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-rw-r--r--llvm/lib/Analysis/BranchProbabilityInfo.cpp6
-rw-r--r--llvm/lib/CodeGen/BranchFolding.cpp16
-rw-r--r--llvm/lib/CodeGen/IfConversion.cpp155
-rw-r--r--llvm/lib/CodeGen/MIRParser/MIParser.cpp3
-rw-r--r--llvm/lib/CodeGen/MIRPrinter.cpp4
-rw-r--r--llvm/lib/CodeGen/MachineBasicBlock.cpp142
-rw-r--r--llvm/lib/CodeGen/MachineBlockPlacement.cpp71
-rw-r--r--llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp82
-rw-r--r--llvm/lib/CodeGen/TailDuplication.cpp6
-rw-r--r--llvm/lib/Support/BranchProbability.cpp20
-rw-r--r--llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp6
-rw-r--r--llvm/lib/Target/ARM/ARMConstantIslandPass.cpp3
-rw-r--r--llvm/lib/Target/ARM/ARMISelLowering.cpp2
-rw-r--r--llvm/lib/Target/Hexagon/HexagonCFGOptimizer.cpp6
-rw-r--r--llvm/lib/Target/Mips/MipsLongBranch.cpp3
15 files changed, 207 insertions, 318 deletions
diff --git a/llvm/lib/Analysis/BranchProbabilityInfo.cpp b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
index f4839469869..6cdf43a06a9 100644
--- a/llvm/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
@@ -647,6 +647,12 @@ getEdgeProbability(const BasicBlock *Src, const BasicBlock *Dst) const {
return BranchProbability(N, D);
}
+BranchProbability
+BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
+ succ_const_iterator Dst) const {
+ return getEdgeProbability(Src, Dst.getSuccessorIndex());
+}
+
raw_ostream &
BranchProbabilityInfo::printEdgeProbability(raw_ostream &OS,
const BasicBlock *Src,
diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index 0b2495cc996..54d92ad67a9 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -1099,13 +1099,19 @@ void BranchFolder::setCommonTailEdgeWeights(MachineBasicBlock &TailMBB) {
if (TailMBB.succ_size() <= 1)
return;
- auto MaxEdgeFreq = *std::max_element(EdgeFreqLs.begin(), EdgeFreqLs.end());
- uint64_t Scale = MaxEdgeFreq.getFrequency() / UINT32_MAX + 1;
+ auto SumEdgeFreq =
+ std::accumulate(EdgeFreqLs.begin(), EdgeFreqLs.end(), BlockFrequency(0))
+ .getFrequency();
auto EdgeFreq = EdgeFreqLs.begin();
- for (auto SuccI = TailMBB.succ_begin(), SuccE = TailMBB.succ_end();
- SuccI != SuccE; ++SuccI, ++EdgeFreq)
- TailMBB.setSuccWeight(SuccI, EdgeFreq->getFrequency() / Scale);
+ if (SumEdgeFreq > 0) {
+ for (auto SuccI = TailMBB.succ_begin(), SuccE = TailMBB.succ_end();
+ SuccI != SuccE; ++SuccI, ++EdgeFreq) {
+ auto Prob = BranchProbability::getBranchProbability(
+ EdgeFreq->getFrequency(), SumEdgeFreq);
+ TailMBB.setSuccProbability(SuccI, Prob);
+ }
+ }
}
//===----------------------------------------------------------------------===//
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp
index 0b2f3ea165f..ff28f95cc33 100644
--- a/llvm/lib/CodeGen/IfConversion.cpp
+++ b/llvm/lib/CodeGen/IfConversion.cpp
@@ -32,6 +32,7 @@
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
+#include <algorithm>
using namespace llvm;
@@ -1151,28 +1152,6 @@ bool IfConverter::IfConvertSimple(BBInfo &BBI, IfcvtKind Kind) {
return true;
}
-/// Scale down weights to fit into uint32_t. NewTrue is the new weight
-/// for successor TrueBB, and NewFalse is the new weight for successor
-/// FalseBB.
-static void ScaleWeights(uint64_t NewTrue, uint64_t NewFalse,
- MachineBasicBlock *MBB,
- const MachineBasicBlock *TrueBB,
- const MachineBasicBlock *FalseBB,
- const MachineBranchProbabilityInfo *MBPI) {
- uint64_t NewMax = (NewTrue > NewFalse) ? NewTrue : NewFalse;
- uint32_t Scale = (NewMax / UINT32_MAX) + 1;
- for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
- SE = MBB->succ_end();
- SI != SE; ++SI) {
- if (*SI == TrueBB)
- MBB->setSuccWeight(SI, (uint32_t)(NewTrue / Scale));
- else if (*SI == FalseBB)
- MBB->setSuccWeight(SI, (uint32_t)(NewFalse / Scale));
- else
- MBB->setSuccWeight(SI, MBPI->getEdgeWeight(MBB, SI) / Scale);
- }
-}
-
/// IfConvertTriangle - If convert a triangle sub-CFG.
///
bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
@@ -1229,16 +1208,14 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
DontKill.clear();
bool HasEarlyExit = CvtBBI->FalseBB != nullptr;
- uint64_t CvtNext = 0, CvtFalse = 0, BBNext = 0, BBCvt = 0, SumWeight = 0;
- uint32_t WeightScale = 0;
+ BranchProbability CvtNext, CvtFalse, BBNext, BBCvt;
if (HasEarlyExit) {
- // Get weights before modifying CvtBBI->BB and BBI.BB.
- CvtNext = MBPI->getEdgeWeight(CvtBBI->BB, NextBBI->BB);
- CvtFalse = MBPI->getEdgeWeight(CvtBBI->BB, CvtBBI->FalseBB);
- BBNext = MBPI->getEdgeWeight(BBI.BB, NextBBI->BB);
- BBCvt = MBPI->getEdgeWeight(BBI.BB, CvtBBI->BB);
- SumWeight = MBPI->getSumForBlock(CvtBBI->BB, WeightScale);
+ // Get probabilities before modifying CvtBBI->BB and BBI.BB.
+ CvtNext = MBPI->getEdgeProbability(CvtBBI->BB, NextBBI->BB);
+ CvtFalse = MBPI->getEdgeProbability(CvtBBI->BB, CvtBBI->FalseBB);
+ BBNext = MBPI->getEdgeProbability(BBI.BB, NextBBI->BB);
+ BBCvt = MBPI->getEdgeProbability(BBI.BB, CvtBBI->BB);
}
if (CvtBBI->BB->pred_size() > 1) {
@@ -1266,22 +1243,24 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
CvtBBI->BrCond.end());
if (TII->ReverseBranchCondition(RevCond))
llvm_unreachable("Unable to reverse branch condition!");
+
+ // Update the edge probability for both CvtBBI->FalseBB and NextBBI.
+ // NewNext = New_Prob(BBI.BB, NextBBI->BB) =
+ // Prob(BBI.BB, NextBBI->BB) +
+ // Prob(BBI.BB, CvtBBI->BB) * Prob(CvtBBI->BB, NextBBI->BB)
+ // NewFalse = New_Prob(BBI.BB, CvtBBI->FalseBB) =
+ // Prob(BBI.BB, CvtBBI->BB) * Prob(CvtBBI->BB, CvtBBI->FalseBB)
+ auto NewTrueBB = getNextBlock(BBI.BB);
+ auto NewNext = BBNext + BBCvt * CvtNext;
+ auto NewTrueBBIter =
+ std::find(BBI.BB->succ_begin(), BBI.BB->succ_end(), NewTrueBB);
+ assert(NewTrueBBIter != BBI.BB->succ_end() &&
+ "NewTrueBB is not a successor of BBI.BB.");
+ BBI.BB->setSuccProbability(NewTrueBBIter, NewNext);
+
+ auto NewFalse = BBCvt * CvtFalse;
TII->InsertBranch(*BBI.BB, CvtBBI->FalseBB, nullptr, RevCond, dl);
- BBI.BB->addSuccessor(CvtBBI->FalseBB);
- // Update the edge weight for both CvtBBI->FalseBB and NextBBI.
- // New_Weight(BBI.BB, NextBBI->BB) =
- // Weight(BBI.BB, NextBBI->BB) * getSumForBlock(CvtBBI->BB) +
- // Weight(BBI.BB, CvtBBI->BB) * Weight(CvtBBI->BB, NextBBI->BB)
- // New_Weight(BBI.BB, CvtBBI->FalseBB) =
- // Weight(BBI.BB, CvtBBI->BB) * Weight(CvtBBI->BB, CvtBBI->FalseBB)
-
- uint64_t NewNext = BBNext * SumWeight + (BBCvt * CvtNext) / WeightScale;
- uint64_t NewFalse = (BBCvt * CvtFalse) / WeightScale;
- // We need to scale down all weights of BBI.BB to fit uint32_t.
- // Here BBI.BB is connected to CvtBBI->FalseBB and will fall through to
- // the next block.
- ScaleWeights(NewNext, NewFalse, BBI.BB, getNextBlock(BBI.BB),
- CvtBBI->FalseBB, MBPI);
+ BBI.BB->addSuccessor(CvtBBI->FalseBB, NewFalse);
}
// Merge in the 'false' block if the 'false' block has no other
@@ -1524,7 +1503,7 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind,
MergeBlocks(BBI, TailBBI);
TailBBI.IsDone = true;
} else {
- BBI.BB->addSuccessor(TailBB);
+ BBI.BB->addSuccessor(TailBB, BranchProbability::getOne());
InsertUncondBranch(BBI.BB, TailBB, TII);
BBI.HasFallThrough = false;
}
@@ -1688,21 +1667,26 @@ void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) {
FromBBI.BB->succ_end());
MachineBasicBlock *NBB = getNextBlock(FromBBI.BB);
MachineBasicBlock *FallThrough = FromBBI.HasFallThrough ? NBB : nullptr;
-
- // The edge weight from ToBBI.BB to FromBBI.BB, which is only needed when
+ // The edge probability from ToBBI.BB to FromBBI.BB, which is only needed when
// AddEdges is true and FromBBI.BB is a successor of ToBBI.BB.
- uint32_t To2FromWeight = 0;
- // WeightScale and SumWeight are for calculating successor probabilities of
- // FromBBI.BB.
- uint32_t WeightScale = 0;
- uint32_t SumWeight = 0;
+ auto To2FromProb = BranchProbability::getZero();
if (AddEdges && ToBBI.BB->isSuccessor(FromBBI.BB)) {
- To2FromWeight = MBPI->getEdgeWeight(ToBBI.BB, FromBBI.BB);
- // Set the edge weight from ToBBI.BB to FromBBI.BB to zero to avoid the edge
- // weight being merged to other edges when this edge is removed later.
- ToBBI.BB->setSuccWeight(
- std::find(ToBBI.BB->succ_begin(), ToBBI.BB->succ_end(), FromBBI.BB), 0);
- SumWeight = MBPI->getSumForBlock(FromBBI.BB, WeightScale);
+ To2FromProb = MBPI->getEdgeProbability(ToBBI.BB, FromBBI.BB);
+ // Set the edge probability from ToBBI.BB to FromBBI.BB to zero to avoid the
+ // edge probability being merged to other edges when this edge is removed
+ // later.
+ ToBBI.BB->setSuccProbability(
+ std::find(ToBBI.BB->succ_begin(), ToBBI.BB->succ_end(), FromBBI.BB),
+ BranchProbability::getZero());
+ }
+
+ if (AddEdges && ToBBI.BB->isSuccessor(FromBBI.BB)) {
+ // Set the edge probability from ToBBI.BB to FromBBI.BB to zero to avoid the
+ // edge probability being merged to other edges when this edge is removed
+ // later.
+ ToBBI.BB->setSuccProbability(
+ std::find(ToBBI.BB->succ_begin(), ToBBI.BB->succ_end(), FromBBI.BB),
+ BranchProbability::getZero());
}
for (unsigned i = 0, e = FromSuccs.size(); i != e; ++i) {
@@ -1711,39 +1695,38 @@ void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) {
if (Succ == FallThrough)
continue;
- uint32_t NewWeight = 0;
+ auto NewProb = BranchProbability::getZero();
if (AddEdges) {
- // Calculate the edge weight for the edge from ToBBI.BB to Succ, which is
- // a portion of the edge weight from FromBBI.BB to Succ. The portion ratio
- // is the edge probability from ToBBI.BB to FromBBI.BB (if FromBBI is a
- // successor of ToBBI.BB. See comment below for excepion).
- NewWeight = MBPI->getEdgeWeight(FromBBI.BB, Succ);
+ // Calculate the edge probability for the edge from ToBBI.BB to Succ,
+ // which is a portion of the edge probability from FromBBI.BB to Succ. The
+ // portion ratio is the edge probability from ToBBI.BB to FromBBI.BB (if
+ // FromBBI is a successor of ToBBI.BB. See comment below for excepion).
+ NewProb = MBPI->getEdgeProbability(FromBBI.BB, Succ);
- // To2FromWeight is 0 when FromBBI.BB is not a successor of ToBBI.BB. This
+ // To2FromProb is 0 when FromBBI.BB is not a successor of ToBBI.BB. This
// only happens when if-converting a diamond CFG and FromBBI.BB is the
// tail BB. In this case FromBBI.BB post-dominates ToBBI.BB and hence we
- // could just use the weights on FromBBI.BB's out-edges when adding new
- // successors.
- if (To2FromWeight > 0) {
- BranchProbability Prob(NewWeight / WeightScale, SumWeight);
- NewWeight = Prob.scale(To2FromWeight);
- }
+ // could just use the probabilities on FromBBI.BB's out-edges when adding
+ // new successors.
+ if (!To2FromProb.isZero())
+ NewProb *= To2FromProb;
}
FromBBI.BB->removeSuccessor(Succ);
if (AddEdges) {
- // If the edge from ToBBI.BB to Succ already exists, update the weight of
- // this edge by adding NewWeight to it. An example is shown below, in
- // which A is ToBBI.BB and B is FromBBI.BB. In this case we don't have to
- // set C as A's successor as it already is. We only need to update the
- // edge weight on A->C. Note that B will not be immediately removed from
- // A's successors. It is possible that B->D is not removed either if D is
- // a fallthrough of B. Later the edge A->D (generated here) and B->D will
- // be combined into one edge. To maintain correct edge weight of this
- // combined edge, we need to set the edge weight of A->B to zero, which is
- // already done above. The edge weight on A->D is calculated by scaling
- // the original weight on A->B by the probability of B->D.
+ // If the edge from ToBBI.BB to Succ already exists, update the
+ // probability of this edge by adding NewWeight to it. An example is shown
+ // below, in which A is ToBBI.BB and B is FromBBI.BB. In this case we
+ // don't have to set C as A's successor as it already is. We only need to
+ // update the edge probability on A->C. Note that B will not be
+ // immediately removed from A's successors. It is possible that B->D is
+ // not removed either if D is a fallthrough of B. Later the edge A->D
+ // (generated here) and B->D will be combined into one edge. To maintain
+ // correct edge probability of this combined edge, we need to set the edge
+ // probability of A->B to zero, which is already done above. The edge
+ // probability on A->D is calculated by scaling the original probability
+ // on A->B by the probability of B->D.
//
// Before ifcvt: After ifcvt (assume B->D is kept):
//
@@ -1755,11 +1738,11 @@ void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) {
// C D C D
//
if (ToBBI.BB->isSuccessor(Succ))
- ToBBI.BB->setSuccWeight(
+ ToBBI.BB->setSuccProbability(
std::find(ToBBI.BB->succ_begin(), ToBBI.BB->succ_end(), Succ),
- MBPI->getEdgeWeight(ToBBI.BB, Succ) + NewWeight);
+ MBPI->getEdgeProbability(ToBBI.BB, Succ) + NewProb);
else
- ToBBI.BB->addSuccessor(Succ, NewWeight);
+ ToBBI.BB->addSuccessor(Succ, NewProb);
}
}
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 5a8e96df760..c9c2d62cec3 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -459,8 +459,9 @@ bool MIParser::parseBasicBlockSuccessors(MachineBasicBlock &MBB) {
if (expectAndConsume(MIToken::rparen))
return true;
}
- MBB.addSuccessor(SuccMBB, Weight);
+ MBB.addSuccessor(SuccMBB, BranchProbability::getRaw(Weight));
} while (consumeIfPresent(MIToken::comma));
+ MBB.normalizeSuccProbs();
return false;
}
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index 0be7807064f..175cb0d5143 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -461,8 +461,8 @@ void MIPrinter::print(const MachineBasicBlock &MBB) {
if (I != MBB.succ_begin())
OS << ", ";
printMBBReference(**I);
- if (MBB.hasSuccessorWeights())
- OS << '(' << MBB.getSuccWeight(I) << ')';
+ if (MBB.hasSuccessorProbabilities())
+ OS << '(' << MBB.getSuccProbability(I) << ')';
}
OS << "\n";
HasLineAttributes = true;
diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 602b75182fc..c9c6a9d6246 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -319,8 +319,8 @@ void MachineBasicBlock::print(raw_ostream &OS, ModuleSlotTracker &MST,
OS << " Successors according to CFG:";
for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) {
OS << " BB#" << (*SI)->getNumber();
- if (!Weights.empty())
- OS << '(' << *getWeightIterator(SI) << ')';
+ if (!Probs.empty())
+ OS << '(' << *getProbabilityIterator(SI) << ')';
}
OS << '\n';
}
@@ -506,34 +506,16 @@ void MachineBasicBlock::updateTerminator() {
}
}
-void MachineBasicBlock::addSuccessor(MachineBasicBlock *Succ, uint32_t Weight) {
- // Weight list is either empty (if successor list isn't empty, this means
- // disabled optimization) or has the same size as successor list.
- if (!(Weights.empty() && !Successors.empty()))
- Weights.push_back(Weight);
- Successors.push_back(Succ);
- Succ->addPredecessor(this);
-}
-
-void MachineBasicBlock::addSuccessorWithoutWeight(MachineBasicBlock *Succ) {
- // We need to make sure weight list is either empty or has the same size of
- // successor list. When this function is called, we can safely delete all
- // weight in the list.
- Weights.clear();
- Successors.push_back(Succ);
- Succ->addPredecessor(this);
-}
-
void MachineBasicBlock::addSuccessor(MachineBasicBlock *Succ,
BranchProbability Prob) {
// Probability list is either empty (if successor list isn't empty, this means
// disabled optimization) or has the same size as successor list.
if (!(Probs.empty() && !Successors.empty())) {
+ assert((Probs.empty() || (Prob.isUnknown() && Probs.back().isUnknown()) ||
+ (!Prob.isUnknown() && !Probs.back().isUnknown())) &&
+ "Successors with both known and unknwon probabilities are not "
+ "allowed.");
Probs.push_back(Prob);
- // FIXME: Temporarily use the numerator of the probability to represent edge
- // weight. This will be removed once all weight-version interfaces in MBB
- // are replaced with probability-version interfaces.
- Weights.push_back(Prob.getNumerator());
}
Successors.push_back(Succ);
Succ->addPredecessor(this);
@@ -544,7 +526,6 @@ void MachineBasicBlock::addSuccessorWithoutProb(MachineBasicBlock *Succ) {
// of successor list. When this function is called, we can safely delete all
// probability in the list.
Probs.clear();
- Weights.clear();
Successors.push_back(Succ);
Succ->addPredecessor(this);
}
@@ -558,23 +539,12 @@ MachineBasicBlock::succ_iterator
MachineBasicBlock::removeSuccessor(succ_iterator I) {
assert(I != Successors.end() && "Not a current successor!");
- // If Weight list is empty it means we don't use it (disabled optimization).
- if (!Weights.empty()) {
- weight_iterator WI = getWeightIterator(I);
- Weights.erase(WI);
- }
-
- // FIXME: Temporarily comment the following code as probabilities are now only
- // used during instruction lowering, but this interface is called in later
- // passes. Uncomment it once all edge weights are replaced with probabilities.
-#if 0
// If probability list is empty it means we don't use it (disabled
// optimization).
if (!Probs.empty()) {
probability_iterator WI = getProbabilityIterator(I);
Probs.erase(WI);
}
-#endif
(*I)->removePredecessor(this);
return Successors.erase(I);
@@ -611,17 +581,12 @@ void MachineBasicBlock::replaceSuccessor(MachineBasicBlock *Old,
}
// New is already a successor.
- // Update its weight instead of adding a duplicate edge.
- if (!Weights.empty())
- *getWeightIterator(NewI) += *getWeightIterator(OldI);
- // FIXME: Temporarily comment the following code as probabilities are now only
- // used during instruction lowering, but this interface is called in later
- // passes. Uncomment it once all edge weights are replaced with probabilities.
-#if 0
// Update its probability instead of adding a duplicate edge.
- if (!Probs.empty())
- *getProbabilityIterator(NewI) += *getProbabilityIterator(OldI);
-#endif
+ if (!Probs.empty()) {
+ auto ProbIter = getProbabilityIterator(NewI);
+ if (!ProbIter->isUnknown())
+ *ProbIter += *getProbabilityIterator(OldI);
+ }
removeSuccessor(OldI);
}
@@ -641,13 +606,14 @@ void MachineBasicBlock::transferSuccessors(MachineBasicBlock *FromMBB) {
while (!FromMBB->succ_empty()) {
MachineBasicBlock *Succ = *FromMBB->succ_begin();
- uint32_t Weight = 0;
- // If Weight list is empty it means we don't use it (disabled optimization).
- if (!FromMBB->Weights.empty())
- Weight = *FromMBB->Weights.begin();
+ // If probability list is empty it means we don't use it (disabled optimization).
+ if (!FromMBB->Probs.empty()) {
+ auto Prob = *FromMBB->Probs.begin();
+ addSuccessor(Succ, Prob);
+ } else
+ addSuccessorWithoutProb(Succ);
- addSuccessor(Succ, Weight);
FromMBB->removeSuccessor(Succ);
}
}
@@ -659,10 +625,11 @@ MachineBasicBlock::transferSuccessorsAndUpdatePHIs(MachineBasicBlock *FromMBB) {
while (!FromMBB->succ_empty()) {
MachineBasicBlock *Succ = *FromMBB->succ_begin();
- uint32_t Weight = 0;
- if (!FromMBB->Weights.empty())
- Weight = *FromMBB->Weights.begin();
- addSuccessor(Succ, Weight);
+ if (!FromMBB->Probs.empty()) {
+ auto Prob = *FromMBB->Probs.begin();
+ addSuccessor(Succ, Prob);
+ } else
+ addSuccessorWithoutProb(Succ);
FromMBB->removeSuccessor(Succ);
// Fix up any PHI nodes in the successor.
@@ -1146,80 +1113,37 @@ MachineBasicBlock::findDebugLoc(instr_iterator MBBI) {
return DL;
}
-/// Return weight of the edge from this block to MBB.
-uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const {
- if (Weights.empty())
- return 0;
-
- return *getWeightIterator(Succ);
-}
-
-/// Return probability of the edge from this block to MBB. If probability list
-/// is empty, return a default probability which is 1/N, where N is the number
-/// of successors. If the probability of the given successor is unknown, then
-/// sum up all known probabilities and return the complement of the sum divided
-/// by the number of unknown probabilities.
+/// Return probability of the edge from this block to MBB.
BranchProbability
MachineBasicBlock::getSuccProbability(const_succ_iterator Succ) const {
- if (Probs.empty())
+ if (Probs.empty() || Probs.back().isUnknown())
return BranchProbability(1, succ_size());
- auto Prob = *getProbabilityIterator(Succ);
- assert(!Prob.isUnknown());
- return Prob;
-}
-
-/// Set successor weight of a given iterator.
-void MachineBasicBlock::setSuccWeight(succ_iterator I, uint32_t Weight) {
- if (Weights.empty())
- return;
- *getWeightIterator(I) = Weight;
+ return *getProbabilityIterator(Succ);
}
/// Set successor probability of a given iterator.
void MachineBasicBlock::setSuccProbability(succ_iterator I,
BranchProbability Prob) {
assert(!Prob.isUnknown());
- if (Probs.empty() || Weights.empty())
+ if (Probs.empty())
return;
*getProbabilityIterator(I) = Prob;
- // FIXME: Temporarily use the numerator of the probability to represent edge
- // weight. This will be removed once all weight-version interfaces in MBB
- // are replaces with probability-version interfaces.
- *getWeightIterator(I) = Prob.getNumerator();
-}
-
-/// Return wight iterator corresonding to the I successor iterator.
-MachineBasicBlock::weight_iterator MachineBasicBlock::
-getWeightIterator(MachineBasicBlock::succ_iterator I) {
- assert(Weights.size() == Successors.size() && "Async weight list!");
- size_t index = std::distance(Successors.begin(), I);
- assert(index < Weights.size() && "Not a current successor!");
- return Weights.begin() + index;
}
-/// Return wight iterator corresonding to the I successor iterator.
-MachineBasicBlock::const_weight_iterator MachineBasicBlock::
-getWeightIterator(MachineBasicBlock::const_succ_iterator I) const {
- assert(Weights.size() == Successors.size() && "Async weight list!");
- const size_t index = std::distance(Successors.begin(), I);
- assert(index < Weights.size() && "Not a current successor!");
- return Weights.begin() + index;
-}
-
-/// Return probability iterator corresonding to the I successor iterator.
-MachineBasicBlock::probability_iterator
-MachineBasicBlock::getProbabilityIterator(MachineBasicBlock::succ_iterator I) {
+/// Return probability iterator corresonding to the I successor iterator
+MachineBasicBlock::const_probability_iterator
+MachineBasicBlock::getProbabilityIterator(
+ MachineBasicBlock::const_succ_iterator I) const {
assert(Probs.size() == Successors.size() && "Async probability list!");
const size_t index = std::distance(Successors.begin(), I);
assert(index < Probs.size() && "Not a current successor!");
return Probs.begin() + index;
}
-/// Return probability iterator corresonding to the I successor iterator
-MachineBasicBlock::const_probability_iterator
-MachineBasicBlock::getProbabilityIterator(
- MachineBasicBlock::const_succ_iterator I) const {
+/// Return probability iterator corresonding to the I successor iterator.
+MachineBasicBlock::probability_iterator
+MachineBasicBlock::getProbabilityIterator(MachineBasicBlock::succ_iterator I) {
assert(Probs.size() == Successors.size() && "Async probability list!");
const size_t index = std::distance(Successors.begin(), I);
assert(index < Probs.size() && "Not a current successor!");
diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
index fba33eb93d5..fcddf346cf6 100644
--- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
@@ -380,19 +380,11 @@ MachineBlockPlacement::selectBestSuccessor(MachineBasicBlock *BB,
const BranchProbability HotProb(4, 5); // 80%
MachineBasicBlock *BestSucc = nullptr;
- // FIXME: Due to the performance of the probability and weight routines in
- // the MBPI analysis, we manually compute probabilities using the edge
- // weights. This is suboptimal as it means that the somewhat subtle
- // definition of edge weight semantics is encoded here as well. We should
- // improve the MBPI interface to efficiently support query patterns such as
- // this.
- uint32_t BestWeight = 0;
- uint32_t WeightScale = 0;
- uint32_t SumWeight = MBPI->getSumForBlock(BB, WeightScale);
-
- // Adjust sum of weights by excluding weights on edges pointing to blocks that
- // is either not in BlockFilter or is already in the current chain. Consider
- // the following CFG:
+ auto BestProb = BranchProbability::getZero();
+
+ // Adjust edge probabilities by excluding edges pointing to blocks that is
+ // either not in BlockFilter or is already in the current chain. Consider the
+ // following CFG:
//
// --->A
// | / \
@@ -406,7 +398,7 @@ MachineBlockPlacement::selectBestSuccessor(MachineBasicBlock *BB,
// HotProb). If we exclude E that is not in BlockFilter when calculating the
// probability of C->D, D will be selected and we will get A C D B as the
// layout of this loop.
- uint32_t AdjustedSumWeight = SumWeight;
+ auto AdjustedSumProb = BranchProbability::getOne();
SmallVector<MachineBasicBlock *, 4> Successors;
for (MachineBasicBlock *Succ : BB->successors()) {
bool SkipSucc = false;
@@ -424,15 +416,20 @@ MachineBlockPlacement::selectBestSuccessor(MachineBasicBlock *BB,
}
}
if (SkipSucc)
- AdjustedSumWeight -= MBPI->getEdgeWeight(BB, Succ) / WeightScale;
+ AdjustedSumProb -= MBPI->getEdgeProbability(BB, Succ);
else
Successors.push_back(Succ);
}
DEBUG(dbgs() << "Attempting merge from: " << getBlockName(BB) << "\n");
for (MachineBasicBlock *Succ : Successors) {
- uint32_t SuccWeight = MBPI->getEdgeWeight(BB, Succ);
- BranchProbability SuccProb(SuccWeight / WeightScale, AdjustedSumWeight);
+ BranchProbability SuccProb;
+ uint32_t SuccProbN = MBPI->getEdgeProbability(BB, Succ).getNumerator();
+ uint32_t SuccProbD = AdjustedSumProb.getNumerator();
+ if (SuccProbN >= SuccProbD)
+ SuccProb = BranchProbability::getOne();
+ else
+ SuccProb = BranchProbability(SuccProbN, SuccProbD);
// If we outline optional branches, look whether Succ is unavoidable, i.e.
// dominates all terminators of the MachineFunction. If it does, other
@@ -470,7 +467,7 @@ MachineBlockPlacement::selectBestSuccessor(MachineBasicBlock *BB,
// Make sure that a hot successor doesn't have a globally more
// important predecessor.
- BranchProbability RealSuccProb(SuccWeight / WeightScale, SumWeight);
+ auto RealSuccProb = MBPI->getEdgeProbability(BB, Succ);
BlockFrequency CandidateEdgeFreq =
MBFI->getBlockFreq(BB) * RealSuccProb * HotProb.getCompl();
bool BadCFGConflict = false;
@@ -496,10 +493,10 @@ MachineBlockPlacement::selectBestSuccessor(MachineBasicBlock *BB,
<< " (prob)"
<< (SuccChain.LoopPredecessors != 0 ? " (CFG break)" : "")
<< "\n");
- if (BestSucc && BestWeight >= SuccWeight)
+ if (BestSucc && BestProb >= SuccProb)
continue;
BestSucc = Succ;
- BestWeight = SuccWeight;
+ BestProb = SuccProb;
}
return BestSucc;
}
@@ -728,11 +725,6 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
MachineBasicBlock *OldExitingBB = ExitingBB;
BlockFrequency OldBestExitEdgeFreq = BestExitEdgeFreq;
bool HasLoopingSucc = false;
- // FIXME: Due to the performance of the probability and weight routines in
- // the MBPI analysis, we use the internal weights and manually compute the
- // probabilities to avoid quadratic behavior.
- uint32_t WeightScale = 0;
- uint32_t SumWeight = MBPI->getSumForBlock(MBB, WeightScale);
for (MachineBasicBlock *Succ : MBB->successors()) {
if (Succ->isEHPad())
continue;
@@ -746,10 +738,10 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
continue;
}
- uint32_t SuccWeight = MBPI->getEdgeWeight(MBB, Succ);
+ auto SuccProb = MBPI->getEdgeProbability(MBB, Succ);
if (LoopBlockSet.count(Succ)) {
DEBUG(dbgs() << " looping: " << getBlockName(MBB) << " -> "
- << getBlockName(Succ) << " (" << SuccWeight << ")\n");
+ << getBlockName(Succ) << " (" << SuccProb << ")\n");
HasLoopingSucc = true;
continue;
}
@@ -761,7 +753,6 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
BlocksExitingToOuterLoop.insert(MBB);
}
- BranchProbability SuccProb(SuccWeight / WeightScale, SumWeight);
BlockFrequency ExitEdgeFreq = MBFI->getBlockFreq(MBB) * SuccProb;
DEBUG(dbgs() << " exiting: " << getBlockName(MBB) << " -> "
<< getBlockName(Succ) << " [L:" << SuccLoopDepth << "] (";
@@ -904,21 +895,17 @@ void MachineBlockPlacement::rotateLoopWithProfile(
// edge from the tail of the loop chain.
SmallVector<std::pair<MachineBasicBlock *, BlockFrequency>, 4> ExitsWithFreq;
for (auto BB : LoopChain) {
- uint32_t LargestExitEdgeWeight = 0;
+ auto LargestExitEdgeProb = BranchProbability::getZero();
for (auto *Succ : BB->successors()) {
BlockChain *SuccChain = BlockToChain[Succ];
if (!LoopBlockSet.count(Succ) &&
(!SuccChain || Succ == *SuccChain->begin())) {
- uint32_t SuccWeight = MBPI->getEdgeWeight(BB, Succ);
- LargestExitEdgeWeight = std::max(LargestExitEdgeWeight, SuccWeight);
+ auto SuccProb = MBPI->getEdgeProbability(BB, Succ);
+ LargestExitEdgeProb = std::max(LargestExitEdgeProb, SuccProb);
}
}
- if (LargestExitEdgeWeight > 0) {
- uint32_t WeightScale = 0;
- uint32_t SumWeight = MBPI->getSumForBlock(BB, WeightScale);
- auto ExitFreq =
- MBFI->getBlockFreq(BB) *
- BranchProbability(LargestExitEdgeWeight / WeightScale, SumWeight);
+ if (LargestExitEdgeProb > BranchProbability::getZero()) {
+ auto ExitFreq = MBFI->getBlockFreq(BB) * LargestExitEdgeProb;
ExitsWithFreq.emplace_back(BB, ExitFreq);
}
}
@@ -1290,14 +1277,16 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) {
}
// If PrevBB has a two-way branch, try to re-order the branches
- // such that we branch to the successor with higher weight first.
+ // such that we branch to the successor with higher probability first.
if (TBB && !Cond.empty() && FBB &&
- MBPI->getEdgeWeight(PrevBB, FBB) > MBPI->getEdgeWeight(PrevBB, TBB) &&
+ MBPI->getEdgeProbability(PrevBB, FBB) >
+ MBPI->getEdgeProbability(PrevBB, TBB) &&
!TII->ReverseBranchCondition(Cond)) {
DEBUG(dbgs() << "Reverse order of the two branches: "
<< getBlockName(PrevBB) << "\n");
- DEBUG(dbgs() << " Edge weight: " << MBPI->getEdgeWeight(PrevBB, FBB)
- << " vs " << MBPI->getEdgeWeight(PrevBB, TBB) << "\n");
+ DEBUG(dbgs() << " Edge probability: "
+ << MBPI->getEdgeProbability(PrevBB, FBB) << " vs "
+ << MBPI->getEdgeProbability(PrevBB, TBB) << "\n");
DebugLoc dl; // FIXME: this is nowhere
TII->RemoveBranch(*PrevBB);
TII->InsertBranch(*PrevBB, FBB, TBB, Cond, dl);
diff --git a/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp b/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp
index 6fbc2be7048..5478dcba261 100644
--- a/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp
+++ b/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp
@@ -28,91 +28,61 @@ char MachineBranchProbabilityInfo::ID = 0;
void MachineBranchProbabilityInfo::anchor() { }
-uint32_t MachineBranchProbabilityInfo::
-getSumForBlock(const MachineBasicBlock *MBB, uint32_t &Scale) const {
- // First we compute the sum with 64-bits of precision, ensuring that cannot
- // overflow by bounding the number of weights considered. Hopefully no one
- // actually needs 2^32 successors.
- assert(MBB->succ_size() < UINT32_MAX);
- uint64_t Sum = 0;
- Scale = 1;
- for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
- E = MBB->succ_end(); I != E; ++I) {
- uint32_t Weight = getEdgeWeight(MBB, I);
- Sum += Weight;
- }
-
- // If the computed sum fits in 32-bits, we're done.
- if (Sum <= UINT32_MAX)
- return Sum;
+uint32_t MachineBranchProbabilityInfo::getEdgeWeight(
+ const MachineBasicBlock *Src,
+ MachineBasicBlock::const_succ_iterator Dst) const {
+ return Src->getSuccProbability(Dst).getNumerator();
+}
- // Otherwise, compute the scale necessary to cause the weights to fit, and
- // re-sum with that scale applied.
- assert((Sum / UINT32_MAX) < UINT32_MAX);
- Scale = (Sum / UINT32_MAX) + 1;
- Sum = 0;
- for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
- E = MBB->succ_end(); I != E; ++I) {
- uint32_t Weight = getEdgeWeight(MBB, I);
- Sum += Weight / Scale;
- }
- assert(Sum <= UINT32_MAX);
- return Sum;
+uint32_t MachineBranchProbabilityInfo::getEdgeWeight(
+ const MachineBasicBlock *Src, const MachineBasicBlock *Dst) const {
+ // This is a linear search. Try to use the const_succ_iterator version when
+ // possible.
+ return getEdgeWeight(Src, std::find(Src->succ_begin(), Src->succ_end(), Dst));
}
-uint32_t MachineBranchProbabilityInfo::
-getEdgeWeight(const MachineBasicBlock *Src,
- MachineBasicBlock::const_succ_iterator Dst) const {
- uint32_t Weight = Src->getSuccWeight(Dst);
- if (!Weight)
- return DEFAULT_WEIGHT;
- return Weight;
+BranchProbability MachineBranchProbabilityInfo::getEdgeProbability(
+ const MachineBasicBlock *Src,
+ MachineBasicBlock::const_succ_iterator Dst) const {
+ return Src->getSuccProbability(Dst);
}
-uint32_t MachineBranchProbabilityInfo::
-getEdgeWeight(const MachineBasicBlock *Src,
- const MachineBasicBlock *Dst) const {
+BranchProbability MachineBranchProbabilityInfo::getEdgeProbability(
+ const MachineBasicBlock *Src, const MachineBasicBlock *Dst) const {
// This is a linear search. Try to use the const_succ_iterator version when
// possible.
- return getEdgeWeight(Src, std::find(Src->succ_begin(), Src->succ_end(), Dst));
+ return getEdgeProbability(Src,
+ std::find(Src->succ_begin(), Src->succ_end(), Dst));
}
bool
MachineBranchProbabilityInfo::isEdgeHot(const MachineBasicBlock *Src,
const MachineBasicBlock *Dst) const {
// Hot probability is at least 4/5 = 80%
- // FIXME: Compare against a static "hot" BranchProbability.
- return getEdgeProbability(Src, Dst) > BranchProbability(4, 5);
+ static BranchProbability HotProb(4, 5);
+ return getEdgeProbability(Src, Dst) > HotProb;
}
MachineBasicBlock *
MachineBranchProbabilityInfo::getHotSucc(MachineBasicBlock *MBB) const {
- uint32_t MaxWeight = 0;
+ auto MaxProb = BranchProbability::getZero();
MachineBasicBlock *MaxSucc = nullptr;
for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
E = MBB->succ_end(); I != E; ++I) {
- uint32_t Weight = getEdgeWeight(MBB, I);
- if (Weight > MaxWeight) {
- MaxWeight = Weight;
+ auto Prob = getEdgeProbability(MBB, I);
+ if (Prob > MaxProb) {
+ MaxProb = Prob;
MaxSucc = *I;
}
}
- if (getEdgeProbability(MBB, MaxSucc) >= BranchProbability(4, 5))
+ static BranchProbability HotProb(4, 5);
+ if (getEdgeProbability(MBB, MaxSucc) >= HotProb)
return MaxSucc;
return nullptr;
}
-BranchProbability MachineBranchProbabilityInfo::getEdgeProbability(
- const MachineBasicBlock *Src, const MachineBasicBlock *Dst) const {
- uint32_t Scale = 1;
- uint32_t D = getSumForBlock(Src, Scale);
- uint32_t N = getEdgeWeight(Src, Dst) / Scale;
-
- return BranchProbability(N, D);
-}
-
raw_ostream &MachineBranchProbabilityInfo::printEdgeProbability(
raw_ostream &OS, const MachineBasicBlock *Src,
const MachineBasicBlock *Dst) const {
diff --git a/llvm/lib/CodeGen/TailDuplication.cpp b/llvm/lib/CodeGen/TailDuplication.cpp
index ff86dabfac5..1f5b54866ac 100644
--- a/llvm/lib/CodeGen/TailDuplication.cpp
+++ b/llvm/lib/CodeGen/TailDuplication.cpp
@@ -745,12 +745,12 @@ TailDuplicatePass::duplicateSimpleBB(MachineBasicBlock *TailBB,
if (PredTBB)
TII->InsertBranch(*PredBB, PredTBB, PredFBB, PredCond, DebugLoc());
- uint32_t Weight = MBPI->getEdgeWeight(PredBB, TailBB);
+ auto Prob = MBPI->getEdgeProbability(PredBB, TailBB);
PredBB->removeSuccessor(TailBB);
unsigned NumSuccessors = PredBB->succ_size();
assert(NumSuccessors <= 1);
if (NumSuccessors == 0 || *PredBB->succ_begin() != NewTarget)
- PredBB->addSuccessor(NewTarget, Weight);
+ PredBB->addSuccessor(NewTarget, Prob);
TDBBs.push_back(PredBB);
}
@@ -858,7 +858,7 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB,
"TailDuplicate called on block with multiple successors!");
for (MachineBasicBlock::succ_iterator I = TailBB->succ_begin(),
E = TailBB->succ_end(); I != E; ++I)
- PredBB->addSuccessor(*I, MBPI->getEdgeWeight(TailBB, I));
+ PredBB->addSuccessor(*I, MBPI->getEdgeProbability(TailBB, I));
Changed = true;
++NumTailDups;
diff --git a/llvm/lib/Support/BranchProbability.cpp b/llvm/lib/Support/BranchProbability.cpp
index 3b0f6e6f06e..771d02c0aa3 100644
--- a/llvm/lib/Support/BranchProbability.cpp
+++ b/llvm/lib/Support/BranchProbability.cpp
@@ -22,11 +22,14 @@ using namespace llvm;
const uint32_t BranchProbability::D;
raw_ostream &BranchProbability::print(raw_ostream &OS) const {
+ if (isUnknown())
+ return OS << "?%";
+
// Get a percentage rounded to two decimal digits. This avoids
// implementation-defined rounding inside printf.
double Percent = rint(((double)N / D) * 100.0 * 100.0) / 100.0;
- OS << format("0x%08" PRIx32 " / 0x%08" PRIx32 " = %.2f%%", N, D, Percent);
- return OS;
+ return OS << format("0x%08" PRIx32 " / 0x%08" PRIx32 " = %.2f%%", N, D,
+ Percent);
}
void BranchProbability::dump() const { print(dbgs()) << '\n'; }
@@ -43,6 +46,19 @@ BranchProbability::BranchProbability(uint32_t Numerator, uint32_t Denominator) {
}
}
+BranchProbability
+BranchProbability::getBranchProbability(uint64_t Numerator,
+ uint64_t Denominator) {
+ assert(Numerator <= Denominator && "Probability cannot be bigger than 1!");
+ // Scale down Denominator to fit in a 32-bit integer.
+ int Scale = 0;
+ while (Denominator > UINT32_MAX) {
+ Denominator >>= 1;
+ Scale++;
+ }
+ return BranchProbability(Numerator >> Scale, Denominator);
+}
+
// If ConstD is not zero, then replace D by ConstD so that division and modulo
// operations by D can be optimized, in case this function is not inlined by the
// compiler.
diff --git a/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp b/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
index f1b38301790..cdbd1209215 100644
--- a/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
@@ -1570,8 +1570,7 @@ void AMDGPUCFGStructurizer::mergeLooplandBlock(MachineBasicBlock *DstBlk,
insertInstrBefore(DstBlk, AMDGPU::WHILELOOP, DebugLoc());
insertInstrEnd(DstBlk, AMDGPU::ENDLOOP, DebugLoc());
- DstBlk->addSuccessor(LandMBB);
- DstBlk->removeSuccessor(DstBlk);
+ DstBlk->replaceSuccessor(DstBlk, LandMBB);
}
@@ -1666,8 +1665,7 @@ AMDGPUCFGStructurizer::cloneBlockForPredecessor(MachineBasicBlock *MBB,
replaceInstrUseOfBlockWith(PredMBB, MBB, CloneMBB);
//srcBlk, oldBlk, newBlk
- PredMBB->removeSuccessor(MBB);
- PredMBB->addSuccessor(CloneMBB);
+ PredMBB->replaceSuccessor(MBB, CloneMBB);
// add all successor to cloneBlk
cloneSuccessorList(CloneMBB, MBB);
diff --git a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
index 0bf2d374df6..e89757c19ec 100644
--- a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -2274,8 +2274,7 @@ adjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) {
// Update the CFG.
NewBB->addSuccessor(BB);
- JTBB->removeSuccessor(BB);
- JTBB->addSuccessor(NewBB);
+ JTBB->replaceSuccessor(BB, NewBB);
++NumJTInserted;
return NewBB;
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 0cc41812d71..e8f3ab65bdb 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -7346,7 +7346,7 @@ void ARMTargetLowering::EmitSjLjDispatchBlock(MachineInstr *MI,
}
}
- BB->addSuccessor(DispatchBB);
+ BB->addSuccessor(DispatchBB, BranchProbability::getZero());
// Find the invoke call and mark all of the callee-saved registers as
// 'implicit defined' so that they're spilled. This prevents code from
diff --git a/llvm/lib/Target/Hexagon/HexagonCFGOptimizer.cpp b/llvm/lib/Target/Hexagon/HexagonCFGOptimizer.cpp
index 96bb6175080..efafdd00728 100644
--- a/llvm/lib/Target/Hexagon/HexagonCFGOptimizer.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonCFGOptimizer.cpp
@@ -186,13 +186,11 @@ bool HexagonCFGOptimizer::runOnMachineFunction(MachineFunction &Fn) {
if (case1 || case2) {
InvertAndChangeJumpTarget(MI, UncondTarget);
- MBB->removeSuccessor(JumpAroundTarget);
- MBB->addSuccessor(UncondTarget);
+ MBB->replaceSuccessor(JumpAroundTarget, UncondTarget);
// Remove the unconditional branch in LayoutSucc.
LayoutSucc->erase(LayoutSucc->begin());
- LayoutSucc->removeSuccessor(UncondTarget);
- LayoutSucc->addSuccessor(JumpAroundTarget);
+ LayoutSucc->replaceSuccessor(UncondTarget, JumpAroundTarget);
// This code performs the conversion for case 2, which moves
// the block to the fall-thru case (BB3 in the code above).
diff --git a/llvm/lib/Target/Mips/MipsLongBranch.cpp b/llvm/lib/Target/Mips/MipsLongBranch.cpp
index d09843ed0e5..e75858a181e 100644
--- a/llvm/lib/Target/Mips/MipsLongBranch.cpp
+++ b/llvm/lib/Target/Mips/MipsLongBranch.cpp
@@ -262,8 +262,7 @@ void MipsLongBranch::expandToLongBranch(MBBInfo &I) {
static_cast<const MipsInstrInfo *>(Subtarget.getInstrInfo());
MF->insert(FallThroughMBB, LongBrMBB);
- MBB->removeSuccessor(TgtMBB);
- MBB->addSuccessor(LongBrMBB);
+ MBB->replaceSuccessor(TgtMBB, LongBrMBB);
if (IsPIC) {
MachineBasicBlock *BalTgtMBB = MF->CreateMachineBasicBlock(BB);
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