {
// Load the global or builtins object from the current context.
Ldr(function, GlobalObjectMemOperand());
// Load the native context from the global or builtins object.
Ldr(function, FieldMemOperand(function,
GlobalObject::kNativeContextOffset));
// Load the function from the native context.
Ldr(function, ContextMemOperand(function, index));
}
void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
Register map,
Register scratch) {
// Load the initial map. The global functions all have initial maps.
Ldr(map, FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
if (emit_debug_code()) {
Label ok, fail;
CheckMap(map, scratch, Heap::kMetaMapRootIndex, &fail, DO_SMI_CHECK);
B(&ok);
Bind(&fail);
Abort(kGlobalFunctionsMustHaveInitialMap);
Bind(&ok);
}
}
// This is the main Printf implementation. All other Printf variants call
// PrintfNoPreserve after setting up one or more PreserveRegisterScopes.
void MacroAssembler::PrintfNoPreserve(const char * format,
const CPURegister& arg0,
const CPURegister& arg1,
const CPURegister& arg2,
const CPURegister& arg3) {
// We cannot handle a caller-saved stack pointer. It doesn't make much sense
// in most cases anyway, so this restriction shouldn't be too serious.
DCHECK(!kCallerSaved.IncludesAliasOf(__ StackPointer()));
// The provided arguments, and their proper procedure-call standard registers.
CPURegister args[kPrintfMaxArgCount] = {arg0, arg1, arg2, arg3};
CPURegister pcs[kPrintfMaxArgCount] = {NoReg, NoReg, NoReg, NoReg};
int arg_count = kPrintfMaxArgCount;
// The PCS varargs registers for printf. Note that x0 is used for the printf
// format string.
static const CPURegList kPCSVarargs =
CPURegList(CPURegister::kRegister, kXRegSizeInBits, 1, arg_count);
static const CPURegList kPCSVarargsFP =
CPURegList(CPURegister::kFPRegister, kDRegSizeInBits, 0, arg_count - 1);
// We can use caller-saved registers as scratch values, except for the
// arguments and the PCS registers where they might need to go.
CPURegList tmp_list = kCallerSaved;
tmp_list.Remove(x0); // Used to pass the format string.
tmp_list.Remove(kPCSVarargs);
tmp_list.Remove(arg0, arg1, arg2, arg3);
CPURegList fp_tmp_list = kCallerSavedFP;
fp_tmp_list.Remove(kPCSVarargsFP);
fp_tmp_list.Remove(arg0, arg1, arg2, arg3);
// Override the MacroAssembler's scratch register list. The lists will be
// reset automatically at the end of the UseScratchRegisterScope.
UseScratchRegisterScope temps(this);
TmpList()->set_list(tmp_list.list());
FPTmpList()->set_list(fp_tmp_list.list());
// Copies of the printf vararg registers that we can pop from.
CPURegList pcs_varargs = kPCSVarargs;
CPURegList pcs_varargs_fp = kPCSVarargsFP;
// Place the arguments. There are lots of clever tricks and optimizations we
// could use here, but Printf is a debug tool so instead we just try to keep
// it simple: Move each input that isn't already in the right place to a
// scratch register, then move everything back.
for (unsigned i = 0; i < kPrintfMaxArgCount; i++) {
// Work out the proper PCS register for this argument.
if (args[i].IsRegister()) {
pcs[i] = pcs_varargs.PopLowestIndex().X();
// We might only need a W register here. We need to know the size of the
// argument so we can properly encode it for the simulator call.
if (args[i].Is32Bits()) pcs[i] = pcs[i].W();
} else if (args[i].IsFPRegister()) {
// In C, floats are always cast to doubles for varargs calls.
pcs[i] = pcs_varargs_fp.PopLowestIndex().D();
} else {
DCHECK(args[i].IsNone());
arg_count = i;
break;
}
// If the argument is already in the right place, leave it where it is.
if (args[i].Aliases(pcs[i])) continue;
// Otherwise, if the argument is in a PCS argument register, allocate an
// appropriate scratch register and then move it out of the way.
if (kPCSVarargs.IncludesAliasOf(args[i]) ||
kPCSVarargsFP.IncludesAliasOf(args[i])) {
if (args[i].IsRegister()) {
Register old_arg = Register(args[i]);
Register new_arg = temps.AcquireSameSizeAs(old_arg);
Mov(new_arg, old_arg);
args[i] = new_arg;
} else {
FPRegister old_arg = FPRegister(args[i]);
FPRegister new_arg = temps.AcquireSameSizeAs(old_arg);
Fmov(new_arg, old_arg);
args[i] = new_arg;
}
}
}
// Do a second pass to move values into their final positions and perform any
// conversions that may be required.
for (int i = 0; i < arg_count; i++) {
DCHECK(pcs[i].type() == args[i].type());
if (pcs[i].IsRegister()) {
Mov(Register(pcs[i]), Register(args[i]), kDiscardForSameWReg);
} else {
DCHECK(pcs[i].IsFPRegister());
if (pcs[i].SizeInBytes() == args[i].SizeInBytes()) {
Fmov(FPRegister(pcs[i]), FPRegister(args[i]));
} else {
Fcvt(FPRegister(pcs[i]), FPRegister(args[i]));
}
}
}
// Load the format string into x0, as per the procedure-call standard.
//
// To make the code as portable as possible, the format string is encoded
// directly in the instruction stream. It might be cleaner to encode it in a
// literal pool, but since Printf is usually used for debugging, it is
// beneficial for it to be minimally dependent on other features.
Label format_address;
Adr(x0, &format_address);
// Emit the format string directly in the instruction stream.
{ BlockPoolsScope scope(this);
Label after_data;
B(&after_data);
Bind(&format_address);
EmitStringData(format);
Unreachable();
Bind(&after_data);
}
// We don't pass any arguments on the stack, but we still need to align the C
// stack pointer to a 16-byte boundary for PCS compliance.
if (!csp.Is(StackPointer())) {
Bic(csp, StackPointer(), 0xf);
}
CallPrintf(arg_count, pcs);
}
void MacroAssembler::CallPrintf(int arg_count, const CPURegister * args) {
// A call to printf needs special handling for the simulator, since the system
// printf function will use a different instruction set and the procedure-call
// standard will not be compatible.
#ifdef USE_SIMULATOR
{ InstructionAccurateScope scope(this, kPrintfLength / kInstructionSize);
hlt(kImmExceptionIsPrintf);
dc32(arg_count); // kPrintfArgCountOffset
// Determine the argument pattern.
uint32_t arg_pattern_list = 0;
for (int i = 0; i < arg_count; i++) {
uint32_t arg_pattern;
if (args[i].IsRegister()) {
arg_pattern = args[i].Is32Bits() ? kPrintfArgW : kPrintfArgX;
} else {
DCHECK(args[i].Is64Bits());
arg_pattern = kPrintfArgD;
}
DCHECK(arg_pattern < (1 << kPrintfArgPatternBits));
arg_pattern_list |= (arg_pattern << (kPrintfArgPatternBits * i));
}
dc32(arg_pattern_list); // kPrintfArgPatternListOffset
}
#else
Call(FUNCTION_ADDR(printf), RelocInfo::EXTERNAL_REFERENCE);
#endif
}
void MacroAssembler::Printf(const char * format,
CPURegister arg0,
CPURegister arg1,
CPURegister arg2,
CPURegister arg3) {
// We can only print sp if it is the current stack pointer.
if (!csp.Is(StackPointer())) {
DCHECK(!csp.Aliases(arg0));
DCHECK(!csp.Aliases(arg1));
DCHECK(!csp.Aliases(arg2));
DCHECK(!csp.Aliases(arg3));
}
// Printf is expected to preserve all registers, so make sure that none are
// available as scratch registers until we've preserved them.
RegList old_tmp_list = TmpList()->list();
RegList old_fp_tmp_list = FPTmpList()->list();
TmpList()->set_list(0);
FPTmpList()->set_list(0);
// Preserve all caller-saved registers as well as NZCV.
// If csp is the stack pointer, PushCPURegList asserts that the size of each
// list is a multiple of 16 bytes.
PushCPURegList(kCallerSaved);
PushCPURegList(kCallerSavedFP);
// We can use caller-saved registers as scratch values (except for argN).
CPURegList tmp_list = kCallerSaved;
CPURegList fp_tmp_list = kCallerSavedFP;
tmp_list.Remove(arg0, arg1, arg2, arg3);
fp_tmp_list.Remove(arg0, arg1, arg2, arg3);
TmpList()->set_list(tmp_list.list());
FPTmpList()->set_list(fp_tmp_list.list());
{ UseScratchRegisterScope temps(this);
// If any of the arguments are the current stack pointer, allocate a new
// register for them, and adjust the value to compensate for pushing the
// caller-saved registers.
bool arg0_sp = StackPointer().Aliases(arg0);
bool arg1_sp = StackPointer().Aliases(arg1);
bool arg2_sp = StackPointer().Aliases(arg2);
bool arg3_sp = StackPointer().Aliases(arg3);
if (arg0_sp || arg1_sp || arg2_sp || arg3_sp) {
// Allocate a register to hold the original stack pointer value, to pass
// to PrintfNoPreserve as an argument.
Register arg_sp = temps.AcquireX();
Add(arg_sp, StackPointer(),
kCallerSaved.TotalSizeInBytes() + kCallerSavedFP.TotalSizeInBytes());
if (arg0_sp) arg0 = Register::Create(arg_sp.code(), arg0.SizeInBits());
if (arg1_sp) arg1 = Register::Create(arg_sp.code(), arg1.SizeInBits());
if (arg2_sp) arg2 = Register::Create(arg_sp.code(), arg2.SizeInBits());
if (arg3_sp) arg3 = Register::Create(arg_sp.code(), arg3.SizeInBits());
}
// Preserve NZCV.
{ UseScratchRegisterScope temps(this);
Register tmp = temps.AcquireX();
Mrs(tmp, NZCV);
Push(tmp, xzr);
}
PrintfNoPreserve(format, arg0, arg1, arg2, arg3);
// Restore NZCV.
{ UseScratchRegisterScope temps(this);
Register tmp = temps.AcquireX();
Pop(xzr, tmp);
Msr(NZCV, tmp);
}
}
PopCPURegList(kCallerSavedFP);
PopCPURegList(kCallerSaved);
TmpList()->set_list(old_tmp_list);
FPTmpList()->set_list(old_fp_tmp_list);
}
void MacroAssembler::EmitFrameSetupForCodeAgePatching() {
// TODO(jbramley): Other architectures use the internal memcpy to copy the
// sequence. If this is a performance bottleneck, we should consider caching
// the sequence and copying it in the same way.
InstructionAccurateScope scope(this,
kNoCodeAgeSequenceLength / kInstructionSize);
DCHECK(jssp.Is(StackPointer()));
EmitFrameSetupForCodeAgePatching(this);
}
void MacroAssembler::EmitCodeAgeSequence(Code* stub) {
InstructionAccurateScope scope(this,
kNoCodeAgeSequenceLength / kInstructionSize);
DCHECK(jssp.Is(StackPointer()));
EmitCodeAgeSequence(this, stub);
}
#undef __
#define __ assm->
void MacroAssembler::EmitFrameSetupForCodeAgePatching(Assembler * assm) {
Label start;
__ bind(&start);
// We can do this sequence using four instructions, but the code ageing
// sequence that patches it needs five, so we use the extra space to try to
// simplify some addressing modes and remove some dependencies (compared to
// using two stp instructions with write-back).
__ sub(jssp, jssp, 4 * kXRegSize);
__ sub(csp, csp, 4 * kXRegSize);
__ stp(x1, cp, MemOperand(jssp, 0 * kXRegSize));
__ stp(fp, lr, MemOperand(jssp, 2 * kXRegSize));
__ add(fp, jssp, StandardFrameConstants::kFixedFrameSizeFromFp);
__ AssertSizeOfCodeGeneratedSince(&start, kNoCodeAgeSequenceLength);
}
void MacroAssembler::EmitCodeAgeSequence(Assembler * assm,
Code * stub) {
Label start;
__ bind(&start);
// When the stub is called, the sequence is replaced with the young sequence
// (as in EmitFrameSetupForCodeAgePatching). After the code is replaced, the
// stub jumps to &start, stored in x0. The young sequence does not call the
// stub so there is no infinite loop here.
//
// A branch (br) is used rather than a call (blr) because this code replaces
// the frame setup code that would normally preserve lr.
__ ldr_pcrel(ip0, kCodeAgeStubEntryOffset >> kLoadLiteralScaleLog2);
__ adr(x0, &start);
__ br(ip0);
// IsCodeAgeSequence in codegen-arm64.cc assumes that the code generated up
// until now (kCodeAgeStubEntryOffset) is the same for all code age sequences.
__ AssertSizeOfCodeGeneratedSince(&start, kCodeAgeStubEntryOffset);
if (stub) {
__ dc64(reinterpret_cast<uint64_t>(stub->instruction_start()));
__ AssertSizeOfCodeGeneratedSince(&start, kNoCodeAgeSequenceLength);
}
}
bool MacroAssembler::IsYoungSequence(Isolate* isolate, byte* sequence) {
bool is_young = isolate->code_aging_helper()->IsYoung(sequence);
DCHECK(is_young ||
isolate->code_aging_helper()->IsOld(sequence));
return is_young;
}
void MacroAssembler::TruncatingDiv(Register result,
Register dividend,
int32_t divisor) {
DCHECK(!AreAliased(result, dividend));
DCHECK(result.Is32Bits() && dividend.Is32Bits());
base::MagicNumbersForDivision<uint32_t> mag =
base::SignedDivisionByConstant(static_cast<uint32_t>(divisor));
Mov(result, mag.multiplier);
Smull(result.X(), dividend, result);
Asr(result.X(), result.X(), 32);
bool neg = (mag.multiplier & (static_cast<uint32_t>(1) << 31)) != 0;
if (divisor > 0 && neg) Add(result, result, dividend);
if (divisor < 0 && !neg && mag.multiplier > 0) Sub(result, result, dividend);
if (mag.shift > 0) Asr(result, result, mag.shift);
Add(result, result, Operand(dividend, LSR, 31));
}
#undef __
UseScratchRegisterScope::~UseScratchRegisterScope() {
available_->set_list(old_available_);
availablefp_->set_list(old_availablefp_);
}
Register UseScratchRegisterScope::AcquireSameSizeAs(const Register& reg) {
int code = AcquireNextAvailable(available_).code();
return Register::Create(code, reg.SizeInBits());
}
FPRegister UseScratchRegisterScope::AcquireSameSizeAs(const FPRegister& reg) {
int code = AcquireNextAvailable(availablefp_).code();
return FPRegister::Create(code, reg.SizeInBits());
}
CPURegister UseScratchRegisterScope::AcquireNextAvailable(
CPURegList* available) {
CHECK(!available->IsEmpty());
CPURegister result = available->PopLowestIndex();
DCHECK(!AreAliased(result, xzr, csp));
return result;
}
CPURegister UseScratchRegisterScope::UnsafeAcquire(CPURegList* available,
const CPURegister& reg) {
DCHECK(available->IncludesAliasOf(reg));
available->Remove(reg);
return reg;
}
#define __ masm->
void InlineSmiCheckInfo::Emit(MacroAssembler* masm, const Register& reg,
const Label* smi_check) {
Assembler::BlockPoolsScope scope(masm);
if (reg.IsValid()) {
DCHECK(smi_check->is_bound());
DCHECK(reg.Is64Bits());
// Encode the register (x0-x30) in the lowest 5 bits, then the offset to
// 'check' in the other bits. The possible offset is limited in that we
// use BitField to pack the data, and the underlying data type is a
// uint32_t.
uint32_t delta = __ InstructionsGeneratedSince(smi_check);
__ InlineData(RegisterBits::encode(reg.code()) | DeltaBits::encode(delta));
} else {
DCHECK(!smi_check->is_bound());
// An offset of 0 indicates that there is no patch site.
__ InlineData(0);
}
}
InlineSmiCheckInfo::InlineSmiCheckInfo(Address info)
: reg_(NoReg), smi_check_(NULL) {
InstructionSequence* inline_data = InstructionSequence::At(info);
DCHECK(inline_data->IsInlineData());
if (inline_data->IsInlineData()) {
uint64_t payload = inline_data->InlineData();
// We use BitField to decode the payload, and BitField can only handle
// 32-bit values.
DCHECK(is_uint32(payload));
if (payload != 0) {
int reg_code = RegisterBits::decode(payload);
reg_ = Register::XRegFromCode(reg_code);
uint64_t smi_check_delta = DeltaBits::decode(payload);
DCHECK(smi_check_delta != 0);
smi_check_ = inline_data->preceding(smi_check_delta);
}
}
}
#undef __
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_ARM64