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 "llvm/ADT/STLExtras.h"
17 #include "llvm/CodeGen/MachineInstrBuilder.h"
18 #include "MipsGenInstrInfo.inc"
22 MipsInstrInfo::MipsInstrInfo(MipsTargetMachine &tm)
23 : TargetInstrInfoImpl(MipsInsts, array_lengthof(MipsInsts)),
24 TM(tm), RI(*TM.getSubtargetImpl(), *this) {}
26 static bool isZeroImm(const MachineOperand &op) {
27 return op.isImm() && op.getImm() == 0;
30 /// Return true if the instruction is a register to register move and
31 /// leave the source and dest operands in the passed parameters.
33 isMoveInstr(const MachineInstr &MI, unsigned &SrcReg, unsigned &DstReg,
34 unsigned &SrcSubIdx, unsigned &DstSubIdx) const
36 SrcSubIdx = DstSubIdx = 0; // No sub-registers.
38 // addu $dst, $src, $zero || addu $dst, $zero, $src
39 // or $dst, $src, $zero || or $dst, $zero, $src
40 if ((MI.getOpcode() == Mips::ADDu) || (MI.getOpcode() == Mips::OR)) {
41 if (MI.getOperand(1).getReg() == Mips::ZERO) {
42 DstReg = MI.getOperand(0).getReg();
43 SrcReg = MI.getOperand(2).getReg();
45 } else if (MI.getOperand(2).getReg() == Mips::ZERO) {
46 DstReg = MI.getOperand(0).getReg();
47 SrcReg = MI.getOperand(1).getReg();
55 if (MI.getOpcode() == Mips::FMOV_SO32 || MI.getOpcode() == Mips::FMOV_AS32 ||
56 MI.getOpcode() == Mips::FMOV_D32 || MI.getOpcode() == Mips::MFC1A ||
57 MI.getOpcode() == Mips::MFC1 || MI.getOpcode() == Mips::MTC1A ||
58 MI.getOpcode() == Mips::MTC1 ) {
59 DstReg = MI.getOperand(0).getReg();
60 SrcReg = MI.getOperand(1).getReg();
64 // addiu $dst, $src, 0
65 if (MI.getOpcode() == Mips::ADDiu) {
66 if ((MI.getOperand(1).isReg()) && (isZeroImm(MI.getOperand(2)))) {
67 DstReg = MI.getOperand(0).getReg();
68 SrcReg = MI.getOperand(1).getReg();
75 /// isLoadFromStackSlot - If the specified machine instruction is a direct
76 /// load from a stack slot, return the virtual or physical register number of
77 /// the destination along with the FrameIndex of the loaded stack slot. If
78 /// not, return 0. This predicate must return 0 if the instruction has
79 /// any side effects other than loading from the stack slot.
80 unsigned MipsInstrInfo::
81 isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const
83 if ((MI->getOpcode() == Mips::LW) || (MI->getOpcode() == Mips::LWC1) ||
84 (MI->getOpcode() == Mips::LWC1A) || (MI->getOpcode() == Mips::LDC1)) {
85 if ((MI->getOperand(2).isFI()) && // is a stack slot
86 (MI->getOperand(1).isImm()) && // the imm is zero
87 (isZeroImm(MI->getOperand(1)))) {
88 FrameIndex = MI->getOperand(2).getIndex();
89 return MI->getOperand(0).getReg();
96 /// isStoreToStackSlot - If the specified machine instruction is a direct
97 /// store to a stack slot, return the virtual or physical register number of
98 /// the source reg along with the FrameIndex of the loaded stack slot. If
99 /// not, return 0. This predicate must return 0 if the instruction has
100 /// any side effects other than storing to the stack slot.
101 unsigned MipsInstrInfo::
102 isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const
104 if ((MI->getOpcode() == Mips::SW) || (MI->getOpcode() == Mips::SWC1) ||
105 (MI->getOpcode() == Mips::SWC1A) || (MI->getOpcode() == Mips::SDC1)) {
106 if ((MI->getOperand(2).isFI()) && // is a stack slot
107 (MI->getOperand(1).isImm()) && // the imm is zero
108 (isZeroImm(MI->getOperand(1)))) {
109 FrameIndex = MI->getOperand(2).getIndex();
110 return MI->getOperand(0).getReg();
116 /// insertNoop - If data hazard condition is found insert the target nop
119 insertNoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const
121 BuildMI(MBB, MI, get(Mips::NOP));
125 copyRegToReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
126 unsigned DestReg, unsigned SrcReg,
127 const TargetRegisterClass *DestRC,
128 const TargetRegisterClass *SrcRC) const {
129 if (DestRC != SrcRC) {
130 if ((DestRC == Mips::CPURegsRegisterClass) &&
131 (SrcRC == Mips::FGR32RegisterClass))
132 BuildMI(MBB, I, get(Mips::MFC1), DestReg).addReg(SrcReg);
133 else if ((DestRC == Mips::CPURegsRegisterClass) &&
134 (SrcRC == Mips::AFGR32RegisterClass))
135 BuildMI(MBB, I, get(Mips::MFC1A), DestReg).addReg(SrcReg);
136 else if ((DestRC == Mips::FGR32RegisterClass) &&
137 (SrcRC == Mips::CPURegsRegisterClass))
138 BuildMI(MBB, I, get(Mips::MTC1), DestReg).addReg(SrcReg);
139 else if ((DestRC == Mips::AFGR32RegisterClass) &&
140 (SrcRC == Mips::CPURegsRegisterClass))
141 BuildMI(MBB, I, get(Mips::MTC1A), DestReg).addReg(SrcReg);
142 else if ((DestRC == Mips::AFGR32RegisterClass) &&
143 (SrcRC == Mips::CPURegsRegisterClass))
144 BuildMI(MBB, I, get(Mips::MTC1A), DestReg).addReg(SrcReg);
145 else if ((SrcRC == Mips::CCRRegisterClass) &&
146 (SrcReg == Mips::FCR31))
147 return true; // This register is used implicitly, no copy needed.
148 else if ((DestRC == Mips::CCRRegisterClass) &&
149 (DestReg == Mips::FCR31))
150 return true; // This register is used implicitly, no copy needed.
151 else if ((DestRC == Mips::HILORegisterClass) &&
152 (SrcRC == Mips::CPURegsRegisterClass)) {
153 unsigned Opc = (DestReg == Mips::HI) ? Mips::MTHI : Mips::MTLO;
154 BuildMI(MBB, I, get(Opc), DestReg);
155 } else if ((SrcRC == Mips::HILORegisterClass) &&
156 (DestRC == Mips::CPURegsRegisterClass)) {
157 unsigned Opc = (SrcReg == Mips::HI) ? Mips::MFHI : Mips::MFLO;
158 BuildMI(MBB, I, get(Opc), DestReg);
160 // DestRC != SrcRC, Can't copy this register
166 if (DestRC == Mips::CPURegsRegisterClass)
167 BuildMI(MBB, I, get(Mips::ADDu), DestReg).addReg(Mips::ZERO)
169 else if (DestRC == Mips::FGR32RegisterClass)
170 BuildMI(MBB, I, get(Mips::FMOV_SO32), DestReg).addReg(SrcReg);
171 else if (DestRC == Mips::AFGR32RegisterClass)
172 BuildMI(MBB, I, get(Mips::FMOV_AS32), DestReg).addReg(SrcReg);
173 else if (DestRC == Mips::AFGR64RegisterClass)
174 BuildMI(MBB, I, get(Mips::FMOV_D32), DestReg).addReg(SrcReg);
176 // Can't copy this register
183 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
184 unsigned SrcReg, bool isKill, int FI,
185 const TargetRegisterClass *RC) const
188 if (RC == Mips::CPURegsRegisterClass)
190 else if (RC == Mips::FGR32RegisterClass)
192 else if (RC == Mips::AFGR32RegisterClass)
194 else if (RC == Mips::AFGR64RegisterClass)
197 assert(0 && "Can't store this register to stack slot");
199 BuildMI(MBB, I, get(Opc)).addReg(SrcReg, false, false, isKill)
200 .addImm(0).addFrameIndex(FI);
203 void MipsInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
204 bool isKill, SmallVectorImpl<MachineOperand> &Addr,
205 const TargetRegisterClass *RC, SmallVectorImpl<MachineInstr*> &NewMIs) const
208 if (RC == Mips::CPURegsRegisterClass)
210 else if (RC == Mips::FGR32RegisterClass)
212 else if (RC == Mips::AFGR32RegisterClass)
214 else if (RC == Mips::AFGR64RegisterClass)
217 assert(0 && "Can't store this register");
219 MachineInstrBuilder MIB = BuildMI(MF, get(Opc))
220 .addReg(SrcReg, false, false, isKill);
221 for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
222 MachineOperand &MO = Addr[i];
224 MIB.addReg(MO.getReg());
226 MIB.addImm(MO.getImm());
228 MIB.addFrameIndex(MO.getIndex());
230 NewMIs.push_back(MIB);
235 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
236 unsigned DestReg, int FI,
237 const TargetRegisterClass *RC) const
240 if (RC == Mips::CPURegsRegisterClass)
242 else if (RC == Mips::FGR32RegisterClass)
244 else if (RC == Mips::AFGR32RegisterClass)
246 else if (RC == Mips::AFGR64RegisterClass)
249 assert(0 && "Can't load this register from stack slot");
251 BuildMI(MBB, I, get(Opc), DestReg).addImm(0).addFrameIndex(FI);
254 void MipsInstrInfo::loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
255 SmallVectorImpl<MachineOperand> &Addr,
256 const TargetRegisterClass *RC,
257 SmallVectorImpl<MachineInstr*> &NewMIs) const {
259 if (RC == Mips::CPURegsRegisterClass)
261 else if (RC == Mips::FGR32RegisterClass)
263 else if (RC == Mips::AFGR32RegisterClass)
265 else if (RC == Mips::AFGR64RegisterClass)
268 assert(0 && "Can't load this register");
270 MachineInstrBuilder MIB = BuildMI(MF, get(Opc), DestReg);
271 for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
272 MachineOperand &MO = Addr[i];
274 MIB.addReg(MO.getReg());
276 MIB.addImm(MO.getImm());
278 MIB.addFrameIndex(MO.getIndex());
280 NewMIs.push_back(MIB);
284 MachineInstr *MipsInstrInfo::
285 foldMemoryOperandImpl(MachineFunction &MF,
287 const SmallVectorImpl<unsigned> &Ops, int FI) const
289 if (Ops.size() != 1) return NULL;
291 MachineInstr *NewMI = NULL;
293 switch (MI->getOpcode()) {
295 if ((MI->getOperand(0).isReg()) &&
296 (MI->getOperand(1).isReg()) &&
297 (MI->getOperand(1).getReg() == Mips::ZERO) &&
298 (MI->getOperand(2).isReg())) {
299 if (Ops[0] == 0) { // COPY -> STORE
300 unsigned SrcReg = MI->getOperand(2).getReg();
301 bool isKill = MI->getOperand(2).isKill();
302 NewMI = BuildMI(MF, get(Mips::SW)).addReg(SrcReg, false, false, isKill)
303 .addImm(0).addFrameIndex(FI);
304 } else { // COPY -> LOAD
305 unsigned DstReg = MI->getOperand(0).getReg();
306 bool isDead = MI->getOperand(0).isDead();
307 NewMI = BuildMI(MF, get(Mips::LW))
308 .addReg(DstReg, true, false, false, isDead)
309 .addImm(0).addFrameIndex(FI);
313 case Mips::FMOV_SO32:
314 case Mips::FMOV_AS32:
316 if ((MI->getOperand(0).isReg()) &&
317 (MI->getOperand(1).isReg())) {
318 const TargetRegisterClass
319 *RC = RI.getRegClass(MI->getOperand(0).getReg());
320 unsigned StoreOpc, LoadOpc;
322 if (RC == Mips::FGR32RegisterClass) {
323 LoadOpc = Mips::LWC1; StoreOpc = Mips::SWC1;
324 } else if (RC == Mips::AFGR32RegisterClass) {
325 LoadOpc = Mips::LWC1A; StoreOpc = Mips::SWC1A;
326 } else if (RC == Mips::AFGR64RegisterClass) {
327 LoadOpc = Mips::LDC1; StoreOpc = Mips::SDC1;
329 assert(0 && "foldMemoryOperandImpl register unknown");
331 if (Ops[0] == 0) { // COPY -> STORE
332 unsigned SrcReg = MI->getOperand(1).getReg();
333 bool isKill = MI->getOperand(1).isKill();
334 NewMI = BuildMI(MF, get(StoreOpc)).addReg(SrcReg, false, false, isKill)
335 .addImm(0).addFrameIndex(FI) ;
336 } else { // COPY -> LOAD
337 unsigned DstReg = MI->getOperand(0).getReg();
338 bool isDead = MI->getOperand(0).isDead();
339 NewMI = BuildMI(MF, get(LoadOpc))
340 .addReg(DstReg, true, false, false, isDead)
341 .addImm(0).addFrameIndex(FI);
350 //===----------------------------------------------------------------------===//
352 //===----------------------------------------------------------------------===//
354 /// GetCondFromBranchOpc - Return the Mips CC that matches
355 /// the correspondent Branch instruction opcode.
356 static Mips::CondCode GetCondFromBranchOpc(unsigned BrOpc)
359 default: return Mips::COND_INVALID;
360 case Mips::BEQ : return Mips::COND_E;
361 case Mips::BNE : return Mips::COND_NE;
362 case Mips::BGTZ : return Mips::COND_GZ;
363 case Mips::BGEZ : return Mips::COND_GEZ;
364 case Mips::BLTZ : return Mips::COND_LZ;
365 case Mips::BLEZ : return Mips::COND_LEZ;
367 // We dont do fp branch analysis yet!
369 case Mips::BC1F : return Mips::COND_INVALID;
373 /// GetCondBranchFromCond - Return the Branch instruction
374 /// opcode that matches the cc.
375 unsigned Mips::GetCondBranchFromCond(Mips::CondCode CC)
378 default: assert(0 && "Illegal condition code!");
379 case Mips::COND_E : return Mips::BEQ;
380 case Mips::COND_NE : return Mips::BNE;
381 case Mips::COND_GZ : return Mips::BGTZ;
382 case Mips::COND_GEZ : return Mips::BGEZ;
383 case Mips::COND_LZ : return Mips::BLTZ;
384 case Mips::COND_LEZ : return Mips::BLEZ;
389 case Mips::FCOND_UEQ:
390 case Mips::FCOND_OLT:
391 case Mips::FCOND_ULT:
392 case Mips::FCOND_OLE:
393 case Mips::FCOND_ULE:
395 case Mips::FCOND_NGLE:
396 case Mips::FCOND_SEQ:
397 case Mips::FCOND_NGL:
399 case Mips::FCOND_NGE:
401 case Mips::FCOND_NGT: return Mips::BC1T;
405 case Mips::FCOND_NEQ:
406 case Mips::FCOND_OGL:
407 case Mips::FCOND_UGE:
408 case Mips::FCOND_OGE:
409 case Mips::FCOND_UGT:
410 case Mips::FCOND_OGT:
412 case Mips::FCOND_GLE:
413 case Mips::FCOND_SNE:
415 case Mips::FCOND_NLT:
417 case Mips::FCOND_NLE:
418 case Mips::FCOND_GT: return Mips::BC1F;
422 /// GetOppositeBranchCondition - Return the inverse of the specified
423 /// condition, e.g. turning COND_E to COND_NE.
424 Mips::CondCode Mips::GetOppositeBranchCondition(Mips::CondCode CC)
427 default: assert(0 && "Illegal condition code!");
428 case Mips::COND_E : return Mips::COND_NE;
429 case Mips::COND_NE : return Mips::COND_E;
430 case Mips::COND_GZ : return Mips::COND_LEZ;
431 case Mips::COND_GEZ : return Mips::COND_LZ;
432 case Mips::COND_LZ : return Mips::COND_GEZ;
433 case Mips::COND_LEZ : return Mips::COND_GZ;
434 case Mips::FCOND_F : return Mips::FCOND_T;
435 case Mips::FCOND_UN : return Mips::FCOND_OR;
436 case Mips::FCOND_EQ : return Mips::FCOND_NEQ;
437 case Mips::FCOND_UEQ: return Mips::FCOND_OGL;
438 case Mips::FCOND_OLT: return Mips::FCOND_UGE;
439 case Mips::FCOND_ULT: return Mips::FCOND_OGE;
440 case Mips::FCOND_OLE: return Mips::FCOND_UGT;
441 case Mips::FCOND_ULE: return Mips::FCOND_OGT;
442 case Mips::FCOND_SF: return Mips::FCOND_ST;
443 case Mips::FCOND_NGLE:return Mips::FCOND_GLE;
444 case Mips::FCOND_SEQ: return Mips::FCOND_SNE;
445 case Mips::FCOND_NGL: return Mips::FCOND_GL;
446 case Mips::FCOND_LT: return Mips::FCOND_NLT;
447 case Mips::FCOND_NGE: return Mips::FCOND_GE;
448 case Mips::FCOND_LE: return Mips::FCOND_NLE;
449 case Mips::FCOND_NGT: return Mips::FCOND_GT;
453 bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
454 MachineBasicBlock *&TBB,
455 MachineBasicBlock *&FBB,
456 SmallVectorImpl<MachineOperand> &Cond) const
458 // If the block has no terminators, it just falls into the block after it.
459 MachineBasicBlock::iterator I = MBB.end();
460 if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
463 // Get the last instruction in the block.
464 MachineInstr *LastInst = I;
466 // If there is only one terminator instruction, process it.
467 unsigned LastOpc = LastInst->getOpcode();
468 if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
469 if (!LastInst->getDesc().isBranch())
472 // Unconditional branch
473 if (LastOpc == Mips::J) {
474 TBB = LastInst->getOperand(0).getMBB();
478 Mips::CondCode BranchCode = GetCondFromBranchOpc(LastInst->getOpcode());
479 if (BranchCode == Mips::COND_INVALID)
480 return true; // Can't handle indirect branch.
482 // Conditional branch
483 // Block ends with fall-through condbranch.
484 if (LastOpc != Mips::COND_INVALID) {
485 int LastNumOp = LastInst->getNumOperands();
487 TBB = LastInst->getOperand(LastNumOp-1).getMBB();
488 Cond.push_back(MachineOperand::CreateImm(BranchCode));
490 for (int i=0; i<LastNumOp-1; i++) {
491 Cond.push_back(LastInst->getOperand(i));
498 // Get the instruction before it if it is a terminator.
499 MachineInstr *SecondLastInst = I;
501 // If there are three terminators, we don't know what sort of block this is.
502 if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(--I))
505 // If the block ends with Mips::J and a Mips::BNE/Mips::BEQ, handle it.
506 unsigned SecondLastOpc = SecondLastInst->getOpcode();
507 Mips::CondCode BranchCode = GetCondFromBranchOpc(SecondLastOpc);
509 if (BranchCode != Mips::COND_INVALID && LastOpc == Mips::J) {
510 int SecondNumOp = SecondLastInst->getNumOperands();
512 TBB = SecondLastInst->getOperand(SecondNumOp-1).getMBB();
513 Cond.push_back(MachineOperand::CreateImm(BranchCode));
515 for (int i=0; i<SecondNumOp-1; i++) {
516 Cond.push_back(SecondLastInst->getOperand(i));
519 FBB = LastInst->getOperand(0).getMBB();
523 // If the block ends with two unconditional branches, handle it. The last
524 // one is not executed, so remove it.
525 if ((SecondLastOpc == Mips::J) && (LastOpc == Mips::J)) {
526 TBB = SecondLastInst->getOperand(0).getMBB();
528 I->eraseFromParent();
532 // Otherwise, can't handle this.
536 unsigned MipsInstrInfo::
537 InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
538 MachineBasicBlock *FBB,
539 const SmallVectorImpl<MachineOperand> &Cond) const {
540 // Shouldn't be a fall through.
541 assert(TBB && "InsertBranch must not be told to insert a fallthrough");
542 assert((Cond.size() == 3 || Cond.size() == 2 || Cond.size() == 0) &&
543 "Mips branch conditions can have two|three components!");
545 if (FBB == 0) { // One way branch.
547 // Unconditional branch?
548 BuildMI(&MBB, get(Mips::J)).addMBB(TBB);
550 // Conditional branch.
551 unsigned Opc = GetCondBranchFromCond((Mips::CondCode)Cond[0].getImm());
552 const TargetInstrDesc &TID = get(Opc);
554 if (TID.getNumOperands() == 3)
555 BuildMI(&MBB, TID).addReg(Cond[1].getReg())
556 .addReg(Cond[2].getReg())
559 BuildMI(&MBB, TID).addReg(Cond[1].getReg())
566 // Two-way Conditional branch.
567 unsigned Opc = GetCondBranchFromCond((Mips::CondCode)Cond[0].getImm());
568 const TargetInstrDesc &TID = get(Opc);
570 if (TID.getNumOperands() == 3)
571 BuildMI(&MBB, TID).addReg(Cond[1].getReg()).addReg(Cond[2].getReg())
574 BuildMI(&MBB, TID).addReg(Cond[1].getReg()).addMBB(TBB);
576 BuildMI(&MBB, get(Mips::J)).addMBB(FBB);
580 unsigned MipsInstrInfo::
581 RemoveBranch(MachineBasicBlock &MBB) const
583 MachineBasicBlock::iterator I = MBB.end();
584 if (I == MBB.begin()) return 0;
586 if (I->getOpcode() != Mips::J &&
587 GetCondFromBranchOpc(I->getOpcode()) == Mips::COND_INVALID)
590 // Remove the branch.
591 I->eraseFromParent();
595 if (I == MBB.begin()) return 1;
597 if (GetCondFromBranchOpc(I->getOpcode()) == Mips::COND_INVALID)
600 // Remove the branch.
601 I->eraseFromParent();
605 /// BlockHasNoFallThrough - Analyze if MachineBasicBlock does not
606 /// fall-through into its successor block.
608 BlockHasNoFallThrough(const MachineBasicBlock &MBB) const
610 if (MBB.empty()) return false;
612 switch (MBB.back().getOpcode()) {
613 case Mips::RET: // Return.
614 case Mips::JR: // Indirect branch.
615 case Mips::J: // Uncond branch.
617 default: return false;
621 /// ReverseBranchCondition - Return the inverse opcode of the
622 /// specified Branch instruction.
624 ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
626 assert( (Cond.size() == 3 || Cond.size() == 2) &&
627 "Invalid Mips branch condition!");
628 Cond[0].setImm(GetOppositeBranchCondition((Mips::CondCode)Cond[0].getImm()));