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 "jit"
17 #include "ARMAddressingModes.h"
18 #include "ARMConstantPoolValue.h"
19 #include "ARMInstrInfo.h"
20 #include "ARMRelocations.h"
21 #include "ARMSubtarget.h"
22 #include "ARMTargetMachine.h"
23 #include "llvm/Constants.h"
24 #include "llvm/DerivedTypes.h"
25 #include "llvm/Function.h"
26 #include "llvm/PassManager.h"
27 #include "llvm/CodeGen/MachineCodeEmitter.h"
28 #include "llvm/CodeGen/MachineConstantPool.h"
29 #include "llvm/CodeGen/MachineFunctionPass.h"
30 #include "llvm/CodeGen/MachineInstr.h"
31 #include "llvm/CodeGen/Passes.h"
32 #include "llvm/ADT/Statistic.h"
33 #include "llvm/Support/Compiler.h"
34 #include "llvm/Support/Debug.h"
37 STATISTIC(NumEmitted, "Number of machine instructions emitted");
40 class VISIBILITY_HIDDEN ARMCodeEmitter : public MachineFunctionPass {
42 const ARMInstrInfo *II;
45 MachineCodeEmitter &MCE;
46 const std::vector<MachineConstantPoolEntry> *MCPEs;
50 explicit ARMCodeEmitter(TargetMachine &tm, MachineCodeEmitter &mce)
51 : MachineFunctionPass(&ID), JTI(0), II(0), TD(0), TM(tm),
53 ARMCodeEmitter(TargetMachine &tm, MachineCodeEmitter &mce,
54 const ARMInstrInfo &ii, const TargetData &td)
55 : MachineFunctionPass(&ID), JTI(0), II(&ii), TD(&td), TM(tm),
58 bool runOnMachineFunction(MachineFunction &MF);
60 virtual const char *getPassName() const {
61 return "ARM Machine Code Emitter";
64 void emitInstruction(const MachineInstr &MI);
68 void emitConstPoolInstruction(const MachineInstr &MI);
70 void emitPseudoInstruction(const MachineInstr &MI);
72 unsigned getAddrModeNoneInstrBinary(const MachineInstr &MI,
73 const TargetInstrDesc &TID,
76 unsigned getMachineSoRegOpValue(const MachineInstr &MI,
77 const TargetInstrDesc &TID,
78 const MachineOperand &MO,
81 unsigned getMachineSoImmOpValue(const MachineInstr &MI,
82 const TargetInstrDesc &TID,
83 const MachineOperand &MO);
85 unsigned getAddrMode1SBit(const MachineInstr &MI,
86 const TargetInstrDesc &TID) const;
88 unsigned getAddrMode1InstrBinary(const MachineInstr &MI,
89 const TargetInstrDesc &TID,
91 unsigned getAddrMode2InstrBinary(const MachineInstr &MI,
92 const TargetInstrDesc &TID,
94 unsigned getAddrMode3InstrBinary(const MachineInstr &MI,
95 const TargetInstrDesc &TID,
97 unsigned getAddrMode4InstrBinary(const MachineInstr &MI,
98 const TargetInstrDesc &TID,
101 /// getInstrBinary - Return binary encoding for the specified
102 /// machine instruction.
103 unsigned getInstrBinary(const MachineInstr &MI);
105 /// getBinaryCodeForInstr - This function, generated by the
106 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
107 /// machine instructions.
109 unsigned getBinaryCodeForInstr(const MachineInstr &MI);
111 /// getMachineOpValue - Return binary encoding of operand. If the machine
112 /// operand requires relocation, record the relocation and return zero.
113 unsigned getMachineOpValue(const MachineInstr &MI,const MachineOperand &MO);
114 unsigned getMachineOpValue(const MachineInstr &MI, unsigned OpIdx) {
115 return getMachineOpValue(MI, MI.getOperand(OpIdx));
118 /// getBaseOpcodeFor - Return the opcode value.
120 unsigned getBaseOpcodeFor(const TargetInstrDesc &TID) const {
121 return (TID.TSFlags & ARMII::OpcodeMask) >> ARMII::OpcodeShift;
124 /// getShiftOp - Return the shift opcode (bit[6:5]) of the machine operand.
126 unsigned getShiftOp(const MachineOperand &MO) const ;
128 /// Routines that handle operands which add machine relocations which are
129 /// fixed up by the JIT fixup stage.
130 void emitGlobalAddress(GlobalValue *GV, unsigned Reloc,
132 void emitExternalSymbolAddress(const char *ES, unsigned Reloc);
133 void emitConstPoolAddress(unsigned CPI, unsigned Reloc,
134 int Disp = 0, unsigned PCAdj = 0 );
135 void emitJumpTableAddress(unsigned JTIndex, unsigned Reloc,
137 void emitGlobalConstant(const Constant *CV);
138 void emitMachineBasicBlock(MachineBasicBlock *BB);
140 char ARMCodeEmitter::ID = 0;
143 /// createARMCodeEmitterPass - Return a pass that emits the collected ARM code
144 /// to the specified MCE object.
145 FunctionPass *llvm::createARMCodeEmitterPass(ARMTargetMachine &TM,
146 MachineCodeEmitter &MCE) {
147 return new ARMCodeEmitter(TM, MCE);
150 bool ARMCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
151 assert((MF.getTarget().getRelocationModel() != Reloc::Default ||
152 MF.getTarget().getRelocationModel() != Reloc::Static) &&
153 "JIT relocation model must be set to static or default!");
154 II = ((ARMTargetMachine&)MF.getTarget()).getInstrInfo();
155 TD = ((ARMTargetMachine&)MF.getTarget()).getTargetData();
156 JTI = ((ARMTargetMachine&)MF.getTarget()).getJITInfo();
157 MCPEs = &MF.getConstantPool()->getConstants();
158 JTI->ResizeConstPoolMap(MCPEs->size());
161 DOUT << "JITTing function '" << MF.getFunction()->getName() << "'\n";
162 MCE.startFunction(MF);
163 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
165 MCE.StartMachineBasicBlock(MBB);
166 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
170 } while (MCE.finishFunction(MF));
175 /// getShiftOp - Return the shift opcode (bit[6:5]) of the machine operand.
177 unsigned ARMCodeEmitter::getShiftOp(const MachineOperand &MO) const {
178 switch (ARM_AM::getAM2ShiftOpc(MO.getImm())) {
179 default: assert(0 && "Unknown shift opc!");
180 case ARM_AM::asr: return 2;
181 case ARM_AM::lsl: return 0;
182 case ARM_AM::lsr: return 1;
184 case ARM_AM::rrx: return 3;
189 /// getMachineOpValue - Return binary encoding of operand. If the machine
190 /// operand requires relocation, record the relocation and return zero.
191 unsigned ARMCodeEmitter::getMachineOpValue(const MachineInstr &MI,
192 const MachineOperand &MO) {
194 return ARMRegisterInfo::getRegisterNumbering(MO.getReg());
196 return static_cast<unsigned>(MO.getImm());
197 else if (MO.isGlobal())
198 emitGlobalAddress(MO.getGlobal(), ARM::reloc_arm_branch, true);
199 else if (MO.isSymbol())
200 emitExternalSymbolAddress(MO.getSymbolName(), ARM::reloc_arm_relative);
202 emitConstPoolAddress(MO.getIndex(), ARM::reloc_arm_cp_entry);
204 emitJumpTableAddress(MO.getIndex(), ARM::reloc_arm_relative);
206 emitMachineBasicBlock(MO.getMBB());
208 cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
214 /// emitGlobalAddress - Emit the specified address to the code stream.
216 void ARMCodeEmitter::emitGlobalAddress(GlobalValue *GV,
217 unsigned Reloc, bool NeedStub) {
218 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(),
219 Reloc, GV, 0, NeedStub));
222 /// emitExternalSymbolAddress - Arrange for the address of an external symbol to
223 /// be emitted to the current location in the function, and allow it to be PC
225 void ARMCodeEmitter::emitExternalSymbolAddress(const char *ES, unsigned Reloc) {
226 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
230 /// emitConstPoolAddress - Arrange for the address of an constant pool
231 /// to be emitted to the current location in the function, and allow it to be PC
233 void ARMCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc,
235 unsigned PCAdj /* = 0 */) {
236 // Tell JIT emitter we'll resolve the address.
237 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
238 Reloc, CPI, PCAdj, true));
241 /// emitJumpTableAddress - Arrange for the address of a jump table to
242 /// be emitted to the current location in the function, and allow it to be PC
244 void ARMCodeEmitter::emitJumpTableAddress(unsigned JTIndex, unsigned Reloc,
245 unsigned PCAdj /* = 0 */) {
246 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
247 Reloc, JTIndex, PCAdj));
250 /// emitMachineBasicBlock - Emit the specified address basic block.
251 void ARMCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB) {
252 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
253 ARM::reloc_arm_branch, BB));
256 void ARMCodeEmitter::emitInstruction(const MachineInstr &MI) {
257 DOUT << "JIT: " << "0x" << MCE.getCurrentPCValue() << ":\t" << MI;
259 NumEmitted++; // Keep track of the # of mi's emitted
260 if ((MI.getDesc().TSFlags & ARMII::FormMask) == ARMII::Pseudo)
261 emitPseudoInstruction(MI);
263 MCE.emitWordLE(getInstrBinary(MI));
266 void ARMCodeEmitter::emitConstPoolInstruction(const MachineInstr &MI) {
267 unsigned CPI = MI.getOperand(0).getImm();
268 unsigned CPIndex = MI.getOperand(1).getIndex();
269 const MachineConstantPoolEntry &MCPE = (*MCPEs)[CPIndex];
271 // Remember the CONSTPOOL_ENTRY address for later relocation.
272 JTI->addConstantPoolEntryAddr(CPI, MCE.getCurrentPCValue());
274 // Emit constpool island entry. In most cases, the actual values will be
275 // resolved and relocated after code emission.
276 if (MCPE.isMachineConstantPoolEntry()) {
277 ARMConstantPoolValue *ACPV =
278 static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
280 DOUT << "\t** ARM constant pool #" << CPI << " @ "
281 << (void*)MCE.getCurrentPCValue() << " '" << *ACPV << "'\n";
283 GlobalValue *GV = ACPV->getGV();
285 assert(!ACPV->isStub() && "Don't know how to deal this yet!");
286 emitGlobalAddress(GV, ARM::reloc_arm_absolute, false);
288 assert(!ACPV->isNonLazyPointer() && "Don't know how to deal this yet!");
289 emitExternalSymbolAddress(ACPV->getSymbol(), ARM::reloc_arm_absolute);
293 Constant *CV = MCPE.Val.ConstVal;
295 DOUT << "\t** Constant pool #" << CPI << " @ "
296 << (void*)MCE.getCurrentPCValue() << " '" << *CV << "'\n";
298 if (GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
299 emitGlobalAddress(GV, ARM::reloc_arm_absolute, false);
302 assert(CV->getType()->isInteger() &&
303 "Not expecting non-integer constpool entries yet!");
304 const ConstantInt *CI = dyn_cast<ConstantInt>(CV);
305 uint32_t Val = *(uint32_t*)CI->getValue().getRawData();
311 void ARMCodeEmitter::emitPseudoInstruction(const MachineInstr &MI) {
312 unsigned Opcode = MI.getDesc().Opcode;
316 case ARM::CONSTPOOL_ENTRY:
317 emitConstPoolInstruction(MI);
320 // PICADD is just an add instruction that implicitly read pc.
321 unsigned Binary = getBinaryCodeForInstr(MI);
322 const TargetInstrDesc &TID = MI.getDesc();
323 MCE.emitWordLE(getAddrMode1InstrBinary(MI, TID, Binary));
330 unsigned ARMCodeEmitter::getAddrModeNoneInstrBinary(const MachineInstr &MI,
331 const TargetInstrDesc &TID,
333 // Set the conditional execution predicate
334 Binary |= II->getPredicate(&MI) << 28;
336 switch (TID.TSFlags & ARMII::FormMask) {
338 assert(0 && "Unknown instruction subtype!");
340 case ARMII::Branch: {
341 // Set signed_immed_24 field
342 Binary |= getMachineOpValue(MI, 0);
344 // if it is a conditional branch, set cond field
345 if (TID.Opcode == ARM::Bcc) {
346 Binary &= 0x0FFFFFFF; // clear conditional field
347 Binary |= getMachineOpValue(MI, 1) << 28; // set conditional field
351 case ARMII::BranchMisc: {
352 if (TID.Opcode == ARM::BX)
354 if (TID.Opcode == ARM::BX_RET)
355 Binary |= 0xe; // the return register is LR
357 // otherwise, set the return register
358 Binary |= getMachineOpValue(MI, 0);
366 unsigned ARMCodeEmitter::getMachineSoRegOpValue(const MachineInstr &MI,
367 const TargetInstrDesc &TID,
368 const MachineOperand &MO,
370 unsigned Binary = getMachineOpValue(MI, MO);
372 const MachineOperand &MO1 = MI.getOperand(OpIdx + 1);
373 const MachineOperand &MO2 = MI.getOperand(OpIdx + 2);
374 ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
376 // Encode the shift opcode.
378 unsigned Rs = MO1.getReg();
380 // Set shift operand (bit[7:4]).
385 // RRX - 0110 and bit[11:8] clear.
387 default: assert(0 && "Unknown shift opc!");
388 case ARM_AM::lsl: SBits = 0x1; break;
389 case ARM_AM::lsr: SBits = 0x3; break;
390 case ARM_AM::asr: SBits = 0x5; break;
391 case ARM_AM::ror: SBits = 0x7; break;
392 case ARM_AM::rrx: SBits = 0x6; break;
395 // Set shift operand (bit[6:4]).
401 default: assert(0 && "Unknown shift opc!");
402 case ARM_AM::lsl: SBits = 0x0; break;
403 case ARM_AM::lsr: SBits = 0x2; break;
404 case ARM_AM::asr: SBits = 0x4; break;
405 case ARM_AM::ror: SBits = 0x6; break;
408 Binary |= SBits << 4;
409 if (SOpc == ARM_AM::rrx)
412 // Encode the shift operation Rs or shift_imm (except rrx).
414 // Encode Rs bit[11:8].
415 assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
417 (ARMRegisterInfo::getRegisterNumbering(Rs) << ARMII::RegRsShift);
420 // Encode shift_imm bit[11:7].
421 return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
424 unsigned ARMCodeEmitter::getMachineSoImmOpValue(const MachineInstr &MI,
425 const TargetInstrDesc &TID,
426 const MachineOperand &MO) {
427 unsigned SoImm = MO.getImm();
428 // Encode rotate_imm.
429 unsigned Binary = ARM_AM::getSOImmValRot(SoImm) << ARMII::RotImmShift;
431 Binary |= ARM_AM::getSOImmVal(SoImm);
435 unsigned ARMCodeEmitter::getAddrMode1SBit(const MachineInstr &MI,
436 const TargetInstrDesc &TID) const {
437 for (unsigned i = MI.getNumOperands(), e = TID.getNumOperands(); i != e; --i){
438 const MachineOperand &MO = MI.getOperand(i-1);
439 if (MO.isReg() && MO.isDef() && MO.getReg() == ARM::CPSR)
440 return 1 << ARMII::S_BitShift;
445 unsigned ARMCodeEmitter::getAddrMode1InstrBinary(const MachineInstr &MI,
446 const TargetInstrDesc &TID,
448 // Set the conditional execution predicate
449 Binary |= II->getPredicate(&MI) << 28;
451 // Encode S bit if MI modifies CPSR.
452 Binary |= getAddrMode1SBit(MI, TID);
454 // Encode register def if there is one.
455 unsigned NumDefs = TID.getNumDefs();
458 Binary |= getMachineOpValue(MI, OpIdx) << ARMII::RegRdShift;
462 // Encode first non-shifter register operand if there is one.
463 unsigned Format = TID.TSFlags & ARMII::FormMask;
464 bool HasRnReg = !(Format == ARMII::DPRdMisc ||
465 Format == ARMII::DPRdIm ||
466 Format == ARMII::DPRdReg ||
467 Format == ARMII::DPRdSoReg);
469 if (TID.getOpcode() == ARM::PICADD)
470 // Special handling for PICADD. It implicitly use add.
472 ARMRegisterInfo::getRegisterNumbering(ARM::PC) << ARMII::RegRnShift;
474 Binary |= getMachineOpValue(MI, OpIdx) << ARMII::RegRnShift;
479 // Encode shifter operand.
480 bool HasSoReg = (Format == ARMII::DPRdSoReg ||
481 Format == ARMII::DPRnSoReg ||
482 Format == ARMII::DPRSoReg ||
483 Format == ARMII::DPRSoRegS);
485 const MachineOperand &MO = MI.getOperand(OpIdx);
488 return Binary | getMachineSoRegOpValue(MI, TID, MO, OpIdx);
491 // Encode register Rm.
492 return Binary | ARMRegisterInfo::getRegisterNumbering(MO.getReg());
495 // Set bit I(25) to identify this is the immediate form of <shifter_op>
496 Binary |= 1 << ARMII::I_BitShift;
497 Binary |= getMachineSoImmOpValue(MI, TID, MO);
501 unsigned ARMCodeEmitter::getAddrMode2InstrBinary(const MachineInstr &MI,
502 const TargetInstrDesc &TID,
504 // Set the conditional execution predicate
505 Binary |= II->getPredicate(&MI) << 28;
508 Binary |= getMachineOpValue(MI, 0) << ARMII::RegRdShift;
510 // Set second operand
511 Binary |= getMachineOpValue(MI, 1) << ARMII::RegRnShift;
513 const MachineOperand &MO2 = MI.getOperand(2);
514 const MachineOperand &MO3 = MI.getOperand(3);
516 // Set bit U(23) according to sign of immed value (positive or negative).
517 Binary |= ((ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) <<
519 if (!MO2.getReg()) { // is immediate
520 if (ARM_AM::getAM2Offset(MO3.getImm()))
521 // Set the value of offset_12 field
522 Binary |= ARM_AM::getAM2Offset(MO3.getImm());
526 // Set bit I(25), because this is not in immediate enconding.
527 Binary |= 1 << ARMII::I_BitShift;
528 assert(TargetRegisterInfo::isPhysicalRegister(MO2.getReg()));
529 // Set bit[3:0] to the corresponding Rm register
530 Binary |= ARMRegisterInfo::getRegisterNumbering(MO2.getReg());
532 // if this instr is in scaled register offset/index instruction, set
533 // shift_immed(bit[11:7]) and shift(bit[6:5]) fields.
534 if (unsigned ShImm = ARM_AM::getAM2Offset(MO3.getImm())) {
535 Binary |= getShiftOp(MO3) << 5; // shift
536 Binary |= ShImm << 7; // shift_immed
542 unsigned ARMCodeEmitter::getAddrMode3InstrBinary(const MachineInstr &MI,
543 const TargetInstrDesc &TID,
545 // Set the conditional execution predicate
546 Binary |= II->getPredicate(&MI) << 28;
549 Binary |= getMachineOpValue(MI, 0) << ARMII::RegRdShift;
551 // Set second operand
552 Binary |= getMachineOpValue(MI, 1) << ARMII::RegRnShift;
554 const MachineOperand &MO2 = MI.getOperand(2);
555 const MachineOperand &MO3 = MI.getOperand(3);
557 // Set bit U(23) according to sign of immed value (positive or negative)
558 Binary |= ((ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) <<
561 // If this instr is in register offset/index encoding, set bit[3:0]
562 // to the corresponding Rm register.
564 Binary |= ARMRegisterInfo::getRegisterNumbering(MO2.getReg());
568 // if this instr is in immediate offset/index encoding, set bit 22 to 1
569 if (unsigned ImmOffs = ARM_AM::getAM3Offset(MO3.getImm())) {
572 Binary |= (ImmOffs >> 4) << 8; // immedH
573 Binary |= (ImmOffs & ~0xF); // immedL
579 unsigned ARMCodeEmitter::getAddrMode4InstrBinary(const MachineInstr &MI,
580 const TargetInstrDesc &TID,
582 // Set the conditional execution predicate
583 Binary |= II->getPredicate(&MI) << 28;
586 Binary |= getMachineOpValue(MI, 0) << ARMII::RegRnShift;
588 // Set addressing mode by modifying bits U(23) and P(24)
589 // IA - Increment after - bit U = 1 and bit P = 0
590 // IB - Increment before - bit U = 1 and bit P = 1
591 // DA - Decrement after - bit U = 0 and bit P = 0
592 // DB - Decrement before - bit U = 0 and bit P = 1
593 const MachineOperand &MO = MI.getOperand(1);
594 ARM_AM::AMSubMode Mode = ARM_AM::getAM4SubMode(MO.getImm());
596 default: assert(0 && "Unknown addressing sub-mode!");
597 case ARM_AM::da: break;
598 case ARM_AM::db: Binary |= 0x1 << 24; break;
599 case ARM_AM::ia: Binary |= 0x1 << 23; break;
600 case ARM_AM::ib: Binary |= 0x3 << 23; break;
604 if (ARM_AM::getAM4WBFlag(MO.getImm()))
608 for (unsigned i = 4, e = MI.getNumOperands(); i != e; ++i) {
609 const MachineOperand &MO = MI.getOperand(i);
610 if (MO.isReg() && MO.isImplicit())
612 unsigned RegNum = ARMRegisterInfo::getRegisterNumbering(MO.getReg());
613 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
615 Binary |= 0x1 << RegNum;
621 /// getInstrBinary - Return binary encoding for the specified
622 /// machine instruction.
623 unsigned ARMCodeEmitter::getInstrBinary(const MachineInstr &MI) {
624 // Part of binary is determined by TableGn.
625 unsigned Binary = getBinaryCodeForInstr(MI);
627 const TargetInstrDesc &TID = MI.getDesc();
628 switch (TID.TSFlags & ARMII::AddrModeMask) {
629 case ARMII::AddrModeNone:
630 return getAddrModeNoneInstrBinary(MI, TID, Binary);
631 case ARMII::AddrMode1:
632 return getAddrMode1InstrBinary(MI, TID, Binary);
633 case ARMII::AddrMode2:
634 return getAddrMode2InstrBinary(MI, TID, Binary);
635 case ARMII::AddrMode3:
636 return getAddrMode3InstrBinary(MI, TID, Binary);
637 case ARMII::AddrMode4:
638 return getAddrMode4InstrBinary(MI, TID, Binary);
645 #include "ARMGenCodeEmitter.inc"