/*
* Copyright (C) 2008 Apple Inc.
* Copyright (C) 2009 University of Szeged
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef MacroAssemblerARM_h
#define MacroAssemblerARM_h
#include <wtf/Platform.h>
#if ENABLE(ASSEMBLER) && PLATFORM(ARM)
#include "ARMAssembler.h"
#include "AbstractMacroAssembler.h"
namespace JSC {
class MacroAssemblerARM : public AbstractMacroAssembler<ARMAssembler> {
public:
enum Condition {
Equal = ARMAssembler::EQ,
NotEqual = ARMAssembler::NE,
Above = ARMAssembler::HI,
AboveOrEqual = ARMAssembler::CS,
Below = ARMAssembler::CC,
BelowOrEqual = ARMAssembler::LS,
GreaterThan = ARMAssembler::GT,
GreaterThanOrEqual = ARMAssembler::GE,
LessThan = ARMAssembler::LT,
LessThanOrEqual = ARMAssembler::LE,
Overflow = ARMAssembler::VS,
Signed = ARMAssembler::MI,
Zero = ARMAssembler::EQ,
NonZero = ARMAssembler::NE
};
enum DoubleCondition {
DoubleEqual = ARMAssembler::EQ,
DoubleGreaterThan = ARMAssembler::GT,
DoubleGreaterThanOrEqual = ARMAssembler::GE,
DoubleLessThan = ARMAssembler::LT,
DoubleLessThanOrEqual = ARMAssembler::LE,
};
static const RegisterID stackPointerRegister = ARM::sp;
static const Scale ScalePtr = TimesFour;
void add32(RegisterID src, RegisterID dest)
{
m_assembler.adds_r(dest, dest, src);
}
void add32(Imm32 imm, Address address)
{
load32(address, ARM::S1);
add32(imm, ARM::S1);
store32(ARM::S1, address);
}
void add32(Imm32 imm, RegisterID dest)
{
m_assembler.adds_r(dest, dest, m_assembler.getImm(imm.m_value, ARM::S0));
}
void add32(Address src, RegisterID dest)
{
load32(src, ARM::S1);
add32(ARM::S1, dest);
}
void and32(RegisterID src, RegisterID dest)
{
m_assembler.ands_r(dest, dest, src);
}
void and32(Imm32 imm, RegisterID dest)
{
ARMWord w = m_assembler.getImm(imm.m_value, ARM::S0, true);
if (w & ARMAssembler::OP2_INV_IMM)
m_assembler.bics_r(dest, dest, w & ~ARMAssembler::OP2_INV_IMM);
else
m_assembler.ands_r(dest, dest, w);
}
void lshift32(Imm32 imm, RegisterID dest)
{
m_assembler.movs_r(dest, m_assembler.lsl(dest, imm.m_value & 0x1f));
}
void lshift32(RegisterID shift_amount, RegisterID dest)
{
m_assembler.movs_r(dest, m_assembler.lsl_r(dest, shift_amount));
}
void mul32(RegisterID src, RegisterID dest)
{
if (src == dest) {
move(src, ARM::S0);
src = ARM::S0;
}
m_assembler.muls_r(dest, dest, src);
}
void mul32(Imm32 imm, RegisterID src, RegisterID dest)
{
move(imm, ARM::S0);
m_assembler.muls_r(dest, src, ARM::S0);
}
void not32(RegisterID dest)
{
m_assembler.mvns_r(dest, dest);
}
void or32(RegisterID src, RegisterID dest)
{
m_assembler.orrs_r(dest, dest, src);
}
void or32(Imm32 imm, RegisterID dest)
{
m_assembler.orrs_r(dest, dest, m_assembler.getImm(imm.m_value, ARM::S0));
}
void rshift32(RegisterID shift_amount, RegisterID dest)
{
m_assembler.movs_r(dest, m_assembler.asr_r(dest, shift_amount));
}
void rshift32(Imm32 imm, RegisterID dest)
{
m_assembler.movs_r(dest, m_assembler.asr(dest, imm.m_value & 0x1f));
}
void sub32(RegisterID src, RegisterID dest)
{
m_assembler.subs_r(dest, dest, src);
}
void sub32(Imm32 imm, RegisterID dest)
{
m_assembler.subs_r(dest, dest, m_assembler.getImm(imm.m_value, ARM::S0));
}
void sub32(Imm32 imm, Address address)
{
load32(address, ARM::S1);
sub32(imm, ARM::S1);
store32(ARM::S1, address);
}
void sub32(Address src, RegisterID dest)
{
load32(src, ARM::S1);
sub32(ARM::S1, dest);
}
void xor32(RegisterID src, RegisterID dest)
{
m_assembler.eors_r(dest, dest, src);
}
void xor32(Imm32 imm, RegisterID dest)
{
m_assembler.eors_r(dest, dest, m_assembler.getImm(imm.m_value, ARM::S0));
}
void load32(ImplicitAddress address, RegisterID dest)
{
m_assembler.dataTransfer32(true, dest, address.base, address.offset);
}
void load32(BaseIndex address, RegisterID dest)
{
m_assembler.baseIndexTransfer32(true, dest, address.base, address.index, static_cast<int>(address.scale), address.offset);
}
DataLabel32 load32WithAddressOffsetPatch(Address address, RegisterID dest)
{
DataLabel32 dataLabel(this);
m_assembler.ldr_un_imm(ARM::S0, 0);
m_assembler.dtr_ur(true, dest, address.base, ARM::S0);
return dataLabel;
}
Label loadPtrWithPatchToLEA(Address address, RegisterID dest)
{
Label label(this);
load32(address, dest);
return label;
}
void load16(BaseIndex address, RegisterID dest)
{
m_assembler.add_r(ARM::S0, address.base, m_assembler.lsl(address.index, address.scale));
if (address.offset>=0)
m_assembler.ldrh_u(dest, ARM::S0, ARMAssembler::getOp2Byte(address.offset));
else
m_assembler.ldrh_d(dest, ARM::S0, ARMAssembler::getOp2Byte(-address.offset));
}
DataLabel32 store32WithAddressOffsetPatch(RegisterID src, Address address)
{
DataLabel32 dataLabel(this);
m_assembler.ldr_un_imm(ARM::S0, 0);
m_assembler.dtr_ur(false, src, address.base, ARM::S0);
return dataLabel;
}
void store32(RegisterID src, ImplicitAddress address)
{
m_assembler.dataTransfer32(false, src, address.base, address.offset);
}
void store32(RegisterID src, BaseIndex address)
{
m_assembler.baseIndexTransfer32(false, src, address.base, address.index, static_cast<int>(address.scale), address.offset);
}
void store32(Imm32 imm, ImplicitAddress address)
{
if (imm.m_isPointer)
m_assembler.ldr_un_imm(ARM::S1, imm.m_value);
else
move(imm, ARM::S1);
store32(ARM::S1, address);
}
void store32(RegisterID src, void* address)
{
m_assembler.ldr_un_imm(ARM::S0, reinterpret_cast<ARMWord>(address));
m_assembler.dtr_u(false, src, ARM::S0, 0);
}
void store32(Imm32 imm, void* address)
{
m_assembler.ldr_un_imm(ARM::S0, reinterpret_cast<ARMWord>(address));
if (imm.m_isPointer)
m_assembler.ldr_un_imm(ARM::S1, imm.m_value);
else
m_assembler.moveImm(imm.m_value, ARM::S1);
m_assembler.dtr_u(false, ARM::S1, ARM::S0, 0);
}
void pop(RegisterID dest)
{
m_assembler.pop_r(dest);
}
void push(RegisterID src)
{
m_assembler.push_r(src);
}
void push(Address address)
{
load32(address, ARM::S1);
push(ARM::S1);
}
void push(Imm32 imm)
{
move(imm, ARM::S0);
push(ARM::S0);
}
void move(Imm32 imm, RegisterID dest)
{
if (imm.m_isPointer)
m_assembler.ldr_un_imm(dest, imm.m_value);
else
m_assembler.moveImm(imm.m_value, dest);
}
void move(RegisterID src, RegisterID dest)
{
m_assembler.mov_r(dest, src);
}
void move(ImmPtr imm, RegisterID dest)
{
move(Imm32(imm), dest);
}
void swap(RegisterID reg1, RegisterID reg2)
{
m_assembler.mov_r(ARM::S0, reg1);
m_assembler.mov_r(reg1, reg2);
m_assembler.mov_r(reg2, ARM::S0);
}
void signExtend32ToPtr(RegisterID src, RegisterID dest)
{
if (src != dest)
move(src, dest);
}
void zeroExtend32ToPtr(RegisterID src, RegisterID dest)
{
if (src != dest)
move(src, dest);
}
Jump branch32(Condition cond, RegisterID left, RegisterID right)
{
m_assembler.cmp_r(left, right);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branch32(Condition cond, RegisterID left, Imm32 right)
{
if (right.m_isPointer) {
m_assembler.ldr_un_imm(ARM::S0, right.m_value);
m_assembler.cmp_r(left, ARM::S0);
} else
m_assembler.cmp_r(left, m_assembler.getImm(right.m_value, ARM::S0));
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branch32(Condition cond, RegisterID left, Address right)
{
load32(right, ARM::S1);
return branch32(cond, left, ARM::S1);
}
Jump branch32(Condition cond, Address left, RegisterID right)
{
load32(left, ARM::S1);
return branch32(cond, ARM::S1, right);
}
Jump branch32(Condition cond, Address left, Imm32 right)
{
load32(left, ARM::S1);
return branch32(cond, ARM::S1, right);
}
Jump branch32(Condition cond, BaseIndex left, Imm32 right)
{
load32(left, ARM::S1);
return branch32(cond, ARM::S1, right);
}
Jump branch16(Condition cond, BaseIndex left, RegisterID right)
{
UNUSED_PARAM(cond);
UNUSED_PARAM(left);
UNUSED_PARAM(right);
ASSERT_NOT_REACHED();
return jump();
}
Jump branch16(Condition cond, BaseIndex left, Imm32 right)
{
load16(left, ARM::S0);
move(right, ARM::S1);
m_assembler.cmp_r(ARM::S0, ARM::S1);
return m_assembler.jmp(ARMCondition(cond));
}
Jump branchTest32(Condition cond, RegisterID reg, RegisterID mask)
{
ASSERT((cond == Zero) || (cond == NonZero));
m_assembler.tst_r(reg, mask);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branchTest32(Condition cond, RegisterID reg, Imm32 mask = Imm32(-1))
{
ASSERT((cond == Zero) || (cond == NonZero));
ARMWord w = m_assembler.getImm(mask.m_value, ARM::S0, true);
if (w & ARMAssembler::OP2_INV_IMM)
m_assembler.bics_r(ARM::S0, reg, w & ~ARMAssembler::OP2_INV_IMM);
else
m_assembler.tst_r(reg, w);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branchTest32(Condition cond, Address address, Imm32 mask = Imm32(-1))
{
load32(address, ARM::S1);
return branchTest32(cond, ARM::S1, mask);
}
Jump branchTest32(Condition cond, BaseIndex address, Imm32 mask = Imm32(-1))
{
load32(address, ARM::S1);
return branchTest32(cond, ARM::S1, mask);
}
Jump jump()
{
return Jump(m_assembler.jmp());
}
void jump(RegisterID target)
{
move(target, ARM::pc);
}
void jump(Address address)
{
load32(address, ARM::pc);
}
Jump branchAdd32(Condition cond, RegisterID src, RegisterID dest)
{
ASSERT((cond == Overflow) || (cond == Signed) || (cond == Zero) || (cond == NonZero));
add32(src, dest);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branchAdd32(Condition cond, Imm32 imm, RegisterID dest)
{
ASSERT((cond == Overflow) || (cond == Signed) || (cond == Zero) || (cond == NonZero));
add32(imm, dest);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
void mull32(RegisterID src1, RegisterID src2, RegisterID dest)
{
if (src1 == dest) {
move(src1, ARM::S0);
src1 = ARM::S0;
}
m_assembler.mull_r(ARM::S1, dest, src2, src1);
m_assembler.cmp_r(ARM::S1, m_assembler.asr(dest, 31));
}
Jump branchMul32(Condition cond, RegisterID src, RegisterID dest)
{
ASSERT((cond == Overflow) || (cond == Signed) || (cond == Zero) || (cond == NonZero));
if (cond == Overflow) {
mull32(src, dest, dest);
cond = NonZero;
}
else
mul32(src, dest);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branchMul32(Condition cond, Imm32 imm, RegisterID src, RegisterID dest)
{
ASSERT((cond == Overflow) || (cond == Signed) || (cond == Zero) || (cond == NonZero));
if (cond == Overflow) {
move(imm, ARM::S0);
mull32(ARM::S0, src, dest);
cond = NonZero;
}
else
mul32(imm, src, dest);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branchSub32(Condition cond, RegisterID src, RegisterID dest)
{
ASSERT((cond == Overflow) || (cond == Signed) || (cond == Zero) || (cond == NonZero));
sub32(src, dest);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
Jump branchSub32(Condition cond, Imm32 imm, RegisterID dest)
{
ASSERT((cond == Overflow) || (cond == Signed) || (cond == Zero) || (cond == NonZero));
sub32(imm, dest);
return Jump(m_assembler.jmp(ARMCondition(cond)));
}
void breakpoint()
{
m_assembler.bkpt(0);
}
Call nearCall()
{
prepareCall();
return Call(m_assembler.jmp(), Call::LinkableNear);
}
Call call(RegisterID target)
{
prepareCall();
move(ARM::pc, target);
JmpSrc jmpSrc;
return Call(jmpSrc, Call::None);
}
void call(Address address)
{
call32(address.base, address.offset);
}
void ret()
{
pop(ARM::pc);
}
void set32(Condition cond, RegisterID left, RegisterID right, RegisterID dest)
{
m_assembler.cmp_r(left, right);
m_assembler.mov_r(dest, ARMAssembler::getOp2(0));
m_assembler.mov_r(dest, ARMAssembler::getOp2(1), ARMCondition(cond));
}
void set32(Condition cond, RegisterID left, Imm32 right, RegisterID dest)
{
m_assembler.cmp_r(left, m_assembler.getImm(right.m_value, ARM::S0));
m_assembler.mov_r(dest, ARMAssembler::getOp2(0));
m_assembler.mov_r(dest, ARMAssembler::getOp2(1), ARMCondition(cond));
}
void setTest32(Condition cond, Address address, Imm32 mask, RegisterID dest)
{
load32(address, ARM::S1);
if (mask.m_value == -1)
m_assembler.cmp_r(0, ARM::S1);
else
m_assembler.tst_r(ARM::S1, m_assembler.getImm(mask.m_value, ARM::S0));
m_assembler.mov_r(dest, ARMAssembler::getOp2(0));
m_assembler.mov_r(dest, ARMAssembler::getOp2(1), ARMCondition(cond));
}
void add32(Imm32 imm, RegisterID src, RegisterID dest)
{
m_assembler.add_r(dest, src, m_assembler.getImm(imm.m_value, ARM::S0));
}
void add32(Imm32 imm, AbsoluteAddress address)
{
m_assembler.ldr_un_imm(ARM::S1, reinterpret_cast<ARMWord>(address.m_ptr));
m_assembler.dtr_u(true, ARM::S1, ARM::S1, 0);
add32(imm, ARM::S1);
m_assembler.ldr_un_imm(ARM::S0, reinterpret_cast<ARMWord>(address.m_ptr));
m_assembler.dtr_u(false, ARM::S1, ARM::S0, 0);
}
void sub32(Imm32 imm, AbsoluteAddress address)
{
m_assembler.ldr_un_imm(ARM::S1, reinterpret_cast<ARMWord>(address.m_ptr));
m_assembler.dtr_u(true, ARM::S1, ARM::S1, 0);
sub32(imm, ARM::S1);
m_assembler.ldr_un_imm(ARM::S0, reinterpret_cast<ARMWord>(address.m_ptr));
m_assembler.dtr_u(false, ARM::S1, ARM::S0, 0);
}
void load32(void* address, RegisterID dest)
{
m_assembler.ldr_un_imm(ARM::S0, reinterpret_cast<ARMWord>(address));
m_assembler.dtr_u(true, dest, ARM::S0, 0);
}
Jump branch32(Condition cond, AbsoluteAddress left, RegisterID right)
{
load32(left.m_ptr, ARM::S1);
return branch32(cond, ARM::S1, right);
}
Jump branch32(Condition cond, AbsoluteAddress left, Imm32 right)
{
load32(left.m_ptr, ARM::S1);
return branch32(cond, ARM::S1, right);
}
Call call()
{
prepareCall();
return Call(m_assembler.jmp(), Call::Linkable);
}
Call tailRecursiveCall()
{
return Call::fromTailJump(jump());
}
Call makeTailRecursiveCall(Jump oldJump)
{
return Call::fromTailJump(oldJump);
}
DataLabelPtr moveWithPatch(ImmPtr initialValue, RegisterID dest)
{
DataLabelPtr dataLabel(this);
m_assembler.ldr_un_imm(dest, reinterpret_cast<ARMWord>(initialValue.m_value));
return dataLabel;
}
Jump branchPtrWithPatch(Condition cond, RegisterID left, DataLabelPtr& dataLabel, ImmPtr initialRightValue = ImmPtr(0))
{
dataLabel = moveWithPatch(initialRightValue, ARM::S1);
Jump jump = branch32(cond, left, ARM::S1);
jump.enableLatePatch();
return jump;
}
Jump branchPtrWithPatch(Condition cond, Address left, DataLabelPtr& dataLabel, ImmPtr initialRightValue = ImmPtr(0))
{
load32(left, ARM::S1);
dataLabel = moveWithPatch(initialRightValue, ARM::S0);
Jump jump = branch32(cond, ARM::S0, ARM::S1);
jump.enableLatePatch();
return jump;
}
DataLabelPtr storePtrWithPatch(ImmPtr initialValue, ImplicitAddress address)
{
DataLabelPtr dataLabel = moveWithPatch(initialValue, ARM::S1);
store32(ARM::S1, address);
return dataLabel;
}
DataLabelPtr storePtrWithPatch(ImplicitAddress address)
{
return storePtrWithPatch(ImmPtr(0), address);
}
// Floating point operators
bool supportsFloatingPoint() const
{
// FIXME: should be a dynamic test: VFP, FPA, or nothing
return false;
}
bool supportsFloatingPointTruncate() const
{
return false;
}
void loadDouble(ImplicitAddress address, FPRegisterID dest)
{
m_assembler.doubleTransfer(true, dest, address.base, address.offset);
}
void storeDouble(FPRegisterID src, ImplicitAddress address)
{
m_assembler.doubleTransfer(false, src, address.base, address.offset);
}
void addDouble(FPRegisterID src, FPRegisterID dest)
{
m_assembler.faddd_r(dest, dest, src);
}
void addDouble(Address src, FPRegisterID dest)
{
loadDouble(src, ARM::SD0);
addDouble(ARM::SD0, dest);
}
void subDouble(FPRegisterID src, FPRegisterID dest)
{
m_assembler.fsubd_r(dest, dest, src);
}
void subDouble(Address src, FPRegisterID dest)
{
loadDouble(src, ARM::SD0);
subDouble(ARM::SD0, dest);
}
void mulDouble(FPRegisterID src, FPRegisterID dest)
{
m_assembler.fmuld_r(dest, dest, src);
}
void mulDouble(Address src, FPRegisterID dest)
{
loadDouble(src, ARM::SD0);
mulDouble(ARM::SD0, dest);
}
void convertInt32ToDouble(RegisterID src, FPRegisterID dest)
{
m_assembler.fmsr_r(dest, src);
m_assembler.fsitod_r(dest, dest);
}
Jump branchDouble(DoubleCondition cond, FPRegisterID left, FPRegisterID right)
{
m_assembler.fcmpd_r(left, right);
m_assembler.fmstat();
return Jump(m_assembler.jmp(static_cast<ARMAssembler::Condition>(cond)));
}
// Truncates 'src' to an integer, and places the resulting 'dest'.
// If the result is not representable as a 32 bit value, branch.
// May also branch for some values that are representable in 32 bits
// (specifically, in this case, INT_MIN).
Jump branchTruncateDoubleToInt32(FPRegisterID src, RegisterID dest)
{
UNUSED_PARAM(src);
UNUSED_PARAM(dest);
ASSERT_NOT_REACHED();
return jump();
}
protected:
ARMAssembler::Condition ARMCondition(Condition cond)
{
return static_cast<ARMAssembler::Condition>(cond);
}
void prepareCall()
{
m_assembler.ensureSpace(3 * sizeof(ARMWord), sizeof(ARMWord));
// S0 might be used for parameter passing
m_assembler.add_r(ARM::S1, ARM::pc, ARMAssembler::OP2_IMM | 0x4);
m_assembler.push_r(ARM::S1);
}
void call32(RegisterID base, int32_t offset)
{
if (base == ARM::sp)
offset += 4;
if (offset >= 0) {
if (offset <= 0xfff) {
prepareCall();
m_assembler.dtr_u(true, ARM::pc, base, offset);
} else if (offset <= 0xfffff) {
m_assembler.add_r(ARM::S0, base, ARMAssembler::OP2_IMM | (offset >> 12) | (10 << 8));
prepareCall();
m_assembler.dtr_u(true, ARM::pc, ARM::S0, offset & 0xfff);
} else {
ARMWord reg = m_assembler.getImm(offset, ARM::S0);
prepareCall();
m_assembler.dtr_ur(true, ARM::pc, base, reg);
}
} else {
offset = -offset;
if (offset <= 0xfff) {
prepareCall();
m_assembler.dtr_d(true, ARM::pc, base, offset);
} else if (offset <= 0xfffff) {
m_assembler.sub_r(ARM::S0, base, ARMAssembler::OP2_IMM | (offset >> 12) | (10 << 8));
prepareCall();
m_assembler.dtr_d(true, ARM::pc, ARM::S0, offset & 0xfff);
} else {
ARMWord reg = m_assembler.getImm(offset, ARM::S0);
prepareCall();
m_assembler.dtr_dr(true, ARM::pc, base, reg);
}
}
}
private:
friend class LinkBuffer;
friend class RepatchBuffer;
static void linkCall(void* code, Call call, FunctionPtr function)
{
ARMAssembler::linkCall(code, call.m_jmp, function.value());
}
static void repatchCall(CodeLocationCall call, CodeLocationLabel destination)
{
ARMAssembler::relinkCall(call.dataLocation(), destination.executableAddress());
}
static void repatchCall(CodeLocationCall call, FunctionPtr destination)
{
ARMAssembler::relinkCall(call.dataLocation(), destination.executableAddress());
}
};
}
#endif
#endif // MacroAssemblerARM_h