// "Loop-Aware SLP in GCC" by Ira Rosen, Dorit Nuzman, Ayal Zaks.
//
//===----------------------------------------------------------------------===//
-#define SV_NAME "slp-vectorizer"
-#define DEBUG_TYPE "SLP"
-
#include "llvm/Transforms/Vectorize.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/VectorUtils.h"
#include <algorithm>
#include <map>
using namespace llvm;
+#define SV_NAME "slp-vectorizer"
+#define DEBUG_TYPE "SLP"
+
static cl::opt<int>
SLPCostThreshold("slp-threshold", cl::init(0), cl::Hidden,
cl::desc("Only vectorize if you gain more than this "
BlockNumbering(BasicBlock *Bb) : BB(Bb), Valid(false) {}
- BlockNumbering() : BB(0), Valid(false) {}
+ BlockNumbering() : BB(nullptr), Valid(false) {}
void numberInstructions() {
unsigned Loc = 0;
static BasicBlock *getSameBlock(ArrayRef<Value *> VL) {
Instruction *I0 = dyn_cast<Instruction>(VL[0]);
if (!I0)
- return 0;
+ return nullptr;
BasicBlock *BB = I0->getParent();
for (int i = 1, e = VL.size(); i < e; i++) {
Instruction *I = dyn_cast<Instruction>(VL[i]);
if (!I)
- return 0;
+ return nullptr;
if (BB != I->getParent())
- return 0;
+ return nullptr;
}
return BB;
}
switch (Kind) {
default:
- MD = 0; // Remove unknown metadata
+ MD = nullptr; // Remove unknown metadata
break;
case LLVMContext::MD_tbaa:
MD = MDNode::getMostGenericTBAA(MD, IMD);
Type *Ty = VL[0]->getType();
for (int i = 1, e = VL.size(); i < e; i++)
if (VL[i]->getType() != Ty)
- return 0;
+ return nullptr;
return Ty;
}
/// A negative number means that this is profitable.
int getTreeCost();
- /// Construct a vectorizable tree that starts at \p Roots and is possibly
- /// used by a reduction of \p RdxOps.
- void buildTree(ArrayRef<Value *> Roots, ValueSet *RdxOps = 0);
+ /// Construct a vectorizable tree that starts at \p Roots, ignoring users for
+ /// the purpose of scheduling and extraction in the \p UserIgnoreLst.
+ void buildTree(ArrayRef<Value *> Roots,
+ ArrayRef<Value *> UserIgnoreLst = None);
/// Clear the internal data structures that are created by 'buildTree'.
void deleteTree() {
- RdxOps = 0;
VectorizableTree.clear();
ScalarToTreeEntry.clear();
MustGather.clear();
bool isFullyVectorizableTinyTree();
struct TreeEntry {
- TreeEntry() : Scalars(), VectorizedValue(0), LastScalarIndex(0),
+ TreeEntry() : Scalars(), VectorizedValue(nullptr), LastScalarIndex(0),
NeedToGather(0) {}
/// \returns true if the scalars in VL are equal to this entry.
/// Numbers instructions in different blocks.
DenseMap<BasicBlock *, BlockNumbering> BlocksNumbers;
- /// Reduction operators.
- ValueSet *RdxOps;
+ /// List of users to ignore during scheduling and that don't need extracting.
+ ArrayRef<Value *> UserIgnoreList;
// Analysis and block reference.
Function *F;
IRBuilder<> Builder;
};
-void BoUpSLP::buildTree(ArrayRef<Value *> Roots, ValueSet *Rdx) {
+void BoUpSLP::buildTree(ArrayRef<Value *> Roots,
+ ArrayRef<Value *> UserIgnoreLst) {
deleteTree();
- RdxOps = Rdx;
+ UserIgnoreList = UserIgnoreLst;
if (!getSameType(Roots))
return;
buildTree_rec(Roots, 0);
if (!UserInst)
continue;
- // Ignore uses that are part of the reduction.
- if (Rdx && std::find(Rdx->begin(), Rdx->end(), UserInst) != Rdx->end())
+ // Ignore users in the user ignore list.
+ if (std::find(UserIgnoreList.begin(), UserIgnoreList.end(), UserInst) !=
+ UserIgnoreList.end())
continue;
DEBUG(dbgs() << "SLP: Need to extract:" << *U << " from lane " <<
continue;
}
- // This user is part of the reduction.
- if (RdxOps && RdxOps->count(UI))
+ // Ignore users in the user ignore list.
+ if (std::find(UserIgnoreList.begin(), UserIgnoreList.end(), UI) !=
+ UserIgnoreList.end())
continue;
// Make sure that we can schedule this unknown user.
case Instruction::Call: {
// Check if the calls are all to the same vectorizable intrinsic.
IntrinsicInst *II = dyn_cast<IntrinsicInst>(VL[0]);
- if (II==NULL) {
+ Intrinsic::ID ID = II ? II->getIntrinsicID() : Intrinsic::not_intrinsic;
+
+ if (!isTriviallyVectorizable(ID)) {
newTreeEntry(VL, false);
DEBUG(dbgs() << "SLP: Non-vectorizable call.\n");
return;
// If instead not all operands are constants, then set the operand kind
// to OK_AnyValue. If all operands are constants but not the same,
// then set the operand kind to OK_NonUniformConstantValue.
- ConstantInt *CInt = NULL;
+ ConstantInt *CInt = nullptr;
for (unsigned i = 0; i < VL.size(); ++i) {
const Instruction *I = cast<Instruction>(VL[i]);
if (!isa<ConstantInt>(I->getOperand(1))) {
return LI->getPointerOperand();
if (StoreInst *SI = dyn_cast<StoreInst>(I))
return SI->getPointerOperand();
- return 0;
+ return nullptr;
}
unsigned BoUpSLP::getAddressSpaceOperand(Value *I) {
if (!A.Ptr || !B.Ptr || AA->alias(A, B))
return I;
}
- return 0;
+ return nullptr;
}
int BoUpSLP::getLastIndex(ArrayRef<Value *> VL) {
if (En->isSame(VL) && En->VectorizedValue)
return En->VectorizedValue;
}
- return 0;
+ return nullptr;
}
Value *BoUpSLP::vectorizeTree(ArrayRef<Value *> VL) {
default:
llvm_unreachable("unknown inst");
}
- return 0;
+ return nullptr;
}
Value *BoUpSLP::vectorizeTree() {
DEBUG(dbgs() << "SLP: \tvalidating user:" << *U << ".\n");
assert((ScalarToTreeEntry.count(U) ||
- // It is legal to replace the reduction users by undef.
- (RdxOps && RdxOps->count(U))) &&
+ // It is legal to replace users in the ignorelist by undef.
+ (std::find(UserIgnoreList.begin(), UserIgnoreList.end(), U) !=
+ UserIgnoreList.end())) &&
"Replacing out-of-tree value with undef");
}
#endif
DT->dominates((*v)->getParent(), In->getParent())) {
In->replaceAllUsesWith(*v);
In->eraseFromParent();
- In = 0;
+ In = nullptr;
break;
}
}
SE = &getAnalysis<ScalarEvolution>();
DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- DL = DLP ? &DLP->getDataLayout() : 0;
+ DL = DLP ? &DLP->getDataLayout() : nullptr;
TTI = &getAnalysis<TargetTransformInfo>();
AA = &getAnalysis<AliasAnalysis>();
LI = &getAnalysis<LoopInfo>();
bool tryToVectorizePair(Value *A, Value *B, BoUpSLP &R);
/// \brief Try to vectorize a list of operands.
+ /// \@param BuildVector A list of users to ignore for the purpose of
+ /// scheduling and that don't need extracting.
/// \returns true if a value was vectorized.
- bool tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R);
+ bool tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R,
+ ArrayRef<Value *> BuildVector = None);
/// \brief Try to vectorize a chain that may start at the operands of \V;
bool tryToVectorize(BinaryOperator *V, BoUpSLP &R);
return tryToVectorizeList(VL, R);
}
-bool SLPVectorizer::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R) {
+bool SLPVectorizer::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R,
+ ArrayRef<Value *> BuildVector) {
if (VL.size() < 2)
return false;
bool Changed = false;
- // Keep track of values that were delete by vectorizing in the loop below.
+ // Keep track of values that were deleted by vectorizing in the loop below.
SmallVector<WeakVH, 8> TrackValues(VL.begin(), VL.end());
for (unsigned i = 0, e = VL.size(); i < e; ++i) {
<< "\n");
ArrayRef<Value *> Ops = VL.slice(i, OpsWidth);
- R.buildTree(Ops);
+ ArrayRef<Value *> BuildVectorSlice;
+ if (!BuildVector.empty())
+ BuildVectorSlice = BuildVector.slice(i, OpsWidth);
+
+ R.buildTree(Ops, BuildVectorSlice);
int Cost = R.getTreeCost();
if (Cost < -SLPCostThreshold) {
DEBUG(dbgs() << "SLP: Vectorizing list at cost:" << Cost << ".\n");
- R.vectorizeTree();
-
+ Value *VectorizedRoot = R.vectorizeTree();
+
+ // Reconstruct the build vector by extracting the vectorized root. This
+ // way we handle the case where some elements of the vector are undefined.
+ // (return (inserelt <4 xi32> (insertelt undef (opd0) 0) (opd1) 2))
+ if (!BuildVectorSlice.empty()) {
+ Instruction *InsertAfter = cast<Instruction>(VectorizedRoot);
+ for (auto &V : BuildVectorSlice) {
+ InsertElementInst *IE = cast<InsertElementInst>(V);
+ IRBuilder<> Builder(++BasicBlock::iterator(InsertAfter));
+ Instruction *Extract = cast<Instruction>(
+ Builder.CreateExtractElement(VectorizedRoot, IE->getOperand(2)));
+ IE->setOperand(1, Extract);
+ IE->removeFromParent();
+ IE->insertAfter(Extract);
+ InsertAfter = IE;
+ }
+ }
// Move to the next bundle.
i += VF - 1;
Changed = true;
/// *p =
///
class HorizontalReduction {
- SmallPtrSet<Value *, 16> ReductionOps;
+ SmallVector<Value *, 16> ReductionOps;
SmallVector<Value *, 32> ReducedVals;
BinaryOperator *ReductionRoot;
public:
HorizontalReduction()
- : ReductionRoot(0), ReductionPHI(0), ReductionOpcode(0),
+ : ReductionRoot(nullptr), ReductionPHI(nullptr), ReductionOpcode(0),
ReducedValueOpcode(0), ReduxWidth(0), IsPairwiseReduction(false) {}
/// \brief Try to find a reduction tree.
// In such a case start looking for a tree rooted in the first '+'.
if (Phi) {
if (B->getOperand(0) == Phi) {
- Phi = 0;
+ Phi = nullptr;
B = dyn_cast<BinaryOperator>(B->getOperand(1));
} else if (B->getOperand(1) == Phi) {
- Phi = 0;
+ Phi = nullptr;
B = dyn_cast<BinaryOperator>(B->getOperand(0));
}
}
// We need to be able to reassociate the adds.
if (!TreeN->isAssociative())
return false;
- ReductionOps.insert(TreeN);
+ ReductionOps.push_back(TreeN);
}
// Retract.
Stack.pop_back();
if (NumReducedVals < ReduxWidth)
return false;
- Value *VectorizedTree = 0;
+ Value *VectorizedTree = nullptr;
IRBuilder<> Builder(ReductionRoot);
FastMathFlags Unsafe;
Unsafe.setUnsafeAlgebra();
for (; i < NumReducedVals - ReduxWidth + 1; i += ReduxWidth) {
ArrayRef<Value *> ValsToReduce(&ReducedVals[i], ReduxWidth);
- V.buildTree(ValsToReduce, &ReductionOps);
+ V.buildTree(ValsToReduce, ReductionOps);
// Estimate cost.
int Cost = V.getTreeCost() + getReductionCost(TTI, ReducedVals[i]);
}
// Update users.
if (ReductionPHI) {
- assert(ReductionRoot != NULL && "Need a reduction operation");
+ assert(ReductionRoot && "Need a reduction operation");
ReductionRoot->setOperand(0, VectorizedTree);
ReductionRoot->setOperand(1, ReductionPHI);
} else
ReductionRoot->replaceAllUsesWith(VectorizedTree);
}
- return VectorizedTree != 0;
+ return VectorizedTree != nullptr;
}
private:
///
/// Returns true if it matches
///
-static bool findBuildVector(InsertElementInst *IE,
- SmallVectorImpl<Value *> &Ops) {
- if (!isa<UndefValue>(IE->getOperand(0)))
+static bool findBuildVector(InsertElementInst *FirstInsertElem,
+ SmallVectorImpl<Value *> &BuildVector,
+ SmallVectorImpl<Value *> &BuildVectorOpds) {
+ if (!isa<UndefValue>(FirstInsertElem->getOperand(0)))
return false;
+ InsertElementInst *IE = FirstInsertElem;
while (true) {
- Ops.push_back(IE->getOperand(1));
+ BuildVector.push_back(IE);
+ BuildVectorOpds.push_back(IE->getOperand(1));
if (IE->use_empty())
return false;
Value *Rdx =
(P->getIncomingBlock(0) == BB
? (P->getIncomingValue(0))
- : (P->getIncomingBlock(1) == BB ? P->getIncomingValue(1) : 0));
+ : (P->getIncomingBlock(1) == BB ? P->getIncomingValue(1)
+ : nullptr));
// Check if this is a Binary Operator.
BinaryOperator *BI = dyn_cast_or_null<BinaryOperator>(Rdx);
if (!BI)
if (BinaryOperator *BinOp =
dyn_cast<BinaryOperator>(SI->getValueOperand())) {
HorizontalReduction HorRdx;
- if (((HorRdx.matchAssociativeReduction(0, BinOp, DL) &&
+ if (((HorRdx.matchAssociativeReduction(nullptr, BinOp, DL) &&
HorRdx.tryToReduce(R, TTI)) ||
tryToVectorize(BinOp, R))) {
Changed = true;
}
// Try to vectorize trees that start at insertelement instructions.
- if (InsertElementInst *IE = dyn_cast<InsertElementInst>(it)) {
- SmallVector<Value *, 8> Ops;
- if (!findBuildVector(IE, Ops))
+ if (InsertElementInst *FirstInsertElem = dyn_cast<InsertElementInst>(it)) {
+ SmallVector<Value *, 16> BuildVector;
+ SmallVector<Value *, 16> BuildVectorOpds;
+ if (!findBuildVector(FirstInsertElem, BuildVector, BuildVectorOpds))
continue;
- if (tryToVectorizeList(Ops, R)) {
+ // Vectorize starting with the build vector operands ignoring the
+ // BuildVector instructions for the purpose of scheduling and user
+ // extraction.
+ if (tryToVectorizeList(BuildVectorOpds, R, BuildVector)) {
Changed = true;
it = BB->begin();
e = BB->end();