1 //===-- BranchProbabilityInfo.cpp - Branch Probability Analysis -----------===//
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 // Loops should be simplified before this analysis.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Analysis/BranchProbabilityInfo.h"
15 #include "llvm/ADT/PostOrderIterator.h"
16 #include "llvm/Analysis/LoopInfo.h"
17 #include "llvm/IR/CFG.h"
18 #include "llvm/IR/Constants.h"
19 #include "llvm/IR/Function.h"
20 #include "llvm/IR/Instructions.h"
21 #include "llvm/IR/LLVMContext.h"
22 #include "llvm/IR/Metadata.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/Support/raw_ostream.h"
28 #define DEBUG_TYPE "branch-prob"
30 INITIALIZE_PASS_BEGIN(BranchProbabilityInfoWrapperPass, "branch-prob",
31 "Branch Probability Analysis", false, true)
32 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
33 INITIALIZE_PASS_END(BranchProbabilityInfoWrapperPass, "branch-prob",
34 "Branch Probability Analysis", false, true)
36 char BranchProbabilityInfoWrapperPass::ID = 0;
38 // Weights are for internal use only. They are used by heuristics to help to
39 // estimate edges' probability. Example:
41 // Using "Loop Branch Heuristics" we predict weights of edges for the
56 // Probability of the edge BB2->BB1 = 124 / (124 + 4) = 0.96875
57 // Probability of the edge BB2->BB3 = 4 / (124 + 4) = 0.03125
58 static const uint32_t LBH_TAKEN_WEIGHT = 124;
59 static const uint32_t LBH_NONTAKEN_WEIGHT = 4;
61 /// \brief Unreachable-terminating branch taken weight.
63 /// This is the weight for a branch being taken to a block that terminates
64 /// (eventually) in unreachable. These are predicted as unlikely as possible.
65 static const uint32_t UR_TAKEN_WEIGHT = 1;
67 /// \brief Unreachable-terminating branch not-taken weight.
69 /// This is the weight for a branch not being taken toward a block that
70 /// terminates (eventually) in unreachable. Such a branch is essentially never
71 /// taken. Set the weight to an absurdly high value so that nested loops don't
72 /// easily subsume it.
73 static const uint32_t UR_NONTAKEN_WEIGHT = 1024*1024 - 1;
75 /// \brief Weight for a branch taken going into a cold block.
77 /// This is the weight for a branch taken toward a block marked
78 /// cold. A block is marked cold if it's postdominated by a
79 /// block containing a call to a cold function. Cold functions
80 /// are those marked with attribute 'cold'.
81 static const uint32_t CC_TAKEN_WEIGHT = 4;
83 /// \brief Weight for a branch not-taken into a cold block.
85 /// This is the weight for a branch not taken toward a block marked
87 static const uint32_t CC_NONTAKEN_WEIGHT = 64;
89 static const uint32_t PH_TAKEN_WEIGHT = 20;
90 static const uint32_t PH_NONTAKEN_WEIGHT = 12;
92 static const uint32_t ZH_TAKEN_WEIGHT = 20;
93 static const uint32_t ZH_NONTAKEN_WEIGHT = 12;
95 static const uint32_t FPH_TAKEN_WEIGHT = 20;
96 static const uint32_t FPH_NONTAKEN_WEIGHT = 12;
98 /// \brief Invoke-terminating normal branch taken weight
100 /// This is the weight for branching to the normal destination of an invoke
101 /// instruction. We expect this to happen most of the time. Set the weight to an
102 /// absurdly high value so that nested loops subsume it.
103 static const uint32_t IH_TAKEN_WEIGHT = 1024 * 1024 - 1;
105 /// \brief Invoke-terminating normal branch not-taken weight.
107 /// This is the weight for branching to the unwind destination of an invoke
108 /// instruction. This is essentially never taken.
109 static const uint32_t IH_NONTAKEN_WEIGHT = 1;
111 /// \brief Calculate edge weights for successors lead to unreachable.
113 /// Predict that a successor which leads necessarily to an
114 /// unreachable-terminated block as extremely unlikely.
115 bool BranchProbabilityInfo::calcUnreachableHeuristics(BasicBlock *BB) {
116 TerminatorInst *TI = BB->getTerminator();
117 if (TI->getNumSuccessors() == 0) {
118 if (isa<UnreachableInst>(TI))
119 PostDominatedByUnreachable.insert(BB);
123 SmallVector<unsigned, 4> UnreachableEdges;
124 SmallVector<unsigned, 4> ReachableEdges;
126 for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
127 if (PostDominatedByUnreachable.count(*I))
128 UnreachableEdges.push_back(I.getSuccessorIndex());
130 ReachableEdges.push_back(I.getSuccessorIndex());
133 // If all successors are in the set of blocks post-dominated by unreachable,
134 // this block is too.
135 if (UnreachableEdges.size() == TI->getNumSuccessors())
136 PostDominatedByUnreachable.insert(BB);
138 // Skip probabilities if this block has a single successor or if all were
140 if (TI->getNumSuccessors() == 1 || UnreachableEdges.empty())
143 // If the terminator is an InvokeInst, check only the normal destination block
144 // as the unwind edge of InvokeInst is also very unlikely taken.
145 if (auto *II = dyn_cast<InvokeInst>(TI))
146 if (PostDominatedByUnreachable.count(II->getNormalDest())) {
147 PostDominatedByUnreachable.insert(BB);
148 // Return false here so that edge weights for InvokeInst could be decided
149 // in calcInvokeHeuristics().
153 if (ReachableEdges.empty()) {
154 BranchProbability Prob(1, UnreachableEdges.size());
155 for (unsigned SuccIdx : UnreachableEdges)
156 setEdgeProbability(BB, SuccIdx, Prob);
160 BranchProbability UnreachableProb(UR_TAKEN_WEIGHT,
161 (UR_TAKEN_WEIGHT + UR_NONTAKEN_WEIGHT) *
162 UnreachableEdges.size());
163 BranchProbability ReachableProb(UR_NONTAKEN_WEIGHT,
164 (UR_TAKEN_WEIGHT + UR_NONTAKEN_WEIGHT) *
165 ReachableEdges.size());
167 for (unsigned SuccIdx : UnreachableEdges)
168 setEdgeProbability(BB, SuccIdx, UnreachableProb);
169 for (unsigned SuccIdx : ReachableEdges)
170 setEdgeProbability(BB, SuccIdx, ReachableProb);
175 // Propagate existing explicit probabilities from either profile data or
176 // 'expect' intrinsic processing.
177 bool BranchProbabilityInfo::calcMetadataWeights(BasicBlock *BB) {
178 TerminatorInst *TI = BB->getTerminator();
179 if (TI->getNumSuccessors() == 1)
181 if (!isa<BranchInst>(TI) && !isa<SwitchInst>(TI))
184 MDNode *WeightsNode = TI->getMetadata(LLVMContext::MD_prof);
188 // Check that the number of successors is manageable.
189 assert(TI->getNumSuccessors() < UINT32_MAX && "Too many successors");
191 // Ensure there are weights for all of the successors. Note that the first
192 // operand to the metadata node is a name, not a weight.
193 if (WeightsNode->getNumOperands() != TI->getNumSuccessors() + 1)
196 // Build up the final weights that will be used in a temporary buffer.
197 // Compute the sum of all weights to later decide whether they need to
198 // be scaled to fit in 32 bits.
199 uint64_t WeightSum = 0;
200 SmallVector<uint32_t, 2> Weights;
201 Weights.reserve(TI->getNumSuccessors());
202 for (unsigned i = 1, e = WeightsNode->getNumOperands(); i != e; ++i) {
203 ConstantInt *Weight =
204 mdconst::dyn_extract<ConstantInt>(WeightsNode->getOperand(i));
207 assert(Weight->getValue().getActiveBits() <= 32 &&
208 "Too many bits for uint32_t");
209 Weights.push_back(Weight->getZExtValue());
210 WeightSum += Weights.back();
212 assert(Weights.size() == TI->getNumSuccessors() && "Checked above");
214 // If the sum of weights does not fit in 32 bits, scale every weight down
216 uint64_t ScalingFactor =
217 (WeightSum > UINT32_MAX) ? WeightSum / UINT32_MAX + 1 : 1;
220 for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) {
221 Weights[i] /= ScalingFactor;
222 WeightSum += Weights[i];
225 if (WeightSum == 0) {
226 for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
227 setEdgeProbability(BB, i, {1, e});
229 for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
230 setEdgeProbability(BB, i, {Weights[i], static_cast<uint32_t>(WeightSum)});
233 assert(WeightSum <= UINT32_MAX &&
234 "Expected weights to scale down to 32 bits");
239 /// \brief Calculate edge weights for edges leading to cold blocks.
241 /// A cold block is one post-dominated by a block with a call to a
242 /// cold function. Those edges are unlikely to be taken, so we give
243 /// them relatively low weight.
245 /// Return true if we could compute the weights for cold edges.
246 /// Return false, otherwise.
247 bool BranchProbabilityInfo::calcColdCallHeuristics(BasicBlock *BB) {
248 TerminatorInst *TI = BB->getTerminator();
249 if (TI->getNumSuccessors() == 0)
252 // Determine which successors are post-dominated by a cold block.
253 SmallVector<unsigned, 4> ColdEdges;
254 SmallVector<unsigned, 4> NormalEdges;
255 for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I)
256 if (PostDominatedByColdCall.count(*I))
257 ColdEdges.push_back(I.getSuccessorIndex());
259 NormalEdges.push_back(I.getSuccessorIndex());
261 // If all successors are in the set of blocks post-dominated by cold calls,
262 // this block is in the set post-dominated by cold calls.
263 if (ColdEdges.size() == TI->getNumSuccessors())
264 PostDominatedByColdCall.insert(BB);
266 // Otherwise, if the block itself contains a cold function, add it to the
267 // set of blocks postdominated by a cold call.
268 assert(!PostDominatedByColdCall.count(BB));
269 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
270 if (CallInst *CI = dyn_cast<CallInst>(I))
271 if (CI->hasFnAttr(Attribute::Cold)) {
272 PostDominatedByColdCall.insert(BB);
277 // Skip probabilities if this block has a single successor.
278 if (TI->getNumSuccessors() == 1 || ColdEdges.empty())
281 if (NormalEdges.empty()) {
282 BranchProbability Prob(1, ColdEdges.size());
283 for (unsigned SuccIdx : ColdEdges)
284 setEdgeProbability(BB, SuccIdx, Prob);
288 BranchProbability ColdProb(CC_TAKEN_WEIGHT,
289 (CC_TAKEN_WEIGHT + CC_NONTAKEN_WEIGHT) *
291 BranchProbability NormalProb(CC_NONTAKEN_WEIGHT,
292 (CC_TAKEN_WEIGHT + CC_NONTAKEN_WEIGHT) *
295 for (unsigned SuccIdx : ColdEdges)
296 setEdgeProbability(BB, SuccIdx, ColdProb);
297 for (unsigned SuccIdx : NormalEdges)
298 setEdgeProbability(BB, SuccIdx, NormalProb);
303 // Calculate Edge Weights using "Pointer Heuristics". Predict a comparsion
304 // between two pointer or pointer and NULL will fail.
305 bool BranchProbabilityInfo::calcPointerHeuristics(BasicBlock *BB) {
306 BranchInst * BI = dyn_cast<BranchInst>(BB->getTerminator());
307 if (!BI || !BI->isConditional())
310 Value *Cond = BI->getCondition();
311 ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
312 if (!CI || !CI->isEquality())
315 Value *LHS = CI->getOperand(0);
317 if (!LHS->getType()->isPointerTy())
320 assert(CI->getOperand(1)->getType()->isPointerTy());
322 // p != 0 -> isProb = true
323 // p == 0 -> isProb = false
324 // p != q -> isProb = true
325 // p == q -> isProb = false;
326 unsigned TakenIdx = 0, NonTakenIdx = 1;
327 bool isProb = CI->getPredicate() == ICmpInst::ICMP_NE;
329 std::swap(TakenIdx, NonTakenIdx);
331 BranchProbability TakenProb(PH_TAKEN_WEIGHT,
332 PH_TAKEN_WEIGHT + PH_NONTAKEN_WEIGHT);
333 setEdgeProbability(BB, TakenIdx, TakenProb);
334 setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
338 // Calculate Edge Weights using "Loop Branch Heuristics". Predict backedges
339 // as taken, exiting edges as not-taken.
340 bool BranchProbabilityInfo::calcLoopBranchHeuristics(BasicBlock *BB,
341 const LoopInfo &LI) {
342 Loop *L = LI.getLoopFor(BB);
346 SmallVector<unsigned, 8> BackEdges;
347 SmallVector<unsigned, 8> ExitingEdges;
348 SmallVector<unsigned, 8> InEdges; // Edges from header to the loop.
350 for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
351 if (!L->contains(*I))
352 ExitingEdges.push_back(I.getSuccessorIndex());
353 else if (L->getHeader() == *I)
354 BackEdges.push_back(I.getSuccessorIndex());
356 InEdges.push_back(I.getSuccessorIndex());
359 if (BackEdges.empty() && ExitingEdges.empty())
362 // Collect the sum of probabilities of back-edges/in-edges/exiting-edges, and
363 // normalize them so that they sum up to one.
364 SmallVector<BranchProbability, 4> Probs(3, BranchProbability::getZero());
365 unsigned Denom = (BackEdges.empty() ? 0 : LBH_TAKEN_WEIGHT) +
366 (InEdges.empty() ? 0 : LBH_TAKEN_WEIGHT) +
367 (ExitingEdges.empty() ? 0 : LBH_NONTAKEN_WEIGHT);
368 if (!BackEdges.empty())
369 Probs[0] = BranchProbability(LBH_TAKEN_WEIGHT, Denom);
370 if (!InEdges.empty())
371 Probs[1] = BranchProbability(LBH_TAKEN_WEIGHT, Denom);
372 if (!ExitingEdges.empty())
373 Probs[2] = BranchProbability(LBH_NONTAKEN_WEIGHT, Denom);
375 if (uint32_t numBackEdges = BackEdges.size()) {
376 auto Prob = Probs[0] / numBackEdges;
377 for (unsigned SuccIdx : BackEdges)
378 setEdgeProbability(BB, SuccIdx, Prob);
381 if (uint32_t numInEdges = InEdges.size()) {
382 auto Prob = Probs[1] / numInEdges;
383 for (unsigned SuccIdx : InEdges)
384 setEdgeProbability(BB, SuccIdx, Prob);
387 if (uint32_t numExitingEdges = ExitingEdges.size()) {
388 auto Prob = Probs[2] / numExitingEdges;
389 for (unsigned SuccIdx : ExitingEdges)
390 setEdgeProbability(BB, SuccIdx, Prob);
396 bool BranchProbabilityInfo::calcZeroHeuristics(BasicBlock *BB) {
397 BranchInst * BI = dyn_cast<BranchInst>(BB->getTerminator());
398 if (!BI || !BI->isConditional())
401 Value *Cond = BI->getCondition();
402 ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
406 Value *RHS = CI->getOperand(1);
407 ConstantInt *CV = dyn_cast<ConstantInt>(RHS);
411 // If the LHS is the result of AND'ing a value with a single bit bitmask,
412 // we don't have information about probabilities.
413 if (Instruction *LHS = dyn_cast<Instruction>(CI->getOperand(0)))
414 if (LHS->getOpcode() == Instruction::And)
415 if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(LHS->getOperand(1)))
416 if (AndRHS->getUniqueInteger().isPowerOf2())
421 switch (CI->getPredicate()) {
422 case CmpInst::ICMP_EQ:
423 // X == 0 -> Unlikely
426 case CmpInst::ICMP_NE:
430 case CmpInst::ICMP_SLT:
434 case CmpInst::ICMP_SGT:
441 } else if (CV->isOne() && CI->getPredicate() == CmpInst::ICMP_SLT) {
442 // InstCombine canonicalizes X <= 0 into X < 1.
443 // X <= 0 -> Unlikely
445 } else if (CV->isAllOnesValue()) {
446 switch (CI->getPredicate()) {
447 case CmpInst::ICMP_EQ:
448 // X == -1 -> Unlikely
451 case CmpInst::ICMP_NE:
455 case CmpInst::ICMP_SGT:
456 // InstCombine canonicalizes X >= 0 into X > -1.
467 unsigned TakenIdx = 0, NonTakenIdx = 1;
470 std::swap(TakenIdx, NonTakenIdx);
472 BranchProbability TakenProb(ZH_TAKEN_WEIGHT,
473 ZH_TAKEN_WEIGHT + ZH_NONTAKEN_WEIGHT);
474 setEdgeProbability(BB, TakenIdx, TakenProb);
475 setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
479 bool BranchProbabilityInfo::calcFloatingPointHeuristics(BasicBlock *BB) {
480 BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator());
481 if (!BI || !BI->isConditional())
484 Value *Cond = BI->getCondition();
485 FCmpInst *FCmp = dyn_cast<FCmpInst>(Cond);
490 if (FCmp->isEquality()) {
491 // f1 == f2 -> Unlikely
492 // f1 != f2 -> Likely
493 isProb = !FCmp->isTrueWhenEqual();
494 } else if (FCmp->getPredicate() == FCmpInst::FCMP_ORD) {
497 } else if (FCmp->getPredicate() == FCmpInst::FCMP_UNO) {
504 unsigned TakenIdx = 0, NonTakenIdx = 1;
507 std::swap(TakenIdx, NonTakenIdx);
509 BranchProbability TakenProb(FPH_TAKEN_WEIGHT,
510 FPH_TAKEN_WEIGHT + FPH_NONTAKEN_WEIGHT);
511 setEdgeProbability(BB, TakenIdx, TakenProb);
512 setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
516 bool BranchProbabilityInfo::calcInvokeHeuristics(BasicBlock *BB) {
517 InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator());
521 BranchProbability TakenProb(IH_TAKEN_WEIGHT,
522 IH_TAKEN_WEIGHT + IH_NONTAKEN_WEIGHT);
523 setEdgeProbability(BB, 0 /*Index for Normal*/, TakenProb);
524 setEdgeProbability(BB, 1 /*Index for Unwind*/, TakenProb.getCompl());
528 void BranchProbabilityInfo::releaseMemory() {
532 void BranchProbabilityInfo::print(raw_ostream &OS) const {
533 OS << "---- Branch Probabilities ----\n";
534 // We print the probabilities from the last function the analysis ran over,
535 // or the function it is currently running over.
536 assert(LastF && "Cannot print prior to running over a function");
537 for (const auto &BI : *LastF) {
538 for (succ_const_iterator SI = succ_begin(&BI), SE = succ_end(&BI); SI != SE;
540 printEdgeProbability(OS << " ", &BI, *SI);
545 bool BranchProbabilityInfo::
546 isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const {
547 // Hot probability is at least 4/5 = 80%
548 // FIXME: Compare against a static "hot" BranchProbability.
549 return getEdgeProbability(Src, Dst) > BranchProbability(4, 5);
552 BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB) const {
553 auto MaxProb = BranchProbability::getZero();
554 BasicBlock *MaxSucc = nullptr;
556 for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
557 BasicBlock *Succ = *I;
558 auto Prob = getEdgeProbability(BB, Succ);
559 if (Prob > MaxProb) {
565 // Hot probability is at least 4/5 = 80%
566 if (MaxProb > BranchProbability(4, 5))
572 /// Get the raw edge probability for the edge. If can't find it, return a
573 /// default probability 1/N where N is the number of successors. Here an edge is
574 /// specified using PredBlock and an
575 /// index to the successors.
577 BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
578 unsigned IndexInSuccessors) const {
579 auto I = Probs.find(std::make_pair(Src, IndexInSuccessors));
581 if (I != Probs.end())
585 static_cast<uint32_t>(std::distance(succ_begin(Src), succ_end(Src)))};
589 BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
590 succ_const_iterator Dst) const {
591 return getEdgeProbability(Src, Dst.getSuccessorIndex());
594 /// Get the raw edge probability calculated for the block pair. This returns the
595 /// sum of all raw edge probabilities from Src to Dst.
597 BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
598 const BasicBlock *Dst) const {
599 auto Prob = BranchProbability::getZero();
600 bool FoundProb = false;
601 for (succ_const_iterator I = succ_begin(Src), E = succ_end(Src); I != E; ++I)
603 auto MapI = Probs.find(std::make_pair(Src, I.getSuccessorIndex()));
604 if (MapI != Probs.end()) {
606 Prob += MapI->second;
609 uint32_t succ_num = std::distance(succ_begin(Src), succ_end(Src));
610 return FoundProb ? Prob : BranchProbability(1, succ_num);
613 /// Set the edge probability for a given edge specified by PredBlock and an
614 /// index to the successors.
615 void BranchProbabilityInfo::setEdgeProbability(const BasicBlock *Src,
616 unsigned IndexInSuccessors,
617 BranchProbability Prob) {
618 Probs[std::make_pair(Src, IndexInSuccessors)] = Prob;
619 DEBUG(dbgs() << "set edge " << Src->getName() << " -> " << IndexInSuccessors
620 << " successor probability to " << Prob << "\n");
624 BranchProbabilityInfo::printEdgeProbability(raw_ostream &OS,
625 const BasicBlock *Src,
626 const BasicBlock *Dst) const {
628 const BranchProbability Prob = getEdgeProbability(Src, Dst);
629 OS << "edge " << Src->getName() << " -> " << Dst->getName()
630 << " probability is " << Prob
631 << (isEdgeHot(Src, Dst) ? " [HOT edge]\n" : "\n");
636 void BranchProbabilityInfo::calculate(Function &F, const LoopInfo& LI) {
637 DEBUG(dbgs() << "---- Branch Probability Info : " << F.getName()
639 LastF = &F; // Store the last function we ran on for printing.
640 assert(PostDominatedByUnreachable.empty());
641 assert(PostDominatedByColdCall.empty());
643 // Walk the basic blocks in post-order so that we can build up state about
644 // the successors of a block iteratively.
645 for (auto BB : post_order(&F.getEntryBlock())) {
646 DEBUG(dbgs() << "Computing probabilities for " << BB->getName() << "\n");
647 if (calcUnreachableHeuristics(BB))
649 if (calcMetadataWeights(BB))
651 if (calcColdCallHeuristics(BB))
653 if (calcLoopBranchHeuristics(BB, LI))
655 if (calcPointerHeuristics(BB))
657 if (calcZeroHeuristics(BB))
659 if (calcFloatingPointHeuristics(BB))
661 calcInvokeHeuristics(BB);
664 PostDominatedByUnreachable.clear();
665 PostDominatedByColdCall.clear();
668 void BranchProbabilityInfoWrapperPass::getAnalysisUsage(
669 AnalysisUsage &AU) const {
670 AU.addRequired<LoopInfoWrapperPass>();
671 AU.setPreservesAll();
674 bool BranchProbabilityInfoWrapperPass::runOnFunction(Function &F) {
675 const LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
676 BPI.calculate(F, LI);
680 void BranchProbabilityInfoWrapperPass::releaseMemory() { BPI.releaseMemory(); }
682 void BranchProbabilityInfoWrapperPass::print(raw_ostream &OS,
683 const Module *) const {