1 //===-- MipsExpandPseudoInsts.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 to allow proper scheduling, if-conversion, and other late
11 // optimizations. This pass should be run after register allocation but before
12 // the post-regalloc scheduling pass.
13 //
14 // This is currently only used for expanding atomic pseudos after register
15 // allocation. We do this to avoid the fast register allocator introducing
16 // spills between ll and sc. These stores cause some MIPS implementations to
17 // abort the atomic RMW sequence.
18 //
19 //===----------------------------------------------------------------------===//
20
21 #include "Mips.h"
22 #include "MipsInstrInfo.h"
23 #include "MipsSubtarget.h"
24 #include "llvm/CodeGen/LivePhysRegs.h"
25 #include "llvm/CodeGen/MachineFunctionPass.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27
28 using namespace llvm;
29
30 #define DEBUG_TYPE "mips-pseudo"
31
32 namespace {
33 class MipsExpandPseudo : public MachineFunctionPass {
34 public:
35 static char ID;
MipsExpandPseudo()36 MipsExpandPseudo() : MachineFunctionPass(ID) {}
37
38 const MipsInstrInfo *TII;
39 const MipsSubtarget *STI;
40
41 bool runOnMachineFunction(MachineFunction &Fn) override;
42
getRequiredProperties() const43 MachineFunctionProperties getRequiredProperties() const override {
44 return MachineFunctionProperties().set(
45 MachineFunctionProperties::Property::NoVRegs);
46 }
47
getPassName() const48 StringRef getPassName() const override {
49 return "Mips pseudo instruction expansion pass";
50 }
51
52 private:
53 bool expandAtomicCmpSwap(MachineBasicBlock &MBB,
54 MachineBasicBlock::iterator MBBI,
55 MachineBasicBlock::iterator &NextMBBI);
56 bool expandAtomicCmpSwapSubword(MachineBasicBlock &MBB,
57 MachineBasicBlock::iterator MBBI,
58 MachineBasicBlock::iterator &NextMBBI);
59
60 bool expandAtomicBinOp(MachineBasicBlock &BB,
61 MachineBasicBlock::iterator I,
62 MachineBasicBlock::iterator &NMBBI, unsigned Size);
63 bool expandAtomicBinOpSubword(MachineBasicBlock &BB,
64 MachineBasicBlock::iterator I,
65 MachineBasicBlock::iterator &NMBBI);
66
67 bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
68 MachineBasicBlock::iterator &NMBB);
69 bool expandMBB(MachineBasicBlock &MBB);
70 };
71 char MipsExpandPseudo::ID = 0;
72 }
73
expandAtomicCmpSwapSubword(MachineBasicBlock & BB,MachineBasicBlock::iterator I,MachineBasicBlock::iterator & NMBBI)74 bool MipsExpandPseudo::expandAtomicCmpSwapSubword(
75 MachineBasicBlock &BB, MachineBasicBlock::iterator I,
76 MachineBasicBlock::iterator &NMBBI) {
77
78 MachineFunction *MF = BB.getParent();
79
80 const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
81 DebugLoc DL = I->getDebugLoc();
82 unsigned LL, SC;
83
84 unsigned ZERO = Mips::ZERO;
85 unsigned BNE = Mips::BNE;
86 unsigned BEQ = Mips::BEQ;
87 unsigned SEOp =
88 I->getOpcode() == Mips::ATOMIC_CMP_SWAP_I8_POSTRA ? Mips::SEB : Mips::SEH;
89
90 if (STI->inMicroMipsMode()) {
91 LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
92 SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
93 BNE = STI->hasMips32r6() ? Mips::BNEC_MMR6 : Mips::BNE_MM;
94 BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
95 } else {
96 LL = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
97 : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
98 SC = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
99 : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
100 }
101
102 Register Dest = I->getOperand(0).getReg();
103 Register Ptr = I->getOperand(1).getReg();
104 Register Mask = I->getOperand(2).getReg();
105 Register ShiftCmpVal = I->getOperand(3).getReg();
106 Register Mask2 = I->getOperand(4).getReg();
107 Register ShiftNewVal = I->getOperand(5).getReg();
108 Register ShiftAmnt = I->getOperand(6).getReg();
109 Register Scratch = I->getOperand(7).getReg();
110 Register Scratch2 = I->getOperand(8).getReg();
111
112 // insert new blocks after the current block
113 const BasicBlock *LLVM_BB = BB.getBasicBlock();
114 MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
115 MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
116 MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
117 MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
118 MachineFunction::iterator It = ++BB.getIterator();
119 MF->insert(It, loop1MBB);
120 MF->insert(It, loop2MBB);
121 MF->insert(It, sinkMBB);
122 MF->insert(It, exitMBB);
123
124 // Transfer the remainder of BB and its successor edges to exitMBB.
125 exitMBB->splice(exitMBB->begin(), &BB,
126 std::next(MachineBasicBlock::iterator(I)), BB.end());
127 exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
128
129 // thisMBB:
130 // ...
131 // fallthrough --> loop1MBB
132 BB.addSuccessor(loop1MBB, BranchProbability::getOne());
133 loop1MBB->addSuccessor(sinkMBB);
134 loop1MBB->addSuccessor(loop2MBB);
135 loop1MBB->normalizeSuccProbs();
136 loop2MBB->addSuccessor(loop1MBB);
137 loop2MBB->addSuccessor(sinkMBB);
138 loop2MBB->normalizeSuccProbs();
139 sinkMBB->addSuccessor(exitMBB, BranchProbability::getOne());
140
141 // loop1MBB:
142 // ll dest, 0(ptr)
143 // and Mask', dest, Mask
144 // bne Mask', ShiftCmpVal, exitMBB
145 BuildMI(loop1MBB, DL, TII->get(LL), Scratch).addReg(Ptr).addImm(0);
146 BuildMI(loop1MBB, DL, TII->get(Mips::AND), Scratch2)
147 .addReg(Scratch)
148 .addReg(Mask);
149 BuildMI(loop1MBB, DL, TII->get(BNE))
150 .addReg(Scratch2).addReg(ShiftCmpVal).addMBB(sinkMBB);
151
152 // loop2MBB:
153 // and dest, dest, mask2
154 // or dest, dest, ShiftNewVal
155 // sc dest, dest, 0(ptr)
156 // beq dest, $0, loop1MBB
157 BuildMI(loop2MBB, DL, TII->get(Mips::AND), Scratch)
158 .addReg(Scratch, RegState::Kill)
159 .addReg(Mask2);
160 BuildMI(loop2MBB, DL, TII->get(Mips::OR), Scratch)
161 .addReg(Scratch, RegState::Kill)
162 .addReg(ShiftNewVal);
163 BuildMI(loop2MBB, DL, TII->get(SC), Scratch)
164 .addReg(Scratch, RegState::Kill)
165 .addReg(Ptr)
166 .addImm(0);
167 BuildMI(loop2MBB, DL, TII->get(BEQ))
168 .addReg(Scratch, RegState::Kill)
169 .addReg(ZERO)
170 .addMBB(loop1MBB);
171
172 // sinkMBB:
173 // srl srlres, Mask', shiftamt
174 // sign_extend dest,srlres
175 BuildMI(sinkMBB, DL, TII->get(Mips::SRLV), Dest)
176 .addReg(Scratch2)
177 .addReg(ShiftAmnt);
178 if (STI->hasMips32r2()) {
179 BuildMI(sinkMBB, DL, TII->get(SEOp), Dest).addReg(Dest);
180 } else {
181 const unsigned ShiftImm =
182 I->getOpcode() == Mips::ATOMIC_CMP_SWAP_I16_POSTRA ? 16 : 24;
183 BuildMI(sinkMBB, DL, TII->get(Mips::SLL), Dest)
184 .addReg(Dest, RegState::Kill)
185 .addImm(ShiftImm);
186 BuildMI(sinkMBB, DL, TII->get(Mips::SRA), Dest)
187 .addReg(Dest, RegState::Kill)
188 .addImm(ShiftImm);
189 }
190
191 LivePhysRegs LiveRegs;
192 computeAndAddLiveIns(LiveRegs, *loop1MBB);
193 computeAndAddLiveIns(LiveRegs, *loop2MBB);
194 computeAndAddLiveIns(LiveRegs, *sinkMBB);
195 computeAndAddLiveIns(LiveRegs, *exitMBB);
196
197 NMBBI = BB.end();
198 I->eraseFromParent();
199 return true;
200 }
201
expandAtomicCmpSwap(MachineBasicBlock & BB,MachineBasicBlock::iterator I,MachineBasicBlock::iterator & NMBBI)202 bool MipsExpandPseudo::expandAtomicCmpSwap(MachineBasicBlock &BB,
203 MachineBasicBlock::iterator I,
204 MachineBasicBlock::iterator &NMBBI) {
205
206 const unsigned Size =
207 I->getOpcode() == Mips::ATOMIC_CMP_SWAP_I32_POSTRA ? 4 : 8;
208 MachineFunction *MF = BB.getParent();
209
210 const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
211 DebugLoc DL = I->getDebugLoc();
212
213 unsigned LL, SC, ZERO, BNE, BEQ, MOVE;
214
215 if (Size == 4) {
216 if (STI->inMicroMipsMode()) {
217 LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
218 SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
219 BNE = STI->hasMips32r6() ? Mips::BNEC_MMR6 : Mips::BNE_MM;
220 BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
221 } else {
222 LL = STI->hasMips32r6()
223 ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
224 : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
225 SC = STI->hasMips32r6()
226 ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
227 : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
228 BNE = Mips::BNE;
229 BEQ = Mips::BEQ;
230 }
231
232 ZERO = Mips::ZERO;
233 MOVE = Mips::OR;
234 } else {
235 LL = STI->hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
236 SC = STI->hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
237 ZERO = Mips::ZERO_64;
238 BNE = Mips::BNE64;
239 BEQ = Mips::BEQ64;
240 MOVE = Mips::OR64;
241 }
242
243 Register Dest = I->getOperand(0).getReg();
244 Register Ptr = I->getOperand(1).getReg();
245 Register OldVal = I->getOperand(2).getReg();
246 Register NewVal = I->getOperand(3).getReg();
247 Register Scratch = I->getOperand(4).getReg();
248
249 // insert new blocks after the current block
250 const BasicBlock *LLVM_BB = BB.getBasicBlock();
251 MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
252 MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
253 MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
254 MachineFunction::iterator It = ++BB.getIterator();
255 MF->insert(It, loop1MBB);
256 MF->insert(It, loop2MBB);
257 MF->insert(It, exitMBB);
258
259 // Transfer the remainder of BB and its successor edges to exitMBB.
260 exitMBB->splice(exitMBB->begin(), &BB,
261 std::next(MachineBasicBlock::iterator(I)), BB.end());
262 exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
263
264 // thisMBB:
265 // ...
266 // fallthrough --> loop1MBB
267 BB.addSuccessor(loop1MBB, BranchProbability::getOne());
268 loop1MBB->addSuccessor(exitMBB);
269 loop1MBB->addSuccessor(loop2MBB);
270 loop1MBB->normalizeSuccProbs();
271 loop2MBB->addSuccessor(loop1MBB);
272 loop2MBB->addSuccessor(exitMBB);
273 loop2MBB->normalizeSuccProbs();
274
275 // loop1MBB:
276 // ll dest, 0(ptr)
277 // bne dest, oldval, exitMBB
278 BuildMI(loop1MBB, DL, TII->get(LL), Dest).addReg(Ptr).addImm(0);
279 BuildMI(loop1MBB, DL, TII->get(BNE))
280 .addReg(Dest, RegState::Kill).addReg(OldVal).addMBB(exitMBB);
281
282 // loop2MBB:
283 // move scratch, NewVal
284 // sc Scratch, Scratch, 0(ptr)
285 // beq Scratch, $0, loop1MBB
286 BuildMI(loop2MBB, DL, TII->get(MOVE), Scratch).addReg(NewVal).addReg(ZERO);
287 BuildMI(loop2MBB, DL, TII->get(SC), Scratch)
288 .addReg(Scratch).addReg(Ptr).addImm(0);
289 BuildMI(loop2MBB, DL, TII->get(BEQ))
290 .addReg(Scratch, RegState::Kill).addReg(ZERO).addMBB(loop1MBB);
291
292 LivePhysRegs LiveRegs;
293 computeAndAddLiveIns(LiveRegs, *loop1MBB);
294 computeAndAddLiveIns(LiveRegs, *loop2MBB);
295 computeAndAddLiveIns(LiveRegs, *exitMBB);
296
297 NMBBI = BB.end();
298 I->eraseFromParent();
299 return true;
300 }
301
expandAtomicBinOpSubword(MachineBasicBlock & BB,MachineBasicBlock::iterator I,MachineBasicBlock::iterator & NMBBI)302 bool MipsExpandPseudo::expandAtomicBinOpSubword(
303 MachineBasicBlock &BB, MachineBasicBlock::iterator I,
304 MachineBasicBlock::iterator &NMBBI) {
305
306 MachineFunction *MF = BB.getParent();
307
308 const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
309 DebugLoc DL = I->getDebugLoc();
310
311 unsigned LL, SC, SLT, SLTu, OR, MOVN, MOVZ, SELNEZ, SELEQZ;
312 unsigned BEQ = Mips::BEQ;
313 unsigned SEOp = Mips::SEH;
314
315 if (STI->inMicroMipsMode()) {
316 LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
317 SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
318 BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
319 SLT = Mips::SLT_MM;
320 SLTu = Mips::SLTu_MM;
321 OR = STI->hasMips32r6() ? Mips::OR_MMR6 : Mips::OR_MM;
322 MOVN = Mips::MOVN_I_MM;
323 MOVZ = Mips::MOVZ_I_MM;
324 SELNEZ = STI->hasMips32r6() ? Mips::SELNEZ_MMR6 : Mips::SELNEZ;
325 SELEQZ = STI->hasMips32r6() ? Mips::SELEQZ_MMR6 : Mips::SELEQZ;
326 } else {
327 LL = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
328 : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
329 SC = STI->hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
330 : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
331 SLT = Mips::SLT;
332 SLTu = Mips::SLTu;
333 OR = Mips::OR;
334 MOVN = Mips::MOVN_I_I;
335 MOVZ = Mips::MOVZ_I_I;
336 SELNEZ = Mips::SELNEZ;
337 SELEQZ = Mips::SELEQZ;
338 }
339
340 bool IsSwap = false;
341 bool IsNand = false;
342 bool IsMin = false;
343 bool IsMax = false;
344 bool IsUnsigned = false;
345 bool DestOK = false;
346
347 unsigned Opcode = 0;
348 switch (I->getOpcode()) {
349 case Mips::ATOMIC_LOAD_NAND_I8_POSTRA:
350 SEOp = Mips::SEB;
351 [[fallthrough]];
352 case Mips::ATOMIC_LOAD_NAND_I16_POSTRA:
353 IsNand = true;
354 break;
355 case Mips::ATOMIC_SWAP_I8_POSTRA:
356 SEOp = Mips::SEB;
357 [[fallthrough]];
358 case Mips::ATOMIC_SWAP_I16_POSTRA:
359 IsSwap = true;
360 break;
361 case Mips::ATOMIC_LOAD_ADD_I8_POSTRA:
362 SEOp = Mips::SEB;
363 [[fallthrough]];
364 case Mips::ATOMIC_LOAD_ADD_I16_POSTRA:
365 Opcode = Mips::ADDu;
366 break;
367 case Mips::ATOMIC_LOAD_SUB_I8_POSTRA:
368 SEOp = Mips::SEB;
369 [[fallthrough]];
370 case Mips::ATOMIC_LOAD_SUB_I16_POSTRA:
371 Opcode = Mips::SUBu;
372 break;
373 case Mips::ATOMIC_LOAD_AND_I8_POSTRA:
374 SEOp = Mips::SEB;
375 [[fallthrough]];
376 case Mips::ATOMIC_LOAD_AND_I16_POSTRA:
377 Opcode = Mips::AND;
378 break;
379 case Mips::ATOMIC_LOAD_OR_I8_POSTRA:
380 SEOp = Mips::SEB;
381 [[fallthrough]];
382 case Mips::ATOMIC_LOAD_OR_I16_POSTRA:
383 Opcode = Mips::OR;
384 break;
385 case Mips::ATOMIC_LOAD_XOR_I8_POSTRA:
386 SEOp = Mips::SEB;
387 [[fallthrough]];
388 case Mips::ATOMIC_LOAD_XOR_I16_POSTRA:
389 Opcode = Mips::XOR;
390 break;
391 case Mips::ATOMIC_LOAD_UMIN_I8_POSTRA:
392 SEOp = Mips::SEB;
393 IsUnsigned = true;
394 IsMin = true;
395 break;
396 case Mips::ATOMIC_LOAD_UMIN_I16_POSTRA:
397 IsUnsigned = true;
398 IsMin = true;
399 break;
400 case Mips::ATOMIC_LOAD_MIN_I8_POSTRA:
401 SEOp = Mips::SEB;
402 IsMin = true;
403 break;
404 case Mips::ATOMIC_LOAD_MIN_I16_POSTRA:
405 IsMin = true;
406 break;
407 case Mips::ATOMIC_LOAD_UMAX_I8_POSTRA:
408 SEOp = Mips::SEB;
409 IsUnsigned = true;
410 IsMax = true;
411 break;
412 case Mips::ATOMIC_LOAD_UMAX_I16_POSTRA:
413 IsUnsigned = true;
414 IsMax = true;
415 break;
416 case Mips::ATOMIC_LOAD_MAX_I8_POSTRA:
417 SEOp = Mips::SEB;
418 IsMax = true;
419 break;
420 case Mips::ATOMIC_LOAD_MAX_I16_POSTRA:
421 IsMax = true;
422 break;
423 default:
424 llvm_unreachable("Unknown subword atomic pseudo for expansion!");
425 }
426
427 Register Dest = I->getOperand(0).getReg();
428 Register Ptr = I->getOperand(1).getReg();
429 Register Incr = I->getOperand(2).getReg();
430 Register Mask = I->getOperand(3).getReg();
431 Register Mask2 = I->getOperand(4).getReg();
432 Register ShiftAmnt = I->getOperand(5).getReg();
433 Register OldVal = I->getOperand(6).getReg();
434 Register BinOpRes = I->getOperand(7).getReg();
435 Register StoreVal = I->getOperand(8).getReg();
436
437 const BasicBlock *LLVM_BB = BB.getBasicBlock();
438 MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
439 MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
440 MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
441 MachineFunction::iterator It = ++BB.getIterator();
442 MF->insert(It, loopMBB);
443 MF->insert(It, sinkMBB);
444 MF->insert(It, exitMBB);
445
446 exitMBB->splice(exitMBB->begin(), &BB, std::next(I), BB.end());
447 exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
448
449 BB.addSuccessor(loopMBB, BranchProbability::getOne());
450 loopMBB->addSuccessor(sinkMBB);
451 loopMBB->addSuccessor(loopMBB);
452 loopMBB->normalizeSuccProbs();
453
454 BuildMI(loopMBB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
455 if (IsNand) {
456 // and andres, oldval, incr2
457 // nor binopres, $0, andres
458 // and newval, binopres, mask
459 BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
460 .addReg(OldVal)
461 .addReg(Incr);
462 BuildMI(loopMBB, DL, TII->get(Mips::NOR), BinOpRes)
463 .addReg(Mips::ZERO)
464 .addReg(BinOpRes);
465 BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
466 .addReg(BinOpRes)
467 .addReg(Mask);
468 } else if (IsMin || IsMax) {
469
470 assert(I->getNumOperands() == 10 &&
471 "Atomics min|max|umin|umax use an additional register");
472 Register Scratch4 = I->getOperand(9).getReg();
473
474 unsigned SLTScratch4 = IsUnsigned ? SLTu : SLT;
475 unsigned SELIncr = IsMax ? SELNEZ : SELEQZ;
476 unsigned SELOldVal = IsMax ? SELEQZ : SELNEZ;
477 unsigned MOVIncr = IsMax ? MOVN : MOVZ;
478
479 BuildMI(loopMBB, DL, TII->get(Mips::SRAV), StoreVal)
480 .addReg(OldVal)
481 .addReg(ShiftAmnt);
482 if (IsUnsigned) {
483 const unsigned OpMask = SEOp == Mips::SEH ? 0xffff : 0xff;
484 BuildMI(loopMBB, DL, TII->get(Mips::ANDi), StoreVal)
485 .addReg(StoreVal)
486 .addImm(OpMask);
487 } else if (STI->hasMips32r2()) {
488 BuildMI(loopMBB, DL, TII->get(SEOp), StoreVal).addReg(StoreVal);
489 } else {
490 const unsigned ShiftImm = SEOp == Mips::SEH ? 16 : 24;
491 const unsigned SROp = IsUnsigned ? Mips::SRL : Mips::SRA;
492 BuildMI(loopMBB, DL, TII->get(Mips::SLL), StoreVal)
493 .addReg(StoreVal, RegState::Kill)
494 .addImm(ShiftImm);
495 BuildMI(loopMBB, DL, TII->get(SROp), StoreVal)
496 .addReg(StoreVal, RegState::Kill)
497 .addImm(ShiftImm);
498 }
499 BuildMI(loopMBB, DL, TII->get(Mips::OR), Dest)
500 .addReg(Mips::ZERO)
501 .addReg(StoreVal);
502 DestOK = true;
503 BuildMI(loopMBB, DL, TII->get(Mips::SLLV), StoreVal)
504 .addReg(StoreVal)
505 .addReg(ShiftAmnt);
506
507 // unsigned: sltu Scratch4, StoreVal, Incr
508 // signed: slt Scratch4, StoreVal, Incr
509 BuildMI(loopMBB, DL, TII->get(SLTScratch4), Scratch4)
510 .addReg(StoreVal)
511 .addReg(Incr);
512
513 if (STI->hasMips64r6() || STI->hasMips32r6()) {
514 // max: seleqz BinOpRes, OldVal, Scratch4
515 // selnez Scratch4, Incr, Scratch4
516 // or BinOpRes, BinOpRes, Scratch4
517 // min: selnqz BinOpRes, OldVal, Scratch4
518 // seleqz Scratch4, Incr, Scratch4
519 // or BinOpRes, BinOpRes, Scratch4
520 BuildMI(loopMBB, DL, TII->get(SELOldVal), BinOpRes)
521 .addReg(StoreVal)
522 .addReg(Scratch4);
523 BuildMI(loopMBB, DL, TII->get(SELIncr), Scratch4)
524 .addReg(Incr)
525 .addReg(Scratch4);
526 BuildMI(loopMBB, DL, TII->get(OR), BinOpRes)
527 .addReg(BinOpRes)
528 .addReg(Scratch4);
529 } else {
530 // max: move BinOpRes, StoreVal
531 // movn BinOpRes, Incr, Scratch4, BinOpRes
532 // min: move BinOpRes, StoreVal
533 // movz BinOpRes, Incr, Scratch4, BinOpRes
534 BuildMI(loopMBB, DL, TII->get(OR), BinOpRes)
535 .addReg(StoreVal)
536 .addReg(Mips::ZERO);
537 BuildMI(loopMBB, DL, TII->get(MOVIncr), BinOpRes)
538 .addReg(Incr)
539 .addReg(Scratch4)
540 .addReg(BinOpRes);
541 }
542
543 // and BinOpRes, BinOpRes, Mask
544 BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
545 .addReg(BinOpRes)
546 .addReg(Mask);
547
548 } else if (!IsSwap) {
549 // <binop> binopres, oldval, incr2
550 // and newval, binopres, mask
551 BuildMI(loopMBB, DL, TII->get(Opcode), BinOpRes)
552 .addReg(OldVal)
553 .addReg(Incr);
554 BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
555 .addReg(BinOpRes)
556 .addReg(Mask);
557 } else { // atomic.swap
558 // and newval, incr2, mask
559 BuildMI(loopMBB, DL, TII->get(Mips::AND), BinOpRes)
560 .addReg(Incr)
561 .addReg(Mask);
562 }
563
564 // and StoreVal, OlddVal, Mask2
565 // or StoreVal, StoreVal, BinOpRes
566 // StoreVal<tied1> = sc StoreVal, 0(Ptr)
567 // beq StoreVal, zero, loopMBB
568 BuildMI(loopMBB, DL, TII->get(Mips::AND), StoreVal)
569 .addReg(OldVal).addReg(Mask2);
570 BuildMI(loopMBB, DL, TII->get(Mips::OR), StoreVal)
571 .addReg(StoreVal).addReg(BinOpRes);
572 BuildMI(loopMBB, DL, TII->get(SC), StoreVal)
573 .addReg(StoreVal).addReg(Ptr).addImm(0);
574 BuildMI(loopMBB, DL, TII->get(BEQ))
575 .addReg(StoreVal).addReg(Mips::ZERO).addMBB(loopMBB);
576
577 // sinkMBB:
578 // and maskedoldval1,oldval,mask
579 // srl srlres,maskedoldval1,shiftamt
580 // sign_extend dest,srlres
581
582 if (!DestOK) {
583 sinkMBB->addSuccessor(exitMBB, BranchProbability::getOne());
584 BuildMI(sinkMBB, DL, TII->get(Mips::AND), Dest).addReg(OldVal).addReg(Mask);
585 BuildMI(sinkMBB, DL, TII->get(Mips::SRLV), Dest)
586 .addReg(Dest)
587 .addReg(ShiftAmnt);
588
589 if (STI->hasMips32r2()) {
590 BuildMI(sinkMBB, DL, TII->get(SEOp), Dest).addReg(Dest);
591 } else {
592 const unsigned ShiftImm = SEOp == Mips::SEH ? 16 : 24;
593 BuildMI(sinkMBB, DL, TII->get(Mips::SLL), Dest)
594 .addReg(Dest, RegState::Kill)
595 .addImm(ShiftImm);
596 BuildMI(sinkMBB, DL, TII->get(Mips::SRA), Dest)
597 .addReg(Dest, RegState::Kill)
598 .addImm(ShiftImm);
599 }
600 }
601
602 LivePhysRegs LiveRegs;
603 computeAndAddLiveIns(LiveRegs, *loopMBB);
604 computeAndAddLiveIns(LiveRegs, *sinkMBB);
605 computeAndAddLiveIns(LiveRegs, *exitMBB);
606
607 NMBBI = BB.end();
608 I->eraseFromParent();
609
610 return true;
611 }
612
expandAtomicBinOp(MachineBasicBlock & BB,MachineBasicBlock::iterator I,MachineBasicBlock::iterator & NMBBI,unsigned Size)613 bool MipsExpandPseudo::expandAtomicBinOp(MachineBasicBlock &BB,
614 MachineBasicBlock::iterator I,
615 MachineBasicBlock::iterator &NMBBI,
616 unsigned Size) {
617 MachineFunction *MF = BB.getParent();
618
619 const bool ArePtrs64bit = STI->getABI().ArePtrs64bit();
620 DebugLoc DL = I->getDebugLoc();
621
622 unsigned LL, SC, ZERO, BEQ, SLT, SLTu, OR, MOVN, MOVZ, SELNEZ, SELEQZ;
623
624 if (Size == 4) {
625 if (STI->inMicroMipsMode()) {
626 LL = STI->hasMips32r6() ? Mips::LL_MMR6 : Mips::LL_MM;
627 SC = STI->hasMips32r6() ? Mips::SC_MMR6 : Mips::SC_MM;
628 BEQ = STI->hasMips32r6() ? Mips::BEQC_MMR6 : Mips::BEQ_MM;
629 SLT = Mips::SLT_MM;
630 SLTu = Mips::SLTu_MM;
631 OR = STI->hasMips32r6() ? Mips::OR_MMR6 : Mips::OR_MM;
632 MOVN = Mips::MOVN_I_MM;
633 MOVZ = Mips::MOVZ_I_MM;
634 SELNEZ = STI->hasMips32r6() ? Mips::SELNEZ_MMR6 : Mips::SELNEZ;
635 SELEQZ = STI->hasMips32r6() ? Mips::SELEQZ_MMR6 : Mips::SELEQZ;
636 } else {
637 LL = STI->hasMips32r6()
638 ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
639 : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
640 SC = STI->hasMips32r6()
641 ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
642 : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
643 BEQ = Mips::BEQ;
644 SLT = Mips::SLT;
645 SLTu = Mips::SLTu;
646 OR = Mips::OR;
647 MOVN = Mips::MOVN_I_I;
648 MOVZ = Mips::MOVZ_I_I;
649 SELNEZ = Mips::SELNEZ;
650 SELEQZ = Mips::SELEQZ;
651 }
652
653 ZERO = Mips::ZERO;
654 } else {
655 LL = STI->hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
656 SC = STI->hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
657 ZERO = Mips::ZERO_64;
658 BEQ = Mips::BEQ64;
659 SLT = Mips::SLT64;
660 SLTu = Mips::SLTu64;
661 OR = Mips::OR64;
662 MOVN = Mips::MOVN_I64_I64;
663 MOVZ = Mips::MOVZ_I64_I64;
664 SELNEZ = Mips::SELNEZ64;
665 SELEQZ = Mips::SELEQZ64;
666 }
667
668 Register OldVal = I->getOperand(0).getReg();
669 Register Ptr = I->getOperand(1).getReg();
670 Register Incr = I->getOperand(2).getReg();
671 Register Scratch = I->getOperand(3).getReg();
672
673 unsigned Opcode = 0;
674 unsigned AND = 0;
675 unsigned NOR = 0;
676
677 bool IsOr = false;
678 bool IsNand = false;
679 bool IsMin = false;
680 bool IsMax = false;
681 bool IsUnsigned = false;
682
683 switch (I->getOpcode()) {
684 case Mips::ATOMIC_LOAD_ADD_I32_POSTRA:
685 Opcode = Mips::ADDu;
686 break;
687 case Mips::ATOMIC_LOAD_SUB_I32_POSTRA:
688 Opcode = Mips::SUBu;
689 break;
690 case Mips::ATOMIC_LOAD_AND_I32_POSTRA:
691 Opcode = Mips::AND;
692 break;
693 case Mips::ATOMIC_LOAD_OR_I32_POSTRA:
694 Opcode = Mips::OR;
695 break;
696 case Mips::ATOMIC_LOAD_XOR_I32_POSTRA:
697 Opcode = Mips::XOR;
698 break;
699 case Mips::ATOMIC_LOAD_NAND_I32_POSTRA:
700 IsNand = true;
701 AND = Mips::AND;
702 NOR = Mips::NOR;
703 break;
704 case Mips::ATOMIC_SWAP_I32_POSTRA:
705 IsOr = true;
706 break;
707 case Mips::ATOMIC_LOAD_ADD_I64_POSTRA:
708 Opcode = Mips::DADDu;
709 break;
710 case Mips::ATOMIC_LOAD_SUB_I64_POSTRA:
711 Opcode = Mips::DSUBu;
712 break;
713 case Mips::ATOMIC_LOAD_AND_I64_POSTRA:
714 Opcode = Mips::AND64;
715 break;
716 case Mips::ATOMIC_LOAD_OR_I64_POSTRA:
717 Opcode = Mips::OR64;
718 break;
719 case Mips::ATOMIC_LOAD_XOR_I64_POSTRA:
720 Opcode = Mips::XOR64;
721 break;
722 case Mips::ATOMIC_LOAD_NAND_I64_POSTRA:
723 IsNand = true;
724 AND = Mips::AND64;
725 NOR = Mips::NOR64;
726 break;
727 case Mips::ATOMIC_SWAP_I64_POSTRA:
728 IsOr = true;
729 break;
730 case Mips::ATOMIC_LOAD_UMIN_I32_POSTRA:
731 case Mips::ATOMIC_LOAD_UMIN_I64_POSTRA:
732 IsUnsigned = true;
733 [[fallthrough]];
734 case Mips::ATOMIC_LOAD_MIN_I32_POSTRA:
735 case Mips::ATOMIC_LOAD_MIN_I64_POSTRA:
736 IsMin = true;
737 break;
738 case Mips::ATOMIC_LOAD_UMAX_I32_POSTRA:
739 case Mips::ATOMIC_LOAD_UMAX_I64_POSTRA:
740 IsUnsigned = true;
741 [[fallthrough]];
742 case Mips::ATOMIC_LOAD_MAX_I32_POSTRA:
743 case Mips::ATOMIC_LOAD_MAX_I64_POSTRA:
744 IsMax = true;
745 break;
746 default:
747 llvm_unreachable("Unknown pseudo atomic!");
748 }
749
750 const BasicBlock *LLVM_BB = BB.getBasicBlock();
751 MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
752 MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
753 MachineFunction::iterator It = ++BB.getIterator();
754 MF->insert(It, loopMBB);
755 MF->insert(It, exitMBB);
756
757 exitMBB->splice(exitMBB->begin(), &BB, std::next(I), BB.end());
758 exitMBB->transferSuccessorsAndUpdatePHIs(&BB);
759
760 BB.addSuccessor(loopMBB, BranchProbability::getOne());
761 loopMBB->addSuccessor(exitMBB);
762 loopMBB->addSuccessor(loopMBB);
763 loopMBB->normalizeSuccProbs();
764
765 BuildMI(loopMBB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
766 assert((OldVal != Ptr) && "Clobbered the wrong ptr reg!");
767 assert((OldVal != Incr) && "Clobbered the wrong reg!");
768 if (IsMin || IsMax) {
769
770 assert(I->getNumOperands() == 5 &&
771 "Atomics min|max|umin|umax use an additional register");
772 MCRegister Scratch2 = I->getOperand(4).getReg().asMCReg();
773
774 // On Mips64 result of slt is GPR32.
775 MCRegister Scratch2_32 =
776 (Size == 8) ? STI->getRegisterInfo()->getSubReg(Scratch2, Mips::sub_32)
777 : Scratch2;
778
779 unsigned SLTScratch2 = IsUnsigned ? SLTu : SLT;
780 unsigned SELIncr = IsMax ? SELNEZ : SELEQZ;
781 unsigned SELOldVal = IsMax ? SELEQZ : SELNEZ;
782 unsigned MOVIncr = IsMax ? MOVN : MOVZ;
783
784 // unsigned: sltu Scratch2, oldVal, Incr
785 // signed: slt Scratch2, oldVal, Incr
786 BuildMI(loopMBB, DL, TII->get(SLTScratch2), Scratch2_32)
787 .addReg(OldVal)
788 .addReg(Incr);
789
790 if (STI->hasMips64r6() || STI->hasMips32r6()) {
791 // max: seleqz Scratch, OldVal, Scratch2
792 // selnez Scratch2, Incr, Scratch2
793 // or Scratch, Scratch, Scratch2
794 // min: selnez Scratch, OldVal, Scratch2
795 // seleqz Scratch2, Incr, Scratch2
796 // or Scratch, Scratch, Scratch2
797 BuildMI(loopMBB, DL, TII->get(SELOldVal), Scratch)
798 .addReg(OldVal)
799 .addReg(Scratch2);
800 BuildMI(loopMBB, DL, TII->get(SELIncr), Scratch2)
801 .addReg(Incr)
802 .addReg(Scratch2);
803 BuildMI(loopMBB, DL, TII->get(OR), Scratch)
804 .addReg(Scratch)
805 .addReg(Scratch2);
806 } else {
807 // max: move Scratch, OldVal
808 // movn Scratch, Incr, Scratch2, Scratch
809 // min: move Scratch, OldVal
810 // movz Scratch, Incr, Scratch2, Scratch
811 BuildMI(loopMBB, DL, TII->get(OR), Scratch)
812 .addReg(OldVal)
813 .addReg(ZERO);
814 BuildMI(loopMBB, DL, TII->get(MOVIncr), Scratch)
815 .addReg(Incr)
816 .addReg(Scratch2)
817 .addReg(Scratch);
818 }
819
820 } else if (Opcode) {
821 BuildMI(loopMBB, DL, TII->get(Opcode), Scratch).addReg(OldVal).addReg(Incr);
822 } else if (IsNand) {
823 assert(AND && NOR &&
824 "Unknown nand instruction for atomic pseudo expansion");
825 BuildMI(loopMBB, DL, TII->get(AND), Scratch).addReg(OldVal).addReg(Incr);
826 BuildMI(loopMBB, DL, TII->get(NOR), Scratch).addReg(ZERO).addReg(Scratch);
827 } else {
828 assert(IsOr && OR && "Unknown instruction for atomic pseudo expansion!");
829 (void)IsOr;
830 BuildMI(loopMBB, DL, TII->get(OR), Scratch).addReg(Incr).addReg(ZERO);
831 }
832
833 BuildMI(loopMBB, DL, TII->get(SC), Scratch)
834 .addReg(Scratch)
835 .addReg(Ptr)
836 .addImm(0);
837 BuildMI(loopMBB, DL, TII->get(BEQ))
838 .addReg(Scratch)
839 .addReg(ZERO)
840 .addMBB(loopMBB);
841
842 NMBBI = BB.end();
843 I->eraseFromParent();
844
845 LivePhysRegs LiveRegs;
846 computeAndAddLiveIns(LiveRegs, *loopMBB);
847 computeAndAddLiveIns(LiveRegs, *exitMBB);
848
849 return true;
850 }
851
expandMI(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,MachineBasicBlock::iterator & NMBB)852 bool MipsExpandPseudo::expandMI(MachineBasicBlock &MBB,
853 MachineBasicBlock::iterator MBBI,
854 MachineBasicBlock::iterator &NMBB) {
855
856 bool Modified = false;
857
858 switch (MBBI->getOpcode()) {
859 case Mips::ATOMIC_CMP_SWAP_I32_POSTRA:
860 case Mips::ATOMIC_CMP_SWAP_I64_POSTRA:
861 return expandAtomicCmpSwap(MBB, MBBI, NMBB);
862 case Mips::ATOMIC_CMP_SWAP_I8_POSTRA:
863 case Mips::ATOMIC_CMP_SWAP_I16_POSTRA:
864 return expandAtomicCmpSwapSubword(MBB, MBBI, NMBB);
865 case Mips::ATOMIC_SWAP_I8_POSTRA:
866 case Mips::ATOMIC_SWAP_I16_POSTRA:
867 case Mips::ATOMIC_LOAD_NAND_I8_POSTRA:
868 case Mips::ATOMIC_LOAD_NAND_I16_POSTRA:
869 case Mips::ATOMIC_LOAD_ADD_I8_POSTRA:
870 case Mips::ATOMIC_LOAD_ADD_I16_POSTRA:
871 case Mips::ATOMIC_LOAD_SUB_I8_POSTRA:
872 case Mips::ATOMIC_LOAD_SUB_I16_POSTRA:
873 case Mips::ATOMIC_LOAD_AND_I8_POSTRA:
874 case Mips::ATOMIC_LOAD_AND_I16_POSTRA:
875 case Mips::ATOMIC_LOAD_OR_I8_POSTRA:
876 case Mips::ATOMIC_LOAD_OR_I16_POSTRA:
877 case Mips::ATOMIC_LOAD_XOR_I8_POSTRA:
878 case Mips::ATOMIC_LOAD_XOR_I16_POSTRA:
879 case Mips::ATOMIC_LOAD_MIN_I8_POSTRA:
880 case Mips::ATOMIC_LOAD_MIN_I16_POSTRA:
881 case Mips::ATOMIC_LOAD_MAX_I8_POSTRA:
882 case Mips::ATOMIC_LOAD_MAX_I16_POSTRA:
883 case Mips::ATOMIC_LOAD_UMIN_I8_POSTRA:
884 case Mips::ATOMIC_LOAD_UMIN_I16_POSTRA:
885 case Mips::ATOMIC_LOAD_UMAX_I8_POSTRA:
886 case Mips::ATOMIC_LOAD_UMAX_I16_POSTRA:
887 return expandAtomicBinOpSubword(MBB, MBBI, NMBB);
888 case Mips::ATOMIC_LOAD_ADD_I32_POSTRA:
889 case Mips::ATOMIC_LOAD_SUB_I32_POSTRA:
890 case Mips::ATOMIC_LOAD_AND_I32_POSTRA:
891 case Mips::ATOMIC_LOAD_OR_I32_POSTRA:
892 case Mips::ATOMIC_LOAD_XOR_I32_POSTRA:
893 case Mips::ATOMIC_LOAD_NAND_I32_POSTRA:
894 case Mips::ATOMIC_SWAP_I32_POSTRA:
895 case Mips::ATOMIC_LOAD_MIN_I32_POSTRA:
896 case Mips::ATOMIC_LOAD_MAX_I32_POSTRA:
897 case Mips::ATOMIC_LOAD_UMIN_I32_POSTRA:
898 case Mips::ATOMIC_LOAD_UMAX_I32_POSTRA:
899 return expandAtomicBinOp(MBB, MBBI, NMBB, 4);
900 case Mips::ATOMIC_LOAD_ADD_I64_POSTRA:
901 case Mips::ATOMIC_LOAD_SUB_I64_POSTRA:
902 case Mips::ATOMIC_LOAD_AND_I64_POSTRA:
903 case Mips::ATOMIC_LOAD_OR_I64_POSTRA:
904 case Mips::ATOMIC_LOAD_XOR_I64_POSTRA:
905 case Mips::ATOMIC_LOAD_NAND_I64_POSTRA:
906 case Mips::ATOMIC_SWAP_I64_POSTRA:
907 case Mips::ATOMIC_LOAD_MIN_I64_POSTRA:
908 case Mips::ATOMIC_LOAD_MAX_I64_POSTRA:
909 case Mips::ATOMIC_LOAD_UMIN_I64_POSTRA:
910 case Mips::ATOMIC_LOAD_UMAX_I64_POSTRA:
911 return expandAtomicBinOp(MBB, MBBI, NMBB, 8);
912 default:
913 return Modified;
914 }
915 }
916
expandMBB(MachineBasicBlock & MBB)917 bool MipsExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
918 bool Modified = false;
919
920 MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
921 while (MBBI != E) {
922 MachineBasicBlock::iterator NMBBI = std::next(MBBI);
923 Modified |= expandMI(MBB, MBBI, NMBBI);
924 MBBI = NMBBI;
925 }
926
927 return Modified;
928 }
929
runOnMachineFunction(MachineFunction & MF)930 bool MipsExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
931 STI = &MF.getSubtarget<MipsSubtarget>();
932 TII = STI->getInstrInfo();
933
934 bool Modified = false;
935 for (MachineBasicBlock &MBB : MF)
936 Modified |= expandMBB(MBB);
937
938 if (Modified)
939 MF.RenumberBlocks();
940
941 return Modified;
942 }
943
944 /// createMipsExpandPseudoPass - returns an instance of the pseudo instruction
945 /// expansion pass.
createMipsExpandPseudoPass()946 FunctionPass *llvm::createMipsExpandPseudoPass() {
947 return new MipsExpandPseudo();
948 }
949