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[CHR] Clean up some code and reduce copying. NFCI.
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@d0k
d0k committed Apr 13, 2020
1 parent 4d4fef2 commit f1542ef
Showing 1 changed file with 66 additions and 74 deletions.
140 changes: 66 additions & 74 deletions llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
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Expand Up @@ -221,10 +221,8 @@ class CHRScope {
"Must be siblings");
assert(getExitBlock() == Next->getEntryBlock() &&
"Must be adjacent");
for (RegInfo &RI : Next->RegInfos)
RegInfos.push_back(RI);
for (CHRScope *Sub : Next->Subs)
Subs.push_back(Sub);
RegInfos.append(Next->RegInfos.begin(), Next->RegInfos.end());
Subs.append(Next->Subs.begin(), Next->Subs.end());
}

void addSub(CHRScope *SubIn) {
Expand All @@ -246,37 +244,36 @@ class CHRScope {
assert(Boundary && "Boundary null");
assert(RegInfos.begin()->R != Boundary &&
"Can't be split at beginning");
auto BoundaryIt = std::find_if(RegInfos.begin(), RegInfos.end(),
[&Boundary](const RegInfo& RI) {
return Boundary == RI.R;
});
auto BoundaryIt = llvm::find_if(
RegInfos, [&Boundary](const RegInfo &RI) { return Boundary == RI.R; });
if (BoundaryIt == RegInfos.end())
return nullptr;
SmallVector<RegInfo, 8> TailRegInfos;
SmallVector<CHRScope *, 8> TailSubs;
TailRegInfos.insert(TailRegInfos.begin(), BoundaryIt, RegInfos.end());
RegInfos.resize(BoundaryIt - RegInfos.begin());
ArrayRef<RegInfo> TailRegInfos(BoundaryIt, RegInfos.end());
DenseSet<Region *> TailRegionSet;
for (RegInfo &RI : TailRegInfos)
for (const RegInfo &RI : TailRegInfos)
TailRegionSet.insert(RI.R);
for (auto It = Subs.begin(); It != Subs.end(); ) {
CHRScope *Sub = *It;
assert(Sub && "null Sub");
Region *Parent = Sub->getParentRegion();
if (TailRegionSet.count(Parent)) {
TailSubs.push_back(Sub);
It = Subs.erase(It);
} else {
assert(std::find_if(RegInfos.begin(), RegInfos.end(),
[&Parent](const RegInfo& RI) {
return Parent == RI.R;
}) != RegInfos.end() &&
"Must be in head");
++It;
}
}

auto TailIt =
std::stable_partition(Subs.begin(), Subs.end(), [&](CHRScope *Sub) {
assert(Sub && "null Sub");
Region *Parent = Sub->getParentRegion();
if (TailRegionSet.count(Parent))
return false;

assert(llvm::find_if(RegInfos,
[&Parent](const RegInfo &RI) {
return Parent == RI.R;
}) != RegInfos.end() &&
"Must be in head");
return true;
});
ArrayRef<CHRScope *> TailSubs(TailIt, Subs.end());

assert(HoistStopMap.empty() && "MapHoistStops must be empty");
return new CHRScope(TailRegInfos, TailSubs);
auto *Scope = new CHRScope(TailRegInfos, TailSubs);
RegInfos.erase(BoundaryIt, RegInfos.end());
Subs.erase(TailIt, Subs.end());
return Scope;
}

bool contains(Instruction *I) const {
Expand Down Expand Up @@ -314,9 +311,9 @@ class CHRScope {
HoistStopMapTy HoistStopMap;

private:
CHRScope(SmallVector<RegInfo, 8> &RegInfosIn,
SmallVector<CHRScope *, 8> &SubsIn)
: RegInfos(RegInfosIn), Subs(SubsIn), BranchInsertPoint(nullptr) {}
CHRScope(ArrayRef<RegInfo> RegInfosIn, ArrayRef<CHRScope *> SubsIn)
: RegInfos(RegInfosIn.begin(), RegInfosIn.end()),
Subs(SubsIn.begin(), SubsIn.end()), BranchInsertPoint(nullptr) {}
};

class CHR {
Expand All @@ -340,8 +337,7 @@ class CHR {

void findScopes(SmallVectorImpl<CHRScope *> &Output) {
Region *R = RI.getTopLevelRegion();
CHRScope *Scope = findScopes(R, nullptr, nullptr, Output);
if (Scope) {
if (CHRScope *Scope = findScopes(R, nullptr, nullptr, Output)) {
Output.push_back(Scope);
}
}
Expand Down Expand Up @@ -514,39 +510,36 @@ static bool isHoistable(Instruction *I, DominatorTree &DT) {
// first-region entry block) or the (hoistable or unhoistable) base values that
// are defined outside (including the first-region entry block) of the
// scope. The returned set doesn't include constants.
static std::set<Value *> getBaseValues(
Value *V, DominatorTree &DT,
DenseMap<Value *, std::set<Value *>> &Visited) {
if (Visited.count(V)) {
return Visited[V];
static const std::set<Value *> &
getBaseValues(Value *V, DominatorTree &DT,
DenseMap<Value *, std::set<Value *>> &Visited) {
auto It = Visited.find(V);
if (It != Visited.end()) {
return It->second;
}
std::set<Value *> Result;
if (auto *I = dyn_cast<Instruction>(V)) {
// We don't stop at a block that's not in the Scope because we would miss some
// instructions that are based on the same base values if we stop there.
// We don't stop at a block that's not in the Scope because we would miss
// some instructions that are based on the same base values if we stop
// there.
if (!isHoistable(I, DT)) {
Result.insert(I);
Visited.insert(std::make_pair(V, Result));
return Result;
return Visited.insert(std::make_pair(V, std::move(Result))).first->second;
}
// I is hoistable above the Scope.
for (Value *Op : I->operands()) {
std::set<Value *> OpResult = getBaseValues(Op, DT, Visited);
const std::set<Value *> &OpResult = getBaseValues(Op, DT, Visited);
Result.insert(OpResult.begin(), OpResult.end());
}
Visited.insert(std::make_pair(V, Result));
return Result;
return Visited.insert(std::make_pair(V, std::move(Result))).first->second;
}
if (isa<Argument>(V)) {
Result.insert(V);
Visited.insert(std::make_pair(V, Result));
return Result;
}
// We don't include others like constants because those won't lead to any
// chance of folding of conditions (eg two bit checks merged into one check)
// after CHR.
Visited.insert(std::make_pair(V, Result));
return Result; // empty
return Visited.insert(std::make_pair(V, std::move(Result))).first->second;
}

// Return true if V is already hoisted or can be hoisted (along with its
Expand All @@ -560,8 +553,9 @@ checkHoistValue(Value *V, Instruction *InsertPoint, DominatorTree &DT,
DenseMap<Instruction *, bool> &Visited) {
assert(InsertPoint && "Null InsertPoint");
if (auto *I = dyn_cast<Instruction>(V)) {
if (Visited.count(I)) {
return Visited[I];
auto It = Visited.find(I);
if (It != Visited.end()) {
return It->second;
}
assert(DT.getNode(I->getParent()) && "DT must contain I's parent block");
assert(DT.getNode(InsertPoint->getParent()) && "DT must contain Destination");
Expand Down Expand Up @@ -1094,11 +1088,11 @@ static bool shouldSplit(Instruction *InsertPoint,
std::set<Value *> PrevBases, Bases;
DenseMap<Value *, std::set<Value *>> Visited;
for (Value *V : PrevConditionValues) {
std::set<Value *> BaseValues = getBaseValues(V, DT, Visited);
const std::set<Value *> &BaseValues = getBaseValues(V, DT, Visited);
PrevBases.insert(BaseValues.begin(), BaseValues.end());
}
for (Value *V : ConditionValues) {
std::set<Value *> BaseValues = getBaseValues(V, DT, Visited);
const std::set<Value *> &BaseValues = getBaseValues(V, DT, Visited);
Bases.insert(BaseValues.begin(), BaseValues.end());
}
CHR_DEBUG(
Expand All @@ -1111,10 +1105,9 @@ static bool shouldSplit(Instruction *InsertPoint,
dbgs() << *V << ", ";
}
dbgs() << "\n");
std::set<Value *> Intersection;
std::set_intersection(PrevBases.begin(), PrevBases.end(),
Bases.begin(), Bases.end(),
std::inserter(Intersection, Intersection.begin()));
std::vector<Value *> Intersection;
std::set_intersection(PrevBases.begin(), PrevBases.end(), Bases.begin(),
Bases.end(), std::back_inserter(Intersection));
if (Intersection.empty()) {
// Empty intersection, split.
CHR_DEBUG(dbgs() << "Split. Intersection empty\n");
Expand Down Expand Up @@ -1439,7 +1432,7 @@ void CHR::setCHRRegions(CHRScope *Scope, CHRScope *OutermostScope) {
setCHRRegions(Sub, OutermostScope);
}

bool CHRScopeSorter(CHRScope *Scope1, CHRScope *Scope2) {
static bool CHRScopeSorter(CHRScope *Scope1, CHRScope *Scope2) {
return Scope1->RegInfos[0].R->getDepth() < Scope2->RegInfos[0].R->getDepth();
}

Expand Down Expand Up @@ -1578,26 +1571,24 @@ static bool negateICmpIfUsedByBranchOrSelectOnly(ICmpInst *ICmp,
static void insertTrivialPHIs(CHRScope *Scope,
BasicBlock *EntryBlock, BasicBlock *ExitBlock,
DenseSet<PHINode *> &TrivialPHIs) {
DenseSet<BasicBlock *> BlocksInScopeSet;
SmallVector<BasicBlock *, 8> BlocksInScopeVec;
SmallSetVector<BasicBlock *, 8> BlocksInScope;
for (RegInfo &RI : Scope->RegInfos) {
for (BasicBlock *BB : RI.R->blocks()) { // This includes the blocks in the
// sub-Scopes.
BlocksInScopeSet.insert(BB);
BlocksInScopeVec.push_back(BB);
BlocksInScope.insert(BB);
}
}
CHR_DEBUG(
dbgs() << "Inserting redudant phis\n";
for (BasicBlock *BB : BlocksInScopeVec) {
dbgs() << "BlockInScope " << BB->getName() << "\n";
});
for (BasicBlock *BB : BlocksInScopeVec) {
CHR_DEBUG({
dbgs() << "Inserting redundant phis\n";
for (BasicBlock *BB : BlocksInScope)
dbgs() << "BlockInScope " << BB->getName() << "\n";
});
for (BasicBlock *BB : BlocksInScope) {
for (Instruction &I : *BB) {
SmallVector<Instruction *, 8> Users;
for (User *U : I.users()) {
if (auto *UI = dyn_cast<Instruction>(U)) {
if (BlocksInScopeSet.count(UI->getParent()) == 0 &&
if (BlocksInScope.count(UI->getParent()) == 0 &&
// Unless there's already a phi for I at the exit block.
!(isa<PHINode>(UI) && UI->getParent() == ExitBlock)) {
CHR_DEBUG(dbgs() << "V " << I << "\n");
Expand Down Expand Up @@ -1874,9 +1865,10 @@ void CHR::fixupBranchesAndSelects(CHRScope *Scope,
<< " branches or selects";
});
MergedBR->setCondition(MergedCondition);
SmallVector<uint32_t, 2> Weights;
Weights.push_back(static_cast<uint32_t>(CHRBranchBias.scale(1000)));
Weights.push_back(static_cast<uint32_t>(CHRBranchBias.getCompl().scale(1000)));
uint32_t Weights[] = {
static_cast<uint32_t>(CHRBranchBias.scale(1000)),
static_cast<uint32_t>(CHRBranchBias.getCompl().scale(1000)),
};
MDBuilder MDB(F.getContext());
MergedBR->setMetadata(LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
CHR_DEBUG(dbgs() << "CHR branch bias " << Weights[0] << ":" << Weights[1]
Expand Down

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