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cobalt / cobalt / 63c7ad499be49ef959b3b1c5ea3f48491aa033d3 / . / src / v8 / src / codegen / 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.
#if V8_TARGET_ARCH_ARM64
#include "src/base/bits.h"
#include "src/base/division-by-constant.h"
#include "src/codegen/assembler.h"
#include "src/codegen/callable.h"
#include "src/codegen/code-factory.h"
#include "src/codegen/external-reference-table.h"
#include "src/codegen/macro-assembler-inl.h"
#include "src/codegen/register-configuration.h"
#include "src/debug/debug.h"
#include "src/execution/frame-constants.h"
#include "src/execution/frames-inl.h"
#include "src/heap/heap-inl.h" // For MemoryChunk.
#include "src/init/bootstrapper.h"
#include "src/logging/counters.h"
#include "src/runtime/runtime.h"
#include "src/snapshot/embedded/embedded-data.h"
#include "src/snapshot/snapshot.h"
#include "src/wasm/wasm-code-manager.h"
// Satisfy cpplint check, but don't include platform-specific header. It is
// included recursively via macro-assembler.h.
#if 0
#include "src/codegen/arm64/macro-assembler-arm64.h"
#endif
namespace v8 {
namespace internal {
CPURegList TurboAssembler::DefaultTmpList() { return CPURegList(ip0, ip1); }
CPURegList TurboAssembler::DefaultFPTmpList() {
return CPURegList(fp_scratch1, fp_scratch2);
}
int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
Register exclusion) const {
auto list = kCallerSaved;
list.Remove(exclusion);
list.Align();
int bytes = list.Count() * kXRegSizeInBits / 8;
if (fp_mode == kSaveFPRegs) {
DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
bytes += kCallerSavedV.Count() * kDRegSizeInBits / 8;
}
return bytes;
}
int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode,
Register exclusion) {
auto list = kCallerSaved;
list.Remove(exclusion);
list.Align();
PushCPURegList(list);
int bytes = list.Count() * kXRegSizeInBits / 8;
if (fp_mode == kSaveFPRegs) {
DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
PushCPURegList(kCallerSavedV);
bytes += kCallerSavedV.Count() * kDRegSizeInBits / 8;
}
return bytes;
}
int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion) {
int bytes = 0;
if (fp_mode == kSaveFPRegs) {
DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
PopCPURegList(kCallerSavedV);
bytes += kCallerSavedV.Count() * kDRegSizeInBits / 8;
}
auto list = kCallerSaved;
list.Remove(exclusion);
list.Align();
PopCPURegList(list);
bytes += list.Count() * kXRegSizeInBits / 8;
return bytes;
}
void TurboAssembler::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);
// If the left-hand input is the stack pointer, we can't pre-shift the
// immediate, as the encoding won't allow the subsequent post shift.
PreShiftImmMode mode = rn.Is(sp) ? kNoShift : kAnyShift;
Operand imm_operand = MoveImmediateForShiftedOp(temp, immediate, mode);
if (rd.IsSP()) {
// 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(sp, temp);
} 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_LE(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 TurboAssembler::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_EQ(reg_size % 16, 0);
bool first_mov_done = false;
for (int 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);
}
}
}
void TurboAssembler::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)) {
if (FLAG_embedded_builtins) {
if (root_array_available_ && options().isolate_independent_code) {
if (operand.ImmediateRMode() == RelocInfo::EXTERNAL_REFERENCE) {
Address addr = static_cast<Address>(operand.ImmediateValue());
ExternalReference reference = bit_cast<ExternalReference>(addr);
IndirectLoadExternalReference(rd, reference);
return;
} else if (RelocInfo::IsEmbeddedObjectMode(operand.ImmediateRMode())) {
Handle<HeapObject> x(
reinterpret_cast<Address*>(operand.ImmediateValue()));
IndirectLoadConstant(rd, x);
return;
}
}
}
Ldr(dst, operand);
} 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 sp 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 TurboAssembler::Mov(const Register& rd, Smi smi) {
return Mov(rd, Operand(smi));
}
void TurboAssembler::Movi16bitHelper(const VRegister& vd, uint64_t imm) {
DCHECK(is_uint16(imm));
int byte1 = (imm & 0xFF);
int byte2 = ((imm >> 8) & 0xFF);
if (byte1 == byte2) {
movi(vd.Is64Bits() ? vd.V8B() : vd.V16B(), byte1);
} else if (byte1 == 0) {
movi(vd, byte2, LSL, 8);
} else if (byte2 == 0) {
movi(vd, byte1);
} else if (byte1 == 0xFF) {
mvni(vd, ~byte2 & 0xFF, LSL, 8);
} else if (byte2 == 0xFF) {
mvni(vd, ~byte1 & 0xFF);
} else {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireW();
movz(temp, imm);
dup(vd, temp);
}
}
void TurboAssembler::Movi32bitHelper(const VRegister& vd, uint64_t imm) {
DCHECK(is_uint32(imm));
uint8_t bytes[sizeof(imm)];
memcpy(bytes, &imm, sizeof(imm));
// All bytes are either 0x00 or 0xFF.
{
bool all0orff = true;
for (int i = 0; i < 4; ++i) {
if ((bytes[i] != 0) && (bytes[i] != 0xFF)) {
all0orff = false;
break;
}
}
if (all0orff == true) {
movi(vd.Is64Bits() ? vd.V1D() : vd.V2D(), ((imm << 32) | imm));
return;
}
}
// Of the 4 bytes, only one byte is non-zero.
for (int i = 0; i < 4; i++) {
if ((imm & (0xFF << (i * 8))) == imm) {
movi(vd, bytes[i], LSL, i * 8);
return;
}
}
// Of the 4 bytes, only one byte is not 0xFF.
for (int i = 0; i < 4; i++) {
uint32_t mask = ~(0xFF << (i * 8));
if ((imm & mask) == mask) {
mvni(vd, ~bytes[i] & 0xFF, LSL, i * 8);
return;
}
}
// Immediate is of the form 0x00MMFFFF.
if ((imm & 0xFF00FFFF) == 0x0000FFFF) {
movi(vd, bytes[2], MSL, 16);
return;
}
// Immediate is of the form 0x0000MMFF.
if ((imm & 0xFFFF00FF) == 0x000000FF) {
movi(vd, bytes[1], MSL, 8);
return;
}
// Immediate is of the form 0xFFMM0000.
if ((imm & 0xFF00FFFF) == 0xFF000000) {
mvni(vd, ~bytes[2] & 0xFF, MSL, 16);
return;
}
// Immediate is of the form 0xFFFFMM00.
if ((imm & 0xFFFF00FF) == 0xFFFF0000) {
mvni(vd, ~bytes[1] & 0xFF, MSL, 8);
return;
}
// Top and bottom 16-bits are equal.
if (((imm >> 16) & 0xFFFF) == (imm & 0xFFFF)) {
Movi16bitHelper(vd.Is64Bits() ? vd.V4H() : vd.V8H(), imm & 0xFFFF);
return;
}
// Default case.
{
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireW();
Mov(temp, imm);
dup(vd, temp);
}
}
void TurboAssembler::Movi64bitHelper(const VRegister& vd, uint64_t imm) {
// All bytes are either 0x00 or 0xFF.
{
bool all0orff = true;
for (int i = 0; i < 8; ++i) {
int byteval = (imm >> (i * 8)) & 0xFF;
if (byteval != 0 && byteval != 0xFF) {
all0orff = false;
break;
}
}
if (all0orff == true) {
movi(vd, imm);
return;
}
}
// Top and bottom 32-bits are equal.
if (((imm >> 32) & 0xFFFFFFFF) == (imm & 0xFFFFFFFF)) {
Movi32bitHelper(vd.Is64Bits() ? vd.V2S() : vd.V4S(), imm & 0xFFFFFFFF);
return;
}
// Default case.
{
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Mov(temp, imm);
if (vd.Is1D()) {
mov(vd.D(), 0, temp);
} else {
dup(vd.V2D(), temp);
}
}
}
void TurboAssembler::Movi(const VRegister& vd, uint64_t imm, Shift shift,
int shift_amount) {
DCHECK(allow_macro_instructions());
if (shift_amount != 0 || shift != LSL) {
movi(vd, imm, shift, shift_amount);
} else if (vd.Is8B() || vd.Is16B()) {
// 8-bit immediate.
DCHECK(is_uint8(imm));
movi(vd, imm);
} else if (vd.Is4H() || vd.Is8H()) {
// 16-bit immediate.
Movi16bitHelper(vd, imm);
} else if (vd.Is2S() || vd.Is4S()) {
// 32-bit immediate.
Movi32bitHelper(vd, imm);
} else {
// 64-bit immediate.
Movi64bitHelper(vd, imm);
}
}
void TurboAssembler::Movi(const VRegister& vd, uint64_t hi, uint64_t lo) {
// TODO(all): Move 128-bit values in a more efficient way.
DCHECK(vd.Is128Bits());
UseScratchRegisterScope temps(this);
Movi(vd.V2D(), lo);
Register temp = temps.AcquireX();
Mov(temp, hi);
Ins(vd.V2D(), 1, temp);
}
void TurboAssembler::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 TurboAssembler::CountClearHalfWords(uint64_t imm, unsigned reg_size) {
DCHECK_EQ(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 TurboAssembler::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 TurboAssembler::IsImmMovn(uint64_t imm, unsigned reg_size) {
return IsImmMovz(~imm, reg_size);
}
void TurboAssembler::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 TurboAssembler::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 TurboAssembler::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 TurboAssembler::MoveImmediateForShiftedOp(const Register& dst,
int64_t imm,
PreShiftImmMode mode) {
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);
if (mode == kLimitShiftForSP) {
// When applied to the stack pointer, the subsequent arithmetic operation
// can use the extend form to shift left by a maximum of four bits. Right
// shifts are not allowed, so we filter them out later before the new
// immediate is tested.
shift_low = std::min(shift_low, 4);
}
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) | ((INT64_C(1) << shift_high) - 1);
if ((mode != kNoShift) && 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 ((mode == kAnyShift) && 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 TurboAssembler::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()) {
PreShiftImmMode mode = kAnyShift;
// If the destination or source register is the stack pointer, we can
// only pre-shift the immediate right by values supported in the add/sub
// extend encoding.
if (rd.Is(sp)) {
// If the destination is SP and flags will be set, we can't pre-shift
// the immediate at all.
mode = (S == SetFlags) ? kNoShift : kLimitShiftForSP;
} else if (rn.Is(sp)) {
mode = kLimitShiftForSP;
}
Operand imm_operand =
MoveImmediateForShiftedOp(temp, operand.ImmediateValue(), mode);
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 TurboAssembler::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_LE(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 TurboAssembler::LoadStoreMacro(const CPURegister& rt,
const MemOperand& addr, LoadStoreOp op) {
int64_t offset = addr.offset();
unsigned 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 TurboAssembler::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();
unsigned 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);
}
}
}
bool TurboAssembler::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 TurboAssembler::Adr(const Register& rd, Label* label, AdrHint hint) {
DCHECK(allow_macro_instructions());
DCHECK(!rd.IsZero());
if (hint == kAdrNear) {
adr(rd, label);
return;
}
DCHECK_EQ(hint, kAdrFar);
if (label->is_bound()) {
int label_offset = label->pos() - pc_offset();
if (Instruction::IsValidPCRelOffset(label_offset)) {
adr(rd, label);
} else {
DCHECK_LE(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 TurboAssembler::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 TurboAssembler::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 TurboAssembler::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 TurboAssembler::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 TurboAssembler::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 TurboAssembler::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 TurboAssembler::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 != nullptr) && (is_representable != nullptr)) {
B(is_not_representable, vs);
B(is_representable);
} else if (is_not_representable != nullptr) {
B(is_not_representable, vs);
} else if (is_representable != nullptr) {
B(is_representable, vc);
}
}
// Abstracted stack operations.
void TurboAssembler::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();
DCHECK_EQ(0, (size * count) % 16);
PushHelper(count, size, src0, src1, src2, src3);
}
void TurboAssembler::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();
DCHECK_EQ(0, (size * count) % 16);
PushHelper(4, size, src0, src1, src2, src3);
PushHelper(count - 4, size, src4, src5, src6, src7);
}
void TurboAssembler::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();
DCHECK_EQ(0, (size * count) % 16);
PopHelper(count, size, dst0, dst1, dst2, dst3);
}
void TurboAssembler::Pop(const CPURegister& dst0, const CPURegister& dst1,
const CPURegister& dst2, const CPURegister& dst3,
const CPURegister& dst4, const CPURegister& dst5,
const CPURegister& dst6, const CPURegister& dst7) {
// 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, dst4, dst5, dst6, dst7));
DCHECK(AreSameSizeAndType(dst0, dst1, dst2, dst3, dst4, dst5, dst6, dst7));
DCHECK(dst0.IsValid());
int count = 5 + dst5.IsValid() + dst6.IsValid() + dst7.IsValid();
int size = dst0.SizeInBytes();
DCHECK_EQ(0, (size * count) % 16);
PopHelper(4, size, dst0, dst1, dst2, dst3);
PopHelper(count - 4, size, dst4, dst5, dst6, dst7);
}
void TurboAssembler::Push(const Register& src0, const VRegister& src1) {
int size = src0.SizeInBytes() + src1.SizeInBytes();
DCHECK_EQ(0, size % 16);
// Reserve room for src0 and push src1.
str(src1, MemOperand(sp, -size, PreIndex));
// Fill the gap with src0.
str(src0, MemOperand(sp, src1.SizeInBytes()));
}
void TurboAssembler::PushCPURegList(CPURegList registers) {
int size = registers.RegisterSizeInBytes();
DCHECK_EQ(0, (size * registers.Count()) % 16);
// Push up to four registers at a time.
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 TurboAssembler::PopCPURegList(CPURegList registers) {
int size = registers.RegisterSizeInBytes();
DCHECK_EQ(0, (size * registers.Count()) % 16);
// Pop up to four registers at a time.
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);
}
}
void MacroAssembler::PushMultipleTimes(CPURegister src, Register count) {
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 TurboAssembler::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(sp, -1 * size, PreIndex));
break;
case 2:
DCHECK(src2.IsNone() && src3.IsNone());
stp(src1, src0, MemOperand(sp, -2 * size, PreIndex));
break;
case 3:
DCHECK(src3.IsNone());
stp(src2, src1, MemOperand(sp, -3 * size, PreIndex));
str(src0, MemOperand(sp, 2 * size));
break;
case 4:
// Skip over 4 * size, then fill in the gap. This allows four W registers
// to be pushed using sp, whilst maintaining 16-byte alignment for sp
// at all times.
stp(src3, src2, MemOperand(sp, -4 * size, PreIndex));
stp(src1, src0, MemOperand(sp, 2 * size));
break;
default:
UNREACHABLE();
}
}
void TurboAssembler::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(sp, 1 * size, PostIndex));
break;
case 2:
DCHECK(dst2.IsNone() && dst3.IsNone());
ldp(dst0, dst1, MemOperand(sp, 2 * size, PostIndex));
break;
case 3:
DCHECK(dst3.IsNone());
ldr(dst2, MemOperand(sp, 2 * size));
ldp(dst0, dst1, MemOperand(sp, 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 sp, whilst maintaining 16-byte alignment
// for sp at all times.
ldp(dst2, dst3, MemOperand(sp, 2 * size));
ldp(dst0, dst1, MemOperand(sp, 4 * size, PostIndex));
break;
default:
UNREACHABLE();
}
}
void TurboAssembler::Poke(const CPURegister& src, const Operand& offset) {
if (offset.IsImmediate()) {
DCHECK_GE(offset.ImmediateValue(), 0);
} else if (emit_debug_code()) {
Cmp(xzr, offset);
Check(le, AbortReason::kStackAccessBelowStackPointer);
}
Str(src, MemOperand(sp, offset));
}
void TurboAssembler::Peek(const CPURegister& dst, const Operand& offset) {
if (offset.IsImmediate()) {
DCHECK_GE(offset.ImmediateValue(), 0);
} else if (emit_debug_code()) {
Cmp(xzr, offset);
Check(le, AbortReason::kStackAccessBelowStackPointer);
}
Ldr(dst, MemOperand(sp, offset));
}
void TurboAssembler::PokePair(const CPURegister& src1, const CPURegister& src2,
int offset) {
DCHECK(AreSameSizeAndType(src1, src2));
DCHECK((offset >= 0) && ((offset % src1.SizeInBytes()) == 0));
Stp(src1, src2, MemOperand(sp, 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(sp, offset));
}
void MacroAssembler::PushCalleeSavedRegisters() {
// Ensure that the macro-assembler doesn't use any scratch registers.
InstructionAccurateScope scope(this);
MemOperand tos(sp, -2 * static_cast<int>(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);
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);
MemOperand tos(sp, 2 * kXRegSize, PostIndex);
ldp(x19, x20, tos);
ldp(x21, x22, tos);
ldp(x23, x24, tos);
ldp(x25, x26, tos);
ldp(x27, x28, tos);
ldp(x29, x30, tos);
ldp(d8, d9, tos);
ldp(d10, d11, tos);
ldp(d12, d13, tos);
ldp(d14, d15, tos);
}
void TurboAssembler::AssertSpAligned() {
if (emit_debug_code()) {
HardAbortScope hard_abort(this); // Avoid calls to Abort.
// Arm64 requires the stack pointer to be 16-byte aligned prior to address
// calculation.
UseScratchRegisterScope scope(this);
Register temp = scope.AcquireX();
Mov(temp, sp);
Tst(temp, 15);
Check(eq, AbortReason::kUnexpectedStackPointer);
}
}
void TurboAssembler::CopySlots(int dst, Register src, Register slot_count) {
DCHECK(!src.IsZero());
UseScratchRegisterScope scope(this);
Register dst_reg = scope.AcquireX();
SlotAddress(dst_reg, dst);
SlotAddress(src, src);
CopyDoubleWords(dst_reg, src, slot_count);
}
void TurboAssembler::CopySlots(Register dst, Register src,
Register slot_count) {
DCHECK(!dst.IsZero() && !src.IsZero());
SlotAddress(dst, dst);
SlotAddress(src, src);
CopyDoubleWords(dst, src, slot_count);
}
void TurboAssembler::CopyDoubleWords(Register dst, Register src, Register count,
CopyDoubleWordsMode mode) {
DCHECK(!AreAliased(dst, src, count));
if (emit_debug_code()) {
Register pointer1 = dst;
Register pointer2 = src;
if (mode == kSrcLessThanDst) {
pointer1 = src;
pointer2 = dst;
}
// Copy requires pointer1 < pointer2 || (pointer1 - pointer2) >= count.
Label pointer1_below_pointer2;
Subs(pointer1, pointer1, pointer2);
B(lt, &pointer1_below_pointer2);
Cmp(pointer1, count);
Check(ge, AbortReason::kOffsetOutOfRange);
Bind(&pointer1_below_pointer2);
Add(pointer1, pointer1, pointer2);
}
static_assert(kSystemPointerSize == kDRegSize,
"pointers must be the same size as doubles");
int direction = (mode == kDstLessThanSrc) ? 1 : -1;
UseScratchRegisterScope scope(this);
VRegister temp0 = scope.AcquireD();
VRegister temp1 = scope.AcquireD();
Label pairs, loop, done;
Tbz(count, 0, &pairs);
Ldr(temp0, MemOperand(src, direction * kSystemPointerSize, PostIndex));
Sub(count, count, 1);
Str(temp0, MemOperand(dst, direction * kSystemPointerSize, PostIndex));
Bind(&pairs);
if (mode == kSrcLessThanDst) {
// Adjust pointers for post-index ldp/stp with negative offset:
Sub(dst, dst, kSystemPointerSize);
Sub(src, src, kSystemPointerSize);
}
Bind(&loop);
Cbz(count, &done);
Ldp(temp0, temp1,
MemOperand(src, 2 * direction * kSystemPointerSize, PostIndex));
Sub(count, count, 2);
Stp(temp0, temp1,
MemOperand(dst, 2 * direction * kSystemPointerSize, PostIndex));
B(&loop);
// TODO(all): large copies may benefit from using temporary Q registers
// to copy four double words per iteration.
Bind(&done);
}
void TurboAssembler::SlotAddress(Register dst, int slot_offset) {
Add(dst, sp, slot_offset << kSystemPointerSizeLog2);
}
void TurboAssembler::SlotAddress(Register dst, Register slot_offset) {
Add(dst, sp, Operand(slot_offset, LSL, kSystemPointerSizeLog2));
}
void TurboAssembler::AssertFPCRState(Register fpcr) {
if (emit_debug_code()) {
Label unexpected_mode, done;
UseScratchRegisterScope temps(this);
if (fpcr.IsNone()) {
fpcr = temps.AcquireX();
Mrs(fpcr, FPCR);
}
// 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(AbortReason::kUnexpectedFPCRMode);
Bind(&done);
}
}
void TurboAssembler::CanonicalizeNaN(const VRegister& dst,
const VRegister& src) {
AssertFPCRState();
// Subtracting 0.0 preserves all inputs except for signalling NaNs, which
// become quiet NaNs. We use fsub rather than fadd because fsub preserves -0.0
// inputs: -0.0 + 0.0 = 0.0, but -0.0 - 0.0 = -0.0.
Fsub(dst, src, fp_zero);
}
void TurboAssembler::LoadRoot(Register destination, RootIndex 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(kRootRegister, RootRegisterOffsetForRootIndex(index)));
}
void MacroAssembler::LoadObject(Register result, Handle<Object> object) {
AllowDeferredHandleDereference heap_object_check;
if (object->IsHeapObject()) {
Mov(result, Handle<HeapObject>::cast(object));
} else {
Mov(result, Operand(Smi::cast(*object)));
}
}
void TurboAssembler::Move(Register dst, Smi src) { Mov(dst, src); }
void TurboAssembler::MovePair(Register dst0, Register src0, Register dst1,
Register src1) {
DCHECK_NE(dst0, dst1);
if (dst0 != src1) {
Mov(dst0, src0);
Mov(dst1, src1);
} else if (dst1 != src0) {
// Swap the order of the moves to resolve the overlap.
Mov(dst1, src1);
Mov(dst0, src0);
} else {
// Worse case scenario, this is a swap.
Swap(dst0, src0);
}
}
void TurboAssembler::Swap(Register lhs, Register rhs) {
DCHECK(lhs.IsSameSizeAndType(rhs));
DCHECK(!lhs.Is(rhs));
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Mov(temp, rhs);
Mov(rhs, lhs);
Mov(lhs, temp);
}
void TurboAssembler::Swap(VRegister lhs, VRegister rhs) {
DCHECK(lhs.IsSameSizeAndType(rhs));
DCHECK(!lhs.Is(rhs));
UseScratchRegisterScope temps(this);
VRegister temp = VRegister::no_reg();
if (lhs.IsS()) {
temp = temps.AcquireS();
} else if (lhs.IsD()) {
temp = temps.AcquireD();
} else {
DCHECK(lhs.IsQ());
temp = temps.AcquireQ();
}
Mov(temp, rhs);
Mov(rhs, lhs);
Mov(lhs, temp);
}
void TurboAssembler::AssertSmi(Register object, AbortReason reason) {
if (emit_debug_code()) {
STATIC_ASSERT(kSmiTag == 0);
Tst(object, kSmiTagMask);
Check(eq, reason);
}
}
void MacroAssembler::AssertNotSmi(Register object, AbortReason reason) {
if (emit_debug_code()) {
STATIC_ASSERT(kSmiTag == 0);
Tst(object, kSmiTagMask);
Check(ne, reason);
}
}
void MacroAssembler::AssertConstructor(Register object) {
if (emit_debug_code()) {
AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotAConstructor);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
LoadTaggedPointerField(temp,
FieldMemOperand(object, HeapObject::kMapOffset));
Ldrb(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
Tst(temp, Operand(Map::IsConstructorBit::kMask));
Check(ne, AbortReason::kOperandIsNotAConstructor);
}
}
void MacroAssembler::AssertFunction(Register object) {
if (emit_debug_code()) {
AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotAFunction);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
CompareObjectType(object, temp, temp, JS_FUNCTION_TYPE);
Check(eq, AbortReason::kOperandIsNotAFunction);
}
}
void MacroAssembler::AssertBoundFunction(Register object) {
if (emit_debug_code()) {
AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotABoundFunction);
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
CompareObjectType(object, temp, temp, JS_BOUND_FUNCTION_TYPE);
Check(eq, AbortReason::kOperandIsNotABoundFunction);
}
}
void MacroAssembler::AssertGeneratorObject(Register object) {
if (!emit_debug_code()) return;
AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotAGeneratorObject);
// Load map
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
LoadTaggedPointerField(temp, FieldMemOperand(object, HeapObject::kMapOffset));
Label do_check;
// Load instance type and check if JSGeneratorObject
CompareInstanceType(temp, temp, JS_GENERATOR_OBJECT_TYPE);
B(eq, &do_check);
// Check if JSAsyncFunctionObject
Cmp(temp, JS_ASYNC_FUNCTION_OBJECT_TYPE);
B(eq, &do_check);
// Check if JSAsyncGeneratorObject
Cmp(temp, JS_ASYNC_GENERATOR_OBJECT_TYPE);
bind(&do_check);
// Restore generator object to register and perform assertion
Check(eq, AbortReason::kOperandIsNotAGeneratorObject);
}
void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
Label done_checking;
AssertNotSmi(object);
JumpIfRoot(object, RootIndex::kUndefinedValue, &done_checking);
LoadTaggedPointerField(scratch,
FieldMemOperand(object, HeapObject::kMapOffset));
CompareInstanceType(scratch, scratch, ALLOCATION_SITE_TYPE);
Assert(eq, AbortReason::kExpectedUndefinedOrCell);
Bind(&done_checking);
}
}
void TurboAssembler::AssertPositiveOrZero(Register value) {
if (emit_debug_code()) {
Label done;
int sign_bit = value.Is64Bits() ? kXSignBit : kWSignBit;
Tbz(value, sign_bit, &done);
Abort(AbortReason::kUnexpectedNegativeValue);
Bind(&done);
}
}
void TurboAssembler::CallRuntimeWithCEntry(Runtime::FunctionId fid,
Register centry) {
const Runtime::Function* f = Runtime::FunctionForId(fid);
// 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, f->nargs);
Mov(x1, ExternalReference::Create(f));
DCHECK(!AreAliased(centry, x0, x1));
CallCodeObject(centry);
}
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::Create(f));
Handle<Code> code =
CodeFactory::CEntry(isolate(), f->result_size, save_doubles);
Call(code, RelocInfo::CODE_TARGET);
}
void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
bool builtin_exit_frame) {
Mov(x1, builtin);
Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
kArgvOnStack, builtin_exit_frame);
Jump(code, RelocInfo::CODE_TARGET);
}
void MacroAssembler::JumpToInstructionStream(Address entry) {
Ldr(kOffHeapTrampolineRegister, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
Br(kOffHeapTrampolineRegister);
}
void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
const Runtime::Function* function = Runtime::FunctionForId(fid);
DCHECK_EQ(1, function->result_size);
if (function->nargs >= 0) {
// 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, function->nargs);
}
JumpToExternalReference(ExternalReference::Create(fid));
}
int TurboAssembler::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 TurboAssembler::CallCFunction(ExternalReference function,
int num_of_reg_args) {
CallCFunction(function, num_of_reg_args, 0);
}
void TurboAssembler::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);
}
static const int kRegisterPassedArguments = 8;
void TurboAssembler::CallCFunction(Register function, int num_of_reg_args,
int num_of_double_args) {
DCHECK_LE(num_of_reg_args + num_of_double_args, kMaxCParameters);
DCHECK(has_frame());
// 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_LE(num_of_reg_args, 1);
DCHECK_LE(num_of_double_args + num_of_reg_args, 2);
}
// Save the frame pointer and PC so that the stack layout remains iterable,
// even without an ExitFrame which normally exists between JS and C frames.
if (isolate() != nullptr) {
Register scratch1 = x4;
Register scratch2 = x5;
Push(scratch1, scratch2);
Label get_pc;
Bind(&get_pc);
Adr(scratch2, &get_pc);
Mov(scratch1, ExternalReference::fast_c_call_caller_pc_address(isolate()));
Str(scratch2, MemOperand(scratch1));
Mov(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
Str(fp, MemOperand(scratch1));
Pop(scratch2, scratch1);
}
// 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 (isolate() != nullptr) {
// We don't unset the PC; the FP is the source of truth.
Register scratch = x4;
Push(scratch, xzr);
Mov(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
Str(xzr, MemOperand(scratch));
Pop(xzr, scratch);
}
if (num_of_reg_args > kRegisterPassedArguments) {
// Drop the register passed arguments.
int claim_slots = RoundUp(num_of_reg_args - kRegisterPassedArguments, 2);
Drop(claim_slots);
}
}
void TurboAssembler::LoadFromConstantsTable(Register destination,
int constant_index) {
DCHECK(RootsTable::IsImmortalImmovable(RootIndex::kBuiltinsConstantsTable));
LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
LoadTaggedPointerField(
destination, FieldMemOperand(destination, FixedArray::OffsetOfElementAt(
constant_index)));
}
void TurboAssembler::LoadRootRelative(Register destination, int32_t offset) {
Ldr(destination, MemOperand(kRootRegister, offset));
}
void TurboAssembler::LoadRootRegisterOffset(Register destination,
intptr_t offset) {
if (offset == 0) {
Mov(destination, kRootRegister);
} else {
Add(destination, kRootRegister, offset);
}
}
void TurboAssembler::Jump(Register target, Condition cond) {
if (cond == nv) return;
Label done;
if (cond != al) B(NegateCondition(cond), &done);
Br(target);
Bind(&done);
}
void TurboAssembler::JumpHelper(int64_t offset, RelocInfo::Mode rmode,
Condition cond) {
if (cond == nv) return;
Label done;
if (cond != al) B(NegateCondition(cond), &done);
if (CanUseNearCallOrJump(rmode)) {
DCHECK(IsNearCallOffset(offset));
near_jump(static_cast<int>(offset), rmode);
} else {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
uint64_t imm = reinterpret_cast<uint64_t>(pc_) + offset * kInstrSize;
Mov(temp, Immediate(imm, rmode));
Br(temp);
}
Bind(&done);
}
namespace {
// The calculated offset is either:
// * the 'target' input unmodified if this is a WASM call, or
// * the offset of the target from the current PC, in instructions, for any
// other type of call.
static int64_t CalculateTargetOffset(Address target, RelocInfo::Mode rmode,
byte* pc) {
int64_t offset = static_cast<int64_t>(target);
// The target of WebAssembly calls is still an index instead of an actual
// address at this point, and needs to be encoded as-is.
if (rmode != RelocInfo::WASM_CALL && rmode != RelocInfo::WASM_STUB_CALL) {
offset -= reinterpret_cast<int64_t>(pc);
DCHECK_EQ(offset % kInstrSize, 0);
offset = offset / static_cast<int>(kInstrSize);
}
return offset;
}
} // namespace
void TurboAssembler::Jump(Address target, RelocInfo::Mode rmode,
Condition cond) {
JumpHelper(CalculateTargetOffset(target, rmode, pc_), rmode, cond);
}
void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
Condition cond) {
DCHECK(RelocInfo::IsCodeTarget(rmode));
DCHECK_IMPLIES(options().isolate_independent_code,
Builtins::IsIsolateIndependentBuiltin(*code));
if (options().inline_offheap_trampolines) {
int builtin_index = Builtins::kNoBuiltinId;
if (isolate()->builtins()->IsBuiltinHandle(code, &builtin_index) &&
Builtins::IsIsolateIndependent(builtin_index)) {
// Inline the trampoline.
RecordCommentForOffHeapTrampoline(builtin_index);
CHECK_NE(builtin_index, Builtins::kNoBuiltinId);
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
EmbeddedData d = EmbeddedData::FromBlob();
Address entry = d.InstructionStartOfBuiltin(builtin_index);
Ldr(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
Jump(scratch, cond);
return;
}
}
if (CanUseNearCallOrJump(rmode)) {
EmbeddedObjectIndex index = AddEmbeddedObject(code);
DCHECK(is_int32(index));
JumpHelper(static_cast<int64_t>(index), rmode, cond);
} else {
Jump(code.address(), rmode, cond);
}
}
void TurboAssembler::Call(Register target) {
BlockPoolsScope scope(this);
Blr(target);
}
void TurboAssembler::Call(Address target, RelocInfo::Mode rmode) {
BlockPoolsScope scope(this);
if (CanUseNearCallOrJump(rmode)) {
int64_t offset = CalculateTargetOffset(target, rmode, pc_);
DCHECK(IsNearCallOffset(offset));
near_call(static_cast<int>(offset), rmode);
} else {
IndirectCall(target, rmode);
}
}
void TurboAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode) {
DCHECK_IMPLIES(options().isolate_independent_code,
Builtins::IsIsolateIndependentBuiltin(*code));
BlockPoolsScope scope(this);
if (options().inline_offheap_trampolines) {
int builtin_index = Builtins::kNoBuiltinId;
if (isolate()->builtins()->IsBuiltinHandle(code, &builtin_index) &&
Builtins::IsIsolateIndependent(builtin_index)) {
// Inline the trampoline.
RecordCommentForOffHeapTrampoline(builtin_index);
CHECK_NE(builtin_index, Builtins::kNoBuiltinId);
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
EmbeddedData d = EmbeddedData::FromBlob();
Address entry = d.InstructionStartOfBuiltin(builtin_index);
Ldr(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
Call(scratch);
return;
}
}
if (CanUseNearCallOrJump(rmode)) {
EmbeddedObjectIndex index = AddEmbeddedObject(code);
DCHECK(is_int32(index));
near_call(static_cast<int32_t>(index), rmode);
} else {
IndirectCall(code.address(), rmode);
}
}
void TurboAssembler::Call(ExternalReference target) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Mov(temp, target);
Call(temp);
}
void TurboAssembler::LoadEntryFromBuiltinIndex(Register builtin_index) {
STATIC_ASSERT(kSystemPointerSize == 8);
STATIC_ASSERT(kSmiTagSize == 1);
STATIC_ASSERT(kSmiTag == 0);
// The builtin_index register contains the builtin index as a Smi.
// Untagging is folded into the indexing operand below.
#if defined(V8_COMPRESS_POINTERS) || defined(V8_31BIT_SMIS_ON_64BIT_ARCH)
STATIC_ASSERT(kSmiShiftSize == 0);
Lsl(builtin_index, builtin_index, kSystemPointerSizeLog2 - kSmiShift);
#else
STATIC_ASSERT(kSmiShiftSize == 31);
Asr(builtin_index, builtin_index, kSmiShift - kSystemPointerSizeLog2);
#endif
Add(builtin_index, builtin_index, IsolateData::builtin_entry_table_offset());
Ldr(builtin_index, MemOperand(kRootRegister, builtin_index));
}
void TurboAssembler::CallBuiltinByIndex(Register builtin_index) {
LoadEntryFromBuiltinIndex(builtin_index);
Call(builtin_index);
}
void TurboAssembler::LoadCodeObjectEntry(Register destination,
Register code_object) {
// Code objects are called differently depending on whether we are generating
// builtin code (which will later be embedded into the binary) or compiling
// user JS code at runtime.
// * Builtin code runs in --jitless mode and thus must not call into on-heap
// Code targets. Instead, we dispatch through the builtins entry table.
// * Codegen at runtime does not have this restriction and we can use the
// shorter, branchless instruction sequence. The assumption here is that
// targets are usually generated code and not builtin Code objects.
if (options().isolate_independent_code) {
DCHECK(root_array_available());
Label if_code_is_off_heap, out;
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
DCHECK(!AreAliased(destination, scratch));
DCHECK(!AreAliased(code_object, scratch));
// Check whether the Code object is an off-heap trampoline. If so, call its
// (off-heap) entry point directly without going through the (on-heap)
// trampoline. Otherwise, just call the Code object as always.
Ldrsw(scratch, FieldMemOperand(code_object, Code::kFlagsOffset));
Tst(scratch, Operand(Code::IsOffHeapTrampoline::kMask));
B(ne, &if_code_is_off_heap);
// Not an off-heap trampoline object, the entry point is at
// Code::raw_instruction_start().
Add(destination, code_object, Code::kHeaderSize - kHeapObjectTag);
B(&out);
// An off-heap trampoline, the entry point is loaded from the builtin entry
// table.
bind(&if_code_is_off_heap);
Ldrsw(scratch, FieldMemOperand(code_object, Code::kBuiltinIndexOffset));
Lsl(destination, scratch, kSystemPointerSizeLog2);
Add(destination, destination, kRootRegister);
Ldr(destination,
MemOperand(destination, IsolateData::builtin_entry_table_offset()));
bind(&out);
} else {
Add(destination, code_object, Code::kHeaderSize - kHeapObjectTag);
}
}
void TurboAssembler::CallCodeObject(Register code_object) {
LoadCodeObjectEntry(code_object, code_object);
Call(code_object);
}
void TurboAssembler::JumpCodeObject(Register code_object) {
LoadCodeObjectEntry(code_object, code_object);
Jump(code_object);
}
void TurboAssembler::StoreReturnAddressAndCall(Register target) {
// This generates the final instruction sequence for calls to C functions
// once an exit frame has been constructed.
//
// Note that this assumes the caller code (i.e. the Code object currently
// being generated) is immovable or that the callee function cannot trigger
// GC, since the callee function will return to it.
UseScratchRegisterScope temps(this);
Register scratch1 = temps.AcquireX();
Label return_location;
Adr(scratch1, &return_location);
Poke(scratch1, 0);
if (emit_debug_code()) {
// Verify that the slot below fp[kSPOffset]-8 points to the return location.
Register scratch2 = temps.AcquireX();
Ldr(scratch2, MemOperand(fp, ExitFrameConstants::kSPOffset));
Ldr(scratch2, MemOperand(scratch2, -static_cast<int64_t>(kXRegSize)));
Cmp(scratch2, scratch1);
Check(eq, AbortReason::kReturnAddressNotFoundInFrame);
}
Blr(target);
Bind(&return_location);
}
void TurboAssembler::IndirectCall(Address target, RelocInfo::Mode rmode) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Mov(temp, Immediate(target, rmode));
Blr(temp);
}
bool TurboAssembler::IsNearCallOffset(int64_t offset) {
return is_int26(offset);
}
void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
BlockPoolsScope scope(this);
NoRootArrayScope no_root_array(this);
#ifdef DEBUG
Label start;
Bind(&start);
#endif
// Make sure that the deopt id can be encoded in 16 bits, so can be encoded
// in a single movz instruction with a zero shift.
DCHECK(is_uint16(deopt_id));
movz(x26, deopt_id);
int64_t offset = static_cast<int64_t>(target) -
static_cast<int64_t>(options().code_range_start);
DCHECK_EQ(offset % kInstrSize, 0);
offset = offset / static_cast<int>(kInstrSize);
DCHECK(IsNearCallOffset(offset));
near_call(static_cast<int>(offset), RelocInfo::RUNTIME_ENTRY);
}
void TurboAssembler::PrepareForTailCall(const ParameterCount& callee_args_count,
Register caller_args_count_reg,
Register scratch0, Register scratch1) {
#if DEBUG
if (callee_args_count.is_reg()) {
DCHECK(!AreAliased(callee_args_count.reg(), caller_args_count_reg, scratch0,
scratch1));
} else {
DCHECK(!AreAliased(caller_args_count_reg, scratch0, scratch1));
}
#endif
// Calculate the end of destination area where we will put the arguments
// after we drop current frame. We add kSystemPointerSize to count the
// receiver argument which is not included into formal parameters count.
Register dst_reg = scratch0;
Add(dst_reg, fp, Operand(caller_args_count_reg, LSL, kSystemPointerSizeLog2));
Add(dst_reg, dst_reg,
StandardFrameConstants::kCallerSPOffset + kSystemPointerSize);
// Round dst_reg up to a multiple of 16 bytes, so that we overwrite any
// potential padding.
Add(dst_reg, dst_reg, 15);
Bic(dst_reg, dst_reg, 15);
Register src_reg = caller_args_count_reg;
// Calculate the end of source area. +kSystemPointerSize is for the receiver.
if (callee_args_count.is_reg()) {
Add(src_reg, sp,
Operand(callee_args_count.reg(), LSL, kSystemPointerSizeLog2));
Add(src_reg, src_reg, kSystemPointerSize);
} else {
Add(src_reg, sp, (callee_args_count.immediate() + 1) * kSystemPointerSize);
}
// Round src_reg up to a multiple of 16 bytes, so we include any potential
// padding in the copy.
Add(src_reg, src_reg, 15);
Bic(src_reg, src_reg, 15);
if (FLAG_debug_code) {
Cmp(src_reg, dst_reg);
Check(lo, AbortReason::kStackAccessBelowStackPointer);
}
// Restore caller's frame pointer and return address now as they will be
// overwritten by the copying loop.
Ldr(lr, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
Ldr(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
// Now copy callee arguments to the caller frame going backwards to avoid
// callee arguments corruption (source and destination areas could overlap).
// Both src_reg and dst_reg are pointing to the word after the one to copy,
// so they must be pre-decremented in the loop.
Register tmp_reg = scratch1;
Label loop, entry;
B(&entry);
bind(&loop);
Ldr(tmp_reg, MemOperand(src_reg, -kSystemPointerSize, PreIndex));
Str(tmp_reg, MemOperand(dst_reg, -kSystemPointerSize, PreIndex));
bind(&entry);
Cmp(sp, src_reg);
B(ne, &loop);
// Leave current frame.
Mov(sp, dst_reg);
}
void MacroAssembler::InvokePrologue(const ParameterCount& expected,
const ParameterCount& actual, Label* done,
InvokeFlag flag,
bool* definitely_mismatches) {
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));
if (expected.is_immediate()) {
DCHECK(actual.is_immediate());
Mov(x0, actual.immediate());
if (expected.immediate() == actual.immediate()) {
definitely_matches = true;
} else {
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());
Mov(x0, actual_op);
// If actual == expected perform a regular invocation.
Cmp(expected.reg(), actual_op);
B(eq, &regular_invoke);
}
// If the argument counts may mismatch, generate a call to the argument
// adaptor.
if (!definitely_matches) {
Handle<Code> adaptor = BUILTIN_CODE(isolate(), ArgumentsAdaptorTrampoline);
if (flag == CALL_FUNCTION) {
Call(adaptor);
if (!*definitely_mismatches) {
// If the arg counts don't match, no extra code is emitted by
// MAsm::InvokeFunctionCode and we can just fall through.
B(done);
}
} else {
Jump(adaptor, RelocInfo::CODE_TARGET);
}
}
Bind(&regular_invoke);
}
void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
const ParameterCount& expected,
const ParameterCount& actual) {
Label skip_hook;
Mov(x4, ExternalReference::debug_hook_on_function_call_address(isolate()));
Ldrsb(x4, MemOperand(x4));
Cbz(x4, &skip_hook);
{
// Load receiver to pass it later to DebugOnFunctionCall hook.
Operand actual_op = actual.is_immediate() ? Operand(actual.immediate())
: Operand(actual.reg());
Mov(x4, actual_op);
Ldr(x4, MemOperand(sp, x4, LSL, kSystemPointerSizeLog2));
FrameScope frame(this,
has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
Register expected_reg = padreg;
Register actual_reg = padreg;
if (expected.is_reg()) expected_reg = expected.reg();
if (actual.is_reg()) actual_reg = actual.reg();
if (!new_target.is_valid()) new_target = padreg;
// Save values on stack.
SmiTag(expected_reg);
SmiTag(actual_reg);
Push(expected_reg, actual_reg, new_target, fun);
Push(fun, x4);
CallRuntime(Runtime::kDebugOnFunctionCall);
// Restore values from stack.
Pop(fun, new_target, actual_reg, expected_reg);
SmiUntag(actual_reg);
SmiUntag(expected_reg);
}
Bind(&skip_hook);
}
void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag) {
// You can't call a function without a valid frame.
DCHECK(flag == JUMP_FUNCTION || has_frame());
DCHECK(function.is(x1));
DCHECK_IMPLIES(new_target.is_valid(), new_target.is(x3));
// On function call, call into the debugger if necessary.
CheckDebugHook(function, new_target, expected, actual);
// Clear the new.target register if not given.
if (!new_target.is_valid()) {
LoadRoot(x3, RootIndex::kUndefinedValue);
}
Label done;
bool definitely_mismatches = false;
InvokePrologue(expected, actual, &done, flag, &definitely_mismatches);
// 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) {
// We call indirectly through the code field in the function to
// allow recompilation to take effect without changing any of the
// call sites.
Register code = kJavaScriptCallCodeStartRegister;
LoadTaggedPointerField(code,
FieldMemOperand(function, JSFunction::kCodeOffset));
if (flag == CALL_FUNCTION) {
CallCodeObject(code);
} else {
DCHECK(flag == JUMP_FUNCTION);
JumpCodeObject(code);
}
}
// Continue here if InvokePrologue does handle the invocation due to
// mismatched parameter counts.
Bind(&done);
}
void MacroAssembler::InvokeFunction(Register function, Register new_target,
const ParameterCount& actual,
InvokeFlag flag) {
// 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;
LoadTaggedPointerField(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.
LoadTaggedPointerField(
expected_reg,
FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
Ldrh(expected_reg,
FieldMemOperand(expected_reg,
SharedFunctionInfo::kFormalParameterCountOffset));
ParameterCount expected(expected_reg);
InvokeFunctionCode(function, new_target, expected, actual, flag);
}
void MacroAssembler::InvokeFunction(Register function,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag) {
// 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));
// Set up the context.
LoadTaggedPointerField(cp,
FieldMemOperand(function, JSFunction::kContextOffset));
InvokeFunctionCode(function, no_reg, expected, actual, flag);
}
void TurboAssembler::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 occurred, 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 TurboAssembler::TruncateDoubleToI(Isolate* isolate, Zone* zone,
Register result,
DoubleRegister double_input,
StubCallMode stub_mode) {
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);
// If we fell through then inline version didn't succeed - call stub instead.
Push(lr, double_input);
// DoubleToI preserves any registers it needs to clobber.
if (stub_mode == StubCallMode::kCallWasmRuntimeStub) {
Call(wasm::WasmCode::kDoubleToI, RelocInfo::WASM_STUB_CALL);
} else {
Call(BUILTIN_CODE(isolate, DoubleToI), RelocInfo::CODE_TARGET);
}
Ldr(result, MemOperand(sp, 0));
DCHECK_EQ(xzr.SizeInBytes(), double_input.SizeInBytes());
Pop(xzr, lr); // xzr to drop the double input on the stack.
Bind(&done);
// Keep our invariant that the upper 32 bits are zero.
Uxtw(result.W(), result.W());
}
void TurboAssembler::Prologue() {
Push(lr, fp, cp, x1);
Add(fp, sp, StandardFrameConstants::kFixedFrameSizeFromFp);
}
void TurboAssembler::EnterFrame(StackFrame::Type type) {
UseScratchRegisterScope temps(this);
if (type == StackFrame::INTERNAL) {
Register type_reg = temps.AcquireX();
Mov(type_reg, StackFrame::TypeToMarker(type));
// type_reg pushed twice for alignment.
Push(lr, fp, type_reg, type_reg);
const int kFrameSize =
TypedFrameConstants::kFixedFrameSizeFromFp + kSystemPointerSize;
Add(fp, sp, kFrameSize);
// sp[3] : lr
// sp[2] : fp
// sp[1] : type
// sp[0] : for alignment
} else if (type == StackFrame::WASM_COMPILED ||
type == StackFrame::WASM_COMPILE_LAZY ||
type == StackFrame::WASM_EXIT) {
Register type_reg = temps.AcquireX();
Mov(type_reg, StackFrame::TypeToMarker(type));
Push(lr, fp);
Mov(fp, sp);
Push(type_reg, padreg);
// sp[3] : lr
// sp[2] : fp
// sp[1] : type
// sp[0] : for alignment
} else {
DCHECK_EQ(type, StackFrame::CONSTRUCT);
Register type_reg = temps.AcquireX();
Mov(type_reg, StackFrame::TypeToMarker(type));
// Users of this frame type push a context pointer after the type field,
// so do it here to keep the stack pointer aligned.
Push(lr, fp, type_reg, cp);
// The context pointer isn't part of the fixed frame, so add an extra slot
// to account for it.
Add(fp, sp,
TypedFrameConstants::kFixedFrameSizeFromFp + kSystemPointerSize);
// sp[3] : lr
// sp[2] : fp
// sp[1] : type
// sp[0] : cp
}
}
void TurboAssembler::LeaveFrame(StackFrame::Type type) {
// Drop the execution stack down to the frame pointer and restore
// the caller frame pointer and return address.
Mov(sp, fp);
Pop(fp, lr);
}
void MacroAssembler::ExitFramePreserveFPRegs() {
DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
PushCPURegList(kCallerSavedV);
}
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 = kCallerSavedV;
DCHECK_EQ(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,
StackFrame::Type frame_type) {
DCHECK(frame_type == StackFrame::EXIT ||
frame_type == StackFrame::BUILTIN_EXIT);
// Set up the new stack frame.
Push(lr, fp);
Mov(fp, sp);
Mov(scratch, StackFrame::TypeToMarker(frame_type));
Push(scratch, xzr);
// fp[8]: CallerPC (lr)
// fp -> fp[0]: CallerFP (old fp)
// fp[-8]: STUB marker
// sp -> fp[-16]: Space reserved for SPOffset.
STATIC_ASSERT((2 * kSystemPointerSize) ==
ExitFrameConstants::kCallerSPOffset);
STATIC_ASSERT((1 * kSystemPointerSize) ==
ExitFrameConstants::kCallerPCOffset);
STATIC_ASSERT((0 * kSystemPointerSize) ==
ExitFrameConstants::kCallerFPOffset);
STATIC_ASSERT((-2 * kSystemPointerSize) == ExitFrameConstants::kSPOffset);
// Save the frame pointer and context pointer in the top frame.
Mov(scratch,
ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate()));
Str(fp, MemOperand(scratch));
Mov(scratch,
ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
Str(cp, MemOperand(scratch));
STATIC_ASSERT((-2 * kSystemPointerSize) ==
ExitFrameConstants::kLastExitFrameField);
if (save_doubles) {
ExitFramePreserveFPRegs();
}
// Round the number of space we need to claim to a multiple of two.
int slots_to_claim = RoundUp(extra_space + 1, 2);
// 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(slots_to_claim, kXRegSize);
// fp[8]: CallerPC (lr)
// fp -> fp[0]: CallerFP (old fp)
// fp[-8]: STUB marker
// fp[-16]: Space reserved for SPOffset.
// fp[-16 - fp_size]: Saved doubles (if save_doubles is true).
// sp[8]: Extra space reserved for caller (if extra_space != 0).
// sp -> sp[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, sp, kXRegSize);
Str(scratch, MemOperand(fp, ExitFrameConstants::kSPOffset));
}
// Leave the current exit frame.
void MacroAssembler::LeaveExitFrame(bool restore_doubles,
const Register& scratch,
const Register& scratch2) {
if (restore_doubles) {
ExitFrameRestoreFPRegs();
}
// Restore the context pointer from the top frame.
Mov(scratch,
ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
Ldr(cp, MemOperand(scratch));
if (emit_debug_code()) {
// Also emit debug code to clear the cp in the top frame.
Mov(scratch2, Operand(Context::kInvalidContext));
Mov(scratch, ExternalReference::Create(IsolateAddressId::kContextAddress,
isolate()));
Str(scratch2, MemOperand(scratch));
}
// Clear the frame pointer from the top frame.
Mov(scratch,
ExternalReference::Create(IsolateAddressId::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(sp, fp);
Pop(fp, lr);
}
void MacroAssembler::LoadGlobalProxy(Register dst) {
LoadNativeContextSlot(Context::GLOBAL_PROXY_INDEX, dst);
}
void MacroAssembler::LoadWeakValue(Register out, Register in,
Label* target_if_cleared) {
CompareAndBranch(in.W(), Operand(kClearedWeakHeapObjectLower32), eq,
target_if_cleared);
and_(out, in, Operand(~kWeakHeapObjectMask));
}
void MacroAssembler::IncrementCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
DCHECK_NE(value, 0);
if (FLAG_native_code_counters && counter->Enabled()) {
// This operation has to be exactly 32-bit wide in case the external
// reference table redirects the counter to a uint32_t dummy_stats_counter_
// field.
Mov(scratch2, ExternalReference::Create(counter));
Ldr(scratch1.W(), MemOperand(scratch2));
Add(scratch1.W(), scratch1.W(), value);
Str(scratch1.W(), MemOperand(scratch2));
}
}
void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
IncrementCounter(counter, -value, scratch1, scratch2);
}
void MacroAssembler::MaybeDropFrames() {
// Check whether we need to drop frames to restart a function on the stack.
Mov(x1, ExternalReference::debug_restart_fp_address(isolate()));
Ldr(x1, MemOperand(x1));
Tst(x1, x1);
Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
ne);
}
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);
}
// Sets condition flags based on comparison, and returns type in type_reg.
void MacroAssembler::CompareObjectType(Register object, Register map,
Register type_reg, InstanceType type) {
LoadTaggedPointerField(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) {
Ldrh(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
Cmp(type_reg, type);
}
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::CompareRoot(const Register& obj, RootIndex index) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
DCHECK(!AreAliased(obj, temp));
LoadRoot(temp, index);
Cmp(obj, temp);
}
void MacroAssembler::JumpIfRoot(const Register& obj, RootIndex index,
Label* if_equal) {
CompareRoot(obj, index);
B(eq, if_equal);
}
void MacroAssembler::JumpIfNotRoot(const Register& obj, RootIndex index,
Label* if_not_equal) {
CompareRoot(obj, index);
B(ne, if_not_equal);
}
void MacroAssembler::JumpIfIsInRange(const Register& value,
unsigned lower_limit,
unsigned higher_limit,
Label* on_in_range) {
if (lower_limit != 0) {
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireW();
Sub(scratch, value, Operand(lower_limit));
CompareAndBranch(scratch, Operand(higher_limit - lower_limit), ls,
on_in_range);
} else {
CompareAndBranch(value, Operand(higher_limit - lower_limit), ls,
on_in_range);
}
}
void TurboAssembler::LoadTaggedPointerField(const Register& destination,
const MemOperand& field_operand) {
#ifdef V8_COMPRESS_POINTERS
DecompressTaggedPointer(destination, field_operand);
#else
Ldr(destination, field_operand);
#endif
}
void TurboAssembler::LoadAnyTaggedField(const Register& destination,
const MemOperand& field_operand) {
#ifdef V8_COMPRESS_POINTERS
DecompressAnyTagged(destination, field_operand);
#else
Ldr(destination, field_operand);
#endif
}
void TurboAssembler::SmiUntagField(Register dst, const MemOperand& src) {
SmiUntag(dst, src);
}
void TurboAssembler::StoreTaggedField(const Register& value,
const MemOperand& dst_field_operand) {
#ifdef V8_COMPRESS_POINTERS
RecordComment("[ StoreTagged");
Str(value.W(), dst_field_operand);
RecordComment("]");
#else
Str(value, dst_field_operand);
#endif
}
void TurboAssembler::DecompressTaggedSigned(const Register& destination,
const MemOperand& field_operand) {
RecordComment("[ DecompressTaggedSigned");
Ldrsw(destination, field_operand);
RecordComment("]");
}
void TurboAssembler::DecompressTaggedSigned(const Register& destination,
const Register& source) {
RecordComment("[ DecompressTaggedSigned");
Sxtw(destination, source);
RecordComment("]");
}
void TurboAssembler::DecompressTaggedPointer(const Register& destination,
const MemOperand& field_operand) {
RecordComment("[ DecompressTaggedPointer");
Ldrsw(destination, field_operand);
Add(destination, kRootRegister, destination);
RecordComment("]");
}
void TurboAssembler::DecompressTaggedPointer(const Register& destination,
const Register& source) {
RecordComment("[ DecompressTaggedPointer");
Add(destination, kRootRegister, Operand(source, SXTW));
RecordComment("]");
}
void TurboAssembler::DecompressAnyTagged(const Register& destination,
const MemOperand& field_operand) {
RecordComment("[ DecompressAnyTagged");
Ldrsw(destination, field_operand);
if (kUseBranchlessPtrDecompressionInGeneratedCode) {
UseScratchRegisterScope temps(this);
// Branchlessly compute |masked_root|:
// masked_root = HAS_SMI_TAG(destination) ? 0 : kRootRegister;
STATIC_ASSERT((kSmiTagSize == 1) && (kSmiTag == 0));
Register masked_root = temps.AcquireX();
// Sign extend tag bit to entire register.
Sbfx(masked_root, destination, 0, kSmiTagSize);
And(masked_root, masked_root, kRootRegister);
// Now this add operation will either leave the value unchanged if it is a
// smi or add the isolate root if it is a heap object.
Add(destination, masked_root, destination);
} else {
Label done;
JumpIfSmi(destination, &done);
Add(destination, kRootRegister, destination);
bind(&done);
}
RecordComment("]");
}
void TurboAssembler::DecompressAnyTagged(const Register& destination,
const Register& source) {
RecordComment("[ DecompressAnyTagged");
if (kUseBranchlessPtrDecompressionInGeneratedCode) {
UseScratchRegisterScope temps(this);
// Branchlessly compute |masked_root|:
// masked_root = HAS_SMI_TAG(destination) ? 0 : kRootRegister;
STATIC_ASSERT((kSmiTagSize == 1) && (kSmiTag == 0));
Register masked_root = temps.AcquireX();
// Sign extend tag bit to entire register.
Sbfx(masked_root, source, 0, kSmiTagSize);
And(masked_root, masked_root, kRootRegister);
// Now this add operation will either leave the value unchanged if it is a
// smi or add the isolate root if it is a heap object.
Add(destination, masked_root, Operand(source, SXTW));
} else {
Label done;
Sxtw(destination, source);
JumpIfSmi(destination, &done);
Add(destination, kRootRegister, destination);
bind(&done);
}
RecordComment("]");
}
int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
// Make sure the safepoint registers list is what we expect.
DCHECK_EQ(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.
// - x31 (sp) 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 <= 30)) {
// Skip ip0 and ip1.
return reg_code - 2;
} else {
// This register has no safepoint register slot.
UNREACHABLE();
}
}
void TurboAssembler::CheckPageFlag(const Register& object, int mask,
Condition cc, Label* condition_met) {
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
And(scratch, object, ~kPageAlignmentMask);
Ldr(scratch, MemOperand(scratch, MemoryChunk::kFlagsOffset));
if (cc == eq) {
TestAndBranchIfAnySet(scratch, mask, condition_met);
} else {
DCHECK_EQ(cc, ne);
TestAndBranchIfAllClear(scratch, mask, condition_met);
}
}
void MacroAssembler::RecordWriteField(Register object, int offset,
Register value,
LinkRegisterStatus lr_status,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
SmiCheck smi_check) {
// 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 kTaggedSize.
DCHECK(IsAligned(offset, kTaggedSize));
if (emit_debug_code()) {
Label ok;
UseScratchRegisterScope temps(this);
Register scratch = temps.AcquireX();
Add(scratch, object, offset - kHeapObjectTag);
Tst(scratch, kTaggedSize - 1);
B(eq, &ok);
Abort(AbortReason::kUnalignedCellInWriteBarrier);
Bind(&ok);
}
RecordWrite(object, Operand(offset - kHeapObjectTag), value, lr_status,
save_fp, remembered_set_action, OMIT_SMI_CHECK);
Bind(&done);
}
void TurboAssembler::SaveRegisters(RegList registers) {
DCHECK_GT(NumRegs(registers), 0);
CPURegList regs(lr);
for (int i = 0; i < Register::kNumRegisters; ++i) {
if ((registers >> i) & 1u) {
regs.Combine(Register::XRegFromCode(i));
}
}
PushCPURegList(regs);
}
void TurboAssembler::RestoreRegisters(RegList registers) {
DCHECK_GT(NumRegs(registers), 0);
CPURegList regs(lr);
for (int i = 0; i < Register::kNumRegisters; ++i) {
if ((registers >> i) & 1u) {
regs.Combine(Register::XRegFromCode(i));
}
}
PopCPURegList(regs);
}
void TurboAssembler::CallEphemeronKeyBarrier(Register object, Operand offset,
SaveFPRegsMode fp_mode) {
EphemeronKeyBarrierDescriptor descriptor;
RegList registers = descriptor.allocatable_registers();
SaveRegisters(registers);
Register object_parameter(
descriptor.GetRegisterParameter(EphemeronKeyBarrierDescriptor::kObject));
Register slot_parameter(descriptor.GetRegisterParameter(
EphemeronKeyBarrierDescriptor::kSlotAddress));
Register fp_mode_parameter(
descriptor.GetRegisterParameter(EphemeronKeyBarrierDescriptor::kFPMode));
MoveObjectAndSlot(object_parameter, slot_parameter, object, offset);
Mov(fp_mode_parameter, Smi::FromEnum(fp_mode));
Call(isolate()->builtins()->builtin_handle(Builtins::kEphemeronKeyBarrier),
RelocInfo::CODE_TARGET);
RestoreRegisters(registers);
}
void TurboAssembler::CallRecordWriteStub(
Register object, Operand offset, RememberedSetAction remembered_set_action,
SaveFPRegsMode fp_mode) {
CallRecordWriteStub(
object, offset, remembered_set_action, fp_mode,
isolate()->builtins()->builtin_handle(Builtins::kRecordWrite),
kNullAddress);
}
void TurboAssembler::CallRecordWriteStub(
Register object, Operand offset, RememberedSetAction remembered_set_action,
SaveFPRegsMode fp_mode, Address wasm_target) {
CallRecordWriteStub(object, offset, remembered_set_action, fp_mode,
Handle<Code>::null(), wasm_target);
}
void TurboAssembler::CallRecordWriteStub(
Register object, Operand offset, RememberedSetAction remembered_set_action,
SaveFPRegsMode fp_mode, Handle<Code> code_target, Address wasm_target) {
DCHECK_NE(code_target.is_null(), wasm_target == kNullAddress);
// TODO(albertnetymk): For now we ignore remembered_set_action and fp_mode,
// i.e. always emit remember set and save FP registers in RecordWriteStub. If
// large performance regression is observed, we should use these values to
// avoid unnecessary work.
RecordWriteDescriptor descriptor;
RegList registers = descriptor.allocatable_registers();
SaveRegisters(registers);
Register object_parameter(
descriptor.GetRegisterParameter(RecordWriteDescriptor::kObject));
Register slot_parameter(
descriptor.GetRegisterParameter(RecordWriteDescriptor::kSlot));
Register remembered_set_parameter(
descriptor.GetRegisterParameter(RecordWriteDescriptor::kRememberedSet));
Register fp_mode_parameter(
descriptor.GetRegisterParameter(RecordWriteDescriptor::kFPMode));
MoveObjectAndSlot(object_parameter, slot_parameter, object, offset);
Mov(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
Mov(fp_mode_parameter, Smi::FromEnum(fp_mode));
if (code_target.is_null()) {
Call(wasm_target, RelocInfo::WASM_STUB_CALL);
} else {
Call(code_target, RelocInfo::CODE_TARGET);
}
RestoreRegisters(registers);
}
void TurboAssembler::MoveObjectAndSlot(Register dst_object, Register dst_slot,
Register object, Operand offset) {
DCHECK_NE(dst_object, dst_slot);
// If `offset` is a register, it cannot overlap with `object`.
DCHECK_IMPLIES(!offset.IsImmediate(), offset.reg() != object);
// If the slot register does not overlap with the object register, we can
// overwrite it.
if (dst_slot != object) {
Add(dst_slot, object, offset);
Mov(dst_object, object);
return;
}
DCHECK_EQ(dst_slot, object);
// If the destination object register does not overlap with the offset
// register, we can overwrite it.
if (offset.IsImmediate() || (offset.reg() != dst_object)) {
Mov(dst_object, dst_slot);
Add(dst_slot, dst_slot, offset);
return;
}
DCHECK_EQ(dst_object, offset.reg());
// We only have `dst_slot` and `dst_object` left as distinct registers so we
// have to swap them. We write this as a add+sub sequence to avoid using a
// scratch register.
Add(dst_slot, dst_slot, dst_object);
Sub(dst_object, dst_slot, dst_object);
}
// If lr_status is kLRHasBeenSaved, lr will be clobbered.
//
// The register 'object' contains a heap object pointer. The heap object tag is
// shifted away.
void MacroAssembler::RecordWrite(Register object, Operand offset,
Register value, LinkRegisterStatus lr_status,
SaveFPRegsMode fp_mode,
RememberedSetAction remembered_set_action,
SmiCheck smi_check) {
ASM_LOCATION_IN_ASSEMBLER("MacroAssembler::RecordWrite");
DCHECK(!AreAliased(object, value));
if (emit_debug_code()) {
UseScratchRegisterScope temps(this);
Register temp = temps.AcquireX();
Add(temp, object, offset);
LoadTaggedPointerField(temp, MemOperand(temp));
Cmp(temp, value);
Check(eq, AbortReason::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);
}
CheckPageFlag(value, MemoryChunk::kPointersToHereAreInterestingMask, ne,
&done);
CheckPageFlag(object, MemoryChunk::kPointersFromHereAreInterestingMask, ne,
&done);
// Record the actual write.
if (lr_status == kLRHasNotBeenSaved) {
Push(padreg, lr);
}
CallRecordWriteStub(object, offset, remembered_set_action, fp_mode);
if (lr_status == kLRHasNotBeenSaved) {
Pop(lr, padreg);
}
Bind(&done);
}
void TurboAssembler::Assert(Condition cond, AbortReason reason) {
if (emit_debug_code()) {
Check(cond, reason);
}
}
void TurboAssembler::AssertUnreachable(AbortReason reason) {
if (emit_debug_code()) Abort(reason);
}
void MacroAssembler::AssertRegisterIsRoot(Register reg, RootIndex index,
AbortReason reason) {
if (emit_debug_code()) {
CompareRoot(reg, index);
Check(eq, reason);
}
}
void TurboAssembler::Check(Condition cond, AbortReason reason) {
Label ok;
B(cond, &ok);
Abort(reason);
// Will not return here.
Bind(&ok);
}
void TurboAssembler::Abort(AbortReason reason) {
#ifdef DEBUG
RecordComment("Abort message: ");
RecordComment(GetAbortReason(reason));
#endif
// Avoid emitting call to builtin if requested.
if (trap_on_abort()) {
Brk(0);
return;
}
// 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 (should_abort_hard()) {
// We don't care if we constructed a frame. Just pretend we did.
FrameScope assume_frame(this, StackFrame::NONE);
Mov(w0, static_cast<int>(reason));
Call(ExternalReference::abort_with_reason());
return;
}
// Avoid infinite recursion; Push contains some assertions that use Abort.
HardAbortScope hard_aborts(this);
Mov(x1, Smi::FromInt(static_cast<int>(reason)));
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);
Call(BUILTIN_CODE(isolate(), Abort), RelocInfo::CODE_TARGET);
} else {
Call(BUILTIN_CODE(isolate(), Abort), RelocInfo::CODE_TARGET);
}
TmpList()->set_list(old_tmp_list);
}
void MacroAssembler::LoadNativeContextSlot(int index, Register dst) {
LoadTaggedPointerField(dst, NativeContextMemOperand());
LoadTaggedPointerField(dst, ContextMemOperand(dst, index));
}
// 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(sp));
// 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::kVRegister, 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 = kCallerSavedV;
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].IsVRegister()) {
// 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 = args[i].Reg();
Register new_arg = temps.AcquireSameSizeAs(old_arg);
Mov(new_arg, old_arg);
args[i] = new_arg;
} else {
VRegister old_arg = args[i].VReg();
VRegister 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(pcs[i].Reg(), args[i].Reg(), kDiscardForSameWReg);
} else {
DCHECK(pcs[i].IsVRegister());
if (pcs[i].SizeInBytes() == args[i].SizeInBytes()) {
Fmov(pcs[i].VReg(), args[i].VReg());
} else {
Fcvt(pcs[i].VReg(), args[i].VReg());
}
}
}
// 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);
}
CallPrintf(arg_count, pcs);
}
void TurboAssembler::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 / kInstrSize);
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(ExternalReference::printf_function());
#endif
}
void MacroAssembler::Printf(const char* format, CPURegister arg0,
CPURegister arg1, CPURegister arg2,
CPURegister 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);
CPURegList saved_registers = kCallerSaved;
saved_registers.Align();
// Preserve all caller-saved registers as well as NZCV.
// PushCPURegList asserts that the size of each list is a multiple of 16
// bytes.
PushCPURegList(saved_registers);
PushCPURegList(kCallerSavedV);
// We can use caller-saved registers as scratch values (except for argN).
CPURegList tmp_list = saved_registers;
CPURegList fp_tmp_list = kCallerSavedV;
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 = sp.Aliases(arg0);
bool arg1_sp = sp.Aliases(arg1);
bool arg2_sp = sp.Aliases(arg2);
bool arg3_sp = sp.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, sp,
saved_registers.TotalSizeInBytes() +
kCallerSavedV.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(kCallerSavedV);
PopCPURegList(saved_registers);
TmpList()->set_list(old_tmp_list);
FPTmpList()->set_list(old_fp_tmp_list);
}
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());
}
VRegister UseScratchRegisterScope::AcquireSameSizeAs(const VRegister& reg) {
int code = AcquireNextAvailable(availablefp_).code();
return VRegister::Create(code, reg.SizeInBits());
}
CPURegister UseScratchRegisterScope::AcquireNextAvailable(
CPURegList* available) {
CHECK(!available->IsEmpty());
CPURegister result = available->PopLowestIndex();
DCHECK(!AreAliased(result, xzr, sp));
return result;
}
MemOperand ContextMemOperand(Register context, int index) {
return MemOperand(context, Context::SlotOffset(index));
}
MemOperand NativeContextMemOperand() {
return ContextMemOperand(cp, Context::NATIVE_CONTEXT_INDEX);
}
void TurboAssembler::ComputeCodeStartAddress(const Register& rd) {
// We can use adr to load a pc relative location.
adr(rd, -pc_offset());
}
void TurboAssembler::ResetSpeculationPoisonRegister() {
Mov(kSpeculationPoisonRegister, -1);
}
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_ARM64