1 //===-- ARM/ARMCodeEmitter.cpp - Convert ARM code to machine code ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the pass that transforms the ARM machine instructions into
11 // relocatable machine code.
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "arm-emitter"
17 #include "ARMAddressingModes.h"
18 #include "ARMInstrInfo.h"
19 #include "ARMRelocations.h"
20 #include "ARMSubtarget.h"
21 #include "ARMTargetMachine.h"
22 #include "llvm/Function.h"
23 #include "llvm/PassManager.h"
24 #include "llvm/CodeGen/MachineCodeEmitter.h"
25 #include "llvm/CodeGen/MachineFunctionPass.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/Passes.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/Support/Compiler.h"
30 #include "llvm/Support/Debug.h"
33 STATISTIC(NumEmitted, "Number of machine instructions emitted");
36 class VISIBILITY_HIDDEN ARMCodeEmitter : public MachineFunctionPass {
37 const ARMInstrInfo *II;
40 MachineCodeEmitter &MCE;
43 explicit ARMCodeEmitter(TargetMachine &tm, MachineCodeEmitter &mce)
44 : MachineFunctionPass(&ID), II(0), TD(0), TM(tm),
46 ARMCodeEmitter(TargetMachine &tm, MachineCodeEmitter &mce,
47 const ARMInstrInfo &ii, const TargetData &td)
48 : MachineFunctionPass(&ID), II(&ii), TD(&td), TM(tm),
51 bool runOnMachineFunction(MachineFunction &MF);
53 virtual const char *getPassName() const {
54 return "ARM Machine Code Emitter";
57 void emitInstruction(const MachineInstr &MI);
60 unsigned getAddrModeNoneInstrBinary(const MachineInstr &MI,
61 const TargetInstrDesc &TID,
64 unsigned getMachineSoRegOpValue(const MachineInstr &MI,
65 const TargetInstrDesc &TID,
68 unsigned getAddrMode1SBit(const MachineInstr &MI,
69 const TargetInstrDesc &TID) const;
71 unsigned getAddrMode1InstrBinary(const MachineInstr &MI,
72 const TargetInstrDesc &TID,
74 unsigned getAddrMode2InstrBinary(const MachineInstr &MI,
75 const TargetInstrDesc &TID,
77 unsigned getAddrMode3InstrBinary(const MachineInstr &MI,
78 const TargetInstrDesc &TID,
80 unsigned getAddrMode4InstrBinary(const MachineInstr &MI,
81 const TargetInstrDesc &TID,
84 /// getInstrBinary - Return binary encoding for the specified
85 /// machine instruction.
86 unsigned getInstrBinary(const MachineInstr &MI);
88 /// getBinaryCodeForInstr - This function, generated by the
89 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
90 /// machine instructions.
92 unsigned getBinaryCodeForInstr(const MachineInstr &MI);
94 /// getMachineOpValue - Return binary encoding of operand. If the machine
95 /// operand requires relocation, record the relocation and return zero.
96 unsigned getMachineOpValue(const MachineInstr &MI, unsigned OpIdx) {
97 return getMachineOpValue(MI, MI.getOperand(OpIdx));
99 unsigned getMachineOpValue(const MachineInstr &MI,
100 const MachineOperand &MO);
102 /// getBaseOpcodeFor - Return the opcode value.
104 unsigned getBaseOpcodeFor(const TargetInstrDesc &TID) const {
105 return (TID.TSFlags & ARMII::OpcodeMask) >> ARMII::OpcodeShift;
108 /// getShiftOp - Return the shift opcode (bit[6:5]) of the machine operand.
110 unsigned getShiftOp(const MachineOperand &MO) const ;
112 /// Routines that handle operands which add machine relocations which are
113 /// fixed up by the JIT fixup stage.
114 void emitGlobalAddressForCall(GlobalValue *GV, bool DoesntNeedStub);
115 void emitExternalSymbolAddress(const char *ES, unsigned Reloc);
116 void emitConstPoolAddress(unsigned CPI, unsigned Reloc,
117 int Disp = 0, unsigned PCAdj = 0 );
118 void emitJumpTableAddress(unsigned JTI, unsigned Reloc,
120 void emitGlobalConstant(const Constant *CV);
121 void emitMachineBasicBlock(MachineBasicBlock *BB);
123 char ARMCodeEmitter::ID = 0;
126 /// createARMCodeEmitterPass - Return a pass that emits the collected ARM code
127 /// to the specified MCE object.
128 FunctionPass *llvm::createARMCodeEmitterPass(ARMTargetMachine &TM,
129 MachineCodeEmitter &MCE) {
130 return new ARMCodeEmitter(TM, MCE);
133 bool ARMCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
134 assert((MF.getTarget().getRelocationModel() != Reloc::Default ||
135 MF.getTarget().getRelocationModel() != Reloc::Static) &&
136 "JIT relocation model must be set to static or default!");
137 II = ((ARMTargetMachine&)MF.getTarget()).getInstrInfo();
138 TD = ((ARMTargetMachine&)MF.getTarget()).getTargetData();
141 DOUT << "JITTing function '" << MF.getFunction()->getName() << "'\n";
142 MCE.startFunction(MF);
143 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
145 MCE.StartMachineBasicBlock(MBB);
146 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
150 } while (MCE.finishFunction(MF));
155 /// getShiftOp - Return the shift opcode (bit[6:5]) of the machine operand.
157 unsigned ARMCodeEmitter::getShiftOp(const MachineOperand &MO) const {
158 switch (ARM_AM::getAM2ShiftOpc(MO.getImm())) {
159 default: assert(0 && "Unknown shift opc!");
160 case ARM_AM::asr: return 2;
161 case ARM_AM::lsl: return 0;
162 case ARM_AM::lsr: return 1;
164 case ARM_AM::rrx: return 3;
169 /// getMachineOpValue - Return binary encoding of operand. If the machine
170 /// operand requires relocation, record the relocation and return zero.
171 unsigned ARMCodeEmitter::getMachineOpValue(const MachineInstr &MI,
172 const MachineOperand &MO) {
174 return ARMRegisterInfo::getRegisterNumbering(MO.getReg());
175 else if (MO.isImmediate())
176 return static_cast<unsigned>(MO.getImm());
177 else if (MO.isGlobalAddress())
178 emitGlobalAddressForCall(MO.getGlobal(), false);
179 else if (MO.isExternalSymbol())
180 emitExternalSymbolAddress(MO.getSymbolName(), ARM::reloc_arm_relative);
181 else if (MO.isConstantPoolIndex())
182 emitConstPoolAddress(MO.getIndex(), ARM::reloc_arm_relative);
183 else if (MO.isJumpTableIndex())
184 emitJumpTableAddress(MO.getIndex(), ARM::reloc_arm_relative);
185 else if (MO.isMachineBasicBlock())
186 emitMachineBasicBlock(MO.getMBB());
192 /// emitGlobalAddressForCall - Emit the specified address to the code stream
193 /// assuming this is part of a function call, which is PC relative.
195 void ARMCodeEmitter::emitGlobalAddressForCall(GlobalValue *GV,
196 bool DoesntNeedStub) {
197 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(),
198 ARM::reloc_arm_branch, GV, 0,
202 /// emitExternalSymbolAddress - Arrange for the address of an external symbol to
203 /// be emitted to the current location in the function, and allow it to be PC
205 void ARMCodeEmitter::emitExternalSymbolAddress(const char *ES, unsigned Reloc) {
206 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
210 /// emitConstPoolAddress - Arrange for the address of an constant pool
211 /// to be emitted to the current location in the function, and allow it to be PC
213 void ARMCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc,
215 unsigned PCAdj /* = 0 */) {
216 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
220 /// emitJumpTableAddress - Arrange for the address of a jump table to
221 /// be emitted to the current location in the function, and allow it to be PC
223 void ARMCodeEmitter::emitJumpTableAddress(unsigned JTI, unsigned Reloc,
224 unsigned PCAdj /* = 0 */) {
225 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
229 /// emitMachineBasicBlock - Emit the specified address basic block.
230 void ARMCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB) {
231 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
232 ARM::reloc_arm_branch, BB));
235 void ARMCodeEmitter::emitInstruction(const MachineInstr &MI) {
238 NumEmitted++; // Keep track of the # of mi's emitted
239 MCE.emitWordLE(getInstrBinary(MI));
242 unsigned ARMCodeEmitter::getAddrModeNoneInstrBinary(const MachineInstr &MI,
243 const TargetInstrDesc &TID,
245 switch (TID.TSFlags & ARMII::FormMask) {
247 assert(0 && "Unknown instruction subtype!");
249 case ARMII::Branch: {
250 // Set signed_immed_24 field
251 Binary |= getMachineOpValue(MI, 0);
253 // if it is a conditional branch, set cond field
254 if (TID.Opcode == ARM::Bcc) {
255 Binary &= 0x0FFFFFFF; // clear conditional field
256 Binary |= getMachineOpValue(MI, 1) << 28; // set conditional field
260 case ARMII::BranchMisc: {
261 // Set bit[19:8] to 0xFFF
262 Binary |= 0xfff << 8;
263 if (TID.Opcode == ARM::BX_RET)
264 Binary |= 0xe; // the return register is LR
266 // otherwise, set the return register
267 Binary |= getMachineOpValue(MI, 0);
275 unsigned ARMCodeEmitter::getMachineSoRegOpValue(const MachineInstr &MI,
276 const TargetInstrDesc &TID,
278 // Set last operand (register Rm)
279 unsigned Binary = getMachineOpValue(MI, OpIdx);
281 const MachineOperand &MO1 = MI.getOperand(OpIdx + 1);
282 const MachineOperand &MO2 = MI.getOperand(OpIdx + 2);
283 ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
285 // Encode the shift opcode.
287 unsigned Rs = MO1.getReg();
289 // Set shift operand (bit[7:4]).
294 // RRX - 0110 and bit[11:8] clear.
296 default: assert(0 && "Unknown shift opc!");
297 case ARM_AM::lsl: SBits = 0x1; break;
298 case ARM_AM::lsr: SBits = 0x3; break;
299 case ARM_AM::asr: SBits = 0x5; break;
300 case ARM_AM::ror: SBits = 0x7; break;
301 case ARM_AM::rrx: SBits = 0x6; break;
304 // Set shift operand (bit[6:4]).
310 default: assert(0 && "Unknown shift opc!");
311 case ARM_AM::lsl: SBits = 0x0; break;
312 case ARM_AM::lsr: SBits = 0x2; break;
313 case ARM_AM::asr: SBits = 0x4; break;
314 case ARM_AM::ror: SBits = 0x6; break;
317 Binary |= SBits << 4;
318 if (SOpc == ARM_AM::rrx)
321 // Encode the shift operation Rs or shift_imm (except rrx).
323 // Encode Rs bit[11:8].
324 assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
326 (ARMRegisterInfo::getRegisterNumbering(Rs) << ARMII::RegRsShift);
329 // Encode shift_imm bit[11:7].
330 return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
333 unsigned ARMCodeEmitter::getAddrMode1SBit(const MachineInstr &MI,
334 const TargetInstrDesc &TID) const {
335 for (unsigned i = MI.getNumOperands(), e = TID.getNumOperands(); i != e; --i){
336 const MachineOperand &MO = MI.getOperand(i-1);
337 if (MO.isRegister() && MO.isDef() && MO.getReg() == ARM::CPSR)
338 return 1 << ARMII::S_BitShift;
343 unsigned ARMCodeEmitter::getAddrMode1InstrBinary(const MachineInstr &MI,
344 const TargetInstrDesc &TID,
346 if ((TID.TSFlags & ARMII::FormMask) == ARMII::Pseudo)
349 // Encode S bit if MI modifies CPSR.
350 Binary |= getAddrMode1SBit(MI, TID);
352 // Encode register def if there is one.
353 unsigned NumDefs = TID.getNumDefs();
356 Binary |= getMachineOpValue(MI, OpIdx) << ARMII::RegRdShift;
360 // Encode first non-shifter register operand if ther is one.
361 if ((TID.TSFlags & ARMII::FormMask) != ARMII::UnaryFrm) {
362 Binary |= getMachineOpValue(MI, OpIdx) << ARMII::RegRnShift;
366 // Encode shifter operand.
367 if (TID.getNumOperands() - OpIdx > 1)
369 return Binary | getMachineSoRegOpValue(MI, TID, OpIdx);
371 const MachineOperand &MO = MI.getOperand(OpIdx);
373 // Encode register Rm.
374 return Binary | getMachineOpValue(MI, NumDefs + 1);
377 // Set bit I(25) to identify this is the immediate form of <shifter_op>
378 Binary |= 1 << ARMII::I_BitShift;
379 unsigned SoImm = MO.getImm();
380 // Encode rotate_imm.
381 Binary |= ARM_AM::getSOImmValRot(SoImm) << ARMII::RotImmShift;
383 Binary |= ARM_AM::getSOImmVal(SoImm);
387 unsigned ARMCodeEmitter::getAddrMode2InstrBinary(const MachineInstr &MI,
388 const TargetInstrDesc &TID,
391 Binary |= getMachineOpValue(MI, 0) << ARMII::RegRdShift;
393 // Set second operand
394 Binary |= getMachineOpValue(MI, 1) << ARMII::RegRnShift;
396 const MachineOperand &MO2 = MI.getOperand(2);
397 const MachineOperand &MO3 = MI.getOperand(3);
399 // Set bit U(23) according to signal of immed value (positive or negative).
400 Binary |= ((ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) <<
402 if (!MO2.getReg()) { // is immediate
403 if (ARM_AM::getAM2Offset(MO3.getImm()))
404 // Set the value of offset_12 field
405 Binary |= ARM_AM::getAM2Offset(MO3.getImm());
409 // Set bit I(25), because this is not in immediate enconding.
410 Binary |= 1 << ARMII::I_BitShift;
411 assert(TargetRegisterInfo::isPhysicalRegister(MO2.getReg()));
412 // Set bit[3:0] to the corresponding Rm register
413 Binary |= ARMRegisterInfo::getRegisterNumbering(MO2.getReg());
415 // if this instr is in scaled register offset/index instruction, set
416 // shift_immed(bit[11:7]) and shift(bit[6:5]) fields.
417 if (unsigned ShImm = ARM_AM::getAM2Offset(MO3.getImm())) {
418 Binary |= getShiftOp(MO3) << 5; // shift
419 Binary |= ShImm << 7; // shift_immed
425 unsigned ARMCodeEmitter::getAddrMode3InstrBinary(const MachineInstr &MI,
426 const TargetInstrDesc &TID,
429 Binary |= getMachineOpValue(MI, 0) << ARMII::RegRdShift;
431 // Set second operand
432 Binary |= getMachineOpValue(MI, 1) << ARMII::RegRnShift;
434 const MachineOperand &MO2 = MI.getOperand(2);
435 const MachineOperand &MO3 = MI.getOperand(3);
437 // Set bit U(23) according to signal of immed value (positive or negative)
438 Binary |= ((ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) <<
441 // If this instr is in register offset/index encoding, set bit[3:0]
442 // to the corresponding Rm register.
444 Binary |= ARMRegisterInfo::getRegisterNumbering(MO2.getReg());
448 // if this instr is in immediate offset/index encoding, set bit 22 to 1
449 if (unsigned ImmOffs = ARM_AM::getAM3Offset(MO3.getImm())) {
452 Binary |= (ImmOffs >> 4) << 8; // immedH
453 Binary |= (ImmOffs & ~0xF); // immedL
459 unsigned ARMCodeEmitter::getAddrMode4InstrBinary(const MachineInstr &MI,
460 const TargetInstrDesc &TID,
463 Binary |= getMachineOpValue(MI, 0) << ARMII::RegRnShift;
465 // Set addressing mode by modifying bits U(23) and P(24)
466 // IA - Increment after - bit U = 1 and bit P = 0
467 // IB - Increment before - bit U = 1 and bit P = 1
468 // DA - Decrement after - bit U = 0 and bit P = 0
469 // DB - Decrement before - bit U = 0 and bit P = 1
470 const MachineOperand &MO = MI.getOperand(1);
471 ARM_AM::AMSubMode Mode = ARM_AM::getAM4SubMode(MO.getImm());
473 default: assert(0 && "Unknown addressing sub-mode!");
474 case ARM_AM::da: break;
475 case ARM_AM::db: Binary |= 0x1 << 24; break;
476 case ARM_AM::ia: Binary |= 0x1 << 23; break;
477 case ARM_AM::ib: Binary |= 0x3 << 23; break;
481 if (ARM_AM::getAM4WBFlag(MO.getImm()))
485 for (unsigned i = 4, e = MI.getNumOperands(); i != e; ++i) {
486 const MachineOperand &MO = MI.getOperand(i);
487 if (MO.isRegister() && MO.isImplicit())
489 unsigned RegNum = ARMRegisterInfo::getRegisterNumbering(MO.getReg());
490 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
492 Binary |= 0x1 << RegNum;
498 /// getInstrBinary - Return binary encoding for the specified
499 /// machine instruction.
500 unsigned ARMCodeEmitter::getInstrBinary(const MachineInstr &MI) {
501 // Part of binary is determined by TableGn.
502 unsigned Binary = getBinaryCodeForInstr(MI);
504 const TargetInstrDesc &TID = MI.getDesc();
505 switch (TID.TSFlags & ARMII::AddrModeMask) {
506 case ARMII::AddrModeNone:
507 return getAddrModeNoneInstrBinary(MI, TID, Binary);
508 case ARMII::AddrMode1:
509 return getAddrMode1InstrBinary(MI, TID, Binary);
510 case ARMII::AddrMode2:
511 return getAddrMode2InstrBinary(MI, TID, Binary);
512 case ARMII::AddrMode3:
513 return getAddrMode3InstrBinary(MI, TID, Binary);
514 case ARMII::AddrMode4:
515 return getAddrMode4InstrBinary(MI, TID, Binary);
522 #include "ARMGenCodeEmitter.inc"