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chromium / v8 / v8 / 3d4f85ab9f38340082519dea318bfe2ad967a5a5 / . / src / arm64 / assembler-arm64.cc
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// Copyright 2013 the V8 project authors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#if V8_TARGET_ARCH_ARM64
#define ARM64_DEFINE_REG_STATICS
#include "src/arm64/assembler-arm64.h"
#include "src/arm64/assembler-arm64-inl.h"
#include "src/arm64/frames-arm64.h"
#include "src/base/bits.h"
#include "src/base/cpu.h"
#include "src/register-configuration.h"
namespace v8 {
namespace internal {
// -----------------------------------------------------------------------------
// CpuFeatures implementation.
void CpuFeatures::ProbeImpl(bool cross_compile) {
// AArch64 has no configuration options, no further probing is required.
supported_ = 0;
// Only use statically determined features for cross compile (snapshot).
if (cross_compile) return;
// Probe for runtime features
base::CPU cpu;
if (cpu.implementer() == base::CPU::NVIDIA &&
cpu.variant() == base::CPU::NVIDIA_DENVER &&
cpu.part() <= base::CPU::NVIDIA_DENVER_V10) {
// TODO(jkummerow): This is turned off as an experiment to see if it
// affects crash rates. Keep an eye on crash reports and either remove
// coherent cache support permanently, or re-enable it!
// supported_ |= 1u << COHERENT_CACHE;
}
}
void CpuFeatures::PrintTarget() { }
void CpuFeatures::PrintFeatures() {
printf("COHERENT_CACHE=%d\n", CpuFeatures::IsSupported(COHERENT_CACHE));
}
// -----------------------------------------------------------------------------
// CPURegList utilities.
CPURegister CPURegList::PopLowestIndex() {
DCHECK(IsValid());
if (IsEmpty()) {
return NoCPUReg;
}
int index = CountTrailingZeros(list_, kRegListSizeInBits);
DCHECK((1 << index) & list_);
Remove(index);
return CPURegister::Create(index, size_, type_);
}
CPURegister CPURegList::PopHighestIndex() {
DCHECK(IsValid());
if (IsEmpty()) {
return NoCPUReg;
}
int index = CountLeadingZeros(list_, kRegListSizeInBits);
index = kRegListSizeInBits - 1 - index;
DCHECK((1 << index) & list_);
Remove(index);
return CPURegister::Create(index, size_, type_);
}
void CPURegList::RemoveCalleeSaved() {
if (type() == CPURegister::kRegister) {
Remove(GetCalleeSaved(RegisterSizeInBits()));
} else if (type() == CPURegister::kFPRegister) {
Remove(GetCalleeSavedFP(RegisterSizeInBits()));
} else {
DCHECK(type() == CPURegister::kNoRegister);
DCHECK(IsEmpty());
// The list must already be empty, so do nothing.
}
}
CPURegList CPURegList::GetCalleeSaved(int size) {
return CPURegList(CPURegister::kRegister, size, 19, 29);
}
CPURegList CPURegList::GetCalleeSavedFP(int size) {
return CPURegList(CPURegister::kFPRegister, size, 8, 15);
}
CPURegList CPURegList::GetCallerSaved(int size) {
// Registers x0-x18 and lr (x30) are caller-saved.
CPURegList list = CPURegList(CPURegister::kRegister, size, 0, 18);
list.Combine(lr);
return list;
}
CPURegList CPURegList::GetCallerSavedFP(int size) {
// Registers d0-d7 and d16-d31 are caller-saved.
CPURegList list = CPURegList(CPURegister::kFPRegister, size, 0, 7);
list.Combine(CPURegList(CPURegister::kFPRegister, size, 16, 31));
return list;
}
// This function defines the list of registers which are associated with a
// safepoint slot. Safepoint register slots are saved contiguously on the stack.
// MacroAssembler::SafepointRegisterStackIndex handles mapping from register
// code to index in the safepoint register slots. Any change here can affect
// this mapping.
CPURegList CPURegList::GetSafepointSavedRegisters() {
CPURegList list = CPURegList::GetCalleeSaved();
list.Combine(
CPURegList(CPURegister::kRegister, kXRegSizeInBits, kJSCallerSaved));
// Note that unfortunately we can't use symbolic names for registers and have
// to directly use register codes. This is because this function is used to
// initialize some static variables and we can't rely on register variables
// to be initialized due to static initialization order issues in C++.
// Drop ip0 and ip1 (i.e. x16 and x17), as they should not be expected to be
// preserved outside of the macro assembler.
list.Remove(16);
list.Remove(17);
// Add x18 to the safepoint list, as although it's not in kJSCallerSaved, it
// is a caller-saved register according to the procedure call standard.
list.Combine(18);
// Drop jssp as the stack pointer doesn't need to be included.
list.Remove(28);
// Add the link register (x30) to the safepoint list.
list.Combine(30);
return list;
}
// -----------------------------------------------------------------------------
// Implementation of RelocInfo
const int RelocInfo::kApplyMask = 1 << RelocInfo::INTERNAL_REFERENCE;
bool RelocInfo::IsCodedSpecially() {
// The deserializer needs to know whether a pointer is specially coded. Being
// specially coded on ARM64 means that it is a movz/movk sequence. We don't
// generate those for relocatable pointers.
return false;
}
bool RelocInfo::IsInConstantPool() {
Instruction* instr = reinterpret_cast<Instruction*>(pc_);
return instr->IsLdrLiteralX();
}
Register GetAllocatableRegisterThatIsNotOneOf(Register reg1, Register reg2,
Register reg3, Register reg4) {
CPURegList regs(reg1, reg2, reg3, reg4);
const RegisterConfiguration* config =
RegisterConfiguration::ArchDefault(RegisterConfiguration::CRANKSHAFT);
for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
int code = config->GetAllocatableDoubleCode(i);
Register candidate = Register::from_code(code);
if (regs.IncludesAliasOf(candidate)) continue;
return candidate;
}
UNREACHABLE();
return NoReg;
}
bool AreAliased(const CPURegister& reg1, const CPURegister& reg2,
const CPURegister& reg3, const CPURegister& reg4,
const CPURegister& reg5, const CPURegister& reg6,
const CPURegister& reg7, const CPURegister& reg8) {
int number_of_valid_regs = 0;
int number_of_valid_fpregs = 0;
RegList unique_regs = 0;
RegList unique_fpregs = 0;
const CPURegister regs[] = {reg1, reg2, reg3, reg4, reg5, reg6, reg7, reg8};
for (unsigned i = 0; i < arraysize(regs); i++) {
if (regs[i].IsRegister()) {
number_of_valid_regs++;
unique_regs |= regs[i].Bit();
} else if (regs[i].IsFPRegister()) {
number_of_valid_fpregs++;
unique_fpregs |= regs[i].Bit();
} else {
DCHECK(!regs[i].IsValid());
}
}
int number_of_unique_regs =
CountSetBits(unique_regs, sizeof(unique_regs) * kBitsPerByte);
int number_of_unique_fpregs =
CountSetBits(unique_fpregs, sizeof(unique_fpregs) * kBitsPerByte);
DCHECK(number_of_valid_regs >= number_of_unique_regs);
DCHECK(number_of_valid_fpregs >= number_of_unique_fpregs);
return (number_of_valid_regs != number_of_unique_regs) ||
(number_of_valid_fpregs != number_of_unique_fpregs);
}
bool AreSameSizeAndType(const CPURegister& reg1, const CPURegister& reg2,
const CPURegister& reg3, const CPURegister& reg4,
const CPURegister& reg5, const CPURegister& reg6,
const CPURegister& reg7, const CPURegister& reg8) {
DCHECK(reg1.IsValid());
bool match = true;
match &= !reg2.IsValid() || reg2.IsSameSizeAndType(reg1);
match &= !reg3.IsValid() || reg3.IsSameSizeAndType(reg1);
match &= !reg4.IsValid() || reg4.IsSameSizeAndType(reg1);
match &= !reg5.IsValid() || reg5.IsSameSizeAndType(reg1);
match &= !reg6.IsValid() || reg6.IsSameSizeAndType(reg1);
match &= !reg7.IsValid() || reg7.IsSameSizeAndType(reg1);
match &= !reg8.IsValid() || reg8.IsSameSizeAndType(reg1);
return match;
}
void Immediate::InitializeHandle(Handle<Object> handle) {
AllowDeferredHandleDereference using_raw_address;
// Verify all Objects referred by code are NOT in new space.
Object* obj = *handle;
if (obj->IsHeapObject()) {
DCHECK(!HeapObject::cast(obj)->GetHeap()->InNewSpace(obj));
value_ = reinterpret_cast<intptr_t>(handle.location());
rmode_ = RelocInfo::EMBEDDED_OBJECT;
} else {
STATIC_ASSERT(sizeof(intptr_t) == sizeof(int64_t));
value_ = reinterpret_cast<intptr_t>(obj);
rmode_ = RelocInfo::NONE64;
}
}
bool Operand::NeedsRelocation(const Assembler* assembler) const {
RelocInfo::Mode rmode = immediate_.rmode();
if (rmode == RelocInfo::EXTERNAL_REFERENCE) {
return assembler->serializer_enabled();
}
return !RelocInfo::IsNone(rmode);
}
// Constant Pool.
void ConstPool::RecordEntry(intptr_t data,
RelocInfo::Mode mode) {
DCHECK(mode != RelocInfo::COMMENT &&
mode != RelocInfo::POSITION &&
mode != RelocInfo::STATEMENT_POSITION &&
mode != RelocInfo::CONST_POOL &&
mode != RelocInfo::VENEER_POOL &&
mode != RelocInfo::CODE_AGE_SEQUENCE &&
mode != RelocInfo::DEOPT_REASON);
uint64_t raw_data = static_cast<uint64_t>(data);
int offset = assm_->pc_offset();
if (IsEmpty()) {
first_use_ = offset;
}
std::pair<uint64_t, int> entry = std::make_pair(raw_data, offset);
if (CanBeShared(mode)) {
shared_entries_.insert(entry);
if (shared_entries_.count(entry.first) == 1) {
shared_entries_count++;
}
} else {
unique_entries_.push_back(entry);
}
if (EntryCount() > Assembler::kApproxMaxPoolEntryCount) {
// Request constant pool emission after the next instruction.
assm_->SetNextConstPoolCheckIn(1);
}
}
int ConstPool::DistanceToFirstUse() {
DCHECK(first_use_ >= 0);
return assm_->pc_offset() - first_use_;
}
int ConstPool::MaxPcOffset() {
// There are no pending entries in the pool so we can never get out of
// range.
if (IsEmpty()) return kMaxInt;
// Entries are not necessarily emitted in the order they are added so in the
// worst case the first constant pool use will be accessing the last entry.
return first_use_ + kMaxLoadLiteralRange - WorstCaseSize();
}
int ConstPool::WorstCaseSize() {
if (IsEmpty()) return 0;
// Max size prologue:
// b over
// ldr xzr, #pool_size
// blr xzr
// nop
// All entries are 64-bit for now.
return 4 * kInstructionSize + EntryCount() * kPointerSize;
}
int ConstPool::SizeIfEmittedAtCurrentPc(bool require_jump) {
if (IsEmpty()) return 0;
// Prologue is:
// b over ;; if require_jump
// ldr xzr, #pool_size
// blr xzr
// nop ;; if not 64-bit aligned
int prologue_size = require_jump ? kInstructionSize : 0;
prologue_size += 2 * kInstructionSize;
prologue_size += IsAligned(assm_->pc_offset() + prologue_size, 8) ?
0 : kInstructionSize;
// All entries are 64-bit for now.
return prologue_size + EntryCount() * kPointerSize;
}
void ConstPool::Emit(bool require_jump) {
DCHECK(!assm_->is_const_pool_blocked());
// Prevent recursive pool emission and protect from veneer pools.
Assembler::BlockPoolsScope block_pools(assm_);
int size = SizeIfEmittedAtCurrentPc(require_jump);
Label size_check;
assm_->bind(&size_check);
assm_->RecordConstPool(size);
// Emit the constant pool. It is preceded by an optional branch if
// require_jump and a header which will:
// 1) Encode the size of the constant pool, for use by the disassembler.
// 2) Terminate the program, to try to prevent execution from accidentally
// flowing into the constant pool.
// 3) align the pool entries to 64-bit.
// The header is therefore made of up to three arm64 instructions:
// ldr xzr, #<size of the constant pool in 32-bit words>
// blr xzr
// nop
//
// If executed, the header will likely segfault and lr will point to the
// instruction following the offending blr.
// TODO(all): Make the alignment part less fragile. Currently code is
// allocated as a byte array so there are no guarantees the alignment will
// be preserved on compaction. Currently it works as allocation seems to be
// 64-bit aligned.
// Emit branch if required
Label after_pool;
if (require_jump) {
assm_->b(&after_pool);
}
// Emit the header.
assm_->RecordComment("[ Constant Pool");
EmitMarker();
EmitGuard();
assm_->Align(8);
// Emit constant pool entries.
// TODO(all): currently each relocated constant is 64 bits, consider adding
// support for 32-bit entries.
EmitEntries();
assm_->RecordComment("]");
if (after_pool.is_linked()) {
assm_->bind(&after_pool);
}
DCHECK(assm_->SizeOfCodeGeneratedSince(&size_check) ==
static_cast<unsigned>(size));
}
void ConstPool::Clear() {
shared_entries_.clear();
shared_entries_count = 0;
unique_entries_.clear();
first_use_ = -1;
}
bool ConstPool::CanBeShared(RelocInfo::Mode mode) {
// Constant pool currently does not support 32-bit entries.
DCHECK(mode != RelocInfo::NONE32);
return RelocInfo::IsNone(mode) ||
(!assm_->serializer_enabled() &&
(mode >= RelocInfo::FIRST_SHAREABLE_RELOC_MODE));
}
void ConstPool::EmitMarker() {
// A constant pool size is expressed in number of 32-bits words.
// Currently all entries are 64-bit.
// + 1 is for the crash guard.
// + 0/1 for alignment.
int word_count = EntryCount() * 2 + 1 +
(IsAligned(assm_->pc_offset(), 8) ? 0 : 1);
assm_->Emit(LDR_x_lit |
Assembler::ImmLLiteral(word_count) |
Assembler::Rt(xzr));
}
MemOperand::PairResult MemOperand::AreConsistentForPair(
const MemOperand& operandA,
const MemOperand& operandB,
int access_size_log2) {
DCHECK(access_size_log2 >= 0);
DCHECK(access_size_log2 <= 3);
// Step one: check that they share the same base, that the mode is Offset
// and that the offset is a multiple of access size.
if (!operandA.base().Is(operandB.base()) ||
(operandA.addrmode() != Offset) ||
(operandB.addrmode() != Offset) ||
((operandA.offset() & ((1 << access_size_log2) - 1)) != 0)) {
return kNotPair;
}
// Step two: check that the offsets are contiguous and that the range
// is OK for ldp/stp.
if ((operandB.offset() == operandA.offset() + (1 << access_size_log2)) &&
is_int7(operandA.offset() >> access_size_log2)) {
return kPairAB;
}
if ((operandA.offset() == operandB.offset() + (1 << access_size_log2)) &&
is_int7(operandB.offset() >> access_size_log2)) {
return kPairBA;
}
return kNotPair;
}
void ConstPool::EmitGuard() {
#ifdef DEBUG
Instruction* instr = reinterpret_cast<Instruction*>(assm_->pc());
DCHECK(instr->preceding()->IsLdrLiteralX() &&
instr->preceding()->Rt() == xzr.code());
#endif
assm_->EmitPoolGuard();
}
void ConstPool::EmitEntries() {
DCHECK(IsAligned(assm_->pc_offset(), 8));
typedef std::multimap<uint64_t, int>::const_iterator SharedEntriesIterator;
SharedEntriesIterator value_it;
// Iterate through the keys (constant pool values).
for (value_it = shared_entries_.begin();
value_it != shared_entries_.end();
value_it = shared_entries_.upper_bound(value_it->first)) {
std::pair<SharedEntriesIterator, SharedEntriesIterator> range;
uint64_t data = value_it->first;
range = shared_entries_.equal_range(data);
SharedEntriesIterator offset_it;
// Iterate through the offsets of a given key.
for (offset_it = range.first; offset_it != range.second; offset_it++) {
Instruction* instr = assm_->InstructionAt(offset_it->second);
// Instruction to patch must be 'ldr rd, [pc, #offset]' with offset == 0.
DCHECK(instr->IsLdrLiteral() && instr->ImmLLiteral() == 0);
instr->SetImmPCOffsetTarget(assm_->isolate(), assm_->pc());
}
assm_->dc64(data);
}
shared_entries_.clear();
shared_entries_count = 0;
// Emit unique entries.
std::vector<std::pair<uint64_t, int> >::const_iterator unique_it;
for (unique_it = unique_entries_.begin();
unique_it != unique_entries_.end();
unique_it++) {
Instruction* instr = assm_->InstructionAt(unique_it->second);
// Instruction to patch must be 'ldr rd, [pc, #offset]' with offset == 0.
DCHECK(instr->IsLdrLiteral() && instr->ImmLLiteral() == 0);
instr->SetImmPCOffsetTarget(assm_->isolate(), assm_->pc());
assm_->dc64(unique_it->first);
}
unique_entries_.clear();
first_use_ = -1;
}
// Assembler
Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
: AssemblerBase(isolate, buffer, buffer_size),
constpool_(this),
recorded_ast_id_(TypeFeedbackId::None()),
unresolved_branches_(),
positions_recorder_(this) {
const_pool_blocked_nesting_ = 0;
veneer_pool_blocked_nesting_ = 0;
Reset();
}
Assembler::~Assembler() {
DCHECK(constpool_.IsEmpty());
DCHECK(const_pool_blocked_nesting_ == 0);
DCHECK(veneer_pool_blocked_nesting_ == 0);
}
void Assembler::Reset() {
#ifdef DEBUG
DCHECK((pc_ >= buffer_) && (pc_ < buffer_ + buffer_size_));
DCHECK(const_pool_blocked_nesting_ == 0);
DCHECK(veneer_pool_blocked_nesting_ == 0);
DCHECK(unresolved_branches_.empty());
memset(buffer_, 0, pc_ - buffer_);
#endif
pc_ = buffer_;
reloc_info_writer.Reposition(reinterpret_cast<byte*>(buffer_ + buffer_size_),
reinterpret_cast<byte*>(pc_));
constpool_.Clear();
next_constant_pool_check_ = 0;
next_veneer_pool_check_ = kMaxInt;
no_const_pool_before_ = 0;
ClearRecordedAstId();
}
void Assembler::GetCode(CodeDesc* desc) {
reloc_info_writer.Finish();
// Emit constant pool if necessary.
CheckConstPool(true, false);
DCHECK(constpool_.IsEmpty());
// Set up code descriptor.
if (desc) {
desc->buffer = reinterpret_cast<byte*>(buffer_);
desc->buffer_size = buffer_size_;
desc->instr_size = pc_offset();
desc->reloc_size =
static_cast<int>((reinterpret_cast<byte*>(buffer_) + buffer_size_) -
reloc_info_writer.pos());
desc->origin = this;
desc->constant_pool_size = 0;
}
}
void Assembler::Align(int m) {
DCHECK(m >= 4 && base::bits::IsPowerOfTwo32(m));
while ((pc_offset() & (m - 1)) != 0) {
nop();
}
}
void Assembler::CheckLabelLinkChain(Label const * label) {
#ifdef DEBUG
if (label->is_linked()) {
static const int kMaxLinksToCheck = 64; // Avoid O(n2) behaviour.
int links_checked = 0;
int64_t linkoffset = label->pos();
bool end_of_chain = false;
while (!end_of_chain) {
if (++links_checked > kMaxLinksToCheck) break;
Instruction * link = InstructionAt(linkoffset);
int64_t linkpcoffset = link->ImmPCOffset();
int64_t prevlinkoffset = linkoffset + linkpcoffset;
end_of_chain = (linkoffset == prevlinkoffset);
linkoffset = linkoffset + linkpcoffset;
}
}
#endif
}
void Assembler::RemoveBranchFromLabelLinkChain(Instruction* branch,
Label* label,
Instruction* label_veneer) {
DCHECK(label->is_linked());
CheckLabelLinkChain(label);
Instruction* link = InstructionAt(label->pos());
Instruction* prev_link = link;
Instruction* next_link;
bool end_of_chain = false;
while (link != branch && !end_of_chain) {
next_link = link->ImmPCOffsetTarget();
end_of_chain = (link == next_link);
prev_link = link;
link = next_link;
}
DCHECK(branch == link);
next_link = branch->ImmPCOffsetTarget();
if (branch == prev_link) {
// The branch is the first instruction in the chain.
if (branch == next_link) {
// It is also the last instruction in the chain, so it is the only branch
// currently referring to this label.
label->Unuse();
} else {
label->link_to(
static_cast<int>(reinterpret_cast<byte*>(next_link) - buffer_));
}
} else if (branch == next_link) {
// The branch is the last (but not also the first) instruction in the chain.
prev_link->SetImmPCOffsetTarget(isolate(), prev_link);
} else {
// The branch is in the middle of the chain.
if (prev_link->IsTargetInImmPCOffsetRange(next_link)) {
prev_link->SetImmPCOffsetTarget(isolate(), next_link);
} else if (label_veneer != NULL) {
// Use the veneer for all previous links in the chain.
prev_link->SetImmPCOffsetTarget(isolate(), prev_link);
end_of_chain = false;
link = next_link;
while (!end_of_chain) {
next_link = link->ImmPCOffsetTarget();
end_of_chain = (link == next_link);
link->SetImmPCOffsetTarget(isolate(), label_veneer);
link = next_link;
}
} else {
// The assert below will fire.
// Some other work could be attempted to fix up the chain, but it would be
// rather complicated. If we crash here, we may want to consider using an
// other mechanism than a chain of branches.
//
// Note that this situation currently should not happen, as we always call
// this function with a veneer to the target label.
// However this could happen with a MacroAssembler in the following state:
// [previous code]
// B(label);
// [20KB code]
// Tbz(label); // First tbz. Pointing to unconditional branch.
// [20KB code]
// Tbz(label); // Second tbz. Pointing to the first tbz.
// [more code]
// and this function is called to remove the first tbz from the label link
// chain. Since tbz has a range of +-32KB, the second tbz cannot point to
// the unconditional branch.
CHECK(prev_link->IsTargetInImmPCOffsetRange(next_link));
UNREACHABLE();
}
}
CheckLabelLinkChain(label);
}
void Assembler::bind(Label* label) {
// Bind label to the address at pc_. All instructions (most likely branches)
// that are linked to this label will be updated to point to the newly-bound
// label.
DCHECK(!label->is_near_linked());
DCHECK(!label->is_bound());
DeleteUnresolvedBranchInfoForLabel(label);
// If the label is linked, the link chain looks something like this:
//
// |--I----I-------I-------L
// |---------------------->| pc_offset
// |-------------->| linkoffset = label->pos()
// |<------| link->ImmPCOffset()
// |------>| prevlinkoffset = linkoffset + link->ImmPCOffset()
//
// On each iteration, the last link is updated and then removed from the
// chain until only one remains. At that point, the label is bound.
//
// If the label is not linked, no preparation is required before binding.
while (label->is_linked()) {
int linkoffset = label->pos();
Instruction* link = InstructionAt(linkoffset);
int prevlinkoffset = linkoffset + static_cast<int>(link->ImmPCOffset());
CheckLabelLinkChain(label);
DCHECK(linkoffset >= 0);
DCHECK(linkoffset < pc_offset());
DCHECK((linkoffset > prevlinkoffset) ||
(linkoffset - prevlinkoffset == kStartOfLabelLinkChain));
DCHECK(prevlinkoffset >= 0);
// Update the link to point to the label.
if (link->IsUnresolvedInternalReference()) {
// Internal references do not get patched to an instruction but directly
// to an address.
internal_reference_positions_.push_back(linkoffset);
PatchingAssembler patcher(isolate(), link, 2);
patcher.dc64(reinterpret_cast<uintptr_t>(pc_));
} else {
link->SetImmPCOffsetTarget(isolate(),
reinterpret_cast<Instruction*>(pc_));
}
// Link the label to the previous link in the chain.
if (linkoffset - prevlinkoffset == kStartOfLabelLinkChain) {
// We hit kStartOfLabelLinkChain, so the chain is fully processed.
label->Unuse();
} else {
// Update the label for the next iteration.
label->link_to(prevlinkoffset);
}
}
label->bind_to(pc_offset());
DCHECK(label->is_bound());
DCHECK(!label->is_linked());
}
int Assembler::LinkAndGetByteOffsetTo(Label* label) {
DCHECK(sizeof(*pc_) == 1);
CheckLabelLinkChain(label);
int offset;
if (label->is_bound()) {
// The label is bound, so it does not need to be updated. Referring
// instructions must link directly to the label as they will not be
// updated.
//
// In this case, label->pos() returns the offset of the label from the
// start of the buffer.
//
// Note that offset can be zero for self-referential instructions. (This
// could be useful for ADR, for example.)
offset = label->pos() - pc_offset();
DCHECK(offset <= 0);
} else {
if (label->is_linked()) {
// The label is linked, so the referring instruction should be added onto
// the end of the label's link chain.
//
// In this case, label->pos() returns the offset of the last linked
// instruction from the start of the buffer.
offset = label->pos() - pc_offset();
DCHECK(offset != kStartOfLabelLinkChain);
// Note that the offset here needs to be PC-relative only so that the
// first instruction in a buffer can link to an unbound label. Otherwise,
// the offset would be 0 for this case, and 0 is reserved for
// kStartOfLabelLinkChain.
} else {
// The label is unused, so it now becomes linked and the referring
// instruction is at the start of the new link chain.
offset = kStartOfLabelLinkChain;
}
// The instruction at pc is now the last link in the label's chain.
label->link_to(pc_offset());
}
return offset;
}
void Assembler::DeleteUnresolvedBranchInfoForLabelTraverse(Label* label) {
DCHECK(label->is_linked());
CheckLabelLinkChain(label);
int link_offset = label->pos();
int link_pcoffset;
bool end_of_chain = false;
while (!end_of_chain) {
Instruction * link = InstructionAt(link_offset);
link_pcoffset = static_cast<int>(link->ImmPCOffset());
// ADR instructions are not handled by veneers.
if (link->IsImmBranch()) {
int max_reachable_pc =
static_cast<int>(InstructionOffset(link) +
Instruction::ImmBranchRange(link->BranchType()));
typedef std::multimap<int, FarBranchInfo>::iterator unresolved_info_it;
std::pair<unresolved_info_it, unresolved_info_it> range;
range = unresolved_branches_.equal_range(max_reachable_pc);
unresolved_info_it it;
for (it = range.first; it != range.second; ++it) {
if (it->second.pc_offset_ == link_offset) {
unresolved_branches_.erase(it);
break;
}
}
}
end_of_chain = (link_pcoffset == 0);
link_offset = link_offset + link_pcoffset;
}
}
void Assembler::DeleteUnresolvedBranchInfoForLabel(Label* label) {
if (unresolved_branches_.empty()) {
DCHECK(next_veneer_pool_check_ == kMaxInt);
return;
}
if (label->is_linked()) {
// Branches to this label will be resolved when the label is bound, normally
// just after all the associated info has been deleted.
DeleteUnresolvedBranchInfoForLabelTraverse(label);
}
if (unresolved_branches_.empty()) {
next_veneer_pool_check_ = kMaxInt;
} else {
next_veneer_pool_check_ =
unresolved_branches_first_limit() - kVeneerDistanceCheckMargin;
}
}
void Assembler::StartBlockConstPool() {
if (const_pool_blocked_nesting_++ == 0) {
// Prevent constant pool checks happening by setting the next check to
// the biggest possible offset.
next_constant_pool_check_ = kMaxInt;
}
}
void Assembler::EndBlockConstPool() {
if (--const_pool_blocked_nesting_ == 0) {
// Check the constant pool hasn't been blocked for too long.
DCHECK(pc_offset() < constpool_.MaxPcOffset());
// Two cases:
// * no_const_pool_before_ >= next_constant_pool_check_ and the emission is
// still blocked
// * no_const_pool_before_ < next_constant_pool_check_ and the next emit
// will trigger a check.
next_constant_pool_check_ = no_const_pool_before_;
}
}
bool Assembler::is_const_pool_blocked() const {
return (const_pool_blocked_nesting_ > 0) ||
(pc_offset() < no_const_pool_before_);
}
bool Assembler::IsConstantPoolAt(Instruction* instr) {
// The constant pool marker is made of two instructions. These instructions
// will never be emitted by the JIT, so checking for the first one is enough:
// 0: ldr xzr, #<size of pool>
bool result = instr->IsLdrLiteralX() && (instr->Rt() == kZeroRegCode);
// It is still worth asserting the marker is complete.
// 4: blr xzr
DCHECK(!result || (instr->following()->IsBranchAndLinkToRegister() &&
instr->following()->Rn() == kZeroRegCode));
return result;
}
int Assembler::ConstantPoolSizeAt(Instruction* instr) {
#ifdef USE_SIMULATOR
// Assembler::debug() embeds constants directly into the instruction stream.
// Although this is not a genuine constant pool, treat it like one to avoid
// disassembling the constants.
if ((instr->Mask(ExceptionMask) == HLT) &&
(instr->ImmException() == kImmExceptionIsDebug)) {
const char* message =
reinterpret_cast<const char*>(
instr->InstructionAtOffset(kDebugMessageOffset));
int size = static_cast<int>(kDebugMessageOffset + strlen(message) + 1);
return RoundUp(size, kInstructionSize) / kInstructionSize;
}
// Same for printf support, see MacroAssembler::CallPrintf().
if ((instr->Mask(ExceptionMask) == HLT) &&
(instr->ImmException() == kImmExceptionIsPrintf)) {
return kPrintfLength / kInstructionSize;
}
#endif
if (IsConstantPoolAt(instr)) {
return instr->ImmLLiteral();
} else {
return -1;
}
}
void Assembler::EmitPoolGuard() {
// We must generate only one instruction as this is used in scopes that
// control the size of the code generated.
Emit(BLR | Rn(xzr));
}
void Assembler::StartBlockVeneerPool() {
++veneer_pool_blocked_nesting_;
}
void Assembler::EndBlockVeneerPool() {
if (--veneer_pool_blocked_nesting_ == 0) {
// Check the veneer pool hasn't been blocked for too long.
DCHECK(unresolved_branches_.empty() ||
(pc_offset() < unresolved_branches_first_limit()));
}
}
void Assembler::br(const Register& xn) {
positions_recorder()->WriteRecordedPositions();
DCHECK(xn.Is64Bits());
Emit(BR | Rn(xn));
}
void Assembler::blr(const Register& xn) {
positions_recorder()->WriteRecordedPositions();
DCHECK(xn.Is64Bits());
// The pattern 'blr xzr' is used as a guard to detect when execution falls
// through the constant pool. It should not be emitted.
DCHECK(!xn.Is(xzr));
Emit(BLR | Rn(xn));
}
void Assembler::ret(const Register& xn) {
positions_recorder()->WriteRecordedPositions();
DCHECK(xn.Is64Bits());
Emit(RET | Rn(xn));
}
void Assembler::b(int imm26) {
Emit(B | ImmUncondBranch(imm26));
}
void Assembler::b(Label* label) {
positions_recorder()->WriteRecordedPositions();
b(LinkAndGetInstructionOffsetTo(label));
}
void Assembler::b(int imm19, Condition cond) {
Emit(B_cond | ImmCondBranch(imm19) | cond);
}
void Assembler::b(Label* label, Condition cond) {
positions_recorder()->WriteRecordedPositions();
b(LinkAndGetInstructionOffsetTo(label), cond);
}
void Assembler::bl(int imm26) {
positions_recorder()->WriteRecordedPositions();
Emit(BL | ImmUncondBranch(imm26));
}
void Assembler::bl(Label* label) {
positions_recorder()->WriteRecordedPositions();
bl(LinkAndGetInstructionOffsetTo(label));
}
void Assembler::cbz(const Register& rt,
int imm19) {
positions_recorder()->WriteRecordedPositions();
Emit(SF(rt) | CBZ | ImmCmpBranch(imm19) | Rt(rt));
}
void Assembler::cbz(const Register& rt,
Label* label) {
positions_recorder()->WriteRecordedPositions();
cbz(rt, LinkAndGetInstructionOffsetTo(label));
}
void Assembler::cbnz(const Register& rt,
int imm19) {
positions_recorder()->WriteRecordedPositions();
Emit(SF(rt) | CBNZ | ImmCmpBranch(imm19) | Rt(rt));
}
void Assembler::cbnz(const Register& rt,
Label* label) {
positions_recorder()->WriteRecordedPositions();
cbnz(rt, LinkAndGetInstructionOffsetTo(label));
}
void Assembler::tbz(const Register& rt,
unsigned bit_pos,
int imm14) {
positions_recorder()->WriteRecordedPositions();
DCHECK(rt.Is64Bits() || (rt.Is32Bits() && (bit_pos < kWRegSizeInBits)));
Emit(TBZ | ImmTestBranchBit(bit_pos) | ImmTestBranch(imm14) | Rt(rt));
}
void Assembler::tbz(const Register& rt,
unsigned bit_pos,
Label* label) {
positions_recorder()->WriteRecordedPositions();
tbz(rt, bit_pos, LinkAndGetInstructionOffsetTo(label));
}
void Assembler::tbnz(const Register& rt,
unsigned bit_pos,
int imm14) {
positions_recorder()->WriteRecordedPositions();
DCHECK(rt.Is64Bits() || (rt.Is32Bits() && (bit_pos < kWRegSizeInBits)));
Emit(TBNZ | ImmTestBranchBit(bit_pos) | ImmTestBranch(imm14) | Rt(rt));
}
void Assembler::tbnz(const Register& rt,
unsigned bit_pos,
Label* label) {
positions_recorder()->WriteRecordedPositions();
tbnz(rt, bit_pos, LinkAndGetInstructionOffsetTo(label));
}
void Assembler::adr(const Register& rd, int imm21) {
DCHECK(rd.Is64Bits());
Emit(ADR | ImmPCRelAddress(imm21) | Rd(rd));
}
void Assembler::adr(const Register& rd, Label* label) {
adr(rd, LinkAndGetByteOffsetTo(label));
}
void Assembler::add(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSub(rd, rn, operand, LeaveFlags, ADD);
}
void Assembler::adds(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSub(rd, rn, operand, SetFlags, ADD);
}
void Assembler::cmn(const Register& rn,
const Operand& operand) {
Register zr = AppropriateZeroRegFor(rn);
adds(zr, rn, operand);
}
void Assembler::sub(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSub(rd, rn, operand, LeaveFlags, SUB);
}
void Assembler::subs(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSub(rd, rn, operand, SetFlags, SUB);
}
void Assembler::cmp(const Register& rn, const Operand& operand) {
Register zr = AppropriateZeroRegFor(rn);
subs(zr, rn, operand);
}
void Assembler::neg(const Register& rd, const Operand& operand) {
Register zr = AppropriateZeroRegFor(rd);
sub(rd, zr, operand);
}
void Assembler::negs(const Register& rd, const Operand& operand) {
Register zr = AppropriateZeroRegFor(rd);
subs(rd, zr, operand);
}
void Assembler::adc(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSubWithCarry(rd, rn, operand, LeaveFlags, ADC);
}
void Assembler::adcs(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSubWithCarry(rd, rn, operand, SetFlags, ADC);
}
void Assembler::sbc(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSubWithCarry(rd, rn, operand, LeaveFlags, SBC);
}
void Assembler::sbcs(const Register& rd,
const Register& rn,
const Operand& operand) {
AddSubWithCarry(rd, rn, operand, SetFlags, SBC);
}
void Assembler::ngc(const Register& rd, const Operand& operand) {
Register zr = AppropriateZeroRegFor(rd);
sbc(rd, zr, operand);
}
void Assembler::ngcs(const Register& rd, const Operand& operand) {
Register zr = AppropriateZeroRegFor(rd);
sbcs(rd, zr, operand);
}
// Logical instructions.
void Assembler::and_(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, AND);
}
void Assembler::ands(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, ANDS);
}
void Assembler::tst(const Register& rn,
const Operand& operand) {
ands(AppropriateZeroRegFor(rn), rn, operand);
}
void Assembler::bic(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, BIC);
}
void Assembler::bics(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, BICS);
}
void Assembler::orr(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, ORR);
}
void Assembler::orn(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, ORN);
}
void Assembler::eor(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, EOR);
}
void Assembler::eon(const Register& rd,
const Register& rn,
const Operand& operand) {
Logical(rd, rn, operand, EON);
}
void Assembler::lslv(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | LSLV | Rm(rm) | Rn(rn) | Rd(rd));
}
void Assembler::lsrv(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | LSRV | Rm(rm) | Rn(rn) | Rd(rd));
}
void Assembler::asrv(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | ASRV | Rm(rm) | Rn(rn) | Rd(rd));
}
void Assembler::rorv(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | RORV | Rm(rm) | Rn(rn) | Rd(rd));
}
// Bitfield operations.
void Assembler::bfm(const Register& rd, const Register& rn, int immr,
int imms) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
Instr N = SF(rd) >> (kSFOffset - kBitfieldNOffset);
Emit(SF(rd) | BFM | N |
ImmR(immr, rd.SizeInBits()) |
ImmS(imms, rn.SizeInBits()) |
Rn(rn) | Rd(rd));
}
void Assembler::sbfm(const Register& rd, const Register& rn, int immr,
int imms) {
DCHECK(rd.Is64Bits() || rn.Is32Bits());
Instr N = SF(rd) >> (kSFOffset - kBitfieldNOffset);
Emit(SF(rd) | SBFM | N |
ImmR(immr, rd.SizeInBits()) |
ImmS(imms, rn.SizeInBits()) |
Rn(rn) | Rd(rd));
}
void Assembler::ubfm(const Register& rd, const Register& rn, int immr,
int imms) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
Instr N = SF(rd) >> (kSFOffset - kBitfieldNOffset);
Emit(SF(rd) | UBFM | N |
ImmR(immr, rd.SizeInBits()) |
ImmS(imms, rn.SizeInBits()) |
Rn(rn) | Rd(rd));
}
void Assembler::extr(const Register& rd, const Register& rn, const Register& rm,
int lsb) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Instr N = SF(rd) >> (kSFOffset - kBitfieldNOffset);
Emit(SF(rd) | EXTR | N | Rm(rm) |
ImmS(lsb, rn.SizeInBits()) | Rn(rn) | Rd(rd));
}
void Assembler::csel(const Register& rd,
const Register& rn,
const Register& rm,
Condition cond) {
ConditionalSelect(rd, rn, rm, cond, CSEL);
}
void Assembler::csinc(const Register& rd,
const Register& rn,
const Register& rm,
Condition cond) {
ConditionalSelect(rd, rn, rm, cond, CSINC);
}
void Assembler::csinv(const Register& rd,
const Register& rn,
const Register& rm,
Condition cond) {
ConditionalSelect(rd, rn, rm, cond, CSINV);
}
void Assembler::csneg(const Register& rd,
const Register& rn,
const Register& rm,
Condition cond) {
ConditionalSelect(rd, rn, rm, cond, CSNEG);
}
void Assembler::cset(const Register &rd, Condition cond) {
DCHECK((cond != al) && (cond != nv));
Register zr = AppropriateZeroRegFor(rd);
csinc(rd, zr, zr, NegateCondition(cond));
}
void Assembler::csetm(const Register &rd, Condition cond) {
DCHECK((cond != al) && (cond != nv));
Register zr = AppropriateZeroRegFor(rd);
csinv(rd, zr, zr, NegateCondition(cond));
}
void Assembler::cinc(const Register &rd, const Register &rn, Condition cond) {
DCHECK((cond != al) && (cond != nv));
csinc(rd, rn, rn, NegateCondition(cond));
}
void Assembler::cinv(const Register &rd, const Register &rn, Condition cond) {
DCHECK((cond != al) && (cond != nv));
csinv(rd, rn, rn, NegateCondition(cond));
}
void Assembler::cneg(const Register &rd, const Register &rn, Condition cond) {
DCHECK((cond != al) && (cond != nv));
csneg(rd, rn, rn, NegateCondition(cond));
}
void Assembler::ConditionalSelect(const Register& rd,
const Register& rn,
const Register& rm,
Condition cond,
ConditionalSelectOp op) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | op | Rm(rm) | Cond(cond) | Rn(rn) | Rd(rd));
}
void Assembler::ccmn(const Register& rn,
const Operand& operand,
StatusFlags nzcv,
Condition cond) {
ConditionalCompare(rn, operand, nzcv, cond, CCMN);
}
void Assembler::ccmp(const Register& rn,
const Operand& operand,
StatusFlags nzcv,
Condition cond) {
ConditionalCompare(rn, operand, nzcv, cond, CCMP);
}
void Assembler::DataProcessing3Source(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra,
DataProcessing3SourceOp op) {
Emit(SF(rd) | op | Rm(rm) | Ra(ra) | Rn(rn) | Rd(rd));
}
void Assembler::mul(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(AreSameSizeAndType(rd, rn, rm));
Register zr = AppropriateZeroRegFor(rn);
DataProcessing3Source(rd, rn, rm, zr, MADD);
}
void Assembler::madd(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra) {
DCHECK(AreSameSizeAndType(rd, rn, rm, ra));
DataProcessing3Source(rd, rn, rm, ra, MADD);
}
void Assembler::mneg(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(AreSameSizeAndType(rd, rn, rm));
Register zr = AppropriateZeroRegFor(rn);
DataProcessing3Source(rd, rn, rm, zr, MSUB);
}
void Assembler::msub(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra) {
DCHECK(AreSameSizeAndType(rd, rn, rm, ra));
DataProcessing3Source(rd, rn, rm, ra, MSUB);
}
void Assembler::smaddl(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra) {
DCHECK(rd.Is64Bits() && ra.Is64Bits());
DCHECK(rn.Is32Bits() && rm.Is32Bits());
DataProcessing3Source(rd, rn, rm, ra, SMADDL_x);
}
void Assembler::smsubl(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra) {
DCHECK(rd.Is64Bits() && ra.Is64Bits());
DCHECK(rn.Is32Bits() && rm.Is32Bits());
DataProcessing3Source(rd, rn, rm, ra, SMSUBL_x);
}
void Assembler::umaddl(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra) {
DCHECK(rd.Is64Bits() && ra.Is64Bits());
DCHECK(rn.Is32Bits() && rm.Is32Bits());
DataProcessing3Source(rd, rn, rm, ra, UMADDL_x);
}
void Assembler::umsubl(const Register& rd,
const Register& rn,
const Register& rm,
const Register& ra) {
DCHECK(rd.Is64Bits() && ra.Is64Bits());
DCHECK(rn.Is32Bits() && rm.Is32Bits());
DataProcessing3Source(rd, rn, rm, ra, UMSUBL_x);
}
void Assembler::smull(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.Is64Bits());
DCHECK(rn.Is32Bits() && rm.Is32Bits());
DataProcessing3Source(rd, rn, rm, xzr, SMADDL_x);
}
void Assembler::smulh(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(AreSameSizeAndType(rd, rn, rm));
DataProcessing3Source(rd, rn, rm, xzr, SMULH_x);
}
void Assembler::sdiv(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | SDIV | Rm(rm) | Rn(rn) | Rd(rd));
}
void Assembler::udiv(const Register& rd,
const Register& rn,
const Register& rm) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == rm.SizeInBits());
Emit(SF(rd) | UDIV | Rm(rm) | Rn(rn) | Rd(rd));
}
void Assembler::rbit(const Register& rd,
const Register& rn) {
DataProcessing1Source(rd, rn, RBIT);
}
void Assembler::rev16(const Register& rd,
const Register& rn) {
DataProcessing1Source(rd, rn, REV16);
}
void Assembler::rev32(const Register& rd,
const Register& rn) {
DCHECK(rd.Is64Bits());
DataProcessing1Source(rd, rn, REV);
}
void Assembler::rev(const Register& rd,
const Register& rn) {
DataProcessing1Source(rd, rn, rd.Is64Bits() ? REV_x : REV_w);
}
void Assembler::clz(const Register& rd,
const Register& rn) {
DataProcessing1Source(rd, rn, CLZ);
}
void Assembler::cls(const Register& rd,
const Register& rn) {
DataProcessing1Source(rd, rn, CLS);
}
void Assembler::ldp(const CPURegister& rt,
const CPURegister& rt2,
const MemOperand& src) {
LoadStorePair(rt, rt2, src, LoadPairOpFor(rt, rt2));
}
void Assembler::stp(const CPURegister& rt,
const CPURegister& rt2,
const MemOperand& dst) {
LoadStorePair(rt, rt2, dst, StorePairOpFor(rt, rt2));
}
void Assembler::ldpsw(const Register& rt,
const Register& rt2,
const MemOperand& src) {
DCHECK(rt.Is64Bits());
LoadStorePair(rt, rt2, src, LDPSW_x);
}
void Assembler::LoadStorePair(const CPURegister& rt,
const CPURegister& rt2,
const MemOperand& addr,
LoadStorePairOp op) {
// 'rt' and 'rt2' can only be aliased for stores.
DCHECK(((op & LoadStorePairLBit) == 0) || !rt.Is(rt2));
DCHECK(AreSameSizeAndType(rt, rt2));
DCHECK(IsImmLSPair(addr.offset(), CalcLSPairDataSize(op)));
int offset = static_cast<int>(addr.offset());
Instr memop = op | Rt(rt) | Rt2(rt2) | RnSP(addr.base()) |
ImmLSPair(offset, CalcLSPairDataSize(op));
Instr addrmodeop;
if (addr.IsImmediateOffset()) {
addrmodeop = LoadStorePairOffsetFixed;
} else {
// Pre-index and post-index modes.
DCHECK(!rt.Is(addr.base()));
DCHECK(!rt2.Is(addr.base()));
DCHECK(addr.offset() != 0);
if (addr.IsPreIndex()) {
addrmodeop = LoadStorePairPreIndexFixed;
} else {
DCHECK(addr.IsPostIndex());
addrmodeop = LoadStorePairPostIndexFixed;
}
}
Emit(addrmodeop | memop);
}
// Memory instructions.
void Assembler::ldrb(const Register& rt, const MemOperand& src) {
LoadStore(rt, src, LDRB_w);
}
void Assembler::strb(const Register& rt, const MemOperand& dst) {
LoadStore(rt, dst, STRB_w);
}
void Assembler::ldrsb(const Register& rt, const MemOperand& src) {
LoadStore(rt, src, rt.Is64Bits() ? LDRSB_x : LDRSB_w);
}
void Assembler::ldrh(const Register& rt, const MemOperand& src) {
LoadStore(rt, src, LDRH_w);
}
void Assembler::strh(const Register& rt, const MemOperand& dst) {
LoadStore(rt, dst, STRH_w);
}
void Assembler::ldrsh(const Register& rt, const MemOperand& src) {
LoadStore(rt, src, rt.Is64Bits() ? LDRSH_x : LDRSH_w);
}
void Assembler::ldr(const CPURegister& rt, const MemOperand& src) {
LoadStore(rt, src, LoadOpFor(rt));
}
void Assembler::str(const CPURegister& rt, const MemOperand& src) {
LoadStore(rt, src, StoreOpFor(rt));
}
void Assembler::ldrsw(const Register& rt, const MemOperand& src) {
DCHECK(rt.Is64Bits());
LoadStore(rt, src, LDRSW_x);
}
void Assembler::ldr_pcrel(const CPURegister& rt, int imm19) {
// The pattern 'ldr xzr, #offset' is used to indicate the beginning of a
// constant pool. It should not be emitted.
DCHECK(!rt.IsZero());
Emit(LoadLiteralOpFor(rt) | ImmLLiteral(imm19) | Rt(rt));
}
void Assembler::ldr(const CPURegister& rt, const Immediate& imm) {
// Currently we only support 64-bit literals.
DCHECK(rt.Is64Bits());
RecordRelocInfo(imm.rmode(), imm.value());
BlockConstPoolFor(1);
// The load will be patched when the constpool is emitted, patching code
// expect a load literal with offset 0.
ldr_pcrel(rt, 0);
}
void Assembler::mov(const Register& rd, const Register& rm) {
// Moves involving the stack pointer are encoded as add immediate with
// second operand of zero. Otherwise, orr with first operand zr is
// used.
if (rd.IsSP() || rm.IsSP()) {
add(rd, rm, 0);
} else {
orr(rd, AppropriateZeroRegFor(rd), rm);
}
}
void Assembler::mvn(const Register& rd, const Operand& operand) {
orn(rd, AppropriateZeroRegFor(rd), operand);
}
void Assembler::mrs(const Register& rt, SystemRegister sysreg) {
DCHECK(rt.Is64Bits());
Emit(MRS | ImmSystemRegister(sysreg) | Rt(rt));
}
void Assembler::msr(SystemRegister sysreg, const Register& rt) {
DCHECK(rt.Is64Bits());
Emit(MSR | Rt(rt) | ImmSystemRegister(sysreg));
}
void Assembler::hint(SystemHint code) {
Emit(HINT | ImmHint(code) | Rt(xzr));
}
void Assembler::dmb(BarrierDomain domain, BarrierType type) {
Emit(DMB | ImmBarrierDomain(domain) | ImmBarrierType(type));
}
void Assembler::dsb(BarrierDomain domain, BarrierType type) {
Emit(DSB | ImmBarrierDomain(domain) | ImmBarrierType(type));
}
void Assembler::isb() {
Emit(ISB | ImmBarrierDomain(FullSystem) | ImmBarrierType(BarrierAll));
}
void Assembler::fmov(FPRegister fd, double imm) {
DCHECK(fd.Is64Bits());
DCHECK(IsImmFP64(imm));
Emit(FMOV_d_imm | Rd(fd) | ImmFP64(imm));
}
void Assembler::fmov(FPRegister fd, float imm) {
DCHECK(fd.Is32Bits());
DCHECK(IsImmFP32(imm));
Emit(FMOV_s_imm | Rd(fd) | ImmFP32(imm));
}
void Assembler::fmov(Register rd, FPRegister fn) {
DCHECK(rd.SizeInBits() == fn.SizeInBits());
FPIntegerConvertOp op = rd.Is32Bits() ? FMOV_ws : FMOV_xd;
Emit(op | Rd(rd) | Rn(fn));
}
void Assembler::fmov(FPRegister fd, Register rn) {
DCHECK(fd.SizeInBits() == rn.SizeInBits());
FPIntegerConvertOp op = fd.Is32Bits() ? FMOV_sw : FMOV_dx;
Emit(op | Rd(fd) | Rn(rn));
}
void Assembler::fmov(FPRegister fd, FPRegister fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
Emit(FPType(fd) | FMOV | Rd(fd) | Rn(fn));
}
void Assembler::fadd(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FADD);
}
void Assembler::fsub(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FSUB);
}
void Assembler::fmul(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FMUL);
}
void Assembler::fmadd(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
const FPRegister& fa) {
FPDataProcessing3Source(fd, fn, fm, fa, fd.Is32Bits() ? FMADD_s : FMADD_d);
}
void Assembler::fmsub(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
const FPRegister& fa) {
FPDataProcessing3Source(fd, fn, fm, fa, fd.Is32Bits() ? FMSUB_s : FMSUB_d);
}
void Assembler::fnmadd(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
const FPRegister& fa) {
FPDataProcessing3Source(fd, fn, fm, fa, fd.Is32Bits() ? FNMADD_s : FNMADD_d);
}
void Assembler::fnmsub(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
const FPRegister& fa) {
FPDataProcessing3Source(fd, fn, fm, fa, fd.Is32Bits() ? FNMSUB_s : FNMSUB_d);
}
void Assembler::fdiv(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FDIV);
}
void Assembler::fmax(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FMAX);
}
void Assembler::fmaxnm(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FMAXNM);
}
void Assembler::fmin(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FMIN);
}
void Assembler::fminnm(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm) {
FPDataProcessing2Source(fd, fn, fm, FMINNM);
}
void Assembler::fabs(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FABS);
}
void Assembler::fneg(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FNEG);
}
void Assembler::fsqrt(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FSQRT);
}
void Assembler::frinta(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FRINTA);
}
void Assembler::frintm(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FRINTM);
}
void Assembler::frintn(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FRINTN);
}
void Assembler::frintp(const FPRegister& fd, const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FRINTP);
}
void Assembler::frintz(const FPRegister& fd,
const FPRegister& fn) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
FPDataProcessing1Source(fd, fn, FRINTZ);
}
void Assembler::fcmp(const FPRegister& fn,
const FPRegister& fm) {
DCHECK(fn.SizeInBits() == fm.SizeInBits());
Emit(FPType(fn) | FCMP | Rm(fm) | Rn(fn));
}
void Assembler::fcmp(const FPRegister& fn,
double value) {
USE(value);
// Although the fcmp instruction can strictly only take an immediate value of
// +0.0, we don't need to check for -0.0 because the sign of 0.0 doesn't
// affect the result of the comparison.
DCHECK(value == 0.0);
Emit(FPType(fn) | FCMP_zero | Rn(fn));
}
void Assembler::fccmp(const FPRegister& fn,
const FPRegister& fm,
StatusFlags nzcv,
Condition cond) {
DCHECK(fn.SizeInBits() == fm.SizeInBits());
Emit(FPType(fn) | FCCMP | Rm(fm) | Cond(cond) | Rn(fn) | Nzcv(nzcv));
}
void Assembler::fcsel(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
Condition cond) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
DCHECK(fd.SizeInBits() == fm.SizeInBits());
Emit(FPType(fd) | FCSEL | Rm(fm) | Cond(cond) | Rn(fn) | Rd(fd));
}
void Assembler::FPConvertToInt(const Register& rd,
const FPRegister& fn,
FPIntegerConvertOp op) {
Emit(SF(rd) | FPType(fn) | op | Rn(fn) | Rd(rd));
}
void Assembler::fcvt(const FPRegister& fd,
const FPRegister& fn) {
if (fd.Is64Bits()) {
// Convert float to double.
DCHECK(fn.Is32Bits());
FPDataProcessing1Source(fd, fn, FCVT_ds);
} else {
// Convert double to float.
DCHECK(fn.Is64Bits());
FPDataProcessing1Source(fd, fn, FCVT_sd);
}
}
void Assembler::fcvtau(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTAU);
}
void Assembler::fcvtas(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTAS);
}
void Assembler::fcvtmu(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTMU);
}
void Assembler::fcvtms(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTMS);
}
void Assembler::fcvtnu(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTNU);
}
void Assembler::fcvtns(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTNS);
}
void Assembler::fcvtzu(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTZU);
}
void Assembler::fcvtzs(const Register& rd, const FPRegister& fn) {
FPConvertToInt(rd, fn, FCVTZS);
}
void Assembler::scvtf(const FPRegister& fd,
const Register& rn,
unsigned fbits) {
if (fbits == 0) {
Emit(SF(rn) | FPType(fd) | SCVTF | Rn(rn) | Rd(fd));
} else {
Emit(SF(rn) | FPType(fd) | SCVTF_fixed | FPScale(64 - fbits) | Rn(rn) |
Rd(fd));
}
}
void Assembler::ucvtf(const FPRegister& fd,
const Register& rn,
unsigned fbits) {
if (fbits == 0) {
Emit(SF(rn) | FPType(fd) | UCVTF | Rn(rn) | Rd(fd));
} else {
Emit(SF(rn) | FPType(fd) | UCVTF_fixed | FPScale(64 - fbits) | Rn(rn) |
Rd(fd));
}
}
void Assembler::dcptr(Label* label) {
RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
if (label->is_bound()) {
// The label is bound, so it does not need to be updated and the internal
// reference should be emitted.
//
// In this case, label->pos() returns the offset of the label from the
// start of the buffer.
internal_reference_positions_.push_back(pc_offset());
dc64(reinterpret_cast<uintptr_t>(buffer_ + label->pos()));
} else {
int32_t offset;
if (label->is_linked()) {
// The label is linked, so the internal reference should be added
// onto the end of the label's link chain.
//
// In this case, label->pos() returns the offset of the last linked
// instruction from the start of the buffer.
offset = label->pos() - pc_offset();
DCHECK(offset != kStartOfLabelLinkChain);
} else {
// The label is unused, so it now becomes linked and the internal
// reference is at the start of the new link chain.
offset = kStartOfLabelLinkChain;
}
// The instruction at pc is now the last link in the label's chain.
label->link_to(pc_offset());
// Traditionally the offset to the previous instruction in the chain is
// encoded in the instruction payload (e.g. branch range) but internal
// references are not instructions so while unbound they are encoded as
// two consecutive brk instructions. The two 16-bit immediates are used
// to encode the offset.
offset >>= kInstructionSizeLog2;
DCHECK(is_int32(offset));
uint32_t high16 = unsigned_bitextract_32(31, 16, offset);
uint32_t low16 = unsigned_bitextract_32(15, 0, offset);
brk(high16);
brk(low16);
}
}
// Note:
// Below, a difference in case for the same letter indicates a
// negated bit.
// If b is 1, then B is 0.
Instr Assembler::ImmFP32(float imm) {
DCHECK(IsImmFP32(imm));
// bits: aBbb.bbbc.defg.h000.0000.0000.0000.0000
uint32_t bits = float_to_rawbits(imm);
// bit7: a000.0000
uint32_t bit7 = ((bits >> 31) & 0x1) << 7;
// bit6: 0b00.0000
uint32_t bit6 = ((bits >> 29) & 0x1) << 6;
// bit5_to_0: 00cd.efgh
uint32_t bit5_to_0 = (bits >> 19) & 0x3f;
return (bit7 | bit6 | bit5_to_0) << ImmFP_offset;
}
Instr Assembler::ImmFP64(double imm) {
DCHECK(IsImmFP64(imm));
// bits: aBbb.bbbb.bbcd.efgh.0000.0000.0000.0000
// 0000.0000.0000.0000.0000.0000.0000.0000
uint64_t bits = double_to_rawbits(imm);
// bit7: a000.0000
uint64_t bit7 = ((bits >> 63) & 0x1) << 7;
// bit6: 0b00.0000
uint64_t bit6 = ((bits >> 61) & 0x1) << 6;
// bit5_to_0: 00cd.efgh
uint64_t bit5_to_0 = (bits >> 48) & 0x3f;
return static_cast<Instr>((bit7 | bit6 | bit5_to_0) << ImmFP_offset);
}
// Code generation helpers.
void Assembler::MoveWide(const Register& rd,
uint64_t imm,
int shift,
MoveWideImmediateOp mov_op) {
// 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 zero (a positive 32-bit number) or top
// 33 bits are one (a negative 32-bit number, sign extended to 64 bits).
DCHECK(((imm >> kWRegSizeInBits) == 0) ||
((imm >> (kWRegSizeInBits - 1)) == 0x1ffffffff));
imm &= kWRegMask;
}
if (shift >= 0) {
// Explicit shift specified.
DCHECK((shift == 0) || (shift == 16) || (shift == 32) || (shift == 48));
DCHECK(rd.Is64Bits() || (shift == 0) || (shift == 16));
shift /= 16;
} else {
// Calculate a new immediate and shift combination to encode the immediate
// argument.
shift = 0;
if ((imm & ~0xffffUL) == 0) {
// Nothing to do.
} else if ((imm & ~(0xffffUL << 16)) == 0) {
imm >>= 16;
shift = 1;
} else if ((imm & ~(0xffffUL << 32)) == 0) {
DCHECK(rd.Is64Bits());
imm >>= 32;
shift = 2;
} else if ((imm & ~(0xffffUL << 48)) == 0) {
DCHECK(rd.Is64Bits());
imm >>= 48;
shift = 3;
}
}
DCHECK(is_uint16(imm));
Emit(SF(rd) | MoveWideImmediateFixed | mov_op | Rd(rd) |
ImmMoveWide(static_cast<int>(imm)) | ShiftMoveWide(shift));
}
void Assembler::AddSub(const Register& rd,
const Register& rn,
const Operand& operand,
FlagsUpdate S,
AddSubOp op) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(!operand.NeedsRelocation(this));
if (operand.IsImmediate()) {
int64_t immediate = operand.ImmediateValue();
DCHECK(IsImmAddSub(immediate));
Instr dest_reg = (S == SetFlags) ? Rd(rd) : RdSP(rd);
Emit(SF(rd) | AddSubImmediateFixed | op | Flags(S) |
ImmAddSub(static_cast<int>(immediate)) | dest_reg | RnSP(rn));
} else if (operand.IsShiftedRegister()) {
DCHECK(operand.reg().SizeInBits() == rd.SizeInBits());
DCHECK(operand.shift() != ROR);
// For instructions of the form:
// add/sub wsp, <Wn>, <Wm> [, LSL #0-3 ]
// add/sub <Wd>, wsp, <Wm> [, LSL #0-3 ]
// add/sub wsp, wsp, <Wm> [, LSL #0-3 ]
// adds/subs <Wd>, wsp, <Wm> [, LSL #0-3 ]
// or their 64-bit register equivalents, convert the operand from shifted to
// extended register mode, and emit an add/sub extended instruction.
if (rn.IsSP() || rd.IsSP()) {
DCHECK(!(rd.IsSP() && (S == SetFlags)));
DataProcExtendedRegister(rd, rn, operand.ToExtendedRegister(), S,
AddSubExtendedFixed | op);
} else {
DataProcShiftedRegister(rd, rn, operand, S, AddSubShiftedFixed | op);
}
} else {
DCHECK(operand.IsExtendedRegister());
DataProcExtendedRegister(rd, rn, operand, S, AddSubExtendedFixed | op);
}
}
void Assembler::AddSubWithCarry(const Register& rd,
const Register& rn,
const Operand& operand,
FlagsUpdate S,
AddSubWithCarryOp op) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(rd.SizeInBits() == operand.reg().SizeInBits());
DCHECK(operand.IsShiftedRegister() && (operand.shift_amount() == 0));
DCHECK(!operand.NeedsRelocation(this));
Emit(SF(rd) | op | Flags(S) | Rm(operand.reg()) | Rn(rn) | Rd(rd));
}
void Assembler::hlt(int code) {
DCHECK(is_uint16(code));
Emit(HLT | ImmException(code));
}
void Assembler::brk(int code) {
DCHECK(is_uint16(code));
Emit(BRK | ImmException(code));
}
void Assembler::EmitStringData(const char* string) {
size_t len = strlen(string) + 1;
DCHECK(RoundUp(len, kInstructionSize) <= static_cast<size_t>(kGap));
EmitData(string, static_cast<int>(len));
// Pad with NULL characters until pc_ is aligned.
const char pad[] = {'\0', '\0', '\0', '\0'};
STATIC_ASSERT(sizeof(pad) == kInstructionSize);
EmitData(pad, RoundUp(pc_offset(), kInstructionSize) - pc_offset());
}
void Assembler::debug(const char* message, uint32_t code, Instr params) {
#ifdef USE_SIMULATOR
// Don't generate simulator specific code if we are building a snapshot, which
// might be run on real hardware.
if (!serializer_enabled()) {
// The arguments to the debug marker need to be contiguous in memory, so
// make sure we don't try to emit pools.
BlockPoolsScope scope(this);
Label start;
bind(&start);
// Refer to instructions-arm64.h for a description of the marker and its
// arguments.
hlt(kImmExceptionIsDebug);
DCHECK(SizeOfCodeGeneratedSince(&start) == kDebugCodeOffset);
dc32(code);
DCHECK(SizeOfCodeGeneratedSince(&start) == kDebugParamsOffset);
dc32(params);
DCHECK(SizeOfCodeGeneratedSince(&start) == kDebugMessageOffset);
EmitStringData(message);
hlt(kImmExceptionIsUnreachable);
return;
}
// Fall through if Serializer is enabled.
#endif
if (params & BREAK) {
hlt(kImmExceptionIsDebug);
}
}
void Assembler::Logical(const Register& rd,
const Register& rn,
const Operand& operand,
LogicalOp op) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
DCHECK(!operand.NeedsRelocation(this));
if (operand.IsImmediate()) {
int64_t immediate = operand.ImmediateValue();
unsigned reg_size = rd.SizeInBits();
DCHECK(immediate != 0);
DCHECK(immediate != -1);
DCHECK(rd.Is64Bits() || is_uint32(immediate));
// If the operation is NOT, invert the operation and immediate.
if ((op & NOT) == NOT) {
op = static_cast<LogicalOp>(op & ~NOT);
immediate = rd.Is64Bits() ? ~immediate : (~immediate & kWRegMask);
}
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 {
// This case is handled in the macro assembler.
UNREACHABLE();
}
} else {
DCHECK(operand.IsShiftedRegister());
DCHECK(operand.reg().SizeInBits() == rd.SizeInBits());
Instr dp_op = static_cast<Instr>(op | LogicalShiftedFixed);
DataProcShiftedRegister(rd, rn, operand, LeaveFlags, dp_op);
}
}
void Assembler::LogicalImmediate(const Register& rd,
const Register& rn,
unsigned n,
unsigned imm_s,
unsigned imm_r,
LogicalOp op) {
unsigned reg_size = rd.SizeInBits();
Instr dest_reg = (op == ANDS) ? Rd(rd) : RdSP(rd);
Emit(SF(rd) | LogicalImmediateFixed | op | BitN(n, reg_size) |
ImmSetBits(imm_s, reg_size) | ImmRotate(imm_r, reg_size) | dest_reg |
Rn(rn));
}
void Assembler::ConditionalCompare(const Register& rn,
const Operand& operand,
StatusFlags nzcv,
Condition cond,
ConditionalCompareOp op) {
Instr ccmpop;
DCHECK(!operand.NeedsRelocation(this));
if (operand.IsImmediate()) {
int64_t immediate = operand.ImmediateValue();
DCHECK(IsImmConditionalCompare(immediate));
ccmpop = ConditionalCompareImmediateFixed | op |
ImmCondCmp(static_cast<unsigned>(immediate));
} else {
DCHECK(operand.IsShiftedRegister() && (operand.shift_amount() == 0));
ccmpop = ConditionalCompareRegisterFixed | op | Rm(operand.reg());
}
Emit(SF(rn) | ccmpop | Cond(cond) | Rn(rn) | Nzcv(nzcv));
}
void Assembler::DataProcessing1Source(const Register& rd,
const Register& rn,
DataProcessing1SourceOp op) {
DCHECK(rd.SizeInBits() == rn.SizeInBits());
Emit(SF(rn) | op | Rn(rn) | Rd(rd));
}
void Assembler::FPDataProcessing1Source(const FPRegister& fd,
const FPRegister& fn,
FPDataProcessing1SourceOp op) {
Emit(FPType(fn) | op | Rn(fn) | Rd(fd));
}
void Assembler::FPDataProcessing2Source(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
FPDataProcessing2SourceOp op) {
DCHECK(fd.SizeInBits() == fn.SizeInBits());
DCHECK(fd.SizeInBits() == fm.SizeInBits());
Emit(FPType(fd) | op | Rm(fm) | Rn(fn) | Rd(fd));
}
void Assembler::FPDataProcessing3Source(const FPRegister& fd,
const FPRegister& fn,
const FPRegister& fm,
const FPRegister& fa,
FPDataProcessing3SourceOp op) {
DCHECK(AreSameSizeAndType(fd, fn, fm, fa));
Emit(FPType(fd) | op | Rm(fm) | Rn(fn) | Rd(fd) | Ra(fa));
}
void Assembler::EmitShift(const Register& rd,
const Register& rn,
Shift shift,
unsigned shift_amount) {
switch (shift) {
case LSL:
lsl(rd, rn, shift_amount);
break;
case LSR:
lsr(rd, rn, shift_amount);
break;
case ASR:
asr(rd, rn, shift_amount);
break;
case ROR:
ror(rd, rn, shift_amount);
break;
default:
UNREACHABLE();
}
}
void Assembler::EmitExtendShift(const Register& rd,
const Register& rn,
Extend extend,
unsigned left_shift) {
DCHECK(rd.SizeInBits() >= rn.SizeInBits());
unsigned reg_size = rd.SizeInBits();
// Use the correct size of register.
Register rn_ = Register::Create(rn.code(), rd.SizeInBits());
// Bits extracted are high_bit:0.
unsigned high_bit = (8 << (extend & 0x3)) - 1;
// Number of bits left in the result that are not introduced by the shift.
unsigned non_shift_bits = (reg_size - left_shift) & (reg_size - 1);
if ((non_shift_bits > high_bit) || (non_shift_bits == 0)) {
switch (extend) {
case UXTB:
case UXTH:
case UXTW: ubfm(rd, rn_, non_shift_bits, high_bit); break;
case SXTB:
case SXTH:
case SXTW: sbfm(rd, rn_, non_shift_bits, high_bit); break;
case UXTX:
case SXTX: {
DCHECK(rn.SizeInBits() == kXRegSizeInBits);
// Nothing to extend. Just shift.
lsl(rd, rn_, left_shift);
break;
}
default: UNREACHABLE();
}
} else {
// No need to extend as the extended bits would be shifted away.
lsl(rd, rn_, left_shift);
}
}
void Assembler::DataProcShiftedRegister(const Register& rd,
const Register& rn,
const Operand& operand,
FlagsUpdate S,
Instr op) {
DCHECK(operand.IsShiftedRegister());
DCHECK(rn.Is64Bits() || (rn.Is32Bits() && is_uint5(operand.shift_amount())));
DCHECK(!operand.NeedsRelocation(this));
Emit(SF(rd) | op | Flags(S) |
ShiftDP(operand.shift()) | ImmDPShift(operand.shift_amount()) |
Rm(operand.reg()) | Rn(rn) | Rd(rd));
}
void Assembler::DataProcExtendedRegister(const Register& rd,
const Register& rn,
const Operand& operand,
FlagsUpdate S,
Instr op) {
DCHECK(!operand.NeedsRelocation(this));
Instr dest_reg = (S == SetFlags) ? Rd(rd) : RdSP(rd);
Emit(SF(rd) | op | Flags(S) | Rm(operand.reg()) |
ExtendMode(operand.extend()) | ImmExtendShift(operand.shift_amount()) |
dest_reg | RnSP(rn));
}
bool Assembler::IsImmAddSub(int64_t immediate) {
return is_uint12(immediate) ||
(is_uint12(immediate >> 12) && ((immediate & 0xfff) == 0));
}
void Assembler::LoadStore(const CPURegister& rt,
const MemOperand& addr,
LoadStoreOp op) {
Instr memop = op | Rt(rt) | RnSP(addr.base());
if (addr.IsImmediateOffset()) {
LSDataSize size = CalcLSDataSize(op);
if (IsImmLSScaled(addr.offset(), size)) {
int offset = static_cast<int>(addr.offset());
// Use the scaled addressing mode.
Emit(LoadStoreUnsignedOffsetFixed | memop |
ImmLSUnsigned(offset >> size));
} else if (IsImmLSUnscaled(addr.offset())) {
int offset = static_cast<int>(addr.offset());
// Use the unscaled addressing mode.
Emit(LoadStoreUnscaledOffsetFixed | memop | ImmLS(offset));
} else {
// This case is handled in the macro assembler.
UNREACHABLE();
}
} else if (addr.IsRegisterOffset()) {
Extend ext = addr.extend();
Shift shift = addr.shift();
unsigned shift_amount = addr.shift_amount();
// LSL is encoded in the option field as UXTX.
if (shift == LSL) {
ext = UXTX;
}
// Shifts are encoded in one bit, indicating a left shift by the memory
// access size.
DCHECK((shift_amount == 0) ||
(shift_amount == static_cast<unsigned>(CalcLSDataSize(op))));
Emit(LoadStoreRegisterOffsetFixed | memop | Rm(addr.regoffset()) |
ExtendMode(ext) | ImmShiftLS((shift_amount > 0) ? 1 : 0));
} else {
// Pre-index and post-index modes.
DCHECK(!rt.Is(addr.base()));
if (IsImmLSUnscaled(addr.offset())) {
int offset = static_cast<int>(addr.offset());
if (addr.IsPreIndex()) {
Emit(LoadStorePreIndexFixed | memop | ImmLS(offset));
} else {
DCHECK(addr.IsPostIndex());
Emit(LoadStorePostIndexFixed | memop | ImmLS(offset));
}
} else {
// This case is handled in the macro assembler.
UNREACHABLE();
}
}
}
bool Assembler::IsImmLSUnscaled(int64_t offset) {
return is_int9(offset);
}
bool Assembler::IsImmLSScaled(int64_t offset, LSDataSize size) {
bool offset_is_size_multiple = (((offset >> size) << size) == offset);
return offset_is_size_multiple && is_uint12(offset >> size);
}
bool Assembler::IsImmLSPair(int64_t offset, LSDataSize size) {
bool offset_is_size_multiple = (((offset >> size) << size) == offset);
return offset_is_size_multiple && is_int7(offset >> size);
}
bool Assembler::IsImmLLiteral(int64_t offset) {
int inst_size = static_cast<int>(kInstructionSizeLog2);
bool offset_is_inst_multiple =
(((offset >> inst_size) << inst_size) == offset);
return offset_is_inst_multiple && is_intn(offset, ImmLLiteral_width);
}
// Test if a given value can be encoded in the immediate field of a logical
// instruction.
// If it can be encoded, the function returns true, and values pointed to by n,
// imm_s and imm_r are updated with immediates encoded in the format required
// by the corresponding fields in the logical instruction.
// If it can not be encoded, the function returns false, and the values pointed
// to by n, imm_s and imm_r are undefined.
bool Assembler::IsImmLogical(uint64_t value,
unsigned width,
unsigned* n,
unsigned* imm_s,
unsigned* imm_r) {
DCHECK((n != NULL) && (imm_s != NULL) && (imm_r != NULL));
DCHECK((width == kWRegSizeInBits) || (width == kXRegSizeInBits));
bool negate = false;
// Logical immediates are encoded using parameters n, imm_s and imm_r using
// the following table:
//
// N imms immr size S R
// 1 ssssss rrrrrr 64 UInt(ssssss) UInt(rrrrrr)
// 0 0sssss xrrrrr 32 UInt(sssss) UInt(rrrrr)
// 0 10ssss xxrrrr 16 UInt(ssss) UInt(rrrr)
// 0 110sss xxxrrr 8 UInt(sss) UInt(rrr)
// 0 1110ss xxxxrr 4 UInt(ss) UInt(rr)
// 0 11110s xxxxxr 2 UInt(s) UInt(r)
// (s bits must not be all set)
//
// A pattern is constructed of size bits, where the least significant S+1 bits
// are set. The pattern is rotated right by R, and repeated across a 32 or
// 64-bit value, depending on destination register width.
//
// Put another way: the basic format of a logical immediate is a single
// contiguous stretch of 1 bits, repeated across the whole word at intervals
// given by a power of 2. To identify them quickly, we first locate the
// lowest stretch of 1 bits, then the next 1 bit above that; that combination
// is different for every logical immediate, so it gives us all the
// information we need to identify the only logical immediate that our input
// could be, and then we simply check if that's the value we actually have.
//
// (The rotation parameter does give the possibility of the stretch of 1 bits
// going 'round the end' of the word. To deal with that, we observe that in
// any situation where that happens the bitwise NOT of the value is also a
// valid logical immediate. So we simply invert the input whenever its low bit
// is set, and then we know that the rotated case can't arise.)
if (value & 1) {
// If the low bit is 1, negate the value, and set a flag to remember that we
// did (so that we can adjust the return values appropriately).
negate = true;
value = ~value;
}
if (width == kWRegSizeInBits) {
// To handle 32-bit logical immediates, the very easiest thing is to repeat
// the input value twice to make a 64-bit word. The correct encoding of that
// as a logical immediate will also be the correct encoding of the 32-bit
// value.
// The most-significant 32 bits may not be zero (ie. negate is true) so
// shift the value left before duplicating it.
value <<= kWRegSizeInBits;
value |= value >> kWRegSizeInBits;
}
// The basic analysis idea: imagine our input word looks like this.
//
// 0011111000111110001111100011111000111110001111100011111000111110
// c b a
// |<--d-->|
//
// We find the lowest set bit (as an actual power-of-2 value, not its index)
// and call it a. Then we add a to our original number, which wipes out the
// bottommost stretch of set bits and replaces it with a 1 carried into the
// next zero bit. Then we look for the new lowest set bit, which is in
// position b, and subtract it, so now our number is just like the original
// but with the lowest stretch of set bits completely gone. Now we find the
// lowest set bit again, which is position c in the diagram above. Then we'll
// measure the distance d between bit positions a and c (using CLZ), and that
// tells us that the only valid logical immediate that could possibly be equal
// to this number is the one in which a stretch of bits running from a to just
// below b is replicated every d bits.
uint64_t a = LargestPowerOf2Divisor(value);
uint64_t value_plus_a = value + a;
uint64_t b = LargestPowerOf2Divisor(value_plus_a);
uint64_t value_plus_a_minus_b = value_plus_a - b;
uint64_t c = LargestPowerOf2Divisor(value_plus_a_minus_b);
int d, clz_a, out_n;
uint64_t mask;
if (c != 0) {
// The general case, in which there is more than one stretch of set bits.
// Compute the repeat distance d, and set up a bitmask covering the basic
// unit of repetition (i.e. a word with the bottom d bits set). Also, in all
// of these cases the N bit of the output will be zero.
clz_a = CountLeadingZeros(a, kXRegSizeInBits);
int clz_c = CountLeadingZeros(c, kXRegSizeInBits);
d = clz_a - clz_c;
mask = ((V8_UINT64_C(1) << d) - 1);
out_n = 0;
} else {
// Handle degenerate cases.
//
// If any of those 'find lowest set bit' operations didn't find a set bit at
// all, then the word will have been zero thereafter, so in particular the
// last lowest_set_bit operation will have returned zero. So we can test for
// all the special case conditions in one go by seeing if c is zero.
if (a == 0) {
// The input was zero (or all 1 bits, which will come to here too after we
// inverted it at the start of the function), for which we just return
// false.
return false;
} else {
// Otherwise, if c was zero but a was not, then there's just one stretch
// of set bits in our word, meaning that we have the trivial case of
// d == 64 and only one 'repetition'. Set up all the same variables as in
// the general case above, and set the N bit in the output.
clz_a = CountLeadingZeros(a, kXRegSizeInBits);
d = 64;
mask = ~V8_UINT64_C(0);
out_n = 1;
}
}
// If the repeat period d is not a power of two, it can't be encoded.
if (!IS_POWER_OF_TWO(d)) {
return false;
}
if (((b - a) & ~mask) != 0) {
// If the bit stretch (b - a) does not fit within the mask derived from the
// repeat period, then fail.
return false;
}
// The only possible option is b - a repeated every d bits. Now we're going to
// actually construct the valid logical immediate derived from that
// specification, and see if it equals our original input.
//
// To repeat a value every d bits, we multiply it by a number of the form
// (1 + 2^d + 2^(2d) + ...), i.e. 0x0001000100010001 or similar. These can
// be derived using a table lookup on CLZ(d).
static const uint64_t multipliers[] = {
0x0000000000000001UL,
0x0000000100000001UL,
0x0001000100010001UL,
0x0101010101010101UL,
0x1111111111111111UL,
0x5555555555555555UL,
};
int multiplier_idx = CountLeadingZeros(d, kXRegSizeInBits) - 57;
// Ensure that the index to the multipliers array is within bounds.
DCHECK((multiplier_idx >= 0) &&
(static_cast<size_t>(multiplier_idx) < arraysize(multipliers)));
uint64_t multiplier = multipliers[multiplier_idx];
uint64_t candidate = (b - a) * multiplier;
if (value != candidate) {
// The candidate pattern doesn't match our input value, so fail.
return false;
}
// We have a match! This is a valid logical immediate, so now we have to
// construct the bits and pieces of the instruction encoding that generates
// it.
// Count the set bits in our basic stretch. The special case of clz(0) == -1
// makes the answer come out right for stretches that reach the very top of
// the word (e.g. numbers like 0xffffc00000000000).
int clz_b = (b == 0) ? -1 : CountLeadingZeros(b, kXRegSizeInBits);
int s = clz_a - clz_b;
// Decide how many bits to rotate right by, to put the low bit of that basic
// stretch in position a.
int r;
if (negate) {
// If we inverted the input right at the start of this function, here's
// where we compensate: the number of set bits becomes the number of clear
// bits, and the rotation count is based on position b rather than position
// a (since b is the location of the 'lowest' 1 bit after inversion).
s = d - s;
r = (clz_b + 1) & (d - 1);
} else {
r = (clz_a + 1) & (d - 1);
}
// Now we're done, except for having to encode the S output in such a way that
// it gives both the number of set bits and the length of the repeated
// segment. The s field is encoded like this:
//
// imms size S
// ssssss 64 UInt(ssssss)
// 0sssss 32 UInt(sssss)
// 10ssss 16 UInt(ssss)
// 110sss 8 UInt(sss)
// 1110ss 4 UInt(ss)
// 11110s 2 UInt(s)
//
// So we 'or' (-d << 1) with our computed s to form imms.
*n = out_n;
*imm_s = ((-d << 1) | (s - 1)) & 0x3f;
*imm_r = r;
return true;
}
bool Assembler::IsImmConditionalCompare(int64_t immediate) {
return is_uint5(immediate);
}
bool Assembler::IsImmFP32(float imm) {
// Valid values will have the form:
// aBbb.bbbc.defg.h000.0000.0000.0000.0000
uint32_t bits = float_to_rawbits(imm);
// bits[19..0] are cleared.
if ((bits & 0x7ffff) != 0) {
return false;
}
// bits[29..25] are all set or all cleared.
uint32_t b_pattern = (bits >> 16) & 0x3e00;
if (b_pattern != 0 && b_pattern != 0x3e00) {
return false;
}
// bit[30] and bit[29] are opposite.
if (((bits ^ (bits << 1)) & 0x40000000) == 0) {
return false;
}
return true;
}
bool Assembler::IsImmFP64(double imm) {
// Valid values will have the form:
// aBbb.bbbb.bbcd.efgh.0000.0000.0000.0000
// 0000.0000.0000.0000.0000.0000.0000.0000
uint64_t bits = double_to_rawbits(imm);
// bits[47..0] are cleared.
if ((bits & 0xffffffffffffL) != 0) {
return false;
}
// bits[61..54] are all set or all cleared.
uint32_t b_pattern = (bits >> 48) & 0x3fc0;
if (b_pattern != 0 && b_pattern != 0x3fc0) {
return false;
}
// bit[62] and bit[61] are opposite.
if (((bits ^ (bits << 1)) & 0x4000000000000000L) == 0) {
return false;
}
return true;
}
void Assembler::GrowBuffer() {
if (!own_buffer_) FATAL("external code buffer is too small");
// Compute new buffer size.
CodeDesc desc; // the new buffer
if (buffer_size_ < 1 * MB) {
desc.buffer_size = 2 * buffer_size_;
} else {
desc.buffer_size = buffer_size_ + 1 * MB;
}
CHECK_GT(desc.buffer_size, 0); // No overflow.
byte* buffer = reinterpret_cast<byte*>(buffer_);
// Set up new buffer.
desc.buffer = NewArray<byte>(desc.buffer_size);
desc.origin = this;
desc.instr_size = pc_offset();
desc.reloc_size =
static_cast<int>((buffer + buffer_size_) - reloc_info_writer.pos());
// Copy the data.
intptr_t pc_delta = desc.buffer - buffer;
intptr_t rc_delta = (desc.buffer + desc.buffer_size) -
(buffer + buffer_size_);
memmove(desc.buffer, buffer, desc.instr_size);
memmove(reloc_info_writer.pos() + rc_delta,
reloc_info_writer.pos(), desc.reloc_size);
// Switch buffers.
DeleteArray(buffer_);
buffer_ = desc.buffer;
buffer_size_ = desc.buffer_size;
pc_ = reinterpret_cast<byte*>(pc_) + pc_delta;
reloc_info_writer.Reposition(reloc_info_writer.pos() + rc_delta,
reloc_info_writer.last_pc() + pc_delta);
// None of our relocation types are pc relative pointing outside the code
// buffer nor pc absolute pointing inside the code buffer, so there is no need
// to relocate any emitted relocation entries.
// Relocate internal references.
for (auto pos : internal_reference_positions_) {
intptr_t* p = reinterpret_cast<intptr_t*>(buffer_ + pos);
*p += pc_delta;
}
// Pending relocation entries are also relative, no need to relocate.
}
void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
// We do not try to reuse pool constants.
RelocInfo rinfo(isolate(), reinterpret_cast<byte*>(pc_), rmode, data, NULL);
if (((rmode >= RelocInfo::COMMENT) &&
(rmode <= RelocInfo::DEBUG_BREAK_SLOT_AT_TAIL_CALL)) ||
(rmode == RelocInfo::INTERNAL_REFERENCE) ||
(rmode == RelocInfo::CONST_POOL) || (rmode == RelocInfo::VENEER_POOL) ||
(rmode == RelocInfo::DEOPT_REASON) ||
(rmode == RelocInfo::GENERATOR_CONTINUATION)) {
// Adjust code for new modes.
DCHECK(RelocInfo::IsDebugBreakSlot(rmode) || RelocInfo::IsComment(rmode) ||
RelocInfo::IsDeoptReason(rmode) || RelocInfo::IsPosition(rmode) ||
RelocInfo::IsInternalReference(rmode) ||
RelocInfo::IsConstPool(rmode) || RelocInfo::IsVeneerPool(rmode) ||
RelocInfo::IsGeneratorContinuation(rmode));
// These modes do not need an entry in the constant pool.
} else {
constpool_.RecordEntry(data, rmode);
// Make sure the constant pool is not emitted in place of the next
// instruction for which we just recorded relocation info.
BlockConstPoolFor(1);
}
if (!RelocInfo::IsNone(rmode)) {
// Don't record external references unless the heap will be serialized.
if (rmode == RelocInfo::EXTERNAL_REFERENCE &&
!serializer_enabled() && !emit_debug_code()) {
return;
}
DCHECK(buffer_space() >= kMaxRelocSize); // too late to grow buffer here
if (rmode == RelocInfo::CODE_TARGET_WITH_ID) {
RelocInfo reloc_info_with_ast_id(isolate(), reinterpret_cast<byte*>(pc_),
rmode, RecordedAstId().ToInt(), NULL);
ClearRecordedAstId();
reloc_info_writer.Write(&reloc_info_with_ast_id);
} else {
reloc_info_writer.Write(&rinfo);
}
}
}
void Assembler::BlockConstPoolFor(int instructions) {
int pc_limit = pc_offset() + instructions * kInstructionSize;
if (no_const_pool_before_ < pc_limit) {
no_const_pool_before_ = pc_limit;
// Make sure the pool won't be blocked for too long.
DCHECK(pc_limit < constpool_.MaxPcOffset());
}
if (next_constant_pool_check_ < no_const_pool_before_) {
next_constant_pool_check_ = no_const_pool_before_;
}
}
void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
// Some short sequence of instruction mustn't be broken up by constant pool
// emission, such sequences are protected by calls to BlockConstPoolFor and
// BlockConstPoolScope.
if (is_const_pool_blocked()) {
// Something is wrong if emission is forced and blocked at the same time.
DCHECK(!force_emit);
return;
}
// There is nothing to do if there are no pending constant pool entries.
if (constpool_.IsEmpty()) {
// Calculate the offset of the next check.
SetNextConstPoolCheckIn(kCheckConstPoolInterval);
return;
}
// We emit a constant pool when:
// * requested to do so by parameter force_emit (e.g. after each function).
// * the distance to the first instruction accessing the constant pool is
// kApproxMaxDistToConstPool or more.
// * the number of entries in the pool is kApproxMaxPoolEntryCount or more.
int dist = constpool_.DistanceToFirstUse();
int count = constpool_.EntryCount();
if (!force_emit &&
(dist < kApproxMaxDistToConstPool) &&
(count < kApproxMaxPoolEntryCount)) {
return;
}
// Emit veneers for branches that would go out of range during emission of the
// constant pool.
int worst_case_size = constpool_.WorstCaseSize();
CheckVeneerPool(false, require_jump,
kVeneerDistanceMargin + worst_case_size);
// Check that the code buffer is large enough before emitting the constant
// pool (this includes the gap to the relocation information).
int needed_space = worst_case_size + kGap + 1 * kInstructionSize;
while (buffer_space() <= needed_space) {
GrowBuffer();
}
Label size_check;
bind(&size_check);
constpool_.Emit(require_jump);
DCHECK(SizeOfCodeGeneratedSince(&size_check) <=
static_cast<unsigned>(worst_case_size));
// Since a constant pool was just emitted, move the check offset forward by
// the standard interval.
SetNextConstPoolCheckIn(kCheckConstPoolInterval);
}
bool Assembler::ShouldEmitVeneer(int max_reachable_pc, int margin) {
// Account for the branch around the veneers and the guard.
int protection_offset = 2 * kInstructionSize;
return pc_offset() > max_reachable_pc - margin - protection_offset -
static_cast<int>(unresolved_branches_.size() * kMaxVeneerCodeSize);
}
void Assembler::RecordVeneerPool(int location_offset, int size) {
RelocInfo rinfo(isolate(), buffer_ + location_offset, RelocInfo::VENEER_POOL,
static_cast<intptr_t>(size), NULL);
reloc_info_writer.Write(&rinfo);
}
void Assembler::EmitVeneers(bool force_emit, bool need_protection, int margin) {
BlockPoolsScope scope(this);
RecordComment("[ Veneers");
// The exact size of the veneer pool must be recorded (see the comment at the
// declaration site of RecordConstPool()), but computing the number of
// veneers that will be generated is not obvious. So instead we remember the
// current position and will record the size after the pool has been
// generated.
Label size_check;
bind(&size_check);
int veneer_pool_relocinfo_loc = pc_offset();
Label end;
if (need_protection) {
b(&end);
}
EmitVeneersGuard();
Label veneer_size_check;
std::multimap<int, FarBranchInfo>::iterator it, it_to_delete;
it = unresolved_branches_.begin();
while (it != unresolved_branches_.end()) {
if (force_emit || ShouldEmitVeneer(it->first, margin)) {
Instruction* branch = InstructionAt(it->second.pc_offset_);
Label* label = it->second.label_;
#ifdef DEBUG
bind(&veneer_size_check);
#endif
// Patch the branch to point to the current position, and emit a branch
// to the label.
Instruction* veneer = reinterpret_cast<Instruction*>(pc_);
RemoveBranchFromLabelLinkChain(branch, label, veneer);
branch->SetImmPCOffsetTarget(isolate(), veneer);
b(label);
#ifdef DEBUG
DCHECK(SizeOfCodeGeneratedSince(&veneer_size_check) <=
static_cast<uint64_t>(kMaxVeneerCodeSize));
veneer_size_check.Unuse();
#endif
it_to_delete = it++;
unresolved_branches_.erase(it_to_delete);
} else {
++it;
}
}
// Record the veneer pool size.
int pool_size = static_cast<int>(SizeOfCodeGeneratedSince(&size_check));
RecordVeneerPool(veneer_pool_relocinfo_loc, pool_size);
if (unresolved_branches_.empty()) {
next_veneer_pool_check_ = kMaxInt;
} else {
next_veneer_pool_check_ =
unresolved_branches_first_limit() - kVeneerDistanceCheckMargin;
}
bind(&end);
RecordComment("]");
}
void Assembler::CheckVeneerPool(bool force_emit, bool require_jump,
int margin) {
// There is nothing to do if there are no pending veneer pool entries.
if (unresolved_branches_.empty()) {
DCHECK(next_veneer_pool_check_ == kMaxInt);
return;
}
DCHECK(pc_offset() < unresolved_branches_first_limit());
// Some short sequence of instruction mustn't be broken up by veneer pool
// emission, such sequences are protected by calls to BlockVeneerPoolFor and
// BlockVeneerPoolScope.
if (is_veneer_pool_blocked()) {
DCHECK(!force_emit);
return;
}
if (!require_jump) {
// Prefer emitting veneers protected by an existing instruction.
margin *= kVeneerNoProtectionFactor;
}
if (force_emit || ShouldEmitVeneers(margin)) {
EmitVeneers(force_emit, require_jump, margin);
} else {
next_veneer_pool_check_ =
unresolved_branches_first_limit() - kVeneerDistanceCheckMargin;
}
}
int Assembler::buffer_space() const {
return static_cast<int>(reloc_info_writer.pos() -
reinterpret_cast<byte*>(pc_));
}
void Assembler::RecordConstPool(int size) {
// We only need this for debugger support, to correctly compute offsets in the
// code.
RecordRelocInfo(RelocInfo::CONST_POOL, static_cast<intptr_t>(size));
}
void PatchingAssembler::PatchAdrFar(int64_t target_offset) {
// The code at the current instruction should be:
// adr rd, 0
// nop (adr_far)
// nop (adr_far)
// movz scratch, 0
// Verify the expected code.
Instruction* expected_adr = InstructionAt(0);
CHECK(expected_adr->IsAdr() && (expected_adr->ImmPCRel() == 0));
int rd_code = expected_adr->Rd();
for (int i = 0; i < kAdrFarPatchableNNops; ++i) {
CHECK(InstructionAt((i + 1) * kInstructionSize)->IsNop(ADR_FAR_NOP));
}
Instruction* expected_movz =
InstructionAt((kAdrFarPatchableNInstrs - 1) * kInstructionSize);
CHECK(expected_movz->IsMovz() &&
(expected_movz->ImmMoveWide() == 0) &&
(expected_movz->ShiftMoveWide() == 0));
int scratch_code = expected_movz->Rd();
// Patch to load the correct address.
Register rd = Register::XRegFromCode(rd_code);
Register scratch = Register::XRegFromCode(scratch_code);
// Addresses are only 48 bits.
adr(rd, target_offset & 0xFFFF);
movz(scratch, (target_offset >> 16) & 0xFFFF, 16);
movk(scratch, (target_offset >> 32) & 0xFFFF, 32);
DCHECK((target_offset >> 48) == 0);
add(rd, rd, scratch);
}
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_ARM64