1 //===- HexagonSplitDouble.cpp ---------------------------------------------===//
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 #include "HexagonInstrInfo.h"
10 #include "HexagonRegisterInfo.h"
11 #include "HexagonSubtarget.h"
12 #include "llvm/ADT/BitVector.h"
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/ADT/SmallVector.h"
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/CodeGen/MachineBasicBlock.h"
17 #include "llvm/CodeGen/MachineFunction.h"
18 #include "llvm/CodeGen/MachineFunctionPass.h"
19 #include "llvm/CodeGen/MachineInstr.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/CodeGen/MachineLoopInfo.h"
22 #include "llvm/CodeGen/MachineMemOperand.h"
23 #include "llvm/CodeGen/MachineOperand.h"
24 #include "llvm/CodeGen/MachineRegisterInfo.h"
25 #include "llvm/CodeGen/TargetRegisterInfo.h"
26 #include "llvm/Config/llvm-config.h"
27 #include "llvm/IR/DebugLoc.h"
28 #include "llvm/Pass.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/Compiler.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include <algorithm>
35 #include <cassert>
36 #include <cstdint>
37 #include <limits>
38 #include <map>
39 #include <set>
40 #include <utility>
41 #include <vector>
42
43 #define DEBUG_TYPE "hsdr"
44
45 using namespace llvm;
46
47 namespace llvm {
48
49 FunctionPass *createHexagonSplitDoubleRegs();
50 void initializeHexagonSplitDoubleRegsPass(PassRegistry&);
51
52 } // end namespace llvm
53
54 static cl::opt<int> MaxHSDR("max-hsdr", cl::Hidden, cl::init(-1),
55 cl::desc("Maximum number of split partitions"));
56 static cl::opt<bool> MemRefsFixed("hsdr-no-mem", cl::Hidden, cl::init(true),
57 cl::desc("Do not split loads or stores"));
58 static cl::opt<bool> SplitAll("hsdr-split-all", cl::Hidden, cl::init(false),
59 cl::desc("Split all partitions"));
60
61 namespace {
62
63 class HexagonSplitDoubleRegs : public MachineFunctionPass {
64 public:
65 static char ID;
66
HexagonSplitDoubleRegs()67 HexagonSplitDoubleRegs() : MachineFunctionPass(ID) {}
68
getPassName() const69 StringRef getPassName() const override {
70 return "Hexagon Split Double Registers";
71 }
72
getAnalysisUsage(AnalysisUsage & AU) const73 void getAnalysisUsage(AnalysisUsage &AU) const override {
74 AU.addRequired<MachineLoopInfoWrapperPass>();
75 AU.addPreserved<MachineLoopInfoWrapperPass>();
76 MachineFunctionPass::getAnalysisUsage(AU);
77 }
78
79 bool runOnMachineFunction(MachineFunction &MF) override;
80
81 private:
82 static const TargetRegisterClass *const DoubleRC;
83
84 const HexagonRegisterInfo *TRI = nullptr;
85 const HexagonInstrInfo *TII = nullptr;
86 const MachineLoopInfo *MLI;
87 MachineRegisterInfo *MRI;
88
89 using USet = std::set<unsigned>;
90 using UUSetMap = std::map<unsigned, USet>;
91 using UUPair = std::pair<unsigned, unsigned>;
92 using UUPairMap = std::map<unsigned, UUPair>;
93 using LoopRegMap = std::map<const MachineLoop *, USet>;
94
95 bool isInduction(unsigned Reg, LoopRegMap &IRM) const;
96 bool isVolatileInstr(const MachineInstr *MI) const;
97 bool isFixedInstr(const MachineInstr *MI) const;
98 void partitionRegisters(UUSetMap &P2Rs);
99 int32_t profit(const MachineInstr *MI) const;
100 int32_t profit(Register Reg) const;
101 bool isProfitable(const USet &Part, LoopRegMap &IRM) const;
102
103 void collectIndRegsForLoop(const MachineLoop *L, USet &Rs);
104 void collectIndRegs(LoopRegMap &IRM);
105
106 void createHalfInstr(unsigned Opc, MachineInstr *MI,
107 const UUPairMap &PairMap, unsigned SubR);
108 void splitMemRef(MachineInstr *MI, const UUPairMap &PairMap);
109 void splitImmediate(MachineInstr *MI, const UUPairMap &PairMap);
110 void splitCombine(MachineInstr *MI, const UUPairMap &PairMap);
111 void splitExt(MachineInstr *MI, const UUPairMap &PairMap);
112 void splitShift(MachineInstr *MI, const UUPairMap &PairMap);
113 void splitAslOr(MachineInstr *MI, const UUPairMap &PairMap);
114 bool splitInstr(MachineInstr *MI, const UUPairMap &PairMap);
115 void replaceSubregUses(MachineInstr *MI, const UUPairMap &PairMap);
116 void collapseRegPairs(MachineInstr *MI, const UUPairMap &PairMap);
117 bool splitPartition(const USet &Part);
118
119 static int Counter;
120
121 static void dump_partition(raw_ostream&, const USet&,
122 const TargetRegisterInfo&);
123 };
124
125 } // end anonymous namespace
126
127 char HexagonSplitDoubleRegs::ID;
128 int HexagonSplitDoubleRegs::Counter = 0;
129 const TargetRegisterClass *const HexagonSplitDoubleRegs::DoubleRC =
130 &Hexagon::DoubleRegsRegClass;
131
132 INITIALIZE_PASS(HexagonSplitDoubleRegs, "hexagon-split-double",
133 "Hexagon Split Double Registers", false, false)
134
135 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump_partition(raw_ostream & os,const USet & Part,const TargetRegisterInfo & TRI)136 LLVM_DUMP_METHOD void HexagonSplitDoubleRegs::dump_partition(raw_ostream &os,
137 const USet &Part, const TargetRegisterInfo &TRI) {
138 dbgs() << '{';
139 for (auto I : Part)
140 dbgs() << ' ' << printReg(I, &TRI);
141 dbgs() << " }";
142 }
143 #endif
144
isInduction(unsigned Reg,LoopRegMap & IRM) const145 bool HexagonSplitDoubleRegs::isInduction(unsigned Reg, LoopRegMap &IRM) const {
146 for (auto I : IRM) {
147 const USet &Rs = I.second;
148 if (Rs.find(Reg) != Rs.end())
149 return true;
150 }
151 return false;
152 }
153
isVolatileInstr(const MachineInstr * MI) const154 bool HexagonSplitDoubleRegs::isVolatileInstr(const MachineInstr *MI) const {
155 for (auto &MO : MI->memoperands())
156 if (MO->isVolatile() || MO->isAtomic())
157 return true;
158 return false;
159 }
160
isFixedInstr(const MachineInstr * MI) const161 bool HexagonSplitDoubleRegs::isFixedInstr(const MachineInstr *MI) const {
162 if (MI->mayLoadOrStore())
163 if (MemRefsFixed || isVolatileInstr(MI))
164 return true;
165 if (MI->isDebugInstr())
166 return false;
167
168 unsigned Opc = MI->getOpcode();
169 switch (Opc) {
170 default:
171 return true;
172
173 case TargetOpcode::PHI:
174 case TargetOpcode::COPY:
175 break;
176
177 case Hexagon::L2_loadrd_io:
178 // Not handling stack stores (only reg-based addresses).
179 if (MI->getOperand(1).isReg())
180 break;
181 return true;
182 case Hexagon::S2_storerd_io:
183 // Not handling stack stores (only reg-based addresses).
184 if (MI->getOperand(0).isReg())
185 break;
186 return true;
187 case Hexagon::L2_loadrd_pi:
188 case Hexagon::S2_storerd_pi:
189
190 case Hexagon::A2_tfrpi:
191 case Hexagon::A2_combineii:
192 case Hexagon::A4_combineir:
193 case Hexagon::A4_combineii:
194 case Hexagon::A4_combineri:
195 case Hexagon::A2_combinew:
196 case Hexagon::CONST64:
197
198 case Hexagon::A2_sxtw:
199
200 case Hexagon::A2_andp:
201 case Hexagon::A2_orp:
202 case Hexagon::A2_xorp:
203 case Hexagon::S2_asl_i_p_or:
204 case Hexagon::S2_asl_i_p:
205 case Hexagon::S2_asr_i_p:
206 case Hexagon::S2_lsr_i_p:
207 break;
208 }
209
210 for (auto &Op : MI->operands()) {
211 if (!Op.isReg())
212 continue;
213 Register R = Op.getReg();
214 if (!R.isVirtual())
215 return true;
216 }
217 return false;
218 }
219
partitionRegisters(UUSetMap & P2Rs)220 void HexagonSplitDoubleRegs::partitionRegisters(UUSetMap &P2Rs) {
221 using UUMap = std::map<unsigned, unsigned>;
222 using UVect = std::vector<unsigned>;
223
224 unsigned NumRegs = MRI->getNumVirtRegs();
225 BitVector DoubleRegs(NumRegs);
226 for (unsigned i = 0; i < NumRegs; ++i) {
227 Register R = Register::index2VirtReg(i);
228 if (MRI->getRegClass(R) == DoubleRC)
229 DoubleRegs.set(i);
230 }
231
232 BitVector FixedRegs(NumRegs);
233 for (int x = DoubleRegs.find_first(); x >= 0; x = DoubleRegs.find_next(x)) {
234 Register R = Register::index2VirtReg(x);
235 MachineInstr *DefI = MRI->getVRegDef(R);
236 // In some cases a register may exist, but never be defined or used.
237 // It should never appear anywhere, but mark it as "fixed", just to be
238 // safe.
239 if (!DefI || isFixedInstr(DefI))
240 FixedRegs.set(x);
241 }
242
243 UUSetMap AssocMap;
244 for (int x = DoubleRegs.find_first(); x >= 0; x = DoubleRegs.find_next(x)) {
245 if (FixedRegs[x])
246 continue;
247 Register R = Register::index2VirtReg(x);
248 LLVM_DEBUG(dbgs() << printReg(R, TRI) << " ~~");
249 USet &Asc = AssocMap[R];
250 for (auto U = MRI->use_nodbg_begin(R), Z = MRI->use_nodbg_end();
251 U != Z; ++U) {
252 MachineOperand &Op = *U;
253 MachineInstr *UseI = Op.getParent();
254 if (isFixedInstr(UseI))
255 continue;
256 for (MachineOperand &MO : UseI->operands()) {
257 // Skip non-registers or registers with subregisters.
258 if (&MO == &Op || !MO.isReg() || MO.getSubReg())
259 continue;
260 Register T = MO.getReg();
261 if (!T.isVirtual()) {
262 FixedRegs.set(x);
263 continue;
264 }
265 if (MRI->getRegClass(T) != DoubleRC)
266 continue;
267 unsigned u = Register::virtReg2Index(T);
268 if (FixedRegs[u])
269 continue;
270 LLVM_DEBUG(dbgs() << ' ' << printReg(T, TRI));
271 Asc.insert(T);
272 // Make it symmetric.
273 AssocMap[T].insert(R);
274 }
275 }
276 LLVM_DEBUG(dbgs() << '\n');
277 }
278
279 UUMap R2P;
280 unsigned NextP = 1;
281 USet Visited;
282 for (int x = DoubleRegs.find_first(); x >= 0; x = DoubleRegs.find_next(x)) {
283 Register R = Register::index2VirtReg(x);
284 if (Visited.count(R))
285 continue;
286 // Create a new partition for R.
287 unsigned ThisP = FixedRegs[x] ? 0 : NextP++;
288 UVect WorkQ;
289 WorkQ.push_back(R);
290 for (unsigned i = 0; i < WorkQ.size(); ++i) {
291 unsigned T = WorkQ[i];
292 if (Visited.count(T))
293 continue;
294 R2P[T] = ThisP;
295 Visited.insert(T);
296 // Add all registers associated with T.
297 USet &Asc = AssocMap[T];
298 append_range(WorkQ, Asc);
299 }
300 }
301
302 for (auto I : R2P)
303 P2Rs[I.second].insert(I.first);
304 }
305
profitImm(unsigned Imm)306 static inline int32_t profitImm(unsigned Imm) {
307 int32_t P = 0;
308 if (Imm == 0 || Imm == 0xFFFFFFFF)
309 P += 10;
310 return P;
311 }
312
profit(const MachineInstr * MI) const313 int32_t HexagonSplitDoubleRegs::profit(const MachineInstr *MI) const {
314 unsigned ImmX = 0;
315 unsigned Opc = MI->getOpcode();
316 switch (Opc) {
317 case TargetOpcode::PHI:
318 for (const auto &Op : MI->operands())
319 if (!Op.getSubReg())
320 return 0;
321 return 10;
322 case TargetOpcode::COPY:
323 if (MI->getOperand(1).getSubReg() != 0)
324 return 10;
325 return 0;
326
327 case Hexagon::L2_loadrd_io:
328 case Hexagon::S2_storerd_io:
329 return -1;
330 case Hexagon::L2_loadrd_pi:
331 case Hexagon::S2_storerd_pi:
332 return 2;
333
334 case Hexagon::A2_tfrpi:
335 case Hexagon::CONST64: {
336 uint64_t D = MI->getOperand(1).getImm();
337 unsigned Lo = D & 0xFFFFFFFFULL;
338 unsigned Hi = D >> 32;
339 return profitImm(Lo) + profitImm(Hi);
340 }
341 case Hexagon::A2_combineii:
342 case Hexagon::A4_combineii: {
343 const MachineOperand &Op1 = MI->getOperand(1);
344 const MachineOperand &Op2 = MI->getOperand(2);
345 int32_t Prof1 = Op1.isImm() ? profitImm(Op1.getImm()) : 0;
346 int32_t Prof2 = Op2.isImm() ? profitImm(Op2.getImm()) : 0;
347 return Prof1 + Prof2;
348 }
349 case Hexagon::A4_combineri:
350 ImmX++;
351 // Fall through into A4_combineir.
352 [[fallthrough]];
353 case Hexagon::A4_combineir: {
354 ImmX++;
355 const MachineOperand &OpX = MI->getOperand(ImmX);
356 if (OpX.isImm()) {
357 int64_t V = OpX.getImm();
358 if (V == 0 || V == -1)
359 return 10;
360 }
361 // Fall through into A2_combinew.
362 [[fallthrough]];
363 }
364 case Hexagon::A2_combinew:
365 return 2;
366
367 case Hexagon::A2_sxtw:
368 return 3;
369
370 case Hexagon::A2_andp:
371 case Hexagon::A2_orp:
372 case Hexagon::A2_xorp: {
373 Register Rs = MI->getOperand(1).getReg();
374 Register Rt = MI->getOperand(2).getReg();
375 return profit(Rs) + profit(Rt);
376 }
377
378 case Hexagon::S2_asl_i_p_or: {
379 unsigned S = MI->getOperand(3).getImm();
380 if (S == 0 || S == 32)
381 return 10;
382 return -1;
383 }
384 case Hexagon::S2_asl_i_p:
385 case Hexagon::S2_asr_i_p:
386 case Hexagon::S2_lsr_i_p:
387 unsigned S = MI->getOperand(2).getImm();
388 if (S == 0 || S == 32)
389 return 10;
390 if (S == 16)
391 return 5;
392 if (S == 48)
393 return 7;
394 return -10;
395 }
396
397 return 0;
398 }
399
profit(Register Reg) const400 int32_t HexagonSplitDoubleRegs::profit(Register Reg) const {
401 assert(Reg.isVirtual());
402
403 const MachineInstr *DefI = MRI->getVRegDef(Reg);
404 switch (DefI->getOpcode()) {
405 case Hexagon::A2_tfrpi:
406 case Hexagon::CONST64:
407 case Hexagon::A2_combineii:
408 case Hexagon::A4_combineii:
409 case Hexagon::A4_combineri:
410 case Hexagon::A4_combineir:
411 case Hexagon::A2_combinew:
412 return profit(DefI);
413 default:
414 break;
415 }
416 return 0;
417 }
418
isProfitable(const USet & Part,LoopRegMap & IRM) const419 bool HexagonSplitDoubleRegs::isProfitable(const USet &Part, LoopRegMap &IRM)
420 const {
421 unsigned FixedNum = 0, LoopPhiNum = 0;
422 int32_t TotalP = 0;
423
424 for (unsigned DR : Part) {
425 MachineInstr *DefI = MRI->getVRegDef(DR);
426 int32_t P = profit(DefI);
427 if (P == std::numeric_limits<int>::min())
428 return false;
429 TotalP += P;
430 // Reduce the profitability of splitting induction registers.
431 if (isInduction(DR, IRM))
432 TotalP -= 30;
433
434 for (auto U = MRI->use_nodbg_begin(DR), W = MRI->use_nodbg_end();
435 U != W; ++U) {
436 MachineInstr *UseI = U->getParent();
437 if (isFixedInstr(UseI)) {
438 FixedNum++;
439 // Calculate the cost of generating REG_SEQUENCE instructions.
440 for (auto &Op : UseI->operands()) {
441 if (Op.isReg() && Part.count(Op.getReg()))
442 if (Op.getSubReg())
443 TotalP -= 2;
444 }
445 continue;
446 }
447 // If a register from this partition is used in a fixed instruction,
448 // and there is also a register in this partition that is used in
449 // a loop phi node, then decrease the splitting profit as this can
450 // confuse the modulo scheduler.
451 if (UseI->isPHI()) {
452 const MachineBasicBlock *PB = UseI->getParent();
453 const MachineLoop *L = MLI->getLoopFor(PB);
454 if (L && L->getHeader() == PB)
455 LoopPhiNum++;
456 }
457 // Splittable instruction.
458 int32_t P = profit(UseI);
459 if (P == std::numeric_limits<int>::min())
460 return false;
461 TotalP += P;
462 }
463 }
464
465 if (FixedNum > 0 && LoopPhiNum > 0)
466 TotalP -= 20*LoopPhiNum;
467
468 LLVM_DEBUG(dbgs() << "Partition profit: " << TotalP << '\n');
469 if (SplitAll)
470 return true;
471 return TotalP > 0;
472 }
473
collectIndRegsForLoop(const MachineLoop * L,USet & Rs)474 void HexagonSplitDoubleRegs::collectIndRegsForLoop(const MachineLoop *L,
475 USet &Rs) {
476 const MachineBasicBlock *HB = L->getHeader();
477 const MachineBasicBlock *LB = L->getLoopLatch();
478 if (!HB || !LB)
479 return;
480
481 // Examine the latch branch. Expect it to be a conditional branch to
482 // the header (either "br-cond header" or "br-cond exit; br header").
483 MachineBasicBlock *TB = nullptr, *FB = nullptr;
484 MachineBasicBlock *TmpLB = const_cast<MachineBasicBlock*>(LB);
485 SmallVector<MachineOperand,2> Cond;
486 bool BadLB = TII->analyzeBranch(*TmpLB, TB, FB, Cond, false);
487 // Only analyzable conditional branches. HII::analyzeBranch will put
488 // the branch opcode as the first element of Cond, and the predicate
489 // operand as the second.
490 if (BadLB || Cond.size() != 2)
491 return;
492 // Only simple jump-conditional (with or without negation).
493 if (!TII->PredOpcodeHasJMP_c(Cond[0].getImm()))
494 return;
495 // Must go to the header.
496 if (TB != HB && FB != HB)
497 return;
498 assert(Cond[1].isReg() && "Unexpected Cond vector from analyzeBranch");
499 // Expect a predicate register.
500 Register PR = Cond[1].getReg();
501 assert(MRI->getRegClass(PR) == &Hexagon::PredRegsRegClass);
502
503 // Get the registers on which the loop controlling compare instruction
504 // depends.
505 Register CmpR1, CmpR2;
506 const MachineInstr *CmpI = MRI->getVRegDef(PR);
507 while (CmpI->getOpcode() == Hexagon::C2_not)
508 CmpI = MRI->getVRegDef(CmpI->getOperand(1).getReg());
509
510 int64_t Mask = 0, Val = 0;
511 bool OkCI = TII->analyzeCompare(*CmpI, CmpR1, CmpR2, Mask, Val);
512 if (!OkCI)
513 return;
514 // Eliminate non-double input registers.
515 if (CmpR1 && MRI->getRegClass(CmpR1) != DoubleRC)
516 CmpR1 = 0;
517 if (CmpR2 && MRI->getRegClass(CmpR2) != DoubleRC)
518 CmpR2 = 0;
519 if (!CmpR1 && !CmpR2)
520 return;
521
522 // Now examine the top of the loop: the phi nodes that could poten-
523 // tially define loop induction registers. The registers defined by
524 // such a phi node would be used in a 64-bit add, which then would
525 // be used in the loop compare instruction.
526
527 // Get the set of all double registers defined by phi nodes in the
528 // loop header.
529 using UVect = std::vector<unsigned>;
530
531 UVect DP;
532 for (auto &MI : *HB) {
533 if (!MI.isPHI())
534 break;
535 const MachineOperand &MD = MI.getOperand(0);
536 Register R = MD.getReg();
537 if (MRI->getRegClass(R) == DoubleRC)
538 DP.push_back(R);
539 }
540 if (DP.empty())
541 return;
542
543 auto NoIndOp = [this, CmpR1, CmpR2] (unsigned R) -> bool {
544 for (auto I = MRI->use_nodbg_begin(R), E = MRI->use_nodbg_end();
545 I != E; ++I) {
546 const MachineInstr *UseI = I->getParent();
547 if (UseI->getOpcode() != Hexagon::A2_addp)
548 continue;
549 // Get the output from the add. If it is one of the inputs to the
550 // loop-controlling compare instruction, then R is likely an induc-
551 // tion register.
552 Register T = UseI->getOperand(0).getReg();
553 if (T == CmpR1 || T == CmpR2)
554 return false;
555 }
556 return true;
557 };
558 UVect::iterator End = llvm::remove_if(DP, NoIndOp);
559 Rs.insert(DP.begin(), End);
560 Rs.insert(CmpR1);
561 Rs.insert(CmpR2);
562
563 LLVM_DEBUG({
564 dbgs() << "For loop at " << printMBBReference(*HB) << " ind regs: ";
565 dump_partition(dbgs(), Rs, *TRI);
566 dbgs() << '\n';
567 });
568 }
569
collectIndRegs(LoopRegMap & IRM)570 void HexagonSplitDoubleRegs::collectIndRegs(LoopRegMap &IRM) {
571 using LoopVector = std::vector<MachineLoop *>;
572
573 LoopVector WorkQ;
574
575 append_range(WorkQ, *MLI);
576 for (unsigned i = 0; i < WorkQ.size(); ++i)
577 append_range(WorkQ, *WorkQ[i]);
578
579 USet Rs;
580 for (MachineLoop *L : WorkQ) {
581 Rs.clear();
582 collectIndRegsForLoop(L, Rs);
583 if (!Rs.empty())
584 IRM.insert(std::make_pair(L, Rs));
585 }
586 }
587
createHalfInstr(unsigned Opc,MachineInstr * MI,const UUPairMap & PairMap,unsigned SubR)588 void HexagonSplitDoubleRegs::createHalfInstr(unsigned Opc, MachineInstr *MI,
589 const UUPairMap &PairMap, unsigned SubR) {
590 MachineBasicBlock &B = *MI->getParent();
591 DebugLoc DL = MI->getDebugLoc();
592 MachineInstr *NewI = BuildMI(B, MI, DL, TII->get(Opc));
593
594 for (auto &Op : MI->operands()) {
595 if (!Op.isReg()) {
596 NewI->addOperand(Op);
597 continue;
598 }
599 // For register operands, set the subregister.
600 Register R = Op.getReg();
601 unsigned SR = Op.getSubReg();
602 bool isVirtReg = R.isVirtual();
603 bool isKill = Op.isKill();
604 if (isVirtReg && MRI->getRegClass(R) == DoubleRC) {
605 isKill = false;
606 UUPairMap::const_iterator F = PairMap.find(R);
607 if (F == PairMap.end()) {
608 SR = SubR;
609 } else {
610 const UUPair &P = F->second;
611 R = (SubR == Hexagon::isub_lo) ? P.first : P.second;
612 SR = 0;
613 }
614 }
615 auto CO = MachineOperand::CreateReg(R, Op.isDef(), Op.isImplicit(), isKill,
616 Op.isDead(), Op.isUndef(), Op.isEarlyClobber(), SR, Op.isDebug(),
617 Op.isInternalRead());
618 NewI->addOperand(CO);
619 }
620 }
621
splitMemRef(MachineInstr * MI,const UUPairMap & PairMap)622 void HexagonSplitDoubleRegs::splitMemRef(MachineInstr *MI,
623 const UUPairMap &PairMap) {
624 bool Load = MI->mayLoad();
625 unsigned OrigOpc = MI->getOpcode();
626 bool PostInc = (OrigOpc == Hexagon::L2_loadrd_pi ||
627 OrigOpc == Hexagon::S2_storerd_pi);
628 MachineInstr *LowI, *HighI;
629 MachineBasicBlock &B = *MI->getParent();
630 DebugLoc DL = MI->getDebugLoc();
631
632 // Index of the base-address-register operand.
633 unsigned AdrX = PostInc ? (Load ? 2 : 1)
634 : (Load ? 1 : 0);
635 MachineOperand &AdrOp = MI->getOperand(AdrX);
636 unsigned RSA = getRegState(AdrOp);
637 MachineOperand &ValOp = Load ? MI->getOperand(0)
638 : (PostInc ? MI->getOperand(3)
639 : MI->getOperand(2));
640 UUPairMap::const_iterator F = PairMap.find(ValOp.getReg());
641 assert(F != PairMap.end());
642
643 if (Load) {
644 const UUPair &P = F->second;
645 int64_t Off = PostInc ? 0 : MI->getOperand(2).getImm();
646 LowI = BuildMI(B, MI, DL, TII->get(Hexagon::L2_loadri_io), P.first)
647 .addReg(AdrOp.getReg(), RSA & ~RegState::Kill, AdrOp.getSubReg())
648 .addImm(Off);
649 HighI = BuildMI(B, MI, DL, TII->get(Hexagon::L2_loadri_io), P.second)
650 .addReg(AdrOp.getReg(), RSA & ~RegState::Kill, AdrOp.getSubReg())
651 .addImm(Off+4);
652 } else {
653 const UUPair &P = F->second;
654 int64_t Off = PostInc ? 0 : MI->getOperand(1).getImm();
655 LowI = BuildMI(B, MI, DL, TII->get(Hexagon::S2_storeri_io))
656 .addReg(AdrOp.getReg(), RSA & ~RegState::Kill, AdrOp.getSubReg())
657 .addImm(Off)
658 .addReg(P.first);
659 HighI = BuildMI(B, MI, DL, TII->get(Hexagon::S2_storeri_io))
660 .addReg(AdrOp.getReg(), RSA & ~RegState::Kill, AdrOp.getSubReg())
661 .addImm(Off+4)
662 .addReg(P.second);
663 }
664
665 if (PostInc) {
666 // Create the increment of the address register.
667 int64_t Inc = Load ? MI->getOperand(3).getImm()
668 : MI->getOperand(2).getImm();
669 MachineOperand &UpdOp = Load ? MI->getOperand(1) : MI->getOperand(0);
670 const TargetRegisterClass *RC = MRI->getRegClass(UpdOp.getReg());
671 Register NewR = MRI->createVirtualRegister(RC);
672 assert(!UpdOp.getSubReg() && "Def operand with subreg");
673 BuildMI(B, MI, DL, TII->get(Hexagon::A2_addi), NewR)
674 .addReg(AdrOp.getReg(), RSA)
675 .addImm(Inc);
676 MRI->replaceRegWith(UpdOp.getReg(), NewR);
677 // The original instruction will be deleted later.
678 }
679
680 // Generate a new pair of memory-operands.
681 MachineFunction &MF = *B.getParent();
682 for (auto &MO : MI->memoperands()) {
683 const MachinePointerInfo &Ptr = MO->getPointerInfo();
684 MachineMemOperand::Flags F = MO->getFlags();
685 Align A = MO->getAlign();
686
687 auto *Tmp1 = MF.getMachineMemOperand(Ptr, F, 4 /*size*/, A);
688 LowI->addMemOperand(MF, Tmp1);
689 auto *Tmp2 =
690 MF.getMachineMemOperand(Ptr, F, 4 /*size*/, std::min(A, Align(4)));
691 HighI->addMemOperand(MF, Tmp2);
692 }
693 }
694
splitImmediate(MachineInstr * MI,const UUPairMap & PairMap)695 void HexagonSplitDoubleRegs::splitImmediate(MachineInstr *MI,
696 const UUPairMap &PairMap) {
697 MachineOperand &Op0 = MI->getOperand(0);
698 MachineOperand &Op1 = MI->getOperand(1);
699 assert(Op0.isReg() && Op1.isImm());
700 uint64_t V = Op1.getImm();
701
702 MachineBasicBlock &B = *MI->getParent();
703 DebugLoc DL = MI->getDebugLoc();
704 UUPairMap::const_iterator F = PairMap.find(Op0.getReg());
705 assert(F != PairMap.end());
706 const UUPair &P = F->second;
707
708 // The operand to A2_tfrsi can only have 32 significant bits. Immediate
709 // values in MachineOperand are stored as 64-bit integers, and so the
710 // value -1 may be represented either as 64-bit -1, or 4294967295. Both
711 // will have the 32 higher bits truncated in the end, but -1 will remain
712 // as -1, while the latter may appear to be a large unsigned value
713 // requiring a constant extender. The casting to int32_t will select the
714 // former representation. (The same reasoning applies to all 32-bit
715 // values.)
716 BuildMI(B, MI, DL, TII->get(Hexagon::A2_tfrsi), P.first)
717 .addImm(int32_t(V & 0xFFFFFFFFULL));
718 BuildMI(B, MI, DL, TII->get(Hexagon::A2_tfrsi), P.second)
719 .addImm(int32_t(V >> 32));
720 }
721
splitCombine(MachineInstr * MI,const UUPairMap & PairMap)722 void HexagonSplitDoubleRegs::splitCombine(MachineInstr *MI,
723 const UUPairMap &PairMap) {
724 MachineOperand &Op0 = MI->getOperand(0);
725 MachineOperand &Op1 = MI->getOperand(1);
726 MachineOperand &Op2 = MI->getOperand(2);
727 assert(Op0.isReg());
728
729 MachineBasicBlock &B = *MI->getParent();
730 DebugLoc DL = MI->getDebugLoc();
731 UUPairMap::const_iterator F = PairMap.find(Op0.getReg());
732 assert(F != PairMap.end());
733 const UUPair &P = F->second;
734
735 if (!Op1.isReg()) {
736 BuildMI(B, MI, DL, TII->get(Hexagon::A2_tfrsi), P.second)
737 .add(Op1);
738 } else {
739 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), P.second)
740 .addReg(Op1.getReg(), getRegState(Op1), Op1.getSubReg());
741 }
742
743 if (!Op2.isReg()) {
744 BuildMI(B, MI, DL, TII->get(Hexagon::A2_tfrsi), P.first)
745 .add(Op2);
746 } else {
747 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), P.first)
748 .addReg(Op2.getReg(), getRegState(Op2), Op2.getSubReg());
749 }
750 }
751
splitExt(MachineInstr * MI,const UUPairMap & PairMap)752 void HexagonSplitDoubleRegs::splitExt(MachineInstr *MI,
753 const UUPairMap &PairMap) {
754 MachineOperand &Op0 = MI->getOperand(0);
755 MachineOperand &Op1 = MI->getOperand(1);
756 assert(Op0.isReg() && Op1.isReg());
757
758 MachineBasicBlock &B = *MI->getParent();
759 DebugLoc DL = MI->getDebugLoc();
760 UUPairMap::const_iterator F = PairMap.find(Op0.getReg());
761 assert(F != PairMap.end());
762 const UUPair &P = F->second;
763 unsigned RS = getRegState(Op1);
764
765 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), P.first)
766 .addReg(Op1.getReg(), RS & ~RegState::Kill, Op1.getSubReg());
767 BuildMI(B, MI, DL, TII->get(Hexagon::S2_asr_i_r), P.second)
768 .addReg(Op1.getReg(), RS, Op1.getSubReg())
769 .addImm(31);
770 }
771
splitShift(MachineInstr * MI,const UUPairMap & PairMap)772 void HexagonSplitDoubleRegs::splitShift(MachineInstr *MI,
773 const UUPairMap &PairMap) {
774 using namespace Hexagon;
775
776 MachineOperand &Op0 = MI->getOperand(0);
777 MachineOperand &Op1 = MI->getOperand(1);
778 MachineOperand &Op2 = MI->getOperand(2);
779 assert(Op0.isReg() && Op1.isReg() && Op2.isImm());
780 int64_t Sh64 = Op2.getImm();
781 assert(Sh64 >= 0 && Sh64 < 64);
782 unsigned S = Sh64;
783
784 UUPairMap::const_iterator F = PairMap.find(Op0.getReg());
785 assert(F != PairMap.end());
786 const UUPair &P = F->second;
787 Register LoR = P.first;
788 Register HiR = P.second;
789
790 unsigned Opc = MI->getOpcode();
791 bool Right = (Opc == S2_lsr_i_p || Opc == S2_asr_i_p);
792 bool Left = !Right;
793 bool Signed = (Opc == S2_asr_i_p);
794
795 MachineBasicBlock &B = *MI->getParent();
796 DebugLoc DL = MI->getDebugLoc();
797 unsigned RS = getRegState(Op1);
798 unsigned ShiftOpc = Left ? S2_asl_i_r
799 : (Signed ? S2_asr_i_r : S2_lsr_i_r);
800 unsigned LoSR = isub_lo;
801 unsigned HiSR = isub_hi;
802
803 if (S == 0) {
804 // No shift, subregister copy.
805 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), LoR)
806 .addReg(Op1.getReg(), RS & ~RegState::Kill, LoSR);
807 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), HiR)
808 .addReg(Op1.getReg(), RS, HiSR);
809 } else if (S < 32) {
810 const TargetRegisterClass *IntRC = &IntRegsRegClass;
811 Register TmpR = MRI->createVirtualRegister(IntRC);
812 // Expansion:
813 // Shift left: DR = shl R, #s
814 // LoR = shl R.lo, #s
815 // TmpR = extractu R.lo, #s, #32-s
816 // HiR = or (TmpR, asl(R.hi, #s))
817 // Shift right: DR = shr R, #s
818 // HiR = shr R.hi, #s
819 // TmpR = shr R.lo, #s
820 // LoR = insert TmpR, R.hi, #s, #32-s
821
822 // Shift left:
823 // LoR = shl R.lo, #s
824 // Shift right:
825 // TmpR = shr R.lo, #s
826
827 // Make a special case for A2_aslh and A2_asrh (they are predicable as
828 // opposed to S2_asl_i_r/S2_asr_i_r).
829 if (S == 16 && Left)
830 BuildMI(B, MI, DL, TII->get(A2_aslh), LoR)
831 .addReg(Op1.getReg(), RS & ~RegState::Kill, LoSR);
832 else if (S == 16 && Signed)
833 BuildMI(B, MI, DL, TII->get(A2_asrh), TmpR)
834 .addReg(Op1.getReg(), RS & ~RegState::Kill, LoSR);
835 else
836 BuildMI(B, MI, DL, TII->get(ShiftOpc), (Left ? LoR : TmpR))
837 .addReg(Op1.getReg(), RS & ~RegState::Kill, LoSR)
838 .addImm(S);
839
840 if (Left) {
841 // TmpR = extractu R.lo, #s, #32-s
842 BuildMI(B, MI, DL, TII->get(S2_extractu), TmpR)
843 .addReg(Op1.getReg(), RS & ~RegState::Kill, LoSR)
844 .addImm(S)
845 .addImm(32-S);
846 // HiR = or (TmpR, asl(R.hi, #s))
847 BuildMI(B, MI, DL, TII->get(S2_asl_i_r_or), HiR)
848 .addReg(TmpR)
849 .addReg(Op1.getReg(), RS, HiSR)
850 .addImm(S);
851 } else {
852 // HiR = shr R.hi, #s
853 BuildMI(B, MI, DL, TII->get(ShiftOpc), HiR)
854 .addReg(Op1.getReg(), RS & ~RegState::Kill, HiSR)
855 .addImm(S);
856 // LoR = insert TmpR, R.hi, #s, #32-s
857 BuildMI(B, MI, DL, TII->get(S2_insert), LoR)
858 .addReg(TmpR)
859 .addReg(Op1.getReg(), RS, HiSR)
860 .addImm(S)
861 .addImm(32-S);
862 }
863 } else if (S == 32) {
864 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), (Left ? HiR : LoR))
865 .addReg(Op1.getReg(), RS & ~RegState::Kill, (Left ? LoSR : HiSR));
866 if (!Signed)
867 BuildMI(B, MI, DL, TII->get(A2_tfrsi), (Left ? LoR : HiR))
868 .addImm(0);
869 else // Must be right shift.
870 BuildMI(B, MI, DL, TII->get(S2_asr_i_r), HiR)
871 .addReg(Op1.getReg(), RS, HiSR)
872 .addImm(31);
873 } else if (S < 64) {
874 S -= 32;
875 if (S == 16 && Left)
876 BuildMI(B, MI, DL, TII->get(A2_aslh), HiR)
877 .addReg(Op1.getReg(), RS & ~RegState::Kill, LoSR);
878 else if (S == 16 && Signed)
879 BuildMI(B, MI, DL, TII->get(A2_asrh), LoR)
880 .addReg(Op1.getReg(), RS & ~RegState::Kill, HiSR);
881 else
882 BuildMI(B, MI, DL, TII->get(ShiftOpc), (Left ? HiR : LoR))
883 .addReg(Op1.getReg(), RS & ~RegState::Kill, (Left ? LoSR : HiSR))
884 .addImm(S);
885
886 if (Signed)
887 BuildMI(B, MI, DL, TII->get(S2_asr_i_r), HiR)
888 .addReg(Op1.getReg(), RS, HiSR)
889 .addImm(31);
890 else
891 BuildMI(B, MI, DL, TII->get(A2_tfrsi), (Left ? LoR : HiR))
892 .addImm(0);
893 }
894 }
895
splitAslOr(MachineInstr * MI,const UUPairMap & PairMap)896 void HexagonSplitDoubleRegs::splitAslOr(MachineInstr *MI,
897 const UUPairMap &PairMap) {
898 using namespace Hexagon;
899
900 MachineOperand &Op0 = MI->getOperand(0);
901 MachineOperand &Op1 = MI->getOperand(1);
902 MachineOperand &Op2 = MI->getOperand(2);
903 MachineOperand &Op3 = MI->getOperand(3);
904 assert(Op0.isReg() && Op1.isReg() && Op2.isReg() && Op3.isImm());
905 int64_t Sh64 = Op3.getImm();
906 assert(Sh64 >= 0 && Sh64 < 64);
907 unsigned S = Sh64;
908
909 UUPairMap::const_iterator F = PairMap.find(Op0.getReg());
910 assert(F != PairMap.end());
911 const UUPair &P = F->second;
912 unsigned LoR = P.first;
913 unsigned HiR = P.second;
914
915 MachineBasicBlock &B = *MI->getParent();
916 DebugLoc DL = MI->getDebugLoc();
917 unsigned RS1 = getRegState(Op1);
918 unsigned RS2 = getRegState(Op2);
919 const TargetRegisterClass *IntRC = &IntRegsRegClass;
920
921 unsigned LoSR = isub_lo;
922 unsigned HiSR = isub_hi;
923
924 // Op0 = S2_asl_i_p_or Op1, Op2, Op3
925 // means: Op0 = or (Op1, asl(Op2, Op3))
926
927 // Expansion of
928 // DR = or (R1, asl(R2, #s))
929 //
930 // LoR = or (R1.lo, asl(R2.lo, #s))
931 // Tmp1 = extractu R2.lo, #s, #32-s
932 // Tmp2 = or R1.hi, Tmp1
933 // HiR = or (Tmp2, asl(R2.hi, #s))
934
935 if (S == 0) {
936 // DR = or (R1, asl(R2, #0))
937 // -> or (R1, R2)
938 // i.e. LoR = or R1.lo, R2.lo
939 // HiR = or R1.hi, R2.hi
940 BuildMI(B, MI, DL, TII->get(A2_or), LoR)
941 .addReg(Op1.getReg(), RS1 & ~RegState::Kill, LoSR)
942 .addReg(Op2.getReg(), RS2 & ~RegState::Kill, LoSR);
943 BuildMI(B, MI, DL, TII->get(A2_or), HiR)
944 .addReg(Op1.getReg(), RS1, HiSR)
945 .addReg(Op2.getReg(), RS2, HiSR);
946 } else if (S < 32) {
947 BuildMI(B, MI, DL, TII->get(S2_asl_i_r_or), LoR)
948 .addReg(Op1.getReg(), RS1 & ~RegState::Kill, LoSR)
949 .addReg(Op2.getReg(), RS2 & ~RegState::Kill, LoSR)
950 .addImm(S);
951 Register TmpR1 = MRI->createVirtualRegister(IntRC);
952 BuildMI(B, MI, DL, TII->get(S2_extractu), TmpR1)
953 .addReg(Op2.getReg(), RS2 & ~RegState::Kill, LoSR)
954 .addImm(S)
955 .addImm(32-S);
956 Register TmpR2 = MRI->createVirtualRegister(IntRC);
957 BuildMI(B, MI, DL, TII->get(A2_or), TmpR2)
958 .addReg(Op1.getReg(), RS1, HiSR)
959 .addReg(TmpR1);
960 BuildMI(B, MI, DL, TII->get(S2_asl_i_r_or), HiR)
961 .addReg(TmpR2)
962 .addReg(Op2.getReg(), RS2, HiSR)
963 .addImm(S);
964 } else if (S == 32) {
965 // DR = or (R1, asl(R2, #32))
966 // -> or R1, R2.lo
967 // LoR = R1.lo
968 // HiR = or R1.hi, R2.lo
969 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), LoR)
970 .addReg(Op1.getReg(), RS1 & ~RegState::Kill, LoSR);
971 BuildMI(B, MI, DL, TII->get(A2_or), HiR)
972 .addReg(Op1.getReg(), RS1, HiSR)
973 .addReg(Op2.getReg(), RS2, LoSR);
974 } else if (S < 64) {
975 // DR = or (R1, asl(R2, #s))
976 //
977 // LoR = R1:lo
978 // HiR = or (R1:hi, asl(R2:lo, #s-32))
979 S -= 32;
980 BuildMI(B, MI, DL, TII->get(TargetOpcode::COPY), LoR)
981 .addReg(Op1.getReg(), RS1 & ~RegState::Kill, LoSR);
982 BuildMI(B, MI, DL, TII->get(S2_asl_i_r_or), HiR)
983 .addReg(Op1.getReg(), RS1, HiSR)
984 .addReg(Op2.getReg(), RS2, LoSR)
985 .addImm(S);
986 }
987 }
988
splitInstr(MachineInstr * MI,const UUPairMap & PairMap)989 bool HexagonSplitDoubleRegs::splitInstr(MachineInstr *MI,
990 const UUPairMap &PairMap) {
991 using namespace Hexagon;
992
993 LLVM_DEBUG(dbgs() << "Splitting: " << *MI);
994 bool Split = false;
995 unsigned Opc = MI->getOpcode();
996
997 switch (Opc) {
998 case TargetOpcode::PHI:
999 case TargetOpcode::COPY: {
1000 Register DstR = MI->getOperand(0).getReg();
1001 if (MRI->getRegClass(DstR) == DoubleRC) {
1002 createHalfInstr(Opc, MI, PairMap, isub_lo);
1003 createHalfInstr(Opc, MI, PairMap, isub_hi);
1004 Split = true;
1005 }
1006 break;
1007 }
1008 case A2_andp:
1009 createHalfInstr(A2_and, MI, PairMap, isub_lo);
1010 createHalfInstr(A2_and, MI, PairMap, isub_hi);
1011 Split = true;
1012 break;
1013 case A2_orp:
1014 createHalfInstr(A2_or, MI, PairMap, isub_lo);
1015 createHalfInstr(A2_or, MI, PairMap, isub_hi);
1016 Split = true;
1017 break;
1018 case A2_xorp:
1019 createHalfInstr(A2_xor, MI, PairMap, isub_lo);
1020 createHalfInstr(A2_xor, MI, PairMap, isub_hi);
1021 Split = true;
1022 break;
1023
1024 case L2_loadrd_io:
1025 case L2_loadrd_pi:
1026 case S2_storerd_io:
1027 case S2_storerd_pi:
1028 splitMemRef(MI, PairMap);
1029 Split = true;
1030 break;
1031
1032 case A2_tfrpi:
1033 case CONST64:
1034 splitImmediate(MI, PairMap);
1035 Split = true;
1036 break;
1037
1038 case A2_combineii:
1039 case A4_combineir:
1040 case A4_combineii:
1041 case A4_combineri:
1042 case A2_combinew:
1043 splitCombine(MI, PairMap);
1044 Split = true;
1045 break;
1046
1047 case A2_sxtw:
1048 splitExt(MI, PairMap);
1049 Split = true;
1050 break;
1051
1052 case S2_asl_i_p:
1053 case S2_asr_i_p:
1054 case S2_lsr_i_p:
1055 splitShift(MI, PairMap);
1056 Split = true;
1057 break;
1058
1059 case S2_asl_i_p_or:
1060 splitAslOr(MI, PairMap);
1061 Split = true;
1062 break;
1063
1064 default:
1065 llvm_unreachable("Instruction not splitable");
1066 return false;
1067 }
1068
1069 return Split;
1070 }
1071
replaceSubregUses(MachineInstr * MI,const UUPairMap & PairMap)1072 void HexagonSplitDoubleRegs::replaceSubregUses(MachineInstr *MI,
1073 const UUPairMap &PairMap) {
1074 for (auto &Op : MI->operands()) {
1075 if (!Op.isReg() || !Op.isUse() || !Op.getSubReg())
1076 continue;
1077 Register R = Op.getReg();
1078 UUPairMap::const_iterator F = PairMap.find(R);
1079 if (F == PairMap.end())
1080 continue;
1081 const UUPair &P = F->second;
1082 switch (Op.getSubReg()) {
1083 case Hexagon::isub_lo:
1084 Op.setReg(P.first);
1085 break;
1086 case Hexagon::isub_hi:
1087 Op.setReg(P.second);
1088 break;
1089 }
1090 Op.setSubReg(0);
1091 }
1092 }
1093
collapseRegPairs(MachineInstr * MI,const UUPairMap & PairMap)1094 void HexagonSplitDoubleRegs::collapseRegPairs(MachineInstr *MI,
1095 const UUPairMap &PairMap) {
1096 MachineBasicBlock &B = *MI->getParent();
1097 DebugLoc DL = MI->getDebugLoc();
1098
1099 for (auto &Op : MI->operands()) {
1100 if (!Op.isReg() || !Op.isUse())
1101 continue;
1102 Register R = Op.getReg();
1103 if (!R.isVirtual())
1104 continue;
1105 if (MRI->getRegClass(R) != DoubleRC || Op.getSubReg())
1106 continue;
1107 UUPairMap::const_iterator F = PairMap.find(R);
1108 if (F == PairMap.end())
1109 continue;
1110 const UUPair &Pr = F->second;
1111 Register NewDR = MRI->createVirtualRegister(DoubleRC);
1112 BuildMI(B, MI, DL, TII->get(TargetOpcode::REG_SEQUENCE), NewDR)
1113 .addReg(Pr.first)
1114 .addImm(Hexagon::isub_lo)
1115 .addReg(Pr.second)
1116 .addImm(Hexagon::isub_hi);
1117 Op.setReg(NewDR);
1118 }
1119 }
1120
splitPartition(const USet & Part)1121 bool HexagonSplitDoubleRegs::splitPartition(const USet &Part) {
1122 using MISet = std::set<MachineInstr *>;
1123
1124 const TargetRegisterClass *IntRC = &Hexagon::IntRegsRegClass;
1125 bool Changed = false;
1126
1127 LLVM_DEBUG(dbgs() << "Splitting partition: ";
1128 dump_partition(dbgs(), Part, *TRI); dbgs() << '\n');
1129
1130 UUPairMap PairMap;
1131
1132 MISet SplitIns;
1133 for (unsigned DR : Part) {
1134 MachineInstr *DefI = MRI->getVRegDef(DR);
1135 SplitIns.insert(DefI);
1136
1137 // Collect all instructions, including fixed ones. We won't split them,
1138 // but we need to visit them again to insert the REG_SEQUENCE instructions.
1139 for (auto U = MRI->use_nodbg_begin(DR), W = MRI->use_nodbg_end();
1140 U != W; ++U)
1141 SplitIns.insert(U->getParent());
1142
1143 Register LoR = MRI->createVirtualRegister(IntRC);
1144 Register HiR = MRI->createVirtualRegister(IntRC);
1145 LLVM_DEBUG(dbgs() << "Created mapping: " << printReg(DR, TRI) << " -> "
1146 << printReg(HiR, TRI) << ':' << printReg(LoR, TRI)
1147 << '\n');
1148 PairMap.insert(std::make_pair(DR, UUPair(LoR, HiR)));
1149 }
1150
1151 MISet Erase;
1152 for (auto *MI : SplitIns) {
1153 if (isFixedInstr(MI)) {
1154 collapseRegPairs(MI, PairMap);
1155 } else {
1156 bool Done = splitInstr(MI, PairMap);
1157 if (Done)
1158 Erase.insert(MI);
1159 Changed |= Done;
1160 }
1161 }
1162
1163 for (unsigned DR : Part) {
1164 // Before erasing "double" instructions, revisit all uses of the double
1165 // registers in this partition, and replace all uses of them with subre-
1166 // gisters, with the corresponding single registers.
1167 MISet Uses;
1168 for (auto U = MRI->use_nodbg_begin(DR), W = MRI->use_nodbg_end();
1169 U != W; ++U)
1170 Uses.insert(U->getParent());
1171 for (auto *M : Uses)
1172 replaceSubregUses(M, PairMap);
1173 }
1174
1175 for (auto *MI : Erase) {
1176 MachineBasicBlock *B = MI->getParent();
1177 B->erase(MI);
1178 }
1179
1180 return Changed;
1181 }
1182
runOnMachineFunction(MachineFunction & MF)1183 bool HexagonSplitDoubleRegs::runOnMachineFunction(MachineFunction &MF) {
1184 if (skipFunction(MF.getFunction()))
1185 return false;
1186
1187 LLVM_DEBUG(dbgs() << "Splitting double registers in function: "
1188 << MF.getName() << '\n');
1189
1190 auto &ST = MF.getSubtarget<HexagonSubtarget>();
1191 TRI = ST.getRegisterInfo();
1192 TII = ST.getInstrInfo();
1193 MRI = &MF.getRegInfo();
1194 MLI = &getAnalysis<MachineLoopInfoWrapperPass>().getLI();
1195
1196 UUSetMap P2Rs;
1197 LoopRegMap IRM;
1198
1199 collectIndRegs(IRM);
1200 partitionRegisters(P2Rs);
1201
1202 LLVM_DEBUG({
1203 dbgs() << "Register partitioning: (partition #0 is fixed)\n";
1204 for (UUSetMap::iterator I = P2Rs.begin(), E = P2Rs.end(); I != E; ++I) {
1205 dbgs() << '#' << I->first << " -> ";
1206 dump_partition(dbgs(), I->second, *TRI);
1207 dbgs() << '\n';
1208 }
1209 });
1210
1211 bool Changed = false;
1212 int Limit = MaxHSDR;
1213
1214 for (UUSetMap::iterator I = P2Rs.begin(), E = P2Rs.end(); I != E; ++I) {
1215 if (I->first == 0)
1216 continue;
1217 if (Limit >= 0 && Counter >= Limit)
1218 break;
1219 USet &Part = I->second;
1220 LLVM_DEBUG(dbgs() << "Calculating profit for partition #" << I->first
1221 << '\n');
1222 if (!isProfitable(Part, IRM))
1223 continue;
1224 Counter++;
1225 Changed |= splitPartition(Part);
1226 }
1227
1228 return Changed;
1229 }
1230
createHexagonSplitDoubleRegs()1231 FunctionPass *llvm::createHexagonSplitDoubleRegs() {
1232 return new HexagonSplitDoubleRegs();
1233 }
1234