xref: /freebsd/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVExpandPseudoInsts.cpp (revision a8089ea5aee578e08acab2438e82fc9a9ae50ed8)
1 //===-- RISCVExpandPseudoInsts.cpp - Expand pseudo instructions -----------===//
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 a pass that expands pseudo instructions into target
10 // instructions. This pass should be run after register allocation but before
11 // the post-regalloc scheduling pass.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "RISCV.h"
16 #include "RISCVInstrInfo.h"
17 #include "RISCVTargetMachine.h"
18 
19 #include "llvm/CodeGen/LivePhysRegs.h"
20 #include "llvm/CodeGen/MachineFunctionPass.h"
21 #include "llvm/CodeGen/MachineInstrBuilder.h"
22 #include "llvm/MC/MCContext.h"
23 
24 using namespace llvm;
25 
26 #define RISCV_EXPAND_PSEUDO_NAME "RISC-V pseudo instruction expansion pass"
27 #define RISCV_PRERA_EXPAND_PSEUDO_NAME "RISC-V Pre-RA pseudo instruction expansion pass"
28 
29 namespace {
30 
31 class RISCVExpandPseudo : public MachineFunctionPass {
32 public:
33   const RISCVSubtarget *STI;
34   const RISCVInstrInfo *TII;
35   static char ID;
36 
37   RISCVExpandPseudo() : MachineFunctionPass(ID) {}
38 
39   bool runOnMachineFunction(MachineFunction &MF) override;
40 
41   StringRef getPassName() const override { return RISCV_EXPAND_PSEUDO_NAME; }
42 
43 private:
44   bool expandMBB(MachineBasicBlock &MBB);
45   bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
46                 MachineBasicBlock::iterator &NextMBBI);
47   bool expandCCOp(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
48                   MachineBasicBlock::iterator &NextMBBI);
49   bool expandVSetVL(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
50   bool expandVMSET_VMCLR(MachineBasicBlock &MBB,
51                          MachineBasicBlock::iterator MBBI, unsigned Opcode);
52   bool expandRV32ZdinxStore(MachineBasicBlock &MBB,
53                             MachineBasicBlock::iterator MBBI);
54   bool expandRV32ZdinxLoad(MachineBasicBlock &MBB,
55                            MachineBasicBlock::iterator MBBI);
56 #ifndef NDEBUG
57   unsigned getInstSizeInBytes(const MachineFunction &MF) const {
58     unsigned Size = 0;
59     for (auto &MBB : MF)
60       for (auto &MI : MBB)
61         Size += TII->getInstSizeInBytes(MI);
62     return Size;
63   }
64 #endif
65 };
66 
67 char RISCVExpandPseudo::ID = 0;
68 
69 bool RISCVExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
70   STI = &MF.getSubtarget<RISCVSubtarget>();
71   TII = STI->getInstrInfo();
72 
73 #ifndef NDEBUG
74   const unsigned OldSize = getInstSizeInBytes(MF);
75 #endif
76 
77   bool Modified = false;
78   for (auto &MBB : MF)
79     Modified |= expandMBB(MBB);
80 
81 #ifndef NDEBUG
82   const unsigned NewSize = getInstSizeInBytes(MF);
83   assert(OldSize >= NewSize);
84 #endif
85   return Modified;
86 }
87 
88 bool RISCVExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
89   bool Modified = false;
90 
91   MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
92   while (MBBI != E) {
93     MachineBasicBlock::iterator NMBBI = std::next(MBBI);
94     Modified |= expandMI(MBB, MBBI, NMBBI);
95     MBBI = NMBBI;
96   }
97 
98   return Modified;
99 }
100 
101 bool RISCVExpandPseudo::expandMI(MachineBasicBlock &MBB,
102                                  MachineBasicBlock::iterator MBBI,
103                                  MachineBasicBlock::iterator &NextMBBI) {
104   // RISCVInstrInfo::getInstSizeInBytes expects that the total size of the
105   // expanded instructions for each pseudo is correct in the Size field of the
106   // tablegen definition for the pseudo.
107   switch (MBBI->getOpcode()) {
108   case RISCV::PseudoRV32ZdinxSD:
109     return expandRV32ZdinxStore(MBB, MBBI);
110   case RISCV::PseudoRV32ZdinxLD:
111     return expandRV32ZdinxLoad(MBB, MBBI);
112   case RISCV::PseudoCCMOVGPRNoX0:
113   case RISCV::PseudoCCMOVGPR:
114   case RISCV::PseudoCCADD:
115   case RISCV::PseudoCCSUB:
116   case RISCV::PseudoCCAND:
117   case RISCV::PseudoCCOR:
118   case RISCV::PseudoCCXOR:
119   case RISCV::PseudoCCADDW:
120   case RISCV::PseudoCCSUBW:
121   case RISCV::PseudoCCSLL:
122   case RISCV::PseudoCCSRL:
123   case RISCV::PseudoCCSRA:
124   case RISCV::PseudoCCADDI:
125   case RISCV::PseudoCCSLLI:
126   case RISCV::PseudoCCSRLI:
127   case RISCV::PseudoCCSRAI:
128   case RISCV::PseudoCCANDI:
129   case RISCV::PseudoCCORI:
130   case RISCV::PseudoCCXORI:
131   case RISCV::PseudoCCSLLW:
132   case RISCV::PseudoCCSRLW:
133   case RISCV::PseudoCCSRAW:
134   case RISCV::PseudoCCADDIW:
135   case RISCV::PseudoCCSLLIW:
136   case RISCV::PseudoCCSRLIW:
137   case RISCV::PseudoCCSRAIW:
138   case RISCV::PseudoCCANDN:
139   case RISCV::PseudoCCORN:
140   case RISCV::PseudoCCXNOR:
141     return expandCCOp(MBB, MBBI, NextMBBI);
142   case RISCV::PseudoVSETVLI:
143   case RISCV::PseudoVSETVLIX0:
144   case RISCV::PseudoVSETIVLI:
145     return expandVSetVL(MBB, MBBI);
146   case RISCV::PseudoVMCLR_M_B1:
147   case RISCV::PseudoVMCLR_M_B2:
148   case RISCV::PseudoVMCLR_M_B4:
149   case RISCV::PseudoVMCLR_M_B8:
150   case RISCV::PseudoVMCLR_M_B16:
151   case RISCV::PseudoVMCLR_M_B32:
152   case RISCV::PseudoVMCLR_M_B64:
153     // vmclr.m vd => vmxor.mm vd, vd, vd
154     return expandVMSET_VMCLR(MBB, MBBI, RISCV::VMXOR_MM);
155   case RISCV::PseudoVMSET_M_B1:
156   case RISCV::PseudoVMSET_M_B2:
157   case RISCV::PseudoVMSET_M_B4:
158   case RISCV::PseudoVMSET_M_B8:
159   case RISCV::PseudoVMSET_M_B16:
160   case RISCV::PseudoVMSET_M_B32:
161   case RISCV::PseudoVMSET_M_B64:
162     // vmset.m vd => vmxnor.mm vd, vd, vd
163     return expandVMSET_VMCLR(MBB, MBBI, RISCV::VMXNOR_MM);
164   }
165 
166   return false;
167 }
168 
169 bool RISCVExpandPseudo::expandCCOp(MachineBasicBlock &MBB,
170                                    MachineBasicBlock::iterator MBBI,
171                                    MachineBasicBlock::iterator &NextMBBI) {
172 
173   MachineFunction *MF = MBB.getParent();
174   MachineInstr &MI = *MBBI;
175   DebugLoc DL = MI.getDebugLoc();
176 
177   MachineBasicBlock *TrueBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock());
178   MachineBasicBlock *MergeBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock());
179 
180   MF->insert(++MBB.getIterator(), TrueBB);
181   MF->insert(++TrueBB->getIterator(), MergeBB);
182 
183   // We want to copy the "true" value when the condition is true which means
184   // we need to invert the branch condition to jump over TrueBB when the
185   // condition is false.
186   auto CC = static_cast<RISCVCC::CondCode>(MI.getOperand(3).getImm());
187   CC = RISCVCC::getOppositeBranchCondition(CC);
188 
189   // Insert branch instruction.
190   BuildMI(MBB, MBBI, DL, TII->getBrCond(CC))
191       .addReg(MI.getOperand(1).getReg())
192       .addReg(MI.getOperand(2).getReg())
193       .addMBB(MergeBB);
194 
195   Register DestReg = MI.getOperand(0).getReg();
196   assert(MI.getOperand(4).getReg() == DestReg);
197 
198   if (MI.getOpcode() == RISCV::PseudoCCMOVGPR ||
199       MI.getOpcode() == RISCV::PseudoCCMOVGPRNoX0) {
200     // Add MV.
201     BuildMI(TrueBB, DL, TII->get(RISCV::ADDI), DestReg)
202         .add(MI.getOperand(5))
203         .addImm(0);
204   } else {
205     unsigned NewOpc;
206     switch (MI.getOpcode()) {
207     default:
208       llvm_unreachable("Unexpected opcode!");
209     case RISCV::PseudoCCADD:   NewOpc = RISCV::ADD;   break;
210     case RISCV::PseudoCCSUB:   NewOpc = RISCV::SUB;   break;
211     case RISCV::PseudoCCSLL:   NewOpc = RISCV::SLL;   break;
212     case RISCV::PseudoCCSRL:   NewOpc = RISCV::SRL;   break;
213     case RISCV::PseudoCCSRA:   NewOpc = RISCV::SRA;   break;
214     case RISCV::PseudoCCAND:   NewOpc = RISCV::AND;   break;
215     case RISCV::PseudoCCOR:    NewOpc = RISCV::OR;    break;
216     case RISCV::PseudoCCXOR:   NewOpc = RISCV::XOR;   break;
217     case RISCV::PseudoCCADDI:  NewOpc = RISCV::ADDI;  break;
218     case RISCV::PseudoCCSLLI:  NewOpc = RISCV::SLLI;  break;
219     case RISCV::PseudoCCSRLI:  NewOpc = RISCV::SRLI;  break;
220     case RISCV::PseudoCCSRAI:  NewOpc = RISCV::SRAI;  break;
221     case RISCV::PseudoCCANDI:  NewOpc = RISCV::ANDI;  break;
222     case RISCV::PseudoCCORI:   NewOpc = RISCV::ORI;   break;
223     case RISCV::PseudoCCXORI:  NewOpc = RISCV::XORI;  break;
224     case RISCV::PseudoCCADDW:  NewOpc = RISCV::ADDW;  break;
225     case RISCV::PseudoCCSUBW:  NewOpc = RISCV::SUBW;  break;
226     case RISCV::PseudoCCSLLW:  NewOpc = RISCV::SLLW;  break;
227     case RISCV::PseudoCCSRLW:  NewOpc = RISCV::SRLW;  break;
228     case RISCV::PseudoCCSRAW:  NewOpc = RISCV::SRAW;  break;
229     case RISCV::PseudoCCADDIW: NewOpc = RISCV::ADDIW; break;
230     case RISCV::PseudoCCSLLIW: NewOpc = RISCV::SLLIW; break;
231     case RISCV::PseudoCCSRLIW: NewOpc = RISCV::SRLIW; break;
232     case RISCV::PseudoCCSRAIW: NewOpc = RISCV::SRAIW; break;
233     case RISCV::PseudoCCANDN:  NewOpc = RISCV::ANDN;  break;
234     case RISCV::PseudoCCORN:   NewOpc = RISCV::ORN;   break;
235     case RISCV::PseudoCCXNOR:  NewOpc = RISCV::XNOR;  break;
236     }
237     BuildMI(TrueBB, DL, TII->get(NewOpc), DestReg)
238         .add(MI.getOperand(5))
239         .add(MI.getOperand(6));
240   }
241 
242   TrueBB->addSuccessor(MergeBB);
243 
244   MergeBB->splice(MergeBB->end(), &MBB, MI, MBB.end());
245   MergeBB->transferSuccessors(&MBB);
246 
247   MBB.addSuccessor(TrueBB);
248   MBB.addSuccessor(MergeBB);
249 
250   NextMBBI = MBB.end();
251   MI.eraseFromParent();
252 
253   // Make sure live-ins are correctly attached to this new basic block.
254   LivePhysRegs LiveRegs;
255   computeAndAddLiveIns(LiveRegs, *TrueBB);
256   computeAndAddLiveIns(LiveRegs, *MergeBB);
257 
258   return true;
259 }
260 
261 bool RISCVExpandPseudo::expandVSetVL(MachineBasicBlock &MBB,
262                                      MachineBasicBlock::iterator MBBI) {
263   assert(MBBI->getNumExplicitOperands() == 3 && MBBI->getNumOperands() >= 5 &&
264          "Unexpected instruction format");
265 
266   DebugLoc DL = MBBI->getDebugLoc();
267 
268   assert((MBBI->getOpcode() == RISCV::PseudoVSETVLI ||
269           MBBI->getOpcode() == RISCV::PseudoVSETVLIX0 ||
270           MBBI->getOpcode() == RISCV::PseudoVSETIVLI) &&
271          "Unexpected pseudo instruction");
272   unsigned Opcode;
273   if (MBBI->getOpcode() == RISCV::PseudoVSETIVLI)
274     Opcode = RISCV::VSETIVLI;
275   else
276     Opcode = RISCV::VSETVLI;
277   const MCInstrDesc &Desc = TII->get(Opcode);
278   assert(Desc.getNumOperands() == 3 && "Unexpected instruction format");
279 
280   Register DstReg = MBBI->getOperand(0).getReg();
281   bool DstIsDead = MBBI->getOperand(0).isDead();
282   BuildMI(MBB, MBBI, DL, Desc)
283       .addReg(DstReg, RegState::Define | getDeadRegState(DstIsDead))
284       .add(MBBI->getOperand(1))  // VL
285       .add(MBBI->getOperand(2)); // VType
286 
287   MBBI->eraseFromParent(); // The pseudo instruction is gone now.
288   return true;
289 }
290 
291 bool RISCVExpandPseudo::expandVMSET_VMCLR(MachineBasicBlock &MBB,
292                                           MachineBasicBlock::iterator MBBI,
293                                           unsigned Opcode) {
294   DebugLoc DL = MBBI->getDebugLoc();
295   Register DstReg = MBBI->getOperand(0).getReg();
296   const MCInstrDesc &Desc = TII->get(Opcode);
297   BuildMI(MBB, MBBI, DL, Desc, DstReg)
298       .addReg(DstReg, RegState::Undef)
299       .addReg(DstReg, RegState::Undef);
300   MBBI->eraseFromParent(); // The pseudo instruction is gone now.
301   return true;
302 }
303 
304 // This function expands the PseudoRV32ZdinxSD for storing a double-precision
305 // floating-point value into memory by generating an equivalent instruction
306 // sequence for RV32.
307 bool RISCVExpandPseudo::expandRV32ZdinxStore(MachineBasicBlock &MBB,
308                                              MachineBasicBlock::iterator MBBI) {
309   DebugLoc DL = MBBI->getDebugLoc();
310   const TargetRegisterInfo *TRI = STI->getRegisterInfo();
311   Register Lo =
312       TRI->getSubReg(MBBI->getOperand(0).getReg(), RISCV::sub_gpr_even);
313   Register Hi =
314       TRI->getSubReg(MBBI->getOperand(0).getReg(), RISCV::sub_gpr_odd);
315   BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
316       .addReg(Lo, getKillRegState(MBBI->getOperand(0).isKill()))
317       .addReg(MBBI->getOperand(1).getReg())
318       .add(MBBI->getOperand(2));
319   if (MBBI->getOperand(2).isGlobal() || MBBI->getOperand(2).isCPI()) {
320     // FIXME: Zdinx RV32 can not work on unaligned memory.
321     assert(!STI->hasFastUnalignedAccess());
322 
323     assert(MBBI->getOperand(2).getOffset() % 8 == 0);
324     MBBI->getOperand(2).setOffset(MBBI->getOperand(2).getOffset() + 4);
325     BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
326         .addReg(Hi, getKillRegState(MBBI->getOperand(0).isKill()))
327         .add(MBBI->getOperand(1))
328         .add(MBBI->getOperand(2));
329   } else {
330     assert(isInt<12>(MBBI->getOperand(2).getImm() + 4));
331     BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
332         .addReg(Hi, getKillRegState(MBBI->getOperand(0).isKill()))
333         .add(MBBI->getOperand(1))
334         .addImm(MBBI->getOperand(2).getImm() + 4);
335   }
336   MBBI->eraseFromParent();
337   return true;
338 }
339 
340 // This function expands PseudoRV32ZdinxLoad for loading a double-precision
341 // floating-point value from memory into an equivalent instruction sequence for
342 // RV32.
343 bool RISCVExpandPseudo::expandRV32ZdinxLoad(MachineBasicBlock &MBB,
344                                             MachineBasicBlock::iterator MBBI) {
345   DebugLoc DL = MBBI->getDebugLoc();
346   const TargetRegisterInfo *TRI = STI->getRegisterInfo();
347   Register Lo =
348       TRI->getSubReg(MBBI->getOperand(0).getReg(), RISCV::sub_gpr_even);
349   Register Hi =
350       TRI->getSubReg(MBBI->getOperand(0).getReg(), RISCV::sub_gpr_odd);
351 
352   // If the register of operand 1 is equal to the Lo register, then swap the
353   // order of loading the Lo and Hi statements.
354   bool IsOp1EqualToLo = Lo == MBBI->getOperand(1).getReg();
355   // Order: Lo, Hi
356   if (!IsOp1EqualToLo) {
357     BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Lo)
358         .addReg(MBBI->getOperand(1).getReg())
359         .add(MBBI->getOperand(2));
360   }
361 
362   if (MBBI->getOperand(2).isGlobal() || MBBI->getOperand(2).isCPI()) {
363     auto Offset = MBBI->getOperand(2).getOffset();
364     assert(MBBI->getOperand(2).getOffset() % 8 == 0);
365     MBBI->getOperand(2).setOffset(Offset + 4);
366     BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Hi)
367         .addReg(MBBI->getOperand(1).getReg())
368         .add(MBBI->getOperand(2));
369     MBBI->getOperand(2).setOffset(Offset);
370   } else {
371     assert(isInt<12>(MBBI->getOperand(2).getImm() + 4));
372     BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Hi)
373         .addReg(MBBI->getOperand(1).getReg())
374         .addImm(MBBI->getOperand(2).getImm() + 4);
375   }
376 
377   // Order: Hi, Lo
378   if (IsOp1EqualToLo) {
379     BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Lo)
380         .addReg(MBBI->getOperand(1).getReg())
381         .add(MBBI->getOperand(2));
382   }
383 
384   MBBI->eraseFromParent();
385   return true;
386 }
387 
388 class RISCVPreRAExpandPseudo : public MachineFunctionPass {
389 public:
390   const RISCVSubtarget *STI;
391   const RISCVInstrInfo *TII;
392   static char ID;
393 
394   RISCVPreRAExpandPseudo() : MachineFunctionPass(ID) {}
395 
396   bool runOnMachineFunction(MachineFunction &MF) override;
397 
398   void getAnalysisUsage(AnalysisUsage &AU) const override {
399     AU.setPreservesCFG();
400     MachineFunctionPass::getAnalysisUsage(AU);
401   }
402   StringRef getPassName() const override {
403     return RISCV_PRERA_EXPAND_PSEUDO_NAME;
404   }
405 
406 private:
407   bool expandMBB(MachineBasicBlock &MBB);
408   bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
409                 MachineBasicBlock::iterator &NextMBBI);
410   bool expandAuipcInstPair(MachineBasicBlock &MBB,
411                            MachineBasicBlock::iterator MBBI,
412                            MachineBasicBlock::iterator &NextMBBI,
413                            unsigned FlagsHi, unsigned SecondOpcode);
414   bool expandLoadLocalAddress(MachineBasicBlock &MBB,
415                               MachineBasicBlock::iterator MBBI,
416                               MachineBasicBlock::iterator &NextMBBI);
417   bool expandLoadGlobalAddress(MachineBasicBlock &MBB,
418                                MachineBasicBlock::iterator MBBI,
419                                MachineBasicBlock::iterator &NextMBBI);
420   bool expandLoadTLSIEAddress(MachineBasicBlock &MBB,
421                               MachineBasicBlock::iterator MBBI,
422                               MachineBasicBlock::iterator &NextMBBI);
423   bool expandLoadTLSGDAddress(MachineBasicBlock &MBB,
424                               MachineBasicBlock::iterator MBBI,
425                               MachineBasicBlock::iterator &NextMBBI);
426   bool expandLoadTLSDescAddress(MachineBasicBlock &MBB,
427                                 MachineBasicBlock::iterator MBBI,
428                                 MachineBasicBlock::iterator &NextMBBI);
429 
430 #ifndef NDEBUG
431   unsigned getInstSizeInBytes(const MachineFunction &MF) const {
432     unsigned Size = 0;
433     for (auto &MBB : MF)
434       for (auto &MI : MBB)
435         Size += TII->getInstSizeInBytes(MI);
436     return Size;
437   }
438 #endif
439 };
440 
441 char RISCVPreRAExpandPseudo::ID = 0;
442 
443 bool RISCVPreRAExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
444   STI = &MF.getSubtarget<RISCVSubtarget>();
445   TII = STI->getInstrInfo();
446 
447 #ifndef NDEBUG
448   const unsigned OldSize = getInstSizeInBytes(MF);
449 #endif
450 
451   bool Modified = false;
452   for (auto &MBB : MF)
453     Modified |= expandMBB(MBB);
454 
455 #ifndef NDEBUG
456   const unsigned NewSize = getInstSizeInBytes(MF);
457   assert(OldSize >= NewSize);
458 #endif
459   return Modified;
460 }
461 
462 bool RISCVPreRAExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
463   bool Modified = false;
464 
465   MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
466   while (MBBI != E) {
467     MachineBasicBlock::iterator NMBBI = std::next(MBBI);
468     Modified |= expandMI(MBB, MBBI, NMBBI);
469     MBBI = NMBBI;
470   }
471 
472   return Modified;
473 }
474 
475 bool RISCVPreRAExpandPseudo::expandMI(MachineBasicBlock &MBB,
476                                       MachineBasicBlock::iterator MBBI,
477                                       MachineBasicBlock::iterator &NextMBBI) {
478 
479   switch (MBBI->getOpcode()) {
480   case RISCV::PseudoLLA:
481     return expandLoadLocalAddress(MBB, MBBI, NextMBBI);
482   case RISCV::PseudoLGA:
483     return expandLoadGlobalAddress(MBB, MBBI, NextMBBI);
484   case RISCV::PseudoLA_TLS_IE:
485     return expandLoadTLSIEAddress(MBB, MBBI, NextMBBI);
486   case RISCV::PseudoLA_TLS_GD:
487     return expandLoadTLSGDAddress(MBB, MBBI, NextMBBI);
488   case RISCV::PseudoLA_TLSDESC:
489     return expandLoadTLSDescAddress(MBB, MBBI, NextMBBI);
490   }
491   return false;
492 }
493 
494 bool RISCVPreRAExpandPseudo::expandAuipcInstPair(
495     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
496     MachineBasicBlock::iterator &NextMBBI, unsigned FlagsHi,
497     unsigned SecondOpcode) {
498   MachineFunction *MF = MBB.getParent();
499   MachineInstr &MI = *MBBI;
500   DebugLoc DL = MI.getDebugLoc();
501 
502   Register DestReg = MI.getOperand(0).getReg();
503   Register ScratchReg =
504       MF->getRegInfo().createVirtualRegister(&RISCV::GPRRegClass);
505 
506   MachineOperand &Symbol = MI.getOperand(1);
507   Symbol.setTargetFlags(FlagsHi);
508   MCSymbol *AUIPCSymbol = MF->getContext().createNamedTempSymbol("pcrel_hi");
509 
510   MachineInstr *MIAUIPC =
511       BuildMI(MBB, MBBI, DL, TII->get(RISCV::AUIPC), ScratchReg).add(Symbol);
512   MIAUIPC->setPreInstrSymbol(*MF, AUIPCSymbol);
513 
514   MachineInstr *SecondMI =
515       BuildMI(MBB, MBBI, DL, TII->get(SecondOpcode), DestReg)
516           .addReg(ScratchReg)
517           .addSym(AUIPCSymbol, RISCVII::MO_PCREL_LO);
518 
519   if (MI.hasOneMemOperand())
520     SecondMI->addMemOperand(*MF, *MI.memoperands_begin());
521 
522   MI.eraseFromParent();
523   return true;
524 }
525 
526 bool RISCVPreRAExpandPseudo::expandLoadLocalAddress(
527     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
528     MachineBasicBlock::iterator &NextMBBI) {
529   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_PCREL_HI,
530                              RISCV::ADDI);
531 }
532 
533 bool RISCVPreRAExpandPseudo::expandLoadGlobalAddress(
534     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
535     MachineBasicBlock::iterator &NextMBBI) {
536   unsigned SecondOpcode = STI->is64Bit() ? RISCV::LD : RISCV::LW;
537   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_GOT_HI,
538                              SecondOpcode);
539 }
540 
541 bool RISCVPreRAExpandPseudo::expandLoadTLSIEAddress(
542     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
543     MachineBasicBlock::iterator &NextMBBI) {
544   unsigned SecondOpcode = STI->is64Bit() ? RISCV::LD : RISCV::LW;
545   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GOT_HI,
546                              SecondOpcode);
547 }
548 
549 bool RISCVPreRAExpandPseudo::expandLoadTLSGDAddress(
550     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
551     MachineBasicBlock::iterator &NextMBBI) {
552   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GD_HI,
553                              RISCV::ADDI);
554 }
555 
556 bool RISCVPreRAExpandPseudo::expandLoadTLSDescAddress(
557     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
558     MachineBasicBlock::iterator &NextMBBI) {
559   MachineFunction *MF = MBB.getParent();
560   MachineInstr &MI = *MBBI;
561   DebugLoc DL = MI.getDebugLoc();
562 
563   const auto &STI = MF->getSubtarget<RISCVSubtarget>();
564   unsigned SecondOpcode = STI.is64Bit() ? RISCV::LD : RISCV::LW;
565 
566   Register FinalReg = MI.getOperand(0).getReg();
567   Register DestReg =
568       MF->getRegInfo().createVirtualRegister(&RISCV::GPRRegClass);
569   Register ScratchReg =
570       MF->getRegInfo().createVirtualRegister(&RISCV::GPRRegClass);
571 
572   MachineOperand &Symbol = MI.getOperand(1);
573   Symbol.setTargetFlags(RISCVII::MO_TLSDESC_HI);
574   MCSymbol *AUIPCSymbol = MF->getContext().createNamedTempSymbol("tlsdesc_hi");
575 
576   MachineInstr *MIAUIPC =
577       BuildMI(MBB, MBBI, DL, TII->get(RISCV::AUIPC), ScratchReg).add(Symbol);
578   MIAUIPC->setPreInstrSymbol(*MF, AUIPCSymbol);
579 
580   BuildMI(MBB, MBBI, DL, TII->get(SecondOpcode), DestReg)
581       .addReg(ScratchReg)
582       .addSym(AUIPCSymbol, RISCVII::MO_TLSDESC_LOAD_LO);
583 
584   BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADDI), RISCV::X10)
585       .addReg(ScratchReg)
586       .addSym(AUIPCSymbol, RISCVII::MO_TLSDESC_ADD_LO);
587 
588   BuildMI(MBB, MBBI, DL, TII->get(RISCV::PseudoTLSDESCCall), RISCV::X5)
589       .addReg(DestReg)
590       .addImm(0)
591       .addSym(AUIPCSymbol, RISCVII::MO_TLSDESC_CALL);
592 
593   BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADD), FinalReg)
594       .addReg(RISCV::X10)
595       .addReg(RISCV::X4);
596 
597   MI.eraseFromParent();
598   return true;
599 }
600 
601 } // end of anonymous namespace
602 
603 INITIALIZE_PASS(RISCVExpandPseudo, "riscv-expand-pseudo",
604                 RISCV_EXPAND_PSEUDO_NAME, false, false)
605 
606 INITIALIZE_PASS(RISCVPreRAExpandPseudo, "riscv-prera-expand-pseudo",
607                 RISCV_PRERA_EXPAND_PSEUDO_NAME, false, false)
608 
609 namespace llvm {
610 
611 FunctionPass *createRISCVExpandPseudoPass() { return new RISCVExpandPseudo(); }
612 FunctionPass *createRISCVPreRAExpandPseudoPass() { return new RISCVPreRAExpandPseudo(); }
613 
614 } // end of namespace llvm
615