[llvm] r256263 - [BPI] Replace weights by probabilities in BPI.
Cong Hou via llvm-commits
llvm-commits at lists.llvm.org
Tue Dec 22 15:49:47 PST 2015
The fix is submitted as r256303. Thanks again for reporting the issue!
thanks,
Cong
On Tue, Dec 22, 2015 at 3:38 PM, Cong Hou <congh at google.com> wrote:
> Thanks for finding out the buggy place so fast! I will check the value of MaxBBSuccFreq
> and assign proper probabilities if it is zero.
>
>
> thanks,
> Cong
>
> On Tue, Dec 22, 2015 at 3:29 PM, Eric Christopher <echristo at gmail.com>
> wrote:
>
>> (In particular I'm running into it here:
>>
>> uint64_t MaxBBSuccFreq =
>> *std::max_element(BBSuccFreq.begin(), BBSuccFreq.end());
>> SmallVector<BranchProbability, 4> BBSuccProbs;
>> for (uint64_t Freq : BBSuccFreq)
>> BBSuccProbs.push_back(
>> BranchProbability::getBranchProbability(Freq, MaxBBSuccFreq));
>>
>> Where MaxBBSuccFreq is 0.)
>>
>> -eric
>>
>> On Tue, Dec 22, 2015 at 3:28 PM Eric Christopher <echristo at gmail.com>
>> wrote:
>>
>>> Thanks for the quick response!
>>>
>>> -eric
>>>
>>> On Tue, Dec 22, 2015 at 3:27 PM Cong Hou <congh at google.com> wrote:
>>>
>>>> Thanks! After reviewing my patch, I think I have found the places where
>>>> divide-by-zero may happen. I am working on the fix now. I will test it on
>>>> your testcase.
>>>>
>>>>
>>>> thanks,
>>>> Cong
>>>>
>>>> On Tue, Dec 22, 2015 at 3:23 PM, Eric Christopher <echristo at gmail.com>
>>>> wrote:
>>>>
>>>>> Working on a public testcase :)
>>>>>
>>>>> I've sent you some other links though.
>>>>>
>>>>> -eric
>>>>>
>>>>> On Tue, Dec 22, 2015 at 3:21 PM Cong Hou <congh at google.com> wrote:
>>>>>
>>>>>> Thanks for letting me know this. Could you please send me some links
>>>>>> showing such errors?
>>>>>>
>>>>>>
>>>>>>
>>>>>> thanks,
>>>>>> Cong
>>>>>>
>>>>>> On Tue, Dec 22, 2015 at 3:05 PM, Eric Christopher <echristo at gmail.com
>>>>>> > wrote:
>>>>>>
>>>>>>> Hi Cong,
>>>>>>>
>>>>>>> Just to let you know I'm seeing some (likely) divide by zeros here.
>>>>>>> I'm looking into it and will either fix, or revert and get a testcase for
>>>>>>> you.
>>>>>>>
>>>>>>> -eric
>>>>>>>
>>>>>>> On Tue, Dec 22, 2015 at 10:59 AM Cong Hou via llvm-commits <
>>>>>>> llvm-commits at lists.llvm.org> wrote:
>>>>>>>
>>>>>>>> Author: conghou
>>>>>>>> Date: Tue Dec 22 12:56:14 2015
>>>>>>>> New Revision: 256263
>>>>>>>>
>>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=256263&view=rev
>>>>>>>> Log:
>>>>>>>> [BPI] Replace weights by probabilities in BPI.
>>>>>>>>
>>>>>>>> This patch removes all weight-related interfaces from BPI and
>>>>>>>> replace
>>>>>>>> them by probability versions. With this patch, we won't use edge
>>>>>>>> weight
>>>>>>>> anymore in either IR or MC passes. Edge probabilitiy is a better
>>>>>>>> representation in terms of CFG update and validation.
>>>>>>>>
>>>>>>>>
>>>>>>>> Differential revision: http://reviews.llvm.org/D15519
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Modified:
>>>>>>>> llvm/trunk/include/llvm/Analysis/BranchProbabilityInfo.h
>>>>>>>> llvm/trunk/include/llvm/Support/BranchProbability.h
>>>>>>>> llvm/trunk/lib/Analysis/BranchProbabilityInfo.cpp
>>>>>>>> llvm/trunk/lib/CodeGen/StackProtector.cpp
>>>>>>>> llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
>>>>>>>> llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
>>>>>>>> llvm/trunk/test/Analysis/BranchProbabilityInfo/noreturn.ll
>>>>>>>> llvm/trunk/test/Transforms/JumpThreading/update-edge-weight.ll
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/include/llvm/Analysis/BranchProbabilityInfo.h
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/BranchProbabilityInfo.h?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/include/llvm/Analysis/BranchProbabilityInfo.h
>>>>>>>> (original)
>>>>>>>> +++ llvm/trunk/include/llvm/Analysis/BranchProbabilityInfo.h Tue
>>>>>>>> Dec 22 12:56:14 2015
>>>>>>>> @@ -84,36 +84,14 @@ public:
>>>>>>>> raw_ostream &printEdgeProbability(raw_ostream &OS, const
>>>>>>>> BasicBlock *Src,
>>>>>>>> const BasicBlock *Dst) const;
>>>>>>>>
>>>>>>>> - /// \brief Get the raw edge weight calculated for the edge.
>>>>>>>> + /// \brief Set the raw edge probability for the given edge.
>>>>>>>> ///
>>>>>>>> - /// This returns the raw edge weight. It is guaranteed to fall
>>>>>>>> between 1 and
>>>>>>>> - /// UINT32_MAX. Note that the raw edge weight is not meaningful
>>>>>>>> in isolation.
>>>>>>>> - /// This interface should be very carefully, and primarily by
>>>>>>>> routines that
>>>>>>>> - /// are updating the analysis by later calling setEdgeWeight.
>>>>>>>> - uint32_t getEdgeWeight(const BasicBlock *Src,
>>>>>>>> - unsigned IndexInSuccessors) const;
>>>>>>>> -
>>>>>>>> - /// \brief Get the raw edge weight calculated for the block pair.
>>>>>>>> - ///
>>>>>>>> - /// This returns the sum of all raw edge weights from Src to Dst.
>>>>>>>> - /// It is guaranteed to fall between 1 and UINT32_MAX.
>>>>>>>> - uint32_t getEdgeWeight(const BasicBlock *Src, const BasicBlock
>>>>>>>> *Dst) const;
>>>>>>>> -
>>>>>>>> - uint32_t getEdgeWeight(const BasicBlock *Src,
>>>>>>>> - succ_const_iterator Dst) const;
>>>>>>>> -
>>>>>>>> - /// \brief Set the raw edge weight for a given edge.
>>>>>>>> - ///
>>>>>>>> - /// This allows a pass to explicitly set the edge weight for an
>>>>>>>> edge. It can
>>>>>>>> - /// be used when updating the CFG to update and preserve the
>>>>>>>> branch
>>>>>>>> + /// This allows a pass to explicitly set the edge probability
>>>>>>>> for an edge. It
>>>>>>>> + /// can be used when updating the CFG to update and preserve the
>>>>>>>> branch
>>>>>>>> /// probability information. Read the implementation of how
>>>>>>>> these edge
>>>>>>>> - /// weights are calculated carefully before using!
>>>>>>>> - void setEdgeWeight(const BasicBlock *Src, unsigned
>>>>>>>> IndexInSuccessors,
>>>>>>>> - uint32_t Weight);
>>>>>>>> -
>>>>>>>> - static uint32_t getBranchWeightStackProtector(bool IsLikely) {
>>>>>>>> - return IsLikely ? (1u << 20) - 1 : 1;
>>>>>>>> - }
>>>>>>>> + /// probabilities are calculated carefully before using!
>>>>>>>> + void setEdgeProbability(const BasicBlock *Src, unsigned
>>>>>>>> IndexInSuccessors,
>>>>>>>> + BranchProbability Prob);
>>>>>>>>
>>>>>>>> static BranchProbability getBranchProbStackProtector(bool
>>>>>>>> IsLikely) {
>>>>>>>> static const BranchProbability LikelyProb((1u << 20) - 1, 1u
>>>>>>>> << 20);
>>>>>>>> @@ -135,7 +113,7 @@ private:
>>>>>>>> // weight to just "inherit" the non-zero weight of an adjacent
>>>>>>>> successor.
>>>>>>>> static const uint32_t DEFAULT_WEIGHT = 16;
>>>>>>>>
>>>>>>>> - DenseMap<Edge, uint32_t> Weights;
>>>>>>>> + DenseMap<Edge, BranchProbability> Probs;
>>>>>>>>
>>>>>>>> /// \brief Track the last function we run over for printing.
>>>>>>>> Function *LastF;
>>>>>>>> @@ -146,9 +124,6 @@ private:
>>>>>>>> /// \brief Track the set of blocks that always lead to a cold
>>>>>>>> call.
>>>>>>>> SmallPtrSet<BasicBlock *, 16> PostDominatedByColdCall;
>>>>>>>>
>>>>>>>> - /// \brief Get sum of the block successors' weights.
>>>>>>>> - uint32_t getSumForBlock(const BasicBlock *BB) const;
>>>>>>>> -
>>>>>>>> bool calcUnreachableHeuristics(BasicBlock *BB);
>>>>>>>> bool calcMetadataWeights(BasicBlock *BB);
>>>>>>>> bool calcColdCallHeuristics(BasicBlock *BB);
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/include/llvm/Support/BranchProbability.h
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/BranchProbability.h?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/include/llvm/Support/BranchProbability.h (original)
>>>>>>>> +++ llvm/trunk/include/llvm/Support/BranchProbability.h Tue Dec 22
>>>>>>>> 12:56:14 2015
>>>>>>>> @@ -63,11 +63,6 @@ public:
>>>>>>>> static void normalizeProbabilities(ProbabilityIter Begin,
>>>>>>>> ProbabilityIter End);
>>>>>>>>
>>>>>>>> - // Normalize a list of weights by scaling them down so that the
>>>>>>>> sum of them
>>>>>>>> - // doesn't exceed UINT32_MAX.
>>>>>>>> - template <class WeightListIter>
>>>>>>>> - static void normalizeEdgeWeights(WeightListIter Begin,
>>>>>>>> WeightListIter End);
>>>>>>>> -
>>>>>>>> uint32_t getNumerator() const { return N; }
>>>>>>>> static uint32_t getDenominator() { return D; }
>>>>>>>>
>>>>>>>> @@ -219,49 +214,6 @@ void BranchProbability::normalizeProbabi
>>>>>>>> I->N = (I->N * uint64_t(D) + Sum / 2) / Sum;
>>>>>>>> }
>>>>>>>>
>>>>>>>> -template <class WeightListIter>
>>>>>>>> -void BranchProbability::normalizeEdgeWeights(WeightListIter Begin,
>>>>>>>> - WeightListIter End) {
>>>>>>>> - // First we compute the sum with 64-bits of precision.
>>>>>>>> - uint64_t Sum = std::accumulate(Begin, End, uint64_t(0));
>>>>>>>> -
>>>>>>>> - if (Sum > UINT32_MAX) {
>>>>>>>> - // Compute the scale necessary to cause the weights to fit,
>>>>>>>> and re-sum with
>>>>>>>> - // that scale applied.
>>>>>>>> - assert(Sum / UINT32_MAX < UINT32_MAX &&
>>>>>>>> - "The sum of weights exceeds UINT32_MAX^2!");
>>>>>>>> - uint32_t Scale = Sum / UINT32_MAX + 1;
>>>>>>>> - for (auto I = Begin; I != End; ++I)
>>>>>>>> - *I /= Scale;
>>>>>>>> - Sum = std::accumulate(Begin, End, uint64_t(0));
>>>>>>>> - }
>>>>>>>> -
>>>>>>>> - // Eliminate zero weights.
>>>>>>>> - auto ZeroWeightNum = std::count(Begin, End, 0u);
>>>>>>>> - if (ZeroWeightNum > 0) {
>>>>>>>> - // If all weights are zeros, replace them by 1.
>>>>>>>> - if (Sum == 0)
>>>>>>>> - std::fill(Begin, End, 1u);
>>>>>>>> - else {
>>>>>>>> - // We are converting zeros into ones, and here we need to
>>>>>>>> make sure that
>>>>>>>> - // after this the sum won't exceed UINT32_MAX.
>>>>>>>> - if (Sum + ZeroWeightNum > UINT32_MAX) {
>>>>>>>> - for (auto I = Begin; I != End; ++I)
>>>>>>>> - *I /= 2;
>>>>>>>> - ZeroWeightNum = std::count(Begin, End, 0u);
>>>>>>>> - Sum = std::accumulate(Begin, End, uint64_t(0));
>>>>>>>> - }
>>>>>>>> - // Scale up non-zero weights and turn zero weights into ones.
>>>>>>>> - uint64_t ScalingFactor = (UINT32_MAX - ZeroWeightNum) / Sum;
>>>>>>>> - assert(ScalingFactor >= 1);
>>>>>>>> - if (ScalingFactor > 1)
>>>>>>>> - for (auto I = Begin; I != End; ++I)
>>>>>>>> - *I *= ScalingFactor;
>>>>>>>> - std::replace(Begin, End, 0u, 1u);
>>>>>>>> - }
>>>>>>>> - }
>>>>>>>> -}
>>>>>>>> -
>>>>>>>> }
>>>>>>>>
>>>>>>>> #endif
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/lib/Analysis/BranchProbabilityInfo.cpp
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BranchProbabilityInfo.cpp?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/lib/Analysis/BranchProbabilityInfo.cpp (original)
>>>>>>>> +++ llvm/trunk/lib/Analysis/BranchProbabilityInfo.cpp Tue Dec 22
>>>>>>>> 12:56:14 2015
>>>>>>>> @@ -108,13 +108,6 @@ static const uint32_t IH_TAKEN_WEIGHT =
>>>>>>>> /// instruction. This is essentially never taken.
>>>>>>>> static const uint32_t IH_NONTAKEN_WEIGHT = 1;
>>>>>>>>
>>>>>>>> -// Standard weight value. Used when none of the heuristics set
>>>>>>>> weight for
>>>>>>>> -// the edge.
>>>>>>>> -static const uint32_t NORMAL_WEIGHT = 16;
>>>>>>>> -
>>>>>>>> -// Minimum weight of an edge. Please note, that weight is NEVER 0.
>>>>>>>> -static const uint32_t MIN_WEIGHT = 1;
>>>>>>>> -
>>>>>>>> /// \brief Calculate edge weights for successors lead to
>>>>>>>> unreachable.
>>>>>>>> ///
>>>>>>>> /// Predict that a successor which leads necessarily to an
>>>>>>>> @@ -157,22 +150,24 @@ bool BranchProbabilityInfo::calcUnreacha
>>>>>>>> return false;
>>>>>>>> }
>>>>>>>>
>>>>>>>> - uint32_t UnreachableWeight =
>>>>>>>> - std::max(UR_TAKEN_WEIGHT / (unsigned)UnreachableEdges.size(),
>>>>>>>> MIN_WEIGHT);
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator I =
>>>>>>>> UnreachableEdges.begin(),
>>>>>>>> - E =
>>>>>>>> UnreachableEdges.end();
>>>>>>>> - I != E; ++I)
>>>>>>>> - setEdgeWeight(BB, *I, UnreachableWeight);
>>>>>>>> -
>>>>>>>> - if (ReachableEdges.empty())
>>>>>>>> + if (ReachableEdges.empty()) {
>>>>>>>> + BranchProbability Prob(1, UnreachableEdges.size());
>>>>>>>> + for (unsigned SuccIdx : UnreachableEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, Prob);
>>>>>>>> return true;
>>>>>>>> - uint32_t ReachableWeight =
>>>>>>>> - std::max(UR_NONTAKEN_WEIGHT / (unsigned)ReachableEdges.size(),
>>>>>>>> - NORMAL_WEIGHT);
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator I =
>>>>>>>> ReachableEdges.begin(),
>>>>>>>> - E =
>>>>>>>> ReachableEdges.end();
>>>>>>>> - I != E; ++I)
>>>>>>>> - setEdgeWeight(BB, *I, ReachableWeight);
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + BranchProbability UnreachableProb(UR_TAKEN_WEIGHT,
>>>>>>>> + (UR_TAKEN_WEIGHT +
>>>>>>>> UR_NONTAKEN_WEIGHT) *
>>>>>>>> + UnreachableEdges.size());
>>>>>>>> + BranchProbability ReachableProb(UR_NONTAKEN_WEIGHT,
>>>>>>>> + (UR_TAKEN_WEIGHT +
>>>>>>>> UR_NONTAKEN_WEIGHT) *
>>>>>>>> + ReachableEdges.size());
>>>>>>>> +
>>>>>>>> + for (unsigned SuccIdx : UnreachableEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, UnreachableProb);
>>>>>>>> + for (unsigned SuccIdx : ReachableEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, ReachableProb);
>>>>>>>>
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>> @@ -223,10 +218,12 @@ bool BranchProbabilityInfo::calcMetadata
>>>>>>>>
>>>>>>>> WeightSum = 0;
>>>>>>>> for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) {
>>>>>>>> - uint32_t W = Weights[i] / ScalingFactor;
>>>>>>>> - WeightSum += W;
>>>>>>>> - setEdgeWeight(BB, i, W);
>>>>>>>> + Weights[i] /= ScalingFactor;
>>>>>>>> + WeightSum += Weights[i];
>>>>>>>> }
>>>>>>>> + for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
>>>>>>>> + setEdgeProbability(BB, i, {Weights[i],
>>>>>>>> static_cast<uint32_t>(WeightSum)});
>>>>>>>> +
>>>>>>>> assert(WeightSum <= UINT32_MAX &&
>>>>>>>> "Expected weights to scale down to 32 bits");
>>>>>>>>
>>>>>>>> @@ -275,21 +272,24 @@ bool BranchProbabilityInfo::calcColdCall
>>>>>>>> if (TI->getNumSuccessors() == 1 || ColdEdges.empty())
>>>>>>>> return false;
>>>>>>>>
>>>>>>>> - uint32_t ColdWeight =
>>>>>>>> - std::max(CC_TAKEN_WEIGHT / (unsigned) ColdEdges.size(),
>>>>>>>> MIN_WEIGHT);
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator I = ColdEdges.begin(),
>>>>>>>> - E = ColdEdges.end();
>>>>>>>> - I != E; ++I)
>>>>>>>> - setEdgeWeight(BB, *I, ColdWeight);
>>>>>>>> -
>>>>>>>> - if (NormalEdges.empty())
>>>>>>>> + if (NormalEdges.empty()) {
>>>>>>>> + BranchProbability Prob(1, ColdEdges.size());
>>>>>>>> + for (unsigned SuccIdx : ColdEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, Prob);
>>>>>>>> return true;
>>>>>>>> - uint32_t NormalWeight = std::max(
>>>>>>>> - CC_NONTAKEN_WEIGHT / (unsigned) NormalEdges.size(),
>>>>>>>> NORMAL_WEIGHT);
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator I = NormalEdges.begin(),
>>>>>>>> - E = NormalEdges.end();
>>>>>>>> - I != E; ++I)
>>>>>>>> - setEdgeWeight(BB, *I, NormalWeight);
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + BranchProbability ColdProb(CC_TAKEN_WEIGHT,
>>>>>>>> + (CC_TAKEN_WEIGHT +
>>>>>>>> CC_NONTAKEN_WEIGHT) *
>>>>>>>> + ColdEdges.size());
>>>>>>>> + BranchProbability NormalProb(CC_NONTAKEN_WEIGHT,
>>>>>>>> + (CC_TAKEN_WEIGHT +
>>>>>>>> CC_NONTAKEN_WEIGHT) *
>>>>>>>> + NormalEdges.size());
>>>>>>>> +
>>>>>>>> + for (unsigned SuccIdx : ColdEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, ColdProb);
>>>>>>>> + for (unsigned SuccIdx : NormalEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, NormalProb);
>>>>>>>>
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>> @@ -322,8 +322,10 @@ bool BranchProbabilityInfo::calcPointerH
>>>>>>>> if (!isProb)
>>>>>>>> std::swap(TakenIdx, NonTakenIdx);
>>>>>>>>
>>>>>>>> - setEdgeWeight(BB, TakenIdx, PH_TAKEN_WEIGHT);
>>>>>>>> - setEdgeWeight(BB, NonTakenIdx, PH_NONTAKEN_WEIGHT);
>>>>>>>> + BranchProbability TakenProb(PH_TAKEN_WEIGHT,
>>>>>>>> + PH_TAKEN_WEIGHT +
>>>>>>>> PH_NONTAKEN_WEIGHT);
>>>>>>>> + setEdgeProbability(BB, TakenIdx, TakenProb);
>>>>>>>> + setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>>
>>>>>>>> @@ -351,37 +353,35 @@ bool BranchProbabilityInfo::calcLoopBran
>>>>>>>> if (BackEdges.empty() && ExitingEdges.empty())
>>>>>>>> return false;
>>>>>>>>
>>>>>>>> + // Collect the sum of probabilities of
>>>>>>>> back-edges/in-edges/exiting-edges, and
>>>>>>>> + // normalize them so that they sum up to one.
>>>>>>>> + SmallVector<BranchProbability, 4> Probs(3,
>>>>>>>> BranchProbability::getZero());
>>>>>>>> + unsigned Denom = (BackEdges.empty() ? 0 : LBH_TAKEN_WEIGHT) +
>>>>>>>> + (InEdges.empty() ? 0 : LBH_TAKEN_WEIGHT) +
>>>>>>>> + (ExitingEdges.empty() ? 0 :
>>>>>>>> LBH_NONTAKEN_WEIGHT);
>>>>>>>> + if (!BackEdges.empty())
>>>>>>>> + Probs[0] = BranchProbability(LBH_TAKEN_WEIGHT, Denom);
>>>>>>>> + if (!InEdges.empty())
>>>>>>>> + Probs[1] = BranchProbability(LBH_TAKEN_WEIGHT, Denom);
>>>>>>>> + if (!ExitingEdges.empty())
>>>>>>>> + Probs[2] = BranchProbability(LBH_NONTAKEN_WEIGHT, Denom);
>>>>>>>> +
>>>>>>>> if (uint32_t numBackEdges = BackEdges.size()) {
>>>>>>>> - uint32_t backWeight = LBH_TAKEN_WEIGHT / numBackEdges;
>>>>>>>> - if (backWeight < NORMAL_WEIGHT)
>>>>>>>> - backWeight = NORMAL_WEIGHT;
>>>>>>>> -
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator EI =
>>>>>>>> BackEdges.begin(),
>>>>>>>> - EE = BackEdges.end(); EI != EE; ++EI) {
>>>>>>>> - setEdgeWeight(BB, *EI, backWeight);
>>>>>>>> - }
>>>>>>>> + auto Prob = Probs[0] / numBackEdges;
>>>>>>>> + for (unsigned SuccIdx : BackEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, Prob);
>>>>>>>> }
>>>>>>>>
>>>>>>>> if (uint32_t numInEdges = InEdges.size()) {
>>>>>>>> - uint32_t inWeight = LBH_TAKEN_WEIGHT / numInEdges;
>>>>>>>> - if (inWeight < NORMAL_WEIGHT)
>>>>>>>> - inWeight = NORMAL_WEIGHT;
>>>>>>>> -
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator EI = InEdges.begin(),
>>>>>>>> - EE = InEdges.end(); EI != EE; ++EI) {
>>>>>>>> - setEdgeWeight(BB, *EI, inWeight);
>>>>>>>> - }
>>>>>>>> + auto Prob = Probs[1] / numInEdges;
>>>>>>>> + for (unsigned SuccIdx : InEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, Prob);
>>>>>>>> }
>>>>>>>>
>>>>>>>> if (uint32_t numExitingEdges = ExitingEdges.size()) {
>>>>>>>> - uint32_t exitWeight = LBH_NONTAKEN_WEIGHT / numExitingEdges;
>>>>>>>> - if (exitWeight < MIN_WEIGHT)
>>>>>>>> - exitWeight = MIN_WEIGHT;
>>>>>>>> -
>>>>>>>> - for (SmallVectorImpl<unsigned>::iterator EI =
>>>>>>>> ExitingEdges.begin(),
>>>>>>>> - EE = ExitingEdges.end(); EI != EE; ++EI) {
>>>>>>>> - setEdgeWeight(BB, *EI, exitWeight);
>>>>>>>> - }
>>>>>>>> + auto Prob = Probs[2] / numExitingEdges;
>>>>>>>> + for (unsigned SuccIdx : ExitingEdges)
>>>>>>>> + setEdgeProbability(BB, SuccIdx, Prob);
>>>>>>>> }
>>>>>>>>
>>>>>>>> return true;
>>>>>>>> @@ -463,9 +463,10 @@ bool BranchProbabilityInfo::calcZeroHeur
>>>>>>>> if (!isProb)
>>>>>>>> std::swap(TakenIdx, NonTakenIdx);
>>>>>>>>
>>>>>>>> - setEdgeWeight(BB, TakenIdx, ZH_TAKEN_WEIGHT);
>>>>>>>> - setEdgeWeight(BB, NonTakenIdx, ZH_NONTAKEN_WEIGHT);
>>>>>>>> -
>>>>>>>> + BranchProbability TakenProb(ZH_TAKEN_WEIGHT,
>>>>>>>> + ZH_TAKEN_WEIGHT +
>>>>>>>> ZH_NONTAKEN_WEIGHT);
>>>>>>>> + setEdgeProbability(BB, TakenIdx, TakenProb);
>>>>>>>> + setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>>
>>>>>>>> @@ -499,9 +500,10 @@ bool BranchProbabilityInfo::calcFloating
>>>>>>>> if (!isProb)
>>>>>>>> std::swap(TakenIdx, NonTakenIdx);
>>>>>>>>
>>>>>>>> - setEdgeWeight(BB, TakenIdx, FPH_TAKEN_WEIGHT);
>>>>>>>> - setEdgeWeight(BB, NonTakenIdx, FPH_NONTAKEN_WEIGHT);
>>>>>>>> -
>>>>>>>> + BranchProbability TakenProb(FPH_TAKEN_WEIGHT,
>>>>>>>> + FPH_TAKEN_WEIGHT +
>>>>>>>> FPH_NONTAKEN_WEIGHT);
>>>>>>>> + setEdgeProbability(BB, TakenIdx, TakenProb);
>>>>>>>> + setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>>
>>>>>>>> @@ -510,13 +512,15 @@ bool BranchProbabilityInfo::calcInvokeHe
>>>>>>>> if (!II)
>>>>>>>> return false;
>>>>>>>>
>>>>>>>> - setEdgeWeight(BB, 0/*Index for Normal*/, IH_TAKEN_WEIGHT);
>>>>>>>> - setEdgeWeight(BB, 1/*Index for Unwind*/, IH_NONTAKEN_WEIGHT);
>>>>>>>> + BranchProbability TakenProb(IH_TAKEN_WEIGHT,
>>>>>>>> + IH_TAKEN_WEIGHT +
>>>>>>>> IH_NONTAKEN_WEIGHT);
>>>>>>>> + setEdgeProbability(BB, 0 /*Index for Normal*/, TakenProb);
>>>>>>>> + setEdgeProbability(BB, 1 /*Index for Unwind*/,
>>>>>>>> TakenProb.getCompl());
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>>
>>>>>>>> void BranchProbabilityInfo::releaseMemory() {
>>>>>>>> - Weights.clear();
>>>>>>>> + Probs.clear();
>>>>>>>> }
>>>>>>>>
>>>>>>>> void BranchProbabilityInfo::print(raw_ostream &OS) const {
>>>>>>>> @@ -532,20 +536,6 @@ void BranchProbabilityInfo::print(raw_os
>>>>>>>> }
>>>>>>>> }
>>>>>>>>
>>>>>>>> -uint32_t BranchProbabilityInfo::getSumForBlock(const BasicBlock
>>>>>>>> *BB) const {
>>>>>>>> - uint32_t Sum = 0;
>>>>>>>> -
>>>>>>>> - for (succ_const_iterator I = succ_begin(BB), E = succ_end(BB); I
>>>>>>>> != E; ++I) {
>>>>>>>> - uint32_t Weight = getEdgeWeight(BB, I.getSuccessorIndex());
>>>>>>>> - uint32_t PrevSum = Sum;
>>>>>>>> -
>>>>>>>> - Sum += Weight;
>>>>>>>> - assert(Sum >= PrevSum); (void) PrevSum;
>>>>>>>> - }
>>>>>>>> -
>>>>>>>> - return Sum;
>>>>>>>> -}
>>>>>>>> -
>>>>>>>> bool BranchProbabilityInfo::
>>>>>>>> isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const {
>>>>>>>> // Hot probability is at least 4/5 = 80%
>>>>>>>> @@ -554,113 +544,74 @@ isEdgeHot(const BasicBlock *Src, const B
>>>>>>>> }
>>>>>>>>
>>>>>>>> BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB)
>>>>>>>> const {
>>>>>>>> - uint32_t Sum = 0;
>>>>>>>> - uint32_t MaxWeight = 0;
>>>>>>>> + auto MaxProb = BranchProbability::getZero();
>>>>>>>> BasicBlock *MaxSucc = nullptr;
>>>>>>>>
>>>>>>>> for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E;
>>>>>>>> ++I) {
>>>>>>>> BasicBlock *Succ = *I;
>>>>>>>> - uint32_t Weight = getEdgeWeight(BB, Succ);
>>>>>>>> - uint32_t PrevSum = Sum;
>>>>>>>> -
>>>>>>>> - Sum += Weight;
>>>>>>>> - assert(Sum > PrevSum); (void) PrevSum;
>>>>>>>> -
>>>>>>>> - if (Weight > MaxWeight) {
>>>>>>>> - MaxWeight = Weight;
>>>>>>>> + auto Prob = getEdgeProbability(BB, Succ);
>>>>>>>> + if (Prob > MaxProb) {
>>>>>>>> + MaxProb = Prob;
>>>>>>>> MaxSucc = Succ;
>>>>>>>> }
>>>>>>>> }
>>>>>>>>
>>>>>>>> // Hot probability is at least 4/5 = 80%
>>>>>>>> - if (BranchProbability(MaxWeight, Sum) > BranchProbability(4, 5))
>>>>>>>> + if (MaxProb > BranchProbability(4, 5))
>>>>>>>> return MaxSucc;
>>>>>>>>
>>>>>>>> return nullptr;
>>>>>>>> }
>>>>>>>>
>>>>>>>> -/// Get the raw edge weight for the edge. If can't find it, return
>>>>>>>> -/// DEFAULT_WEIGHT value. Here an edge is specified using
>>>>>>>> PredBlock and an index
>>>>>>>> -/// to the successors.
>>>>>>>> -uint32_t BranchProbabilityInfo::
>>>>>>>> -getEdgeWeight(const BasicBlock *Src, unsigned IndexInSuccessors)
>>>>>>>> const {
>>>>>>>> - DenseMap<Edge, uint32_t>::const_iterator I =
>>>>>>>> - Weights.find(std::make_pair(Src, IndexInSuccessors));
>>>>>>>> +/// Get the raw edge probability for the edge. If can't find it,
>>>>>>>> return a
>>>>>>>> +/// default probability 1/N where N is the number of successors.
>>>>>>>> Here an edge is
>>>>>>>> +/// specified using PredBlock and an
>>>>>>>> +/// index to the successors.
>>>>>>>> +BranchProbability
>>>>>>>> +BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
>>>>>>>> + unsigned
>>>>>>>> IndexInSuccessors) const {
>>>>>>>> + auto I = Probs.find(std::make_pair(Src, IndexInSuccessors));
>>>>>>>>
>>>>>>>> - if (I != Weights.end())
>>>>>>>> + if (I != Probs.end())
>>>>>>>> return I->second;
>>>>>>>>
>>>>>>>> - return DEFAULT_WEIGHT;
>>>>>>>> + return {1,
>>>>>>>> + static_cast<uint32_t>(std::distance(succ_begin(Src),
>>>>>>>> succ_end(Src)))};
>>>>>>>> }
>>>>>>>>
>>>>>>>> -uint32_t BranchProbabilityInfo::getEdgeWeight(const BasicBlock
>>>>>>>> *Src,
>>>>>>>> - succ_const_iterator
>>>>>>>> Dst) const {
>>>>>>>> - return getEdgeWeight(Src, Dst.getSuccessorIndex());
>>>>>>>> +BranchProbability
>>>>>>>> +BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
>>>>>>>> + succ_const_iterator Dst)
>>>>>>>> const {
>>>>>>>> + return getEdgeProbability(Src, Dst.getSuccessorIndex());
>>>>>>>> }
>>>>>>>>
>>>>>>>> -/// Get the raw edge weight calculated for the block pair. This
>>>>>>>> returns the sum
>>>>>>>> -/// of all raw edge weights from Src to Dst.
>>>>>>>> -uint32_t BranchProbabilityInfo::
>>>>>>>> -getEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst) const {
>>>>>>>> - uint32_t Weight = 0;
>>>>>>>> - bool FoundWeight = false;
>>>>>>>> - DenseMap<Edge, uint32_t>::const_iterator MapI;
>>>>>>>> +/// Get the raw edge probability calculated for the block pair.
>>>>>>>> This returns the
>>>>>>>> +/// sum of all raw edge probabilities from Src to Dst.
>>>>>>>> +BranchProbability
>>>>>>>> +BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
>>>>>>>> + const BasicBlock *Dst)
>>>>>>>> const {
>>>>>>>> + auto Prob = BranchProbability::getZero();
>>>>>>>> + bool FoundProb = false;
>>>>>>>> for (succ_const_iterator I = succ_begin(Src), E = succ_end(Src);
>>>>>>>> I != E; ++I)
>>>>>>>> if (*I == Dst) {
>>>>>>>> - MapI = Weights.find(std::make_pair(Src,
>>>>>>>> I.getSuccessorIndex()));
>>>>>>>> - if (MapI != Weights.end()) {
>>>>>>>> - FoundWeight = true;
>>>>>>>> - Weight += MapI->second;
>>>>>>>> + auto MapI = Probs.find(std::make_pair(Src,
>>>>>>>> I.getSuccessorIndex()));
>>>>>>>> + if (MapI != Probs.end()) {
>>>>>>>> + FoundProb = true;
>>>>>>>> + Prob += MapI->second;
>>>>>>>> }
>>>>>>>> }
>>>>>>>> - return (!FoundWeight) ? DEFAULT_WEIGHT : Weight;
>>>>>>>> -}
>>>>>>>> -
>>>>>>>> -/// Set the edge weight for a given edge specified by PredBlock
>>>>>>>> and an index
>>>>>>>> -/// to the successors.
>>>>>>>> -void BranchProbabilityInfo::
>>>>>>>> -setEdgeWeight(const BasicBlock *Src, unsigned IndexInSuccessors,
>>>>>>>> - uint32_t Weight) {
>>>>>>>> - Weights[std::make_pair(Src, IndexInSuccessors)] = Weight;
>>>>>>>> - DEBUG(dbgs() << "set edge " << Src->getName() << " -> "
>>>>>>>> - << IndexInSuccessors << " successor weight to "
>>>>>>>> - << Weight << "\n");
>>>>>>>> + uint32_t succ_num = std::distance(succ_begin(Src),
>>>>>>>> succ_end(Src));
>>>>>>>> + return FoundProb ? Prob : BranchProbability(1, succ_num);
>>>>>>>> }
>>>>>>>>
>>>>>>>> -/// Get an edge's probability, relative to other out-edges from
>>>>>>>> Src.
>>>>>>>> -BranchProbability BranchProbabilityInfo::
>>>>>>>> -getEdgeProbability(const BasicBlock *Src, unsigned
>>>>>>>> IndexInSuccessors) const {
>>>>>>>> - uint32_t N = getEdgeWeight(Src, IndexInSuccessors);
>>>>>>>> - uint32_t D = getSumForBlock(Src);
>>>>>>>> -
>>>>>>>> - // It is possible that the edge weight on the only successor
>>>>>>>> edge of Src is
>>>>>>>> - // zero, in which case we return 100%.
>>>>>>>> - if (N == 0 && D == 0)
>>>>>>>> - return BranchProbability::getOne();
>>>>>>>> -
>>>>>>>> - return BranchProbability(N, D);
>>>>>>>> -}
>>>>>>>> -
>>>>>>>> -/// Get the probability of going from Src to Dst. It returns the
>>>>>>>> sum of all
>>>>>>>> -/// probabilities for edges from Src to Dst.
>>>>>>>> -BranchProbability BranchProbabilityInfo::
>>>>>>>> -getEdgeProbability(const BasicBlock *Src, const BasicBlock *Dst)
>>>>>>>> const {
>>>>>>>> -
>>>>>>>> - uint32_t N = getEdgeWeight(Src, Dst);
>>>>>>>> - uint32_t D = getSumForBlock(Src);
>>>>>>>> -
>>>>>>>> - // It is possible that the edge weight on the only successor
>>>>>>>> edge of Src is
>>>>>>>> - // zero, in which case we return 100%.
>>>>>>>> - if (N == 0 && D == 0)
>>>>>>>> - return BranchProbability::getOne();
>>>>>>>> -
>>>>>>>> - return BranchProbability(N, D);
>>>>>>>> -}
>>>>>>>> -
>>>>>>>> -BranchProbability
>>>>>>>> -BranchProbabilityInfo::getEdgeProbability(const BasicBlock *Src,
>>>>>>>> - succ_const_iterator Dst)
>>>>>>>> const {
>>>>>>>> - return getEdgeProbability(Src, Dst.getSuccessorIndex());
>>>>>>>> +/// Set the edge probability for a given edge specified by
>>>>>>>> PredBlock and an
>>>>>>>> +/// index to the successors.
>>>>>>>> +void BranchProbabilityInfo::setEdgeProbability(const BasicBlock
>>>>>>>> *Src,
>>>>>>>> + unsigned
>>>>>>>> IndexInSuccessors,
>>>>>>>> + BranchProbability
>>>>>>>> Prob) {
>>>>>>>> + Probs[std::make_pair(Src, IndexInSuccessors)] = Prob;
>>>>>>>> + DEBUG(dbgs() << "set edge " << Src->getName() << " -> " <<
>>>>>>>> IndexInSuccessors
>>>>>>>> + << " successor probability to " << Prob << "\n");
>>>>>>>> }
>>>>>>>>
>>>>>>>> raw_ostream &
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/lib/CodeGen/StackProtector.cpp
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StackProtector.cpp?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/lib/CodeGen/StackProtector.cpp (original)
>>>>>>>> +++ llvm/trunk/lib/CodeGen/StackProtector.cpp Tue Dec 22 12:56:14
>>>>>>>> 2015
>>>>>>>> @@ -453,12 +453,13 @@ bool StackProtector::InsertStackProtecto
>>>>>>>> LoadInst *LI1 = B.CreateLoad(StackGuardVar);
>>>>>>>> LoadInst *LI2 = B.CreateLoad(AI);
>>>>>>>> Value *Cmp = B.CreateICmpEQ(LI1, LI2);
>>>>>>>> - unsigned SuccessWeight =
>>>>>>>> -
>>>>>>>> BranchProbabilityInfo::getBranchWeightStackProtector(true);
>>>>>>>> - unsigned FailureWeight =
>>>>>>>> -
>>>>>>>> BranchProbabilityInfo::getBranchWeightStackProtector(false);
>>>>>>>> + auto SuccessProb =
>>>>>>>> + BranchProbabilityInfo::getBranchProbStackProtector(true);
>>>>>>>> + auto FailureProb =
>>>>>>>> +
>>>>>>>> BranchProbabilityInfo::getBranchProbStackProtector(false);
>>>>>>>> MDNode *Weights = MDBuilder(F->getContext())
>>>>>>>> - .createBranchWeights(SuccessWeight,
>>>>>>>> FailureWeight);
>>>>>>>> +
>>>>>>>> .createBranchWeights(SuccessProb.getNumerator(),
>>>>>>>> +
>>>>>>>> FailureProb.getNumerator());
>>>>>>>> B.CreateCondBr(Cmp, NewBB, FailBB, Weights);
>>>>>>>> }
>>>>>>>> }
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp (original)
>>>>>>>> +++ llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp Tue Dec 22
>>>>>>>> 12:56:14 2015
>>>>>>>> @@ -414,8 +414,8 @@ static unsigned getBranchHint(unsigned P
>>>>>>>> const BasicBlock *TBB = BBTerm->getSuccessor(0);
>>>>>>>> const BasicBlock *FBB = BBTerm->getSuccessor(1);
>>>>>>>>
>>>>>>>> - uint32_t TWeight = FuncInfo->BPI->getEdgeWeight(BB, TBB);
>>>>>>>> - uint32_t FWeight = FuncInfo->BPI->getEdgeWeight(BB, FBB);
>>>>>>>> + auto TProb = FuncInfo->BPI->getEdgeProbability(BB, TBB);
>>>>>>>> + auto FProb = FuncInfo->BPI->getEdgeProbability(BB, FBB);
>>>>>>>>
>>>>>>>> // We only want to handle cases which are easy to predict at
>>>>>>>> static time, e.g.
>>>>>>>> // C++ throw statement, that is very likely not taken, or
>>>>>>>> calling never
>>>>>>>> @@ -432,24 +432,22 @@ static unsigned getBranchHint(unsigned P
>>>>>>>> // 5. PH/ZH/FPH 20:12
>>>>>>>> const uint32_t Threshold = 10000;
>>>>>>>>
>>>>>>>> - // Minimal weight should be at least 1
>>>>>>>> - if (std::max(TWeight, FWeight) /
>>>>>>>> - std::max(1u, std::min(TWeight, FWeight)) < Threshold)
>>>>>>>> + if (std::max(TProb, FProb) / Threshold < std::min(TProb, FProb))
>>>>>>>> return PPC::BR_NO_HINT;
>>>>>>>>
>>>>>>>> DEBUG(dbgs() << "Use branch hint for '" <<
>>>>>>>> FuncInfo->Fn->getName() << "::"
>>>>>>>> << BB->getName() << "'\n"
>>>>>>>> - << " -> " << TBB->getName() << ": " << TWeight <<
>>>>>>>> "\n"
>>>>>>>> - << " -> " << FBB->getName() << ": " << FWeight <<
>>>>>>>> "\n");
>>>>>>>> + << " -> " << TBB->getName() << ": " << TProb << "\n"
>>>>>>>> + << " -> " << FBB->getName() << ": " << FProb <<
>>>>>>>> "\n");
>>>>>>>>
>>>>>>>> const BasicBlockSDNode *BBDN = cast<BasicBlockSDNode>(DestMBB);
>>>>>>>>
>>>>>>>> - // If Dest BasicBlock is False-BasicBlock (FBB), swap branch
>>>>>>>> weight,
>>>>>>>> - // because we want 'TWeight' stands for 'branch weight' to Dest
>>>>>>>> BasicBlock
>>>>>>>> + // If Dest BasicBlock is False-BasicBlock (FBB), swap branch
>>>>>>>> probabilities,
>>>>>>>> + // because we want 'TProb' stands for 'branch probability' to
>>>>>>>> Dest BasicBlock
>>>>>>>> if (BBDN->getBasicBlock()->getBasicBlock() != TBB)
>>>>>>>> - std::swap(TWeight, FWeight);
>>>>>>>> + std::swap(TProb, FProb);
>>>>>>>>
>>>>>>>> - return (TWeight > FWeight) ? PPC::BR_TAKEN_HINT :
>>>>>>>> PPC::BR_NONTAKEN_HINT;
>>>>>>>> + return (TProb > FProb) ? PPC::BR_TAKEN_HINT :
>>>>>>>> PPC::BR_NONTAKEN_HINT;
>>>>>>>> }
>>>>>>>>
>>>>>>>> // isOpcWithIntImmediate - This method tests to see if the node is
>>>>>>>> a specific
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp (original)
>>>>>>>> +++ llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp Tue Dec 22
>>>>>>>> 12:56:14 2015
>>>>>>>> @@ -1636,7 +1636,7 @@ void JumpThreading::UpdateBlockFreqAndEd
>>>>>>>> BFI->setBlockFreq(BB, BBNewFreq.getFrequency());
>>>>>>>>
>>>>>>>> // Collect updated outgoing edges' frequencies from BB and use
>>>>>>>> them to update
>>>>>>>> - // edge weights.
>>>>>>>> + // edge probabilities.
>>>>>>>> SmallVector<uint64_t, 4> BBSuccFreq;
>>>>>>>> for (auto I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
>>>>>>>> auto SuccFreq = (*I == SuccBB)
>>>>>>>> @@ -1645,18 +1645,26 @@ void JumpThreading::UpdateBlockFreqAndEd
>>>>>>>> BBSuccFreq.push_back(SuccFreq.getFrequency());
>>>>>>>> }
>>>>>>>>
>>>>>>>> - // Normalize edge weights in Weights64 so that the sum of them
>>>>>>>> can fit in
>>>>>>>> - BranchProbability::normalizeEdgeWeights(BBSuccFreq.begin(),
>>>>>>>> BBSuccFreq.end());
>>>>>>>> + uint64_t MaxBBSuccFreq =
>>>>>>>> + *std::max_element(BBSuccFreq.begin(), BBSuccFreq.end());
>>>>>>>> + SmallVector<BranchProbability, 4> BBSuccProbs;
>>>>>>>> + for (uint64_t Freq : BBSuccFreq)
>>>>>>>> + BBSuccProbs.push_back(
>>>>>>>> + BranchProbability::getBranchProbability(Freq,
>>>>>>>> MaxBBSuccFreq));
>>>>>>>>
>>>>>>>> - SmallVector<uint32_t, 4> Weights;
>>>>>>>> - for (auto Freq : BBSuccFreq)
>>>>>>>> - Weights.push_back(static_cast<uint32_t>(Freq));
>>>>>>>> -
>>>>>>>> - // Update edge weights in BPI.
>>>>>>>> - for (int I = 0, E = Weights.size(); I < E; I++)
>>>>>>>> - BPI->setEdgeWeight(BB, I, Weights[I]);
>>>>>>>> + // Normalize edge probabilities so that they sum up to one.
>>>>>>>> + BranchProbability::normalizeProbabilities(BBSuccProbs.begin(),
>>>>>>>> + BBSuccProbs.end());
>>>>>>>> +
>>>>>>>> + // Update edge probabilities in BPI.
>>>>>>>> + for (int I = 0, E = BBSuccProbs.size(); I < E; I++)
>>>>>>>> + BPI->setEdgeProbability(BB, I, BBSuccProbs[I]);
>>>>>>>> +
>>>>>>>> + if (BBSuccProbs.size() >= 2) {
>>>>>>>> + SmallVector<uint32_t, 4> Weights;
>>>>>>>> + for (auto Prob : BBSuccProbs)
>>>>>>>> + Weights.push_back(Prob.getNumerator());
>>>>>>>>
>>>>>>>> - if (Weights.size() >= 2) {
>>>>>>>> auto TI = BB->getTerminator();
>>>>>>>> TI->setMetadata(
>>>>>>>> LLVMContext::MD_prof,
>>>>>>>>
>>>>>>>> Modified: llvm/trunk/test/Analysis/BranchProbabilityInfo/noreturn.ll
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/BranchProbabilityInfo/noreturn.ll?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/test/Analysis/BranchProbabilityInfo/noreturn.ll
>>>>>>>> (original)
>>>>>>>> +++ llvm/trunk/test/Analysis/BranchProbabilityInfo/noreturn.ll Tue
>>>>>>>> Dec 22 12:56:14 2015
>>>>>>>> @@ -26,11 +26,11 @@ entry:
>>>>>>>> i32 2, label %case_b
>>>>>>>> i32 3, label %case_c
>>>>>>>> i32 4, label %case_d]
>>>>>>>> -; CHECK: edge entry -> exit probability is 0x7fffe000 / 0x80000000
>>>>>>>> = 100.00% [HOT edge]
>>>>>>>> -; CHECK: edge entry -> case_a probability is 0x00000800 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> -; CHECK: edge entry -> case_b probability is 0x00000800 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> -; CHECK: edge entry -> case_c probability is 0x00000800 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> -; CHECK: edge entry -> case_d probability is 0x00000800 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> +; CHECK: edge entry -> exit probability is 0x7ffff800 / 0x80000000
>>>>>>>> = 100.00% [HOT edge]
>>>>>>>> +; CHECK: edge entry -> case_a probability is 0x00000200 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> +; CHECK: edge entry -> case_b probability is 0x00000200 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> +; CHECK: edge entry -> case_c probability is 0x00000200 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>> +; CHECK: edge entry -> case_d probability is 0x00000200 /
>>>>>>>> 0x80000000 = 0.00%
>>>>>>>>
>>>>>>>> case_a:
>>>>>>>> br label %case_b
>>>>>>>>
>>>>>>>> Modified:
>>>>>>>> llvm/trunk/test/Transforms/JumpThreading/update-edge-weight.ll
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/JumpThreading/update-edge-weight.ll?rev=256263&r1=256262&r2=256263&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- llvm/trunk/test/Transforms/JumpThreading/update-edge-weight.ll
>>>>>>>> (original)
>>>>>>>> +++ llvm/trunk/test/Transforms/JumpThreading/update-edge-weight.ll
>>>>>>>> Tue Dec 22 12:56:14 2015
>>>>>>>> @@ -2,7 +2,7 @@
>>>>>>>>
>>>>>>>> ; Test if edge weights are properly updated after jump threading.
>>>>>>>>
>>>>>>>> -; CHECK: !2 = !{!"branch_weights", i32 22, i32 7}
>>>>>>>> +; CHECK: !2 = !{!"branch_weights", i32 1629125526, i32 518358122}
>>>>>>>>
>>>>>>>> define void @foo(i32 %n) !prof !0 {
>>>>>>>> entry:
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> llvm-commits mailing list
>>>>>>>> llvm-commits at lists.llvm.org
>>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>>>>>
>>>>>>>
>>>>>>
>>>>
>
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