1//===- CSEInfo.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//
10//===----------------------------------------------------------------------===//
11#include "llvm/CodeGen/GlobalISel/CSEInfo.h"
12#include "llvm/CodeGen/MachineRegisterInfo.h"
13#include "llvm/InitializePasses.h"
14#include "llvm/Support/Error.h"
15
16#define DEBUG_TYPE "cseinfo"
17
18using namespace llvm;
19char llvm::GISelCSEAnalysisWrapperPass::ID = 0;
20GISelCSEAnalysisWrapperPass::GISelCSEAnalysisWrapperPass()
21 : MachineFunctionPass(ID) {
22 initializeGISelCSEAnalysisWrapperPassPass(*PassRegistry::getPassRegistry());
23}
24INITIALIZE_PASS_BEGIN(GISelCSEAnalysisWrapperPass, DEBUG_TYPE,
25 "Analysis containing CSE Info", false, true)
26INITIALIZE_PASS_END(GISelCSEAnalysisWrapperPass, DEBUG_TYPE,
27 "Analysis containing CSE Info", false, true)
28
29/// -------- UniqueMachineInstr -------------//
30
31void UniqueMachineInstr::Profile(FoldingSetNodeID &ID) {
32 GISelInstProfileBuilder(ID, MI->getMF()->getRegInfo()).addNodeID(MI);
33}
34/// -----------------------------------------
35
36/// --------- CSEConfigFull ---------- ///
37bool CSEConfigFull::shouldCSEOpc(unsigned Opc) {
38 switch (Opc) {
39 default:
40 break;
41 case TargetOpcode::G_ADD:
42 case TargetOpcode::G_AND:
43 case TargetOpcode::G_ASHR:
44 case TargetOpcode::G_LSHR:
45 case TargetOpcode::G_MUL:
46 case TargetOpcode::G_OR:
47 case TargetOpcode::G_SHL:
48 case TargetOpcode::G_SUB:
49 case TargetOpcode::G_XOR:
50 case TargetOpcode::G_UDIV:
51 case TargetOpcode::G_SDIV:
52 case TargetOpcode::G_UREM:
53 case TargetOpcode::G_SREM:
54 case TargetOpcode::G_CONSTANT:
55 case TargetOpcode::G_FCONSTANT:
56 case TargetOpcode::G_IMPLICIT_DEF:
57 case TargetOpcode::G_ZEXT:
58 case TargetOpcode::G_SEXT:
59 case TargetOpcode::G_ANYEXT:
60 case TargetOpcode::G_UNMERGE_VALUES:
61 case TargetOpcode::G_TRUNC:
62 case TargetOpcode::G_PTR_ADD:
63 case TargetOpcode::G_EXTRACT:
64 case TargetOpcode::G_SELECT:
65 case TargetOpcode::G_BUILD_VECTOR:
66 case TargetOpcode::G_BUILD_VECTOR_TRUNC:
67 case TargetOpcode::G_SEXT_INREG:
68 case TargetOpcode::G_FADD:
69 case TargetOpcode::G_FSUB:
70 case TargetOpcode::G_FMUL:
71 case TargetOpcode::G_FDIV:
72 case TargetOpcode::G_FABS:
73 // TODO: support G_FNEG.
74 case TargetOpcode::G_FMAXNUM:
75 case TargetOpcode::G_FMINNUM:
76 case TargetOpcode::G_FMAXNUM_IEEE:
77 case TargetOpcode::G_FMINNUM_IEEE:
78 return true;
79 }
80 return false;
81}
82
83bool CSEConfigConstantOnly::shouldCSEOpc(unsigned Opc) {
84 return Opc == TargetOpcode::G_CONSTANT || Opc == TargetOpcode::G_FCONSTANT ||
85 Opc == TargetOpcode::G_IMPLICIT_DEF;
86}
87
88std::unique_ptr<CSEConfigBase>
89llvm::getStandardCSEConfigForOpt(CodeGenOptLevel Level) {
90 std::unique_ptr<CSEConfigBase> Config;
91 if (Level == CodeGenOptLevel::None)
92 Config = std::make_unique<CSEConfigConstantOnly>();
93 else
94 Config = std::make_unique<CSEConfigFull>();
95 return Config;
96}
97
98/// -----------------------------------------
99
100/// -------- GISelCSEInfo -------------//
101void GISelCSEInfo::setMF(MachineFunction &MF) {
102 this->MF = &MF;
103 this->MRI = &MF.getRegInfo();
104}
105
106GISelCSEInfo::~GISelCSEInfo() = default;
107
108bool GISelCSEInfo::isUniqueMachineInstValid(
109 const UniqueMachineInstr &UMI) const {
110 // Should we check here and assert that the instruction has been fully
111 // constructed?
112 // FIXME: Any other checks required to be done here? Remove this method if
113 // none.
114 return true;
115}
116
117void GISelCSEInfo::invalidateUniqueMachineInstr(UniqueMachineInstr *UMI) {
118 bool Removed = CSEMap.RemoveNode(N: UMI);
119 (void)Removed;
120 assert(Removed && "Invalidation called on invalid UMI");
121 // FIXME: Should UMI be deallocated/destroyed?
122}
123
124UniqueMachineInstr *GISelCSEInfo::getNodeIfExists(FoldingSetNodeID &ID,
125 MachineBasicBlock *MBB,
126 void *&InsertPos) {
127 auto *Node = CSEMap.FindNodeOrInsertPos(ID, InsertPos);
128 if (Node) {
129 if (!isUniqueMachineInstValid(UMI: *Node)) {
130 invalidateUniqueMachineInstr(UMI: Node);
131 return nullptr;
132 }
133
134 if (Node->MI->getParent() != MBB)
135 return nullptr;
136 }
137 return Node;
138}
139
140void GISelCSEInfo::insertNode(UniqueMachineInstr *UMI, void *InsertPos) {
141 handleRecordedInsts();
142 assert(UMI);
143 UniqueMachineInstr *MaybeNewNode = UMI;
144 if (InsertPos)
145 CSEMap.InsertNode(N: UMI, InsertPos);
146 else
147 MaybeNewNode = CSEMap.GetOrInsertNode(N: UMI);
148 if (MaybeNewNode != UMI) {
149 // A similar node exists in the folding set. Let's ignore this one.
150 return;
151 }
152 assert(InstrMapping.count(UMI->MI) == 0 &&
153 "This instruction should not be in the map");
154 InstrMapping[UMI->MI] = MaybeNewNode;
155}
156
157UniqueMachineInstr *GISelCSEInfo::getUniqueInstrForMI(const MachineInstr *MI) {
158 assert(shouldCSE(MI->getOpcode()) && "Trying to CSE an unsupported Node");
159 auto *Node = new (UniqueInstrAllocator) UniqueMachineInstr(MI);
160 return Node;
161}
162
163void GISelCSEInfo::insertInstr(MachineInstr *MI, void *InsertPos) {
164 assert(MI);
165 // If it exists in temporary insts, remove it.
166 TemporaryInsts.remove(I: MI);
167 auto *Node = getUniqueInstrForMI(MI);
168 insertNode(UMI: Node, InsertPos);
169}
170
171MachineInstr *GISelCSEInfo::getMachineInstrIfExists(FoldingSetNodeID &ID,
172 MachineBasicBlock *MBB,
173 void *&InsertPos) {
174 handleRecordedInsts();
175 if (auto *Inst = getNodeIfExists(ID, MBB, InsertPos)) {
176 LLVM_DEBUG(dbgs() << "CSEInfo::Found Instr " << *Inst->MI);
177 return const_cast<MachineInstr *>(Inst->MI);
178 }
179 return nullptr;
180}
181
182void GISelCSEInfo::countOpcodeHit(unsigned Opc) {
183#ifndef NDEBUG
184 ++OpcodeHitTable[Opc];
185#endif
186 // Else do nothing.
187}
188
189void GISelCSEInfo::recordNewInstruction(MachineInstr *MI) {
190 if (shouldCSE(Opc: MI->getOpcode())) {
191 TemporaryInsts.insert(I: MI);
192 LLVM_DEBUG(dbgs() << "CSEInfo::Recording new MI " << *MI);
193 }
194}
195
196void GISelCSEInfo::handleRecordedInst(MachineInstr *MI) {
197 assert(shouldCSE(MI->getOpcode()) && "Invalid instruction for CSE");
198 auto *UMI = InstrMapping.lookup(Val: MI);
199 LLVM_DEBUG(dbgs() << "CSEInfo::Handling recorded MI " << *MI);
200 if (UMI) {
201 // Invalidate this MI.
202 invalidateUniqueMachineInstr(UMI);
203 InstrMapping.erase(Val: MI);
204 }
205 /// Now insert the new instruction.
206 if (UMI) {
207 /// We'll reuse the same UniqueMachineInstr to avoid the new
208 /// allocation.
209 *UMI = UniqueMachineInstr(MI);
210 insertNode(UMI, InsertPos: nullptr);
211 } else {
212 /// This is a new instruction. Allocate a new UniqueMachineInstr and
213 /// Insert.
214 insertInstr(MI);
215 }
216}
217
218void GISelCSEInfo::handleRemoveInst(MachineInstr *MI) {
219 if (auto *UMI = InstrMapping.lookup(Val: MI)) {
220 invalidateUniqueMachineInstr(UMI);
221 InstrMapping.erase(Val: MI);
222 }
223 TemporaryInsts.remove(I: MI);
224}
225
226void GISelCSEInfo::handleRecordedInsts() {
227 if (HandlingRecordedInstrs)
228 return;
229 HandlingRecordedInstrs = true;
230 while (!TemporaryInsts.empty()) {
231 auto *MI = TemporaryInsts.pop_back_val();
232 handleRecordedInst(MI);
233 }
234 HandlingRecordedInstrs = false;
235}
236
237bool GISelCSEInfo::shouldCSE(unsigned Opc) const {
238 assert(CSEOpt.get() && "CSEConfig not set");
239 return CSEOpt->shouldCSEOpc(Opc);
240}
241
242void GISelCSEInfo::erasingInstr(MachineInstr &MI) { handleRemoveInst(MI: &MI); }
243void GISelCSEInfo::createdInstr(MachineInstr &MI) { recordNewInstruction(MI: &MI); }
244void GISelCSEInfo::changingInstr(MachineInstr &MI) {
245 // For now, perform erase, followed by insert.
246 erasingInstr(MI);
247 createdInstr(MI);
248}
249void GISelCSEInfo::changedInstr(MachineInstr &MI) { changingInstr(MI); }
250
251void GISelCSEInfo::analyze(MachineFunction &MF) {
252 setMF(MF);
253 for (auto &MBB : MF) {
254 for (MachineInstr &MI : MBB) {
255 if (!shouldCSE(Opc: MI.getOpcode()))
256 continue;
257 LLVM_DEBUG(dbgs() << "CSEInfo::Add MI: " << MI);
258 insertInstr(MI: &MI);
259 }
260 }
261}
262
263void GISelCSEInfo::releaseMemory() {
264 print();
265 CSEMap.clear();
266 InstrMapping.clear();
267 UniqueInstrAllocator.Reset();
268 TemporaryInsts.clear();
269 CSEOpt.reset();
270 MRI = nullptr;
271 MF = nullptr;
272#ifndef NDEBUG
273 OpcodeHitTable.clear();
274#endif
275}
276
277#ifndef NDEBUG
278static const char *stringify(const MachineInstr *MI, std::string &S) {
279 raw_string_ostream OS(S);
280 OS << *MI;
281 return OS.str().c_str();
282}
283#endif
284
285Error GISelCSEInfo::verify() {
286#ifndef NDEBUG
287 std::string S1, S2;
288 handleRecordedInsts();
289 // For each instruction in map from MI -> UMI,
290 // Profile(MI) and make sure UMI is found for that profile.
291 for (auto &It : InstrMapping) {
292 FoldingSetNodeID TmpID;
293 GISelInstProfileBuilder(TmpID, *MRI).addNodeID(It.first);
294 void *InsertPos;
295 UniqueMachineInstr *FoundNode =
296 CSEMap.FindNodeOrInsertPos(TmpID, InsertPos);
297 if (FoundNode != It.second)
298 return createStringError(std::errc::not_supported,
299 "CSEMap mismatch, InstrMapping has MIs without "
300 "corresponding Nodes in CSEMap:\n%s",
301 stringify(It.second->MI, S1));
302 }
303
304 // For every node in the CSEMap, make sure that the InstrMapping
305 // points to it.
306 for (const UniqueMachineInstr &UMI : CSEMap) {
307 if (!InstrMapping.count(UMI.MI))
308 return createStringError(std::errc::not_supported,
309 "Node in CSE without InstrMapping:\n%s",
310 stringify(UMI.MI, S1));
311
312 if (InstrMapping[UMI.MI] != &UMI)
313 return createStringError(std::make_error_code(std::errc::not_supported),
314 "Mismatch in CSE mapping:\n%s\n%s",
315 stringify(InstrMapping[UMI.MI]->MI, S1),
316 stringify(UMI.MI, S2));
317 }
318#endif
319 return Error::success();
320}
321
322void GISelCSEInfo::print() {
323 LLVM_DEBUG({
324 for (auto &It : OpcodeHitTable)
325 dbgs() << "CSEInfo::CSE Hit for Opc " << It.first << " : " << It.second
326 << "\n";
327 });
328}
329/// -----------------------------------------
330// ---- Profiling methods for FoldingSetNode --- //
331const GISelInstProfileBuilder &
332GISelInstProfileBuilder::addNodeID(const MachineInstr *MI) const {
333 addNodeIDMBB(MBB: MI->getParent());
334 addNodeIDOpcode(Opc: MI->getOpcode());
335 for (const auto &Op : MI->operands())
336 addNodeIDMachineOperand(MO: Op);
337 addNodeIDFlag(Flag: MI->getFlags());
338 return *this;
339}
340
341const GISelInstProfileBuilder &
342GISelInstProfileBuilder::addNodeIDOpcode(unsigned Opc) const {
343 ID.AddInteger(I: Opc);
344 return *this;
345}
346
347const GISelInstProfileBuilder &
348GISelInstProfileBuilder::addNodeIDRegType(const LLT Ty) const {
349 uint64_t Val = Ty.getUniqueRAWLLTData();
350 ID.AddInteger(I: Val);
351 return *this;
352}
353
354const GISelInstProfileBuilder &
355GISelInstProfileBuilder::addNodeIDRegType(const TargetRegisterClass *RC) const {
356 ID.AddPointer(Ptr: RC);
357 return *this;
358}
359
360const GISelInstProfileBuilder &
361GISelInstProfileBuilder::addNodeIDRegType(const RegisterBank *RB) const {
362 ID.AddPointer(Ptr: RB);
363 return *this;
364}
365
366const GISelInstProfileBuilder &GISelInstProfileBuilder::addNodeIDRegType(
367 MachineRegisterInfo::VRegAttrs Attrs) const {
368 addNodeIDRegType(Ty: Attrs.Ty);
369
370 const RegClassOrRegBank &RCOrRB = Attrs.RCOrRB;
371 if (RCOrRB) {
372 if (const auto *RB = dyn_cast_if_present<const RegisterBank *>(Val: RCOrRB))
373 addNodeIDRegType(RB);
374 else
375 addNodeIDRegType(RC: cast<const TargetRegisterClass *>(Val: RCOrRB));
376 }
377 return *this;
378}
379
380const GISelInstProfileBuilder &
381GISelInstProfileBuilder::addNodeIDImmediate(int64_t Imm) const {
382 ID.AddInteger(I: Imm);
383 return *this;
384}
385
386const GISelInstProfileBuilder &
387GISelInstProfileBuilder::addNodeIDRegNum(Register Reg) const {
388 ID.AddInteger(I: Reg.id());
389 return *this;
390}
391
392const GISelInstProfileBuilder &
393GISelInstProfileBuilder::addNodeIDRegType(const Register Reg) const {
394 addNodeIDMachineOperand(MO: MachineOperand::CreateReg(Reg, isDef: false));
395 return *this;
396}
397
398const GISelInstProfileBuilder &
399GISelInstProfileBuilder::addNodeIDMBB(const MachineBasicBlock *MBB) const {
400 ID.AddPointer(Ptr: MBB);
401 return *this;
402}
403
404const GISelInstProfileBuilder &
405GISelInstProfileBuilder::addNodeIDFlag(unsigned Flag) const {
406 if (Flag)
407 ID.AddInteger(I: Flag);
408 return *this;
409}
410
411const GISelInstProfileBuilder &
412GISelInstProfileBuilder::addNodeIDReg(Register Reg) const {
413 addNodeIDRegType(Attrs: MRI.getVRegAttrs(Reg));
414 return *this;
415}
416
417const GISelInstProfileBuilder &GISelInstProfileBuilder::addNodeIDMachineOperand(
418 const MachineOperand &MO) const {
419 if (MO.isReg()) {
420 Register Reg = MO.getReg();
421 if (!MO.isDef())
422 addNodeIDRegNum(Reg);
423
424 // Profile the register properties.
425 addNodeIDReg(Reg);
426 assert(!MO.isImplicit() && "Unhandled case");
427 } else if (MO.isImm())
428 ID.AddInteger(I: MO.getImm());
429 else if (MO.isCImm())
430 ID.AddPointer(Ptr: MO.getCImm());
431 else if (MO.isFPImm())
432 ID.AddPointer(Ptr: MO.getFPImm());
433 else if (MO.isPredicate())
434 ID.AddInteger(I: MO.getPredicate());
435 else
436 llvm_unreachable("Unhandled operand type");
437 // Handle other types
438 return *this;
439}
440
441GISelCSEInfo &
442GISelCSEAnalysisWrapper::get(std::unique_ptr<CSEConfigBase> CSEOpt,
443 bool Recompute) {
444 if (!AlreadyComputed || Recompute) {
445 Info.releaseMemory();
446 Info.setCSEConfig(std::move(CSEOpt));
447 Info.analyze(MF&: *MF);
448 AlreadyComputed = true;
449 }
450 return Info;
451}
452void GISelCSEAnalysisWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
453 AU.setPreservesAll();
454 MachineFunctionPass::getAnalysisUsage(AU);
455}
456
457bool GISelCSEAnalysisWrapperPass::runOnMachineFunction(MachineFunction &MF) {
458 releaseMemory();
459 Wrapper.setMF(MF);
460 return false;
461}
462