1 //===-- PredicateInfo.cpp - PredicateInfo Builder--------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------===//
10 // This file implements the PredicateInfo class.
12 //===----------------------------------------------------------------===//
14 #include "llvm/Transforms/Utils/PredicateInfo.h"
15 #include "llvm/ADT/DenseMap.h"
16 #include "llvm/ADT/DepthFirstIterator.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/AssumptionCache.h"
21 #include "llvm/Analysis/CFG.h"
22 #include "llvm/IR/AssemblyAnnotationWriter.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/Dominators.h"
25 #include "llvm/IR/GlobalVariable.h"
26 #include "llvm/IR/IRBuilder.h"
27 #include "llvm/IR/IntrinsicInst.h"
28 #include "llvm/IR/LLVMContext.h"
29 #include "llvm/IR/Metadata.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/PatternMatch.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/DebugCounter.h"
34 #include "llvm/Support/FormattedStream.h"
35 #include "llvm/Transforms/Scalar.h"
36 #include "llvm/Transforms/Utils/OrderedInstructions.h"
38 #define DEBUG_TYPE "predicateinfo"
40 using namespace PatternMatch;
41 using namespace llvm::PredicateInfoClasses;
43 INITIALIZE_PASS_BEGIN(PredicateInfoPrinterLegacyPass, "print-predicateinfo",
44 "PredicateInfo Printer", false, false)
45 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
46 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
47 INITIALIZE_PASS_END(PredicateInfoPrinterLegacyPass, "print-predicateinfo",
48 "PredicateInfo Printer", false, false)
49 static cl::opt<bool> VerifyPredicateInfo(
50 "verify-predicateinfo", cl::init(false), cl::Hidden,
51 cl::desc("Verify PredicateInfo in legacy printer pass."));
53 DEBUG_COUNTER(RenameCounter, "predicateinfo-rename",
54 "Controls which variables are renamed with predicateinfo")
55 // Given a predicate info that is a type of branching terminator, get the
57 const BasicBlock *getBranchBlock(const PredicateBase *PB) {
58 assert(isa<PredicateWithEdge>(PB) &&
59 "Only branches and switches should have PHIOnly defs that "
60 "require branch blocks.");
61 return cast<PredicateWithEdge>(PB)->From;
64 // Given a predicate info that is a type of branching terminator, get the
65 // branching terminator.
66 static Instruction *getBranchTerminator(const PredicateBase *PB) {
67 assert(isa<PredicateWithEdge>(PB) &&
68 "Not a predicate info type we know how to get a terminator from.");
69 return cast<PredicateWithEdge>(PB)->From->getTerminator();
72 // Given a predicate info that is a type of branching terminator, get the
73 // edge this predicate info represents
74 const std::pair<BasicBlock *, BasicBlock *>
75 getBlockEdge(const PredicateBase *PB) {
76 assert(isa<PredicateWithEdge>(PB) &&
77 "Not a predicate info type we know how to get an edge from.");
78 const auto *PEdge = cast<PredicateWithEdge>(PB);
79 return std::make_pair(PEdge->From, PEdge->To);
84 namespace PredicateInfoClasses {
86 // Operations that must appear first in the block.
88 // Operations that are somewhere in the middle of the block, and are sorted on
91 // Operations that must appear last in a block, like successor phi node uses.
95 // Associate global and local DFS info with defs and uses, so we can sort them
96 // into a global domination ordering.
100 unsigned int LocalNum = LN_Middle;
101 // Only one of Def or Use will be set.
102 Value *Def = nullptr;
104 // Neither PInfo nor EdgeOnly participate in the ordering
105 PredicateBase *PInfo = nullptr;
106 bool EdgeOnly = false;
109 // Perform a strict weak ordering on instructions and arguments.
110 static bool valueComesBefore(OrderedInstructions &OI, const Value *A,
112 auto *ArgA = dyn_cast_or_null<Argument>(A);
113 auto *ArgB = dyn_cast_or_null<Argument>(B);
119 return ArgA->getArgNo() < ArgB->getArgNo();
120 return OI.dominates(cast<Instruction>(A), cast<Instruction>(B));
123 // This compares ValueDFS structures, creating OrderedBasicBlocks where
124 // necessary to compare uses/defs in the same block. Doing so allows us to walk
125 // the minimum number of instructions necessary to compute our def/use ordering.
126 struct ValueDFS_Compare {
127 OrderedInstructions &OI;
128 ValueDFS_Compare(OrderedInstructions &OI) : OI(OI) {}
130 bool operator()(const ValueDFS &A, const ValueDFS &B) const {
133 // The only case we can't directly compare them is when they in the same
134 // block, and both have localnum == middle. In that case, we have to use
135 // comesbefore to see what the real ordering is, because they are in the
138 bool SameBlock = std::tie(A.DFSIn, A.DFSOut) == std::tie(B.DFSIn, B.DFSOut);
140 // We want to put the def that will get used for a given set of phi uses,
141 // before those phi uses.
142 // So we sort by edge, then by def.
143 // Note that only phi nodes uses and defs can come last.
144 if (SameBlock && A.LocalNum == LN_Last && B.LocalNum == LN_Last)
145 return comparePHIRelated(A, B);
147 if (!SameBlock || A.LocalNum != LN_Middle || B.LocalNum != LN_Middle)
148 return std::tie(A.DFSIn, A.DFSOut, A.LocalNum, A.Def, A.U) <
149 std::tie(B.DFSIn, B.DFSOut, B.LocalNum, B.Def, B.U);
150 return localComesBefore(A, B);
153 // For a phi use, or a non-materialized def, return the edge it represents.
154 const std::pair<BasicBlock *, BasicBlock *>
155 getBlockEdge(const ValueDFS &VD) const {
156 if (!VD.Def && VD.U) {
157 auto *PHI = cast<PHINode>(VD.U->getUser());
158 return std::make_pair(PHI->getIncomingBlock(*VD.U), PHI->getParent());
160 // This is really a non-materialized def.
161 return ::getBlockEdge(VD.PInfo);
164 // For two phi related values, return the ordering.
165 bool comparePHIRelated(const ValueDFS &A, const ValueDFS &B) const {
166 auto &ABlockEdge = getBlockEdge(A);
167 auto &BBlockEdge = getBlockEdge(B);
168 // Now sort by block edge and then defs before uses.
169 return std::tie(ABlockEdge, A.Def, A.U) < std::tie(BBlockEdge, B.Def, B.U);
172 // Get the definition of an instruction that occurs in the middle of a block.
173 Value *getMiddleDef(const ValueDFS &VD) const {
176 // It's possible for the defs and uses to be null. For branches, the local
177 // numbering will say the placed predicaeinfos should go first (IE
178 // LN_beginning), so we won't be in this function. For assumes, we will end
179 // up here, beause we need to order the def we will place relative to the
180 // assume. So for the purpose of ordering, we pretend the def is the assume
181 // because that is where we will insert the info.
184 "No def, no use, and no predicateinfo should not occur");
185 assert(isa<PredicateAssume>(VD.PInfo) &&
186 "Middle of block should only occur for assumes");
187 return cast<PredicateAssume>(VD.PInfo)->AssumeInst;
192 // Return either the Def, if it's not null, or the user of the Use, if the def
194 const Instruction *getDefOrUser(const Value *Def, const Use *U) const {
196 return cast<Instruction>(Def);
197 return cast<Instruction>(U->getUser());
200 // This performs the necessary local basic block ordering checks to tell
201 // whether A comes before B, where both are in the same basic block.
202 bool localComesBefore(const ValueDFS &A, const ValueDFS &B) const {
203 auto *ADef = getMiddleDef(A);
204 auto *BDef = getMiddleDef(B);
206 // See if we have real values or uses. If we have real values, we are
207 // guaranteed they are instructions or arguments. No matter what, we are
208 // guaranteed they are in the same block if they are instructions.
209 auto *ArgA = dyn_cast_or_null<Argument>(ADef);
210 auto *ArgB = dyn_cast_or_null<Argument>(BDef);
213 return valueComesBefore(OI, ArgA, ArgB);
215 auto *AInst = getDefOrUser(ADef, A.U);
216 auto *BInst = getDefOrUser(BDef, B.U);
217 return valueComesBefore(OI, AInst, BInst);
221 } // namespace PredicateInfoClasses
223 bool PredicateInfo::stackIsInScope(const ValueDFSStack &Stack,
224 const ValueDFS &VDUse) const {
227 // If it's a phi only use, make sure it's for this phi node edge, and that the
228 // use is in a phi node. If it's anything else, and the top of the stack is
229 // EdgeOnly, we need to pop the stack. We deliberately sort phi uses next to
230 // the defs they must go with so that we can know it's time to pop the stack
231 // when we hit the end of the phi uses for a given def.
232 if (Stack.back().EdgeOnly) {
235 auto *PHI = dyn_cast<PHINode>(VDUse.U->getUser());
239 BasicBlock *EdgePred = PHI->getIncomingBlock(*VDUse.U);
240 if (EdgePred != getBranchBlock(Stack.back().PInfo))
243 // Use dominates, which knows how to handle edge dominance.
244 return DT.dominates(getBlockEdge(Stack.back().PInfo), *VDUse.U);
247 return (VDUse.DFSIn >= Stack.back().DFSIn &&
248 VDUse.DFSOut <= Stack.back().DFSOut);
251 void PredicateInfo::popStackUntilDFSScope(ValueDFSStack &Stack,
252 const ValueDFS &VD) {
253 while (!Stack.empty() && !stackIsInScope(Stack, VD))
257 // Convert the uses of Op into a vector of uses, associating global and local
258 // DFS info with each one.
259 void PredicateInfo::convertUsesToDFSOrdered(
260 Value *Op, SmallVectorImpl<ValueDFS> &DFSOrderedSet) {
261 for (auto &U : Op->uses()) {
262 if (auto *I = dyn_cast<Instruction>(U.getUser())) {
264 // Put the phi node uses in the incoming block.
266 if (auto *PN = dyn_cast<PHINode>(I)) {
267 IBlock = PN->getIncomingBlock(U);
268 // Make phi node users appear last in the incoming block
270 VD.LocalNum = LN_Last;
272 // If it's not a phi node use, it is somewhere in the middle of the
274 IBlock = I->getParent();
275 VD.LocalNum = LN_Middle;
277 DomTreeNode *DomNode = DT.getNode(IBlock);
278 // It's possible our use is in an unreachable block. Skip it if so.
281 VD.DFSIn = DomNode->getDFSNumIn();
282 VD.DFSOut = DomNode->getDFSNumOut();
284 DFSOrderedSet.push_back(VD);
289 // Collect relevant operations from Comparison that we may want to insert copies
291 void collectCmpOps(CmpInst *Comparison, SmallVectorImpl<Value *> &CmpOperands) {
292 auto *Op0 = Comparison->getOperand(0);
293 auto *Op1 = Comparison->getOperand(1);
296 CmpOperands.push_back(Comparison);
297 // Only want real values, not constants. Additionally, operands with one use
298 // are only being used in the comparison, which means they will not be useful
299 // for us to consider for predicateinfo.
301 if ((isa<Instruction>(Op0) || isa<Argument>(Op0)) && !Op0->hasOneUse())
302 CmpOperands.push_back(Op0);
303 if ((isa<Instruction>(Op1) || isa<Argument>(Op1)) && !Op1->hasOneUse())
304 CmpOperands.push_back(Op1);
307 // Add Op, PB to the list of value infos for Op, and mark Op to be renamed.
308 void PredicateInfo::addInfoFor(SmallPtrSetImpl<Value *> &OpsToRename, Value *Op,
310 OpsToRename.insert(Op);
311 auto &OperandInfo = getOrCreateValueInfo(Op);
312 AllInfos.push_back(PB);
313 OperandInfo.Infos.push_back(PB);
316 // Process an assume instruction and place relevant operations we want to rename
318 void PredicateInfo::processAssume(IntrinsicInst *II, BasicBlock *AssumeBB,
319 SmallPtrSetImpl<Value *> &OpsToRename) {
320 // See if we have a comparison we support
321 SmallVector<Value *, 8> CmpOperands;
322 SmallVector<Value *, 2> ConditionsToProcess;
323 CmpInst::Predicate Pred;
324 Value *Operand = II->getOperand(0);
325 if (m_c_And(m_Cmp(Pred, m_Value(), m_Value()),
326 m_Cmp(Pred, m_Value(), m_Value()))
327 .match(II->getOperand(0))) {
328 ConditionsToProcess.push_back(cast<BinaryOperator>(Operand)->getOperand(0));
329 ConditionsToProcess.push_back(cast<BinaryOperator>(Operand)->getOperand(1));
330 ConditionsToProcess.push_back(Operand);
331 } else if (isa<CmpInst>(Operand)) {
333 ConditionsToProcess.push_back(Operand);
335 for (auto Cond : ConditionsToProcess) {
336 if (auto *Cmp = dyn_cast<CmpInst>(Cond)) {
337 collectCmpOps(Cmp, CmpOperands);
338 // Now add our copy infos for our operands
339 for (auto *Op : CmpOperands) {
340 auto *PA = new PredicateAssume(Op, II, Cmp);
341 addInfoFor(OpsToRename, Op, PA);
344 } else if (auto *BinOp = dyn_cast<BinaryOperator>(Cond)) {
345 // Otherwise, it should be an AND.
346 assert(BinOp->getOpcode() == Instruction::And &&
347 "Should have been an AND");
348 auto *PA = new PredicateAssume(BinOp, II, BinOp);
349 addInfoFor(OpsToRename, BinOp, PA);
351 llvm_unreachable("Unknown type of condition");
356 // Process a block terminating branch, and place relevant operations to be
357 // renamed into OpsToRename.
358 void PredicateInfo::processBranch(BranchInst *BI, BasicBlock *BranchBB,
359 SmallPtrSetImpl<Value *> &OpsToRename) {
360 BasicBlock *FirstBB = BI->getSuccessor(0);
361 BasicBlock *SecondBB = BI->getSuccessor(1);
362 SmallVector<BasicBlock *, 2> SuccsToProcess;
363 SuccsToProcess.push_back(FirstBB);
364 SuccsToProcess.push_back(SecondBB);
365 SmallVector<Value *, 2> ConditionsToProcess;
367 auto InsertHelper = [&](Value *Op, bool isAnd, bool isOr, Value *Cond) {
368 for (auto *Succ : SuccsToProcess) {
369 // Don't try to insert on a self-edge. This is mainly because we will
370 // eliminate during renaming anyway.
371 if (Succ == BranchBB)
373 bool TakenEdge = (Succ == FirstBB);
374 // For and, only insert on the true edge
375 // For or, only insert on the false edge
376 if ((isAnd && !TakenEdge) || (isOr && TakenEdge))
379 new PredicateBranch(Op, BranchBB, Succ, Cond, TakenEdge);
380 addInfoFor(OpsToRename, Op, PB);
381 if (!Succ->getSinglePredecessor())
382 EdgeUsesOnly.insert({BranchBB, Succ});
386 // Match combinations of conditions.
387 CmpInst::Predicate Pred;
390 SmallVector<Value *, 8> CmpOperands;
391 if (match(BI->getCondition(), m_And(m_Cmp(Pred, m_Value(), m_Value()),
392 m_Cmp(Pred, m_Value(), m_Value()))) ||
393 match(BI->getCondition(), m_Or(m_Cmp(Pred, m_Value(), m_Value()),
394 m_Cmp(Pred, m_Value(), m_Value())))) {
395 auto *BinOp = cast<BinaryOperator>(BI->getCondition());
396 if (BinOp->getOpcode() == Instruction::And)
398 else if (BinOp->getOpcode() == Instruction::Or)
400 ConditionsToProcess.push_back(BinOp->getOperand(0));
401 ConditionsToProcess.push_back(BinOp->getOperand(1));
402 ConditionsToProcess.push_back(BI->getCondition());
403 } else if (isa<CmpInst>(BI->getCondition())) {
404 ConditionsToProcess.push_back(BI->getCondition());
406 for (auto Cond : ConditionsToProcess) {
407 if (auto *Cmp = dyn_cast<CmpInst>(Cond)) {
408 collectCmpOps(Cmp, CmpOperands);
409 // Now add our copy infos for our operands
410 for (auto *Op : CmpOperands)
411 InsertHelper(Op, isAnd, isOr, Cmp);
412 } else if (auto *BinOp = dyn_cast<BinaryOperator>(Cond)) {
413 // This must be an AND or an OR.
414 assert((BinOp->getOpcode() == Instruction::And ||
415 BinOp->getOpcode() == Instruction::Or) &&
416 "Should have been an AND or an OR");
417 // The actual value of the binop is not subject to the same restrictions
418 // as the comparison. It's either true or false on the true/false branch.
419 InsertHelper(BinOp, false, false, BinOp);
421 llvm_unreachable("Unknown type of condition");
426 // Process a block terminating switch, and place relevant operations to be
427 // renamed into OpsToRename.
428 void PredicateInfo::processSwitch(SwitchInst *SI, BasicBlock *BranchBB,
429 SmallPtrSetImpl<Value *> &OpsToRename) {
430 Value *Op = SI->getCondition();
431 if ((!isa<Instruction>(Op) && !isa<Argument>(Op)) || Op->hasOneUse())
434 // Remember how many outgoing edges there are to every successor.
435 SmallDenseMap<BasicBlock *, unsigned, 16> SwitchEdges;
436 for (unsigned i = 0, e = SI->getNumSuccessors(); i != e; ++i) {
437 BasicBlock *TargetBlock = SI->getSuccessor(i);
438 ++SwitchEdges[TargetBlock];
441 // Now propagate info for each case value
442 for (auto C : SI->cases()) {
443 BasicBlock *TargetBlock = C.getCaseSuccessor();
444 if (SwitchEdges.lookup(TargetBlock) == 1) {
445 PredicateSwitch *PS = new PredicateSwitch(
446 Op, SI->getParent(), TargetBlock, C.getCaseValue(), SI);
447 addInfoFor(OpsToRename, Op, PS);
448 if (!TargetBlock->getSinglePredecessor())
449 EdgeUsesOnly.insert({BranchBB, TargetBlock});
454 // Build predicate info for our function
455 void PredicateInfo::buildPredicateInfo() {
456 DT.updateDFSNumbers();
457 // Collect operands to rename from all conditional branch terminators, as well
458 // as assume statements.
459 SmallPtrSet<Value *, 8> OpsToRename;
460 for (auto DTN : depth_first(DT.getRootNode())) {
461 BasicBlock *BranchBB = DTN->getBlock();
462 if (auto *BI = dyn_cast<BranchInst>(BranchBB->getTerminator())) {
463 if (!BI->isConditional())
465 // Can't insert conditional information if they all go to the same place.
466 if (BI->getSuccessor(0) == BI->getSuccessor(1))
468 processBranch(BI, BranchBB, OpsToRename);
469 } else if (auto *SI = dyn_cast<SwitchInst>(BranchBB->getTerminator())) {
470 processSwitch(SI, BranchBB, OpsToRename);
473 for (auto &Assume : AC.assumptions()) {
474 if (auto *II = dyn_cast_or_null<IntrinsicInst>(Assume))
475 processAssume(II, II->getParent(), OpsToRename);
477 // Now rename all our operations.
478 renameUses(OpsToRename);
481 // Given the renaming stack, make all the operands currently on the stack real
482 // by inserting them into the IR. Return the last operation's value.
483 Value *PredicateInfo::materializeStack(unsigned int &Counter,
484 ValueDFSStack &RenameStack,
486 // Find the first thing we have to materialize
487 auto RevIter = RenameStack.rbegin();
488 for (; RevIter != RenameStack.rend(); ++RevIter)
492 size_t Start = RevIter - RenameStack.rbegin();
493 // The maximum number of things we should be trying to materialize at once
494 // right now is 4, depending on if we had an assume, a branch, and both used
495 // and of conditions.
496 for (auto RenameIter = RenameStack.end() - Start;
497 RenameIter != RenameStack.end(); ++RenameIter) {
499 RenameIter == RenameStack.begin() ? OrigOp : (RenameIter - 1)->Def;
500 ValueDFS &Result = *RenameIter;
501 auto *ValInfo = Result.PInfo;
502 // For edge predicates, we can just place the operand in the block before
503 // the terminator. For assume, we have to place it right before the assume
504 // to ensure we dominate all of our uses. Always insert right before the
505 // relevant instruction (terminator, assume), so that we insert in proper
506 // order in the case of multiple predicateinfo in the same block.
507 if (isa<PredicateWithEdge>(ValInfo)) {
508 IRBuilder<> B(getBranchTerminator(ValInfo));
509 Function *IF = Intrinsic::getDeclaration(
510 F.getParent(), Intrinsic::ssa_copy, Op->getType());
512 B.CreateCall(IF, Op, Op->getName() + "." + Twine(Counter++));
513 PredicateMap.insert({PIC, ValInfo});
516 auto *PAssume = dyn_cast<PredicateAssume>(ValInfo);
518 "Should not have gotten here without it being an assume");
519 IRBuilder<> B(PAssume->AssumeInst);
520 Function *IF = Intrinsic::getDeclaration(
521 F.getParent(), Intrinsic::ssa_copy, Op->getType());
522 CallInst *PIC = B.CreateCall(IF, Op);
523 PredicateMap.insert({PIC, ValInfo});
527 return RenameStack.back().Def;
530 // Instead of the standard SSA renaming algorithm, which is O(Number of
531 // instructions), and walks the entire dominator tree, we walk only the defs +
532 // uses. The standard SSA renaming algorithm does not really rely on the
533 // dominator tree except to order the stack push/pops of the renaming stacks, so
534 // that defs end up getting pushed before hitting the correct uses. This does
535 // not require the dominator tree, only the *order* of the dominator tree. The
536 // complete and correct ordering of the defs and uses, in dominator tree is
537 // contained in the DFS numbering of the dominator tree. So we sort the defs and
538 // uses into the DFS ordering, and then just use the renaming stack as per
539 // normal, pushing when we hit a def (which is a predicateinfo instruction),
540 // popping when we are out of the dfs scope for that def, and replacing any uses
541 // with top of stack if it exists. In order to handle liveness without
542 // propagating liveness info, we don't actually insert the predicateinfo
543 // instruction def until we see a use that it would dominate. Once we see such
544 // a use, we materialize the predicateinfo instruction in the right place and
547 // TODO: Use this algorithm to perform fast single-variable renaming in
548 // promotememtoreg and memoryssa.
549 void PredicateInfo::renameUses(SmallPtrSetImpl<Value *> &OpSet) {
550 // Sort OpsToRename since we are going to iterate it.
551 SmallVector<Value *, 8> OpsToRename(OpSet.begin(), OpSet.end());
552 auto Comparator = [&](const Value *A, const Value *B) {
553 return valueComesBefore(OI, A, B);
555 std::sort(OpsToRename.begin(), OpsToRename.end(), Comparator);
556 ValueDFS_Compare Compare(OI);
557 // Compute liveness, and rename in O(uses) per Op.
558 for (auto *Op : OpsToRename) {
559 unsigned Counter = 0;
560 SmallVector<ValueDFS, 16> OrderedUses;
561 const auto &ValueInfo = getValueInfo(Op);
562 // Insert the possible copies into the def/use list.
563 // They will become real copies if we find a real use for them, and never
564 // created otherwise.
565 for (auto &PossibleCopy : ValueInfo.Infos) {
567 // Determine where we are going to place the copy by the copy type.
568 // The predicate info for branches always come first, they will get
569 // materialized in the split block at the top of the block.
570 // The predicate info for assumes will be somewhere in the middle,
571 // it will get materialized in front of the assume.
572 if (const auto *PAssume = dyn_cast<PredicateAssume>(PossibleCopy)) {
573 VD.LocalNum = LN_Middle;
574 DomTreeNode *DomNode = DT.getNode(PAssume->AssumeInst->getParent());
577 VD.DFSIn = DomNode->getDFSNumIn();
578 VD.DFSOut = DomNode->getDFSNumOut();
579 VD.PInfo = PossibleCopy;
580 OrderedUses.push_back(VD);
581 } else if (isa<PredicateWithEdge>(PossibleCopy)) {
582 // If we can only do phi uses, we treat it like it's in the branch
583 // block, and handle it specially. We know that it goes last, and only
584 // dominate phi uses.
585 auto BlockEdge = getBlockEdge(PossibleCopy);
586 if (EdgeUsesOnly.count(BlockEdge)) {
587 VD.LocalNum = LN_Last;
588 auto *DomNode = DT.getNode(BlockEdge.first);
590 VD.DFSIn = DomNode->getDFSNumIn();
591 VD.DFSOut = DomNode->getDFSNumOut();
592 VD.PInfo = PossibleCopy;
594 OrderedUses.push_back(VD);
597 // Otherwise, we are in the split block (even though we perform
598 // insertion in the branch block).
599 // Insert a possible copy at the split block and before the branch.
600 VD.LocalNum = LN_First;
601 auto *DomNode = DT.getNode(BlockEdge.second);
603 VD.DFSIn = DomNode->getDFSNumIn();
604 VD.DFSOut = DomNode->getDFSNumOut();
605 VD.PInfo = PossibleCopy;
606 OrderedUses.push_back(VD);
612 convertUsesToDFSOrdered(Op, OrderedUses);
613 std::sort(OrderedUses.begin(), OrderedUses.end(), Compare);
614 SmallVector<ValueDFS, 8> RenameStack;
615 // For each use, sorted into dfs order, push values and replaces uses with
616 // top of stack, which will represent the reaching def.
617 for (auto &VD : OrderedUses) {
618 // We currently do not materialize copy over copy, but we should decide if
620 bool PossibleCopy = VD.PInfo != nullptr;
621 if (RenameStack.empty()) {
622 DEBUG(dbgs() << "Rename Stack is empty\n");
624 DEBUG(dbgs() << "Rename Stack Top DFS numbers are ("
625 << RenameStack.back().DFSIn << ","
626 << RenameStack.back().DFSOut << ")\n");
629 DEBUG(dbgs() << "Current DFS numbers are (" << VD.DFSIn << ","
630 << VD.DFSOut << ")\n");
632 bool ShouldPush = (VD.Def || PossibleCopy);
633 bool OutOfScope = !stackIsInScope(RenameStack, VD);
634 if (OutOfScope || ShouldPush) {
635 // Sync to our current scope.
636 popStackUntilDFSScope(RenameStack, VD);
638 RenameStack.push_back(VD);
641 // If we get to this point, and the stack is empty we must have a use
642 // with no renaming needed, just skip it.
643 if (RenameStack.empty())
645 // Skip values, only want to rename the uses
646 if (VD.Def || PossibleCopy)
648 if (!DebugCounter::shouldExecute(RenameCounter)) {
649 DEBUG(dbgs() << "Skipping execution due to debug counter\n");
652 ValueDFS &Result = RenameStack.back();
654 // If the possible copy dominates something, materialize our stack up to
655 // this point. This ensures every comparison that affects our operation
656 // ends up with predicateinfo.
658 Result.Def = materializeStack(Counter, RenameStack, Op);
660 DEBUG(dbgs() << "Found replacement " << *Result.Def << " for "
661 << *VD.U->get() << " in " << *(VD.U->getUser()) << "\n");
662 assert(DT.dominates(cast<Instruction>(Result.Def), *VD.U) &&
663 "Predicateinfo def should have dominated this use");
664 VD.U->set(Result.Def);
669 PredicateInfo::ValueInfo &PredicateInfo::getOrCreateValueInfo(Value *Operand) {
670 auto OIN = ValueInfoNums.find(Operand);
671 if (OIN == ValueInfoNums.end()) {
673 ValueInfos.resize(ValueInfos.size() + 1);
674 // This will use the new size and give us a 0 based number of the info
675 auto InsertResult = ValueInfoNums.insert({Operand, ValueInfos.size() - 1});
676 assert(InsertResult.second && "Value info number already existed?");
677 return ValueInfos[InsertResult.first->second];
679 return ValueInfos[OIN->second];
682 const PredicateInfo::ValueInfo &
683 PredicateInfo::getValueInfo(Value *Operand) const {
684 auto OINI = ValueInfoNums.lookup(Operand);
685 assert(OINI != 0 && "Operand was not really in the Value Info Numbers");
686 assert(OINI < ValueInfos.size() &&
687 "Value Info Number greater than size of Value Info Table");
688 return ValueInfos[OINI];
691 PredicateInfo::PredicateInfo(Function &F, DominatorTree &DT,
693 : F(F), DT(DT), AC(AC), OI(&DT) {
694 // Push an empty operand info so that we can detect 0 as not finding one
695 ValueInfos.resize(1);
696 buildPredicateInfo();
699 PredicateInfo::~PredicateInfo() {}
701 void PredicateInfo::verifyPredicateInfo() const {}
703 char PredicateInfoPrinterLegacyPass::ID = 0;
705 PredicateInfoPrinterLegacyPass::PredicateInfoPrinterLegacyPass()
707 initializePredicateInfoPrinterLegacyPassPass(
708 *PassRegistry::getPassRegistry());
711 void PredicateInfoPrinterLegacyPass::getAnalysisUsage(AnalysisUsage &AU) const {
712 AU.setPreservesAll();
713 AU.addRequiredTransitive<DominatorTreeWrapperPass>();
714 AU.addRequired<AssumptionCacheTracker>();
717 bool PredicateInfoPrinterLegacyPass::runOnFunction(Function &F) {
718 auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
719 auto &AC = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
720 auto PredInfo = make_unique<PredicateInfo>(F, DT, AC);
721 PredInfo->print(dbgs());
722 if (VerifyPredicateInfo)
723 PredInfo->verifyPredicateInfo();
727 PreservedAnalyses PredicateInfoPrinterPass::run(Function &F,
728 FunctionAnalysisManager &AM) {
729 auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
730 auto &AC = AM.getResult<AssumptionAnalysis>(F);
731 OS << "PredicateInfo for function: " << F.getName() << "\n";
732 make_unique<PredicateInfo>(F, DT, AC)->print(OS);
734 return PreservedAnalyses::all();
737 /// \brief An assembly annotator class to print PredicateInfo information in
739 class PredicateInfoAnnotatedWriter : public AssemblyAnnotationWriter {
740 friend class PredicateInfo;
741 const PredicateInfo *PredInfo;
744 PredicateInfoAnnotatedWriter(const PredicateInfo *M) : PredInfo(M) {}
746 virtual void emitBasicBlockStartAnnot(const BasicBlock *BB,
747 formatted_raw_ostream &OS) {}
749 virtual void emitInstructionAnnot(const Instruction *I,
750 formatted_raw_ostream &OS) {
751 if (const auto *PI = PredInfo->getPredicateInfoFor(I)) {
752 OS << "; Has predicate info\n";
753 if (const auto *PB = dyn_cast<PredicateBranch>(PI)) {
754 OS << "; branch predicate info { TrueEdge: " << PB->TrueEdge
755 << " Comparison:" << *PB->Condition << " Edge: [";
756 PB->From->printAsOperand(OS);
758 PB->To->printAsOperand(OS);
760 } else if (const auto *PS = dyn_cast<PredicateSwitch>(PI)) {
761 OS << "; switch predicate info { CaseValue: " << *PS->CaseValue
762 << " Switch:" << *PS->Switch << " Edge: [";
763 PS->From->printAsOperand(OS);
765 PS->To->printAsOperand(OS);
767 } else if (const auto *PA = dyn_cast<PredicateAssume>(PI)) {
768 OS << "; assume predicate info {"
769 << " Comparison:" << *PA->Condition << " }\n";
775 void PredicateInfo::print(raw_ostream &OS) const {
776 PredicateInfoAnnotatedWriter Writer(this);
777 F.print(OS, &Writer);
780 void PredicateInfo::dump() const {
781 PredicateInfoAnnotatedWriter Writer(this);
782 F.print(dbgs(), &Writer);
785 PreservedAnalyses PredicateInfoVerifierPass::run(Function &F,
786 FunctionAnalysisManager &AM) {
787 auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
788 auto &AC = AM.getResult<AssumptionAnalysis>(F);
789 make_unique<PredicateInfo>(F, DT, AC)->verifyPredicateInfo();
791 return PreservedAnalyses::all();