/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <type_traits>
#include "assembler_thumb2.h"
#include "base/bit_utils.h"
#include "base/logging.h"
#include "entrypoints/quick/quick_entrypoints.h"
#include "offsets.h"
#include "thread.h"
namespace art {
namespace arm {
template <typename Function>
void Thumb2Assembler::Fixup::ForExpandableDependencies(Thumb2Assembler* assembler, Function fn) {
static_assert(
std::is_same<typename std::result_of<Function(FixupId, FixupId)>::type, void>::value,
"Incorrect signature for argument `fn`: expected (FixupId, FixupId) -> void");
Fixup* fixups = assembler->fixups_.data();
for (FixupId fixup_id = 0u, end_id = assembler->fixups_.size(); fixup_id != end_id; ++fixup_id) {
uint32_t target = fixups[fixup_id].target_;
if (target > fixups[fixup_id].location_) {
for (FixupId id = fixup_id + 1u; id != end_id && fixups[id].location_ < target; ++id) {
if (fixups[id].CanExpand()) {
fn(id, fixup_id);
}
}
} else {
for (FixupId id = fixup_id; id != 0u && fixups[id - 1u].location_ >= target; --id) {
if (fixups[id - 1u].CanExpand()) {
fn(id - 1u, fixup_id);
}
}
}
}
}
void Thumb2Assembler::Fixup::PrepareDependents(Thumb2Assembler* assembler) {
// For each Fixup, it's easy to find the Fixups that it depends on as they are either
// the following or the preceding Fixups until we find the target. However, for fixup
// adjustment we need the reverse lookup, i.e. what Fixups depend on a given Fixup.
// This function creates a compact representation of this relationship, where we have
// all the dependents in a single array and Fixups reference their ranges by start
// index and count. (Instead of having a per-fixup vector.)
// Count the number of dependents of each Fixup.
Fixup* fixups = assembler->fixups_.data();
ForExpandableDependencies(
assembler,
[fixups](FixupId dependency, FixupId dependent ATTRIBUTE_UNUSED) {
fixups[dependency].dependents_count_ += 1u;
});
// Assign index ranges in fixup_dependents_ to individual fixups. Record the end of the
// range in dependents_start_, we shall later decrement it as we fill in fixup_dependents_.
uint32_t number_of_dependents = 0u;
for (FixupId fixup_id = 0u, end_id = assembler->fixups_.size(); fixup_id != end_id; ++fixup_id) {
number_of_dependents += fixups[fixup_id].dependents_count_;
fixups[fixup_id].dependents_start_ = number_of_dependents;
}
if (number_of_dependents == 0u) {
return;
}
// Create and fill in the fixup_dependents_.
assembler->fixup_dependents_.resize(number_of_dependents);
FixupId* dependents = assembler->fixup_dependents_.data();
ForExpandableDependencies(
assembler,
[fixups, dependents](FixupId dependency, FixupId dependent) {
fixups[dependency].dependents_start_ -= 1u;
dependents[fixups[dependency].dependents_start_] = dependent;
});
}
void Thumb2Assembler::BindLabel(Label* label, uint32_t bound_pc) {
CHECK(!label->IsBound());
while (label->IsLinked()) {
FixupId fixup_id = label->Position(); // The id for linked Fixup.
Fixup* fixup = GetFixup(fixup_id); // Get the Fixup at this id.
fixup->Resolve(bound_pc); // Fixup can be resolved now.
uint32_t fixup_location = fixup->GetLocation();
uint16_t next = buffer_.Load<uint16_t>(fixup_location); // Get next in chain.
buffer_.Store<int16_t>(fixup_location, 0);
label->position_ = next; // Move to next.
}
label->BindTo(bound_pc);
}
uint32_t Thumb2Assembler::BindLiterals() {
// We don't add the padding here, that's done only after adjusting the Fixup sizes.
uint32_t code_size = buffer_.Size();
for (Literal& lit : literals_) {
Label* label = lit.GetLabel();
BindLabel(label, code_size);
code_size += lit.GetSize();
}
return code_size;
}
void Thumb2Assembler::BindJumpTables(uint32_t code_size) {
for (JumpTable& table : jump_tables_) {
Label* label = table.GetLabel();
BindLabel(label, code_size);
code_size += table.GetSize();
}
}
void Thumb2Assembler::AdjustFixupIfNeeded(Fixup* fixup, uint32_t* current_code_size,
std::deque<FixupId>* fixups_to_recalculate) {
uint32_t adjustment = fixup->AdjustSizeIfNeeded(*current_code_size);
if (adjustment != 0u) {
DCHECK(fixup->CanExpand());
*current_code_size += adjustment;
for (FixupId dependent_id : fixup->Dependents(*this)) {
Fixup* dependent = GetFixup(dependent_id);
dependent->IncreaseAdjustment(adjustment);
if (buffer_.Load<int16_t>(dependent->GetLocation()) == 0) {
buffer_.Store<int16_t>(dependent->GetLocation(), 1);
fixups_to_recalculate->push_back(dependent_id);
}
}
}
}
uint32_t Thumb2Assembler::AdjustFixups() {
Fixup::PrepareDependents(this);
uint32_t current_code_size = buffer_.Size();
std::deque<FixupId> fixups_to_recalculate;
if (kIsDebugBuild) {
// We will use the placeholders in the buffer_ to mark whether the fixup has
// been added to the fixups_to_recalculate. Make sure we start with zeros.
for (Fixup& fixup : fixups_) {
CHECK_EQ(buffer_.Load<int16_t>(fixup.GetLocation()), 0);
}
}
for (Fixup& fixup : fixups_) {
AdjustFixupIfNeeded(&fixup, ¤t_code_size, &fixups_to_recalculate);
}
while (!fixups_to_recalculate.empty()) {
do {
// Pop the fixup.
FixupId fixup_id = fixups_to_recalculate.front();
fixups_to_recalculate.pop_front();
Fixup* fixup = GetFixup(fixup_id);
DCHECK_NE(buffer_.Load<int16_t>(fixup->GetLocation()), 0);
buffer_.Store<int16_t>(fixup->GetLocation(), 0);
// See if it needs adjustment.
AdjustFixupIfNeeded(fixup, ¤t_code_size, &fixups_to_recalculate);
} while (!fixups_to_recalculate.empty());
if ((current_code_size & 2) != 0 && (!literals_.empty() || !jump_tables_.empty())) {
// If we need to add padding before literals, this may just push some out of range,
// so recalculate all load literals. This makes up for the fact that we don't mark
// load literal as a dependency of all previous Fixups even though it actually is.
for (Fixup& fixup : fixups_) {
if (fixup.IsLoadLiteral()) {
AdjustFixupIfNeeded(&fixup, ¤t_code_size, &fixups_to_recalculate);
}
}
}
}
if (kIsDebugBuild) {
// Check that no fixup is marked as being in fixups_to_recalculate anymore.
for (Fixup& fixup : fixups_) {
CHECK_EQ(buffer_.Load<int16_t>(fixup.GetLocation()), 0);
}
}
// Adjust literal pool labels for padding.
DCHECK_ALIGNED(current_code_size, 2);
uint32_t literals_adjustment = current_code_size + (current_code_size & 2) - buffer_.Size();
if (literals_adjustment != 0u) {
for (Literal& literal : literals_) {
Label* label = literal.GetLabel();
DCHECK(label->IsBound());
int old_position = label->Position();
label->Reinitialize();
label->BindTo(old_position + literals_adjustment);
}
for (JumpTable& table : jump_tables_) {
Label* label = table.GetLabel();
DCHECK(label->IsBound());
int old_position = label->Position();
label->Reinitialize();
label->BindTo(old_position + literals_adjustment);
}
}
return current_code_size;
}
void Thumb2Assembler::EmitFixups(uint32_t adjusted_code_size) {
// Move non-fixup code to its final place and emit fixups.
// Process fixups in reverse order so that we don't repeatedly move the same data.
size_t src_end = buffer_.Size();
size_t dest_end = adjusted_code_size;
buffer_.Resize(dest_end);
DCHECK_GE(dest_end, src_end);
for (auto i = fixups_.rbegin(), end = fixups_.rend(); i != end; ++i) {
Fixup* fixup = &*i;
if (fixup->GetOriginalSize() == fixup->GetSize()) {
// The size of this Fixup didn't change. To avoid moving the data
// in small chunks, emit the code to its original position.
fixup->Emit(&buffer_, adjusted_code_size);
fixup->Finalize(dest_end - src_end);
} else {
// Move the data between the end of the fixup and src_end to its final location.
size_t old_fixup_location = fixup->GetLocation();
size_t src_begin = old_fixup_location + fixup->GetOriginalSizeInBytes();
size_t data_size = src_end - src_begin;
size_t dest_begin = dest_end - data_size;
buffer_.Move(dest_begin, src_begin, data_size);
src_end = old_fixup_location;
dest_end = dest_begin - fixup->GetSizeInBytes();
// Finalize the Fixup and emit the data to the new location.
fixup->Finalize(dest_end - src_end);
fixup->Emit(&buffer_, adjusted_code_size);
}
}
CHECK_EQ(src_end, dest_end);
}
void Thumb2Assembler::EmitLiterals() {
if (!literals_.empty()) {
// Load literal instructions (LDR, LDRD, VLDR) require 4-byte alignment.
// We don't support byte and half-word literals.
uint32_t code_size = buffer_.Size();
DCHECK_ALIGNED(code_size, 2);
if ((code_size & 2u) != 0u) {
Emit16(0);
}
for (Literal& literal : literals_) {
AssemblerBuffer::EnsureCapacity ensured(&buffer_);
DCHECK_EQ(static_cast<size_t>(literal.GetLabel()->Position()), buffer_.Size());
DCHECK(literal.GetSize() == 4u || literal.GetSize() == 8u);
for (size_t i = 0, size = literal.GetSize(); i != size; ++i) {
buffer_.Emit<uint8_t>(literal.GetData()[i]);
}
}
}
}
void Thumb2Assembler::EmitJumpTables() {
if (!jump_tables_.empty()) {
// Jump tables require 4 byte alignment. (We don't support byte and half-word jump tables.)
uint32_t code_size = buffer_.Size();
DCHECK_ALIGNED(code_size, 2);
if ((code_size & 2u) != 0u) {
Emit16(0);
}
for (JumpTable& table : jump_tables_) {
// Bulk ensure capacity, as this may be large.
size_t orig_size = buffer_.Size();
size_t required_capacity = orig_size + table.GetSize();
if (required_capacity > buffer_.Capacity()) {
buffer_.ExtendCapacity(required_capacity);
}
#ifndef NDEBUG
buffer_.has_ensured_capacity_ = true;
#endif
DCHECK_EQ(static_cast<size_t>(table.GetLabel()->Position()), buffer_.Size());
int32_t anchor_position = table.GetAnchorLabel()->Position() + 4;
for (Label* target : table.GetData()) {
// Ensure that the label was tracked, so that it will have the right position.
DCHECK(std::find(tracked_labels_.begin(), tracked_labels_.end(), target) !=
tracked_labels_.end());
int32_t offset = target->Position() - anchor_position;
buffer_.Emit<int32_t>(offset);
}
#ifndef NDEBUG
buffer_.has_ensured_capacity_ = false;
#endif
size_t new_size = buffer_.Size();
DCHECK_LE(new_size - orig_size, table.GetSize());
}
}
}
void Thumb2Assembler::PatchCFI() {
if (cfi().NumberOfDelayedAdvancePCs() == 0u) {
return;
}
typedef DebugFrameOpCodeWriterForAssembler::DelayedAdvancePC DelayedAdvancePC;
const auto data = cfi().ReleaseStreamAndPrepareForDelayedAdvancePC();
const std::vector<uint8_t>& old_stream = data.first;
const std::vector<DelayedAdvancePC>& advances = data.second;
// Refill our data buffer with patched opcodes.
cfi().ReserveCFIStream(old_stream.size() + advances.size() + 16);
size_t stream_pos = 0;
for (const DelayedAdvancePC& advance : advances) {
DCHECK_GE(advance.stream_pos, stream_pos);
// Copy old data up to the point where advance was issued.
cfi().AppendRawData(old_stream, stream_pos, advance.stream_pos);
stream_pos = advance.stream_pos;
// Insert the advance command with its final offset.
size_t final_pc = GetAdjustedPosition(advance.pc);
cfi().AdvancePC(final_pc);
}
// Copy the final segment if any.
cfi().AppendRawData(old_stream, stream_pos, old_stream.size());
}
inline int16_t Thumb2Assembler::BEncoding16(int32_t offset, Condition cond) {
DCHECK_ALIGNED(offset, 2);
int16_t encoding = B15 | B14;
if (cond != AL) {
DCHECK(IsInt<9>(offset));
encoding |= B12 | (static_cast<int32_t>(cond) << 8) | ((offset >> 1) & 0xff);
} else {
DCHECK(IsInt<12>(offset));
encoding |= B13 | ((offset >> 1) & 0x7ff);
}
return encoding;
}
inline int32_t Thumb2Assembler::BEncoding32(int32_t offset, Condition cond) {
DCHECK_ALIGNED(offset, 2);
int32_t s = (offset >> 31) & 1; // Sign bit.
int32_t encoding = B31 | B30 | B29 | B28 | B15 |
(s << 26) | // Sign bit goes to bit 26.
((offset >> 1) & 0x7ff); // imm11 goes to bits 0-10.
if (cond != AL) {
DCHECK(IsInt<21>(offset));
// Encode cond, move imm6 from bits 12-17 to bits 16-21 and move J1 and J2.
encoding |= (static_cast<int32_t>(cond) << 22) | ((offset & 0x3f000) << (16 - 12)) |
((offset & (1 << 19)) >> (19 - 13)) | // Extract J1 from bit 19 to bit 13.
((offset & (1 << 18)) >> (18 - 11)); // Extract J2 from bit 18 to bit 11.
} else {
DCHECK(IsInt<25>(offset));
int32_t j1 = ((offset >> 23) ^ s ^ 1) & 1; // Calculate J1 from I1 extracted from bit 23.
int32_t j2 = ((offset >> 22)^ s ^ 1) & 1; // Calculate J2 from I2 extracted from bit 22.
// Move imm10 from bits 12-21 to bits 16-25 and add J1 and J2.
encoding |= B12 | ((offset & 0x3ff000) << (16 - 12)) |
(j1 << 13) | (j2 << 11);
}
return encoding;
}
inline int16_t Thumb2Assembler::CbxzEncoding16(Register rn, int32_t offset, Condition cond) {
DCHECK(!IsHighRegister(rn));
DCHECK_ALIGNED(offset, 2);
DCHECK(IsUint<7>(offset));
DCHECK(cond == EQ || cond == NE);
return B15 | B13 | B12 | B8 | (cond == NE ? B11 : 0) | static_cast<int32_t>(rn) |
((offset & 0x3e) << (3 - 1)) | // Move imm5 from bits 1-5 to bits 3-7.
((offset & 0x40) << (9 - 6)); // Move i from bit 6 to bit 11
}
inline int16_t Thumb2Assembler::CmpRnImm8Encoding16(Register rn, int32_t value) {
DCHECK(!IsHighRegister(rn));
DCHECK(IsUint<8>(value));
return B13 | B11 | (rn << 8) | value;
}
inline int16_t Thumb2Assembler::AddRdnRmEncoding16(Register rdn, Register rm) {
// The high bit of rn is moved across 4-bit rm.
return B14 | B10 | (static_cast<int32_t>(rm) << 3) |
(static_cast<int32_t>(rdn) & 7) | ((static_cast<int32_t>(rdn) & 8) << 4);
}
inline int32_t Thumb2Assembler::MovwEncoding32(Register rd, int32_t value) {
DCHECK(IsUint<16>(value));
return B31 | B30 | B29 | B28 | B25 | B22 |
(static_cast<int32_t>(rd) << 8) |
((value & 0xf000) << (16 - 12)) | // Move imm4 from bits 12-15 to bits 16-19.
((value & 0x0800) << (26 - 11)) | // Move i from bit 11 to bit 26.
((value & 0x0700) << (12 - 8)) | // Move imm3 from bits 8-10 to bits 12-14.
(value & 0xff); // Keep imm8 in bits 0-7.
}
inline int32_t Thumb2Assembler::MovtEncoding32(Register rd, int32_t value) {
DCHECK_EQ(value & 0xffff, 0);
int32_t movw_encoding = MovwEncoding32(rd, (value >> 16) & 0xffff);
return movw_encoding | B25 | B23;
}
inline int32_t Thumb2Assembler::MovModImmEncoding32(Register rd, int32_t value) {
uint32_t mod_imm = ModifiedImmediate(value);
DCHECK_NE(mod_imm, kInvalidModifiedImmediate);
return B31 | B30 | B29 | B28 | B22 | B19 | B18 | B17 | B16 |
(static_cast<int32_t>(rd) << 8) | static_cast<int32_t>(mod_imm);
}
inline int16_t Thumb2Assembler::LdrLitEncoding16(Register rt, int32_t offset) {
DCHECK(!IsHighRegister(rt));
DCHECK_ALIGNED(offset, 4);
DCHECK(IsUint<10>(offset));
return B14 | B11 | (static_cast<int32_t>(rt) << 8) | (offset >> 2);
}
inline int32_t Thumb2Assembler::LdrLitEncoding32(Register rt, int32_t offset) {
// NOTE: We don't support negative offset, i.e. U=0 (B23).
return LdrRtRnImm12Encoding(rt, PC, offset);
}
inline int32_t Thumb2Assembler::LdrdEncoding32(Register rt, Register rt2, Register rn, int32_t offset) {
DCHECK_ALIGNED(offset, 4);
CHECK(IsUint<10>(offset));
return B31 | B30 | B29 | B27 |
B24 /* P = 1 */ | B23 /* U = 1 */ | B22 | 0 /* W = 0 */ | B20 |
(static_cast<int32_t>(rn) << 16) | (static_cast<int32_t>(rt) << 12) |
(static_cast<int32_t>(rt2) << 8) | (offset >> 2);
}
inline int32_t Thumb2Assembler::VldrsEncoding32(SRegister sd, Register rn, int32_t offset) {
DCHECK_ALIGNED(offset, 4);
CHECK(IsUint<10>(offset));
return B31 | B30 | B29 | B27 | B26 | B24 |
B23 /* U = 1 */ | B20 | B11 | B9 |
(static_cast<int32_t>(rn) << 16) |
((static_cast<int32_t>(sd) & 0x01) << (22 - 0)) | // Move D from bit 0 to bit 22.
((static_cast<int32_t>(sd) & 0x1e) << (12 - 1)) | // Move Vd from bits 1-4 to bits 12-15.
(offset >> 2);
}
inline int32_t Thumb2Assembler::VldrdEncoding32(DRegister dd, Register rn, int32_t offset) {
DCHECK_ALIGNED(offset, 4);
CHECK(IsUint<10>(offset));
return B31 | B30 | B29 | B27 | B26 | B24 |
B23 /* U = 1 */ | B20 | B11 | B9 | B8 |
(rn << 16) |
((static_cast<int32_t>(dd) & 0x10) << (22 - 4)) | // Move D from bit 4 to bit 22.
((static_cast<int32_t>(dd) & 0x0f) << (12 - 0)) | // Move Vd from bits 0-3 to bits 12-15.
(offset >> 2);
}
inline int16_t Thumb2Assembler::LdrRtRnImm5Encoding16(Register rt, Register rn, int32_t offset) {
DCHECK(!IsHighRegister(rt));
DCHECK(!IsHighRegister(rn));
DCHECK_ALIGNED(offset, 4);
DCHECK(IsUint<7>(offset));
return B14 | B13 | B11 |
(static_cast<int32_t>(rn) << 3) | static_cast<int32_t>(rt) |
(offset << (6 - 2)); // Move imm5 from bits 2-6 to bits 6-10.
}
int32_t Thumb2Assembler::Fixup::LoadWideOrFpEncoding(Register rbase, int32_t offset) const {
switch (type_) {
case kLoadLiteralWide:
return LdrdEncoding32(rn_, rt2_, rbase, offset);
case kLoadFPLiteralSingle:
return VldrsEncoding32(sd_, rbase, offset);
case kLoadFPLiteralDouble:
return VldrdEncoding32(dd_, rbase, offset);
default:
LOG(FATAL) << "Unexpected type: " << static_cast<int>(type_);
UNREACHABLE();
}
}
inline int32_t Thumb2Assembler::LdrRtRnImm12Encoding(Register rt, Register rn, int32_t offset) {
DCHECK(IsUint<12>(offset));
return B31 | B30 | B29 | B28 | B27 | B23 | B22 | B20 | (rn << 16) | (rt << 12) | offset;
}
inline int16_t Thumb2Assembler::AdrEncoding16(Register rd, int32_t offset) {
DCHECK(IsUint<10>(offset));
DCHECK(IsAligned<4>(offset));
DCHECK(!IsHighRegister(rd));
return B15 | B13 | (rd << 8) | (offset >> 2);
}
inline int32_t Thumb2Assembler::AdrEncoding32(Register rd, int32_t offset) {
DCHECK(IsUint<12>(offset));
// Bit 26: offset[11]
// Bits 14-12: offset[10-8]
// Bits 7-0: offset[7-0]
int32_t immediate_mask =
((offset & (1 << 11)) << (26 - 11)) |
((offset & (7 << 8)) << (12 - 8)) |
(offset & 0xFF);
return B31 | B30 | B29 | B28 | B25 | B19 | B18 | B17 | B16 | (rd << 8) | immediate_mask;
}
void Thumb2Assembler::FinalizeCode() {
ArmAssembler::FinalizeCode();
uint32_t size_after_literals = BindLiterals();
BindJumpTables(size_after_literals);
uint32_t adjusted_code_size = AdjustFixups();
EmitFixups(adjusted_code_size);
EmitLiterals();
FinalizeTrackedLabels();
EmitJumpTables();
PatchCFI();
}
bool Thumb2Assembler::ShifterOperandCanAlwaysHold(uint32_t immediate) {
return ArmAssembler::ModifiedImmediate(immediate) != kInvalidModifiedImmediate;
}
bool Thumb2Assembler::ShifterOperandCanHold(Register rd ATTRIBUTE_UNUSED,
Register rn ATTRIBUTE_UNUSED,
Opcode opcode,
uint32_t immediate,
SetCc set_cc,
ShifterOperand* shifter_op) {
shifter_op->type_ = ShifterOperand::kImmediate;
shifter_op->immed_ = immediate;
shifter_op->is_shift_ = false;
shifter_op->is_rotate_ = false;
switch (opcode) {
case ADD:
case SUB:
// Less than (or equal to) 12 bits can be done if we don't need to set condition codes.
if (immediate < (1 << 12) && set_cc != kCcSet) {
return true;
}
return ArmAssembler::ModifiedImmediate(immediate) != kInvalidModifiedImmediate;
case MOV:
// TODO: Support less than or equal to 12bits.
return ArmAssembler::ModifiedImmediate(immediate) != kInvalidModifiedImmediate;
case MVN:
default:
return ArmAssembler::ModifiedImmediate(immediate) != kInvalidModifiedImmediate;
}
}
void Thumb2Assembler::and_(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, AND, set_cc, rn, rd, so);
}
void Thumb2Assembler::eor(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, EOR, set_cc, rn, rd, so);
}
void Thumb2Assembler::sub(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, SUB, set_cc, rn, rd, so);
}
void Thumb2Assembler::rsb(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, RSB, set_cc, rn, rd, so);
}
void Thumb2Assembler::add(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, ADD, set_cc, rn, rd, so);
}
void Thumb2Assembler::adc(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, ADC, set_cc, rn, rd, so);
}
void Thumb2Assembler::sbc(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, SBC, set_cc, rn, rd, so);
}
void Thumb2Assembler::rsc(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, RSC, set_cc, rn, rd, so);
}
void Thumb2Assembler::tst(Register rn, const ShifterOperand& so, Condition cond) {
CHECK_NE(rn, PC); // Reserve tst pc instruction for exception handler marker.
EmitDataProcessing(cond, TST, kCcSet, rn, R0, so);
}
void Thumb2Assembler::teq(Register rn, const ShifterOperand& so, Condition cond) {
CHECK_NE(rn, PC); // Reserve teq pc instruction for exception handler marker.
EmitDataProcessing(cond, TEQ, kCcSet, rn, R0, so);
}
void Thumb2Assembler::cmp(Register rn, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, CMP, kCcSet, rn, R0, so);
}
void Thumb2Assembler::cmn(Register rn, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, CMN, kCcSet, rn, R0, so);
}
void Thumb2Assembler::orr(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, ORR, set_cc, rn, rd, so);
}
void Thumb2Assembler::orn(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, ORN, set_cc, rn, rd, so);
}
void Thumb2Assembler::mov(Register rd, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, MOV, set_cc, R0, rd, so);
}
void Thumb2Assembler::bic(Register rd, Register rn, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, BIC, set_cc, rn, rd, so);
}
void Thumb2Assembler::mvn(Register rd, const ShifterOperand& so,
Condition cond, SetCc set_cc) {
EmitDataProcessing(cond, MVN, set_cc, R0, rd, so);
}
void Thumb2Assembler::mul(Register rd, Register rn, Register rm, Condition cond) {
CheckCondition(cond);
if (rd == rm && !IsHighRegister(rd) && !IsHighRegister(rn) && !force_32bit_) {
// 16 bit.
int16_t encoding = B14 | B9 | B8 | B6 |
rn << 3 | rd;
Emit16(encoding);
} else {
// 32 bit.
uint32_t op1 = 0U /* 0b000 */;
uint32_t op2 = 0U /* 0b00 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 |
op1 << 20 |
B15 | B14 | B13 | B12 |
op2 << 4 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
}
void Thumb2Assembler::mla(Register rd, Register rn, Register rm, Register ra,
Condition cond) {
CheckCondition(cond);
uint32_t op1 = 0U /* 0b000 */;
uint32_t op2 = 0U /* 0b00 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 |
op1 << 20 |
op2 << 4 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(ra) << 12 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::mls(Register rd, Register rn, Register rm, Register ra,
Condition cond) {
CheckCondition(cond);
uint32_t op1 = 0U /* 0b000 */;
uint32_t op2 = 01 /* 0b01 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 |
op1 << 20 |
op2 << 4 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(ra) << 12 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::smull(Register rd_lo, Register rd_hi, Register rn,
Register rm, Condition cond) {
CheckCondition(cond);
uint32_t op1 = 0U /* 0b000; */;
uint32_t op2 = 0U /* 0b0000 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 | B23 |
op1 << 20 |
op2 << 4 |
static_cast<uint32_t>(rd_lo) << 12 |
static_cast<uint32_t>(rd_hi) << 8 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::umull(Register rd_lo, Register rd_hi, Register rn,
Register rm, Condition cond) {
CheckCondition(cond);
uint32_t op1 = 2U /* 0b010; */;
uint32_t op2 = 0U /* 0b0000 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 | B23 |
op1 << 20 |
op2 << 4 |
static_cast<uint32_t>(rd_lo) << 12 |
static_cast<uint32_t>(rd_hi) << 8 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::sdiv(Register rd, Register rn, Register rm, Condition cond) {
CheckCondition(cond);
uint32_t op1 = 1U /* 0b001 */;
uint32_t op2 = 15U /* 0b1111 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 | B23 | B20 |
op1 << 20 |
op2 << 4 |
0xf << 12 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::udiv(Register rd, Register rn, Register rm, Condition cond) {
CheckCondition(cond);
uint32_t op1 = 1U /* 0b001 */;
uint32_t op2 = 15U /* 0b1111 */;
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B24 | B23 | B21 | B20 |
op1 << 20 |
op2 << 4 |
0xf << 12 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::sbfx(Register rd, Register rn, uint32_t lsb, uint32_t width, Condition cond) {
CheckCondition(cond);
CHECK_LE(lsb, 31U);
CHECK(1U <= width && width <= 32U) << width;
uint32_t widthminus1 = width - 1;
uint32_t imm2 = lsb & (B1 | B0); // Bits 0-1 of `lsb`.
uint32_t imm3 = (lsb & (B4 | B3 | B2)) >> 2; // Bits 2-4 of `lsb`.
uint32_t op = 20U /* 0b10100 */;
int32_t encoding = B31 | B30 | B29 | B28 | B25 |
op << 20 |
static_cast<uint32_t>(rn) << 16 |
imm3 << 12 |
static_cast<uint32_t>(rd) << 8 |
imm2 << 6 |
widthminus1;
Emit32(encoding);
}
void Thumb2Assembler::ubfx(Register rd, Register rn, uint32_t lsb, uint32_t width, Condition cond) {
CheckCondition(cond);
CHECK_LE(lsb, 31U);
CHECK(1U <= width && width <= 32U) << width;
uint32_t widthminus1 = width - 1;
uint32_t imm2 = lsb & (B1 | B0); // Bits 0-1 of `lsb`.
uint32_t imm3 = (lsb & (B4 | B3 | B2)) >> 2; // Bits 2-4 of `lsb`.
uint32_t op = 28U /* 0b11100 */;
int32_t encoding = B31 | B30 | B29 | B28 | B25 |
op << 20 |
static_cast<uint32_t>(rn) << 16 |
imm3 << 12 |
static_cast<uint32_t>(rd) << 8 |
imm2 << 6 |
widthminus1;
Emit32(encoding);
}
void Thumb2Assembler::ldr(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, true, false, false, false, rd, ad);
}
void Thumb2Assembler::str(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, false, false, false, false, rd, ad);
}
void Thumb2Assembler::ldrb(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, true, true, false, false, rd, ad);
}
void Thumb2Assembler::strb(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, false, true, false, false, rd, ad);
}
void Thumb2Assembler::ldrh(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, true, false, true, false, rd, ad);
}
void Thumb2Assembler::strh(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, false, false, true, false, rd, ad);
}
void Thumb2Assembler::ldrsb(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, true, true, false, true, rd, ad);
}
void Thumb2Assembler::ldrsh(Register rd, const Address& ad, Condition cond) {
EmitLoadStore(cond, true, false, true, true, rd, ad);
}
void Thumb2Assembler::ldrd(Register rd, const Address& ad, Condition cond) {
ldrd(rd, Register(rd + 1), ad, cond);
}
void Thumb2Assembler::ldrd(Register rd, Register rd2, const Address& ad, Condition cond) {
CheckCondition(cond);
// Encoding T1.
// This is different from other loads. The encoding is like ARM.
int32_t encoding = B31 | B30 | B29 | B27 | B22 | B20 |
static_cast<int32_t>(rd) << 12 |
static_cast<int32_t>(rd2) << 8 |
ad.encodingThumbLdrdStrd();
Emit32(encoding);
}
void Thumb2Assembler::strd(Register rd, const Address& ad, Condition cond) {
strd(rd, Register(rd + 1), ad, cond);
}
void Thumb2Assembler::strd(Register rd, Register rd2, const Address& ad, Condition cond) {
CheckCondition(cond);
// Encoding T1.
// This is different from other loads. The encoding is like ARM.
int32_t encoding = B31 | B30 | B29 | B27 | B22 |
static_cast<int32_t>(rd) << 12 |
static_cast<int32_t>(rd2) << 8 |
ad.encodingThumbLdrdStrd();
Emit32(encoding);
}
void Thumb2Assembler::ldm(BlockAddressMode am,
Register base,
RegList regs,
Condition cond) {
CHECK_NE(regs, 0u); // Do not use ldm if there's nothing to load.
if (IsPowerOfTwo(regs)) {
// Thumb doesn't support one reg in the list.
// Find the register number.
int reg = CTZ(static_cast<uint32_t>(regs));
CHECK_LT(reg, 16);
CHECK(am == DB_W); // Only writeback is supported.
ldr(static_cast<Register>(reg), Address(base, kRegisterSize, Address::PostIndex), cond);
} else {
EmitMultiMemOp(cond, am, true, base, regs);
}
}
void Thumb2Assembler::stm(BlockAddressMode am,
Register base,
RegList regs,
Condition cond) {
CHECK_NE(regs, 0u); // Do not use stm if there's nothing to store.
if (IsPowerOfTwo(regs)) {
// Thumb doesn't support one reg in the list.
// Find the register number.
int reg = CTZ(static_cast<uint32_t>(regs));
CHECK_LT(reg, 16);
CHECK(am == IA || am == IA_W);
Address::Mode strmode = am == IA ? Address::PreIndex : Address::Offset;
str(static_cast<Register>(reg), Address(base, -kRegisterSize, strmode), cond);
} else {
EmitMultiMemOp(cond, am, false, base, regs);
}
}
bool Thumb2Assembler::vmovs(SRegister sd, float s_imm, Condition cond) {
uint32_t imm32 = bit_cast<uint32_t, float>(s_imm);
if (((imm32 & ((1 << 19) - 1)) == 0) &&
((((imm32 >> 25) & ((1 << 6) - 1)) == (1 << 5)) ||
(((imm32 >> 25) & ((1 << 6) - 1)) == ((1 << 5) -1)))) {
uint8_t imm8 = ((imm32 >> 31) << 7) | (((imm32 >> 29) & 1) << 6) |
((imm32 >> 19) & ((1 << 6) -1));
EmitVFPsss(cond, B23 | B21 | B20 | ((imm8 >> 4)*B16) | (imm8 & 0xf),
sd, S0, S0);
return true;
}
return false;
}
bool Thumb2Assembler::vmovd(DRegister dd, double d_imm, Condition cond) {
uint64_t imm64 = bit_cast<uint64_t, double>(d_imm);
if (((imm64 & ((1LL << 48) - 1)) == 0) &&
((((imm64 >> 54) & ((1 << 9) - 1)) == (1 << 8)) ||
(((imm64 >> 54) & ((1 << 9) - 1)) == ((1 << 8) -1)))) {
uint8_t imm8 = ((imm64 >> 63) << 7) | (((imm64 >> 61) & 1) << 6) |
((imm64 >> 48) & ((1 << 6) -1));
EmitVFPddd(cond, B23 | B21 | B20 | ((imm8 >> 4)*B16) | B8 | (imm8 & 0xf),
dd, D0, D0);
return true;
}
return false;
}
void Thumb2Assembler::vmovs(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B6, sd, S0, sm);
}
void Thumb2Assembler::vmovd(DRegister dd, DRegister dm, Condition cond) {
EmitVFPddd(cond, B23 | B21 | B20 | B6, dd, D0, dm);
}
void Thumb2Assembler::vadds(SRegister sd, SRegister sn, SRegister sm,
Condition cond) {
EmitVFPsss(cond, B21 | B20, sd, sn, sm);
}
void Thumb2Assembler::vaddd(DRegister dd, DRegister dn, DRegister dm,
Condition cond) {
EmitVFPddd(cond, B21 | B20, dd, dn, dm);
}
void Thumb2Assembler::vsubs(SRegister sd, SRegister sn, SRegister sm,
Condition cond) {
EmitVFPsss(cond, B21 | B20 | B6, sd, sn, sm);
}
void Thumb2Assembler::vsubd(DRegister dd, DRegister dn, DRegister dm,
Condition cond) {
EmitVFPddd(cond, B21 | B20 | B6, dd, dn, dm);
}
void Thumb2Assembler::vmuls(SRegister sd, SRegister sn, SRegister sm,
Condition cond) {
EmitVFPsss(cond, B21, sd, sn, sm);
}
void Thumb2Assembler::vmuld(DRegister dd, DRegister dn, DRegister dm,
Condition cond) {
EmitVFPddd(cond, B21, dd, dn, dm);
}
void Thumb2Assembler::vmlas(SRegister sd, SRegister sn, SRegister sm,
Condition cond) {
EmitVFPsss(cond, 0, sd, sn, sm);
}
void Thumb2Assembler::vmlad(DRegister dd, DRegister dn, DRegister dm,
Condition cond) {
EmitVFPddd(cond, 0, dd, dn, dm);
}
void Thumb2Assembler::vmlss(SRegister sd, SRegister sn, SRegister sm,
Condition cond) {
EmitVFPsss(cond, B6, sd, sn, sm);
}
void Thumb2Assembler::vmlsd(DRegister dd, DRegister dn, DRegister dm,
Condition cond) {
EmitVFPddd(cond, B6, dd, dn, dm);
}
void Thumb2Assembler::vdivs(SRegister sd, SRegister sn, SRegister sm,
Condition cond) {
EmitVFPsss(cond, B23, sd, sn, sm);
}
void Thumb2Assembler::vdivd(DRegister dd, DRegister dn, DRegister dm,
Condition cond) {
EmitVFPddd(cond, B23, dd, dn, dm);
}
void Thumb2Assembler::vabss(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B7 | B6, sd, S0, sm);
}
void Thumb2Assembler::vabsd(DRegister dd, DRegister dm, Condition cond) {
EmitVFPddd(cond, B23 | B21 | B20 | B7 | B6, dd, D0, dm);
}
void Thumb2Assembler::vnegs(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B16 | B6, sd, S0, sm);
}
void Thumb2Assembler::vnegd(DRegister dd, DRegister dm, Condition cond) {
EmitVFPddd(cond, B23 | B21 | B20 | B16 | B6, dd, D0, dm);
}
void Thumb2Assembler::vsqrts(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B16 | B7 | B6, sd, S0, sm);
}
void Thumb2Assembler::vsqrtd(DRegister dd, DRegister dm, Condition cond) {
EmitVFPddd(cond, B23 | B21 | B20 | B16 | B7 | B6, dd, D0, dm);
}
void Thumb2Assembler::vcvtsd(SRegister sd, DRegister dm, Condition cond) {
EmitVFPsd(cond, B23 | B21 | B20 | B18 | B17 | B16 | B8 | B7 | B6, sd, dm);
}
void Thumb2Assembler::vcvtds(DRegister dd, SRegister sm, Condition cond) {
EmitVFPds(cond, B23 | B21 | B20 | B18 | B17 | B16 | B7 | B6, dd, sm);
}
void Thumb2Assembler::vcvtis(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B19 | B18 | B16 | B7 | B6, sd, S0, sm);
}
void Thumb2Assembler::vcvtid(SRegister sd, DRegister dm, Condition cond) {
EmitVFPsd(cond, B23 | B21 | B20 | B19 | B18 | B16 | B8 | B7 | B6, sd, dm);
}
void Thumb2Assembler::vcvtsi(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B19 | B7 | B6, sd, S0, sm);
}
void Thumb2Assembler::vcvtdi(DRegister dd, SRegister sm, Condition cond) {
EmitVFPds(cond, B23 | B21 | B20 | B19 | B8 | B7 | B6, dd, sm);
}
void Thumb2Assembler::vcvtus(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B19 | B18 | B7 | B6, sd, S0, sm);
}
void Thumb2Assembler::vcvtud(SRegister sd, DRegister dm, Condition cond) {
EmitVFPsd(cond, B23 | B21 | B20 | B19 | B18 | B8 | B7 | B6, sd, dm);
}
void Thumb2Assembler::vcvtsu(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B19 | B6, sd, S0, sm);
}
void Thumb2Assembler::vcvtdu(DRegister dd, SRegister sm, Condition cond) {
EmitVFPds(cond, B23 | B21 | B20 | B19 | B8 | B6, dd, sm);
}
void Thumb2Assembler::vcmps(SRegister sd, SRegister sm, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B18 | B6, sd, S0, sm);
}
void Thumb2Assembler::vcmpd(DRegister dd, DRegister dm, Condition cond) {
EmitVFPddd(cond, B23 | B21 | B20 | B18 | B6, dd, D0, dm);
}
void Thumb2Assembler::vcmpsz(SRegister sd, Condition cond) {
EmitVFPsss(cond, B23 | B21 | B20 | B18 | B16 | B6, sd, S0, S0);
}
void Thumb2Assembler::vcmpdz(DRegister dd, Condition cond) {
EmitVFPddd(cond, B23 | B21 | B20 | B18 | B16 | B6, dd, D0, D0);
}
void Thumb2Assembler::b(Label* label, Condition cond) {
DCHECK_EQ(next_condition_, AL);
EmitBranch(cond, label, false, false);
}
void Thumb2Assembler::bl(Label* label, Condition cond) {
CheckCondition(cond);
EmitBranch(cond, label, true, false);
}
void Thumb2Assembler::blx(Label* label) {
EmitBranch(AL, label, true, true);
}
void Thumb2Assembler::MarkExceptionHandler(Label* label) {
EmitDataProcessing(AL, TST, kCcSet, PC, R0, ShifterOperand(0));
Label l;
b(&l);
EmitBranch(AL, label, false, false);
Bind(&l);
}
void Thumb2Assembler::Emit32(int32_t value) {
AssemblerBuffer::EnsureCapacity ensured(&buffer_);
buffer_.Emit<int16_t>(value >> 16);
buffer_.Emit<int16_t>(value & 0xffff);
}
void Thumb2Assembler::Emit16(int16_t value) {
AssemblerBuffer::EnsureCapacity ensured(&buffer_);
buffer_.Emit<int16_t>(value);
}
bool Thumb2Assembler::Is32BitDataProcessing(Condition cond,
Opcode opcode,
SetCc set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
if (force_32bit_) {
return true;
}
// Check special case for SP relative ADD and SUB immediate.
if ((opcode == ADD || opcode == SUB) && rn == SP && so.IsImmediate() && set_cc != kCcSet) {
// If the immediate is in range, use 16 bit.
if (rd == SP) {
if (so.GetImmediate() < (1 << 9)) { // 9 bit immediate.
return false;
}
} else if (!IsHighRegister(rd) && opcode == ADD) {
if (so.GetImmediate() < (1 << 10)) { // 10 bit immediate.
return false;
}
}
}
bool can_contain_high_register =
(opcode == CMP) ||
(opcode == MOV && set_cc != kCcSet) ||
((opcode == ADD) && (rn == rd) && set_cc != kCcSet);
if (IsHighRegister(rd) || IsHighRegister(rn)) {
if (!can_contain_high_register) {
return true;
}
// There are high register instructions available for this opcode.
// However, there is no actual shift available, neither for ADD nor for MOV (ASR/LSR/LSL/ROR).
if (so.IsShift() && (so.GetShift() == RRX || so.GetImmediate() != 0u)) {
return true;
}
// The ADD and MOV instructions that work with high registers don't have 16-bit
// immediate variants.
if (so.IsImmediate()) {
return true;
}
}
if (so.IsRegister() && IsHighRegister(so.GetRegister()) && !can_contain_high_register) {
return true;
}
bool rn_is_valid = true;
// Check for single operand instructions and ADD/SUB.
switch (opcode) {
case CMP:
case MOV:
case TST:
case MVN:
rn_is_valid = false; // There is no Rn for these instructions.
break;
case TEQ:
case ORN:
return true;
case ADD:
case SUB:
break;
default:
if (so.IsRegister() && rd != rn) {
return true;
}
}
if (so.IsImmediate()) {
if (opcode == RSB) {
DCHECK(rn_is_valid);
if (so.GetImmediate() != 0u) {
return true;
}
} else if (rn_is_valid && rn != rd) {
// The only thumb1 instructions with a register and an immediate are ADD and SUB
// with a 3-bit immediate, and RSB with zero immediate.
if (opcode == ADD || opcode == SUB) {
if ((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet) {
return true; // Cannot match "setflags".
}
if (!IsUint<3>(so.GetImmediate()) && !IsUint<3>(-so.GetImmediate())) {
return true;
}
} else {
return true;
}
} else {
// ADD, SUB, CMP and MOV may be thumb1 only if the immediate is 8 bits.
if (!(opcode == ADD || opcode == SUB || opcode == MOV || opcode == CMP)) {
return true;
} else if (opcode != CMP && ((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet)) {
return true; // Cannot match "setflags" for ADD, SUB or MOV.
} else {
// For ADD and SUB allow also negative 8-bit immediate as we will emit the oposite opcode.
if (!IsUint<8>(so.GetImmediate()) &&
(opcode == MOV || opcode == CMP || !IsUint<8>(-so.GetImmediate()))) {
return true;
}
}
}
} else {
DCHECK(so.IsRegister());
if (so.IsShift()) {
// Shift operand - check if it is a MOV convertible to a 16-bit shift instruction.
if (opcode != MOV) {
return true;
}
// Check for MOV with an ROR/RRX. There is no 16-bit ROR immediate and no 16-bit RRX.
if (so.GetShift() == ROR || so.GetShift() == RRX) {
return true;
}
// 16-bit shifts set condition codes if and only if outside IT block,
// i.e. if and only if cond == AL.
if ((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet) {
return true;
}
} else {
// Register operand without shift.
switch (opcode) {
case ADD:
// The 16-bit ADD that cannot contain high registers can set condition codes
// if and only if outside IT block, i.e. if and only if cond == AL.
if (!can_contain_high_register &&
((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet)) {
return true;
}
break;
case AND:
case BIC:
case EOR:
case ORR:
case MVN:
case ADC:
case SUB:
case SBC:
// These 16-bit opcodes set condition codes if and only if outside IT block,
// i.e. if and only if cond == AL.
if ((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet) {
return true;
}
break;
case RSB:
case RSC:
// No 16-bit RSB/RSC Rd, Rm, Rn. It would be equivalent to SUB/SBC Rd, Rn, Rm.
return true;
case CMP:
default:
break;
}
}
}
// The instruction can be encoded in 16 bits.
return false;
}
void Thumb2Assembler::Emit32BitDataProcessing(Condition cond ATTRIBUTE_UNUSED,
Opcode opcode,
SetCc set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
uint8_t thumb_opcode = 255U /* 0b11111111 */;
switch (opcode) {
case AND: thumb_opcode = 0U /* 0b0000 */; break;
case EOR: thumb_opcode = 4U /* 0b0100 */; break;
case SUB: thumb_opcode = 13U /* 0b1101 */; break;
case RSB: thumb_opcode = 14U /* 0b1110 */; break;
case ADD: thumb_opcode = 8U /* 0b1000 */; break;
case ADC: thumb_opcode = 10U /* 0b1010 */; break;
case SBC: thumb_opcode = 11U /* 0b1011 */; break;
case RSC: break;
case TST: thumb_opcode = 0U /* 0b0000 */; DCHECK(set_cc == kCcSet); rd = PC; break;
case TEQ: thumb_opcode = 4U /* 0b0100 */; DCHECK(set_cc == kCcSet); rd = PC; break;
case CMP: thumb_opcode = 13U /* 0b1101 */; DCHECK(set_cc == kCcSet); rd = PC; break;
case CMN: thumb_opcode = 8U /* 0b1000 */; DCHECK(set_cc == kCcSet); rd = PC; break;
case ORR: thumb_opcode = 2U /* 0b0010 */; break;
case MOV: thumb_opcode = 2U /* 0b0010 */; rn = PC; break;
case BIC: thumb_opcode = 1U /* 0b0001 */; break;
case MVN: thumb_opcode = 3U /* 0b0011 */; rn = PC; break;
case ORN: thumb_opcode = 3U /* 0b0011 */; break;
default:
break;
}
if (thumb_opcode == 255U /* 0b11111111 */) {
LOG(FATAL) << "Invalid thumb2 opcode " << opcode;
UNREACHABLE();
}
int32_t encoding = 0;
if (so.IsImmediate()) {
// Check special cases.
if ((opcode == SUB || opcode == ADD) && (so.GetImmediate() < (1u << 12)) &&
/* Prefer T3 encoding to T4. */ !ShifterOperandCanAlwaysHold(so.GetImmediate())) {
if (set_cc != kCcSet) {
if (opcode == SUB) {
thumb_opcode = 5U;
} else if (opcode == ADD) {
thumb_opcode = 0U;
}
}
uint32_t imm = so.GetImmediate();
uint32_t i = (imm >> 11) & 1;
uint32_t imm3 = (imm >> 8) & 7U /* 0b111 */;
uint32_t imm8 = imm & 0xff;
encoding = B31 | B30 | B29 | B28 |
(set_cc == kCcSet ? B20 : B25) |
thumb_opcode << 21 |
rn << 16 |
rd << 8 |
i << 26 |
imm3 << 12 |
imm8;
} else {
// Modified immediate.
uint32_t imm = ModifiedImmediate(so.encodingThumb());
if (imm == kInvalidModifiedImmediate) {
LOG(FATAL) << "Immediate value cannot fit in thumb2 modified immediate";
UNREACHABLE();
}
encoding = B31 | B30 | B29 | B28 |
thumb_opcode << 21 |
(set_cc == kCcSet ? B20 : 0) |
rn << 16 |
rd << 8 |
imm;
}
} else if (so.IsRegister()) {
// Register (possibly shifted)
encoding = B31 | B30 | B29 | B27 | B25 |
thumb_opcode << 21 |
(set_cc == kCcSet ? B20 : 0) |
rn << 16 |
rd << 8 |
so.encodingThumb();
}
Emit32(encoding);
}
void Thumb2Assembler::Emit16BitDataProcessing(Condition cond,
Opcode opcode,
SetCc set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
if (opcode == ADD || opcode == SUB) {
Emit16BitAddSub(cond, opcode, set_cc, rn, rd, so);
return;
}
uint8_t thumb_opcode = 255U /* 0b11111111 */;
// Thumb1.
uint8_t dp_opcode = 1U /* 0b01 */;
uint8_t opcode_shift = 6;
uint8_t rd_shift = 0;
uint8_t rn_shift = 3;
uint8_t immediate_shift = 0;
bool use_immediate = false;
uint8_t immediate = 0;
if (opcode == MOV && so.IsRegister() && so.IsShift()) {
// Convert shifted mov operand2 into 16 bit opcodes.
dp_opcode = 0;
opcode_shift = 11;
use_immediate = true;
immediate = so.GetImmediate();
immediate_shift = 6;
rn = so.GetRegister();
switch (so.GetShift()) {
case LSL:
DCHECK_LE(immediate, 31u);
thumb_opcode = 0U /* 0b00 */;
break;
case LSR:
DCHECK(1 <= immediate && immediate <= 32);
immediate &= 31; // 32 is encoded as 0.
thumb_opcode = 1U /* 0b01 */;
break;
case ASR:
DCHECK(1 <= immediate && immediate <= 32);
immediate &= 31; // 32 is encoded as 0.
thumb_opcode = 2U /* 0b10 */;
break;
case ROR: // No 16-bit ROR immediate.
case RRX: // No 16-bit RRX.
default:
LOG(FATAL) << "Unexpected shift: " << so.GetShift();
UNREACHABLE();
}
} else {
if (so.IsImmediate()) {
use_immediate = true;
immediate = so.GetImmediate();
} else {
CHECK(!(so.IsRegister() && so.IsShift() && so.GetSecondRegister() != kNoRegister))
<< "No register-shifted register instruction available in thumb";
// Adjust rn and rd: only two registers will be emitted.
switch (opcode) {
case AND:
case ORR:
case EOR:
case RSB:
case ADC:
case SBC:
case BIC: {
// Sets condition codes if and only if outside IT block,
// check that it complies with set_cc.
DCHECK((cond == AL) ? set_cc != kCcKeep : set_cc != kCcSet);
if (rn == rd) {
rn = so.GetRegister();
} else {
CHECK_EQ(rd, so.GetRegister());
}
break;
}
case CMP:
case CMN: {
CHECK_EQ(rd, 0);
rd = rn;
rn = so.GetRegister();
break;
}
case MVN: {
// Sets condition codes if and only if outside IT block,
// check that it complies with set_cc.
DCHECK((cond == AL) ? set_cc != kCcKeep : set_cc != kCcSet);
CHECK_EQ(rn, 0);
rn = so.GetRegister();
break;
}
case TST:
case TEQ: {
DCHECK(set_cc == kCcSet);
CHECK_EQ(rn, 0);
rn = so.GetRegister();
break;
}
default:
break;
}
}
switch (opcode) {
case AND: thumb_opcode = 0U /* 0b0000 */; break;
case ORR: thumb_opcode = 12U /* 0b1100 */; break;
case EOR: thumb_opcode = 1U /* 0b0001 */; break;
case RSB: thumb_opcode = 9U /* 0b1001 */; break;
case ADC: thumb_opcode = 5U /* 0b0101 */; break;
case SBC: thumb_opcode = 6U /* 0b0110 */; break;
case BIC: thumb_opcode = 14U /* 0b1110 */; break;
case TST: thumb_opcode = 8U /* 0b1000 */; CHECK(!use_immediate); break;
case MVN: thumb_opcode = 15U /* 0b1111 */; CHECK(!use_immediate); break;
case CMP: {
DCHECK(set_cc == kCcSet);
if (use_immediate) {
// T2 encoding.
dp_opcode = 0;
opcode_shift = 11;
thumb_opcode = 5U /* 0b101 */;
rd_shift = 8;
rn_shift = 8;
} else if (IsHighRegister(rd) || IsHighRegister(rn)) {
// Special cmp for high registers.
dp_opcode = 1U /* 0b01 */;
opcode_shift = 7;
// Put the top bit of rd into the bottom bit of the opcode.
thumb_opcode = 10U /* 0b0001010 */ | static_cast<uint32_t>(rd) >> 3;
rd = static_cast<Register>(static_cast<uint32_t>(rd) & 7U /* 0b111 */);
} else {
thumb_opcode = 10U /* 0b1010 */;
}
break;
}
case CMN: {
CHECK(!use_immediate);
thumb_opcode = 11U /* 0b1011 */;
break;
}
case MOV:
dp_opcode = 0;
if (use_immediate) {
// T2 encoding.
opcode_shift = 11;
thumb_opcode = 4U /* 0b100 */;
rd_shift = 8;
rn_shift = 8;
} else {
rn = so.GetRegister();
if (set_cc != kCcSet) {
// Special mov for high registers.
dp_opcode = 1U /* 0b01 */;
opcode_shift = 7;
// Put the top bit of rd into the bottom bit of the opcode.
thumb_opcode = 12U /* 0b0001100 */ | static_cast<uint32_t>(rd) >> 3;
rd = static_cast<Register>(static_cast<uint32_t>(rd) & 7U /* 0b111 */);
} else {
DCHECK(!IsHighRegister(rn));
DCHECK(!IsHighRegister(rd));
thumb_opcode = 0;
}
}
break;
case TEQ:
case RSC:
default:
LOG(FATAL) << "Invalid thumb1 opcode " << opcode;
break;
}
}
if (thumb_opcode == 255U /* 0b11111111 */) {
LOG(FATAL) << "Invalid thumb1 opcode " << opcode;
UNREACHABLE();
}
int16_t encoding = dp_opcode << 14 |
(thumb_opcode << opcode_shift) |
rd << rd_shift |
rn << rn_shift |
(use_immediate ? (immediate << immediate_shift) : 0);
Emit16(encoding);
}
// ADD and SUB are complex enough to warrant their own emitter.
void Thumb2Assembler::Emit16BitAddSub(Condition cond,
Opcode opcode,
SetCc set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
uint8_t dp_opcode = 0;
uint8_t opcode_shift = 6;
uint8_t rd_shift = 0;
uint8_t rn_shift = 3;
uint8_t immediate_shift = 0;
bool use_immediate = false;
uint32_t immediate = 0; // Should be at most 10 bits but keep the full immediate for CHECKs.
uint8_t thumb_opcode;
if (so.IsImmediate()) {
use_immediate = true;
immediate = so.GetImmediate();
if (!IsUint<10>(immediate)) {
// Flip ADD/SUB.
opcode = (opcode == ADD) ? SUB : ADD;
immediate = -immediate;
DCHECK(IsUint<10>(immediate)); // More stringent checks below.
}
}
switch (opcode) {
case ADD:
if (so.IsRegister()) {
Register rm = so.GetRegister();
if (rn == rd && set_cc != kCcSet) {
// Can use T2 encoding (allows 4 bit registers)
dp_opcode = 1U /* 0b01 */;
opcode_shift = 10;
thumb_opcode = 1U /* 0b0001 */;
// Make Rn also contain the top bit of rd.
rn = static_cast<Register>(static_cast<uint32_t>(rm) |
(static_cast<uint32_t>(rd) & 8U /* 0b1000 */) << 1);
rd = static_cast<Register>(static_cast<uint32_t>(rd) & 7U /* 0b111 */);
} else {
// T1.
DCHECK(!IsHighRegister(rd));
DCHECK(!IsHighRegister(rn));
DCHECK(!IsHighRegister(rm));
// Sets condition codes if and only if outside IT block,
// check that it complies with set_cc.
DCHECK((cond == AL) ? set_cc != kCcKeep : set_cc != kCcSet);
opcode_shift = 9;
thumb_opcode = 12U /* 0b01100 */;
immediate = static_cast<uint32_t>(so.GetRegister());
use_immediate = true;
immediate_shift = 6;
}
} else {
// Immediate.
if (rd == SP && rn == SP) {
// ADD sp, sp, #imm
dp_opcode = 2U /* 0b10 */;
thumb_opcode = 3U /* 0b11 */;
opcode_shift = 12;
CHECK(IsUint<9>(immediate));
CHECK_ALIGNED(immediate, 4);
// Remove rd and rn from instruction by orring it with immed and clearing bits.
rn = R0;
rd = R0;
rd_shift = 0;
rn_shift = 0;
immediate >>= 2;
} else if (rd != SP && rn == SP) {
// ADD rd, SP, #imm
dp_opcode = 2U /* 0b10 */;
thumb_opcode = 5U /* 0b101 */;
opcode_shift = 11;
CHECK(IsUint<10>(immediate));
CHECK_ALIGNED(immediate, 4);
// Remove rn from instruction.
rn = R0;
rn_shift = 0;
rd_shift = 8;
immediate >>= 2;
} else if (rn != rd) {
// Must use T1.
CHECK(IsUint<3>(immediate));
opcode_shift = 9;
thumb_opcode = 14U /* 0b01110 */;
immediate_shift = 6;
} else {
// T2 encoding.
CHECK(IsUint<8>(immediate));
opcode_shift = 11;
thumb_opcode = 6U /* 0b110 */;
rd_shift = 8;
rn_shift = 8;
}
}
break;
case SUB:
if (so.IsRegister()) {
// T1.
Register rm = so.GetRegister();
DCHECK(!IsHighRegister(rd));
DCHECK(!IsHighRegister(rn));
DCHECK(!IsHighRegister(rm));
// Sets condition codes if and only if outside IT block,
// check that it complies with set_cc.
DCHECK((cond == AL) ? set_cc != kCcKeep : set_cc != kCcSet);
opcode_shift = 9;
thumb_opcode = 13U /* 0b01101 */;
immediate = static_cast<uint32_t>(rm);
use_immediate = true;
immediate_shift = 6;
} else {
if (rd == SP && rn == SP) {
// SUB sp, sp, #imm
dp_opcode = 2U /* 0b10 */;
thumb_opcode = 0x61 /* 0b1100001 */;
opcode_shift = 7;
CHECK(IsUint<9>(immediate));
CHECK_ALIGNED(immediate, 4);
// Remove rd and rn from instruction by orring it with immed and clearing bits.
rn = R0;
rd = R0;
rd_shift = 0;
rn_shift = 0;
immediate >>= 2;
} else if (rn != rd) {
// Must use T1.
CHECK(IsUint<3>(immediate));
opcode_shift = 9;
thumb_opcode = 15U /* 0b01111 */;
immediate_shift = 6;
} else {
// T2 encoding.
CHECK(IsUint<8>(immediate));
opcode_shift = 11;
thumb_opcode = 7U /* 0b111 */;
rd_shift = 8;
rn_shift = 8;
}
}
break;
default:
LOG(FATAL) << "This opcode is not an ADD or SUB: " << opcode;
UNREACHABLE();
}
int16_t encoding = dp_opcode << 14 |
(thumb_opcode << opcode_shift) |
rd << rd_shift |
rn << rn_shift |
(use_immediate ? (immediate << immediate_shift) : 0);
Emit16(encoding);
}
void Thumb2Assembler::EmitDataProcessing(Condition cond,
Opcode opcode,
SetCc set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
CHECK_NE(rd, kNoRegister);
CheckCondition(cond);
if (Is32BitDataProcessing(cond, opcode, set_cc, rn, rd, so)) {
Emit32BitDataProcessing(cond, opcode, set_cc, rn, rd, so);
} else {
Emit16BitDataProcessing(cond, opcode, set_cc, rn, rd, so);
}
}
void Thumb2Assembler::EmitShift(Register rd,
Register rm,
Shift shift,
uint8_t amount,
Condition cond,
SetCc set_cc) {
CHECK_LT(amount, (1 << 5));
if ((IsHighRegister(rd) || IsHighRegister(rm) || shift == ROR || shift == RRX) ||
((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet)) {
uint16_t opcode = 0;
switch (shift) {
case LSL: opcode = 0U /* 0b00 */; break;
case LSR: opcode = 1U /* 0b01 */; break;
case ASR: opcode = 2U /* 0b10 */; break;
case ROR: opcode = 3U /* 0b11 */; break;
case RRX: opcode = 3U /* 0b11 */; amount = 0; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
UNREACHABLE();
}
// 32 bit.
int32_t encoding = B31 | B30 | B29 | B27 | B25 | B22 |
0xf << 16 | (set_cc == kCcSet ? B20 : 0);
uint32_t imm3 = amount >> 2;
uint32_t imm2 = amount & 3U /* 0b11 */;
encoding |= imm3 << 12 | imm2 << 6 | static_cast<int16_t>(rm) |
static_cast<int16_t>(rd) << 8 | opcode << 4;
Emit32(encoding);
} else {
// 16 bit shift
uint16_t opcode = 0;
switch (shift) {
case LSL: opcode = 0U /* 0b00 */; break;
case LSR: opcode = 1U /* 0b01 */; break;
case ASR: opcode = 2U /* 0b10 */; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
UNREACHABLE();
}
int16_t encoding = opcode << 11 | amount << 6 | static_cast<int16_t>(rm) << 3 |
static_cast<int16_t>(rd);
Emit16(encoding);
}
}
void Thumb2Assembler::EmitShift(Register rd,
Register rn,
Shift shift,
Register rm,
Condition cond,
SetCc set_cc) {
CHECK_NE(shift, RRX);
bool must_be_32bit = false;
if (IsHighRegister(rd) || IsHighRegister(rm) || IsHighRegister(rn) || rd != rn ||
((cond == AL) ? set_cc == kCcKeep : set_cc == kCcSet)) {
must_be_32bit = true;
}
if (must_be_32bit) {
uint16_t opcode = 0;
switch (shift) {
case LSL: opcode = 0U /* 0b00 */; break;
case LSR: opcode = 1U /* 0b01 */; break;
case ASR: opcode = 2U /* 0b10 */; break;
case ROR: opcode = 3U /* 0b11 */; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
UNREACHABLE();
}
// 32 bit.
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 |
0xf << 12 | (set_cc == kCcSet ? B20 : 0);
encoding |= static_cast<int16_t>(rn) << 16 | static_cast<int16_t>(rm) |
static_cast<int16_t>(rd) << 8 | opcode << 21;
Emit32(encoding);
} else {
uint16_t opcode = 0;
switch (shift) {
case LSL: opcode = 2U /* 0b0010 */; break;
case LSR: opcode = 3U /* 0b0011 */; break;
case ASR: opcode = 4U /* 0b0100 */; break;
case ROR: opcode = 7U /* 0b0111 */; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
UNREACHABLE();
}
int16_t encoding = B14 | opcode << 6 | static_cast<int16_t>(rm) << 3 |
static_cast<int16_t>(rd);
Emit16(encoding);
}
}
inline size_t Thumb2Assembler::Fixup::SizeInBytes(Size size) {
switch (size) {
case kBranch16Bit:
return 2u;
case kBranch32Bit:
return 4u;
case kCbxz16Bit:
return 2u;
case kCbxz32Bit:
return 4u;
case kCbxz48Bit:
return 6u;
case kLiteral1KiB:
return 2u;
case kLiteral4KiB:
return 4u;
case kLiteral64KiB:
return 8u;
case kLiteral1MiB:
return 10u;
case kLiteralFar:
return 14u;
case kLiteralAddr1KiB:
return 2u;
case kLiteralAddr4KiB:
return 4u;
case kLiteralAddr64KiB:
return 6u;
case kLiteralAddrFar:
return 10u;
case kLongOrFPLiteral1KiB:
return 4u;
case kLongOrFPLiteral256KiB:
return 10u;
case kLongOrFPLiteralFar:
return 14u;
}
LOG(FATAL) << "Unexpected size: " << static_cast<int>(size);
UNREACHABLE();
}
inline uint32_t Thumb2Assembler::Fixup::GetOriginalSizeInBytes() const {
return SizeInBytes(original_size_);
}
inline uint32_t Thumb2Assembler::Fixup::GetSizeInBytes() const {
return SizeInBytes(size_);
}
inline size_t Thumb2Assembler::Fixup::LiteralPoolPaddingSize(uint32_t current_code_size) {
// The code size must be a multiple of 2.
DCHECK_ALIGNED(current_code_size, 2);
// If it isn't a multiple of 4, we need to add a 2-byte padding before the literal pool.
return current_code_size & 2;
}
inline int32_t Thumb2Assembler::Fixup::GetOffset(uint32_t current_code_size) const {
static constexpr int32_t int32_min = std::numeric_limits<int32_t>::min();
static constexpr int32_t int32_max = std::numeric_limits<int32_t>::max();
DCHECK_LE(target_, static_cast<uint32_t>(int32_max));
DCHECK_LE(location_, static_cast<uint32_t>(int32_max));
DCHECK_LE(adjustment_, static_cast<uint32_t>(int32_max));
int32_t diff = static_cast<int32_t>(target_) - static_cast<int32_t>(location_);
if (target_ > location_) {
DCHECK_LE(adjustment_, static_cast<uint32_t>(int32_max - diff));
diff += static_cast<int32_t>(adjustment_);
} else {
DCHECK_LE(int32_min + static_cast<int32_t>(adjustment_), diff);
diff -= static_cast<int32_t>(adjustment_);
}
// The default PC adjustment for Thumb2 is 4 bytes.
DCHECK_GE(diff, int32_min + 4);
diff -= 4;
// Add additional adjustment for instructions preceding the PC usage, padding
// before the literal pool and rounding down the PC for literal loads.
switch (GetSize()) {
case kBranch16Bit:
case kBranch32Bit:
break;
case kCbxz16Bit:
break;
case kCbxz32Bit:
case kCbxz48Bit:
DCHECK_GE(diff, int32_min + 2);
diff -= 2; // Extra CMP Rn, #0, 16-bit.
break;
case kLiteral1KiB:
case kLiteral4KiB:
case kLongOrFPLiteral1KiB:
case kLiteralAddr1KiB:
case kLiteralAddr4KiB:
DCHECK(diff >= 0 || (GetSize() == kLiteral1KiB && diff == -2));
diff += LiteralPoolPaddingSize(current_code_size);
// Load literal instructions round down the PC+4 to a multiple of 4, so if the PC
// isn't a multiple of 2, we need to adjust. Since we already adjusted for the target
// being aligned, current PC alignment can be inferred from diff.
DCHECK_ALIGNED(diff, 2);
diff = diff + (diff & 2);
DCHECK_GE(diff, 0);
break;
case kLiteral1MiB:
case kLiteral64KiB:
case kLongOrFPLiteral256KiB:
case kLiteralAddr64KiB:
DCHECK_GE(diff, 4); // The target must be at least 4 bytes after the ADD rX, PC.
diff -= 4; // One extra 32-bit MOV.
diff += LiteralPoolPaddingSize(current_code_size);
break;
case kLiteralFar:
case kLongOrFPLiteralFar:
case kLiteralAddrFar:
DCHECK_GE(diff, 8); // The target must be at least 4 bytes after the ADD rX, PC.
diff -= 8; // Extra MOVW+MOVT; both 32-bit.
diff += LiteralPoolPaddingSize(current_code_size);
break;
}
return diff;
}
inline size_t Thumb2Assembler::Fixup::IncreaseSize(Size new_size) {
DCHECK_NE(target_, kUnresolved);
Size old_size = size_;
size_ = new_size;
DCHECK_GT(SizeInBytes(new_size), SizeInBytes(old_size));
size_t adjustment = SizeInBytes(new_size) - SizeInBytes(old_size);
if (target_ > location_) {
adjustment_ += adjustment;
}
return adjustment;
}
uint32_t Thumb2Assembler::Fixup::AdjustSizeIfNeeded(uint32_t current_code_size) {
uint32_t old_code_size = current_code_size;
switch (GetSize()) {
case kBranch16Bit:
if (IsInt(cond_ != AL ? 9 : 12, GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kBranch32Bit);
FALLTHROUGH_INTENDED;
case kBranch32Bit:
// We don't support conditional branches beyond +-1MiB
// or unconditional branches beyond +-16MiB.
break;
case kCbxz16Bit:
if (IsUint<7>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kCbxz32Bit);
FALLTHROUGH_INTENDED;
case kCbxz32Bit:
if (IsInt<9>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kCbxz48Bit);
FALLTHROUGH_INTENDED;
case kCbxz48Bit:
// We don't support conditional branches beyond +-1MiB.
break;
case kLiteral1KiB:
DCHECK(!IsHighRegister(rn_));
if (IsUint<10>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteral4KiB);
FALLTHROUGH_INTENDED;
case kLiteral4KiB:
if (IsUint<12>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteral64KiB);
FALLTHROUGH_INTENDED;
case kLiteral64KiB:
// Can't handle high register which we can encounter by fall-through from kLiteral4KiB.
if (!IsHighRegister(rn_) && IsUint<16>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteral1MiB);
FALLTHROUGH_INTENDED;
case kLiteral1MiB:
if (IsUint<20>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteralFar);
FALLTHROUGH_INTENDED;
case kLiteralFar:
// This encoding can reach any target.
break;
case kLiteralAddr1KiB:
DCHECK(!IsHighRegister(rn_));
if (IsUint<10>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteralAddr4KiB);
FALLTHROUGH_INTENDED;
case kLiteralAddr4KiB:
if (IsUint<12>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteralAddr64KiB);
FALLTHROUGH_INTENDED;
case kLiteralAddr64KiB:
if (IsUint<16>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLiteralAddrFar);
FALLTHROUGH_INTENDED;
case kLiteralAddrFar:
// This encoding can reach any target.
break;
case kLongOrFPLiteral1KiB:
if (IsUint<10>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLongOrFPLiteral256KiB);
FALLTHROUGH_INTENDED;
case kLongOrFPLiteral256KiB:
if (IsUint<18>(GetOffset(current_code_size))) {
break;
}
current_code_size += IncreaseSize(kLongOrFPLiteralFar);
FALLTHROUGH_INTENDED;
case kLongOrFPLiteralFar:
// This encoding can reach any target.
break;
}
return current_code_size - old_code_size;
}
void Thumb2Assembler::Fixup::Emit(AssemblerBuffer* buffer, uint32_t code_size) const {
switch (GetSize()) {
case kBranch16Bit: {
DCHECK(type_ == kUnconditional || type_ == kConditional);
DCHECK_EQ(type_ == kConditional, cond_ != AL);
int16_t encoding = BEncoding16(GetOffset(code_size), cond_);
buffer->Store<int16_t>(location_, encoding);
break;
}
case kBranch32Bit: {
DCHECK(type_ == kConditional || type_ == kUnconditional ||
type_ == kUnconditionalLink || type_ == kUnconditionalLinkX);
DCHECK_EQ(type_ == kConditional, cond_ != AL);
int32_t encoding = BEncoding32(GetOffset(code_size), cond_);
if (type_ == kUnconditionalLink) {
DCHECK_NE(encoding & B12, 0);
encoding |= B14;
} else if (type_ == kUnconditionalLinkX) {
DCHECK_NE(encoding & B12, 0);
encoding ^= B14 | B12;
}
buffer->Store<int16_t>(location_, encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(encoding & 0xffff));
break;
}
case kCbxz16Bit: {
DCHECK(type_ == kCompareAndBranchXZero);
int16_t encoding = CbxzEncoding16(rn_, GetOffset(code_size), cond_);
buffer->Store<int16_t>(location_, encoding);
break;
}
case kCbxz32Bit: {
DCHECK(type_ == kCompareAndBranchXZero);
DCHECK(cond_ == EQ || cond_ == NE);
int16_t cmp_encoding = CmpRnImm8Encoding16(rn_, 0);
int16_t b_encoding = BEncoding16(GetOffset(code_size), cond_);
buffer->Store<int16_t>(location_, cmp_encoding);
buffer->Store<int16_t>(location_ + 2, b_encoding);
break;
}
case kCbxz48Bit: {
DCHECK(type_ == kCompareAndBranchXZero);
DCHECK(cond_ == EQ || cond_ == NE);
int16_t cmp_encoding = CmpRnImm8Encoding16(rn_, 0);
int32_t b_encoding = BEncoding32(GetOffset(code_size), cond_);
buffer->Store<int16_t>(location_, cmp_encoding);
buffer->Store<int16_t>(location_ + 2u, b_encoding >> 16);
buffer->Store<int16_t>(location_ + 4u, static_cast<int16_t>(b_encoding & 0xffff));
break;
}
case kLiteral1KiB: {
DCHECK(type_ == kLoadLiteralNarrow);
int16_t encoding = LdrLitEncoding16(rn_, GetOffset(code_size));
buffer->Store<int16_t>(location_, encoding);
break;
}
case kLiteral4KiB: {
DCHECK(type_ == kLoadLiteralNarrow);
// GetOffset() uses PC+4 but load literal uses AlignDown(PC+4, 4). Adjust offset accordingly.
int32_t encoding = LdrLitEncoding32(rn_, GetOffset(code_size));
buffer->Store<int16_t>(location_, encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(encoding & 0xffff));
break;
}
case kLiteral64KiB: {
DCHECK(type_ == kLoadLiteralNarrow);
int32_t mov_encoding = MovwEncoding32(rn_, GetOffset(code_size));
int16_t add_pc_encoding = AddRdnRmEncoding16(rn_, PC);
int16_t ldr_encoding = LdrRtRnImm5Encoding16(rn_, rn_, 0);
buffer->Store<int16_t>(location_, mov_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(mov_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, add_pc_encoding);
buffer->Store<int16_t>(location_ + 6u, ldr_encoding);
break;
}
case kLiteral1MiB: {
DCHECK(type_ == kLoadLiteralNarrow);
int32_t offset = GetOffset(code_size);
int32_t mov_encoding = MovModImmEncoding32(rn_, offset & ~0xfff);
int16_t add_pc_encoding = AddRdnRmEncoding16(rn_, PC);
int32_t ldr_encoding = LdrRtRnImm12Encoding(rn_, rn_, offset & 0xfff);
buffer->Store<int16_t>(location_, mov_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(mov_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, add_pc_encoding);
buffer->Store<int16_t>(location_ + 6u, ldr_encoding >> 16);
buffer->Store<int16_t>(location_ + 8u, static_cast<int16_t>(ldr_encoding & 0xffff));
break;
}
case kLiteralFar: {
DCHECK(type_ == kLoadLiteralNarrow);
int32_t offset = GetOffset(code_size);
int32_t movw_encoding = MovwEncoding32(rn_, offset & 0xffff);
int32_t movt_encoding = MovtEncoding32(rn_, offset & ~0xffff);
int16_t add_pc_encoding = AddRdnRmEncoding16(rn_, PC);
int32_t ldr_encoding = LdrRtRnImm12Encoding(rn_, rn_, 0);
buffer->Store<int16_t>(location_, movw_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(movw_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, movt_encoding >> 16);
buffer->Store<int16_t>(location_ + 6u, static_cast<int16_t>(movt_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 8u, add_pc_encoding);
buffer->Store<int16_t>(location_ + 10u, ldr_encoding >> 16);
buffer->Store<int16_t>(location_ + 12u, static_cast<int16_t>(ldr_encoding & 0xffff));
break;
}
case kLiteralAddr1KiB: {
DCHECK(type_ == kLoadLiteralAddr);
int16_t encoding = AdrEncoding16(rn_, GetOffset(code_size));
buffer->Store<int16_t>(location_, encoding);
break;
}
case kLiteralAddr4KiB: {
DCHECK(type_ == kLoadLiteralAddr);
int32_t encoding = AdrEncoding32(rn_, GetOffset(code_size));
buffer->Store<int16_t>(location_, encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(encoding & 0xffff));
break;
}
case kLiteralAddr64KiB: {
DCHECK(type_ == kLoadLiteralAddr);
int32_t mov_encoding = MovwEncoding32(rn_, GetOffset(code_size));
int16_t add_pc_encoding = AddRdnRmEncoding16(rn_, PC);
buffer->Store<int16_t>(location_, mov_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(mov_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, add_pc_encoding);
break;
}
case kLiteralAddrFar: {
DCHECK(type_ == kLoadLiteralAddr);
int32_t offset = GetOffset(code_size);
int32_t movw_encoding = MovwEncoding32(rn_, offset & 0xffff);
int32_t movt_encoding = MovtEncoding32(rn_, offset & ~0xffff);
int16_t add_pc_encoding = AddRdnRmEncoding16(rn_, PC);
buffer->Store<int16_t>(location_, movw_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(movw_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, movt_encoding >> 16);
buffer->Store<int16_t>(location_ + 6u, static_cast<int16_t>(movt_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 8u, add_pc_encoding);
break;
}
case kLongOrFPLiteral1KiB: {
int32_t encoding = LoadWideOrFpEncoding(PC, GetOffset(code_size)); // DCHECKs type_.
buffer->Store<int16_t>(location_, encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(encoding & 0xffff));
break;
}
case kLongOrFPLiteral256KiB: {
int32_t offset = GetOffset(code_size);
int32_t mov_encoding = MovModImmEncoding32(IP, offset & ~0x3ff);
int16_t add_pc_encoding = AddRdnRmEncoding16(IP, PC);
int32_t ldr_encoding = LoadWideOrFpEncoding(IP, offset & 0x3ff); // DCHECKs type_.
buffer->Store<int16_t>(location_, mov_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(mov_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, add_pc_encoding);
buffer->Store<int16_t>(location_ + 6u, ldr_encoding >> 16);
buffer->Store<int16_t>(location_ + 8u, static_cast<int16_t>(ldr_encoding & 0xffff));
break;
}
case kLongOrFPLiteralFar: {
int32_t offset = GetOffset(code_size);
int32_t movw_encoding = MovwEncoding32(IP, offset & 0xffff);
int32_t movt_encoding = MovtEncoding32(IP, offset & ~0xffff);
int16_t add_pc_encoding = AddRdnRmEncoding16(IP, PC);
int32_t ldr_encoding = LoadWideOrFpEncoding(IP, 0); // DCHECKs type_.
buffer->Store<int16_t>(location_, movw_encoding >> 16);
buffer->Store<int16_t>(location_ + 2u, static_cast<int16_t>(movw_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 4u, movt_encoding >> 16);
buffer->Store<int16_t>(location_ + 6u, static_cast<int16_t>(movt_encoding & 0xffff));
buffer->Store<int16_t>(location_ + 8u, add_pc_encoding);
buffer->Store<int16_t>(location_ + 10u, ldr_encoding >> 16);
buffer->Store<int16_t>(location_ + 12u, static_cast<int16_t>(ldr_encoding & 0xffff));
break;
}
}
}
uint16_t Thumb2Assembler::EmitCompareAndBranch(Register rn, uint16_t prev, bool n) {
CHECK(IsLowRegister(rn));
uint32_t location = buffer_.Size();
// This is always unresolved as it must be a forward branch.
Emit16(prev); // Previous link.
return AddFixup(Fixup::CompareAndBranch(location, rn, n ? NE : EQ));
}
// NOTE: this only support immediate offsets, not [rx,ry].
// TODO: support [rx,ry] instructions.
void Thumb2Assembler::EmitLoadStore(Condition cond,
bool load,
bool byte,
bool half,
bool is_signed,
Register rd,
const Address& ad) {
CHECK_NE(rd, kNoRegister);
CheckCondition(cond);
bool must_be_32bit = force_32bit_;
if (IsHighRegister(rd)) {
must_be_32bit = true;
}
Register rn = ad.GetRegister();
if (IsHighRegister(rn) && rn != SP && rn != PC) {
must_be_32bit = true;
}
if (is_signed || ad.GetOffset() < 0 || ad.GetMode() != Address::Offset) {
must_be_32bit = true;
}
if (ad.IsImmediate()) {
// Immediate offset
int32_t offset = ad.GetOffset();
// The 16 bit SP relative instruction can only have a 10 bit offset.
if (rn == SP && offset >= (1 << 10)) {
must_be_32bit = true;
}
if (byte) {
// 5 bit offset, no shift.
if (offset >= (1 << 5)) {
must_be_32bit = true;
}
} else if (half) {
// 6 bit offset, shifted by 1.
if (offset >= (1 << 6)) {
must_be_32bit = true;
}
} else {
// 7 bit offset, shifted by 2.
if (offset >= (1 << 7)) {
must_be_32bit = true;
}
}
if (must_be_32bit) {
int32_t encoding = B31 | B30 | B29 | B28 | B27 |
(load ? B20 : 0) |
(is_signed ? B24 : 0) |
static_cast<uint32_t>(rd) << 12 |
ad.encodingThumb(true) |
(byte ? 0 : half ? B21 : B22);
Emit32(encoding);
} else {
// 16 bit thumb1.
uint8_t opA = 0;
bool sp_relative = false;
if (byte) {
opA = 7U /* 0b0111 */;
} else if (half) {
opA = 8U /* 0b1000 */;
} else {
if (rn == SP) {
opA = 9U /* 0b1001 */;
sp_relative = true;
} else {
opA = 6U /* 0b0110 */;
}
}
int16_t encoding = opA << 12 |
(load ? B11 : 0);
CHECK_GE(offset, 0);
if (sp_relative) {
// SP relative, 10 bit offset.
CHECK_LT(offset, (1 << 10));
CHECK_ALIGNED(offset, 4);
encoding |= rd << 8 | offset >> 2;
} else {
// No SP relative. The offset is shifted right depending on
// the size of the load/store.
encoding |= static_cast<uint32_t>(rd);
if (byte) {
// 5 bit offset, no shift.
CHECK_LT(offset, (1 << 5));
} else if (half) {
// 6 bit offset, shifted by 1.
CHECK_LT(offset, (1 << 6));
CHECK_ALIGNED(offset, 2);
offset >>= 1;
} else {
// 7 bit offset, shifted by 2.
CHECK_LT(offset, (1 << 7));
CHECK_ALIGNED(offset, 4);
offset >>= 2;
}
encoding |= rn << 3 | offset << 6;
}
Emit16(encoding);
}
} else {
// Register shift.
if (ad.GetRegister() == PC) {
// PC relative literal encoding.
int32_t offset = ad.GetOffset();
if (must_be_32bit || offset < 0 || offset >= (1 << 10) || !load) {
int32_t up = B23;
if (offset < 0) {
offset = -offset;
up = 0;
}
CHECK_LT(offset, (1 << 12));
int32_t encoding = 0x1f << 27 | 0xf << 16 | B22 | (load ? B20 : 0) |
offset | up |
static_cast<uint32_t>(rd) << 12;
Emit32(encoding);
} else {
// 16 bit literal load.
CHECK_GE(offset, 0);
CHECK_LT(offset, (1 << 10));
int32_t encoding = B14 | (load ? B11 : 0) | static_cast<uint32_t>(rd) << 8 | offset >> 2;
Emit16(encoding);
}
} else {
if (ad.GetShiftCount() != 0) {
// If there is a shift count this must be 32 bit.
must_be_32bit = true;
} else if (IsHighRegister(ad.GetRegisterOffset())) {
must_be_32bit = true;
}
if (must_be_32bit) {
int32_t encoding = 0x1f << 27 | (load ? B20 : 0) | static_cast<uint32_t>(rd) << 12 |
ad.encodingThumb(true);
if (half) {
encoding |= B21;
} else if (!byte) {
encoding |= B22;
}
Emit32(encoding);
} else {
// 16 bit register offset.
int32_t encoding = B14 | B12 | (load ? B11 : 0) | static_cast<uint32_t>(rd) |
ad.encodingThumb(false);
if (byte) {
encoding |= B10;
} else if (half) {
encoding |= B9;
}
Emit16(encoding);
}
}
}
}
void Thumb2Assembler::EmitMultiMemOp(Condition cond,
BlockAddressMode bam,
bool load,
Register base,
RegList regs) {
CHECK_NE(base, kNoRegister);
CheckCondition(cond);
bool must_be_32bit = force_32bit_;
if (!must_be_32bit && base == SP && bam == (load ? IA_W : DB_W) &&
(regs & 0xff00 & ~(1 << (load ? PC : LR))) == 0) {
// Use 16-bit PUSH/POP.
int16_t encoding = B15 | B13 | B12 | (load ? B11 : 0) | B10 |
((regs & (1 << (load ? PC : LR))) != 0 ? B8 : 0) | (regs & 0x00ff);
Emit16(encoding);
return;
}
if ((regs & 0xff00) != 0) {
must_be_32bit = true;
}
bool w_bit = bam == IA_W || bam == DB_W || bam == DA_W || bam == IB_W;
// 16 bit always uses writeback.
if (!w_bit) {
must_be_32bit = true;
}
if (must_be_32bit) {
uint32_t op = 0;
switch (bam) {
case IA:
case IA_W:
op = 1U /* 0b01 */;
break;
case DB:
case DB_W:
op = 2U /* 0b10 */;
break;
case DA:
case IB:
case DA_W:
case IB_W:
LOG(FATAL) << "LDM/STM mode not supported on thumb: " << bam;
UNREACHABLE();
}
if (load) {
// Cannot have SP in the list.
CHECK_EQ((regs & (1 << SP)), 0);
} else {
// Cannot have PC or SP in the list.
CHECK_EQ((regs & (1 << PC | 1 << SP)), 0);
}
int32_t encoding = B31 | B30 | B29 | B27 |
(op << 23) |
(load ? B20 : 0) |
base << 16 |
regs |
(w_bit << 21);
Emit32(encoding);
} else {
int16_t encoding = B15 | B14 |
(load ? B11 : 0) |
base << 8 |
regs;
Emit16(encoding);
}
}
void Thumb2Assembler::EmitBranch(Condition cond, Label* label, bool link, bool x) {
bool use32bit = IsForced32Bit() || !CanRelocateBranches();
uint32_t pc = buffer_.Size();
Fixup::Type branch_type;
if (cond == AL) {
if (link) {
use32bit = true;
if (x) {
branch_type = Fixup::kUnconditionalLinkX; // BLX.
} else {
branch_type = Fixup::kUnconditionalLink; // BX.
}
} else {
branch_type = Fixup::kUnconditional; // B.
// The T2 encoding offset is `SignExtend(imm11:'0', 32)` and there is a PC adjustment of 4.
static constexpr size_t kMaxT2BackwardDistance = (1u << 11) - 4u;
if (!use32bit && label->IsBound() && pc - label->Position() > kMaxT2BackwardDistance) {
use32bit = true;
}
}
} else {
branch_type = Fixup::kConditional; // B<cond>.
// The T1 encoding offset is `SignExtend(imm8:'0', 32)` and there is a PC adjustment of 4.
static constexpr size_t kMaxT1BackwardDistance = (1u << 8) - 4u;
if (!use32bit && label->IsBound() && pc - label->Position() > kMaxT1BackwardDistance) {
use32bit = true;
}
}
Fixup::Size size = use32bit ? Fixup::kBranch32Bit : Fixup::kBranch16Bit;
FixupId branch_id = AddFixup(Fixup::Branch(pc, branch_type, size, cond));
if (label->IsBound()) {
// The branch is to a bound label which means that it's a backwards branch.
GetFixup(branch_id)->Resolve(label->Position());
Emit16(0);
} else {
// Branch target is an unbound label. Add it to a singly-linked list maintained within
// the code with the label serving as the head.
Emit16(static_cast<uint16_t>(label->position_));
label->LinkTo(branch_id);
}
if (use32bit) {
Emit16(0);
}
DCHECK_EQ(buffer_.Size() - pc, GetFixup(branch_id)->GetSizeInBytes());
}
void Thumb2Assembler::Emit32Miscellaneous(uint8_t op1,
uint8_t op2,
uint32_t rest_encoding) {
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 | B23 |
op1 << 20 |
0xf << 12 |
B7 |
op2 << 4 |
rest_encoding;
Emit32(encoding);
}
void Thumb2Assembler::Emit16Miscellaneous(uint32_t rest_encoding) {
int16_t encoding = B15 | B13 | B12 |
rest_encoding;
Emit16(encoding);
}
void Thumb2Assembler::clz(Register rd, Register rm, Condition cond) {
CHECK_NE(rd, kNoRegister);
CHECK_NE(rm, kNoRegister);
CheckCondition(cond);
CHECK_NE(rd, PC);
CHECK_NE(rm, PC);
int32_t encoding =
static_cast<uint32_t>(rm) << 16 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(rm);
Emit32Miscellaneous(0b11, 0b00, encoding);
}
void Thumb2Assembler::movw(Register rd, uint16_t imm16, Condition cond) {
CheckCondition(cond);
// Always 32 bits, encoding T3. (Other encondings are called MOV, not MOVW.)
uint32_t imm4 = (imm16 >> 12) & 15U /* 0b1111 */;
uint32_t i = (imm16 >> 11) & 1U /* 0b1 */;
uint32_t imm3 = (imm16 >> 8) & 7U /* 0b111 */;
uint32_t imm8 = imm16 & 0xff;
int32_t encoding = B31 | B30 | B29 | B28 |
B25 | B22 |
static_cast<uint32_t>(rd) << 8 |
i << 26 |
imm4 << 16 |
imm3 << 12 |
imm8;
Emit32(encoding);
}
void Thumb2Assembler::movt(Register rd, uint16_t imm16, Condition cond) {
CheckCondition(cond);
// Always 32 bits.
uint32_t imm4 = (imm16 >> 12) & 15U /* 0b1111 */;
uint32_t i = (imm16 >> 11) & 1U /* 0b1 */;
uint32_t imm3 = (imm16 >> 8) & 7U /* 0b111 */;
uint32_t imm8 = imm16 & 0xff;
int32_t encoding = B31 | B30 | B29 | B28 |
B25 | B23 | B22 |
static_cast<uint32_t>(rd) << 8 |
i << 26 |
imm4 << 16 |
imm3 << 12 |
imm8;
Emit32(encoding);
}
void Thumb2Assembler::rbit(Register rd, Register rm, Condition cond) {
CHECK_NE(rd, kNoRegister);
CHECK_NE(rm, kNoRegister);
CheckCondition(cond);
CHECK_NE(rd, PC);
CHECK_NE(rm, PC);
CHECK_NE(rd, SP);
CHECK_NE(rm, SP);
int32_t encoding =
static_cast<uint32_t>(rm) << 16 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(rm);
Emit32Miscellaneous(0b01, 0b10, encoding);
}
void Thumb2Assembler::EmitReverseBytes(Register rd, Register rm,
uint32_t op) {
CHECK_NE(rd, kNoRegister);
CHECK_NE(rm, kNoRegister);
CHECK_NE(rd, PC);
CHECK_NE(rm, PC);
CHECK_NE(rd, SP);
CHECK_NE(rm, SP);
if (!IsHighRegister(rd) && !IsHighRegister(rm) && !force_32bit_) {
uint16_t t1_op = B11 | B9 | (op << 6);
int16_t encoding = t1_op |
static_cast<uint16_t>(rm) << 3 |
static_cast<uint16_t>(rd);
Emit16Miscellaneous(encoding);
} else {
int32_t encoding =
static_cast<uint32_t>(rm) << 16 |
static_cast<uint32_t>(rd) << 8 |
static_cast<uint32_t>(rm);
Emit32Miscellaneous(0b01, op, encoding);
}
}
void Thumb2Assembler::rev(Register rd, Register rm, Condition cond) {
CheckCondition(cond);
EmitReverseBytes(rd, rm, 0b00);
}
void Thumb2Assembler::rev16(Register rd, Register rm, Condition cond) {
CheckCondition(cond);
EmitReverseBytes(rd, rm, 0b01);
}
void Thumb2Assembler::revsh(Register rd, Register rm, Condition cond) {
CheckCondition(cond);
EmitReverseBytes(rd, rm, 0b11);
}
void Thumb2Assembler::ldrex(Register rt, Register rn, uint16_t imm, Condition cond) {
CHECK_NE(rn, kNoRegister);
CHECK_NE(rt, kNoRegister);
CheckCondition(cond);
CHECK_LT(imm, (1u << 10));
int32_t encoding = B31 | B30 | B29 | B27 | B22 | B20 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rt) << 12 |
0xf << 8 |
imm >> 2;
Emit32(encoding);
}
void Thumb2Assembler::ldrex(Register rt, Register rn, Condition cond) {
ldrex(rt, rn, 0, cond);
}
void Thumb2Assembler::strex(Register rd,
Register rt,
Register rn,
uint16_t imm,
Condition cond) {
CHECK_NE(rn, kNoRegister);
CHECK_NE(rd, kNoRegister);
CHECK_NE(rt, kNoRegister);
CheckCondition(cond);
CHECK_LT(imm, (1u << 10));
int32_t encoding = B31 | B30 | B29 | B27 | B22 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rt) << 12 |
static_cast<uint32_t>(rd) << 8 |
imm >> 2;
Emit32(encoding);
}
void Thumb2Assembler::ldrexd(Register rt, Register rt2, Register rn, Condition cond) {
CHECK_NE(rn, kNoRegister);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt2, kNoRegister);
CHECK_NE(rt, rt2);
CheckCondition(cond);
int32_t encoding = B31 | B30 | B29 | B27 | B23 | B22 | B20 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rt) << 12 |
static_cast<uint32_t>(rt2) << 8 |
B6 | B5 | B4 | B3 | B2 | B1 | B0;
Emit32(encoding);
}
void Thumb2Assembler::strex(Register rd,
Register rt,
Register rn,
Condition cond) {
strex(rd, rt, rn, 0, cond);
}
void Thumb2Assembler::strexd(Register rd, Register rt, Register rt2, Register rn, Condition cond) {
CHECK_NE(rd, kNoRegister);
CHECK_NE(rn, kNoRegister);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt2, kNoRegister);
CHECK_NE(rt, rt2);
CHECK_NE(rd, rt);
CHECK_NE(rd, rt2);
CheckCondition(cond);
int32_t encoding = B31 | B30 | B29 | B27 | B23 | B22 |
static_cast<uint32_t>(rn) << 16 |
static_cast<uint32_t>(rt) << 12 |
static_cast<uint32_t>(rt2) << 8 |
B6 | B5 | B4 |
static_cast<uint32_t>(rd);
Emit32(encoding);
}
void Thumb2Assembler::clrex(Condition cond) {
CheckCondition(cond);
int32_t encoding = B31 | B30 | B29 | B27 | B28 | B25 | B24 | B23 |
B21 | B20 |
0xf << 16 |
B15 |
0xf << 8 |
B5 |
0xf;
Emit32(encoding);
}
void Thumb2Assembler::nop(Condition cond) {
CheckCondition(cond);
uint16_t encoding = B15 | B13 | B12 |
B11 | B10 | B9 | B8;
Emit16(static_cast<int16_t>(encoding));
}
void Thumb2Assembler::vmovsr(SRegister sn, Register rt, Condition cond) {
CHECK_NE(sn, kNoSRegister);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt, SP);
CHECK_NE(rt, PC);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 |
((static_cast<int32_t>(sn) >> 1)*B16) |
(static_cast<int32_t>(rt)*B12) | B11 | B9 |
((static_cast<int32_t>(sn) & 1)*B7) | B4;
Emit32(encoding);
}
void Thumb2Assembler::vmovrs(Register rt, SRegister sn, Condition cond) {
CHECK_NE(sn, kNoSRegister);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt, SP);
CHECK_NE(rt, PC);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 | B20 |
((static_cast<int32_t>(sn) >> 1)*B16) |
(static_cast<int32_t>(rt)*B12) | B11 | B9 |
((static_cast<int32_t>(sn) & 1)*B7) | B4;
Emit32(encoding);
}
void Thumb2Assembler::vmovsrr(SRegister sm, Register rt, Register rt2,
Condition cond) {
CHECK_NE(sm, kNoSRegister);
CHECK_NE(sm, S31);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt, SP);
CHECK_NE(rt, PC);
CHECK_NE(rt2, kNoRegister);
CHECK_NE(rt2, SP);
CHECK_NE(rt2, PC);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B22 |
(static_cast<int32_t>(rt2)*B16) |
(static_cast<int32_t>(rt)*B12) | B11 | B9 |
((static_cast<int32_t>(sm) & 1)*B5) | B4 |
(static_cast<int32_t>(sm) >> 1);
Emit32(encoding);
}
void Thumb2Assembler::vmovrrs(Register rt, Register rt2, SRegister sm,
Condition cond) {
CHECK_NE(sm, kNoSRegister);
CHECK_NE(sm, S31);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt, SP);
CHECK_NE(rt, PC);
CHECK_NE(rt2, kNoRegister);
CHECK_NE(rt2, SP);
CHECK_NE(rt2, PC);
CHECK_NE(rt, rt2);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B22 | B20 |
(static_cast<int32_t>(rt2)*B16) |
(static_cast<int32_t>(rt)*B12) | B11 | B9 |
((static_cast<int32_t>(sm) & 1)*B5) | B4 |
(static_cast<int32_t>(sm) >> 1);
Emit32(encoding);
}
void Thumb2Assembler::vmovdrr(DRegister dm, Register rt, Register rt2,
Condition cond) {
CHECK_NE(dm, kNoDRegister);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt, SP);
CHECK_NE(rt, PC);
CHECK_NE(rt2, kNoRegister);
CHECK_NE(rt2, SP);
CHECK_NE(rt2, PC);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B22 |
(static_cast<int32_t>(rt2)*B16) |
(static_cast<int32_t>(rt)*B12) | B11 | B9 | B8 |
((static_cast<int32_t>(dm) >> 4)*B5) | B4 |
(static_cast<int32_t>(dm) & 0xf);
Emit32(encoding);
}
void Thumb2Assembler::vmovrrd(Register rt, Register rt2, DRegister dm,
Condition cond) {
CHECK_NE(dm, kNoDRegister);
CHECK_NE(rt, kNoRegister);
CHECK_NE(rt, SP);
CHECK_NE(rt, PC);
CHECK_NE(rt2, kNoRegister);
CHECK_NE(rt2, SP);
CHECK_NE(rt2, PC);
CHECK_NE(rt, rt2);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B22 | B20 |
(static_cast<int32_t>(rt2)*B16) |
(static_cast<int32_t>(rt)*B12) | B11 | B9 | B8 |
((static_cast<int32_t>(dm) >> 4)*B5) | B4 |
(static_cast<int32_t>(dm) & 0xf);
Emit32(encoding);
}
void Thumb2Assembler::vldrs(SRegister sd, const Address& ad, Condition cond) {
const Address& addr = static_cast<const Address&>(ad);
CHECK_NE(sd, kNoSRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B24 | B20 |
((static_cast<int32_t>(sd) & 1)*B22) |
((static_cast<int32_t>(sd) >> 1)*B12) |
B11 | B9 | addr.vencoding();
Emit32(encoding);
}
void Thumb2Assembler::vstrs(SRegister sd, const Address& ad, Condition cond) {
const Address& addr = static_cast<const Address&>(ad);
CHECK_NE(static_cast<Register>(addr.encodingArm() & (0xf << kRnShift)), PC);
CHECK_NE(sd, kNoSRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B24 |
((static_cast<int32_t>(sd) & 1)*B22) |
((static_cast<int32_t>(sd) >> 1)*B12) |
B11 | B9 | addr.vencoding();
Emit32(encoding);
}
void Thumb2Assembler::vldrd(DRegister dd, const Address& ad, Condition cond) {
const Address& addr = static_cast<const Address&>(ad);
CHECK_NE(dd, kNoDRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B24 | B20 |
((static_cast<int32_t>(dd) >> 4)*B22) |
((static_cast<int32_t>(dd) & 0xf)*B12) |
B11 | B9 | B8 | addr.vencoding();
Emit32(encoding);
}
void Thumb2Assembler::vstrd(DRegister dd, const Address& ad, Condition cond) {
const Address& addr = static_cast<const Address&>(ad);
CHECK_NE(static_cast<Register>(addr.encodingArm() & (0xf << kRnShift)), PC);
CHECK_NE(dd, kNoDRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B24 |
((static_cast<int32_t>(dd) >> 4)*B22) |
((static_cast<int32_t>(dd) & 0xf)*B12) |
B11 | B9 | B8 | addr.vencoding();
Emit32(encoding);
}
void Thumb2Assembler::vpushs(SRegister reg, int nregs, Condition cond) {
EmitVPushPop(static_cast<uint32_t>(reg), nregs, true, false, cond);
}
void Thumb2Assembler::vpushd(DRegister reg, int nregs, Condition cond) {
EmitVPushPop(static_cast<uint32_t>(reg), nregs, true, true, cond);
}
void Thumb2Assembler::vpops(SRegister reg, int nregs, Condition cond) {
EmitVPushPop(static_cast<uint32_t>(reg), nregs, false, false, cond);
}
void Thumb2Assembler::vpopd(DRegister reg, int nregs, Condition cond) {
EmitVPushPop(static_cast<uint32_t>(reg), nregs, false, true, cond);
}
void Thumb2Assembler::EmitVPushPop(uint32_t reg, int nregs, bool push, bool dbl, Condition cond) {
CheckCondition(cond);
uint32_t D;
uint32_t Vd;
if (dbl) {
// Encoded as D:Vd.
D = (reg >> 4) & 1;
Vd = reg & 15U /* 0b1111 */;
} else {
// Encoded as Vd:D.
D = reg & 1;
Vd = (reg >> 1) & 15U /* 0b1111 */;
}
int32_t encoding = B27 | B26 | B21 | B19 | B18 | B16 |
B11 | B9 |
(dbl ? B8 : 0) |
(push ? B24 : (B23 | B20)) |
14U /* 0b1110 */ << 28 |
nregs << (dbl ? 1 : 0) |
D << 22 |
Vd << 12;
Emit32(encoding);
}
void Thumb2Assembler::EmitVFPsss(Condition cond, int32_t opcode,
SRegister sd, SRegister sn, SRegister sm) {
CHECK_NE(sd, kNoSRegister);
CHECK_NE(sn, kNoSRegister);
CHECK_NE(sm, kNoSRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 | B11 | B9 | opcode |
((static_cast<int32_t>(sd) & 1)*B22) |
((static_cast<int32_t>(sn) >> 1)*B16) |
((static_cast<int32_t>(sd) >> 1)*B12) |
((static_cast<int32_t>(sn) & 1)*B7) |
((static_cast<int32_t>(sm) & 1)*B5) |
(static_cast<int32_t>(sm) >> 1);
Emit32(encoding);
}
void Thumb2Assembler::EmitVFPddd(Condition cond, int32_t opcode,
DRegister dd, DRegister dn, DRegister dm) {
CHECK_NE(dd, kNoDRegister);
CHECK_NE(dn, kNoDRegister);
CHECK_NE(dm, kNoDRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 | B11 | B9 | B8 | opcode |
((static_cast<int32_t>(dd) >> 4)*B22) |
((static_cast<int32_t>(dn) & 0xf)*B16) |
((static_cast<int32_t>(dd) & 0xf)*B12) |
((static_cast<int32_t>(dn) >> 4)*B7) |
((static_cast<int32_t>(dm) >> 4)*B5) |
(static_cast<int32_t>(dm) & 0xf);
Emit32(encoding);
}
void Thumb2Assembler::EmitVFPsd(Condition cond, int32_t opcode,
SRegister sd, DRegister dm) {
CHECK_NE(sd, kNoSRegister);
CHECK_NE(dm, kNoDRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 | B11 | B9 | opcode |
((static_cast<int32_t>(sd) & 1)*B22) |
((static_cast<int32_t>(sd) >> 1)*B12) |
((static_cast<int32_t>(dm) >> 4)*B5) |
(static_cast<int32_t>(dm) & 0xf);
Emit32(encoding);
}
void Thumb2Assembler::EmitVFPds(Condition cond, int32_t opcode,
DRegister dd, SRegister sm) {
CHECK_NE(dd, kNoDRegister);
CHECK_NE(sm, kNoSRegister);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 | B11 | B9 | opcode |
((static_cast<int32_t>(dd) >> 4)*B22) |
((static_cast<int32_t>(dd) & 0xf)*B12) |
((static_cast<int32_t>(sm) & 1)*B5) |
(static_cast<int32_t>(sm) >> 1);
Emit32(encoding);
}
void Thumb2Assembler::vmstat(Condition cond) { // VMRS APSR_nzcv, FPSCR.
CHECK_NE(cond, kNoCondition);
CheckCondition(cond);
int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
B27 | B26 | B25 | B23 | B22 | B21 | B20 | B16 |
(static_cast<int32_t>(PC)*B12) |
B11 | B9 | B4;
Emit32(encoding);
}
void Thumb2Assembler::svc(uint32_t imm8) {
CHECK(IsUint<8>(imm8)) << imm8;
int16_t encoding = B15 | B14 | B12 |
B11 | B10 | B9 | B8 |
imm8;
Emit16(encoding);
}
void Thumb2Assembler::bkpt(uint16_t imm8) {
CHECK(IsUint<8>(imm8)) << imm8;
int16_t encoding = B15 | B13 | B12 |
B11 | B10 | B9 |
imm8;
Emit16(encoding);
}
// Convert the given IT state to a mask bit given bit 0 of the first
// condition and a shift position.
static uint8_t ToItMask(ItState s, uint8_t firstcond0, uint8_t shift) {
switch (s) {
case kItOmitted: return 1 << shift;
case kItThen: return firstcond0 << shift;
case kItElse: return !firstcond0 << shift;
}
return 0;
}
// Set the IT condition in the given position for the given state. This is used
// to check that conditional instructions match the preceding IT statement.
void Thumb2Assembler::SetItCondition(ItState s, Condition cond, uint8_t index) {
switch (s) {
case kItOmitted: it_conditions_[index] = AL; break;
case kItThen: it_conditions_[index] = cond; break;
case kItElse:
it_conditions_[index] = static_cast<Condition>(static_cast<uint8_t>(cond) ^ 1);
break;
}
}
void Thumb2Assembler::it(Condition firstcond, ItState i1, ItState i2, ItState i3) {
CheckCondition(AL); // Not allowed in IT block.
uint8_t firstcond0 = static_cast<uint8_t>(firstcond) & 1;
// All conditions to AL.
for (uint8_t i = 0; i < 4; ++i) {
it_conditions_[i] = AL;
}
SetItCondition(kItThen, firstcond, 0);
uint8_t mask = ToItMask(i1, firstcond0, 3);
SetItCondition(i1, firstcond, 1);
if (i1 != kItOmitted) {
mask |= ToItMask(i2, firstcond0, 2);
SetItCondition(i2, firstcond, 2);
if (i2 != kItOmitted) {
mask |= ToItMask(i3, firstcond0, 1);
SetItCondition(i3, firstcond, 3);
if (i3 != kItOmitted) {
mask |= 1U /* 0b0001 */;
}
}
}
// Start at first condition.
it_cond_index_ = 0;
next_condition_ = it_conditions_[0];
uint16_t encoding = B15 | B13 | B12 |
B11 | B10 | B9 | B8 |
firstcond << 4 |
mask;
Emit16(encoding);
}
void Thumb2Assembler::cbz(Register rn, Label* label) {
CheckCondition(AL);
if (label->IsBound()) {
LOG(FATAL) << "cbz can only be used to branch forwards";
UNREACHABLE();
} else if (IsHighRegister(rn)) {
LOG(FATAL) << "cbz can only be used with low registers";
UNREACHABLE();
} else {
uint16_t branchid = EmitCompareAndBranch(rn, static_cast<uint16_t>(label->position_), false);
label->LinkTo(branchid);
}
}
void Thumb2Assembler::cbnz(Register rn, Label* label) {
CheckCondition(AL);
if (label->IsBound()) {
LOG(FATAL) << "cbnz can only be used to branch forwards";
UNREACHABLE();
} else if (IsHighRegister(rn)) {
LOG(FATAL) << "cbnz can only be used with low registers";
UNREACHABLE();
} else {
uint16_t branchid = EmitCompareAndBranch(rn, static_cast<uint16_t>(label->position_), true);
label->LinkTo(branchid);
}
}
void Thumb2Assembler::blx(Register rm, Condition cond) {
CHECK_NE(rm, kNoRegister);
CheckCondition(cond);
int16_t encoding = B14 | B10 | B9 | B8 | B7 | static_cast<int16_t>(rm) << 3;
Emit16(encoding);
}
void Thumb2Assembler::bx(Register rm, Condition cond) {
CHECK_NE(rm, kNoRegister);
CheckCondition(cond);
int16_t encoding = B14 | B10 | B9 | B8 | static_cast<int16_t>(rm) << 3;
Emit16(encoding);
}
void Thumb2Assembler::Push(Register rd, Condition cond) {
str(rd, Address(SP, -kRegisterSize, Address::PreIndex), cond);
}
void Thumb2Assembler::Pop(Register rd, Condition cond) {
ldr(rd, Address(SP, kRegisterSize, Address::PostIndex), cond);
}
void Thumb2Assembler::PushList(RegList regs, Condition cond) {
stm(DB_W, SP, regs, cond);
}
void Thumb2Assembler::PopList(RegList regs, Condition cond) {
ldm(IA_W, SP, regs, cond);
}
void Thumb2Assembler::Mov(Register rd, Register rm, Condition cond) {
if (cond != AL || rd != rm) {
mov(rd, ShifterOperand(rm), cond);
}
}
void Thumb2Assembler::Bind(Label* label) {
BindLabel(label, buffer_.Size());
}
void Thumb2Assembler::Lsl(Register rd, Register rm, uint32_t shift_imm,
Condition cond, SetCc set_cc) {
CHECK_LE(shift_imm, 31u);
CheckCondition(cond);
EmitShift(rd, rm, LSL, shift_imm, cond, set_cc);
}
void Thumb2Assembler::Lsr(Register rd, Register rm, uint32_t shift_imm,
Condition cond, SetCc set_cc) {
CHECK(1u <= shift_imm && shift_imm <= 32u);
if (shift_imm == 32) shift_imm = 0; // Comply to UAL syntax.
CheckCondition(cond);
EmitShift(rd, rm, LSR, shift_imm, cond, set_cc);
}
void Thumb2Assembler::Asr(Register rd, Register rm, uint32_t shift_imm,
Condition cond, SetCc set_cc) {
CHECK(1u <= shift_imm && shift_imm <= 32u);
if (shift_imm == 32) shift_imm = 0; // Comply to UAL syntax.
CheckCondition(cond);
EmitShift(rd, rm, ASR, shift_imm, cond, set_cc);
}
void Thumb2Assembler::Ror(Register rd, Register rm, uint32_t shift_imm,
Condition cond, SetCc set_cc) {
CHECK(1u <= shift_imm && shift_imm <= 31u);
CheckCondition(cond);
EmitShift(rd, rm, ROR, shift_imm, cond, set_cc);
}
void Thumb2Assembler::Rrx(Register rd, Register rm, Condition cond, SetCc set_cc) {
CheckCondition(cond);
EmitShift(rd, rm, RRX, 0, cond, set_cc);
}
void Thumb2Assembler::Lsl(Register rd, Register rm, Register rn,
Condition cond, SetCc set_cc) {
CheckCondition(cond);
EmitShift(rd, rm, LSL, rn, cond, set_cc);
}
void Thumb2Assembler::Lsr(Register rd, Register rm, Register rn,
Condition cond, SetCc set_cc) {
CheckCondition(cond);
EmitShift(rd, rm, LSR, rn, cond, set_cc);
}
void Thumb2Assembler::Asr(Register rd, Register rm, Register rn,
Condition cond, SetCc set_cc) {
CheckCondition(cond);
EmitShift(rd, rm, ASR, rn, cond, set_cc);
}
void Thumb2Assembler::Ror(Register rd, Register rm, Register rn,
Condition cond, SetCc set_cc) {
CheckCondition(cond);
EmitShift(rd, rm, ROR, rn, cond, set_cc);
}
int32_t Thumb2Assembler::EncodeBranchOffset(int32_t offset, int32_t inst) {
// The offset is off by 4 due to the way the ARM CPUs read PC.
offset -= 4;
offset >>= 1;
uint32_t value = 0;
// There are two different encodings depending on the value of bit 12. In one case
// intermediate values are calculated using the sign bit.
if ((inst & B12) == B12) {
// 25 bits of offset.
uint32_t signbit = (offset >> 31) & 0x1;
uint32_t i1 = (offset >> 22) & 0x1;
uint32_t i2 = (offset >> 21) & 0x1;
uint32_t imm10 = (offset >> 11) & 0x03ff;
uint32_t imm11 = offset & 0x07ff;
uint32_t j1 = (i1 ^ signbit) ? 0 : 1;
uint32_t j2 = (i2 ^ signbit) ? 0 : 1;
value = (signbit << 26) | (j1 << 13) | (j2 << 11) | (imm10 << 16) |
imm11;
// Remove the offset from the current encoding.
inst &= ~(0x3ff << 16 | 0x7ff);
} else {
uint32_t signbit = (offset >> 31) & 0x1;
uint32_t imm6 = (offset >> 11) & 0x03f;
uint32_t imm11 = offset & 0x07ff;
uint32_t j1 = (offset >> 19) & 1;
uint32_t j2 = (offset >> 17) & 1;
value = (signbit << 26) | (j1 << 13) | (j2 << 11) | (imm6 << 16) |
imm11;
// Remove the offset from the current encoding.
inst &= ~(0x3f << 16 | 0x7ff);
}
// Mask out offset bits in current instruction.
inst &= ~(B26 | B13 | B11);
inst |= value;
return inst;
}
int Thumb2Assembler::DecodeBranchOffset(int32_t instr) {
int32_t imm32;
if ((instr & B12) == B12) {
uint32_t S = (instr >> 26) & 1;
uint32_t J2 = (instr >> 11) & 1;
uint32_t J1 = (instr >> 13) & 1;
uint32_t imm10 = (instr >> 16) & 0x3FF;
uint32_t imm11 = instr & 0x7FF;
uint32_t I1 = ~(J1 ^ S) & 1;
uint32_t I2 = ~(J2 ^ S) & 1;
imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
imm32 = (imm32 << 8) >> 8; // sign extend 24 bit immediate.
} else {
uint32_t S = (instr >> 26) & 1;
uint32_t J2 = (instr >> 11) & 1;
uint32_t J1 = (instr >> 13) & 1;
uint32_t imm6 = (instr >> 16) & 0x3F;
uint32_t imm11 = instr & 0x7FF;
imm32 = (S << 20) | (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
imm32 = (imm32 << 11) >> 11; // sign extend 21 bit immediate.
}
imm32 += 4;
return imm32;
}
uint32_t Thumb2Assembler::GetAdjustedPosition(uint32_t old_position) {
// We can reconstruct the adjustment by going through all the fixups from the beginning
// up to the old_position. Since we expect AdjustedPosition() to be called in a loop
// with increasing old_position, we can use the data from last AdjustedPosition() to
// continue where we left off and the whole loop should be O(m+n) where m is the number
// of positions to adjust and n is the number of fixups.
if (old_position < last_old_position_) {
last_position_adjustment_ = 0u;
last_old_position_ = 0u;
last_fixup_id_ = 0u;
}
while (last_fixup_id_ != fixups_.size()) {
Fixup* fixup = GetFixup(last_fixup_id_);
if (fixup->GetLocation() >= old_position + last_position_adjustment_) {
break;
}
if (fixup->GetSize() != fixup->GetOriginalSize()) {
last_position_adjustment_ += fixup->GetSizeInBytes() - fixup->GetOriginalSizeInBytes();
}
++last_fixup_id_;
}
last_old_position_ = old_position;
return old_position + last_position_adjustment_;
}
Literal* Thumb2Assembler::NewLiteral(size_t size, const uint8_t* data) {
DCHECK(size == 4u || size == 8u) << size;
literals_.emplace_back(size, data);
return &literals_.back();
}
void Thumb2Assembler::LoadLiteral(Register rt, Literal* literal) {
DCHECK_EQ(literal->GetSize(), 4u);
DCHECK(!literal->GetLabel()->IsBound());
bool use32bit = IsForced32Bit() || IsHighRegister(rt);
uint32_t location = buffer_.Size();
Fixup::Size size = use32bit ? Fixup::kLiteral4KiB : Fixup::kLiteral1KiB;
FixupId fixup_id = AddFixup(Fixup::LoadNarrowLiteral(location, rt, size));
Emit16(static_cast<uint16_t>(literal->GetLabel()->position_));
literal->GetLabel()->LinkTo(fixup_id);
if (use32bit) {
Emit16(0);
}
DCHECK_EQ(location + GetFixup(fixup_id)->GetSizeInBytes(), buffer_.Size());
}
void Thumb2Assembler::LoadLiteral(Register rt, Register rt2, Literal* literal) {
DCHECK_EQ(literal->GetSize(), 8u);
DCHECK(!literal->GetLabel()->IsBound());
uint32_t location = buffer_.Size();
FixupId fixup_id =
AddFixup(Fixup::LoadWideLiteral(location, rt, rt2, Fixup::kLongOrFPLiteral1KiB));
Emit16(static_cast<uint16_t>(literal->GetLabel()->position_));
literal->GetLabel()->LinkTo(fixup_id);
Emit16(0);
DCHECK_EQ(location + GetFixup(fixup_id)->GetSizeInBytes(), buffer_.Size());
}
void Thumb2Assembler::LoadLiteral(SRegister sd, Literal* literal) {
DCHECK_EQ(literal->GetSize(), 4u);
DCHECK(!literal->GetLabel()->IsBound());
uint32_t location = buffer_.Size();
FixupId fixup_id = AddFixup(Fixup::LoadSingleLiteral(location, sd, Fixup::kLongOrFPLiteral1KiB));
Emit16(static_cast<uint16_t>(literal->GetLabel()->position_));
literal->GetLabel()->LinkTo(fixup_id);
Emit16(0);
DCHECK_EQ(location + GetFixup(fixup_id)->GetSizeInBytes(), buffer_.Size());
}
void Thumb2Assembler::LoadLiteral(DRegister dd, Literal* literal) {
DCHECK_EQ(literal->GetSize(), 8u);
DCHECK(!literal->GetLabel()->IsBound());
uint32_t location = buffer_.Size();
FixupId fixup_id = AddFixup(Fixup::LoadDoubleLiteral(location, dd, Fixup::kLongOrFPLiteral1KiB));
Emit16(static_cast<uint16_t>(literal->GetLabel()->position_));
literal->GetLabel()->LinkTo(fixup_id);
Emit16(0);
DCHECK_EQ(location + GetFixup(fixup_id)->GetSizeInBytes(), buffer_.Size());
}
void Thumb2Assembler::AddConstant(Register rd, Register rn, int32_t value,
Condition cond, SetCc set_cc) {
if (value == 0 && set_cc != kCcSet) {
if (rd != rn) {
mov(rd, ShifterOperand(rn), cond);
}
return;
}
// We prefer to select the shorter code sequence rather than selecting add for
// positive values and sub for negatives ones, which would slightly improve
// the readability of generated code for some constants.
ShifterOperand shifter_op;
if (ShifterOperandCanHold(rd, rn, ADD, value, set_cc, &shifter_op)) {
add(rd, rn, shifter_op, cond, set_cc);
} else if (ShifterOperandCanHold(rd, rn, SUB, -value, set_cc, &shifter_op)) {
sub(rd, rn, shifter_op, cond, set_cc);
} else {
CHECK(rn != IP);
// If rd != rn, use rd as temp. This alows 16-bit ADD/SUB in more situations than using IP.
Register temp = (rd != rn) ? rd : IP;
if (ShifterOperandCanHold(temp, kNoRegister, MVN, ~value, kCcKeep, &shifter_op)) {
mvn(temp, shifter_op, cond, kCcKeep);
add(rd, rn, ShifterOperand(temp), cond, set_cc);
} else if (ShifterOperandCanHold(temp, kNoRegister, MVN, ~(-value), kCcKeep, &shifter_op)) {
mvn(temp, shifter_op, cond, kCcKeep);
sub(rd, rn, ShifterOperand(temp), cond, set_cc);
} else if (High16Bits(-value) == 0) {
movw(temp, Low16Bits(-value), cond);
sub(rd, rn, ShifterOperand(temp), cond, set_cc);
} else {
movw(temp, Low16Bits(value), cond);
uint16_t value_high = High16Bits(value);
if (value_high != 0) {
movt(temp, value_high, cond);
}
add(rd, rn, ShifterOperand(temp), cond, set_cc);
}
}
}
void Thumb2Assembler::CmpConstant(Register rn, int32_t value, Condition cond) {
// We prefer to select the shorter code sequence rather than using plain cmp and cmn
// which would slightly improve the readability of generated code for some constants.
ShifterOperand shifter_op;
if (ShifterOperandCanHold(kNoRegister, rn, CMP, value, kCcSet, &shifter_op)) {
cmp(rn, shifter_op, cond);
} else if (ShifterOperandCanHold(kNoRegister, rn, CMN, -value, kCcSet, &shifter_op)) {
cmn(rn, shifter_op, cond);
} else {
CHECK(rn != IP);
if (ShifterOperandCanHold(IP, kNoRegister, MVN, ~value, kCcKeep, &shifter_op)) {
mvn(IP, shifter_op, cond, kCcKeep);
cmp(rn, ShifterOperand(IP), cond);
} else if (ShifterOperandCanHold(IP, kNoRegister, MVN, ~(-value), kCcKeep, &shifter_op)) {
mvn(IP, shifter_op, cond, kCcKeep);
cmn(rn, ShifterOperand(IP), cond);
} else if (High16Bits(-value) == 0) {
movw(IP, Low16Bits(-value), cond);
cmn(rn, ShifterOperand(IP), cond);
} else {
movw(IP, Low16Bits(value), cond);
uint16_t value_high = High16Bits(value);
if (value_high != 0) {
movt(IP, value_high, cond);
}
cmp(rn, ShifterOperand(IP), cond);
}
}
}
void Thumb2Assembler::LoadImmediate(Register rd, int32_t value, Condition cond) {
ShifterOperand shifter_op;
if (ShifterOperandCanHold(rd, R0, MOV, value, &shifter_op)) {
mov(rd, shifter_op, cond);
} else if (ShifterOperandCanHold(rd, R0, MVN, ~value, &shifter_op)) {
mvn(rd, shifter_op, cond);
} else {
movw(rd, Low16Bits(value), cond);
uint16_t value_high = High16Bits(value);
if (value_high != 0) {
movt(rd, value_high, cond);
}
}
}
int32_t Thumb2Assembler::GetAllowedLoadOffsetBits(LoadOperandType type) {
switch (type) {
case kLoadSignedByte:
case kLoadSignedHalfword:
case kLoadUnsignedHalfword:
case kLoadUnsignedByte:
case kLoadWord:
// We can encode imm12 offset.
return 0xfffu;
case kLoadSWord:
case kLoadDWord:
case kLoadWordPair:
// We can encode imm8:'00' offset.
return 0xff << 2;
default:
LOG(FATAL) << "UNREACHABLE";
UNREACHABLE();
}
}
int32_t Thumb2Assembler::GetAllowedStoreOffsetBits(StoreOperandType type) {
switch (type) {
case kStoreHalfword:
case kStoreByte:
case kStoreWord:
// We can encode imm12 offset.
return 0xfff;
case kStoreSWord:
case kStoreDWord:
case kStoreWordPair:
// We can encode imm8:'00' offset.
return 0xff << 2;
default:
LOG(FATAL) << "UNREACHABLE";
UNREACHABLE();
}
}
bool Thumb2Assembler::CanSplitLoadStoreOffset(int32_t allowed_offset_bits,
int32_t offset,
/*out*/ int32_t* add_to_base,
/*out*/ int32_t* offset_for_load_store) {
int32_t other_bits = offset & ~allowed_offset_bits;
if (ShifterOperandCanAlwaysHold(other_bits) || ShifterOperandCanAlwaysHold(-other_bits)) {
*add_to_base = offset & ~allowed_offset_bits;
*offset_for_load_store = offset & allowed_offset_bits;
return true;
}
return false;
}
int32_t Thumb2Assembler::AdjustLoadStoreOffset(int32_t allowed_offset_bits,
Register temp,
Register base,
int32_t offset,
Condition cond) {
DCHECK_NE(offset & ~allowed_offset_bits, 0);
int32_t add_to_base, offset_for_load;
if (CanSplitLoadStoreOffset(allowed_offset_bits, offset, &add_to_base, &offset_for_load)) {
AddConstant(temp, base, add_to_base, cond, kCcKeep);
return offset_for_load;
} else {
LoadImmediate(temp, offset, cond);
add(temp, temp, ShifterOperand(base), cond, kCcKeep);
return 0;
}
}
// Implementation note: this method must emit at most one instruction when
// Address::CanHoldLoadOffsetThumb.
void Thumb2Assembler::LoadFromOffset(LoadOperandType type,
Register reg,
Register base,
int32_t offset,
Condition cond) {
if (!Address::CanHoldLoadOffsetThumb(type, offset)) {
CHECK_NE(base, IP);
// Inlined AdjustLoadStoreOffset() allows us to pull a few more tricks.
int32_t allowed_offset_bits = GetAllowedLoadOffsetBits(type);
DCHECK_NE(offset & ~allowed_offset_bits, 0);
int32_t add_to_base, offset_for_load;
if (CanSplitLoadStoreOffset(allowed_offset_bits, offset, &add_to_base, &offset_for_load)) {
// Use reg for the adjusted base. If it's low reg, we may end up using 16-bit load.
AddConstant(reg, base, add_to_base, cond, kCcKeep);
base = reg;
offset = offset_for_load;
} else {
Register temp = (reg == base) ? IP : reg;
LoadImmediate(temp, offset, cond);
// TODO: Implement indexed load (not available for LDRD) and use it here to avoid the ADD.
// Use reg for the adjusted base. If it's low reg, we may end up using 16-bit load.
add(reg, reg, ShifterOperand((reg == base) ? IP : base), cond, kCcKeep);
base = reg;
offset = 0;
}
}
DCHECK(Address::CanHoldLoadOffsetThumb(type, offset));
switch (type) {
case kLoadSignedByte:
ldrsb(reg, Address(base, offset), cond);
break;
case kLoadUnsignedByte:
ldrb(reg, Address(base, offset), cond);
break;
case kLoadSignedHalfword:
ldrsh(reg, Address(base, offset), cond);
break;
case kLoadUnsignedHalfword:
ldrh(reg, Address(base, offset), cond);
break;
case kLoadWord:
ldr(reg, Address(base, offset), cond);
break;
case kLoadWordPair:
ldrd(reg, Address(base, offset), cond);
break;
default:
LOG(FATAL) << "UNREACHABLE";
UNREACHABLE();
}
}
// Implementation note: this method must emit at most one instruction when
// Address::CanHoldLoadOffsetThumb, as expected by JIT::GuardedLoadFromOffset.
void Thumb2Assembler::LoadSFromOffset(SRegister reg,
Register base,
int32_t offset,
Condition cond) {
if (!Address::CanHoldLoadOffsetThumb(kLoadSWord, offset)) {
CHECK_NE(base, IP);
offset = AdjustLoadStoreOffset(GetAllowedLoadOffsetBits(kLoadSWord), IP, base, offset, cond);
base = IP;
}
DCHECK(Address::CanHoldLoadOffsetThumb(kLoadSWord, offset));
vldrs(reg, Address(base, offset), cond);
}
// Implementation note: this method must emit at most one instruction when
// Address::CanHoldLoadOffsetThumb, as expected by JIT::GuardedLoadFromOffset.
void Thumb2Assembler::LoadDFromOffset(DRegister reg,
Register base,
int32_t offset,
Condition cond) {
if (!Address::CanHoldLoadOffsetThumb(kLoadDWord, offset)) {
CHECK_NE(base, IP);
offset = AdjustLoadStoreOffset(GetAllowedLoadOffsetBits(kLoadDWord), IP, base, offset, cond);
base = IP;
}
DCHECK(Address::CanHoldLoadOffsetThumb(kLoadDWord, offset));
vldrd(reg, Address(base, offset), cond);
}
// Implementation note: this method must emit at most one instruction when
// Address::CanHoldStoreOffsetThumb.
void Thumb2Assembler::StoreToOffset(StoreOperandType type,
Register reg,
Register base,
int32_t offset,
Condition cond) {
Register tmp_reg = kNoRegister;
if (!Address::CanHoldStoreOffsetThumb(type, offset)) {
CHECK_NE(base, IP);
if ((reg != IP) &&
((type != kStoreWordPair) || (reg + 1 != IP))) {
tmp_reg = IP;
} else {
// Be careful not to use IP twice (for `reg` (or `reg` + 1 in
// the case of a word-pair store) and `base`) to build the
// Address object used by the store instruction(s) below.
// Instead, save R5 on the stack (or R6 if R5 is already used by
// `base`), use it as secondary temporary register, and restore
// it after the store instruction has been emitted.
tmp_reg = (base != R5) ? R5 : R6;
Push(tmp_reg);
if (base == SP) {
offset += kRegisterSize;
}
}
// TODO: Implement indexed store (not available for STRD), inline AdjustLoadStoreOffset()
// and in the "unsplittable" path get rid of the "add" by using the store indexed instead.
offset = AdjustLoadStoreOffset(GetAllowedStoreOffsetBits(type), tmp_reg, base, offset, cond);
base = tmp_reg;
}
DCHECK(Address::CanHoldStoreOffsetThumb(type, offset));
switch (type) {
case kStoreByte:
strb(reg, Address(base, offset), cond);
break;
case kStoreHalfword:
strh(reg, Address(base, offset), cond);
break;
case kStoreWord:
str(reg, Address(base, offset), cond);
break;
case kStoreWordPair:
strd(reg, Address(base, offset), cond);
break;
default:
LOG(FATAL) << "UNREACHABLE";
UNREACHABLE();
}
if ((tmp_reg != kNoRegister) && (tmp_reg != IP)) {
CHECK((tmp_reg == R5) || (tmp_reg == R6));
Pop(tmp_reg);
}
}
// Implementation note: this method must emit at most one instruction when
// Address::CanHoldStoreOffsetThumb, as expected by JIT::GuardedStoreToOffset.
void Thumb2Assembler::StoreSToOffset(SRegister reg,
Register base,
int32_t offset,
Condition cond) {
if (!Address::CanHoldStoreOffsetThumb(kStoreSWord, offset)) {
CHECK_NE(base, IP);
offset = AdjustLoadStoreOffset(GetAllowedStoreOffsetBits(kStoreSWord), IP, base, offset, cond);
base = IP;
}
DCHECK(Address::CanHoldStoreOffsetThumb(kStoreSWord, offset));
vstrs(reg, Address(base, offset), cond);
}
// Implementation note: this method must emit at most one instruction when
// Address::CanHoldStoreOffsetThumb, as expected by JIT::GuardedStoreSToOffset.
void Thumb2Assembler::StoreDToOffset(DRegister reg,
Register base,
int32_t offset,
Condition cond) {
if (!Address::CanHoldStoreOffsetThumb(kStoreDWord, offset)) {
CHECK_NE(base, IP);
offset = AdjustLoadStoreOffset(GetAllowedStoreOffsetBits(kStoreDWord), IP, base, offset, cond);
base = IP;
}
DCHECK(Address::CanHoldStoreOffsetThumb(kStoreDWord, offset));
vstrd(reg, Address(base, offset), cond);
}
void Thumb2Assembler::MemoryBarrier(ManagedRegister mscratch) {
CHECK_EQ(mscratch.AsArm().AsCoreRegister(), R12);
dmb(SY);
}
void Thumb2Assembler::dmb(DmbOptions flavor) {
int32_t encoding = 0xf3bf8f50; // dmb in T1 encoding.
Emit32(encoding | flavor);
}
void Thumb2Assembler::CompareAndBranchIfZero(Register r, Label* label) {
if (CanRelocateBranches() && IsLowRegister(r) && !label->IsBound()) {
cbz(r, label);
} else {
cmp(r, ShifterOperand(0));
b(label, EQ);
}
}
void Thumb2Assembler::CompareAndBranchIfNonZero(Register r, Label* label) {
if (CanRelocateBranches() && IsLowRegister(r) && !label->IsBound()) {
cbnz(r, label);
} else {
cmp(r, ShifterOperand(0));
b(label, NE);
}
}
JumpTable* Thumb2Assembler::CreateJumpTable(std::vector<Label*>&& labels, Register base_reg) {
jump_tables_.emplace_back(std::move(labels));
JumpTable* table = &jump_tables_.back();
DCHECK(!table->GetLabel()->IsBound());
bool use32bit = IsForced32Bit() || IsHighRegister(base_reg);
uint32_t location = buffer_.Size();
Fixup::Size size = use32bit ? Fixup::kLiteralAddr4KiB : Fixup::kLiteralAddr1KiB;
FixupId fixup_id = AddFixup(Fixup::LoadLiteralAddress(location, base_reg, size));
Emit16(static_cast<uint16_t>(table->GetLabel()->position_));
table->GetLabel()->LinkTo(fixup_id);
if (use32bit) {
Emit16(0);
}
DCHECK_EQ(location + GetFixup(fixup_id)->GetSizeInBytes(), buffer_.Size());
return table;
}
void Thumb2Assembler::EmitJumpTableDispatch(JumpTable* jump_table, Register displacement_reg) {
CHECK(!IsForced32Bit()) << "Forced 32-bit dispatch not implemented yet";
// 32-bit ADD doesn't support PC as an input, so we need a two-instruction sequence:
// SUB ip, ip, #0
// ADD pc, ip, reg
// TODO: Implement.
// The anchor's position needs to be fixed up before we can compute offsets - so make it a tracked
// label.
BindTrackedLabel(jump_table->GetAnchorLabel());
add(PC, PC, ShifterOperand(displacement_reg));
}
} // namespace arm
} // namespace art