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
RISCVExpandPseudo()37 RISCVExpandPseudo() : MachineFunctionPass(ID) {}
38
39 bool runOnMachineFunction(MachineFunction &MF) override;
40
getPassName() const41 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
getInstSizeInBytes(const MachineFunction & MF) const57 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
runOnMachineFunction(MachineFunction & MF)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
expandMBB(MachineBasicBlock & MBB)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
expandMI(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)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
expandCCOp(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)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
expandVSetVL(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI)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
expandVMSET_VMCLR(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,unsigned Opcode)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.
expandRV32ZdinxStore(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI)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
316 assert(MBBI->hasOneMemOperand() && "Expected mem operand");
317 MachineMemOperand *OldMMO = MBBI->memoperands().front();
318 MachineFunction *MF = MBB.getParent();
319 MachineMemOperand *MMOLo = MF->getMachineMemOperand(OldMMO, 0, 4);
320 MachineMemOperand *MMOHi = MF->getMachineMemOperand(OldMMO, 4, 4);
321
322 BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
323 .addReg(Lo, getKillRegState(MBBI->getOperand(0).isKill()))
324 .addReg(MBBI->getOperand(1).getReg())
325 .add(MBBI->getOperand(2))
326 .setMemRefs(MMOLo);
327
328 if (MBBI->getOperand(2).isGlobal() || MBBI->getOperand(2).isCPI()) {
329 // FIXME: Zdinx RV32 can not work on unaligned scalar memory.
330 assert(!STI->enableUnalignedScalarMem());
331
332 assert(MBBI->getOperand(2).getOffset() % 8 == 0);
333 MBBI->getOperand(2).setOffset(MBBI->getOperand(2).getOffset() + 4);
334 BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
335 .addReg(Hi, getKillRegState(MBBI->getOperand(0).isKill()))
336 .add(MBBI->getOperand(1))
337 .add(MBBI->getOperand(2))
338 .setMemRefs(MMOHi);
339 } else {
340 assert(isInt<12>(MBBI->getOperand(2).getImm() + 4));
341 BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
342 .addReg(Hi, getKillRegState(MBBI->getOperand(0).isKill()))
343 .add(MBBI->getOperand(1))
344 .addImm(MBBI->getOperand(2).getImm() + 4)
345 .setMemRefs(MMOHi);
346 }
347 MBBI->eraseFromParent();
348 return true;
349 }
350
351 // This function expands PseudoRV32ZdinxLoad for loading a double-precision
352 // floating-point value from memory into an equivalent instruction sequence for
353 // RV32.
expandRV32ZdinxLoad(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI)354 bool RISCVExpandPseudo::expandRV32ZdinxLoad(MachineBasicBlock &MBB,
355 MachineBasicBlock::iterator MBBI) {
356 DebugLoc DL = MBBI->getDebugLoc();
357 const TargetRegisterInfo *TRI = STI->getRegisterInfo();
358 Register Lo =
359 TRI->getSubReg(MBBI->getOperand(0).getReg(), RISCV::sub_gpr_even);
360 Register Hi =
361 TRI->getSubReg(MBBI->getOperand(0).getReg(), RISCV::sub_gpr_odd);
362
363 assert(MBBI->hasOneMemOperand() && "Expected mem operand");
364 MachineMemOperand *OldMMO = MBBI->memoperands().front();
365 MachineFunction *MF = MBB.getParent();
366 MachineMemOperand *MMOLo = MF->getMachineMemOperand(OldMMO, 0, 4);
367 MachineMemOperand *MMOHi = MF->getMachineMemOperand(OldMMO, 4, 4);
368
369 // If the register of operand 1 is equal to the Lo register, then swap the
370 // order of loading the Lo and Hi statements.
371 bool IsOp1EqualToLo = Lo == MBBI->getOperand(1).getReg();
372 // Order: Lo, Hi
373 if (!IsOp1EqualToLo) {
374 BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Lo)
375 .addReg(MBBI->getOperand(1).getReg())
376 .add(MBBI->getOperand(2))
377 .setMemRefs(MMOLo);
378 }
379
380 if (MBBI->getOperand(2).isGlobal() || MBBI->getOperand(2).isCPI()) {
381 auto Offset = MBBI->getOperand(2).getOffset();
382 assert(MBBI->getOperand(2).getOffset() % 8 == 0);
383 MBBI->getOperand(2).setOffset(Offset + 4);
384 BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Hi)
385 .addReg(MBBI->getOperand(1).getReg())
386 .add(MBBI->getOperand(2))
387 .setMemRefs(MMOHi);
388 MBBI->getOperand(2).setOffset(Offset);
389 } else {
390 assert(isInt<12>(MBBI->getOperand(2).getImm() + 4));
391 BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Hi)
392 .addReg(MBBI->getOperand(1).getReg())
393 .addImm(MBBI->getOperand(2).getImm() + 4)
394 .setMemRefs(MMOHi);
395 }
396
397 // Order: Hi, Lo
398 if (IsOp1EqualToLo) {
399 BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Lo)
400 .addReg(MBBI->getOperand(1).getReg())
401 .add(MBBI->getOperand(2))
402 .setMemRefs(MMOLo);
403 }
404
405 MBBI->eraseFromParent();
406 return true;
407 }
408
409 class RISCVPreRAExpandPseudo : public MachineFunctionPass {
410 public:
411 const RISCVSubtarget *STI;
412 const RISCVInstrInfo *TII;
413 static char ID;
414
RISCVPreRAExpandPseudo()415 RISCVPreRAExpandPseudo() : MachineFunctionPass(ID) {}
416
417 bool runOnMachineFunction(MachineFunction &MF) override;
418
getAnalysisUsage(AnalysisUsage & AU) const419 void getAnalysisUsage(AnalysisUsage &AU) const override {
420 AU.setPreservesCFG();
421 MachineFunctionPass::getAnalysisUsage(AU);
422 }
getPassName() const423 StringRef getPassName() const override {
424 return RISCV_PRERA_EXPAND_PSEUDO_NAME;
425 }
426
427 private:
428 bool expandMBB(MachineBasicBlock &MBB);
429 bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
430 MachineBasicBlock::iterator &NextMBBI);
431 bool expandAuipcInstPair(MachineBasicBlock &MBB,
432 MachineBasicBlock::iterator MBBI,
433 MachineBasicBlock::iterator &NextMBBI,
434 unsigned FlagsHi, unsigned SecondOpcode);
435 bool expandLoadLocalAddress(MachineBasicBlock &MBB,
436 MachineBasicBlock::iterator MBBI,
437 MachineBasicBlock::iterator &NextMBBI);
438 bool expandLoadGlobalAddress(MachineBasicBlock &MBB,
439 MachineBasicBlock::iterator MBBI,
440 MachineBasicBlock::iterator &NextMBBI);
441 bool expandLoadTLSIEAddress(MachineBasicBlock &MBB,
442 MachineBasicBlock::iterator MBBI,
443 MachineBasicBlock::iterator &NextMBBI);
444 bool expandLoadTLSGDAddress(MachineBasicBlock &MBB,
445 MachineBasicBlock::iterator MBBI,
446 MachineBasicBlock::iterator &NextMBBI);
447 bool expandLoadTLSDescAddress(MachineBasicBlock &MBB,
448 MachineBasicBlock::iterator MBBI,
449 MachineBasicBlock::iterator &NextMBBI);
450
451 #ifndef NDEBUG
getInstSizeInBytes(const MachineFunction & MF) const452 unsigned getInstSizeInBytes(const MachineFunction &MF) const {
453 unsigned Size = 0;
454 for (auto &MBB : MF)
455 for (auto &MI : MBB)
456 Size += TII->getInstSizeInBytes(MI);
457 return Size;
458 }
459 #endif
460 };
461
462 char RISCVPreRAExpandPseudo::ID = 0;
463
runOnMachineFunction(MachineFunction & MF)464 bool RISCVPreRAExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
465 STI = &MF.getSubtarget<RISCVSubtarget>();
466 TII = STI->getInstrInfo();
467
468 #ifndef NDEBUG
469 const unsigned OldSize = getInstSizeInBytes(MF);
470 #endif
471
472 bool Modified = false;
473 for (auto &MBB : MF)
474 Modified |= expandMBB(MBB);
475
476 #ifndef NDEBUG
477 const unsigned NewSize = getInstSizeInBytes(MF);
478 assert(OldSize >= NewSize);
479 #endif
480 return Modified;
481 }
482
expandMBB(MachineBasicBlock & MBB)483 bool RISCVPreRAExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
484 bool Modified = false;
485
486 MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
487 while (MBBI != E) {
488 MachineBasicBlock::iterator NMBBI = std::next(MBBI);
489 Modified |= expandMI(MBB, MBBI, NMBBI);
490 MBBI = NMBBI;
491 }
492
493 return Modified;
494 }
495
expandMI(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)496 bool RISCVPreRAExpandPseudo::expandMI(MachineBasicBlock &MBB,
497 MachineBasicBlock::iterator MBBI,
498 MachineBasicBlock::iterator &NextMBBI) {
499
500 switch (MBBI->getOpcode()) {
501 case RISCV::PseudoLLA:
502 return expandLoadLocalAddress(MBB, MBBI, NextMBBI);
503 case RISCV::PseudoLGA:
504 return expandLoadGlobalAddress(MBB, MBBI, NextMBBI);
505 case RISCV::PseudoLA_TLS_IE:
506 return expandLoadTLSIEAddress(MBB, MBBI, NextMBBI);
507 case RISCV::PseudoLA_TLS_GD:
508 return expandLoadTLSGDAddress(MBB, MBBI, NextMBBI);
509 case RISCV::PseudoLA_TLSDESC:
510 return expandLoadTLSDescAddress(MBB, MBBI, NextMBBI);
511 }
512 return false;
513 }
514
expandAuipcInstPair(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI,unsigned FlagsHi,unsigned SecondOpcode)515 bool RISCVPreRAExpandPseudo::expandAuipcInstPair(
516 MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
517 MachineBasicBlock::iterator &NextMBBI, unsigned FlagsHi,
518 unsigned SecondOpcode) {
519 MachineFunction *MF = MBB.getParent();
520 MachineInstr &MI = *MBBI;
521 DebugLoc DL = MI.getDebugLoc();
522
523 Register DestReg = MI.getOperand(0).getReg();
524 Register ScratchReg =
525 MF->getRegInfo().createVirtualRegister(&RISCV::GPRRegClass);
526
527 MachineOperand &Symbol = MI.getOperand(1);
528 Symbol.setTargetFlags(FlagsHi);
529 MCSymbol *AUIPCSymbol = MF->getContext().createNamedTempSymbol("pcrel_hi");
530
531 MachineInstr *MIAUIPC =
532 BuildMI(MBB, MBBI, DL, TII->get(RISCV::AUIPC), ScratchReg).add(Symbol);
533 MIAUIPC->setPreInstrSymbol(*MF, AUIPCSymbol);
534
535 MachineInstr *SecondMI =
536 BuildMI(MBB, MBBI, DL, TII->get(SecondOpcode), DestReg)
537 .addReg(ScratchReg)
538 .addSym(AUIPCSymbol, RISCVII::MO_PCREL_LO);
539
540 if (MI.hasOneMemOperand())
541 SecondMI->addMemOperand(*MF, *MI.memoperands_begin());
542
543 MI.eraseFromParent();
544 return true;
545 }
546
expandLoadLocalAddress(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)547 bool RISCVPreRAExpandPseudo::expandLoadLocalAddress(
548 MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
549 MachineBasicBlock::iterator &NextMBBI) {
550 return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_PCREL_HI,
551 RISCV::ADDI);
552 }
553
expandLoadGlobalAddress(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)554 bool RISCVPreRAExpandPseudo::expandLoadGlobalAddress(
555 MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
556 MachineBasicBlock::iterator &NextMBBI) {
557 unsigned SecondOpcode = STI->is64Bit() ? RISCV::LD : RISCV::LW;
558 return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_GOT_HI,
559 SecondOpcode);
560 }
561
expandLoadTLSIEAddress(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)562 bool RISCVPreRAExpandPseudo::expandLoadTLSIEAddress(
563 MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
564 MachineBasicBlock::iterator &NextMBBI) {
565 unsigned SecondOpcode = STI->is64Bit() ? RISCV::LD : RISCV::LW;
566 return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GOT_HI,
567 SecondOpcode);
568 }
569
expandLoadTLSGDAddress(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)570 bool RISCVPreRAExpandPseudo::expandLoadTLSGDAddress(
571 MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
572 MachineBasicBlock::iterator &NextMBBI) {
573 return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GD_HI,
574 RISCV::ADDI);
575 }
576
expandLoadTLSDescAddress(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NextMBBI)577 bool RISCVPreRAExpandPseudo::expandLoadTLSDescAddress(
578 MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
579 MachineBasicBlock::iterator &NextMBBI) {
580 MachineFunction *MF = MBB.getParent();
581 MachineInstr &MI = *MBBI;
582 DebugLoc DL = MI.getDebugLoc();
583
584 const auto &STI = MF->getSubtarget<RISCVSubtarget>();
585 unsigned SecondOpcode = STI.is64Bit() ? RISCV::LD : RISCV::LW;
586
587 Register FinalReg = MI.getOperand(0).getReg();
588 Register DestReg =
589 MF->getRegInfo().createVirtualRegister(&RISCV::GPRRegClass);
590 Register ScratchReg =
591 MF->getRegInfo().createVirtualRegister(&RISCV::GPRRegClass);
592
593 MachineOperand &Symbol = MI.getOperand(1);
594 Symbol.setTargetFlags(RISCVII::MO_TLSDESC_HI);
595 MCSymbol *AUIPCSymbol = MF->getContext().createNamedTempSymbol("tlsdesc_hi");
596
597 MachineInstr *MIAUIPC =
598 BuildMI(MBB, MBBI, DL, TII->get(RISCV::AUIPC), ScratchReg).add(Symbol);
599 MIAUIPC->setPreInstrSymbol(*MF, AUIPCSymbol);
600
601 BuildMI(MBB, MBBI, DL, TII->get(SecondOpcode), DestReg)
602 .addReg(ScratchReg)
603 .addSym(AUIPCSymbol, RISCVII::MO_TLSDESC_LOAD_LO);
604
605 BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADDI), RISCV::X10)
606 .addReg(ScratchReg)
607 .addSym(AUIPCSymbol, RISCVII::MO_TLSDESC_ADD_LO);
608
609 BuildMI(MBB, MBBI, DL, TII->get(RISCV::PseudoTLSDESCCall), RISCV::X5)
610 .addReg(DestReg)
611 .addImm(0)
612 .addSym(AUIPCSymbol, RISCVII::MO_TLSDESC_CALL);
613
614 BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADD), FinalReg)
615 .addReg(RISCV::X10)
616 .addReg(RISCV::X4);
617
618 MI.eraseFromParent();
619 return true;
620 }
621
622 } // end of anonymous namespace
623
624 INITIALIZE_PASS(RISCVExpandPseudo, "riscv-expand-pseudo",
625 RISCV_EXPAND_PSEUDO_NAME, false, false)
626
627 INITIALIZE_PASS(RISCVPreRAExpandPseudo, "riscv-prera-expand-pseudo",
628 RISCV_PRERA_EXPAND_PSEUDO_NAME, false, false)
629
630 namespace llvm {
631
createRISCVExpandPseudoPass()632 FunctionPass *createRISCVExpandPseudoPass() { return new RISCVExpandPseudo(); }
createRISCVPreRAExpandPseudoPass()633 FunctionPass *createRISCVPreRAExpandPseudoPass() { return new RISCVPreRAExpandPseudo(); }
634
635 } // end of namespace llvm
636