xref: /freebsd/contrib/llvm-project/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp (revision 47ef2a131091508e049ab10cad7f91a3c1342cd9)
1 //===-- SystemZInstrInfo.cpp - SystemZ instruction information ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains the SystemZ implementation of the TargetInstrInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "SystemZInstrInfo.h"
14 #include "MCTargetDesc/SystemZMCTargetDesc.h"
15 #include "SystemZ.h"
16 #include "SystemZInstrBuilder.h"
17 #include "SystemZSubtarget.h"
18 #include "llvm/ADT/Statistic.h"
19 #include "llvm/CodeGen/LiveInterval.h"
20 #include "llvm/CodeGen/LiveIntervals.h"
21 #include "llvm/CodeGen/LiveRegUnits.h"
22 #include "llvm/CodeGen/LiveVariables.h"
23 #include "llvm/CodeGen/MachineBasicBlock.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/MachineMemOperand.h"
28 #include "llvm/CodeGen/MachineOperand.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/CodeGen/SlotIndexes.h"
31 #include "llvm/CodeGen/StackMaps.h"
32 #include "llvm/CodeGen/TargetInstrInfo.h"
33 #include "llvm/CodeGen/TargetSubtargetInfo.h"
34 #include "llvm/CodeGen/VirtRegMap.h"
35 #include "llvm/MC/MCInstrDesc.h"
36 #include "llvm/MC/MCRegisterInfo.h"
37 #include "llvm/Support/BranchProbability.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/MathExtras.h"
40 #include "llvm/Target/TargetMachine.h"
41 #include <cassert>
42 #include <cstdint>
43 #include <iterator>
44 
45 using namespace llvm;
46 
47 #define GET_INSTRINFO_CTOR_DTOR
48 #define GET_INSTRMAP_INFO
49 #include "SystemZGenInstrInfo.inc"
50 
51 #define DEBUG_TYPE "systemz-II"
52 
53 // Return a mask with Count low bits set.
54 static uint64_t allOnes(unsigned int Count) {
55   return Count == 0 ? 0 : (uint64_t(1) << (Count - 1) << 1) - 1;
56 }
57 
58 // Pin the vtable to this file.
59 void SystemZInstrInfo::anchor() {}
60 
61 SystemZInstrInfo::SystemZInstrInfo(SystemZSubtarget &sti)
62     : SystemZGenInstrInfo(-1, -1),
63       RI(sti.getSpecialRegisters()->getReturnFunctionAddressRegister()),
64       STI(sti) {}
65 
66 // MI is a 128-bit load or store.  Split it into two 64-bit loads or stores,
67 // each having the opcode given by NewOpcode.
68 void SystemZInstrInfo::splitMove(MachineBasicBlock::iterator MI,
69                                  unsigned NewOpcode) const {
70   MachineBasicBlock *MBB = MI->getParent();
71   MachineFunction &MF = *MBB->getParent();
72 
73   // Get two load or store instructions.  Use the original instruction for
74   // one of them and create a clone for the other.
75   MachineInstr *HighPartMI = MF.CloneMachineInstr(&*MI);
76   MachineInstr *LowPartMI = &*MI;
77   MBB->insert(LowPartMI, HighPartMI);
78 
79   // Set up the two 64-bit registers and remember super reg and its flags.
80   MachineOperand &HighRegOp = HighPartMI->getOperand(0);
81   MachineOperand &LowRegOp = LowPartMI->getOperand(0);
82   Register Reg128 = LowRegOp.getReg();
83   unsigned Reg128Killed = getKillRegState(LowRegOp.isKill());
84   unsigned Reg128Undef  = getUndefRegState(LowRegOp.isUndef());
85   HighRegOp.setReg(RI.getSubReg(HighRegOp.getReg(), SystemZ::subreg_h64));
86   LowRegOp.setReg(RI.getSubReg(LowRegOp.getReg(), SystemZ::subreg_l64));
87 
88   // The address in the first (high) instruction is already correct.
89   // Adjust the offset in the second (low) instruction.
90   MachineOperand &HighOffsetOp = HighPartMI->getOperand(2);
91   MachineOperand &LowOffsetOp = LowPartMI->getOperand(2);
92   LowOffsetOp.setImm(LowOffsetOp.getImm() + 8);
93 
94   // Set the opcodes.
95   unsigned HighOpcode = getOpcodeForOffset(NewOpcode, HighOffsetOp.getImm());
96   unsigned LowOpcode = getOpcodeForOffset(NewOpcode, LowOffsetOp.getImm());
97   assert(HighOpcode && LowOpcode && "Both offsets should be in range");
98   HighPartMI->setDesc(get(HighOpcode));
99   LowPartMI->setDesc(get(LowOpcode));
100 
101   MachineInstr *FirstMI = HighPartMI;
102   if (MI->mayStore()) {
103     FirstMI->getOperand(0).setIsKill(false);
104     // Add implicit uses of the super register in case one of the subregs is
105     // undefined. We could track liveness and skip storing an undefined
106     // subreg, but this is hopefully rare (discovered with llvm-stress).
107     // If Reg128 was killed, set kill flag on MI.
108     unsigned Reg128UndefImpl = (Reg128Undef | RegState::Implicit);
109     MachineInstrBuilder(MF, HighPartMI).addReg(Reg128, Reg128UndefImpl);
110     MachineInstrBuilder(MF, LowPartMI).addReg(Reg128, (Reg128UndefImpl | Reg128Killed));
111   } else {
112     // If HighPartMI clobbers any of the address registers, it needs to come
113     // after LowPartMI.
114     auto overlapsAddressReg = [&](Register Reg) -> bool {
115       return RI.regsOverlap(Reg, MI->getOperand(1).getReg()) ||
116              RI.regsOverlap(Reg, MI->getOperand(3).getReg());
117     };
118     if (overlapsAddressReg(HighRegOp.getReg())) {
119       assert(!overlapsAddressReg(LowRegOp.getReg()) &&
120              "Both loads clobber address!");
121       MBB->splice(HighPartMI, MBB, LowPartMI);
122       FirstMI = LowPartMI;
123     }
124   }
125 
126   // Clear the kill flags on the address registers in the first instruction.
127   FirstMI->getOperand(1).setIsKill(false);
128   FirstMI->getOperand(3).setIsKill(false);
129 }
130 
131 // Split ADJDYNALLOC instruction MI.
132 void SystemZInstrInfo::splitAdjDynAlloc(MachineBasicBlock::iterator MI) const {
133   MachineBasicBlock *MBB = MI->getParent();
134   MachineFunction &MF = *MBB->getParent();
135   MachineFrameInfo &MFFrame = MF.getFrameInfo();
136   MachineOperand &OffsetMO = MI->getOperand(2);
137   SystemZCallingConventionRegisters *Regs = STI.getSpecialRegisters();
138 
139   uint64_t Offset = (MFFrame.getMaxCallFrameSize() +
140                      Regs->getCallFrameSize() +
141                      Regs->getStackPointerBias() +
142                      OffsetMO.getImm());
143   unsigned NewOpcode = getOpcodeForOffset(SystemZ::LA, Offset);
144   assert(NewOpcode && "No support for huge argument lists yet");
145   MI->setDesc(get(NewOpcode));
146   OffsetMO.setImm(Offset);
147 }
148 
149 // MI is an RI-style pseudo instruction.  Replace it with LowOpcode
150 // if the first operand is a low GR32 and HighOpcode if the first operand
151 // is a high GR32.  ConvertHigh is true if LowOpcode takes a signed operand
152 // and HighOpcode takes an unsigned 32-bit operand.  In those cases,
153 // MI has the same kind of operand as LowOpcode, so needs to be converted
154 // if HighOpcode is used.
155 void SystemZInstrInfo::expandRIPseudo(MachineInstr &MI, unsigned LowOpcode,
156                                       unsigned HighOpcode,
157                                       bool ConvertHigh) const {
158   Register Reg = MI.getOperand(0).getReg();
159   bool IsHigh = SystemZ::isHighReg(Reg);
160   MI.setDesc(get(IsHigh ? HighOpcode : LowOpcode));
161   if (IsHigh && ConvertHigh)
162     MI.getOperand(1).setImm(uint32_t(MI.getOperand(1).getImm()));
163 }
164 
165 // MI is a three-operand RIE-style pseudo instruction.  Replace it with
166 // LowOpcodeK if the registers are both low GR32s, otherwise use a move
167 // followed by HighOpcode or LowOpcode, depending on whether the target
168 // is a high or low GR32.
169 void SystemZInstrInfo::expandRIEPseudo(MachineInstr &MI, unsigned LowOpcode,
170                                        unsigned LowOpcodeK,
171                                        unsigned HighOpcode) const {
172   Register DestReg = MI.getOperand(0).getReg();
173   Register SrcReg = MI.getOperand(1).getReg();
174   bool DestIsHigh = SystemZ::isHighReg(DestReg);
175   bool SrcIsHigh = SystemZ::isHighReg(SrcReg);
176   if (!DestIsHigh && !SrcIsHigh)
177     MI.setDesc(get(LowOpcodeK));
178   else {
179     if (DestReg != SrcReg) {
180       emitGRX32Move(*MI.getParent(), MI, MI.getDebugLoc(), DestReg, SrcReg,
181                     SystemZ::LR, 32, MI.getOperand(1).isKill(),
182                     MI.getOperand(1).isUndef());
183       MI.getOperand(1).setReg(DestReg);
184     }
185     MI.setDesc(get(DestIsHigh ? HighOpcode : LowOpcode));
186     MI.tieOperands(0, 1);
187   }
188 }
189 
190 // MI is an RXY-style pseudo instruction.  Replace it with LowOpcode
191 // if the first operand is a low GR32 and HighOpcode if the first operand
192 // is a high GR32.
193 void SystemZInstrInfo::expandRXYPseudo(MachineInstr &MI, unsigned LowOpcode,
194                                        unsigned HighOpcode) const {
195   Register Reg = MI.getOperand(0).getReg();
196   unsigned Opcode = getOpcodeForOffset(
197       SystemZ::isHighReg(Reg) ? HighOpcode : LowOpcode,
198       MI.getOperand(2).getImm());
199   MI.setDesc(get(Opcode));
200 }
201 
202 // MI is a load-on-condition pseudo instruction with a single register
203 // (source or destination) operand.  Replace it with LowOpcode if the
204 // register is a low GR32 and HighOpcode if the register is a high GR32.
205 void SystemZInstrInfo::expandLOCPseudo(MachineInstr &MI, unsigned LowOpcode,
206                                        unsigned HighOpcode) const {
207   Register Reg = MI.getOperand(0).getReg();
208   unsigned Opcode = SystemZ::isHighReg(Reg) ? HighOpcode : LowOpcode;
209   MI.setDesc(get(Opcode));
210 }
211 
212 // MI is an RR-style pseudo instruction that zero-extends the low Size bits
213 // of one GRX32 into another.  Replace it with LowOpcode if both operands
214 // are low registers, otherwise use RISB[LH]G.
215 void SystemZInstrInfo::expandZExtPseudo(MachineInstr &MI, unsigned LowOpcode,
216                                         unsigned Size) const {
217   MachineInstrBuilder MIB =
218     emitGRX32Move(*MI.getParent(), MI, MI.getDebugLoc(),
219                MI.getOperand(0).getReg(), MI.getOperand(1).getReg(), LowOpcode,
220                Size, MI.getOperand(1).isKill(), MI.getOperand(1).isUndef());
221 
222   // Keep the remaining operands as-is.
223   for (const MachineOperand &MO : llvm::drop_begin(MI.operands(), 2))
224     MIB.add(MO);
225 
226   MI.eraseFromParent();
227 }
228 
229 void SystemZInstrInfo::expandLoadStackGuard(MachineInstr *MI) const {
230   MachineBasicBlock *MBB = MI->getParent();
231   MachineFunction &MF = *MBB->getParent();
232   const Register Reg64 = MI->getOperand(0).getReg();
233   const Register Reg32 = RI.getSubReg(Reg64, SystemZ::subreg_l32);
234 
235   // EAR can only load the low subregister so us a shift for %a0 to produce
236   // the GR containing %a0 and %a1.
237 
238   // ear <reg>, %a0
239   BuildMI(*MBB, MI, MI->getDebugLoc(), get(SystemZ::EAR), Reg32)
240     .addReg(SystemZ::A0)
241     .addReg(Reg64, RegState::ImplicitDefine);
242 
243   // sllg <reg>, <reg>, 32
244   BuildMI(*MBB, MI, MI->getDebugLoc(), get(SystemZ::SLLG), Reg64)
245     .addReg(Reg64)
246     .addReg(0)
247     .addImm(32);
248 
249   // ear <reg>, %a1
250   BuildMI(*MBB, MI, MI->getDebugLoc(), get(SystemZ::EAR), Reg32)
251     .addReg(SystemZ::A1);
252 
253   // lg <reg>, 40(<reg>)
254   MI->setDesc(get(SystemZ::LG));
255   MachineInstrBuilder(MF, MI).addReg(Reg64).addImm(40).addReg(0);
256 }
257 
258 // Emit a zero-extending move from 32-bit GPR SrcReg to 32-bit GPR
259 // DestReg before MBBI in MBB.  Use LowLowOpcode when both DestReg and SrcReg
260 // are low registers, otherwise use RISB[LH]G.  Size is the number of bits
261 // taken from the low end of SrcReg (8 for LLCR, 16 for LLHR and 32 for LR).
262 // KillSrc is true if this move is the last use of SrcReg.
263 MachineInstrBuilder
264 SystemZInstrInfo::emitGRX32Move(MachineBasicBlock &MBB,
265                                 MachineBasicBlock::iterator MBBI,
266                                 const DebugLoc &DL, unsigned DestReg,
267                                 unsigned SrcReg, unsigned LowLowOpcode,
268                                 unsigned Size, bool KillSrc,
269                                 bool UndefSrc) const {
270   unsigned Opcode;
271   bool DestIsHigh = SystemZ::isHighReg(DestReg);
272   bool SrcIsHigh = SystemZ::isHighReg(SrcReg);
273   if (DestIsHigh && SrcIsHigh)
274     Opcode = SystemZ::RISBHH;
275   else if (DestIsHigh && !SrcIsHigh)
276     Opcode = SystemZ::RISBHL;
277   else if (!DestIsHigh && SrcIsHigh)
278     Opcode = SystemZ::RISBLH;
279   else {
280     return BuildMI(MBB, MBBI, DL, get(LowLowOpcode), DestReg)
281       .addReg(SrcReg, getKillRegState(KillSrc) | getUndefRegState(UndefSrc));
282   }
283   unsigned Rotate = (DestIsHigh != SrcIsHigh ? 32 : 0);
284   return BuildMI(MBB, MBBI, DL, get(Opcode), DestReg)
285     .addReg(DestReg, RegState::Undef)
286     .addReg(SrcReg, getKillRegState(KillSrc) | getUndefRegState(UndefSrc))
287     .addImm(32 - Size).addImm(128 + 31).addImm(Rotate);
288 }
289 
290 MachineInstr *SystemZInstrInfo::commuteInstructionImpl(MachineInstr &MI,
291                                                        bool NewMI,
292                                                        unsigned OpIdx1,
293                                                        unsigned OpIdx2) const {
294   auto cloneIfNew = [NewMI](MachineInstr &MI) -> MachineInstr & {
295     if (NewMI)
296       return *MI.getParent()->getParent()->CloneMachineInstr(&MI);
297     return MI;
298   };
299 
300   switch (MI.getOpcode()) {
301   case SystemZ::SELRMux:
302   case SystemZ::SELFHR:
303   case SystemZ::SELR:
304   case SystemZ::SELGR:
305   case SystemZ::LOCRMux:
306   case SystemZ::LOCFHR:
307   case SystemZ::LOCR:
308   case SystemZ::LOCGR: {
309     auto &WorkingMI = cloneIfNew(MI);
310     // Invert condition.
311     unsigned CCValid = WorkingMI.getOperand(3).getImm();
312     unsigned CCMask = WorkingMI.getOperand(4).getImm();
313     WorkingMI.getOperand(4).setImm(CCMask ^ CCValid);
314     return TargetInstrInfo::commuteInstructionImpl(WorkingMI, /*NewMI=*/false,
315                                                    OpIdx1, OpIdx2);
316   }
317   default:
318     return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
319   }
320 }
321 
322 // If MI is a simple load or store for a frame object, return the register
323 // it loads or stores and set FrameIndex to the index of the frame object.
324 // Return 0 otherwise.
325 //
326 // Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores.
327 static int isSimpleMove(const MachineInstr &MI, int &FrameIndex,
328                         unsigned Flag) {
329   const MCInstrDesc &MCID = MI.getDesc();
330   if ((MCID.TSFlags & Flag) && MI.getOperand(1).isFI() &&
331       MI.getOperand(2).getImm() == 0 && MI.getOperand(3).getReg() == 0) {
332     FrameIndex = MI.getOperand(1).getIndex();
333     return MI.getOperand(0).getReg();
334   }
335   return 0;
336 }
337 
338 Register SystemZInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
339                                                int &FrameIndex) const {
340   return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXLoad);
341 }
342 
343 Register SystemZInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
344                                               int &FrameIndex) const {
345   return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXStore);
346 }
347 
348 bool SystemZInstrInfo::isStackSlotCopy(const MachineInstr &MI,
349                                        int &DestFrameIndex,
350                                        int &SrcFrameIndex) const {
351   // Check for MVC 0(Length,FI1),0(FI2)
352   const MachineFrameInfo &MFI = MI.getParent()->getParent()->getFrameInfo();
353   if (MI.getOpcode() != SystemZ::MVC || !MI.getOperand(0).isFI() ||
354       MI.getOperand(1).getImm() != 0 || !MI.getOperand(3).isFI() ||
355       MI.getOperand(4).getImm() != 0)
356     return false;
357 
358   // Check that Length covers the full slots.
359   int64_t Length = MI.getOperand(2).getImm();
360   unsigned FI1 = MI.getOperand(0).getIndex();
361   unsigned FI2 = MI.getOperand(3).getIndex();
362   if (MFI.getObjectSize(FI1) != Length ||
363       MFI.getObjectSize(FI2) != Length)
364     return false;
365 
366   DestFrameIndex = FI1;
367   SrcFrameIndex = FI2;
368   return true;
369 }
370 
371 bool SystemZInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
372                                      MachineBasicBlock *&TBB,
373                                      MachineBasicBlock *&FBB,
374                                      SmallVectorImpl<MachineOperand> &Cond,
375                                      bool AllowModify) const {
376   // Most of the code and comments here are boilerplate.
377 
378   // Start from the bottom of the block and work up, examining the
379   // terminator instructions.
380   MachineBasicBlock::iterator I = MBB.end();
381   while (I != MBB.begin()) {
382     --I;
383     if (I->isDebugInstr())
384       continue;
385 
386     // Working from the bottom, when we see a non-terminator instruction, we're
387     // done.
388     if (!isUnpredicatedTerminator(*I))
389       break;
390 
391     // A terminator that isn't a branch can't easily be handled by this
392     // analysis.
393     if (!I->isBranch())
394       return true;
395 
396     // Can't handle indirect branches.
397     SystemZII::Branch Branch(getBranchInfo(*I));
398     if (!Branch.hasMBBTarget())
399       return true;
400 
401     // Punt on compound branches.
402     if (Branch.Type != SystemZII::BranchNormal)
403       return true;
404 
405     if (Branch.CCMask == SystemZ::CCMASK_ANY) {
406       // Handle unconditional branches.
407       if (!AllowModify) {
408         TBB = Branch.getMBBTarget();
409         continue;
410       }
411 
412       // If the block has any instructions after a JMP, delete them.
413       MBB.erase(std::next(I), MBB.end());
414 
415       Cond.clear();
416       FBB = nullptr;
417 
418       // Delete the JMP if it's equivalent to a fall-through.
419       if (MBB.isLayoutSuccessor(Branch.getMBBTarget())) {
420         TBB = nullptr;
421         I->eraseFromParent();
422         I = MBB.end();
423         continue;
424       }
425 
426       // TBB is used to indicate the unconditinal destination.
427       TBB = Branch.getMBBTarget();
428       continue;
429     }
430 
431     // Working from the bottom, handle the first conditional branch.
432     if (Cond.empty()) {
433       // FIXME: add X86-style branch swap
434       FBB = TBB;
435       TBB = Branch.getMBBTarget();
436       Cond.push_back(MachineOperand::CreateImm(Branch.CCValid));
437       Cond.push_back(MachineOperand::CreateImm(Branch.CCMask));
438       continue;
439     }
440 
441     // Handle subsequent conditional branches.
442     assert(Cond.size() == 2 && TBB && "Should have seen a conditional branch");
443 
444     // Only handle the case where all conditional branches branch to the same
445     // destination.
446     if (TBB != Branch.getMBBTarget())
447       return true;
448 
449     // If the conditions are the same, we can leave them alone.
450     unsigned OldCCValid = Cond[0].getImm();
451     unsigned OldCCMask = Cond[1].getImm();
452     if (OldCCValid == Branch.CCValid && OldCCMask == Branch.CCMask)
453       continue;
454 
455     // FIXME: Try combining conditions like X86 does.  Should be easy on Z!
456     return false;
457   }
458 
459   return false;
460 }
461 
462 unsigned SystemZInstrInfo::removeBranch(MachineBasicBlock &MBB,
463                                         int *BytesRemoved) const {
464   assert(!BytesRemoved && "code size not handled");
465 
466   // Most of the code and comments here are boilerplate.
467   MachineBasicBlock::iterator I = MBB.end();
468   unsigned Count = 0;
469 
470   while (I != MBB.begin()) {
471     --I;
472     if (I->isDebugInstr())
473       continue;
474     if (!I->isBranch())
475       break;
476     if (!getBranchInfo(*I).hasMBBTarget())
477       break;
478     // Remove the branch.
479     I->eraseFromParent();
480     I = MBB.end();
481     ++Count;
482   }
483 
484   return Count;
485 }
486 
487 bool SystemZInstrInfo::
488 reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
489   assert(Cond.size() == 2 && "Invalid condition");
490   Cond[1].setImm(Cond[1].getImm() ^ Cond[0].getImm());
491   return false;
492 }
493 
494 unsigned SystemZInstrInfo::insertBranch(MachineBasicBlock &MBB,
495                                         MachineBasicBlock *TBB,
496                                         MachineBasicBlock *FBB,
497                                         ArrayRef<MachineOperand> Cond,
498                                         const DebugLoc &DL,
499                                         int *BytesAdded) const {
500   // In this function we output 32-bit branches, which should always
501   // have enough range.  They can be shortened and relaxed by later code
502   // in the pipeline, if desired.
503 
504   // Shouldn't be a fall through.
505   assert(TBB && "insertBranch must not be told to insert a fallthrough");
506   assert((Cond.size() == 2 || Cond.size() == 0) &&
507          "SystemZ branch conditions have one component!");
508   assert(!BytesAdded && "code size not handled");
509 
510   if (Cond.empty()) {
511     // Unconditional branch?
512     assert(!FBB && "Unconditional branch with multiple successors!");
513     BuildMI(&MBB, DL, get(SystemZ::J)).addMBB(TBB);
514     return 1;
515   }
516 
517   // Conditional branch.
518   unsigned Count = 0;
519   unsigned CCValid = Cond[0].getImm();
520   unsigned CCMask = Cond[1].getImm();
521   BuildMI(&MBB, DL, get(SystemZ::BRC))
522     .addImm(CCValid).addImm(CCMask).addMBB(TBB);
523   ++Count;
524 
525   if (FBB) {
526     // Two-way Conditional branch. Insert the second branch.
527     BuildMI(&MBB, DL, get(SystemZ::J)).addMBB(FBB);
528     ++Count;
529   }
530   return Count;
531 }
532 
533 bool SystemZInstrInfo::analyzeCompare(const MachineInstr &MI, Register &SrcReg,
534                                       Register &SrcReg2, int64_t &Mask,
535                                       int64_t &Value) const {
536   assert(MI.isCompare() && "Caller should have checked for a comparison");
537 
538   if (MI.getNumExplicitOperands() == 2 && MI.getOperand(0).isReg() &&
539       MI.getOperand(1).isImm()) {
540     SrcReg = MI.getOperand(0).getReg();
541     SrcReg2 = 0;
542     Value = MI.getOperand(1).getImm();
543     Mask = ~0;
544     return true;
545   }
546 
547   return false;
548 }
549 
550 bool SystemZInstrInfo::canInsertSelect(const MachineBasicBlock &MBB,
551                                        ArrayRef<MachineOperand> Pred,
552                                        Register DstReg, Register TrueReg,
553                                        Register FalseReg, int &CondCycles,
554                                        int &TrueCycles,
555                                        int &FalseCycles) const {
556   // Not all subtargets have LOCR instructions.
557   if (!STI.hasLoadStoreOnCond())
558     return false;
559   if (Pred.size() != 2)
560     return false;
561 
562   // Check register classes.
563   const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
564   const TargetRegisterClass *RC =
565     RI.getCommonSubClass(MRI.getRegClass(TrueReg), MRI.getRegClass(FalseReg));
566   if (!RC)
567     return false;
568 
569   // We have LOCR instructions for 32 and 64 bit general purpose registers.
570   if ((STI.hasLoadStoreOnCond2() &&
571        SystemZ::GRX32BitRegClass.hasSubClassEq(RC)) ||
572       SystemZ::GR32BitRegClass.hasSubClassEq(RC) ||
573       SystemZ::GR64BitRegClass.hasSubClassEq(RC)) {
574     CondCycles = 2;
575     TrueCycles = 2;
576     FalseCycles = 2;
577     return true;
578   }
579 
580   // Can't do anything else.
581   return false;
582 }
583 
584 void SystemZInstrInfo::insertSelect(MachineBasicBlock &MBB,
585                                     MachineBasicBlock::iterator I,
586                                     const DebugLoc &DL, Register DstReg,
587                                     ArrayRef<MachineOperand> Pred,
588                                     Register TrueReg,
589                                     Register FalseReg) const {
590   MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
591   const TargetRegisterClass *RC = MRI.getRegClass(DstReg);
592 
593   assert(Pred.size() == 2 && "Invalid condition");
594   unsigned CCValid = Pred[0].getImm();
595   unsigned CCMask = Pred[1].getImm();
596 
597   unsigned Opc;
598   if (SystemZ::GRX32BitRegClass.hasSubClassEq(RC)) {
599     if (STI.hasMiscellaneousExtensions3())
600       Opc = SystemZ::SELRMux;
601     else if (STI.hasLoadStoreOnCond2())
602       Opc = SystemZ::LOCRMux;
603     else {
604       Opc = SystemZ::LOCR;
605       MRI.constrainRegClass(DstReg, &SystemZ::GR32BitRegClass);
606       Register TReg = MRI.createVirtualRegister(&SystemZ::GR32BitRegClass);
607       Register FReg = MRI.createVirtualRegister(&SystemZ::GR32BitRegClass);
608       BuildMI(MBB, I, DL, get(TargetOpcode::COPY), TReg).addReg(TrueReg);
609       BuildMI(MBB, I, DL, get(TargetOpcode::COPY), FReg).addReg(FalseReg);
610       TrueReg = TReg;
611       FalseReg = FReg;
612     }
613   } else if (SystemZ::GR64BitRegClass.hasSubClassEq(RC)) {
614     if (STI.hasMiscellaneousExtensions3())
615       Opc = SystemZ::SELGR;
616     else
617       Opc = SystemZ::LOCGR;
618   } else
619     llvm_unreachable("Invalid register class");
620 
621   BuildMI(MBB, I, DL, get(Opc), DstReg)
622     .addReg(FalseReg).addReg(TrueReg)
623     .addImm(CCValid).addImm(CCMask);
624 }
625 
626 MachineInstr *SystemZInstrInfo::optimizeLoadInstr(MachineInstr &MI,
627                                                   const MachineRegisterInfo *MRI,
628                                                   Register &FoldAsLoadDefReg,
629                                                   MachineInstr *&DefMI) const {
630   // Check whether we can move the DefMI load, and that it only has one use.
631   DefMI = MRI->getVRegDef(FoldAsLoadDefReg);
632   assert(DefMI);
633   bool SawStore = false;
634   if (!DefMI->isSafeToMove(nullptr, SawStore) ||
635       !MRI->hasOneNonDBGUse(FoldAsLoadDefReg))
636     return nullptr;
637 
638   int UseOpIdx =
639       MI.findRegisterUseOperandIdx(FoldAsLoadDefReg, /*TRI=*/nullptr);
640   assert(UseOpIdx != -1 && "Expected FoldAsLoadDefReg to be used by MI.");
641 
642   // Check whether we can fold the load.
643   if (MachineInstr *FoldMI =
644           foldMemoryOperand(MI, {((unsigned)UseOpIdx)}, *DefMI)) {
645     FoldAsLoadDefReg = 0;
646     return FoldMI;
647   }
648 
649   return nullptr;
650 }
651 
652 bool SystemZInstrInfo::foldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
653                                      Register Reg,
654                                      MachineRegisterInfo *MRI) const {
655   unsigned DefOpc = DefMI.getOpcode();
656 
657   if (DefOpc == SystemZ::VGBM) {
658     int64_t ImmVal = DefMI.getOperand(1).getImm();
659     if (ImmVal != 0) // TODO: Handle other values
660       return false;
661 
662     // Fold gr128 = COPY (vr128 VGBM imm)
663     //
664     // %tmp:gr64 = LGHI 0
665     // to  gr128 = REG_SEQUENCE %tmp, %tmp
666     assert(DefMI.getOperand(0).getReg() == Reg);
667 
668     if (!UseMI.isCopy())
669       return false;
670 
671     Register CopyDstReg = UseMI.getOperand(0).getReg();
672     if (CopyDstReg.isVirtual() &&
673         MRI->getRegClass(CopyDstReg) == &SystemZ::GR128BitRegClass &&
674         MRI->hasOneNonDBGUse(Reg)) {
675       // TODO: Handle physical registers
676       // TODO: Handle gr64 uses with subregister indexes
677       // TODO: Should this multi-use cases?
678       Register TmpReg = MRI->createVirtualRegister(&SystemZ::GR64BitRegClass);
679       MachineBasicBlock &MBB = *UseMI.getParent();
680 
681       loadImmediate(MBB, UseMI.getIterator(), TmpReg, ImmVal);
682 
683       UseMI.setDesc(get(SystemZ::REG_SEQUENCE));
684       UseMI.getOperand(1).setReg(TmpReg);
685       MachineInstrBuilder(*MBB.getParent(), &UseMI)
686           .addImm(SystemZ::subreg_h64)
687           .addReg(TmpReg)
688           .addImm(SystemZ::subreg_l64);
689 
690       if (MRI->use_nodbg_empty(Reg))
691         DefMI.eraseFromParent();
692       return true;
693     }
694 
695     return false;
696   }
697 
698   if (DefOpc != SystemZ::LHIMux && DefOpc != SystemZ::LHI &&
699       DefOpc != SystemZ::LGHI)
700     return false;
701   if (DefMI.getOperand(0).getReg() != Reg)
702     return false;
703   int32_t ImmVal = (int32_t)DefMI.getOperand(1).getImm();
704 
705   unsigned UseOpc = UseMI.getOpcode();
706   unsigned NewUseOpc;
707   unsigned UseIdx;
708   int CommuteIdx = -1;
709   bool TieOps = false;
710   switch (UseOpc) {
711   case SystemZ::SELRMux:
712     TieOps = true;
713     [[fallthrough]];
714   case SystemZ::LOCRMux:
715     if (!STI.hasLoadStoreOnCond2())
716       return false;
717     NewUseOpc = SystemZ::LOCHIMux;
718     if (UseMI.getOperand(2).getReg() == Reg)
719       UseIdx = 2;
720     else if (UseMI.getOperand(1).getReg() == Reg)
721       UseIdx = 2, CommuteIdx = 1;
722     else
723       return false;
724     break;
725   case SystemZ::SELGR:
726     TieOps = true;
727     [[fallthrough]];
728   case SystemZ::LOCGR:
729     if (!STI.hasLoadStoreOnCond2())
730       return false;
731     NewUseOpc = SystemZ::LOCGHI;
732     if (UseMI.getOperand(2).getReg() == Reg)
733       UseIdx = 2;
734     else if (UseMI.getOperand(1).getReg() == Reg)
735       UseIdx = 2, CommuteIdx = 1;
736     else
737       return false;
738     break;
739   default:
740     return false;
741   }
742 
743   if (CommuteIdx != -1)
744     if (!commuteInstruction(UseMI, false, CommuteIdx, UseIdx))
745       return false;
746 
747   bool DeleteDef = MRI->hasOneNonDBGUse(Reg);
748   UseMI.setDesc(get(NewUseOpc));
749   if (TieOps)
750     UseMI.tieOperands(0, 1);
751   UseMI.getOperand(UseIdx).ChangeToImmediate(ImmVal);
752   if (DeleteDef)
753     DefMI.eraseFromParent();
754 
755   return true;
756 }
757 
758 bool SystemZInstrInfo::isPredicable(const MachineInstr &MI) const {
759   unsigned Opcode = MI.getOpcode();
760   if (Opcode == SystemZ::Return ||
761       Opcode == SystemZ::Return_XPLINK ||
762       Opcode == SystemZ::Trap ||
763       Opcode == SystemZ::CallJG ||
764       Opcode == SystemZ::CallBR)
765     return true;
766   return false;
767 }
768 
769 bool SystemZInstrInfo::
770 isProfitableToIfCvt(MachineBasicBlock &MBB,
771                     unsigned NumCycles, unsigned ExtraPredCycles,
772                     BranchProbability Probability) const {
773   // Avoid using conditional returns at the end of a loop (since then
774   // we'd need to emit an unconditional branch to the beginning anyway,
775   // making the loop body longer).  This doesn't apply for low-probability
776   // loops (eg. compare-and-swap retry), so just decide based on branch
777   // probability instead of looping structure.
778   // However, since Compare and Trap instructions cost the same as a regular
779   // Compare instruction, we should allow the if conversion to convert this
780   // into a Conditional Compare regardless of the branch probability.
781   if (MBB.getLastNonDebugInstr()->getOpcode() != SystemZ::Trap &&
782       MBB.succ_empty() && Probability < BranchProbability(1, 8))
783     return false;
784   // For now only convert single instructions.
785   return NumCycles == 1;
786 }
787 
788 bool SystemZInstrInfo::
789 isProfitableToIfCvt(MachineBasicBlock &TMBB,
790                     unsigned NumCyclesT, unsigned ExtraPredCyclesT,
791                     MachineBasicBlock &FMBB,
792                     unsigned NumCyclesF, unsigned ExtraPredCyclesF,
793                     BranchProbability Probability) const {
794   // For now avoid converting mutually-exclusive cases.
795   return false;
796 }
797 
798 bool SystemZInstrInfo::
799 isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
800                           BranchProbability Probability) const {
801   // For now only duplicate single instructions.
802   return NumCycles == 1;
803 }
804 
805 bool SystemZInstrInfo::PredicateInstruction(
806     MachineInstr &MI, ArrayRef<MachineOperand> Pred) const {
807   assert(Pred.size() == 2 && "Invalid condition");
808   unsigned CCValid = Pred[0].getImm();
809   unsigned CCMask = Pred[1].getImm();
810   assert(CCMask > 0 && CCMask < 15 && "Invalid predicate");
811   unsigned Opcode = MI.getOpcode();
812   if (Opcode == SystemZ::Trap) {
813     MI.setDesc(get(SystemZ::CondTrap));
814     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
815       .addImm(CCValid).addImm(CCMask)
816       .addReg(SystemZ::CC, RegState::Implicit);
817     return true;
818   }
819   if (Opcode == SystemZ::Return || Opcode == SystemZ::Return_XPLINK) {
820     MI.setDesc(get(Opcode == SystemZ::Return ? SystemZ::CondReturn
821                                              : SystemZ::CondReturn_XPLINK));
822     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
823         .addImm(CCValid)
824         .addImm(CCMask)
825         .addReg(SystemZ::CC, RegState::Implicit);
826     return true;
827   }
828   if (Opcode == SystemZ::CallJG) {
829     MachineOperand FirstOp = MI.getOperand(0);
830     const uint32_t *RegMask = MI.getOperand(1).getRegMask();
831     MI.removeOperand(1);
832     MI.removeOperand(0);
833     MI.setDesc(get(SystemZ::CallBRCL));
834     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
835         .addImm(CCValid)
836         .addImm(CCMask)
837         .add(FirstOp)
838         .addRegMask(RegMask)
839         .addReg(SystemZ::CC, RegState::Implicit);
840     return true;
841   }
842   if (Opcode == SystemZ::CallBR) {
843     MachineOperand Target = MI.getOperand(0);
844     const uint32_t *RegMask = MI.getOperand(1).getRegMask();
845     MI.removeOperand(1);
846     MI.removeOperand(0);
847     MI.setDesc(get(SystemZ::CallBCR));
848     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
849       .addImm(CCValid).addImm(CCMask)
850       .add(Target)
851       .addRegMask(RegMask)
852       .addReg(SystemZ::CC, RegState::Implicit);
853     return true;
854   }
855   return false;
856 }
857 
858 void SystemZInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
859                                    MachineBasicBlock::iterator MBBI,
860                                    const DebugLoc &DL, MCRegister DestReg,
861                                    MCRegister SrcReg, bool KillSrc) const {
862   // Split 128-bit GPR moves into two 64-bit moves. Add implicit uses of the
863   // super register in case one of the subregs is undefined.
864   // This handles ADDR128 too.
865   if (SystemZ::GR128BitRegClass.contains(DestReg, SrcReg)) {
866     copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_h64),
867                 RI.getSubReg(SrcReg, SystemZ::subreg_h64), KillSrc);
868     MachineInstrBuilder(*MBB.getParent(), std::prev(MBBI))
869       .addReg(SrcReg, RegState::Implicit);
870     copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_l64),
871                 RI.getSubReg(SrcReg, SystemZ::subreg_l64), KillSrc);
872     MachineInstrBuilder(*MBB.getParent(), std::prev(MBBI))
873       .addReg(SrcReg, (getKillRegState(KillSrc) | RegState::Implicit));
874     return;
875   }
876 
877   if (SystemZ::GRX32BitRegClass.contains(DestReg, SrcReg)) {
878     emitGRX32Move(MBB, MBBI, DL, DestReg, SrcReg, SystemZ::LR, 32, KillSrc,
879                   false);
880     return;
881   }
882 
883   // Move 128-bit floating-point values between VR128 and FP128.
884   if (SystemZ::VR128BitRegClass.contains(DestReg) &&
885       SystemZ::FP128BitRegClass.contains(SrcReg)) {
886     MCRegister SrcRegHi =
887         RI.getMatchingSuperReg(RI.getSubReg(SrcReg, SystemZ::subreg_h64),
888                                SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
889     MCRegister SrcRegLo =
890         RI.getMatchingSuperReg(RI.getSubReg(SrcReg, SystemZ::subreg_l64),
891                                SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
892 
893     BuildMI(MBB, MBBI, DL, get(SystemZ::VMRHG), DestReg)
894       .addReg(SrcRegHi, getKillRegState(KillSrc))
895       .addReg(SrcRegLo, getKillRegState(KillSrc));
896     return;
897   }
898   if (SystemZ::FP128BitRegClass.contains(DestReg) &&
899       SystemZ::VR128BitRegClass.contains(SrcReg)) {
900     MCRegister DestRegHi =
901         RI.getMatchingSuperReg(RI.getSubReg(DestReg, SystemZ::subreg_h64),
902                                SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
903     MCRegister DestRegLo =
904         RI.getMatchingSuperReg(RI.getSubReg(DestReg, SystemZ::subreg_l64),
905                                SystemZ::subreg_h64, &SystemZ::VR128BitRegClass);
906 
907     if (DestRegHi != SrcReg)
908       copyPhysReg(MBB, MBBI, DL, DestRegHi, SrcReg, false);
909     BuildMI(MBB, MBBI, DL, get(SystemZ::VREPG), DestRegLo)
910       .addReg(SrcReg, getKillRegState(KillSrc)).addImm(1);
911     return;
912   }
913 
914   if (SystemZ::FP128BitRegClass.contains(DestReg) &&
915       SystemZ::GR128BitRegClass.contains(SrcReg)) {
916     MCRegister DestRegHi = RI.getSubReg(DestReg, SystemZ::subreg_h64);
917     MCRegister DestRegLo = RI.getSubReg(DestReg, SystemZ::subreg_l64);
918     MCRegister SrcRegHi = RI.getSubReg(SrcReg, SystemZ::subreg_h64);
919     MCRegister SrcRegLo = RI.getSubReg(SrcReg, SystemZ::subreg_l64);
920 
921     BuildMI(MBB, MBBI, DL, get(SystemZ::LDGR), DestRegHi)
922         .addReg(SrcRegHi)
923         .addReg(DestReg, RegState::ImplicitDefine);
924 
925     BuildMI(MBB, MBBI, DL, get(SystemZ::LDGR), DestRegLo)
926         .addReg(SrcRegLo, getKillRegState(KillSrc));
927     return;
928   }
929 
930   // Move CC value from a GR32.
931   if (DestReg == SystemZ::CC) {
932     unsigned Opcode =
933       SystemZ::GR32BitRegClass.contains(SrcReg) ? SystemZ::TMLH : SystemZ::TMHH;
934     BuildMI(MBB, MBBI, DL, get(Opcode))
935       .addReg(SrcReg, getKillRegState(KillSrc))
936       .addImm(3 << (SystemZ::IPM_CC - 16));
937     return;
938   }
939 
940   if (SystemZ::GR128BitRegClass.contains(DestReg) &&
941       SystemZ::VR128BitRegClass.contains(SrcReg)) {
942     MCRegister DestH64 = RI.getSubReg(DestReg, SystemZ::subreg_h64);
943     MCRegister DestL64 = RI.getSubReg(DestReg, SystemZ::subreg_l64);
944 
945     BuildMI(MBB, MBBI, DL, get(SystemZ::VLGVG), DestH64)
946         .addReg(SrcReg)
947         .addReg(SystemZ::NoRegister)
948         .addImm(0)
949         .addDef(DestReg, RegState::Implicit);
950     BuildMI(MBB, MBBI, DL, get(SystemZ::VLGVG), DestL64)
951         .addReg(SrcReg, getKillRegState(KillSrc))
952         .addReg(SystemZ::NoRegister)
953         .addImm(1);
954     return;
955   }
956 
957   if (SystemZ::VR128BitRegClass.contains(DestReg) &&
958       SystemZ::GR128BitRegClass.contains(SrcReg)) {
959     BuildMI(MBB, MBBI, DL, get(SystemZ::VLVGP), DestReg)
960         .addReg(RI.getSubReg(SrcReg, SystemZ::subreg_h64))
961         .addReg(RI.getSubReg(SrcReg, SystemZ::subreg_l64));
962     return;
963   }
964 
965   // Everything else needs only one instruction.
966   unsigned Opcode;
967   if (SystemZ::GR64BitRegClass.contains(DestReg, SrcReg))
968     Opcode = SystemZ::LGR;
969   else if (SystemZ::FP32BitRegClass.contains(DestReg, SrcReg))
970     // For z13 we prefer LDR over LER to avoid partial register dependencies.
971     Opcode = STI.hasVector() ? SystemZ::LDR32 : SystemZ::LER;
972   else if (SystemZ::FP64BitRegClass.contains(DestReg, SrcReg))
973     Opcode = SystemZ::LDR;
974   else if (SystemZ::FP128BitRegClass.contains(DestReg, SrcReg))
975     Opcode = SystemZ::LXR;
976   else if (SystemZ::VR32BitRegClass.contains(DestReg, SrcReg))
977     Opcode = SystemZ::VLR32;
978   else if (SystemZ::VR64BitRegClass.contains(DestReg, SrcReg))
979     Opcode = SystemZ::VLR64;
980   else if (SystemZ::VR128BitRegClass.contains(DestReg, SrcReg))
981     Opcode = SystemZ::VLR;
982   else if (SystemZ::AR32BitRegClass.contains(DestReg, SrcReg))
983     Opcode = SystemZ::CPYA;
984   else
985     llvm_unreachable("Impossible reg-to-reg copy");
986 
987   BuildMI(MBB, MBBI, DL, get(Opcode), DestReg)
988     .addReg(SrcReg, getKillRegState(KillSrc));
989 }
990 
991 void SystemZInstrInfo::storeRegToStackSlot(
992     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, Register SrcReg,
993     bool isKill, int FrameIdx, const TargetRegisterClass *RC,
994     const TargetRegisterInfo *TRI, Register VReg) const {
995   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
996 
997   // Callers may expect a single instruction, so keep 128-bit moves
998   // together for now and lower them after register allocation.
999   unsigned LoadOpcode, StoreOpcode;
1000   getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode);
1001   addFrameReference(BuildMI(MBB, MBBI, DL, get(StoreOpcode))
1002                         .addReg(SrcReg, getKillRegState(isKill)),
1003                     FrameIdx);
1004 }
1005 
1006 void SystemZInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
1007                                             MachineBasicBlock::iterator MBBI,
1008                                             Register DestReg, int FrameIdx,
1009                                             const TargetRegisterClass *RC,
1010                                             const TargetRegisterInfo *TRI,
1011                                             Register VReg) const {
1012   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
1013 
1014   // Callers may expect a single instruction, so keep 128-bit moves
1015   // together for now and lower them after register allocation.
1016   unsigned LoadOpcode, StoreOpcode;
1017   getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode);
1018   addFrameReference(BuildMI(MBB, MBBI, DL, get(LoadOpcode), DestReg),
1019                     FrameIdx);
1020 }
1021 
1022 // Return true if MI is a simple load or store with a 12-bit displacement
1023 // and no index.  Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores.
1024 static bool isSimpleBD12Move(const MachineInstr *MI, unsigned Flag) {
1025   const MCInstrDesc &MCID = MI->getDesc();
1026   return ((MCID.TSFlags & Flag) &&
1027           isUInt<12>(MI->getOperand(2).getImm()) &&
1028           MI->getOperand(3).getReg() == 0);
1029 }
1030 
1031 namespace {
1032 
1033 struct LogicOp {
1034   LogicOp() = default;
1035   LogicOp(unsigned regSize, unsigned immLSB, unsigned immSize)
1036     : RegSize(regSize), ImmLSB(immLSB), ImmSize(immSize) {}
1037 
1038   explicit operator bool() const { return RegSize; }
1039 
1040   unsigned RegSize = 0;
1041   unsigned ImmLSB = 0;
1042   unsigned ImmSize = 0;
1043 };
1044 
1045 } // end anonymous namespace
1046 
1047 static LogicOp interpretAndImmediate(unsigned Opcode) {
1048   switch (Opcode) {
1049   case SystemZ::NILMux: return LogicOp(32,  0, 16);
1050   case SystemZ::NIHMux: return LogicOp(32, 16, 16);
1051   case SystemZ::NILL64: return LogicOp(64,  0, 16);
1052   case SystemZ::NILH64: return LogicOp(64, 16, 16);
1053   case SystemZ::NIHL64: return LogicOp(64, 32, 16);
1054   case SystemZ::NIHH64: return LogicOp(64, 48, 16);
1055   case SystemZ::NIFMux: return LogicOp(32,  0, 32);
1056   case SystemZ::NILF64: return LogicOp(64,  0, 32);
1057   case SystemZ::NIHF64: return LogicOp(64, 32, 32);
1058   default:              return LogicOp();
1059   }
1060 }
1061 
1062 static void transferDeadCC(MachineInstr *OldMI, MachineInstr *NewMI) {
1063   if (OldMI->registerDefIsDead(SystemZ::CC, /*TRI=*/nullptr)) {
1064     MachineOperand *CCDef =
1065         NewMI->findRegisterDefOperand(SystemZ::CC, /*TRI=*/nullptr);
1066     if (CCDef != nullptr)
1067       CCDef->setIsDead(true);
1068   }
1069 }
1070 
1071 static void transferMIFlag(MachineInstr *OldMI, MachineInstr *NewMI,
1072                            MachineInstr::MIFlag Flag) {
1073   if (OldMI->getFlag(Flag))
1074     NewMI->setFlag(Flag);
1075 }
1076 
1077 MachineInstr *
1078 SystemZInstrInfo::convertToThreeAddress(MachineInstr &MI, LiveVariables *LV,
1079                                         LiveIntervals *LIS) const {
1080   MachineBasicBlock *MBB = MI.getParent();
1081 
1082   // Try to convert an AND into an RISBG-type instruction.
1083   // TODO: It might be beneficial to select RISBG and shorten to AND instead.
1084   if (LogicOp And = interpretAndImmediate(MI.getOpcode())) {
1085     uint64_t Imm = MI.getOperand(2).getImm() << And.ImmLSB;
1086     // AND IMMEDIATE leaves the other bits of the register unchanged.
1087     Imm |= allOnes(And.RegSize) & ~(allOnes(And.ImmSize) << And.ImmLSB);
1088     unsigned Start, End;
1089     if (isRxSBGMask(Imm, And.RegSize, Start, End)) {
1090       unsigned NewOpcode;
1091       if (And.RegSize == 64) {
1092         NewOpcode = SystemZ::RISBG;
1093         // Prefer RISBGN if available, since it does not clobber CC.
1094         if (STI.hasMiscellaneousExtensions())
1095           NewOpcode = SystemZ::RISBGN;
1096       } else {
1097         NewOpcode = SystemZ::RISBMux;
1098         Start &= 31;
1099         End &= 31;
1100       }
1101       MachineOperand &Dest = MI.getOperand(0);
1102       MachineOperand &Src = MI.getOperand(1);
1103       MachineInstrBuilder MIB =
1104           BuildMI(*MBB, MI, MI.getDebugLoc(), get(NewOpcode))
1105               .add(Dest)
1106               .addReg(0)
1107               .addReg(Src.getReg(), getKillRegState(Src.isKill()),
1108                       Src.getSubReg())
1109               .addImm(Start)
1110               .addImm(End + 128)
1111               .addImm(0);
1112       if (LV) {
1113         unsigned NumOps = MI.getNumOperands();
1114         for (unsigned I = 1; I < NumOps; ++I) {
1115           MachineOperand &Op = MI.getOperand(I);
1116           if (Op.isReg() && Op.isKill())
1117             LV->replaceKillInstruction(Op.getReg(), MI, *MIB);
1118         }
1119       }
1120       if (LIS)
1121         LIS->ReplaceMachineInstrInMaps(MI, *MIB);
1122       transferDeadCC(&MI, MIB);
1123       return MIB;
1124     }
1125   }
1126   return nullptr;
1127 }
1128 
1129 bool SystemZInstrInfo::isAssociativeAndCommutative(const MachineInstr &Inst,
1130                                                    bool Invert) const {
1131   unsigned Opc = Inst.getOpcode();
1132   if (Invert) {
1133     auto InverseOpcode = getInverseOpcode(Opc);
1134     if (!InverseOpcode)
1135       return false;
1136     Opc = *InverseOpcode;
1137   }
1138 
1139   switch (Opc) {
1140   default:
1141     break;
1142   // Adds and multiplications.
1143   case SystemZ::WFADB:
1144   case SystemZ::WFASB:
1145   case SystemZ::WFAXB:
1146   case SystemZ::VFADB:
1147   case SystemZ::VFASB:
1148   case SystemZ::WFMDB:
1149   case SystemZ::WFMSB:
1150   case SystemZ::WFMXB:
1151   case SystemZ::VFMDB:
1152   case SystemZ::VFMSB:
1153     return (Inst.getFlag(MachineInstr::MIFlag::FmReassoc) &&
1154             Inst.getFlag(MachineInstr::MIFlag::FmNsz));
1155   }
1156 
1157   return false;
1158 }
1159 
1160 std::optional<unsigned>
1161 SystemZInstrInfo::getInverseOpcode(unsigned Opcode) const {
1162   // fadd => fsub
1163   switch (Opcode) {
1164   case SystemZ::WFADB:
1165     return SystemZ::WFSDB;
1166   case SystemZ::WFASB:
1167     return SystemZ::WFSSB;
1168   case SystemZ::WFAXB:
1169     return SystemZ::WFSXB;
1170   case SystemZ::VFADB:
1171     return SystemZ::VFSDB;
1172   case SystemZ::VFASB:
1173     return SystemZ::VFSSB;
1174   // fsub => fadd
1175   case SystemZ::WFSDB:
1176     return SystemZ::WFADB;
1177   case SystemZ::WFSSB:
1178     return SystemZ::WFASB;
1179   case SystemZ::WFSXB:
1180     return SystemZ::WFAXB;
1181   case SystemZ::VFSDB:
1182     return SystemZ::VFADB;
1183   case SystemZ::VFSSB:
1184     return SystemZ::VFASB;
1185   default:
1186     return std::nullopt;
1187   }
1188 }
1189 
1190 MachineInstr *SystemZInstrInfo::foldMemoryOperandImpl(
1191     MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
1192     MachineBasicBlock::iterator InsertPt, int FrameIndex,
1193     LiveIntervals *LIS, VirtRegMap *VRM) const {
1194   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
1195   MachineRegisterInfo &MRI = MF.getRegInfo();
1196   const MachineFrameInfo &MFI = MF.getFrameInfo();
1197   unsigned Size = MFI.getObjectSize(FrameIndex);
1198   unsigned Opcode = MI.getOpcode();
1199 
1200   // Check CC liveness if new instruction introduces a dead def of CC.
1201   SlotIndex MISlot = SlotIndex();
1202   LiveRange *CCLiveRange = nullptr;
1203   bool CCLiveAtMI = true;
1204   if (LIS) {
1205     MISlot = LIS->getSlotIndexes()->getInstructionIndex(MI).getRegSlot();
1206     auto CCUnits = TRI->regunits(MCRegister::from(SystemZ::CC));
1207     assert(range_size(CCUnits) == 1 && "CC only has one reg unit.");
1208     CCLiveRange = &LIS->getRegUnit(*CCUnits.begin());
1209     CCLiveAtMI = CCLiveRange->liveAt(MISlot);
1210   }
1211 
1212   if (Ops.size() == 2 && Ops[0] == 0 && Ops[1] == 1) {
1213     if (!CCLiveAtMI && (Opcode == SystemZ::LA || Opcode == SystemZ::LAY) &&
1214         isInt<8>(MI.getOperand(2).getImm()) && !MI.getOperand(3).getReg()) {
1215       // LA(Y) %reg, CONST(%reg) -> AGSI %mem, CONST
1216       MachineInstr *BuiltMI = BuildMI(*InsertPt->getParent(), InsertPt,
1217                                       MI.getDebugLoc(), get(SystemZ::AGSI))
1218         .addFrameIndex(FrameIndex)
1219         .addImm(0)
1220         .addImm(MI.getOperand(2).getImm());
1221       BuiltMI->findRegisterDefOperand(SystemZ::CC, /*TRI=*/nullptr)
1222           ->setIsDead(true);
1223       CCLiveRange->createDeadDef(MISlot, LIS->getVNInfoAllocator());
1224       return BuiltMI;
1225     }
1226     return nullptr;
1227   }
1228 
1229   // All other cases require a single operand.
1230   if (Ops.size() != 1)
1231     return nullptr;
1232 
1233   unsigned OpNum = Ops[0];
1234   assert(Size * 8 ==
1235            TRI->getRegSizeInBits(*MF.getRegInfo()
1236                                .getRegClass(MI.getOperand(OpNum).getReg())) &&
1237          "Invalid size combination");
1238 
1239   if ((Opcode == SystemZ::AHI || Opcode == SystemZ::AGHI) && OpNum == 0 &&
1240       isInt<8>(MI.getOperand(2).getImm())) {
1241     // A(G)HI %reg, CONST -> A(G)SI %mem, CONST
1242     Opcode = (Opcode == SystemZ::AHI ? SystemZ::ASI : SystemZ::AGSI);
1243     MachineInstr *BuiltMI =
1244         BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(), get(Opcode))
1245             .addFrameIndex(FrameIndex)
1246             .addImm(0)
1247             .addImm(MI.getOperand(2).getImm());
1248     transferDeadCC(&MI, BuiltMI);
1249     transferMIFlag(&MI, BuiltMI, MachineInstr::NoSWrap);
1250     return BuiltMI;
1251   }
1252 
1253   if ((Opcode == SystemZ::ALFI && OpNum == 0 &&
1254        isInt<8>((int32_t)MI.getOperand(2).getImm())) ||
1255       (Opcode == SystemZ::ALGFI && OpNum == 0 &&
1256        isInt<8>((int64_t)MI.getOperand(2).getImm()))) {
1257     // AL(G)FI %reg, CONST -> AL(G)SI %mem, CONST
1258     Opcode = (Opcode == SystemZ::ALFI ? SystemZ::ALSI : SystemZ::ALGSI);
1259     MachineInstr *BuiltMI =
1260         BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(), get(Opcode))
1261             .addFrameIndex(FrameIndex)
1262             .addImm(0)
1263             .addImm((int8_t)MI.getOperand(2).getImm());
1264     transferDeadCC(&MI, BuiltMI);
1265     return BuiltMI;
1266   }
1267 
1268   if ((Opcode == SystemZ::SLFI && OpNum == 0 &&
1269        isInt<8>((int32_t)-MI.getOperand(2).getImm())) ||
1270       (Opcode == SystemZ::SLGFI && OpNum == 0 &&
1271        isInt<8>((int64_t)-MI.getOperand(2).getImm()))) {
1272     // SL(G)FI %reg, CONST -> AL(G)SI %mem, -CONST
1273     Opcode = (Opcode == SystemZ::SLFI ? SystemZ::ALSI : SystemZ::ALGSI);
1274     MachineInstr *BuiltMI =
1275         BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(), get(Opcode))
1276             .addFrameIndex(FrameIndex)
1277             .addImm(0)
1278             .addImm((int8_t)-MI.getOperand(2).getImm());
1279     transferDeadCC(&MI, BuiltMI);
1280     return BuiltMI;
1281   }
1282 
1283   unsigned MemImmOpc = 0;
1284   switch (Opcode) {
1285   case SystemZ::LHIMux:
1286   case SystemZ::LHI:    MemImmOpc = SystemZ::MVHI;  break;
1287   case SystemZ::LGHI:   MemImmOpc = SystemZ::MVGHI; break;
1288   case SystemZ::CHIMux:
1289   case SystemZ::CHI:    MemImmOpc = SystemZ::CHSI;  break;
1290   case SystemZ::CGHI:   MemImmOpc = SystemZ::CGHSI; break;
1291   case SystemZ::CLFIMux:
1292   case SystemZ::CLFI:
1293     if (isUInt<16>(MI.getOperand(1).getImm()))
1294       MemImmOpc = SystemZ::CLFHSI;
1295     break;
1296   case SystemZ::CLGFI:
1297     if (isUInt<16>(MI.getOperand(1).getImm()))
1298       MemImmOpc = SystemZ::CLGHSI;
1299     break;
1300   default: break;
1301   }
1302   if (MemImmOpc)
1303     return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
1304                    get(MemImmOpc))
1305                .addFrameIndex(FrameIndex)
1306                .addImm(0)
1307                .addImm(MI.getOperand(1).getImm());
1308 
1309   if (Opcode == SystemZ::LGDR || Opcode == SystemZ::LDGR) {
1310     bool Op0IsGPR = (Opcode == SystemZ::LGDR);
1311     bool Op1IsGPR = (Opcode == SystemZ::LDGR);
1312     // If we're spilling the destination of an LDGR or LGDR, store the
1313     // source register instead.
1314     if (OpNum == 0) {
1315       unsigned StoreOpcode = Op1IsGPR ? SystemZ::STG : SystemZ::STD;
1316       return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
1317                      get(StoreOpcode))
1318           .add(MI.getOperand(1))
1319           .addFrameIndex(FrameIndex)
1320           .addImm(0)
1321           .addReg(0);
1322     }
1323     // If we're spilling the source of an LDGR or LGDR, load the
1324     // destination register instead.
1325     if (OpNum == 1) {
1326       unsigned LoadOpcode = Op0IsGPR ? SystemZ::LG : SystemZ::LD;
1327       return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
1328                      get(LoadOpcode))
1329         .add(MI.getOperand(0))
1330         .addFrameIndex(FrameIndex)
1331         .addImm(0)
1332         .addReg(0);
1333     }
1334   }
1335 
1336   // Look for cases where the source of a simple store or the destination
1337   // of a simple load is being spilled.  Try to use MVC instead.
1338   //
1339   // Although MVC is in practice a fast choice in these cases, it is still
1340   // logically a bytewise copy.  This means that we cannot use it if the
1341   // load or store is volatile.  We also wouldn't be able to use MVC if
1342   // the two memories partially overlap, but that case cannot occur here,
1343   // because we know that one of the memories is a full frame index.
1344   //
1345   // For performance reasons, we also want to avoid using MVC if the addresses
1346   // might be equal.  We don't worry about that case here, because spill slot
1347   // coloring happens later, and because we have special code to remove
1348   // MVCs that turn out to be redundant.
1349   if (OpNum == 0 && MI.hasOneMemOperand()) {
1350     MachineMemOperand *MMO = *MI.memoperands_begin();
1351     if (MMO->getSize() == Size && !MMO->isVolatile() && !MMO->isAtomic()) {
1352       // Handle conversion of loads.
1353       if (isSimpleBD12Move(&MI, SystemZII::SimpleBDXLoad)) {
1354         return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
1355                        get(SystemZ::MVC))
1356             .addFrameIndex(FrameIndex)
1357             .addImm(0)
1358             .addImm(Size)
1359             .add(MI.getOperand(1))
1360             .addImm(MI.getOperand(2).getImm())
1361             .addMemOperand(MMO);
1362       }
1363       // Handle conversion of stores.
1364       if (isSimpleBD12Move(&MI, SystemZII::SimpleBDXStore)) {
1365         return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
1366                        get(SystemZ::MVC))
1367             .add(MI.getOperand(1))
1368             .addImm(MI.getOperand(2).getImm())
1369             .addImm(Size)
1370             .addFrameIndex(FrameIndex)
1371             .addImm(0)
1372             .addMemOperand(MMO);
1373       }
1374     }
1375   }
1376 
1377   // If the spilled operand is the final one or the instruction is
1378   // commutable, try to change <INSN>R into <INSN>.  Don't introduce a def of
1379   // CC if it is live and MI does not define it.
1380   unsigned NumOps = MI.getNumExplicitOperands();
1381   int MemOpcode = SystemZ::getMemOpcode(Opcode);
1382   if (MemOpcode == -1 ||
1383       (CCLiveAtMI && !MI.definesRegister(SystemZ::CC, /*TRI=*/nullptr) &&
1384        get(MemOpcode).hasImplicitDefOfPhysReg(SystemZ::CC)))
1385     return nullptr;
1386 
1387   // Check if all other vregs have a usable allocation in the case of vector
1388   // to FP conversion.
1389   const MCInstrDesc &MCID = MI.getDesc();
1390   for (unsigned I = 0, E = MCID.getNumOperands(); I != E; ++I) {
1391     const MCOperandInfo &MCOI = MCID.operands()[I];
1392     if (MCOI.OperandType != MCOI::OPERAND_REGISTER || I == OpNum)
1393       continue;
1394     const TargetRegisterClass *RC = TRI->getRegClass(MCOI.RegClass);
1395     if (RC == &SystemZ::VR32BitRegClass || RC == &SystemZ::VR64BitRegClass) {
1396       Register Reg = MI.getOperand(I).getReg();
1397       Register PhysReg = Reg.isVirtual()
1398                              ? (VRM ? Register(VRM->getPhys(Reg)) : Register())
1399                              : Reg;
1400       if (!PhysReg ||
1401           !(SystemZ::FP32BitRegClass.contains(PhysReg) ||
1402             SystemZ::FP64BitRegClass.contains(PhysReg) ||
1403             SystemZ::VF128BitRegClass.contains(PhysReg)))
1404         return nullptr;
1405     }
1406   }
1407   // Fused multiply and add/sub need to have the same dst and accumulator reg.
1408   bool FusedFPOp = (Opcode == SystemZ::WFMADB || Opcode == SystemZ::WFMASB ||
1409                     Opcode == SystemZ::WFMSDB || Opcode == SystemZ::WFMSSB);
1410   if (FusedFPOp) {
1411     Register DstReg = VRM->getPhys(MI.getOperand(0).getReg());
1412     Register AccReg = VRM->getPhys(MI.getOperand(3).getReg());
1413     if (OpNum == 0 || OpNum == 3 || DstReg != AccReg)
1414       return nullptr;
1415   }
1416 
1417   // Try to swap compare operands if possible.
1418   bool NeedsCommute = false;
1419   if ((MI.getOpcode() == SystemZ::CR || MI.getOpcode() == SystemZ::CGR ||
1420        MI.getOpcode() == SystemZ::CLR || MI.getOpcode() == SystemZ::CLGR ||
1421        MI.getOpcode() == SystemZ::WFCDB || MI.getOpcode() == SystemZ::WFCSB ||
1422        MI.getOpcode() == SystemZ::WFKDB || MI.getOpcode() == SystemZ::WFKSB) &&
1423       OpNum == 0 && prepareCompareSwapOperands(MI))
1424     NeedsCommute = true;
1425 
1426   bool CCOperands = false;
1427   if (MI.getOpcode() == SystemZ::LOCRMux || MI.getOpcode() == SystemZ::LOCGR ||
1428       MI.getOpcode() == SystemZ::SELRMux || MI.getOpcode() == SystemZ::SELGR) {
1429     assert(MI.getNumOperands() == 6 && NumOps == 5 &&
1430            "LOCR/SELR instruction operands corrupt?");
1431     NumOps -= 2;
1432     CCOperands = true;
1433   }
1434 
1435   // See if this is a 3-address instruction that is convertible to 2-address
1436   // and suitable for folding below.  Only try this with virtual registers
1437   // and a provided VRM (during regalloc).
1438   if (NumOps == 3 && SystemZ::getTargetMemOpcode(MemOpcode) != -1) {
1439     if (VRM == nullptr)
1440       return nullptr;
1441     else {
1442       Register DstReg = MI.getOperand(0).getReg();
1443       Register DstPhys =
1444           (DstReg.isVirtual() ? Register(VRM->getPhys(DstReg)) : DstReg);
1445       Register SrcReg = (OpNum == 2 ? MI.getOperand(1).getReg()
1446                                     : ((OpNum == 1 && MI.isCommutable())
1447                                            ? MI.getOperand(2).getReg()
1448                                            : Register()));
1449       if (DstPhys && !SystemZ::GRH32BitRegClass.contains(DstPhys) && SrcReg &&
1450           SrcReg.isVirtual() && DstPhys == VRM->getPhys(SrcReg))
1451         NeedsCommute = (OpNum == 1);
1452       else
1453         return nullptr;
1454     }
1455   }
1456 
1457   if ((OpNum == NumOps - 1) || NeedsCommute || FusedFPOp) {
1458     const MCInstrDesc &MemDesc = get(MemOpcode);
1459     uint64_t AccessBytes = SystemZII::getAccessSize(MemDesc.TSFlags);
1460     assert(AccessBytes != 0 && "Size of access should be known");
1461     assert(AccessBytes <= Size && "Access outside the frame index");
1462     uint64_t Offset = Size - AccessBytes;
1463     MachineInstrBuilder MIB = BuildMI(*InsertPt->getParent(), InsertPt,
1464                                       MI.getDebugLoc(), get(MemOpcode));
1465     if (MI.isCompare()) {
1466       assert(NumOps == 2 && "Expected 2 register operands for a compare.");
1467       MIB.add(MI.getOperand(NeedsCommute ? 1 : 0));
1468     }
1469     else if (FusedFPOp) {
1470       MIB.add(MI.getOperand(0));
1471       MIB.add(MI.getOperand(3));
1472       MIB.add(MI.getOperand(OpNum == 1 ? 2 : 1));
1473     }
1474     else {
1475       MIB.add(MI.getOperand(0));
1476       if (NeedsCommute)
1477         MIB.add(MI.getOperand(2));
1478       else
1479         for (unsigned I = 1; I < OpNum; ++I)
1480           MIB.add(MI.getOperand(I));
1481     }
1482     MIB.addFrameIndex(FrameIndex).addImm(Offset);
1483     if (MemDesc.TSFlags & SystemZII::HasIndex)
1484       MIB.addReg(0);
1485     if (CCOperands) {
1486       unsigned CCValid = MI.getOperand(NumOps).getImm();
1487       unsigned CCMask = MI.getOperand(NumOps + 1).getImm();
1488       MIB.addImm(CCValid);
1489       MIB.addImm(NeedsCommute ? CCMask ^ CCValid : CCMask);
1490     }
1491     if (MIB->definesRegister(SystemZ::CC, /*TRI=*/nullptr) &&
1492         (!MI.definesRegister(SystemZ::CC, /*TRI=*/nullptr) ||
1493          MI.registerDefIsDead(SystemZ::CC, /*TRI=*/nullptr))) {
1494       MIB->addRegisterDead(SystemZ::CC, TRI);
1495       if (CCLiveRange)
1496         CCLiveRange->createDeadDef(MISlot, LIS->getVNInfoAllocator());
1497     }
1498     // Constrain the register classes if converted from a vector opcode. The
1499     // allocated regs are in an FP reg-class per previous check above.
1500     for (const MachineOperand &MO : MIB->operands())
1501       if (MO.isReg() && MO.getReg().isVirtual()) {
1502         Register Reg = MO.getReg();
1503         if (MRI.getRegClass(Reg) == &SystemZ::VR32BitRegClass)
1504           MRI.setRegClass(Reg, &SystemZ::FP32BitRegClass);
1505         else if (MRI.getRegClass(Reg) == &SystemZ::VR64BitRegClass)
1506           MRI.setRegClass(Reg, &SystemZ::FP64BitRegClass);
1507         else if (MRI.getRegClass(Reg) == &SystemZ::VR128BitRegClass)
1508           MRI.setRegClass(Reg, &SystemZ::VF128BitRegClass);
1509       }
1510 
1511     transferDeadCC(&MI, MIB);
1512     transferMIFlag(&MI, MIB, MachineInstr::NoSWrap);
1513     transferMIFlag(&MI, MIB, MachineInstr::NoFPExcept);
1514     return MIB;
1515   }
1516 
1517   return nullptr;
1518 }
1519 
1520 MachineInstr *SystemZInstrInfo::foldMemoryOperandImpl(
1521     MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
1522     MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
1523     LiveIntervals *LIS) const {
1524   MachineRegisterInfo *MRI = &MF.getRegInfo();
1525   MachineBasicBlock *MBB = MI.getParent();
1526 
1527   // For reassociable FP operations, any loads have been purposefully left
1528   // unfolded so that MachineCombiner can do its work on reg/reg
1529   // opcodes. After that, as many loads as possible are now folded.
1530   // TODO: This may be beneficial with other opcodes as well as machine-sink
1531   // can move loads close to their user in a different MBB, which the isel
1532   // matcher did not see.
1533   unsigned LoadOpc = 0;
1534   unsigned RegMemOpcode = 0;
1535   const TargetRegisterClass *FPRC = nullptr;
1536   RegMemOpcode = MI.getOpcode() == SystemZ::WFADB   ? SystemZ::ADB
1537                  : MI.getOpcode() == SystemZ::WFSDB ? SystemZ::SDB
1538                  : MI.getOpcode() == SystemZ::WFMDB ? SystemZ::MDB
1539                                                     : 0;
1540   if (RegMemOpcode) {
1541     LoadOpc = SystemZ::VL64;
1542     FPRC = &SystemZ::FP64BitRegClass;
1543   } else {
1544     RegMemOpcode = MI.getOpcode() == SystemZ::WFASB   ? SystemZ::AEB
1545                    : MI.getOpcode() == SystemZ::WFSSB ? SystemZ::SEB
1546                    : MI.getOpcode() == SystemZ::WFMSB ? SystemZ::MEEB
1547                                                       : 0;
1548     if (RegMemOpcode) {
1549       LoadOpc = SystemZ::VL32;
1550       FPRC = &SystemZ::FP32BitRegClass;
1551     }
1552   }
1553   if (!RegMemOpcode || LoadMI.getOpcode() != LoadOpc)
1554     return nullptr;
1555 
1556   // If RegMemOpcode clobbers CC, first make sure CC is not live at this point.
1557   if (get(RegMemOpcode).hasImplicitDefOfPhysReg(SystemZ::CC)) {
1558     assert(LoadMI.getParent() == MI.getParent() && "Assuming a local fold.");
1559     assert(LoadMI != InsertPt && "Assuming InsertPt not to be first in MBB.");
1560     for (MachineBasicBlock::iterator MII = std::prev(InsertPt);;
1561          --MII) {
1562       if (MII->definesRegister(SystemZ::CC, /*TRI=*/nullptr)) {
1563         if (!MII->registerDefIsDead(SystemZ::CC, /*TRI=*/nullptr))
1564           return nullptr;
1565         break;
1566       }
1567       if (MII == MBB->begin()) {
1568         if (MBB->isLiveIn(SystemZ::CC))
1569           return nullptr;
1570         break;
1571       }
1572     }
1573   }
1574 
1575   Register FoldAsLoadDefReg = LoadMI.getOperand(0).getReg();
1576   if (Ops.size() != 1 || FoldAsLoadDefReg != MI.getOperand(Ops[0]).getReg())
1577     return nullptr;
1578   Register DstReg = MI.getOperand(0).getReg();
1579   MachineOperand LHS = MI.getOperand(1);
1580   MachineOperand RHS = MI.getOperand(2);
1581   MachineOperand &RegMO = RHS.getReg() == FoldAsLoadDefReg ? LHS : RHS;
1582   if ((RegMemOpcode == SystemZ::SDB || RegMemOpcode == SystemZ::SEB) &&
1583       FoldAsLoadDefReg != RHS.getReg())
1584     return nullptr;
1585 
1586   MachineOperand &Base = LoadMI.getOperand(1);
1587   MachineOperand &Disp = LoadMI.getOperand(2);
1588   MachineOperand &Indx = LoadMI.getOperand(3);
1589   MachineInstrBuilder MIB =
1590       BuildMI(*MI.getParent(), InsertPt, MI.getDebugLoc(), get(RegMemOpcode), DstReg)
1591           .add(RegMO)
1592           .add(Base)
1593           .add(Disp)
1594           .add(Indx);
1595   MIB->addRegisterDead(SystemZ::CC, &RI);
1596   MRI->setRegClass(DstReg, FPRC);
1597   MRI->setRegClass(RegMO.getReg(), FPRC);
1598   transferMIFlag(&MI, MIB, MachineInstr::NoFPExcept);
1599 
1600   return MIB;
1601 }
1602 
1603 bool SystemZInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
1604   switch (MI.getOpcode()) {
1605   case SystemZ::L128:
1606     splitMove(MI, SystemZ::LG);
1607     return true;
1608 
1609   case SystemZ::ST128:
1610     splitMove(MI, SystemZ::STG);
1611     return true;
1612 
1613   case SystemZ::LX:
1614     splitMove(MI, SystemZ::LD);
1615     return true;
1616 
1617   case SystemZ::STX:
1618     splitMove(MI, SystemZ::STD);
1619     return true;
1620 
1621   case SystemZ::LBMux:
1622     expandRXYPseudo(MI, SystemZ::LB, SystemZ::LBH);
1623     return true;
1624 
1625   case SystemZ::LHMux:
1626     expandRXYPseudo(MI, SystemZ::LH, SystemZ::LHH);
1627     return true;
1628 
1629   case SystemZ::LLCRMux:
1630     expandZExtPseudo(MI, SystemZ::LLCR, 8);
1631     return true;
1632 
1633   case SystemZ::LLHRMux:
1634     expandZExtPseudo(MI, SystemZ::LLHR, 16);
1635     return true;
1636 
1637   case SystemZ::LLCMux:
1638     expandRXYPseudo(MI, SystemZ::LLC, SystemZ::LLCH);
1639     return true;
1640 
1641   case SystemZ::LLHMux:
1642     expandRXYPseudo(MI, SystemZ::LLH, SystemZ::LLHH);
1643     return true;
1644 
1645   case SystemZ::LMux:
1646     expandRXYPseudo(MI, SystemZ::L, SystemZ::LFH);
1647     return true;
1648 
1649   case SystemZ::LOCMux:
1650     expandLOCPseudo(MI, SystemZ::LOC, SystemZ::LOCFH);
1651     return true;
1652 
1653   case SystemZ::LOCHIMux:
1654     expandLOCPseudo(MI, SystemZ::LOCHI, SystemZ::LOCHHI);
1655     return true;
1656 
1657   case SystemZ::STCMux:
1658     expandRXYPseudo(MI, SystemZ::STC, SystemZ::STCH);
1659     return true;
1660 
1661   case SystemZ::STHMux:
1662     expandRXYPseudo(MI, SystemZ::STH, SystemZ::STHH);
1663     return true;
1664 
1665   case SystemZ::STMux:
1666     expandRXYPseudo(MI, SystemZ::ST, SystemZ::STFH);
1667     return true;
1668 
1669   case SystemZ::STOCMux:
1670     expandLOCPseudo(MI, SystemZ::STOC, SystemZ::STOCFH);
1671     return true;
1672 
1673   case SystemZ::LHIMux:
1674     expandRIPseudo(MI, SystemZ::LHI, SystemZ::IIHF, true);
1675     return true;
1676 
1677   case SystemZ::IIFMux:
1678     expandRIPseudo(MI, SystemZ::IILF, SystemZ::IIHF, false);
1679     return true;
1680 
1681   case SystemZ::IILMux:
1682     expandRIPseudo(MI, SystemZ::IILL, SystemZ::IIHL, false);
1683     return true;
1684 
1685   case SystemZ::IIHMux:
1686     expandRIPseudo(MI, SystemZ::IILH, SystemZ::IIHH, false);
1687     return true;
1688 
1689   case SystemZ::NIFMux:
1690     expandRIPseudo(MI, SystemZ::NILF, SystemZ::NIHF, false);
1691     return true;
1692 
1693   case SystemZ::NILMux:
1694     expandRIPseudo(MI, SystemZ::NILL, SystemZ::NIHL, false);
1695     return true;
1696 
1697   case SystemZ::NIHMux:
1698     expandRIPseudo(MI, SystemZ::NILH, SystemZ::NIHH, false);
1699     return true;
1700 
1701   case SystemZ::OIFMux:
1702     expandRIPseudo(MI, SystemZ::OILF, SystemZ::OIHF, false);
1703     return true;
1704 
1705   case SystemZ::OILMux:
1706     expandRIPseudo(MI, SystemZ::OILL, SystemZ::OIHL, false);
1707     return true;
1708 
1709   case SystemZ::OIHMux:
1710     expandRIPseudo(MI, SystemZ::OILH, SystemZ::OIHH, false);
1711     return true;
1712 
1713   case SystemZ::XIFMux:
1714     expandRIPseudo(MI, SystemZ::XILF, SystemZ::XIHF, false);
1715     return true;
1716 
1717   case SystemZ::TMLMux:
1718     expandRIPseudo(MI, SystemZ::TMLL, SystemZ::TMHL, false);
1719     return true;
1720 
1721   case SystemZ::TMHMux:
1722     expandRIPseudo(MI, SystemZ::TMLH, SystemZ::TMHH, false);
1723     return true;
1724 
1725   case SystemZ::AHIMux:
1726     expandRIPseudo(MI, SystemZ::AHI, SystemZ::AIH, false);
1727     return true;
1728 
1729   case SystemZ::AHIMuxK:
1730     expandRIEPseudo(MI, SystemZ::AHI, SystemZ::AHIK, SystemZ::AIH);
1731     return true;
1732 
1733   case SystemZ::AFIMux:
1734     expandRIPseudo(MI, SystemZ::AFI, SystemZ::AIH, false);
1735     return true;
1736 
1737   case SystemZ::CHIMux:
1738     expandRIPseudo(MI, SystemZ::CHI, SystemZ::CIH, false);
1739     return true;
1740 
1741   case SystemZ::CFIMux:
1742     expandRIPseudo(MI, SystemZ::CFI, SystemZ::CIH, false);
1743     return true;
1744 
1745   case SystemZ::CLFIMux:
1746     expandRIPseudo(MI, SystemZ::CLFI, SystemZ::CLIH, false);
1747     return true;
1748 
1749   case SystemZ::CMux:
1750     expandRXYPseudo(MI, SystemZ::C, SystemZ::CHF);
1751     return true;
1752 
1753   case SystemZ::CLMux:
1754     expandRXYPseudo(MI, SystemZ::CL, SystemZ::CLHF);
1755     return true;
1756 
1757   case SystemZ::RISBMux: {
1758     bool DestIsHigh = SystemZ::isHighReg(MI.getOperand(0).getReg());
1759     bool SrcIsHigh = SystemZ::isHighReg(MI.getOperand(2).getReg());
1760     if (SrcIsHigh == DestIsHigh)
1761       MI.setDesc(get(DestIsHigh ? SystemZ::RISBHH : SystemZ::RISBLL));
1762     else {
1763       MI.setDesc(get(DestIsHigh ? SystemZ::RISBHL : SystemZ::RISBLH));
1764       MI.getOperand(5).setImm(MI.getOperand(5).getImm() ^ 32);
1765     }
1766     return true;
1767   }
1768 
1769   case SystemZ::ADJDYNALLOC:
1770     splitAdjDynAlloc(MI);
1771     return true;
1772 
1773   case TargetOpcode::LOAD_STACK_GUARD:
1774     expandLoadStackGuard(&MI);
1775     return true;
1776 
1777   default:
1778     return false;
1779   }
1780 }
1781 
1782 unsigned SystemZInstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
1783   if (MI.isInlineAsm()) {
1784     const MachineFunction *MF = MI.getParent()->getParent();
1785     const char *AsmStr = MI.getOperand(0).getSymbolName();
1786     return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
1787   }
1788   else if (MI.getOpcode() == SystemZ::PATCHPOINT)
1789     return PatchPointOpers(&MI).getNumPatchBytes();
1790   else if (MI.getOpcode() == SystemZ::STACKMAP)
1791     return MI.getOperand(1).getImm();
1792   else if (MI.getOpcode() == SystemZ::FENTRY_CALL)
1793     return 6;
1794 
1795   return MI.getDesc().getSize();
1796 }
1797 
1798 SystemZII::Branch
1799 SystemZInstrInfo::getBranchInfo(const MachineInstr &MI) const {
1800   switch (MI.getOpcode()) {
1801   case SystemZ::BR:
1802   case SystemZ::BI:
1803   case SystemZ::J:
1804   case SystemZ::JG:
1805     return SystemZII::Branch(SystemZII::BranchNormal, SystemZ::CCMASK_ANY,
1806                              SystemZ::CCMASK_ANY, &MI.getOperand(0));
1807 
1808   case SystemZ::BRC:
1809   case SystemZ::BRCL:
1810     return SystemZII::Branch(SystemZII::BranchNormal, MI.getOperand(0).getImm(),
1811                              MI.getOperand(1).getImm(), &MI.getOperand(2));
1812 
1813   case SystemZ::BRCT:
1814   case SystemZ::BRCTH:
1815     return SystemZII::Branch(SystemZII::BranchCT, SystemZ::CCMASK_ICMP,
1816                              SystemZ::CCMASK_CMP_NE, &MI.getOperand(2));
1817 
1818   case SystemZ::BRCTG:
1819     return SystemZII::Branch(SystemZII::BranchCTG, SystemZ::CCMASK_ICMP,
1820                              SystemZ::CCMASK_CMP_NE, &MI.getOperand(2));
1821 
1822   case SystemZ::CIJ:
1823   case SystemZ::CRJ:
1824     return SystemZII::Branch(SystemZII::BranchC, SystemZ::CCMASK_ICMP,
1825                              MI.getOperand(2).getImm(), &MI.getOperand(3));
1826 
1827   case SystemZ::CLIJ:
1828   case SystemZ::CLRJ:
1829     return SystemZII::Branch(SystemZII::BranchCL, SystemZ::CCMASK_ICMP,
1830                              MI.getOperand(2).getImm(), &MI.getOperand(3));
1831 
1832   case SystemZ::CGIJ:
1833   case SystemZ::CGRJ:
1834     return SystemZII::Branch(SystemZII::BranchCG, SystemZ::CCMASK_ICMP,
1835                              MI.getOperand(2).getImm(), &MI.getOperand(3));
1836 
1837   case SystemZ::CLGIJ:
1838   case SystemZ::CLGRJ:
1839     return SystemZII::Branch(SystemZII::BranchCLG, SystemZ::CCMASK_ICMP,
1840                              MI.getOperand(2).getImm(), &MI.getOperand(3));
1841 
1842   case SystemZ::INLINEASM_BR:
1843     // Don't try to analyze asm goto, so pass nullptr as branch target argument.
1844     return SystemZII::Branch(SystemZII::AsmGoto, 0, 0, nullptr);
1845 
1846   default:
1847     llvm_unreachable("Unrecognized branch opcode");
1848   }
1849 }
1850 
1851 void SystemZInstrInfo::getLoadStoreOpcodes(const TargetRegisterClass *RC,
1852                                            unsigned &LoadOpcode,
1853                                            unsigned &StoreOpcode) const {
1854   if (RC == &SystemZ::GR32BitRegClass || RC == &SystemZ::ADDR32BitRegClass) {
1855     LoadOpcode = SystemZ::L;
1856     StoreOpcode = SystemZ::ST;
1857   } else if (RC == &SystemZ::GRH32BitRegClass) {
1858     LoadOpcode = SystemZ::LFH;
1859     StoreOpcode = SystemZ::STFH;
1860   } else if (RC == &SystemZ::GRX32BitRegClass) {
1861     LoadOpcode = SystemZ::LMux;
1862     StoreOpcode = SystemZ::STMux;
1863   } else if (RC == &SystemZ::GR64BitRegClass ||
1864              RC == &SystemZ::ADDR64BitRegClass) {
1865     LoadOpcode = SystemZ::LG;
1866     StoreOpcode = SystemZ::STG;
1867   } else if (RC == &SystemZ::GR128BitRegClass ||
1868              RC == &SystemZ::ADDR128BitRegClass) {
1869     LoadOpcode = SystemZ::L128;
1870     StoreOpcode = SystemZ::ST128;
1871   } else if (RC == &SystemZ::FP32BitRegClass) {
1872     LoadOpcode = SystemZ::LE;
1873     StoreOpcode = SystemZ::STE;
1874   } else if (RC == &SystemZ::FP64BitRegClass) {
1875     LoadOpcode = SystemZ::LD;
1876     StoreOpcode = SystemZ::STD;
1877   } else if (RC == &SystemZ::FP128BitRegClass) {
1878     LoadOpcode = SystemZ::LX;
1879     StoreOpcode = SystemZ::STX;
1880   } else if (RC == &SystemZ::VR32BitRegClass) {
1881     LoadOpcode = SystemZ::VL32;
1882     StoreOpcode = SystemZ::VST32;
1883   } else if (RC == &SystemZ::VR64BitRegClass) {
1884     LoadOpcode = SystemZ::VL64;
1885     StoreOpcode = SystemZ::VST64;
1886   } else if (RC == &SystemZ::VF128BitRegClass ||
1887              RC == &SystemZ::VR128BitRegClass) {
1888     LoadOpcode = SystemZ::VL;
1889     StoreOpcode = SystemZ::VST;
1890   } else
1891     llvm_unreachable("Unsupported regclass to load or store");
1892 }
1893 
1894 unsigned SystemZInstrInfo::getOpcodeForOffset(unsigned Opcode,
1895                                               int64_t Offset,
1896                                               const MachineInstr *MI) const {
1897   const MCInstrDesc &MCID = get(Opcode);
1898   int64_t Offset2 = (MCID.TSFlags & SystemZII::Is128Bit ? Offset + 8 : Offset);
1899   if (isUInt<12>(Offset) && isUInt<12>(Offset2)) {
1900     // Get the instruction to use for unsigned 12-bit displacements.
1901     int Disp12Opcode = SystemZ::getDisp12Opcode(Opcode);
1902     if (Disp12Opcode >= 0)
1903       return Disp12Opcode;
1904 
1905     // All address-related instructions can use unsigned 12-bit
1906     // displacements.
1907     return Opcode;
1908   }
1909   if (isInt<20>(Offset) && isInt<20>(Offset2)) {
1910     // Get the instruction to use for signed 20-bit displacements.
1911     int Disp20Opcode = SystemZ::getDisp20Opcode(Opcode);
1912     if (Disp20Opcode >= 0)
1913       return Disp20Opcode;
1914 
1915     // Check whether Opcode allows signed 20-bit displacements.
1916     if (MCID.TSFlags & SystemZII::Has20BitOffset)
1917       return Opcode;
1918 
1919     // If a VR32/VR64 reg ended up in an FP register, use the FP opcode.
1920     if (MI && MI->getOperand(0).isReg()) {
1921       Register Reg = MI->getOperand(0).getReg();
1922       if (Reg.isPhysical() && SystemZMC::getFirstReg(Reg) < 16) {
1923         switch (Opcode) {
1924         case SystemZ::VL32:
1925           return SystemZ::LEY;
1926         case SystemZ::VST32:
1927           return SystemZ::STEY;
1928         case SystemZ::VL64:
1929           return SystemZ::LDY;
1930         case SystemZ::VST64:
1931           return SystemZ::STDY;
1932         default: break;
1933         }
1934       }
1935     }
1936   }
1937   return 0;
1938 }
1939 
1940 bool SystemZInstrInfo::hasDisplacementPairInsn(unsigned Opcode) const {
1941   const MCInstrDesc &MCID = get(Opcode);
1942   if (MCID.TSFlags & SystemZII::Has20BitOffset)
1943     return SystemZ::getDisp12Opcode(Opcode) >= 0;
1944   return SystemZ::getDisp20Opcode(Opcode) >= 0;
1945 }
1946 
1947 unsigned SystemZInstrInfo::getLoadAndTest(unsigned Opcode) const {
1948   switch (Opcode) {
1949   case SystemZ::L:      return SystemZ::LT;
1950   case SystemZ::LY:     return SystemZ::LT;
1951   case SystemZ::LG:     return SystemZ::LTG;
1952   case SystemZ::LGF:    return SystemZ::LTGF;
1953   case SystemZ::LR:     return SystemZ::LTR;
1954   case SystemZ::LGFR:   return SystemZ::LTGFR;
1955   case SystemZ::LGR:    return SystemZ::LTGR;
1956   case SystemZ::LCDFR:  return SystemZ::LCDBR;
1957   case SystemZ::LPDFR:  return SystemZ::LPDBR;
1958   case SystemZ::LNDFR:  return SystemZ::LNDBR;
1959   case SystemZ::LCDFR_32:  return SystemZ::LCEBR;
1960   case SystemZ::LPDFR_32:  return SystemZ::LPEBR;
1961   case SystemZ::LNDFR_32:  return SystemZ::LNEBR;
1962   // On zEC12 we prefer to use RISBGN.  But if there is a chance to
1963   // actually use the condition code, we may turn it back into RISGB.
1964   // Note that RISBG is not really a "load-and-test" instruction,
1965   // but sets the same condition code values, so is OK to use here.
1966   case SystemZ::RISBGN: return SystemZ::RISBG;
1967   default:              return 0;
1968   }
1969 }
1970 
1971 bool SystemZInstrInfo::isRxSBGMask(uint64_t Mask, unsigned BitSize,
1972                                    unsigned &Start, unsigned &End) const {
1973   // Reject trivial all-zero masks.
1974   Mask &= allOnes(BitSize);
1975   if (Mask == 0)
1976     return false;
1977 
1978   // Handle the 1+0+ or 0+1+0* cases.  Start then specifies the index of
1979   // the msb and End specifies the index of the lsb.
1980   unsigned LSB, Length;
1981   if (isShiftedMask_64(Mask, LSB, Length)) {
1982     Start = 63 - (LSB + Length - 1);
1983     End = 63 - LSB;
1984     return true;
1985   }
1986 
1987   // Handle the wrap-around 1+0+1+ cases.  Start then specifies the msb
1988   // of the low 1s and End specifies the lsb of the high 1s.
1989   if (isShiftedMask_64(Mask ^ allOnes(BitSize), LSB, Length)) {
1990     assert(LSB > 0 && "Bottom bit must be set");
1991     assert(LSB + Length < BitSize && "Top bit must be set");
1992     Start = 63 - (LSB - 1);
1993     End = 63 - (LSB + Length);
1994     return true;
1995   }
1996 
1997   return false;
1998 }
1999 
2000 unsigned SystemZInstrInfo::getFusedCompare(unsigned Opcode,
2001                                            SystemZII::FusedCompareType Type,
2002                                            const MachineInstr *MI) const {
2003   switch (Opcode) {
2004   case SystemZ::CHI:
2005   case SystemZ::CGHI:
2006     if (!(MI && isInt<8>(MI->getOperand(1).getImm())))
2007       return 0;
2008     break;
2009   case SystemZ::CLFI:
2010   case SystemZ::CLGFI:
2011     if (!(MI && isUInt<8>(MI->getOperand(1).getImm())))
2012       return 0;
2013     break;
2014   case SystemZ::CL:
2015   case SystemZ::CLG:
2016     if (!STI.hasMiscellaneousExtensions())
2017       return 0;
2018     if (!(MI && MI->getOperand(3).getReg() == 0))
2019       return 0;
2020     break;
2021   }
2022   switch (Type) {
2023   case SystemZII::CompareAndBranch:
2024     switch (Opcode) {
2025     case SystemZ::CR:
2026       return SystemZ::CRJ;
2027     case SystemZ::CGR:
2028       return SystemZ::CGRJ;
2029     case SystemZ::CHI:
2030       return SystemZ::CIJ;
2031     case SystemZ::CGHI:
2032       return SystemZ::CGIJ;
2033     case SystemZ::CLR:
2034       return SystemZ::CLRJ;
2035     case SystemZ::CLGR:
2036       return SystemZ::CLGRJ;
2037     case SystemZ::CLFI:
2038       return SystemZ::CLIJ;
2039     case SystemZ::CLGFI:
2040       return SystemZ::CLGIJ;
2041     default:
2042       return 0;
2043     }
2044   case SystemZII::CompareAndReturn:
2045     switch (Opcode) {
2046     case SystemZ::CR:
2047       return SystemZ::CRBReturn;
2048     case SystemZ::CGR:
2049       return SystemZ::CGRBReturn;
2050     case SystemZ::CHI:
2051       return SystemZ::CIBReturn;
2052     case SystemZ::CGHI:
2053       return SystemZ::CGIBReturn;
2054     case SystemZ::CLR:
2055       return SystemZ::CLRBReturn;
2056     case SystemZ::CLGR:
2057       return SystemZ::CLGRBReturn;
2058     case SystemZ::CLFI:
2059       return SystemZ::CLIBReturn;
2060     case SystemZ::CLGFI:
2061       return SystemZ::CLGIBReturn;
2062     default:
2063       return 0;
2064     }
2065   case SystemZII::CompareAndSibcall:
2066     switch (Opcode) {
2067     case SystemZ::CR:
2068       return SystemZ::CRBCall;
2069     case SystemZ::CGR:
2070       return SystemZ::CGRBCall;
2071     case SystemZ::CHI:
2072       return SystemZ::CIBCall;
2073     case SystemZ::CGHI:
2074       return SystemZ::CGIBCall;
2075     case SystemZ::CLR:
2076       return SystemZ::CLRBCall;
2077     case SystemZ::CLGR:
2078       return SystemZ::CLGRBCall;
2079     case SystemZ::CLFI:
2080       return SystemZ::CLIBCall;
2081     case SystemZ::CLGFI:
2082       return SystemZ::CLGIBCall;
2083     default:
2084       return 0;
2085     }
2086   case SystemZII::CompareAndTrap:
2087     switch (Opcode) {
2088     case SystemZ::CR:
2089       return SystemZ::CRT;
2090     case SystemZ::CGR:
2091       return SystemZ::CGRT;
2092     case SystemZ::CHI:
2093       return SystemZ::CIT;
2094     case SystemZ::CGHI:
2095       return SystemZ::CGIT;
2096     case SystemZ::CLR:
2097       return SystemZ::CLRT;
2098     case SystemZ::CLGR:
2099       return SystemZ::CLGRT;
2100     case SystemZ::CLFI:
2101       return SystemZ::CLFIT;
2102     case SystemZ::CLGFI:
2103       return SystemZ::CLGIT;
2104     case SystemZ::CL:
2105       return SystemZ::CLT;
2106     case SystemZ::CLG:
2107       return SystemZ::CLGT;
2108     default:
2109       return 0;
2110     }
2111   }
2112   return 0;
2113 }
2114 
2115 bool SystemZInstrInfo::
2116 prepareCompareSwapOperands(MachineBasicBlock::iterator const MBBI) const {
2117   assert(MBBI->isCompare() && MBBI->getOperand(0).isReg() &&
2118          MBBI->getOperand(1).isReg() && !MBBI->mayLoad() &&
2119          "Not a compare reg/reg.");
2120 
2121   MachineBasicBlock *MBB = MBBI->getParent();
2122   bool CCLive = true;
2123   SmallVector<MachineInstr *, 4> CCUsers;
2124   for (MachineInstr &MI : llvm::make_range(std::next(MBBI), MBB->end())) {
2125     if (MI.readsRegister(SystemZ::CC, /*TRI=*/nullptr)) {
2126       unsigned Flags = MI.getDesc().TSFlags;
2127       if ((Flags & SystemZII::CCMaskFirst) || (Flags & SystemZII::CCMaskLast))
2128         CCUsers.push_back(&MI);
2129       else
2130         return false;
2131     }
2132     if (MI.definesRegister(SystemZ::CC, /*TRI=*/nullptr)) {
2133       CCLive = false;
2134       break;
2135     }
2136   }
2137   if (CCLive) {
2138     LiveRegUnits LiveRegs(*MBB->getParent()->getSubtarget().getRegisterInfo());
2139     LiveRegs.addLiveOuts(*MBB);
2140     if (!LiveRegs.available(SystemZ::CC))
2141       return false;
2142   }
2143 
2144   // Update all CC users.
2145   for (unsigned Idx = 0; Idx < CCUsers.size(); ++Idx) {
2146     unsigned Flags = CCUsers[Idx]->getDesc().TSFlags;
2147     unsigned FirstOpNum = ((Flags & SystemZII::CCMaskFirst) ?
2148                            0 : CCUsers[Idx]->getNumExplicitOperands() - 2);
2149     MachineOperand &CCMaskMO = CCUsers[Idx]->getOperand(FirstOpNum + 1);
2150     unsigned NewCCMask = SystemZ::reverseCCMask(CCMaskMO.getImm());
2151     CCMaskMO.setImm(NewCCMask);
2152   }
2153 
2154   return true;
2155 }
2156 
2157 unsigned SystemZ::reverseCCMask(unsigned CCMask) {
2158   return ((CCMask & SystemZ::CCMASK_CMP_EQ) |
2159           ((CCMask & SystemZ::CCMASK_CMP_GT) ? SystemZ::CCMASK_CMP_LT : 0) |
2160           ((CCMask & SystemZ::CCMASK_CMP_LT) ? SystemZ::CCMASK_CMP_GT : 0) |
2161           (CCMask & SystemZ::CCMASK_CMP_UO));
2162 }
2163 
2164 MachineBasicBlock *SystemZ::emitBlockAfter(MachineBasicBlock *MBB) {
2165   MachineFunction &MF = *MBB->getParent();
2166   MachineBasicBlock *NewMBB = MF.CreateMachineBasicBlock(MBB->getBasicBlock());
2167   MF.insert(std::next(MachineFunction::iterator(MBB)), NewMBB);
2168   return NewMBB;
2169 }
2170 
2171 MachineBasicBlock *SystemZ::splitBlockAfter(MachineBasicBlock::iterator MI,
2172                                             MachineBasicBlock *MBB) {
2173   MachineBasicBlock *NewMBB = emitBlockAfter(MBB);
2174   NewMBB->splice(NewMBB->begin(), MBB,
2175                  std::next(MachineBasicBlock::iterator(MI)), MBB->end());
2176   NewMBB->transferSuccessorsAndUpdatePHIs(MBB);
2177   return NewMBB;
2178 }
2179 
2180 MachineBasicBlock *SystemZ::splitBlockBefore(MachineBasicBlock::iterator MI,
2181                                              MachineBasicBlock *MBB) {
2182   MachineBasicBlock *NewMBB = emitBlockAfter(MBB);
2183   NewMBB->splice(NewMBB->begin(), MBB, MI, MBB->end());
2184   NewMBB->transferSuccessorsAndUpdatePHIs(MBB);
2185   return NewMBB;
2186 }
2187 
2188 unsigned SystemZInstrInfo::getLoadAndTrap(unsigned Opcode) const {
2189   if (!STI.hasLoadAndTrap())
2190     return 0;
2191   switch (Opcode) {
2192   case SystemZ::L:
2193   case SystemZ::LY:
2194     return SystemZ::LAT;
2195   case SystemZ::LG:
2196     return SystemZ::LGAT;
2197   case SystemZ::LFH:
2198     return SystemZ::LFHAT;
2199   case SystemZ::LLGF:
2200     return SystemZ::LLGFAT;
2201   case SystemZ::LLGT:
2202     return SystemZ::LLGTAT;
2203   }
2204   return 0;
2205 }
2206 
2207 void SystemZInstrInfo::loadImmediate(MachineBasicBlock &MBB,
2208                                      MachineBasicBlock::iterator MBBI,
2209                                      unsigned Reg, uint64_t Value) const {
2210   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
2211   unsigned Opcode = 0;
2212   if (isInt<16>(Value))
2213     Opcode = SystemZ::LGHI;
2214   else if (SystemZ::isImmLL(Value))
2215     Opcode = SystemZ::LLILL;
2216   else if (SystemZ::isImmLH(Value)) {
2217     Opcode = SystemZ::LLILH;
2218     Value >>= 16;
2219   }
2220   else if (isInt<32>(Value))
2221     Opcode = SystemZ::LGFI;
2222   if (Opcode) {
2223     BuildMI(MBB, MBBI, DL, get(Opcode), Reg).addImm(Value);
2224     return;
2225   }
2226 
2227   MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
2228   assert (MRI.isSSA() &&  "Huge values only handled before reg-alloc .");
2229   Register Reg0 = MRI.createVirtualRegister(&SystemZ::GR64BitRegClass);
2230   Register Reg1 = MRI.createVirtualRegister(&SystemZ::GR64BitRegClass);
2231   BuildMI(MBB, MBBI, DL, get(SystemZ::IMPLICIT_DEF), Reg0);
2232   BuildMI(MBB, MBBI, DL, get(SystemZ::IIHF64), Reg1)
2233     .addReg(Reg0).addImm(Value >> 32);
2234   BuildMI(MBB, MBBI, DL, get(SystemZ::IILF64), Reg)
2235     .addReg(Reg1).addImm(Value & ((uint64_t(1) << 32) - 1));
2236 }
2237 
2238 bool SystemZInstrInfo::verifyInstruction(const MachineInstr &MI,
2239                                          StringRef &ErrInfo) const {
2240   const MCInstrDesc &MCID = MI.getDesc();
2241   for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
2242     if (I >= MCID.getNumOperands())
2243       break;
2244     const MachineOperand &Op = MI.getOperand(I);
2245     const MCOperandInfo &MCOI = MCID.operands()[I];
2246     // Addressing modes have register and immediate operands. Op should be a
2247     // register (or frame index) operand if MCOI.RegClass contains a valid
2248     // register class, or an immediate otherwise.
2249     if (MCOI.OperandType == MCOI::OPERAND_MEMORY &&
2250         ((MCOI.RegClass != -1 && !Op.isReg() && !Op.isFI()) ||
2251          (MCOI.RegClass == -1 && !Op.isImm()))) {
2252       ErrInfo = "Addressing mode operands corrupt!";
2253       return false;
2254     }
2255   }
2256 
2257   return true;
2258 }
2259 
2260 bool SystemZInstrInfo::
2261 areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
2262                                 const MachineInstr &MIb) const {
2263 
2264   if (!MIa.hasOneMemOperand() || !MIb.hasOneMemOperand())
2265     return false;
2266 
2267   // If mem-operands show that the same address Value is used by both
2268   // instructions, check for non-overlapping offsets and widths. Not
2269   // sure if a register based analysis would be an improvement...
2270 
2271   MachineMemOperand *MMOa = *MIa.memoperands_begin();
2272   MachineMemOperand *MMOb = *MIb.memoperands_begin();
2273   const Value *VALa = MMOa->getValue();
2274   const Value *VALb = MMOb->getValue();
2275   bool SameVal = (VALa && VALb && (VALa == VALb));
2276   if (!SameVal) {
2277     const PseudoSourceValue *PSVa = MMOa->getPseudoValue();
2278     const PseudoSourceValue *PSVb = MMOb->getPseudoValue();
2279     if (PSVa && PSVb && (PSVa == PSVb))
2280       SameVal = true;
2281   }
2282   if (SameVal) {
2283     int OffsetA = MMOa->getOffset(), OffsetB = MMOb->getOffset();
2284     LocationSize WidthA = MMOa->getSize(), WidthB = MMOb->getSize();
2285     int LowOffset = OffsetA < OffsetB ? OffsetA : OffsetB;
2286     int HighOffset = OffsetA < OffsetB ? OffsetB : OffsetA;
2287     LocationSize LowWidth = (LowOffset == OffsetA) ? WidthA : WidthB;
2288     if (LowWidth.hasValue() &&
2289         LowOffset + (int)LowWidth.getValue() <= HighOffset)
2290       return true;
2291   }
2292 
2293   return false;
2294 }
2295 
2296 bool SystemZInstrInfo::getConstValDefinedInReg(const MachineInstr &MI,
2297                                                const Register Reg,
2298                                                int64_t &ImmVal) const {
2299 
2300   if (MI.getOpcode() == SystemZ::VGBM && Reg == MI.getOperand(0).getReg()) {
2301     ImmVal = MI.getOperand(1).getImm();
2302     // TODO: Handle non-0 values
2303     return ImmVal == 0;
2304   }
2305 
2306   return false;
2307 }
2308