blob: 78ff31a061b8d7d83706d11eca263968585b7d80 [file] [log] [blame]
/*
* 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 "assembler_thumb2.h"
#include "base/logging.h"
#include "entrypoints/quick/quick_entrypoints.h"
#include "offsets.h"
#include "thread.h"
#include "utils.h"
namespace art {
namespace arm {
void Thumb2Assembler::and_(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, AND, 0, rn, rd, so);
}
void Thumb2Assembler::eor(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, EOR, 0, rn, rd, so);
}
void Thumb2Assembler::sub(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, SUB, 0, rn, rd, so);
}
void Thumb2Assembler::rsb(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, RSB, 0, rn, rd, so);
}
void Thumb2Assembler::rsbs(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, RSB, 1, rn, rd, so);
}
void Thumb2Assembler::add(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, ADD, 0, rn, rd, so);
}
void Thumb2Assembler::adds(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, ADD, 1, rn, rd, so);
}
void Thumb2Assembler::subs(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, SUB, 1, rn, rd, so);
}
void Thumb2Assembler::adc(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, ADC, 0, rn, rd, so);
}
void Thumb2Assembler::sbc(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, SBC, 0, rn, rd, so);
}
void Thumb2Assembler::rsc(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, RSC, 0, 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, 1, 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, 1, rn, R0, so);
}
void Thumb2Assembler::cmp(Register rn, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, CMP, 1, rn, R0, so);
}
void Thumb2Assembler::cmn(Register rn, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, CMN, 1, rn, R0, so);
}
void Thumb2Assembler::orr(Register rd, Register rn,
const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, ORR, 0, rn, rd, so);
}
void Thumb2Assembler::orrs(Register rd, Register rn,
const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, ORR, 1, rn, rd, so);
}
void Thumb2Assembler::mov(Register rd, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, MOV, 0, R0, rd, so);
}
void Thumb2Assembler::movs(Register rd, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, MOV, 1, R0, rd, so);
}
void Thumb2Assembler::bic(Register rd, Register rn, const ShifterOperand& so,
Condition cond) {
EmitDataProcessing(cond, BIC, 0, rn, rd, so);
}
void Thumb2Assembler::mvn(Register rd, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, MVN, 0, R0, rd, so);
}
void Thumb2Assembler::mvns(Register rd, const ShifterOperand& so, Condition cond) {
EmitDataProcessing(cond, MVN, 1, R0, rd, so);
}
void Thumb2Assembler::mul(Register rd, Register rn, Register rm, Condition 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 = 0b000;
uint32_t op2 = 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) {
uint32_t op1 = 0b000;
uint32_t op2 = 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) {
uint32_t op1 = 0b000;
uint32_t op2 = 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::umull(Register rd_lo, Register rd_hi, Register rn,
Register rm, Condition cond) {
uint32_t op1 = 0b010;
uint32_t op2 = 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) {
uint32_t op1 = 0b001;
uint32_t op2 = 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) {
uint32_t op1 = 0b001;
uint32_t op2 = 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::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) {
CHECK_EQ(rd % 2, 0);
// 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>(rd) + 1) << 8 |
ad.encodingThumbLdrdStrd();
Emit32(encoding);
}
void Thumb2Assembler::strd(Register rd, const Address& ad, Condition cond) {
CHECK_EQ(rd % 2, 0);
// 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>(rd) + 1) << 8 |
ad.encodingThumbLdrdStrd();
Emit32(encoding);
}
void Thumb2Assembler::ldm(BlockAddressMode am,
Register base,
RegList regs,
Condition cond) {
if (__builtin_popcount(regs) == 1) {
// Thumb doesn't support one reg in the list.
// Find the register number.
int reg = 0;
while (reg < 16) {
if ((regs & (1 << reg)) != 0) {
break;
}
++reg;
}
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) {
if (__builtin_popcount(regs) == 1) {
// Thumb doesn't support one reg in the list.
// Find the register number.
int reg = 0;
while (reg < 16) {
if ((regs & (1 << reg)) != 0) {
break;
}
++reg;
}
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) {
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, 1, 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,
int set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
if (force_32bit_) {
return true;
}
bool can_contain_high_register = (opcode == MOV)
|| ((opcode == ADD || opcode == SUB) && (rn == rd));
if (IsHighRegister(rd) || IsHighRegister(rn)) {
if (can_contain_high_register) {
// There are high register instructions available for this opcode.
// However, there is no RRX available.
if (so.IsShift() && so.GetShift() == RRX) {
return true;
}
// Check special case for SP relative ADD and SUB immediate.
if ((opcode == ADD || opcode == SUB) && so.IsImmediate()) {
// If rn is SP and rd is a high register we need to use a 32 bit encoding.
if (rn == SP && rd != SP && IsHighRegister(rd)) {
return true;
}
uint32_t imm = so.GetImmediate();
// If the immediates are out of range use 32 bit.
if (rd == SP && rn == SP) {
if (imm > (1 << 9)) { // 9 bit immediate.
return true;
}
} else if (opcode == ADD && rd != SP && rn == SP) { // 10 bit immediate.
if (imm > (1 << 10)) {
return true;
}
} else if (opcode == SUB && rd != SP && rn == SP) {
// SUB rd, SP, #imm is always 32 bit.
return true;
}
}
}
// The ADD,SUB and MOV instructions that work with high registers don't have
// immediate variants.
if (so.IsImmediate()) {
return true;
}
}
if (so.IsRegister() && IsHighRegister(so.GetRegister()) && !can_contain_high_register) {
return true;
}
// Check for MOV with an ROR.
if (opcode == MOV && so.IsRegister() && so.IsShift() && so.GetShift() == ROR) {
if (so.GetImmediate() != 0) {
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:
return true;
break;
case ADD:
case SUB:
break;
default:
if (so.IsRegister() && rd != rn) {
return true;
}
}
if (so.IsImmediate()) {
if (rn_is_valid && rn != rd) {
// The only thumb1 instruction with a register and an immediate are ADD and SUB. The
// immediate must be 3 bits.
if (opcode != ADD && opcode != SUB) {
return true;
} else {
// Check that the immediate is 3 bits for ADD and SUB.
if (so.GetImmediate() >= 8) {
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 (so.GetImmediate() > 255) {
return true;
}
}
}
}
// The instruction can be encoded in 16 bits.
return false;
}
void Thumb2Assembler::Emit32BitDataProcessing(Condition cond,
Opcode opcode,
int set_cc,
Register rn,
Register rd,
const ShifterOperand& so) {
uint8_t thumb_opcode = 0b11111111;
switch (opcode) {
case AND: thumb_opcode = 0b0000; break;
case EOR: thumb_opcode = 0b0100; break;
case SUB: thumb_opcode = 0b1101; break;
case RSB: thumb_opcode = 0b1110; break;
case ADD: thumb_opcode = 0b1000; break;
case ADC: thumb_opcode = 0b1010; break;
case SBC: thumb_opcode = 0b1011; break;
case RSC: break;
case TST: thumb_opcode = 0b0000; set_cc = true; rd = PC; break;
case TEQ: thumb_opcode = 0b0100; set_cc = true; rd = PC; break;
case CMP: thumb_opcode = 0b1101; set_cc = true; rd = PC; break;
case CMN: thumb_opcode = 0b1000; set_cc = true; rd = PC; break;
case ORR: thumb_opcode = 0b0010; break;
case MOV: thumb_opcode = 0b0010; rn = PC; break;
case BIC: thumb_opcode = 0b0001; break;
case MVN: thumb_opcode = 0b0011; rn = PC; break;
default:
break;
}
if (thumb_opcode == 0b11111111) {
LOG(FATAL) << "Invalid thumb2 opcode " << opcode;
}
int32_t encoding = 0;
if (so.IsImmediate()) {
// Check special cases.
if ((opcode == SUB || opcode == ADD) && (so.GetImmediate() < (1u << 12))) {
if (opcode == SUB) {
thumb_opcode = 0b0101;
} else {
thumb_opcode = 0;
}
uint32_t imm = so.GetImmediate();
uint32_t i = (imm >> 11) & 1;
uint32_t imm3 = (imm >> 8) & 0b111;
uint32_t imm8 = imm & 0xff;
encoding = B31 | B30 | B29 | B28 | 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";
}
encoding = B31 | B30 | B29 | B28 |
thumb_opcode << 21 |
set_cc << 20 |
rn << 16 |
rd << 8 |
imm;
}
} else if (so.IsRegister()) {
// Register (possibly shifted)
encoding = B31 | B30 | B29 | B27 | B25 |
thumb_opcode << 21 |
set_cc << 20 |
rn << 16 |
rd << 8 |
so.encodingThumb();
}
Emit32(encoding);
}
void Thumb2Assembler::Emit16BitDataProcessing(Condition cond,
Opcode opcode,
int 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 = 0b11111111;
// Thumb1.
uint8_t dp_opcode = 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: thumb_opcode = 0b00; break;
case LSR: thumb_opcode = 0b01; break;
case ASR: thumb_opcode = 0b10; break;
case ROR:
// ROR doesn't allow immediates.
thumb_opcode = 0b111;
dp_opcode = 0b01;
opcode_shift = 6;
use_immediate = false;
break;
case RRX: break;
default:
break;
}
} else {
if (so.IsImmediate()) {
use_immediate = true;
immediate = so.GetImmediate();
}
switch (opcode) {
case AND: thumb_opcode = 0b0000; break;
case EOR: thumb_opcode = 0b0001; break;
case SUB: break;
case RSB: thumb_opcode = 0b1001; break;
case ADD: break;
case ADC: thumb_opcode = 0b0101; break;
case SBC: thumb_opcode = 0b0110; break;
case RSC: break;
case TST: thumb_opcode = 0b1000; rn = so.GetRegister(); break;
case TEQ: break;
case CMP:
if (use_immediate) {
// T2 encoding.
dp_opcode = 0;
opcode_shift = 11;
thumb_opcode = 0b101;
rd_shift = 8;
rn_shift = 8;
} else {
thumb_opcode = 0b1010;
rd = rn;
rn = so.GetRegister();
}
break;
case CMN: {
thumb_opcode = 0b1011;
rd = rn;
rn = so.GetRegister();
break;
}
case ORR: thumb_opcode = 0b1100; break;
case MOV:
dp_opcode = 0;
if (use_immediate) {
// T2 encoding.
opcode_shift = 11;
thumb_opcode = 0b100;
rd_shift = 8;
rn_shift = 8;
} else {
rn = so.GetRegister();
if (IsHighRegister(rn) || IsHighRegister(rd)) {
// Special mov for high registers.
dp_opcode = 0b01;
opcode_shift = 7;
// Put the top bit of rd into the bottom bit of the opcode.
thumb_opcode = 0b0001100 | static_cast<uint32_t>(rd) >> 3;
rd = static_cast<Register>(static_cast<uint32_t>(rd) & 0b111);
} else {
thumb_opcode = 0;
}
}
break;
case BIC: thumb_opcode = 0b1110; break;
case MVN: thumb_opcode = 0b1111; rn = so.GetRegister(); break;
default:
break;
}
}
if (thumb_opcode == 0b11111111) {
LOG(FATAL) << "Invalid thumb1 opcode " << opcode;
}
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,
int 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;
uint8_t immediate = 0;
uint8_t thumb_opcode;;
if (so.IsImmediate()) {
use_immediate = true;
immediate = so.GetImmediate();
}
switch (opcode) {
case ADD:
if (so.IsRegister()) {
Register rm = so.GetRegister();
if (rn == rd) {
// Can use T2 encoding (allows 4 bit registers)
dp_opcode = 0b01;
opcode_shift = 10;
thumb_opcode = 0b0001;
// Make Rn also contain the top bit of rd.
rn = static_cast<Register>(static_cast<uint32_t>(rm) |
(static_cast<uint32_t>(rd) & 0b1000) << 1);
rd = static_cast<Register>(static_cast<uint32_t>(rd) & 0b111);
} else {
// T1.
opcode_shift = 9;
thumb_opcode = 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 = 0b10;
thumb_opcode = 0b11;
opcode_shift = 12;
CHECK_LT(immediate, (1 << 9));
CHECK_EQ((immediate & 0b11), 0);
// 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 = 0b10;
thumb_opcode = 0b101;
opcode_shift = 11;
CHECK_LT(immediate, (1 << 10));
CHECK_EQ((immediate & 0b11), 0);
// Remove rn from instruction.
rn = R0;
rn_shift = 0;
rd_shift = 8;
immediate >>= 2;
} else if (rn != rd) {
// Must use T1.
opcode_shift = 9;
thumb_opcode = 0b01110;
immediate_shift = 6;
} else {
// T2 encoding.
opcode_shift = 11;
thumb_opcode = 0b110;
rd_shift = 8;
rn_shift = 8;
}
}
break;
case SUB:
if (so.IsRegister()) {
// T1.
opcode_shift = 9;
thumb_opcode = 0b01101;
immediate = static_cast<uint32_t>(so.GetRegister());
use_immediate = true;
immediate_shift = 6;
} else {
if (rd == SP && rn == SP) {
// SUB sp, sp, #imm
dp_opcode = 0b10;
thumb_opcode = 0b1100001;
opcode_shift = 7;
CHECK_LT(immediate, (1 << 9));
CHECK_EQ((immediate & 0b11), 0);
// 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.
opcode_shift = 9;
thumb_opcode = 0b01111;
immediate_shift = 6;
} else {
// T2 encoding.
opcode_shift = 11;
thumb_opcode = 0b111;
rd_shift = 8;
rn_shift = 8;
}
}
break;
default:
LOG(FATAL) << "This opcode is not an ADD or SUB: " << opcode;
return;
}
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,
int 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, bool setcc) {
CHECK_LT(amount, (1 << 5));
if (IsHighRegister(rd) || IsHighRegister(rm) || shift == ROR || shift == RRX) {
uint16_t opcode = 0;
switch (shift) {
case LSL: opcode = 0b00; break;
case LSR: opcode = 0b01; break;
case ASR: opcode = 0b10; break;
case ROR: opcode = 0b11; break;
case RRX: opcode = 0b11; amount = 0; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
}
// 32 bit.
int32_t encoding = B31 | B30 | B29 | B27 | B25 | B22 |
0xf << 16 | (setcc ? B20 : 0);
uint32_t imm3 = amount >> 2;
uint32_t imm2 = amount & 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 = 0b00; break;
case LSR: opcode = 0b01; break;
case ASR: opcode = 0b10; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
}
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, bool setcc) {
CHECK_NE(shift, RRX);
bool must_be_32bit = false;
if (IsHighRegister(rd) || IsHighRegister(rm) || IsHighRegister(rn) || rd != rn) {
must_be_32bit = true;
}
if (must_be_32bit) {
uint16_t opcode = 0;
switch (shift) {
case LSL: opcode = 0b00; break;
case LSR: opcode = 0b01; break;
case ASR: opcode = 0b10; break;
case ROR: opcode = 0b11; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
}
// 32 bit.
int32_t encoding = B31 | B30 | B29 | B28 | B27 | B25 |
0xf << 12 | (setcc ? 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 = 0b0010; break;
case LSR: opcode = 0b0011; break;
case ASR: opcode = 0b0100; break;
default:
LOG(FATAL) << "Unsupported thumb2 shift opcode";
}
int16_t encoding = B14 | opcode << 6 | static_cast<int16_t>(rm) << 3 |
static_cast<int16_t>(rd);
Emit16(encoding);
}
}
void Thumb2Assembler::Branch::Emit(AssemblerBuffer* buffer) const {
bool link = type_ == kUnconditionalLinkX || type_ == kUnconditionalLink;
bool x = type_ == kUnconditionalX || type_ == kUnconditionalLinkX;
int32_t offset = target_ - location_;
if (size_ == k32Bit) {
int32_t encoding = B31 | B30 | B29 | B28 | B15;
if (link) {
// BL or BLX immediate.
encoding |= B14;
if (!x) {
encoding |= B12;
} else {
// Bottom bit of offset must be 0.
CHECK_EQ((offset & 1), 0);
}
} else {
if (x) {
LOG(FATAL) << "Invalid use of BX";
} else {
if (cond_ == AL) {
// Can use the T4 encoding allowing a 24 bit offset.
if (!x) {
encoding |= B12;
}
} else {
// Must be T3 encoding with a 20 bit offset.
encoding |= cond_ << 22;
}
}
}
encoding = Thumb2Assembler::EncodeBranchOffset(offset, encoding);
buffer->Store<int16_t>(location_, static_cast<int16_t>(encoding >> 16));
buffer->Store<int16_t>(location_+2, static_cast<int16_t>(encoding & 0xffff));
} else {
if (IsCompareAndBranch()) {
offset -= 4;
uint16_t i = (offset >> 6) & 1;
uint16_t imm5 = (offset >> 1) & 0b11111;
int16_t encoding = B15 | B13 | B12 |
(type_ == kCompareAndBranchNonZero ? B11 : 0) |
static_cast<uint32_t>(rn_) |
B8 |
i << 9 |
imm5 << 3;
buffer->Store<int16_t>(location_, encoding);
} else {
offset -= 4; // Account for PC offset.
int16_t encoding;
// 16 bit.
if (cond_ == AL) {
encoding = B15 | B14 | B13 |
((offset >> 1) & 0x7ff);
} else {
encoding = B15 | B14 | B12 |
cond_ << 8 | ((offset >> 1) & 0xff);
}
buffer->Store<int16_t>(location_, encoding);
}
}
}
uint16_t Thumb2Assembler::EmitCompareAndBranch(Register rn, uint16_t prev, bool n) {
uint32_t location = buffer_.Size();
// This is always unresolved as it must be a forward branch.
Emit16(prev); // Previous link.
return AddBranch(n ? Branch::kCompareAndBranchNonZero : Branch::kCompareAndBranchZero,
location, rn);
}
// 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 = 0b0111;
} else if (half) {
opA = 0b1000;
} else {
if (rn == SP) {
opA = 0b1001;
sp_relative = true;
} else {
opA = 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_EQ((offset & 0b11), 0);
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_EQ((offset & 0b1), 0);
offset >>= 1;
} else {
// 7 bit offset, shifted by 2.
CHECK_LT(offset, (1 << 7));
CHECK_EQ((offset & 0b11), 0);
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 am,
bool load,
Register base,
RegList regs) {
CHECK_NE(base, kNoRegister);
CheckCondition(cond);
bool must_be_32bit = force_32bit_;
if ((regs & 0xff00) != 0) {
must_be_32bit = true;
}
uint32_t w_bit = am == IA_W || am == DB_W || am == DA_W || am == IB_W;
// 16 bit always uses writeback.
if (!w_bit) {
must_be_32bit = true;
}
if (must_be_32bit) {
uint32_t op = 0;
switch (am) {
case IA:
case IA_W:
op = 0b01;
break;
case DB:
case DB_W:
op = 0b10;
break;
case DA:
case IB:
case DA_W:
case IB_W:
LOG(FATAL) << "LDM/STM mode not supported on thumb: " << am;
}
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) {
uint32_t pc = buffer_.Size();
Branch::Type branch_type;
if (cond == AL) {
if (link) {
if (x) {
branch_type = Branch::kUnconditionalLinkX; // BLX.
} else {
branch_type = Branch::kUnconditionalLink; // BX.
}
} else {
branch_type = Branch::kUnconditional; // B.
}
} else {
branch_type = Branch::kConditional; // B<cond>.
}
if (label->IsBound()) {
Branch::Size size = AddBranch(branch_type, pc, label->Position(), cond); // Resolved branch.
// The branch is to a bound label which means that it's a backwards branch. We know the
// current size of it so we can emit the appropriate space. Note that if it's a 16 bit
// branch the size may change if it so happens that other branches change size that change
// the distance to the target and that distance puts this branch over the limit for 16 bits.
if (size == Branch::k16Bit) {
DCHECK(!force_32bit_branches_);
Emit16(0); // Space for a 16 bit branch.
} else {
Emit32(0); // Space for a 32 bit branch.
}
} else {
// Branch is to an unbound label. Emit space for it.
uint16_t branch_id = AddBranch(branch_type, pc, cond); // Unresolved branch.
if (force_32bit_branches_ || force_32bit_) {
Emit16(static_cast<uint16_t>(label->position_)); // Emit current label link.
Emit16(0); // another 16 bits.
} else {
Emit16(static_cast<uint16_t>(label->position_)); // Emit current label link.
}
label->LinkTo(branch_id); // Link to the branch ID.
}
}
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 = B31 | B30 | B29 | B28 | B27 |
B25 | B23 | B21 | B20 |
static_cast<uint32_t>(rm) << 16 |
0xf << 12 |
static_cast<uint32_t>(rd) << 8 |
B7 |
static_cast<uint32_t>(rm);
Emit32(encoding);
}
void Thumb2Assembler::movw(Register rd, uint16_t imm16, Condition cond) {
CheckCondition(cond);
bool must_be_32bit = force_32bit_;
if (IsHighRegister(rd)|| imm16 >= 256u) {
must_be_32bit = true;
}
if (must_be_32bit) {
// Use encoding T3.
uint32_t imm4 = (imm16 >> 12) & 0b1111;
uint32_t i = (imm16 >> 11) & 0b1;
uint32_t imm3 = (imm16 >> 8) & 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);
} else {
int16_t encoding = B13 | static_cast<uint16_t>(rd) << 8 |
imm16;
Emit16(encoding);
}
}
void Thumb2Assembler::movt(Register rd, uint16_t imm16, Condition cond) {
CheckCondition(cond);
// Always 32 bits.
uint32_t imm4 = (imm16 >> 12) & 0b1111;
uint32_t i = (imm16 >> 11) & 0b1;
uint32_t imm3 = (imm16 >> 8) & 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::ldrex(Register rt, Register rn, uint16_t imm, Condition cond) {
CHECK_NE(rn, kNoRegister);
CHECK_NE(rt, kNoRegister);
CheckCondition(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::strex(Register rd,
Register rt,
Register rn,
Condition cond) {
strex(rd, rt, rn, 0, cond);
}
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);
int16_t encoding = B15 | B13 | B12 |
B11 | B10 | B9 | B8;
Emit16(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 & 0b1111;
} else {
// Encoded as Vd:D.
D = reg & 1;
Vd = (reg >> 1) & 0b1111;
}
int32_t encoding = B27 | B26 | B21 | B19 | B18 | B16 |
B11 | B9 |
(dbl ? B8 : 0) |
(push ? B24 : (B23 | B20)) |
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.
CheckCondition(cond);
UNIMPLEMENTED(FATAL) << "Unimplemented thumb instruction";
}
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 |= 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";
} 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";
} 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);
}
}
// A branch has changed size. Make a hole for it.
void Thumb2Assembler::MakeHoleForBranch(uint32_t location, uint32_t delta) {
// Move the contents of the buffer using: Move(newposition, oldposition)
AssemblerBuffer::EnsureCapacity ensured(&buffer_);
buffer_.Move(location + delta, location);
}
void Thumb2Assembler::Bind(Label* label) {
CHECK(!label->IsBound());
uint32_t bound_pc = buffer_.Size();
std::vector<Branch*> changed_branches;
while (label->IsLinked()) {
uint16_t position = label->Position(); // Branch id for linked branch.
Branch* branch = GetBranch(position); // Get the branch at this id.
bool changed = branch->Resolve(bound_pc); // Branch can be resolved now.
uint32_t branch_location = branch->GetLocation();
uint16_t next = buffer_.Load<uint16_t>(branch_location); // Get next in chain.
if (changed) {
DCHECK(!force_32bit_branches_);
MakeHoleForBranch(branch->GetLocation(), 2);
if (branch->IsCompareAndBranch()) {
// A cbz/cbnz instruction has changed size. There is no valid encoding for
// a 32 bit cbz/cbnz so we need to change this to an instruction pair:
// cmp rn, #0
// b<eq|ne> target
bool n = branch->GetType() == Branch::kCompareAndBranchNonZero;
Condition cond = n ? NE : EQ;
branch->Move(2); // Move the branch forward by 2 bytes.
branch->ResetTypeAndCondition(Branch::kConditional, cond);
branch->ResetSize(Branch::k16Bit);
// Now add a compare instruction in the place the branch was.
int16_t cmp = B13 | B11 | static_cast<int16_t>(branch->GetRegister()) << 8;
buffer_.Store<int16_t>(branch_location, cmp);
// Since have moved made a hole in the code we need to reload the
// current pc.
bound_pc = buffer_.Size();
// Now resolve the newly added branch.
changed = branch->Resolve(bound_pc);
if (changed) {
MakeHoleForBranch(branch->GetLocation(), 2);
changed_branches.push_back(branch);
}
} else {
changed_branches.push_back(branch);
}
}
label->position_ = next; // Move to next.
}
label->BindTo(bound_pc);
// Now relocate any changed branches. Do this until there are no more changes.
std::vector<Branch*> branches_to_process = changed_branches;
while (branches_to_process.size() != 0) {
changed_branches.clear();
for (auto& changed_branch : branches_to_process) {
for (auto& branch : branches_) {
bool changed = branch->Relocate(changed_branch->GetLocation(), 2);
if (changed) {
changed_branches.push_back(branch);
}
}
branches_to_process = changed_branches;
}
}
}
void Thumb2Assembler::EmitBranches() {
for (auto& branch : branches_) {
branch->Emit(&buffer_);
}
}
void Thumb2Assembler::Lsl(Register rd, Register rm, uint32_t shift_imm,
bool setcc, Condition cond) {
CHECK_NE(shift_imm, 0u); // Do not use Lsl if no shift is wanted.
CheckCondition(cond);
EmitShift(rd, rm, LSL, shift_imm, setcc);
}
void Thumb2Assembler::Lsr(Register rd, Register rm, uint32_t shift_imm,
bool setcc, Condition cond) {
CHECK_NE(shift_imm, 0u); // Do not use Lsr if no shift is wanted.
if (shift_imm == 32) shift_imm = 0; // Comply to UAL syntax.
CheckCondition(cond);
EmitShift(rd, rm, LSR, shift_imm, setcc);
}
void Thumb2Assembler::Asr(Register rd, Register rm, uint32_t shift_imm,
bool setcc, Condition cond) {
CHECK_NE(shift_imm, 0u); // Do not use Asr if no shift is wanted.
if (shift_imm == 32) shift_imm = 0; // Comply to UAL syntax.
CheckCondition(cond);
EmitShift(rd, rm, ASR, shift_imm, setcc);
}
void Thumb2Assembler::Ror(Register rd, Register rm, uint32_t shift_imm,
bool setcc, Condition cond) {
CHECK_NE(shift_imm, 0u); // Use Rrx instruction.
CheckCondition(cond);
EmitShift(rd, rm, ROR, shift_imm, setcc);
}
void Thumb2Assembler::Rrx(Register rd, Register rm, bool setcc, Condition cond) {
CheckCondition(cond);
EmitShift(rd, rm, RRX, rm, setcc);
}
void Thumb2Assembler::Lsl(Register rd, Register rm, Register rn,
bool setcc, Condition cond) {
CheckCondition(cond);
EmitShift(rd, rm, LSL, rn, setcc);
}
void Thumb2Assembler::Lsr(Register rd, Register rm, Register rn,
bool setcc, Condition cond) {
CheckCondition(cond);
EmitShift(rd, rm, LSR, rn, setcc);
}
void Thumb2Assembler::Asr(Register rd, Register rm, Register rn,
bool setcc, Condition cond) {
CheckCondition(cond);
EmitShift(rd, rm, ASR, rn, setcc);
}
void Thumb2Assembler::Ror(Register rd, Register rm, Register rn,
bool setcc, Condition cond) {
CheckCondition(cond);
EmitShift(rd, rm, ROR, rn, setcc);
}
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;
}
void Thumb2Assembler::AddConstant(Register rd, int32_t value, Condition cond) {
AddConstant(rd, rd, value, cond);
}
void Thumb2Assembler::AddConstant(Register rd, Register rn, int32_t value,
Condition cond) {
if (value == 0) {
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 (ShifterOperand::CanHoldThumb(rd, rn, ADD, value, &shifter_op)) {
add(rd, rn, shifter_op, cond);
} else if (ShifterOperand::CanHoldThumb(rd, rn, SUB, -value, &shifter_op)) {
sub(rd, rn, shifter_op, cond);
} else {
CHECK(rn != IP);
if (ShifterOperand::CanHoldThumb(rd, rn, MVN, ~value, &shifter_op)) {
mvn(IP, shifter_op, cond);
add(rd, rn, ShifterOperand(IP), cond);
} else if (ShifterOperand::CanHoldThumb(rd, rn, MVN, ~(-value), &shifter_op)) {
mvn(IP, shifter_op, cond);
sub(rd, 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);
}
add(rd, rn, ShifterOperand(IP), cond);
}
}
}
void Thumb2Assembler::AddConstantSetFlags(Register rd, Register rn, int32_t value,
Condition cond) {
ShifterOperand shifter_op;
if (ShifterOperand::CanHoldThumb(rd, rn, ADD, value, &shifter_op)) {
adds(rd, rn, shifter_op, cond);
} else if (ShifterOperand::CanHoldThumb(rd, rn, ADD, -value, &shifter_op)) {
subs(rd, rn, shifter_op, cond);
} else {
CHECK(rn != IP);
if (ShifterOperand::CanHoldThumb(rd, rn, MVN, ~value, &shifter_op)) {
mvn(IP, shifter_op, cond);
adds(rd, rn, ShifterOperand(IP), cond);
} else if (ShifterOperand::CanHoldThumb(rd, rn, MVN, ~(-value), &shifter_op)) {
mvn(IP, shifter_op, cond);
subs(rd, 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);
}
adds(rd, rn, ShifterOperand(IP), cond);
}
}
}
void Thumb2Assembler::LoadImmediate(Register rd, int32_t value, Condition cond) {
ShifterOperand shifter_op;
if (ShifterOperand::CanHoldThumb(rd, R0, MOV, value, &shifter_op)) {
mov(rd, shifter_op, cond);
} else if (ShifterOperand::CanHoldThumb(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);
}
}
}
// 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(base != IP);
LoadImmediate(IP, offset, cond);
add(IP, IP, ShifterOperand(base), cond);
base = IP;
offset = 0;
}