1 //===- MipsInstrInfo.cpp - Mips Instruction Information ---------*- C++ -*-===//
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 Mips implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "MipsInstrInfo.h"
15 #include "MipsTargetMachine.h"
16 #include "MipsMachineFunction.h"
17 #include "InstPrinter/MipsInstPrinter.h"
18 #include "llvm/CodeGen/MachineInstrBuilder.h"
19 #include "llvm/CodeGen/MachineRegisterInfo.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/TargetRegistry.h"
22 #include "llvm/ADT/STLExtras.h"
24 #define GET_INSTRINFO_CTOR
25 #include "MipsGenInstrInfo.inc"
29 MipsInstrInfo::MipsInstrInfo(MipsTargetMachine &tm)
30 : MipsGenInstrInfo(Mips::ADJCALLSTACKDOWN, Mips::ADJCALLSTACKUP),
31 TM(tm), IsN64(TM.getSubtarget<MipsSubtarget>().isABI_N64()),
32 RI(*TM.getSubtargetImpl(), *this),
33 UncondBrOpc(TM.getRelocationModel() == Reloc::PIC_ ? Mips::B : Mips::J) {}
35 const MipsRegisterInfo &MipsInstrInfo::getRegisterInfo() const {
39 static bool isZeroImm(const MachineOperand &op) {
40 return op.isImm() && op.getImm() == 0;
43 /// isLoadFromStackSlot - If the specified machine instruction is a direct
44 /// load from a stack slot, return the virtual or physical register number of
45 /// the destination along with the FrameIndex of the loaded stack slot. If
46 /// not, return 0. This predicate must return 0 if the instruction has
47 /// any side effects other than loading from the stack slot.
48 unsigned MipsInstrInfo::
49 isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const
51 unsigned Opc = MI->getOpcode();
53 if ((Opc == Mips::LW) || (Opc == Mips::LW_P8) || (Opc == Mips::LD) ||
54 (Opc == Mips::LD_P8) || (Opc == Mips::LWC1) || (Opc == Mips::LWC1_P8) ||
55 (Opc == Mips::LDC1) || (Opc == Mips::LDC164) ||
56 (Opc == Mips::LDC164_P8)) {
57 if ((MI->getOperand(1).isFI()) && // is a stack slot
58 (MI->getOperand(2).isImm()) && // the imm is zero
59 (isZeroImm(MI->getOperand(2)))) {
60 FrameIndex = MI->getOperand(1).getIndex();
61 return MI->getOperand(0).getReg();
68 /// isStoreToStackSlot - If the specified machine instruction is a direct
69 /// store to a stack slot, return the virtual or physical register number of
70 /// the source reg along with the FrameIndex of the loaded stack slot. If
71 /// not, return 0. This predicate must return 0 if the instruction has
72 /// any side effects other than storing to the stack slot.
73 unsigned MipsInstrInfo::
74 isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const
76 unsigned Opc = MI->getOpcode();
78 if ((Opc == Mips::SW) || (Opc == Mips::SW_P8) || (Opc == Mips::SD) ||
79 (Opc == Mips::SD_P8) || (Opc == Mips::SWC1) || (Opc == Mips::SWC1_P8) ||
80 (Opc == Mips::SDC1) || (Opc == Mips::SDC164) ||
81 (Opc == Mips::SDC164_P8)) {
82 if ((MI->getOperand(1).isFI()) && // is a stack slot
83 (MI->getOperand(2).isImm()) && // the imm is zero
84 (isZeroImm(MI->getOperand(2)))) {
85 FrameIndex = MI->getOperand(1).getIndex();
86 return MI->getOperand(0).getReg();
92 /// insertNoop - If data hazard condition is found insert the target nop
95 insertNoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const
98 BuildMI(MBB, MI, DL, get(Mips::NOP));
102 copyPhysReg(MachineBasicBlock &MBB,
103 MachineBasicBlock::iterator I, DebugLoc DL,
104 unsigned DestReg, unsigned SrcReg,
105 bool KillSrc) const {
106 unsigned Opc = 0, ZeroReg = 0;
108 if (Mips::CPURegsRegClass.contains(DestReg)) { // Copy to CPU Reg.
109 if (Mips::CPURegsRegClass.contains(SrcReg))
110 Opc = Mips::ADDu, ZeroReg = Mips::ZERO;
111 else if (Mips::CCRRegClass.contains(SrcReg))
113 else if (Mips::FGR32RegClass.contains(SrcReg))
115 else if (SrcReg == Mips::HI)
116 Opc = Mips::MFHI, SrcReg = 0;
117 else if (SrcReg == Mips::LO)
118 Opc = Mips::MFLO, SrcReg = 0;
120 else if (Mips::CPURegsRegClass.contains(SrcReg)) { // Copy from CPU Reg.
121 if (Mips::CCRRegClass.contains(DestReg))
123 else if (Mips::FGR32RegClass.contains(DestReg))
125 else if (DestReg == Mips::HI)
126 Opc = Mips::MTHI, DestReg = 0;
127 else if (DestReg == Mips::LO)
128 Opc = Mips::MTLO, DestReg = 0;
130 else if (Mips::FGR32RegClass.contains(DestReg, SrcReg))
132 else if (Mips::AFGR64RegClass.contains(DestReg, SrcReg))
133 Opc = Mips::FMOV_D32;
134 else if (Mips::FGR64RegClass.contains(DestReg, SrcReg))
135 Opc = Mips::FMOV_D64;
136 else if (Mips::CCRRegClass.contains(DestReg, SrcReg))
137 Opc = Mips::MOVCCRToCCR;
138 else if (Mips::CPU64RegsRegClass.contains(DestReg)) { // Copy to CPU64 Reg.
139 if (Mips::CPU64RegsRegClass.contains(SrcReg))
140 Opc = Mips::DADDu, ZeroReg = Mips::ZERO_64;
141 else if (SrcReg == Mips::HI64)
142 Opc = Mips::MFHI64, SrcReg = 0;
143 else if (SrcReg == Mips::LO64)
144 Opc = Mips::MFLO64, SrcReg = 0;
145 else if (Mips::FGR64RegClass.contains(SrcReg))
148 else if (Mips::CPU64RegsRegClass.contains(SrcReg)) { // Copy from CPU64 Reg.
149 if (DestReg == Mips::HI64)
150 Opc = Mips::MTHI64, DestReg = 0;
151 else if (DestReg == Mips::LO64)
152 Opc = Mips::MTLO64, DestReg = 0;
153 else if (Mips::FGR64RegClass.contains(DestReg))
157 assert(Opc && "Cannot copy registers");
159 MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc));
162 MIB.addReg(DestReg, RegState::Define);
168 MIB.addReg(SrcReg, getKillRegState(KillSrc));
171 static MachineMemOperand* GetMemOperand(MachineBasicBlock &MBB, int FI,
173 MachineFunction &MF = *MBB.getParent();
174 MachineFrameInfo &MFI = *MF.getFrameInfo();
175 unsigned Align = MFI.getObjectAlignment(FI);
177 return MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FI), Flag,
178 MFI.getObjectSize(FI), Align);
182 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
183 unsigned SrcReg, bool isKill, int FI,
184 const TargetRegisterClass *RC,
185 const TargetRegisterInfo *TRI) const {
187 if (I != MBB.end()) DL = I->getDebugLoc();
188 MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOStore);
192 if (RC == Mips::CPURegsRegisterClass)
193 Opc = IsN64 ? Mips::SW_P8 : Mips::SW;
194 else if (RC == Mips::CPU64RegsRegisterClass)
195 Opc = IsN64 ? Mips::SD_P8 : Mips::SD;
196 else if (RC == Mips::FGR32RegisterClass)
197 Opc = IsN64 ? Mips::SWC1_P8 : Mips::SWC1;
198 else if (RC == Mips::AFGR64RegisterClass)
200 else if (RC == Mips::FGR64RegisterClass)
201 Opc = IsN64 ? Mips::SDC164_P8 : Mips::SDC164;
203 assert(Opc && "Register class not handled!");
204 BuildMI(MBB, I, DL, get(Opc)).addReg(SrcReg, getKillRegState(isKill))
205 .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
209 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
210 unsigned DestReg, int FI,
211 const TargetRegisterClass *RC,
212 const TargetRegisterInfo *TRI) const
215 if (I != MBB.end()) DL = I->getDebugLoc();
216 MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOLoad);
219 if (RC == Mips::CPURegsRegisterClass)
220 Opc = IsN64 ? Mips::LW_P8 : Mips::LW;
221 else if (RC == Mips::CPU64RegsRegisterClass)
222 Opc = IsN64 ? Mips::LD_P8 : Mips::LD;
223 else if (RC == Mips::FGR32RegisterClass)
224 Opc = IsN64 ? Mips::LWC1_P8 : Mips::LWC1;
225 else if (RC == Mips::AFGR64RegisterClass)
227 else if (RC == Mips::FGR64RegisterClass)
228 Opc = IsN64 ? Mips::LDC164_P8 : Mips::LDC164;
230 assert(Opc && "Register class not handled!");
231 BuildMI(MBB, I, DL, get(Opc), DestReg).addFrameIndex(FI).addImm(0)
236 MipsInstrInfo::emitFrameIndexDebugValue(MachineFunction &MF, int FrameIx,
237 uint64_t Offset, const MDNode *MDPtr,
239 MachineInstrBuilder MIB = BuildMI(MF, DL, get(Mips::DBG_VALUE))
240 .addFrameIndex(FrameIx).addImm(0).addImm(Offset).addMetadata(MDPtr);
244 //===----------------------------------------------------------------------===//
246 //===----------------------------------------------------------------------===//
248 static unsigned GetAnalyzableBrOpc(unsigned Opc) {
249 return (Opc == Mips::BEQ || Opc == Mips::BNE || Opc == Mips::BGTZ ||
250 Opc == Mips::BGEZ || Opc == Mips::BLTZ || Opc == Mips::BLEZ ||
251 Opc == Mips::BEQ64 || Opc == Mips::BNE64 || Opc == Mips::BGTZ64 ||
252 Opc == Mips::BGEZ64 || Opc == Mips::BLTZ64 || Opc == Mips::BLEZ64 ||
253 Opc == Mips::BC1T || Opc == Mips::BC1F || Opc == Mips::B ||
258 /// GetOppositeBranchOpc - Return the inverse of the specified
259 /// opcode, e.g. turning BEQ to BNE.
260 unsigned Mips::GetOppositeBranchOpc(unsigned Opc)
263 default: llvm_unreachable("Illegal opcode!");
264 case Mips::BEQ: return Mips::BNE;
265 case Mips::BNE: return Mips::BEQ;
266 case Mips::BGTZ: return Mips::BLEZ;
267 case Mips::BGEZ: return Mips::BLTZ;
268 case Mips::BLTZ: return Mips::BGEZ;
269 case Mips::BLEZ: return Mips::BGTZ;
270 case Mips::BEQ64: return Mips::BNE64;
271 case Mips::BNE64: return Mips::BEQ64;
272 case Mips::BGTZ64: return Mips::BLEZ64;
273 case Mips::BGEZ64: return Mips::BLTZ64;
274 case Mips::BLTZ64: return Mips::BGEZ64;
275 case Mips::BLEZ64: return Mips::BGTZ64;
276 case Mips::BC1T: return Mips::BC1F;
277 case Mips::BC1F: return Mips::BC1T;
281 static void AnalyzeCondBr(const MachineInstr* Inst, unsigned Opc,
282 MachineBasicBlock *&BB,
283 SmallVectorImpl<MachineOperand>& Cond) {
284 assert(GetAnalyzableBrOpc(Opc) && "Not an analyzable branch");
285 int NumOp = Inst->getNumExplicitOperands();
287 // for both int and fp branches, the last explicit operand is the
289 BB = Inst->getOperand(NumOp-1).getMBB();
290 Cond.push_back(MachineOperand::CreateImm(Opc));
292 for (int i=0; i<NumOp-1; i++)
293 Cond.push_back(Inst->getOperand(i));
296 bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
297 MachineBasicBlock *&TBB,
298 MachineBasicBlock *&FBB,
299 SmallVectorImpl<MachineOperand> &Cond,
300 bool AllowModify) const
302 MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
304 // Skip all the debug instructions.
305 while (I != REnd && I->isDebugValue())
308 if (I == REnd || !isUnpredicatedTerminator(&*I)) {
309 // If this block ends with no branches (it just falls through to its succ)
310 // just return false, leaving TBB/FBB null.
315 MachineInstr *LastInst = &*I;
316 unsigned LastOpc = LastInst->getOpcode();
318 // Not an analyzable branch (must be an indirect jump).
319 if (!GetAnalyzableBrOpc(LastOpc))
322 // Get the second to last instruction in the block.
323 unsigned SecondLastOpc = 0;
324 MachineInstr *SecondLastInst = NULL;
327 SecondLastInst = &*I;
328 SecondLastOpc = GetAnalyzableBrOpc(SecondLastInst->getOpcode());
330 // Not an analyzable branch (must be an indirect jump).
331 if (isUnpredicatedTerminator(SecondLastInst) && !SecondLastOpc)
335 // If there is only one terminator instruction, process it.
336 if (!SecondLastOpc) {
337 // Unconditional branch
338 if (LastOpc == UncondBrOpc) {
339 TBB = LastInst->getOperand(0).getMBB();
343 // Conditional branch
344 AnalyzeCondBr(LastInst, LastOpc, TBB, Cond);
348 // If we reached here, there are two branches.
349 // If there are three terminators, we don't know what sort of block this is.
350 if (++I != REnd && isUnpredicatedTerminator(&*I))
353 // If second to last instruction is an unconditional branch,
354 // analyze it and remove the last instruction.
355 if (SecondLastOpc == UncondBrOpc) {
356 // Return if the last instruction cannot be removed.
360 TBB = SecondLastInst->getOperand(0).getMBB();
361 LastInst->eraseFromParent();
365 // Conditional branch followed by an unconditional branch.
366 // The last one must be unconditional.
367 if (LastOpc != UncondBrOpc)
370 AnalyzeCondBr(SecondLastInst, SecondLastOpc, TBB, Cond);
371 FBB = LastInst->getOperand(0).getMBB();
376 void MipsInstrInfo::BuildCondBr(MachineBasicBlock &MBB,
377 MachineBasicBlock *TBB, DebugLoc DL,
378 const SmallVectorImpl<MachineOperand>& Cond)
380 unsigned Opc = Cond[0].getImm();
381 const MCInstrDesc &MCID = get(Opc);
382 MachineInstrBuilder MIB = BuildMI(&MBB, DL, MCID);
384 for (unsigned i = 1; i < Cond.size(); ++i)
385 MIB.addReg(Cond[i].getReg());
390 unsigned MipsInstrInfo::
391 InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
392 MachineBasicBlock *FBB,
393 const SmallVectorImpl<MachineOperand> &Cond,
395 // Shouldn't be a fall through.
396 assert(TBB && "InsertBranch must not be told to insert a fallthrough");
398 // # of condition operands:
399 // Unconditional branches: 0
400 // Floating point branches: 1 (opc)
401 // Int BranchZero: 2 (opc, reg)
402 // Int Branch: 3 (opc, reg0, reg1)
403 assert((Cond.size() <= 3) &&
404 "# of Mips branch conditions must be <= 3!");
406 // Two-way Conditional branch.
408 BuildCondBr(MBB, TBB, DL, Cond);
409 BuildMI(&MBB, DL, get(UncondBrOpc)).addMBB(FBB);
414 // Unconditional branch.
416 BuildMI(&MBB, DL, get(UncondBrOpc)).addMBB(TBB);
417 else // Conditional branch.
418 BuildCondBr(MBB, TBB, DL, Cond);
422 unsigned MipsInstrInfo::
423 RemoveBranch(MachineBasicBlock &MBB) const
425 MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
426 MachineBasicBlock::reverse_iterator FirstBr;
429 // Skip all the debug instructions.
430 while (I != REnd && I->isDebugValue())
435 // Up to 2 branches are removed.
436 // Note that indirect branches are not removed.
437 for(removed = 0; I != REnd && removed < 2; ++I, ++removed)
438 if (!GetAnalyzableBrOpc(I->getOpcode()))
441 MBB.erase(I.base(), FirstBr.base());
446 /// ReverseBranchCondition - Return the inverse opcode of the
447 /// specified Branch instruction.
449 ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
451 assert( (Cond.size() && Cond.size() <= 3) &&
452 "Invalid Mips branch condition!");
453 Cond[0].setImm(Mips::GetOppositeBranchOpc(Cond[0].getImm()));
457 /// getGlobalBaseReg - Return a virtual register initialized with the
458 /// the global base register value. Output instructions required to
459 /// initialize the register in the function entry block, if necessary.
461 unsigned MipsInstrInfo::getGlobalBaseReg(MachineFunction *MF) const {
462 MipsFunctionInfo *MipsFI = MF->getInfo<MipsFunctionInfo>();
463 unsigned GlobalBaseReg = MipsFI->getGlobalBaseReg();
464 if (GlobalBaseReg != 0)
465 return GlobalBaseReg;
467 // Insert the set of GlobalBaseReg into the first MBB of the function
468 MachineBasicBlock &FirstMBB = MF->front();
469 MachineBasicBlock::iterator MBBI = FirstMBB.begin();
470 MachineRegisterInfo &RegInfo = MF->getRegInfo();
471 const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
473 GlobalBaseReg = RegInfo.createVirtualRegister(Mips::CPURegsRegisterClass);
474 BuildMI(FirstMBB, MBBI, DebugLoc(), TII->get(TargetOpcode::COPY),
475 GlobalBaseReg).addReg(Mips::GP);
476 RegInfo.addLiveIn(Mips::GP);
478 MipsFI->setGlobalBaseReg(GlobalBaseReg);
479 return GlobalBaseReg;