1 //===-- SystemZInstrInfo.cpp - SystemZ instruction information ------------===//
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 SystemZ implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "SystemZInstrInfo.h"
15 #include "SystemZTargetMachine.h"
16 #include "SystemZInstrBuilder.h"
17 #include "llvm/CodeGen/LiveVariables.h"
18 #include "llvm/CodeGen/MachineRegisterInfo.h"
20 #define GET_INSTRINFO_CTOR
21 #define GET_INSTRMAP_INFO
22 #include "SystemZGenInstrInfo.inc"
26 SystemZInstrInfo::SystemZInstrInfo(SystemZTargetMachine &tm)
27 : SystemZGenInstrInfo(SystemZ::ADJCALLSTACKDOWN, SystemZ::ADJCALLSTACKUP),
31 // MI is a 128-bit load or store. Split it into two 64-bit loads or stores,
32 // each having the opcode given by NewOpcode.
33 void SystemZInstrInfo::splitMove(MachineBasicBlock::iterator MI,
34 unsigned NewOpcode) const {
35 MachineBasicBlock *MBB = MI->getParent();
36 MachineFunction &MF = *MBB->getParent();
38 // Get two load or store instructions. Use the original instruction for one
39 // of them (arbitarily the second here) and create a clone for the other.
40 MachineInstr *EarlierMI = MF.CloneMachineInstr(MI);
41 MBB->insert(MI, EarlierMI);
43 // Set up the two 64-bit registers.
44 MachineOperand &HighRegOp = EarlierMI->getOperand(0);
45 MachineOperand &LowRegOp = MI->getOperand(0);
46 HighRegOp.setReg(RI.getSubReg(HighRegOp.getReg(), SystemZ::subreg_high));
47 LowRegOp.setReg(RI.getSubReg(LowRegOp.getReg(), SystemZ::subreg_low));
49 // The address in the first (high) instruction is already correct.
50 // Adjust the offset in the second (low) instruction.
51 MachineOperand &HighOffsetOp = EarlierMI->getOperand(2);
52 MachineOperand &LowOffsetOp = MI->getOperand(2);
53 LowOffsetOp.setImm(LowOffsetOp.getImm() + 8);
56 unsigned HighOpcode = getOpcodeForOffset(NewOpcode, HighOffsetOp.getImm());
57 unsigned LowOpcode = getOpcodeForOffset(NewOpcode, LowOffsetOp.getImm());
58 assert(HighOpcode && LowOpcode && "Both offsets should be in range");
60 EarlierMI->setDesc(get(HighOpcode));
61 MI->setDesc(get(LowOpcode));
64 // Split ADJDYNALLOC instruction MI.
65 void SystemZInstrInfo::splitAdjDynAlloc(MachineBasicBlock::iterator MI) const {
66 MachineBasicBlock *MBB = MI->getParent();
67 MachineFunction &MF = *MBB->getParent();
68 MachineFrameInfo *MFFrame = MF.getFrameInfo();
69 MachineOperand &OffsetMO = MI->getOperand(2);
71 uint64_t Offset = (MFFrame->getMaxCallFrameSize() +
72 SystemZMC::CallFrameSize +
74 unsigned NewOpcode = getOpcodeForOffset(SystemZ::LA, Offset);
75 assert(NewOpcode && "No support for huge argument lists yet");
76 MI->setDesc(get(NewOpcode));
77 OffsetMO.setImm(Offset);
80 // If MI is a simple load or store for a frame object, return the register
81 // it loads or stores and set FrameIndex to the index of the frame object.
82 // Return 0 otherwise.
84 // Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores.
85 static int isSimpleMove(const MachineInstr *MI, int &FrameIndex,
87 const MCInstrDesc &MCID = MI->getDesc();
88 if ((MCID.TSFlags & Flag) &&
89 MI->getOperand(1).isFI() &&
90 MI->getOperand(2).getImm() == 0 &&
91 MI->getOperand(3).getReg() == 0) {
92 FrameIndex = MI->getOperand(1).getIndex();
93 return MI->getOperand(0).getReg();
98 unsigned SystemZInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
99 int &FrameIndex) const {
100 return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXLoad);
103 unsigned SystemZInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
104 int &FrameIndex) const {
105 return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXStore);
108 bool SystemZInstrInfo::isStackSlotCopy(const MachineInstr *MI,
110 int &SrcFrameIndex) const {
111 // Check for MVC 0(Length,FI1),0(FI2)
112 const MachineFrameInfo *MFI = MI->getParent()->getParent()->getFrameInfo();
113 if (MI->getOpcode() != SystemZ::MVC ||
114 !MI->getOperand(0).isFI() ||
115 MI->getOperand(1).getImm() != 0 ||
116 !MI->getOperand(3).isFI() ||
117 MI->getOperand(4).getImm() != 0)
120 // Check that Length covers the full slots.
121 int64_t Length = MI->getOperand(2).getImm();
122 unsigned FI1 = MI->getOperand(0).getIndex();
123 unsigned FI2 = MI->getOperand(3).getIndex();
124 if (MFI->getObjectSize(FI1) != Length ||
125 MFI->getObjectSize(FI2) != Length)
128 DestFrameIndex = FI1;
133 bool SystemZInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
134 MachineBasicBlock *&TBB,
135 MachineBasicBlock *&FBB,
136 SmallVectorImpl<MachineOperand> &Cond,
137 bool AllowModify) const {
138 // Most of the code and comments here are boilerplate.
140 // Start from the bottom of the block and work up, examining the
141 // terminator instructions.
142 MachineBasicBlock::iterator I = MBB.end();
143 while (I != MBB.begin()) {
145 if (I->isDebugValue())
148 // Working from the bottom, when we see a non-terminator instruction, we're
150 if (!isUnpredicatedTerminator(I))
153 // A terminator that isn't a branch can't easily be handled by this
158 // Can't handle indirect branches.
159 SystemZII::Branch Branch(getBranchInfo(I));
160 if (!Branch.Target->isMBB())
163 // Punt on compound branches.
164 if (Branch.Type != SystemZII::BranchNormal)
167 if (Branch.CCMask == SystemZ::CCMASK_ANY) {
168 // Handle unconditional branches.
170 TBB = Branch.Target->getMBB();
174 // If the block has any instructions after a JMP, delete them.
175 while (llvm::next(I) != MBB.end())
176 llvm::next(I)->eraseFromParent();
181 // Delete the JMP if it's equivalent to a fall-through.
182 if (MBB.isLayoutSuccessor(Branch.Target->getMBB())) {
184 I->eraseFromParent();
189 // TBB is used to indicate the unconditinal destination.
190 TBB = Branch.Target->getMBB();
194 // Working from the bottom, handle the first conditional branch.
196 // FIXME: add X86-style branch swap
198 TBB = Branch.Target->getMBB();
199 Cond.push_back(MachineOperand::CreateImm(Branch.CCMask));
203 // Handle subsequent conditional branches.
204 assert(Cond.size() == 1);
207 // Only handle the case where all conditional branches branch to the same
209 if (TBB != Branch.Target->getMBB())
212 // If the conditions are the same, we can leave them alone.
213 unsigned OldCond = Cond[0].getImm();
214 if (OldCond == Branch.CCMask)
217 // FIXME: Try combining conditions like X86 does. Should be easy on Z!
223 unsigned SystemZInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
224 // Most of the code and comments here are boilerplate.
225 MachineBasicBlock::iterator I = MBB.end();
228 while (I != MBB.begin()) {
230 if (I->isDebugValue())
234 if (!getBranchInfo(I).Target->isMBB())
236 // Remove the branch.
237 I->eraseFromParent();
246 SystemZInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
247 MachineBasicBlock *FBB,
248 const SmallVectorImpl<MachineOperand> &Cond,
250 // In this function we output 32-bit branches, which should always
251 // have enough range. They can be shortened and relaxed by later code
252 // in the pipeline, if desired.
254 // Shouldn't be a fall through.
255 assert(TBB && "InsertBranch must not be told to insert a fallthrough");
256 assert((Cond.size() == 1 || Cond.size() == 0) &&
257 "SystemZ branch conditions have one component!");
260 // Unconditional branch?
261 assert(!FBB && "Unconditional branch with multiple successors!");
262 BuildMI(&MBB, DL, get(SystemZ::J)).addMBB(TBB);
266 // Conditional branch.
268 unsigned CC = Cond[0].getImm();
269 BuildMI(&MBB, DL, get(SystemZ::BRC)).addImm(CC).addMBB(TBB);
273 // Two-way Conditional branch. Insert the second branch.
274 BuildMI(&MBB, DL, get(SystemZ::J)).addMBB(FBB);
281 SystemZInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
282 MachineBasicBlock::iterator MBBI, DebugLoc DL,
283 unsigned DestReg, unsigned SrcReg,
284 bool KillSrc) const {
285 // Split 128-bit GPR moves into two 64-bit moves. This handles ADDR128 too.
286 if (SystemZ::GR128BitRegClass.contains(DestReg, SrcReg)) {
287 copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_high),
288 RI.getSubReg(SrcReg, SystemZ::subreg_high), KillSrc);
289 copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_low),
290 RI.getSubReg(SrcReg, SystemZ::subreg_low), KillSrc);
294 // Everything else needs only one instruction.
296 if (SystemZ::GR32BitRegClass.contains(DestReg, SrcReg))
297 Opcode = SystemZ::LR;
298 else if (SystemZ::GR64BitRegClass.contains(DestReg, SrcReg))
299 Opcode = SystemZ::LGR;
300 else if (SystemZ::FP32BitRegClass.contains(DestReg, SrcReg))
301 Opcode = SystemZ::LER;
302 else if (SystemZ::FP64BitRegClass.contains(DestReg, SrcReg))
303 Opcode = SystemZ::LDR;
304 else if (SystemZ::FP128BitRegClass.contains(DestReg, SrcReg))
305 Opcode = SystemZ::LXR;
307 llvm_unreachable("Impossible reg-to-reg copy");
309 BuildMI(MBB, MBBI, DL, get(Opcode), DestReg)
310 .addReg(SrcReg, getKillRegState(KillSrc));
314 SystemZInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
315 MachineBasicBlock::iterator MBBI,
316 unsigned SrcReg, bool isKill,
318 const TargetRegisterClass *RC,
319 const TargetRegisterInfo *TRI) const {
320 DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
322 // Callers may expect a single instruction, so keep 128-bit moves
323 // together for now and lower them after register allocation.
324 unsigned LoadOpcode, StoreOpcode;
325 getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode);
326 addFrameReference(BuildMI(MBB, MBBI, DL, get(StoreOpcode))
327 .addReg(SrcReg, getKillRegState(isKill)), FrameIdx);
331 SystemZInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
332 MachineBasicBlock::iterator MBBI,
333 unsigned DestReg, int FrameIdx,
334 const TargetRegisterClass *RC,
335 const TargetRegisterInfo *TRI) const {
336 DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
338 // Callers may expect a single instruction, so keep 128-bit moves
339 // together for now and lower them after register allocation.
340 unsigned LoadOpcode, StoreOpcode;
341 getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode);
342 addFrameReference(BuildMI(MBB, MBBI, DL, get(LoadOpcode), DestReg),
346 // Return true if MI is a simple load or store with a 12-bit displacement
347 // and no index. Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores.
348 static bool isSimpleBD12Move(const MachineInstr *MI, unsigned Flag) {
349 const MCInstrDesc &MCID = MI->getDesc();
350 return ((MCID.TSFlags & Flag) &&
351 isUInt<12>(MI->getOperand(2).getImm()) &&
352 MI->getOperand(3).getReg() == 0);
356 SystemZInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
357 MachineBasicBlock::iterator &MBBI,
358 LiveVariables *LV) const {
359 MachineInstr *MI = MBBI;
360 MachineBasicBlock *MBB = MI->getParent();
362 unsigned Opcode = MI->getOpcode();
363 unsigned NumOps = MI->getNumOperands();
365 // Try to convert something like SLL into SLLK, if supported.
366 // We prefer to keep the two-operand form where possible both
367 // because it tends to be shorter and because some instructions
368 // have memory forms that can be used during spilling.
369 if (TM.getSubtargetImpl()->hasDistinctOps()) {
370 int ThreeOperandOpcode = SystemZ::getThreeOperandOpcode(Opcode);
371 if (ThreeOperandOpcode >= 0) {
372 unsigned DestReg = MI->getOperand(0).getReg();
373 MachineOperand &Src = MI->getOperand(1);
374 MachineInstrBuilder MIB = BuildMI(*MBB, MBBI, MI->getDebugLoc(),
375 get(ThreeOperandOpcode), DestReg);
376 // Keep the kill state, but drop the tied flag.
377 MIB.addReg(Src.getReg(), getKillRegState(Src.isKill()));
378 // Keep the remaining operands as-is.
379 for (unsigned I = 2; I < NumOps; ++I)
380 MIB.addOperand(MI->getOperand(I));
381 MachineInstr *NewMI = MIB;
383 // Transfer killing information to the new instruction.
385 for (unsigned I = 1; I < NumOps; ++I) {
386 MachineOperand &Op = MI->getOperand(I);
387 if (Op.isReg() && Op.isKill())
388 LV->replaceKillInstruction(Op.getReg(), MI, NewMI);
398 SystemZInstrInfo::foldMemoryOperandImpl(MachineFunction &MF,
400 const SmallVectorImpl<unsigned> &Ops,
401 int FrameIndex) const {
402 const MachineFrameInfo *MFI = MF.getFrameInfo();
403 unsigned Size = MFI->getObjectSize(FrameIndex);
405 // Eary exit for cases we don't care about
409 unsigned OpNum = Ops[0];
410 assert(Size == MF.getRegInfo()
411 .getRegClass(MI->getOperand(OpNum).getReg())->getSize() &&
412 "Invalid size combination");
414 unsigned Opcode = MI->getOpcode();
415 if (Opcode == SystemZ::LGDR || Opcode == SystemZ::LDGR) {
416 bool Op0IsGPR = (Opcode == SystemZ::LGDR);
417 bool Op1IsGPR = (Opcode == SystemZ::LDGR);
418 // If we're spilling the destination of an LDGR or LGDR, store the
419 // source register instead.
421 unsigned StoreOpcode = Op1IsGPR ? SystemZ::STG : SystemZ::STD;
422 return BuildMI(MF, MI->getDebugLoc(), get(StoreOpcode))
423 .addOperand(MI->getOperand(1)).addFrameIndex(FrameIndex)
424 .addImm(0).addReg(0);
426 // If we're spilling the source of an LDGR or LGDR, load the
427 // destination register instead.
429 unsigned LoadOpcode = Op0IsGPR ? SystemZ::LG : SystemZ::LD;
430 unsigned Dest = MI->getOperand(0).getReg();
431 return BuildMI(MF, MI->getDebugLoc(), get(LoadOpcode), Dest)
432 .addFrameIndex(FrameIndex).addImm(0).addReg(0);
436 // Look for cases where the source of a simple store or the destination
437 // of a simple load is being spilled. Try to use MVC instead.
439 // Although MVC is in practice a fast choice in these cases, it is still
440 // logically a bytewise copy. This means that we cannot use it if the
441 // load or store is volatile. It also means that the transformation is
442 // not valid in cases where the two memories partially overlap; however,
443 // that is not a problem here, because we know that one of the memories
444 // is a full frame index.
445 if (OpNum == 0 && MI->hasOneMemOperand()) {
446 MachineMemOperand *MMO = *MI->memoperands_begin();
447 if (MMO->getSize() == Size && !MMO->isVolatile()) {
448 // Handle conversion of loads.
449 if (isSimpleBD12Move(MI, SystemZII::SimpleBDXLoad)) {
450 return BuildMI(MF, MI->getDebugLoc(), get(SystemZ::MVC))
451 .addFrameIndex(FrameIndex).addImm(0).addImm(Size)
452 .addOperand(MI->getOperand(1)).addImm(MI->getOperand(2).getImm())
455 // Handle conversion of stores.
456 if (isSimpleBD12Move(MI, SystemZII::SimpleBDXStore)) {
457 return BuildMI(MF, MI->getDebugLoc(), get(SystemZ::MVC))
458 .addOperand(MI->getOperand(1)).addImm(MI->getOperand(2).getImm())
459 .addImm(Size).addFrameIndex(FrameIndex).addImm(0)
465 // If the spilled operand is the final one, try to change <INSN>R
467 int MemOpcode = SystemZ::getMemOpcode(Opcode);
468 if (MemOpcode >= 0) {
469 unsigned NumOps = MI->getNumExplicitOperands();
470 if (OpNum == NumOps - 1) {
471 const MCInstrDesc &MemDesc = get(MemOpcode);
472 uint64_t AccessBytes = SystemZII::getAccessSize(MemDesc.TSFlags);
473 assert(AccessBytes != 0 && "Size of access should be known");
474 assert(AccessBytes <= Size && "Access outside the frame index");
475 uint64_t Offset = Size - AccessBytes;
476 MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), get(MemOpcode));
477 for (unsigned I = 0; I < OpNum; ++I)
478 MIB.addOperand(MI->getOperand(I));
479 MIB.addFrameIndex(FrameIndex).addImm(Offset);
480 if (MemDesc.TSFlags & SystemZII::HasIndex)
490 SystemZInstrInfo::foldMemoryOperandImpl(MachineFunction &MF, MachineInstr* MI,
491 const SmallVectorImpl<unsigned> &Ops,
492 MachineInstr* LoadMI) const {
497 SystemZInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const {
498 switch (MI->getOpcode()) {
500 splitMove(MI, SystemZ::LG);
504 splitMove(MI, SystemZ::STG);
508 splitMove(MI, SystemZ::LD);
512 splitMove(MI, SystemZ::STD);
515 case SystemZ::ADJDYNALLOC:
516 splitAdjDynAlloc(MI);
524 bool SystemZInstrInfo::
525 ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
526 assert(Cond.size() == 1 && "Invalid branch condition!");
527 Cond[0].setImm(Cond[0].getImm() ^ SystemZ::CCMASK_ANY);
531 uint64_t SystemZInstrInfo::getInstSizeInBytes(const MachineInstr *MI) const {
532 if (MI->getOpcode() == TargetOpcode::INLINEASM) {
533 const MachineFunction *MF = MI->getParent()->getParent();
534 const char *AsmStr = MI->getOperand(0).getSymbolName();
535 return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
537 return MI->getDesc().getSize();
541 SystemZInstrInfo::getBranchInfo(const MachineInstr *MI) const {
542 switch (MI->getOpcode()) {
546 return SystemZII::Branch(SystemZII::BranchNormal, SystemZ::CCMASK_ANY,
551 return SystemZII::Branch(SystemZII::BranchNormal,
552 MI->getOperand(0).getImm(), &MI->getOperand(1));
556 return SystemZII::Branch(SystemZII::BranchC, MI->getOperand(2).getImm(),
561 return SystemZII::Branch(SystemZII::BranchCG, MI->getOperand(2).getImm(),
565 llvm_unreachable("Unrecognized branch opcode");
569 void SystemZInstrInfo::getLoadStoreOpcodes(const TargetRegisterClass *RC,
570 unsigned &LoadOpcode,
571 unsigned &StoreOpcode) const {
572 if (RC == &SystemZ::GR32BitRegClass || RC == &SystemZ::ADDR32BitRegClass) {
573 LoadOpcode = SystemZ::L;
574 StoreOpcode = SystemZ::ST32;
575 } else if (RC == &SystemZ::GR64BitRegClass ||
576 RC == &SystemZ::ADDR64BitRegClass) {
577 LoadOpcode = SystemZ::LG;
578 StoreOpcode = SystemZ::STG;
579 } else if (RC == &SystemZ::GR128BitRegClass ||
580 RC == &SystemZ::ADDR128BitRegClass) {
581 LoadOpcode = SystemZ::L128;
582 StoreOpcode = SystemZ::ST128;
583 } else if (RC == &SystemZ::FP32BitRegClass) {
584 LoadOpcode = SystemZ::LE;
585 StoreOpcode = SystemZ::STE;
586 } else if (RC == &SystemZ::FP64BitRegClass) {
587 LoadOpcode = SystemZ::LD;
588 StoreOpcode = SystemZ::STD;
589 } else if (RC == &SystemZ::FP128BitRegClass) {
590 LoadOpcode = SystemZ::LX;
591 StoreOpcode = SystemZ::STX;
593 llvm_unreachable("Unsupported regclass to load or store");
596 unsigned SystemZInstrInfo::getOpcodeForOffset(unsigned Opcode,
597 int64_t Offset) const {
598 const MCInstrDesc &MCID = get(Opcode);
599 int64_t Offset2 = (MCID.TSFlags & SystemZII::Is128Bit ? Offset + 8 : Offset);
600 if (isUInt<12>(Offset) && isUInt<12>(Offset2)) {
601 // Get the instruction to use for unsigned 12-bit displacements.
602 int Disp12Opcode = SystemZ::getDisp12Opcode(Opcode);
603 if (Disp12Opcode >= 0)
606 // All address-related instructions can use unsigned 12-bit
610 if (isInt<20>(Offset) && isInt<20>(Offset2)) {
611 // Get the instruction to use for signed 20-bit displacements.
612 int Disp20Opcode = SystemZ::getDisp20Opcode(Opcode);
613 if (Disp20Opcode >= 0)
616 // Check whether Opcode allows signed 20-bit displacements.
617 if (MCID.TSFlags & SystemZII::Has20BitOffset)
623 unsigned SystemZInstrInfo::getCompareAndBranch(unsigned Opcode,
624 const MachineInstr *MI) const {
629 return SystemZ::CGRJ;
631 return MI && isInt<8>(MI->getOperand(1).getImm()) ? SystemZ::CIJ : 0;
633 return MI && isInt<8>(MI->getOperand(1).getImm()) ? SystemZ::CGIJ : 0;
639 void SystemZInstrInfo::loadImmediate(MachineBasicBlock &MBB,
640 MachineBasicBlock::iterator MBBI,
641 unsigned Reg, uint64_t Value) const {
642 DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
644 if (isInt<16>(Value))
645 Opcode = SystemZ::LGHI;
646 else if (SystemZ::isImmLL(Value))
647 Opcode = SystemZ::LLILL;
648 else if (SystemZ::isImmLH(Value)) {
649 Opcode = SystemZ::LLILH;
652 assert(isInt<32>(Value) && "Huge values not handled yet");
653 Opcode = SystemZ::LGFI;
655 BuildMI(MBB, MBBI, DL, get(Opcode), Reg).addImm(Value);