1 //===- LoopUnrollAndJam.cpp - Loop unroll and jam pass --------------------===//
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 pass implements an unroll and jam pass. Most of the work is done by
10 // Utils/UnrollLoopAndJam.cpp.
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/Transforms/Scalar/LoopUnrollAndJamPass.h"
14 #include "llvm/ADT/ArrayRef.h"
15 #include "llvm/ADT/None.h"
16 #include "llvm/ADT/Optional.h"
17 #include "llvm/ADT/PriorityWorklist.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/Analysis/AssumptionCache.h"
21 #include "llvm/Analysis/CodeMetrics.h"
22 #include "llvm/Analysis/DependenceAnalysis.h"
23 #include "llvm/Analysis/LoopAnalysisManager.h"
24 #include "llvm/Analysis/LoopInfo.h"
25 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
26 #include "llvm/Analysis/ScalarEvolution.h"
27 #include "llvm/Analysis/TargetTransformInfo.h"
28 #include "llvm/IR/BasicBlock.h"
29 #include "llvm/IR/Constants.h"
30 #include "llvm/IR/Dominators.h"
31 #include "llvm/IR/Function.h"
32 #include "llvm/IR/Instructions.h"
33 #include "llvm/IR/Metadata.h"
34 #include "llvm/IR/PassManager.h"
35 #include "llvm/InitializePasses.h"
36 #include "llvm/Pass.h"
37 #include "llvm/PassRegistry.h"
38 #include "llvm/Support/Casting.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include "llvm/Transforms/Scalar.h"
44 #include "llvm/Transforms/Utils/LoopPeel.h"
45 #include "llvm/Transforms/Utils/LoopSimplify.h"
46 #include "llvm/Transforms/Utils/LoopUtils.h"
47 #include "llvm/Transforms/Utils/UnrollLoop.h"
48 #include <cassert>
49 #include <cstdint>
50 #include <vector>
51
52 namespace llvm {
53 class Instruction;
54 class Value;
55 } // namespace llvm
56
57 using namespace llvm;
58
59 #define DEBUG_TYPE "loop-unroll-and-jam"
60
61 /// @{
62 /// Metadata attribute names
63 static const char *const LLVMLoopUnrollAndJamFollowupAll =
64 "llvm.loop.unroll_and_jam.followup_all";
65 static const char *const LLVMLoopUnrollAndJamFollowupInner =
66 "llvm.loop.unroll_and_jam.followup_inner";
67 static const char *const LLVMLoopUnrollAndJamFollowupOuter =
68 "llvm.loop.unroll_and_jam.followup_outer";
69 static const char *const LLVMLoopUnrollAndJamFollowupRemainderInner =
70 "llvm.loop.unroll_and_jam.followup_remainder_inner";
71 static const char *const LLVMLoopUnrollAndJamFollowupRemainderOuter =
72 "llvm.loop.unroll_and_jam.followup_remainder_outer";
73 /// @}
74
75 static cl::opt<bool>
76 AllowUnrollAndJam("allow-unroll-and-jam", cl::Hidden,
77 cl::desc("Allows loops to be unroll-and-jammed."));
78
79 static cl::opt<unsigned> UnrollAndJamCount(
80 "unroll-and-jam-count", cl::Hidden,
81 cl::desc("Use this unroll count for all loops including those with "
82 "unroll_and_jam_count pragma values, for testing purposes"));
83
84 static cl::opt<unsigned> UnrollAndJamThreshold(
85 "unroll-and-jam-threshold", cl::init(60), cl::Hidden,
86 cl::desc("Threshold to use for inner loop when doing unroll and jam."));
87
88 static cl::opt<unsigned> PragmaUnrollAndJamThreshold(
89 "pragma-unroll-and-jam-threshold", cl::init(1024), cl::Hidden,
90 cl::desc("Unrolled size limit for loops with an unroll_and_jam(full) or "
91 "unroll_count pragma."));
92
93 // Returns the loop hint metadata node with the given name (for example,
94 // "llvm.loop.unroll.count"). If no such metadata node exists, then nullptr is
95 // returned.
getUnrollMetadataForLoop(const Loop * L,StringRef Name)96 static MDNode *getUnrollMetadataForLoop(const Loop *L, StringRef Name) {
97 if (MDNode *LoopID = L->getLoopID())
98 return GetUnrollMetadata(LoopID, Name);
99 return nullptr;
100 }
101
102 // Returns true if the loop has any metadata starting with Prefix. For example a
103 // Prefix of "llvm.loop.unroll." returns true if we have any unroll metadata.
hasAnyUnrollPragma(const Loop * L,StringRef Prefix)104 static bool hasAnyUnrollPragma(const Loop *L, StringRef Prefix) {
105 if (MDNode *LoopID = L->getLoopID()) {
106 // First operand should refer to the loop id itself.
107 assert(LoopID->getNumOperands() > 0 && "requires at least one operand");
108 assert(LoopID->getOperand(0) == LoopID && "invalid loop id");
109
110 for (unsigned I = 1, E = LoopID->getNumOperands(); I < E; ++I) {
111 MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(I));
112 if (!MD)
113 continue;
114
115 MDString *S = dyn_cast<MDString>(MD->getOperand(0));
116 if (!S)
117 continue;
118
119 if (S->getString().startswith(Prefix))
120 return true;
121 }
122 }
123 return false;
124 }
125
126 // Returns true if the loop has an unroll_and_jam(enable) pragma.
hasUnrollAndJamEnablePragma(const Loop * L)127 static bool hasUnrollAndJamEnablePragma(const Loop *L) {
128 return getUnrollMetadataForLoop(L, "llvm.loop.unroll_and_jam.enable");
129 }
130
131 // If loop has an unroll_and_jam_count pragma return the (necessarily
132 // positive) value from the pragma. Otherwise return 0.
unrollAndJamCountPragmaValue(const Loop * L)133 static unsigned unrollAndJamCountPragmaValue(const Loop *L) {
134 MDNode *MD = getUnrollMetadataForLoop(L, "llvm.loop.unroll_and_jam.count");
135 if (MD) {
136 assert(MD->getNumOperands() == 2 &&
137 "Unroll count hint metadata should have two operands.");
138 unsigned Count =
139 mdconst::extract<ConstantInt>(MD->getOperand(1))->getZExtValue();
140 assert(Count >= 1 && "Unroll count must be positive.");
141 return Count;
142 }
143 return 0;
144 }
145
146 // Returns loop size estimation for unrolled loop.
147 static uint64_t
getUnrollAndJammedLoopSize(unsigned LoopSize,TargetTransformInfo::UnrollingPreferences & UP)148 getUnrollAndJammedLoopSize(unsigned LoopSize,
149 TargetTransformInfo::UnrollingPreferences &UP) {
150 assert(LoopSize >= UP.BEInsns && "LoopSize should not be less than BEInsns!");
151 return static_cast<uint64_t>(LoopSize - UP.BEInsns) * UP.Count + UP.BEInsns;
152 }
153
154 // Calculates unroll and jam count and writes it to UP.Count. Returns true if
155 // unroll count was set explicitly.
computeUnrollAndJamCount(Loop * L,Loop * SubLoop,const TargetTransformInfo & TTI,DominatorTree & DT,LoopInfo * LI,ScalarEvolution & SE,const SmallPtrSetImpl<const Value * > & EphValues,OptimizationRemarkEmitter * ORE,unsigned OuterTripCount,unsigned OuterTripMultiple,unsigned OuterLoopSize,unsigned InnerTripCount,unsigned InnerLoopSize,TargetTransformInfo::UnrollingPreferences & UP,TargetTransformInfo::PeelingPreferences & PP)156 static bool computeUnrollAndJamCount(
157 Loop *L, Loop *SubLoop, const TargetTransformInfo &TTI, DominatorTree &DT,
158 LoopInfo *LI, ScalarEvolution &SE,
159 const SmallPtrSetImpl<const Value *> &EphValues,
160 OptimizationRemarkEmitter *ORE, unsigned OuterTripCount,
161 unsigned OuterTripMultiple, unsigned OuterLoopSize, unsigned InnerTripCount,
162 unsigned InnerLoopSize, TargetTransformInfo::UnrollingPreferences &UP,
163 TargetTransformInfo::PeelingPreferences &PP) {
164 // First up use computeUnrollCount from the loop unroller to get a count
165 // for unrolling the outer loop, plus any loops requiring explicit
166 // unrolling we leave to the unroller. This uses UP.Threshold /
167 // UP.PartialThreshold / UP.MaxCount to come up with sensible loop values.
168 // We have already checked that the loop has no unroll.* pragmas.
169 unsigned MaxTripCount = 0;
170 bool UseUpperBound = false;
171 bool ExplicitUnroll = computeUnrollCount(
172 L, TTI, DT, LI, SE, EphValues, ORE, OuterTripCount, MaxTripCount,
173 /*MaxOrZero*/ false, OuterTripMultiple, OuterLoopSize, UP, PP,
174 UseUpperBound);
175 if (ExplicitUnroll || UseUpperBound) {
176 // If the user explicitly set the loop as unrolled, dont UnJ it. Leave it
177 // for the unroller instead.
178 LLVM_DEBUG(dbgs() << "Won't unroll-and-jam; explicit count set by "
179 "computeUnrollCount\n");
180 UP.Count = 0;
181 return false;
182 }
183
184 // Override with any explicit Count from the "unroll-and-jam-count" option.
185 bool UserUnrollCount = UnrollAndJamCount.getNumOccurrences() > 0;
186 if (UserUnrollCount) {
187 UP.Count = UnrollAndJamCount;
188 UP.Force = true;
189 if (UP.AllowRemainder &&
190 getUnrollAndJammedLoopSize(OuterLoopSize, UP) < UP.Threshold &&
191 getUnrollAndJammedLoopSize(InnerLoopSize, UP) <
192 UP.UnrollAndJamInnerLoopThreshold)
193 return true;
194 }
195
196 // Check for unroll_and_jam pragmas
197 unsigned PragmaCount = unrollAndJamCountPragmaValue(L);
198 if (PragmaCount > 0) {
199 UP.Count = PragmaCount;
200 UP.Runtime = true;
201 UP.Force = true;
202 if ((UP.AllowRemainder || (OuterTripMultiple % PragmaCount == 0)) &&
203 getUnrollAndJammedLoopSize(OuterLoopSize, UP) < UP.Threshold &&
204 getUnrollAndJammedLoopSize(InnerLoopSize, UP) <
205 UP.UnrollAndJamInnerLoopThreshold)
206 return true;
207 }
208
209 bool PragmaEnableUnroll = hasUnrollAndJamEnablePragma(L);
210 bool ExplicitUnrollAndJamCount = PragmaCount > 0 || UserUnrollCount;
211 bool ExplicitUnrollAndJam = PragmaEnableUnroll || ExplicitUnrollAndJamCount;
212
213 // If the loop has an unrolling pragma, we want to be more aggressive with
214 // unrolling limits.
215 if (ExplicitUnrollAndJam)
216 UP.UnrollAndJamInnerLoopThreshold = PragmaUnrollAndJamThreshold;
217
218 if (!UP.AllowRemainder && getUnrollAndJammedLoopSize(InnerLoopSize, UP) >=
219 UP.UnrollAndJamInnerLoopThreshold) {
220 LLVM_DEBUG(dbgs() << "Won't unroll-and-jam; can't create remainder and "
221 "inner loop too large\n");
222 UP.Count = 0;
223 return false;
224 }
225
226 // We have a sensible limit for the outer loop, now adjust it for the inner
227 // loop and UP.UnrollAndJamInnerLoopThreshold. If the outer limit was set
228 // explicitly, we want to stick to it.
229 if (!ExplicitUnrollAndJamCount && UP.AllowRemainder) {
230 while (UP.Count != 0 && getUnrollAndJammedLoopSize(InnerLoopSize, UP) >=
231 UP.UnrollAndJamInnerLoopThreshold)
232 UP.Count--;
233 }
234
235 // If we are explicitly unroll and jamming, we are done. Otherwise there are a
236 // number of extra performance heuristics to check.
237 if (ExplicitUnrollAndJam)
238 return true;
239
240 // If the inner loop count is known and small, leave the entire loop nest to
241 // be the unroller
242 if (InnerTripCount && InnerLoopSize * InnerTripCount < UP.Threshold) {
243 LLVM_DEBUG(dbgs() << "Won't unroll-and-jam; small inner loop count is "
244 "being left for the unroller\n");
245 UP.Count = 0;
246 return false;
247 }
248
249 // Check for situations where UnJ is likely to be unprofitable. Including
250 // subloops with more than 1 block.
251 if (SubLoop->getBlocks().size() != 1) {
252 LLVM_DEBUG(
253 dbgs() << "Won't unroll-and-jam; More than one inner loop block\n");
254 UP.Count = 0;
255 return false;
256 }
257
258 // Limit to loops where there is something to gain from unrolling and
259 // jamming the loop. In this case, look for loads that are invariant in the
260 // outer loop and can become shared.
261 unsigned NumInvariant = 0;
262 for (BasicBlock *BB : SubLoop->getBlocks()) {
263 for (Instruction &I : *BB) {
264 if (auto *Ld = dyn_cast<LoadInst>(&I)) {
265 Value *V = Ld->getPointerOperand();
266 const SCEV *LSCEV = SE.getSCEVAtScope(V, L);
267 if (SE.isLoopInvariant(LSCEV, L))
268 NumInvariant++;
269 }
270 }
271 }
272 if (NumInvariant == 0) {
273 LLVM_DEBUG(dbgs() << "Won't unroll-and-jam; No loop invariant loads\n");
274 UP.Count = 0;
275 return false;
276 }
277
278 return false;
279 }
280
281 static LoopUnrollResult
tryToUnrollAndJamLoop(Loop * L,DominatorTree & DT,LoopInfo * LI,ScalarEvolution & SE,const TargetTransformInfo & TTI,AssumptionCache & AC,DependenceInfo & DI,OptimizationRemarkEmitter & ORE,int OptLevel)282 tryToUnrollAndJamLoop(Loop *L, DominatorTree &DT, LoopInfo *LI,
283 ScalarEvolution &SE, const TargetTransformInfo &TTI,
284 AssumptionCache &AC, DependenceInfo &DI,
285 OptimizationRemarkEmitter &ORE, int OptLevel) {
286 TargetTransformInfo::UnrollingPreferences UP =
287 gatherUnrollingPreferences(L, SE, TTI, nullptr, nullptr, OptLevel, None,
288 None, None, None, None, None);
289 TargetTransformInfo::PeelingPreferences PP =
290 gatherPeelingPreferences(L, SE, TTI, None, None);
291
292 TransformationMode EnableMode = hasUnrollAndJamTransformation(L);
293 if (EnableMode & TM_Disable)
294 return LoopUnrollResult::Unmodified;
295 if (EnableMode & TM_ForcedByUser)
296 UP.UnrollAndJam = true;
297
298 if (AllowUnrollAndJam.getNumOccurrences() > 0)
299 UP.UnrollAndJam = AllowUnrollAndJam;
300 if (UnrollAndJamThreshold.getNumOccurrences() > 0)
301 UP.UnrollAndJamInnerLoopThreshold = UnrollAndJamThreshold;
302 // Exit early if unrolling is disabled.
303 if (!UP.UnrollAndJam || UP.UnrollAndJamInnerLoopThreshold == 0)
304 return LoopUnrollResult::Unmodified;
305
306 LLVM_DEBUG(dbgs() << "Loop Unroll and Jam: F["
307 << L->getHeader()->getParent()->getName() << "] Loop %"
308 << L->getHeader()->getName() << "\n");
309
310 // A loop with any unroll pragma (enabling/disabling/count/etc) is left for
311 // the unroller, so long as it does not explicitly have unroll_and_jam
312 // metadata. This means #pragma nounroll will disable unroll and jam as well
313 // as unrolling
314 if (hasAnyUnrollPragma(L, "llvm.loop.unroll.") &&
315 !hasAnyUnrollPragma(L, "llvm.loop.unroll_and_jam.")) {
316 LLVM_DEBUG(dbgs() << " Disabled due to pragma.\n");
317 return LoopUnrollResult::Unmodified;
318 }
319
320 if (!isSafeToUnrollAndJam(L, SE, DT, DI, *LI)) {
321 LLVM_DEBUG(dbgs() << " Disabled due to not being safe.\n");
322 return LoopUnrollResult::Unmodified;
323 }
324
325 // Approximate the loop size and collect useful info
326 unsigned NumInlineCandidates;
327 bool NotDuplicatable;
328 bool Convergent;
329 SmallPtrSet<const Value *, 32> EphValues;
330 CodeMetrics::collectEphemeralValues(L, &AC, EphValues);
331 Loop *SubLoop = L->getSubLoops()[0];
332 unsigned InnerLoopSize =
333 ApproximateLoopSize(SubLoop, NumInlineCandidates, NotDuplicatable,
334 Convergent, TTI, EphValues, UP.BEInsns);
335 unsigned OuterLoopSize =
336 ApproximateLoopSize(L, NumInlineCandidates, NotDuplicatable, Convergent,
337 TTI, EphValues, UP.BEInsns);
338 LLVM_DEBUG(dbgs() << " Outer Loop Size: " << OuterLoopSize << "\n");
339 LLVM_DEBUG(dbgs() << " Inner Loop Size: " << InnerLoopSize << "\n");
340 if (NotDuplicatable) {
341 LLVM_DEBUG(dbgs() << " Not unrolling loop which contains non-duplicatable "
342 "instructions.\n");
343 return LoopUnrollResult::Unmodified;
344 }
345 if (NumInlineCandidates != 0) {
346 LLVM_DEBUG(dbgs() << " Not unrolling loop with inlinable calls.\n");
347 return LoopUnrollResult::Unmodified;
348 }
349 if (Convergent) {
350 LLVM_DEBUG(
351 dbgs() << " Not unrolling loop with convergent instructions.\n");
352 return LoopUnrollResult::Unmodified;
353 }
354
355 // Save original loop IDs for after the transformation.
356 MDNode *OrigOuterLoopID = L->getLoopID();
357 MDNode *OrigSubLoopID = SubLoop->getLoopID();
358
359 // To assign the loop id of the epilogue, assign it before unrolling it so it
360 // is applied to every inner loop of the epilogue. We later apply the loop ID
361 // for the jammed inner loop.
362 Optional<MDNode *> NewInnerEpilogueLoopID = makeFollowupLoopID(
363 OrigOuterLoopID, {LLVMLoopUnrollAndJamFollowupAll,
364 LLVMLoopUnrollAndJamFollowupRemainderInner});
365 if (NewInnerEpilogueLoopID.hasValue())
366 SubLoop->setLoopID(NewInnerEpilogueLoopID.getValue());
367
368 // Find trip count and trip multiple
369 BasicBlock *Latch = L->getLoopLatch();
370 BasicBlock *SubLoopLatch = SubLoop->getLoopLatch();
371 unsigned OuterTripCount = SE.getSmallConstantTripCount(L, Latch);
372 unsigned OuterTripMultiple = SE.getSmallConstantTripMultiple(L, Latch);
373 unsigned InnerTripCount = SE.getSmallConstantTripCount(SubLoop, SubLoopLatch);
374
375 // Decide if, and by how much, to unroll
376 bool IsCountSetExplicitly = computeUnrollAndJamCount(
377 L, SubLoop, TTI, DT, LI, SE, EphValues, &ORE, OuterTripCount,
378 OuterTripMultiple, OuterLoopSize, InnerTripCount, InnerLoopSize, UP, PP);
379 if (UP.Count <= 1)
380 return LoopUnrollResult::Unmodified;
381 // Unroll factor (Count) must be less or equal to TripCount.
382 if (OuterTripCount && UP.Count > OuterTripCount)
383 UP.Count = OuterTripCount;
384
385 Loop *EpilogueOuterLoop = nullptr;
386 LoopUnrollResult UnrollResult = UnrollAndJamLoop(
387 L, UP.Count, OuterTripCount, OuterTripMultiple, UP.UnrollRemainder, LI,
388 &SE, &DT, &AC, &TTI, &ORE, &EpilogueOuterLoop);
389
390 // Assign new loop attributes.
391 if (EpilogueOuterLoop) {
392 Optional<MDNode *> NewOuterEpilogueLoopID = makeFollowupLoopID(
393 OrigOuterLoopID, {LLVMLoopUnrollAndJamFollowupAll,
394 LLVMLoopUnrollAndJamFollowupRemainderOuter});
395 if (NewOuterEpilogueLoopID.hasValue())
396 EpilogueOuterLoop->setLoopID(NewOuterEpilogueLoopID.getValue());
397 }
398
399 Optional<MDNode *> NewInnerLoopID =
400 makeFollowupLoopID(OrigOuterLoopID, {LLVMLoopUnrollAndJamFollowupAll,
401 LLVMLoopUnrollAndJamFollowupInner});
402 if (NewInnerLoopID.hasValue())
403 SubLoop->setLoopID(NewInnerLoopID.getValue());
404 else
405 SubLoop->setLoopID(OrigSubLoopID);
406
407 if (UnrollResult == LoopUnrollResult::PartiallyUnrolled) {
408 Optional<MDNode *> NewOuterLoopID = makeFollowupLoopID(
409 OrigOuterLoopID,
410 {LLVMLoopUnrollAndJamFollowupAll, LLVMLoopUnrollAndJamFollowupOuter});
411 if (NewOuterLoopID.hasValue()) {
412 L->setLoopID(NewOuterLoopID.getValue());
413
414 // Do not setLoopAlreadyUnrolled if a followup was given.
415 return UnrollResult;
416 }
417 }
418
419 // If loop has an unroll count pragma or unrolled by explicitly set count
420 // mark loop as unrolled to prevent unrolling beyond that requested.
421 if (UnrollResult != LoopUnrollResult::FullyUnrolled && IsCountSetExplicitly)
422 L->setLoopAlreadyUnrolled();
423
424 return UnrollResult;
425 }
426
tryToUnrollAndJamLoop(Function & F,DominatorTree & DT,LoopInfo & LI,ScalarEvolution & SE,const TargetTransformInfo & TTI,AssumptionCache & AC,DependenceInfo & DI,OptimizationRemarkEmitter & ORE,int OptLevel)427 static bool tryToUnrollAndJamLoop(Function &F, DominatorTree &DT, LoopInfo &LI,
428 ScalarEvolution &SE,
429 const TargetTransformInfo &TTI,
430 AssumptionCache &AC, DependenceInfo &DI,
431 OptimizationRemarkEmitter &ORE,
432 int OptLevel) {
433 bool DidSomething = false;
434
435 // The loop unroll and jam pass requires loops to be in simplified form, and
436 // also needs LCSSA. Since simplification may add new inner loops, it has to
437 // run before the legality and profitability checks. This means running the
438 // loop unroll and jam pass will simplify all loops, regardless of whether
439 // anything end up being unroll and jammed.
440 for (auto &L : LI) {
441 DidSomething |=
442 simplifyLoop(L, &DT, &LI, &SE, &AC, nullptr, false /* PreserveLCSSA */);
443 DidSomething |= formLCSSARecursively(*L, DT, &LI, &SE);
444 }
445
446 // Add the loop nests in the reverse order of LoopInfo. See method
447 // declaration.
448 SmallPriorityWorklist<Loop *, 4> Worklist;
449 appendLoopsToWorklist(LI, Worklist);
450 while (!Worklist.empty()) {
451 Loop *L = Worklist.pop_back_val();
452 LoopUnrollResult Result =
453 tryToUnrollAndJamLoop(L, DT, &LI, SE, TTI, AC, DI, ORE, OptLevel);
454 if (Result != LoopUnrollResult::Unmodified)
455 DidSomething = true;
456 }
457
458 return DidSomething;
459 }
460
461 namespace {
462
463 class LoopUnrollAndJam : public FunctionPass {
464 public:
465 static char ID; // Pass ID, replacement for typeid
466 unsigned OptLevel;
467
LoopUnrollAndJam(int OptLevel=2)468 LoopUnrollAndJam(int OptLevel = 2) : FunctionPass(ID), OptLevel(OptLevel) {
469 initializeLoopUnrollAndJamPass(*PassRegistry::getPassRegistry());
470 }
471
runOnFunction(Function & F)472 bool runOnFunction(Function &F) override {
473 if (skipFunction(F))
474 return false;
475
476 auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
477 LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
478 ScalarEvolution &SE = getAnalysis<ScalarEvolutionWrapperPass>().getSE();
479 const TargetTransformInfo &TTI =
480 getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
481 auto &AC = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
482 auto &DI = getAnalysis<DependenceAnalysisWrapperPass>().getDI();
483 auto &ORE = getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
484
485 return tryToUnrollAndJamLoop(F, DT, LI, SE, TTI, AC, DI, ORE, OptLevel);
486 }
487
488 /// This transformation requires natural loop information & requires that
489 /// loop preheaders be inserted into the CFG...
getAnalysisUsage(AnalysisUsage & AU) const490 void getAnalysisUsage(AnalysisUsage &AU) const override {
491 AU.addRequired<DominatorTreeWrapperPass>();
492 AU.addRequired<LoopInfoWrapperPass>();
493 AU.addRequired<ScalarEvolutionWrapperPass>();
494 AU.addRequired<TargetTransformInfoWrapperPass>();
495 AU.addRequired<AssumptionCacheTracker>();
496 AU.addRequired<DependenceAnalysisWrapperPass>();
497 AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
498 }
499 };
500
501 } // end anonymous namespace
502
503 char LoopUnrollAndJam::ID = 0;
504
505 INITIALIZE_PASS_BEGIN(LoopUnrollAndJam, "loop-unroll-and-jam",
506 "Unroll and Jam loops", false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)507 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
508 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
509 INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
510 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
511 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
512 INITIALIZE_PASS_DEPENDENCY(DependenceAnalysisWrapperPass)
513 INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)
514 INITIALIZE_PASS_END(LoopUnrollAndJam, "loop-unroll-and-jam",
515 "Unroll and Jam loops", false, false)
516
517 Pass *llvm::createLoopUnrollAndJamPass(int OptLevel) {
518 return new LoopUnrollAndJam(OptLevel);
519 }
520
run(Function & F,FunctionAnalysisManager & AM)521 PreservedAnalyses LoopUnrollAndJamPass::run(Function &F,
522 FunctionAnalysisManager &AM) {
523 ScalarEvolution &SE = AM.getResult<ScalarEvolutionAnalysis>(F);
524 LoopInfo &LI = AM.getResult<LoopAnalysis>(F);
525 TargetTransformInfo &TTI = AM.getResult<TargetIRAnalysis>(F);
526 AssumptionCache &AC = AM.getResult<AssumptionAnalysis>(F);
527 DominatorTree &DT = AM.getResult<DominatorTreeAnalysis>(F);
528 DependenceInfo &DI = AM.getResult<DependenceAnalysis>(F);
529 OptimizationRemarkEmitter &ORE =
530 AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
531
532 if (!tryToUnrollAndJamLoop(F, DT, LI, SE, TTI, AC, DI, ORE, OptLevel))
533 return PreservedAnalyses::all();
534
535 return getLoopPassPreservedAnalyses();
536 }
537