//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Vectorize.h"
#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/Optional.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/Optional.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/VectorUtils.h"
+#include "llvm/Analysis/VectorUtils.h"
#include <algorithm>
#include <map>
#include <memory>
cl::desc(
"Attempt to vectorize horizontal reductions feeding into a store"));
+static cl::opt<int>
+MaxVectorRegSizeOption("slp-max-reg-size", cl::init(128), cl::Hidden,
+ cl::desc("Attempt to vectorize for this register size in bits"));
+
+/// Limits the size of scheduling regions in a block.
+/// It avoid long compile times for _very_ large blocks where vector
+/// instructions are spread over a wide range.
+/// This limit is way higher than needed by real-world functions.
+static cl::opt<int>
+ScheduleRegionSizeBudget("slp-schedule-budget", cl::init(100000), cl::Hidden,
+ cl::desc("Limit the size of the SLP scheduling region per block"));
+
namespace {
+// FIXME: Set this via cl::opt to allow overriding.
static const unsigned MinVecRegSize = 128;
static const unsigned RecursionMaxDepth = 12;
+// Limit the number of alias checks. The limit is chosen so that
+// it has no negative effect on the llvm benchmarks.
+static const unsigned AliasedCheckLimit = 10;
+
+// Another limit for the alias checks: The maximum distance between load/store
+// instructions where alias checks are done.
+// This limit is useful for very large basic blocks.
+static const unsigned MaxMemDepDistance = 160;
+
+/// If the ScheduleRegionSizeBudget is exhausted, we allow small scheduling
+/// regions to be handled.
+static const int MinScheduleRegionSize = 16;
+
+/// \brief Predicate for the element types that the SLP vectorizer supports.
+///
+/// The most important thing to filter here are types which are invalid in LLVM
+/// vectors. We also filter target specific types which have absolutely no
+/// meaningful vectorization path such as x86_fp80 and ppc_f128. This just
+/// avoids spending time checking the cost model and realizing that they will
+/// be inevitably scalarized.
+static bool isValidElementType(Type *Ty) {
+ return VectorType::isValidElementType(Ty) && !Ty->isX86_FP80Ty() &&
+ !Ty->isPPC_FP128Ty();
+}
+
/// \returns the parent basic block if all of the instructions in \p VL
/// are in the same block or null otherwise.
static BasicBlock *getSameBlock(ArrayRef<Value *> VL) {
return false;
}
-/// \returns ShuffleVector instruction if intructions in \p VL have
+/// \returns ShuffleVector instruction if instructions in \p VL have
/// alternate fadd,fsub / fsub,fadd/add,sub/sub,add sequence.
/// (i.e. e.g. opcodes of fadd,fsub,fadd,fsub...)
static unsigned isAltInst(ArrayRef<Value *> VL) {
MD = MDNode::getMostGenericTBAA(MD, IMD);
break;
case LLVMContext::MD_alias_scope:
+ MD = MDNode::getMostGenericAliasScope(MD, IMD);
+ break;
case LLVMContext::MD_noalias:
MD = MDNode::intersect(MD, IMD);
break;
case LLVMContext::MD_fpmath:
MD = MDNode::getMostGenericFPMath(MD, IMD);
break;
+ case LLVMContext::MD_nontemporal:
+ MD = MDNode::intersect(MD, IMD);
+ break;
}
}
I->setMetadata(Kind, MD);
return true;
}
-static void reorderInputsAccordingToOpcode(ArrayRef<Value *> VL,
- SmallVectorImpl<Value *> &Left,
- SmallVectorImpl<Value *> &Right) {
-
- SmallVector<Value *, 16> OrigLeft, OrigRight;
-
- bool AllSameOpcodeLeft = true;
- bool AllSameOpcodeRight = true;
- for (unsigned i = 0, e = VL.size(); i != e; ++i) {
- Instruction *I = cast<Instruction>(VL[i]);
- Value *V0 = I->getOperand(0);
- Value *V1 = I->getOperand(1);
-
- OrigLeft.push_back(V0);
- OrigRight.push_back(V1);
-
- Instruction *I0 = dyn_cast<Instruction>(V0);
- Instruction *I1 = dyn_cast<Instruction>(V1);
-
- // Check whether all operands on one side have the same opcode. In this case
- // we want to preserve the original order and not make things worse by
- // reordering.
- AllSameOpcodeLeft = I0;
- AllSameOpcodeRight = I1;
-
- if (i && AllSameOpcodeLeft) {
- if(Instruction *P0 = dyn_cast<Instruction>(OrigLeft[i-1])) {
- if(P0->getOpcode() != I0->getOpcode())
- AllSameOpcodeLeft = false;
- } else
- AllSameOpcodeLeft = false;
- }
- if (i && AllSameOpcodeRight) {
- if(Instruction *P1 = dyn_cast<Instruction>(OrigRight[i-1])) {
- if(P1->getOpcode() != I1->getOpcode())
- AllSameOpcodeRight = false;
- } else
- AllSameOpcodeRight = false;
- }
-
- // Sort two opcodes. In the code below we try to preserve the ability to use
- // broadcast of values instead of individual inserts.
- // vl1 = load
- // vl2 = phi
- // vr1 = load
- // vr2 = vr2
- // = vl1 x vr1
- // = vl2 x vr2
- // If we just sorted according to opcode we would leave the first line in
- // tact but we would swap vl2 with vr2 because opcode(phi) > opcode(load).
- // = vl1 x vr1
- // = vr2 x vl2
- // Because vr2 and vr1 are from the same load we loose the opportunity of a
- // broadcast for the packed right side in the backend: we have [vr1, vl2]
- // instead of [vr1, vr2=vr1].
- if (I0 && I1) {
- if(!i && I0->getOpcode() > I1->getOpcode()) {
- Left.push_back(I1);
- Right.push_back(I0);
- } else if (i && I0->getOpcode() > I1->getOpcode() && Right[i-1] != I1) {
- // Try not to destroy a broad cast for no apparent benefit.
- Left.push_back(I1);
- Right.push_back(I0);
- } else if (i && I0->getOpcode() == I1->getOpcode() && Right[i-1] == I0) {
- // Try preserve broadcasts.
- Left.push_back(I1);
- Right.push_back(I0);
- } else if (i && I0->getOpcode() == I1->getOpcode() && Left[i-1] == I1) {
- // Try preserve broadcasts.
- Left.push_back(I1);
- Right.push_back(I0);
- } else {
- Left.push_back(I0);
- Right.push_back(I1);
- }
- continue;
- }
- // One opcode, put the instruction on the right.
- if (I0) {
- Left.push_back(V1);
- Right.push_back(I0);
- continue;
- }
- Left.push_back(V0);
- Right.push_back(V1);
- }
-
- bool LeftBroadcast = isSplat(Left);
- bool RightBroadcast = isSplat(Right);
-
- // Don't reorder if the operands where good to begin with.
- if (!(LeftBroadcast || RightBroadcast) &&
- (AllSameOpcodeRight || AllSameOpcodeLeft)) {
- Left = OrigLeft;
- Right = OrigRight;
- }
-}
-
/// \returns True if in-tree use also needs extract. This refers to
/// possible scalar operand in vectorized instruction.
static bool InTreeUserNeedToExtract(Value *Scalar, Instruction *UserInst,
}
/// \returns the AA location that is being access by the instruction.
-static AliasAnalysis::Location getLocation(Instruction *I, AliasAnalysis *AA) {
+static MemoryLocation getLocation(Instruction *I, AliasAnalysis *AA) {
if (StoreInst *SI = dyn_cast<StoreInst>(I))
- return AA->getLocation(SI);
+ return MemoryLocation::get(SI);
+ if (LoadInst *LI = dyn_cast<LoadInst>(I))
+ return MemoryLocation::get(LI);
+ return MemoryLocation();
+}
+
+/// \returns True if the instruction is not a volatile or atomic load/store.
+static bool isSimple(Instruction *I) {
if (LoadInst *LI = dyn_cast<LoadInst>(I))
- return AA->getLocation(LI);
- return AliasAnalysis::Location();
+ return LI->isSimple();
+ if (StoreInst *SI = dyn_cast<StoreInst>(I))
+ return SI->isSimple();
+ if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I))
+ return !MI->isVolatile();
+ return true;
}
/// Bottom Up SLP Vectorizer.
typedef SmallPtrSet<Value *, 16> ValueSet;
typedef SmallVector<StoreInst *, 8> StoreList;
- BoUpSLP(Function *Func, ScalarEvolution *Se, const DataLayout *Dl,
- TargetTransformInfo *Tti, TargetLibraryInfo *TLi, AliasAnalysis *Aa,
- LoopInfo *Li, DominatorTree *Dt, AssumptionCache *AC)
+ BoUpSLP(Function *Func, ScalarEvolution *Se, TargetTransformInfo *Tti,
+ TargetLibraryInfo *TLi, AliasAnalysis *Aa, LoopInfo *Li,
+ DominatorTree *Dt, AssumptionCache *AC)
: NumLoadsWantToKeepOrder(0), NumLoadsWantToChangeOrder(0), F(Func),
- SE(Se), DL(Dl), TTI(Tti), TLI(TLi), AA(Aa), LI(Li), DT(Dt),
+ SE(Se), TTI(Tti), TLI(TLi), AA(Aa), LI(Li), DT(Dt),
Builder(Se->getContext()) {
CodeMetrics::collectEphemeralValues(F, AC, EphValues);
}
}
/// \returns true if the memory operations A and B are consecutive.
- bool isConsecutiveAccess(Value *A, Value *B);
+ bool isConsecutiveAccess(Value *A, Value *B, const DataLayout &DL);
/// \brief Perform LICM and CSE on the newly generated gather sequences.
void optimizeGatherSequence();
- /// \returns true if it is benefitial to reverse the vector order.
+ /// \returns true if it is beneficial to reverse the vector order.
bool shouldReorder() const {
return NumLoadsWantToChangeOrder > NumLoadsWantToKeepOrder;
}
/// \returns a vector from a collection of scalars in \p VL.
Value *Gather(ArrayRef<Value *> VL, VectorType *Ty);
- /// \returns whether the VectorizableTree is fully vectoriable and will
+ /// \returns whether the VectorizableTree is fully vectorizable and will
/// be beneficial even the tree height is tiny.
bool isFullyVectorizableTinyTree();
+ /// \reorder commutative operands in alt shuffle if they result in
+ /// vectorized code.
+ void reorderAltShuffleOperands(ArrayRef<Value *> VL,
+ SmallVectorImpl<Value *> &Left,
+ SmallVectorImpl<Value *> &Right);
+ /// \reorder commutative operands to get better probability of
+ /// generating vectorized code.
+ void reorderInputsAccordingToOpcode(ArrayRef<Value *> VL,
+ SmallVectorImpl<Value *> &Left,
+ SmallVectorImpl<Value *> &Right);
struct TreeEntry {
TreeEntry() : Scalars(), VectorizedValue(nullptr),
NeedToGather(0) {}
/// Create a new VectorizableTree entry.
TreeEntry *newTreeEntry(ArrayRef<Value *> VL, bool Vectorized) {
- VectorizableTree.push_back(TreeEntry());
+ VectorizableTree.emplace_back();
int idx = VectorizableTree.size() - 1;
TreeEntry *Last = &VectorizableTree[idx];
Last->Scalars.insert(Last->Scalars.begin(), VL.begin(), VL.end());
/// This POD struct describes one external user in the vectorized tree.
struct ExternalUser {
ExternalUser (Value *S, llvm::User *U, int L) :
- Scalar(S), User(U), Lane(L){};
+ Scalar(S), User(U), Lane(L){}
// Which scalar in our function.
Value *Scalar;
// Which user that uses the scalar.
///
/// \p Loc1 is the location of \p Inst1. It is passed explicitly because it
/// is invariant in the calling loop.
- bool isAliased(const AliasAnalysis::Location &Loc1, Instruction *Inst1,
+ bool isAliased(const MemoryLocation &Loc1, Instruction *Inst1,
Instruction *Inst2) {
// First check if the result is already in the cache.
if (result.hasValue()) {
return result.getValue();
}
- AliasAnalysis::Location Loc2 = getLocation(Inst2, AA);
+ MemoryLocation Loc2 = getLocation(Inst2, AA);
bool aliased = true;
- if (Loc1.Ptr && Loc2.Ptr) {
+ if (Loc1.Ptr && Loc2.Ptr && isSimple(Inst1) && isSimple(Inst2)) {
// Do the alias check.
aliased = AA->alias(Loc1, Loc2);
}
: BB(BB), ChunkSize(BB->size()), ChunkPos(ChunkSize),
ScheduleStart(nullptr), ScheduleEnd(nullptr),
FirstLoadStoreInRegion(nullptr), LastLoadStoreInRegion(nullptr),
+ ScheduleRegionSize(0),
+ ScheduleRegionSizeLimit(ScheduleRegionSizeBudget),
// Make sure that the initial SchedulingRegionID is greater than the
// initial SchedulingRegionID in ScheduleData (which is 0).
SchedulingRegionID(1) {}
FirstLoadStoreInRegion = nullptr;
LastLoadStoreInRegion = nullptr;
+ // Reduce the maximum schedule region size by the size of the
+ // previous scheduling run.
+ ScheduleRegionSizeLimit -= ScheduleRegionSize;
+ if (ScheduleRegionSizeLimit < MinScheduleRegionSize)
+ ScheduleRegionSizeLimit = MinScheduleRegionSize;
+ ScheduleRegionSize = 0;
+
// Make a new scheduling region, i.e. all existing ScheduleData is not
// in the new region yet.
++SchedulingRegionID;
void cancelScheduling(ArrayRef<Value *> VL);
/// Extends the scheduling region so that V is inside the region.
- void extendSchedulingRegion(Value *V);
+ /// \returns true if the region size is within the limit.
+ bool extendSchedulingRegion(Value *V);
/// Initialize the ScheduleData structures for new instructions in the
/// scheduling region.
/// (can be null).
ScheduleData *LastLoadStoreInRegion;
+ /// The current size of the scheduling region.
+ int ScheduleRegionSize;
+
+ /// The maximum size allowed for the scheduling region.
+ int ScheduleRegionSizeLimit;
+
/// The ID of the scheduling region. For a new vectorization iteration this
/// is incremented which "removes" all ScheduleData from the region.
int SchedulingRegionID;
// Analysis and block reference.
Function *F;
ScalarEvolution *SE;
- const DataLayout *DL;
TargetTransformInfo *TTI;
TargetLibraryInfo *TLI;
AliasAnalysis *AA;
if (!BS.tryScheduleBundle(VL, this)) {
DEBUG(dbgs() << "SLP: We are not able to schedule this bundle!\n");
- BS.cancelScheduling(VL);
+ assert((!BS.getScheduleData(VL[0]) ||
+ !BS.getScheduleData(VL[0])->isPartOfBundle()) &&
+ "tryScheduleBundle should cancelScheduling on failure");
newTreeEntry(VL, false);
return;
}
return;
}
case Instruction::Load: {
+ // Check that a vectorized load would load the same memory as a scalar
+ // load.
+ // For example we don't want vectorize loads that are smaller than 8 bit.
+ // Even though we have a packed struct {<i2, i2, i2, i2>} LLVM treats
+ // loading/storing it as an i8 struct. If we vectorize loads/stores from
+ // such a struct we read/write packed bits disagreeing with the
+ // unvectorized version.
+ const DataLayout &DL = F->getParent()->getDataLayout();
+ Type *ScalarTy = VL[0]->getType();
+
+ if (DL.getTypeSizeInBits(ScalarTy) !=
+ DL.getTypeAllocSizeInBits(ScalarTy)) {
+ BS.cancelScheduling(VL);
+ newTreeEntry(VL, false);
+ DEBUG(dbgs() << "SLP: Gathering loads of non-packed type.\n");
+ return;
+ }
// Check if the loads are consecutive or of we need to swizzle them.
for (unsigned i = 0, e = VL.size() - 1; i < e; ++i) {
LoadInst *L = cast<LoadInst>(VL[i]);
DEBUG(dbgs() << "SLP: Gathering non-simple loads.\n");
return;
}
- if (!isConsecutiveAccess(VL[i], VL[i + 1])) {
- if (VL.size() == 2 && isConsecutiveAccess(VL[1], VL[0])) {
+
+ if (!isConsecutiveAccess(VL[i], VL[i + 1], DL)) {
+ if (VL.size() == 2 && isConsecutiveAccess(VL[1], VL[0], DL)) {
++NumLoadsWantToChangeOrder;
}
BS.cancelScheduling(VL);
Type *SrcTy = VL0->getOperand(0)->getType();
for (unsigned i = 0; i < VL.size(); ++i) {
Type *Ty = cast<Instruction>(VL[i])->getOperand(0)->getType();
- if (Ty != SrcTy || Ty->isAggregateType() || Ty->isVectorTy()) {
+ if (Ty != SrcTy || !isValidElementType(Ty)) {
BS.cancelScheduling(VL);
newTreeEntry(VL, false);
DEBUG(dbgs() << "SLP: Gathering casts with different src types.\n");
case Instruction::ICmp:
case Instruction::FCmp: {
// Check that all of the compares have the same predicate.
- CmpInst::Predicate P0 = dyn_cast<CmpInst>(VL0)->getPredicate();
+ CmpInst::Predicate P0 = cast<CmpInst>(VL0)->getPredicate();
Type *ComparedTy = cast<Instruction>(VL[0])->getOperand(0)->getType();
for (unsigned i = 1, e = VL.size(); i < e; ++i) {
CmpInst *Cmp = cast<CmpInst>(VL[i]);
return;
}
case Instruction::Store: {
+ const DataLayout &DL = F->getParent()->getDataLayout();
// Check if the stores are consecutive or of we need to swizzle them.
for (unsigned i = 0, e = VL.size() - 1; i < e; ++i)
- if (!isConsecutiveAccess(VL[i], VL[i + 1])) {
+ if (!isConsecutiveAccess(VL[i], VL[i + 1], DL)) {
BS.cancelScheduling(VL);
newTreeEntry(VL, false);
DEBUG(dbgs() << "SLP: Non-consecutive store.\n");
}
newTreeEntry(VL, true);
DEBUG(dbgs() << "SLP: added a ShuffleVector op.\n");
+
+ // Reorder operands if reordering would enable vectorization.
+ if (isa<BinaryOperator>(VL0)) {
+ ValueList Left, Right;
+ reorderAltShuffleOperands(VL, Left, Right);
+ buildTree_rec(Left, Depth + 1);
+ buildTree_rec(Right, Depth + 1);
+ return;
+ }
+
for (unsigned i = 0, e = VL0->getNumOperands(); i < e; ++i) {
ValueList Operands;
// Prepare the operand vector.
if (VectorizableTree.size() != 2)
return false;
- // Handle splat stores.
- if (!VectorizableTree[0].NeedToGather && isSplat(VectorizableTree[1].Scalars))
+ // Handle splat and all-constants stores.
+ if (!VectorizableTree[0].NeedToGather &&
+ (allConstant(VectorizableTree[1].Scalars) ||
+ isSplat(VectorizableTree[1].Scalars)))
return true;
// Gathering cost would be too much for tiny trees.
}
// Now find the sequence of instructions between PrevInst and Inst.
- BasicBlock::reverse_iterator InstIt(Inst), PrevInstIt(PrevInst);
+ BasicBlock::reverse_iterator InstIt(Inst->getIterator()),
+ PrevInstIt(PrevInst->getIterator());
--PrevInstIt;
while (InstIt != PrevInstIt) {
if (PrevInstIt == PrevInst->getParent()->rend()) {
return -1;
}
-bool BoUpSLP::isConsecutiveAccess(Value *A, Value *B) {
+bool BoUpSLP::isConsecutiveAccess(Value *A, Value *B, const DataLayout &DL) {
Value *PtrA = getPointerOperand(A);
Value *PtrB = getPointerOperand(B);
unsigned ASA = getAddressSpaceOperand(A);
if (PtrA == PtrB || PtrA->getType() != PtrB->getType())
return false;
- unsigned PtrBitWidth = DL->getPointerSizeInBits(ASA);
+ unsigned PtrBitWidth = DL.getPointerSizeInBits(ASA);
Type *Ty = cast<PointerType>(PtrA->getType())->getElementType();
- APInt Size(PtrBitWidth, DL->getTypeStoreSize(Ty));
+ APInt Size(PtrBitWidth, DL.getTypeStoreSize(Ty));
APInt OffsetA(PtrBitWidth, 0), OffsetB(PtrBitWidth, 0);
- PtrA = PtrA->stripAndAccumulateInBoundsConstantOffsets(*DL, OffsetA);
- PtrB = PtrB->stripAndAccumulateInBoundsConstantOffsets(*DL, OffsetB);
+ PtrA = PtrA->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetA);
+ PtrB = PtrB->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetB);
APInt OffsetDelta = OffsetB - OffsetA;
return X == PtrSCEVB;
}
+// Reorder commutative operations in alternate shuffle if the resulting vectors
+// are consecutive loads. This would allow us to vectorize the tree.
+// If we have something like-
+// load a[0] - load b[0]
+// load b[1] + load a[1]
+// load a[2] - load b[2]
+// load a[3] + load b[3]
+// Reordering the second load b[1] load a[1] would allow us to vectorize this
+// code.
+void BoUpSLP::reorderAltShuffleOperands(ArrayRef<Value *> VL,
+ SmallVectorImpl<Value *> &Left,
+ SmallVectorImpl<Value *> &Right) {
+ const DataLayout &DL = F->getParent()->getDataLayout();
+
+ // Push left and right operands of binary operation into Left and Right
+ for (unsigned i = 0, e = VL.size(); i < e; ++i) {
+ Left.push_back(cast<Instruction>(VL[i])->getOperand(0));
+ Right.push_back(cast<Instruction>(VL[i])->getOperand(1));
+ }
+
+ // Reorder if we have a commutative operation and consecutive access
+ // are on either side of the alternate instructions.
+ for (unsigned j = 0; j < VL.size() - 1; ++j) {
+ if (LoadInst *L = dyn_cast<LoadInst>(Left[j])) {
+ if (LoadInst *L1 = dyn_cast<LoadInst>(Right[j + 1])) {
+ Instruction *VL1 = cast<Instruction>(VL[j]);
+ Instruction *VL2 = cast<Instruction>(VL[j + 1]);
+ if (isConsecutiveAccess(L, L1, DL) && VL1->isCommutative()) {
+ std::swap(Left[j], Right[j]);
+ continue;
+ } else if (isConsecutiveAccess(L, L1, DL) && VL2->isCommutative()) {
+ std::swap(Left[j + 1], Right[j + 1]);
+ continue;
+ }
+ // else unchanged
+ }
+ }
+ if (LoadInst *L = dyn_cast<LoadInst>(Right[j])) {
+ if (LoadInst *L1 = dyn_cast<LoadInst>(Left[j + 1])) {
+ Instruction *VL1 = cast<Instruction>(VL[j]);
+ Instruction *VL2 = cast<Instruction>(VL[j + 1]);
+ if (isConsecutiveAccess(L, L1, DL) && VL1->isCommutative()) {
+ std::swap(Left[j], Right[j]);
+ continue;
+ } else if (isConsecutiveAccess(L, L1, DL) && VL2->isCommutative()) {
+ std::swap(Left[j + 1], Right[j + 1]);
+ continue;
+ }
+ // else unchanged
+ }
+ }
+ }
+}
+
+
+// Return true if I should be commuted before adding it's left and right
+// operands to the arrays Left and Right.
+//
+// The vectorizer is trying to either have all elements one side being
+// instruction with the same opcode to enable further vectorization, or having
+// a splat to lower the vectorizing cost.
+static bool shouldReorderOperands(int i, Instruction &I,
+ SmallVectorImpl<Value *> &Left,
+ SmallVectorImpl<Value *> &Right) {
+ Value *VLeft = I.getOperand(0);
+ Value *VRight = I.getOperand(1);
+ Instruction *ILeft = dyn_cast<Instruction>(VLeft);
+ Instruction *IRight = dyn_cast<Instruction>(VRight);
+
+ // Sort two opcodes. In the code below we try to preserve the ability to use
+ // broadcast of values instead of individual inserts.
+ // vl1 = load
+ // vl2 = phi
+ // vr1 = load
+ // vr2 = vr2
+ // = vl1 x vr1
+ // = vl2 x vr2
+ // If we just sorted according to opcode we would leave the first line in
+ // tact but we would swap vl2 with vr2 because opcode(phi) > opcode(load).
+ // = vl1 x vr1
+ // = vr2 x vl2
+ // Because vr2 and vr1 are from the same load we loose the opportunity of a
+ // broadcast for the packed right side in the backend: we have [vr1, vl2]
+ // instead of [vr1, vr2=vr1].
+ if (ILeft && IRight) {
+ if (ILeft->getOpcode() > IRight->getOpcode() &&
+ Right[i - 1] != IRight) {
+ // Try not to destroy a broad cast for no apparent benefit.
+ return true;
+ } else if (ILeft->getOpcode() == IRight->getOpcode() &&
+ Right[i - 1] == ILeft) {
+ // Try preserve broadcasts.
+ return true;
+ } else if (ILeft->getOpcode() == IRight->getOpcode() &&
+ Left[i - 1] == IRight) {
+ // Try preserve broadcasts.
+ return true;
+ }
+ return false;
+ }
+ // One opcode, put the instruction on the right.
+ if (ILeft) {
+ return true;
+ }
+ return false;
+}
+
+void BoUpSLP::reorderInputsAccordingToOpcode(ArrayRef<Value *> VL,
+ SmallVectorImpl<Value *> &Left,
+ SmallVectorImpl<Value *> &Right) {
+
+ SmallVector<Value *, 16> OrigLeft, OrigRight;
+
+ if (VL.size()) {
+ // Peel the first iteration out of the loop since there's nothing
+ // interesting to do anyway and it simplifies the checks
+ auto VLeft = cast<Instruction>(VL[0])->getOperand(0);
+ auto VRight = cast<Instruction>(VL[0])->getOperand(1);
+ OrigLeft.push_back(VLeft);
+ OrigRight.push_back(VRight);
+ if (!isa<Instruction>(VRight) && isa<Instruction>(VLeft))
+ // Favor having instruction to the right. FIXME: why?
+ std::swap(VLeft, VRight);
+ Left.push_back(VLeft);
+ Right.push_back(VRight);
+ }
+
+ // Keep track if we have instructions with all the same opcode on one side.
+ bool AllSameOpcodeLeft = isa<Instruction>(Left[0]);
+ bool AllSameOpcodeRight = isa<Instruction>(Right[0]);
+
+ for (unsigned i = 1, e = VL.size(); i != e; ++i) {
+ Instruction *I = cast<Instruction>(VL[i]);
+
+ Value *VLeft = I->getOperand(0);
+ Value *VRight = I->getOperand(1);
+ OrigLeft.push_back(VLeft);
+ OrigRight.push_back(VRight);
+ Instruction *ILeft = dyn_cast<Instruction>(VLeft);
+ Instruction *IRight = dyn_cast<Instruction>(VRight);
+
+ // Check whether all operands on one side have the same opcode. In this case
+ // we want to preserve the original order and not make things worse by
+ // reordering.
+ if (AllSameOpcodeLeft && ILeft) {
+ if (Instruction *PLeft = dyn_cast<Instruction>(OrigLeft[i - 1])) {
+ if (PLeft->getOpcode() != ILeft->getOpcode())
+ AllSameOpcodeLeft = false;
+ } else
+ AllSameOpcodeLeft = false;
+ }
+ if (AllSameOpcodeRight && IRight) {
+ if (Instruction *PRight = dyn_cast<Instruction>(OrigRight[i - 1])) {
+ if (PRight->getOpcode() != IRight->getOpcode())
+ AllSameOpcodeRight = false;
+ } else
+ AllSameOpcodeRight = false;
+ }
+
+
+ // Commute to favor either a splat or maximizing having the same opcodes on
+ // one side.
+ if (shouldReorderOperands(i, *I, Left, Right)) {
+ Left.push_back(I->getOperand(1));
+ Right.push_back(I->getOperand(0));
+ } else {
+ Left.push_back(I->getOperand(0));
+ Right.push_back(I->getOperand(1));
+ }
+ }
+
+ bool LeftBroadcast = isSplat(Left);
+ bool RightBroadcast = isSplat(Right);
+
+ // If operands end up being broadcast return this operand order.
+ if (LeftBroadcast || RightBroadcast)
+ return;
+
+ // Don't reorder if the operands where good to begin.
+ if (AllSameOpcodeRight || AllSameOpcodeLeft) {
+ Left = OrigLeft;
+ Right = OrigRight;
+ }
+
+ const DataLayout &DL = F->getParent()->getDataLayout();
+
+ // Finally check if we can get longer vectorizable chain by reordering
+ // without breaking the good operand order detected above.
+ // E.g. If we have something like-
+ // load a[0] load b[0]
+ // load b[1] load a[1]
+ // load a[2] load b[2]
+ // load a[3] load b[3]
+ // Reordering the second load b[1] load a[1] would allow us to vectorize
+ // this code and we still retain AllSameOpcode property.
+ // FIXME: This load reordering might break AllSameOpcode in some rare cases
+ // such as-
+ // add a[0],c[0] load b[0]
+ // add a[1],c[2] load b[1]
+ // b[2] load b[2]
+ // add a[3],c[3] load b[3]
+ for (unsigned j = 0; j < VL.size() - 1; ++j) {
+ if (LoadInst *L = dyn_cast<LoadInst>(Left[j])) {
+ if (LoadInst *L1 = dyn_cast<LoadInst>(Right[j + 1])) {
+ if (isConsecutiveAccess(L, L1, DL)) {
+ std::swap(Left[j + 1], Right[j + 1]);
+ continue;
+ }
+ }
+ }
+ if (LoadInst *L = dyn_cast<LoadInst>(Right[j])) {
+ if (LoadInst *L1 = dyn_cast<LoadInst>(Left[j + 1])) {
+ if (isConsecutiveAccess(L, L1, DL)) {
+ std::swap(Left[j + 1], Right[j + 1]);
+ continue;
+ }
+ }
+ }
+ // else unchanged
+ }
+}
+
void BoUpSLP::setInsertPointAfterBundle(ArrayRef<Value *> VL) {
Instruction *VL0 = cast<Instruction>(VL[0]);
- BasicBlock::iterator NextInst = VL0;
+ BasicBlock::iterator NextInst(VL0);
++NextInst;
Builder.SetInsertPoint(VL0->getParent(), NextInst);
Builder.SetCurrentDebugLocation(VL0->getDebugLoc());
return Gather(E->Scalars, VecTy);
}
+ const DataLayout &DL = F->getParent()->getDataLayout();
unsigned Opcode = getSameOpcode(E->Scalars);
switch (Opcode) {
}
// Prepare the operand vector.
- for (unsigned j = 0; j < E->Scalars.size(); ++j)
- Operands.push_back(cast<PHINode>(E->Scalars[j])->
- getIncomingValueForBlock(IBB));
+ for (Value *V : E->Scalars)
+ Operands.push_back(cast<PHINode>(V)->getIncomingValueForBlock(IBB));
Builder.SetInsertPoint(IBB->getTerminator());
Builder.SetCurrentDebugLocation(PH->getDebugLoc());
case Instruction::FPTrunc:
case Instruction::BitCast: {
ValueList INVL;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i)
- INVL.push_back(cast<Instruction>(E->Scalars[i])->getOperand(0));
+ for (Value *V : E->Scalars)
+ INVL.push_back(cast<Instruction>(V)->getOperand(0));
setInsertPointAfterBundle(E->Scalars);
case Instruction::FCmp:
case Instruction::ICmp: {
ValueList LHSV, RHSV;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i) {
- LHSV.push_back(cast<Instruction>(E->Scalars[i])->getOperand(0));
- RHSV.push_back(cast<Instruction>(E->Scalars[i])->getOperand(1));
+ for (Value *V : E->Scalars) {
+ LHSV.push_back(cast<Instruction>(V)->getOperand(0));
+ RHSV.push_back(cast<Instruction>(V)->getOperand(1));
}
setInsertPointAfterBundle(E->Scalars);
if (Value *V = alreadyVectorized(E->Scalars))
return V;
- CmpInst::Predicate P0 = dyn_cast<CmpInst>(VL0)->getPredicate();
+ CmpInst::Predicate P0 = cast<CmpInst>(VL0)->getPredicate();
Value *V;
if (Opcode == Instruction::FCmp)
V = Builder.CreateFCmp(P0, L, R);
}
case Instruction::Select: {
ValueList TrueVec, FalseVec, CondVec;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i) {
- CondVec.push_back(cast<Instruction>(E->Scalars[i])->getOperand(0));
- TrueVec.push_back(cast<Instruction>(E->Scalars[i])->getOperand(1));
- FalseVec.push_back(cast<Instruction>(E->Scalars[i])->getOperand(2));
+ for (Value *V : E->Scalars) {
+ CondVec.push_back(cast<Instruction>(V)->getOperand(0));
+ TrueVec.push_back(cast<Instruction>(V)->getOperand(1));
+ FalseVec.push_back(cast<Instruction>(V)->getOperand(2));
}
setInsertPointAfterBundle(E->Scalars);
if (isa<BinaryOperator>(VL0) && VL0->isCommutative())
reorderInputsAccordingToOpcode(E->Scalars, LHSVL, RHSVL);
else
- for (int i = 0, e = E->Scalars.size(); i < e; ++i) {
- LHSVL.push_back(cast<Instruction>(E->Scalars[i])->getOperand(0));
- RHSVL.push_back(cast<Instruction>(E->Scalars[i])->getOperand(1));
+ for (Value *V : E->Scalars) {
+ LHSVL.push_back(cast<Instruction>(V)->getOperand(0));
+ RHSVL.push_back(cast<Instruction>(V)->getOperand(1));
}
setInsertPointAfterBundle(E->Scalars);
unsigned Alignment = LI->getAlignment();
LI = Builder.CreateLoad(VecPtr);
- if (!Alignment)
- Alignment = DL->getABITypeAlignment(ScalarLoadTy);
+ if (!Alignment) {
+ Alignment = DL.getABITypeAlignment(ScalarLoadTy);
+ }
LI->setAlignment(Alignment);
E->VectorizedValue = LI;
++NumVectorInstructions;
unsigned AS = SI->getPointerAddressSpace();
ValueList ValueOp;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i)
- ValueOp.push_back(cast<StoreInst>(E->Scalars[i])->getValueOperand());
+ for (Value *V : E->Scalars)
+ ValueOp.push_back(cast<StoreInst>(V)->getValueOperand());
setInsertPointAfterBundle(E->Scalars);
ExternalUses.push_back(
ExternalUser(SI->getPointerOperand(), cast<User>(VecPtr), 0));
- if (!Alignment)
- Alignment = DL->getABITypeAlignment(SI->getValueOperand()->getType());
+ if (!Alignment) {
+ Alignment = DL.getABITypeAlignment(SI->getValueOperand()->getType());
+ }
S->setAlignment(Alignment);
E->VectorizedValue = S;
++NumVectorInstructions;
setInsertPointAfterBundle(E->Scalars);
ValueList Op0VL;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i)
- Op0VL.push_back(cast<GetElementPtrInst>(E->Scalars[i])->getOperand(0));
+ for (Value *V : E->Scalars)
+ Op0VL.push_back(cast<GetElementPtrInst>(V)->getOperand(0));
Value *Op0 = vectorizeTree(Op0VL);
for (int j = 1, e = cast<GetElementPtrInst>(VL0)->getNumOperands(); j < e;
++j) {
ValueList OpVL;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i)
- OpVL.push_back(cast<GetElementPtrInst>(E->Scalars[i])->getOperand(j));
+ for (Value *V : E->Scalars)
+ OpVL.push_back(cast<GetElementPtrInst>(V)->getOperand(j));
Value *OpVec = vectorizeTree(OpVL);
OpVecs.push_back(OpVec);
}
- Value *V = Builder.CreateGEP(Op0, OpVecs);
+ Value *V = Builder.CreateGEP(
+ cast<GetElementPtrInst>(VL0)->getSourceElementType(), Op0, OpVecs);
E->VectorizedValue = V;
++NumVectorInstructions;
Intrinsic::ID IID = Intrinsic::not_intrinsic;
Value *ScalarArg = nullptr;
if (CI && (FI = CI->getCalledFunction())) {
- IID = (Intrinsic::ID) FI->getIntrinsicID();
+ IID = FI->getIntrinsicID();
}
std::vector<Value *> OpVecs;
for (int j = 0, e = CI->getNumArgOperands(); j < e; ++j) {
OpVecs.push_back(CEI->getArgOperand(j));
continue;
}
- for (int i = 0, e = E->Scalars.size(); i < e; ++i) {
- CallInst *CEI = cast<CallInst>(E->Scalars[i]);
+ for (Value *V : E->Scalars) {
+ CallInst *CEI = cast<CallInst>(V);
OpVL.push_back(CEI->getArgOperand(j));
}
}
case Instruction::ShuffleVector: {
ValueList LHSVL, RHSVL;
- for (int i = 0, e = E->Scalars.size(); i < e; ++i) {
- LHSVL.push_back(cast<Instruction>(E->Scalars[i])->getOperand(0));
- RHSVL.push_back(cast<Instruction>(E->Scalars[i])->getOperand(1));
- }
+ assert(isa<BinaryOperator>(VL0) && "Invalid Shuffle Vector Operand");
+ reorderAltShuffleOperands(E->Scalars, LHSVL, RHSVL);
setInsertPointAfterBundle(E->Scalars);
Value *LHS = vectorizeTree(LHSVL);
scheduleBlock(BSIter.second.get());
}
- Builder.SetInsertPoint(F->getEntryBlock().begin());
+ Builder.SetInsertPoint(&F->getEntryBlock().front());
vectorizeTree(&VectorizableTree[0]);
DEBUG(dbgs() << "SLP: Extracting " << ExternalUses.size() << " values .\n");
User->replaceUsesOfWith(Scalar, Ex);
}
} else {
- Builder.SetInsertPoint(F->getEntryBlock().begin());
+ Builder.SetInsertPoint(&F->getEntryBlock().front());
Value *Ex = Builder.CreateExtractElement(Vec, Lane);
CSEBlocks.insert(&F->getEntryBlock());
User->replaceUsesOfWith(Scalar, Ex);
BasicBlock *BB = (*I)->getBlock();
// For all instructions in blocks containing gather sequences:
for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e;) {
- Instruction *In = it++;
+ Instruction *In = &*it++;
if (!isa<InsertElementInst>(In) && !isa<ExtractElementInst>(In))
continue;
ScheduleData *Bundle = nullptr;
bool ReSchedule = false;
DEBUG(dbgs() << "SLP: bundle: " << *VL[0] << "\n");
+
+ // Make sure that the scheduling region contains all
+ // instructions of the bundle.
+ for (Value *V : VL) {
+ if (!extendSchedulingRegion(V))
+ return false;
+ }
+
for (Value *V : VL) {
- extendSchedulingRegion(V);
ScheduleData *BundleMember = getScheduleData(V);
assert(BundleMember &&
"no ScheduleData for bundle member (maybe not in same basic block)");
schedule(pickedSD, ReadyInsts);
}
}
- return Bundle->isReady();
+ if (!Bundle->isReady()) {
+ cancelScheduling(VL);
+ return false;
+ }
+ return true;
}
void BoUpSLP::BlockScheduling::cancelScheduling(ArrayRef<Value *> VL) {
}
}
-void BoUpSLP::BlockScheduling::extendSchedulingRegion(Value *V) {
+bool BoUpSLP::BlockScheduling::extendSchedulingRegion(Value *V) {
if (getScheduleData(V))
- return;
+ return true;
Instruction *I = dyn_cast<Instruction>(V);
assert(I && "bundle member must be an instruction");
assert(!isa<PHINode>(I) && "phi nodes don't need to be scheduled");
ScheduleEnd = I->getNextNode();
assert(ScheduleEnd && "tried to vectorize a TerminatorInst?");
DEBUG(dbgs() << "SLP: initialize schedule region to " << *I << "\n");
- return;
+ return true;
}
// Search up and down at the same time, because we don't know if the new
// instruction is above or below the existing scheduling region.
- BasicBlock::reverse_iterator UpIter(ScheduleStart);
+ BasicBlock::reverse_iterator UpIter(ScheduleStart->getIterator());
BasicBlock::reverse_iterator UpperEnd = BB->rend();
BasicBlock::iterator DownIter(ScheduleEnd);
BasicBlock::iterator LowerEnd = BB->end();
for (;;) {
+ if (++ScheduleRegionSize > ScheduleRegionSizeLimit) {
+ DEBUG(dbgs() << "SLP: exceeded schedule region size limit\n");
+ return false;
+ }
+
if (UpIter != UpperEnd) {
if (&*UpIter == I) {
initScheduleData(I, ScheduleStart, nullptr, FirstLoadStoreInRegion);
ScheduleStart = I;
DEBUG(dbgs() << "SLP: extend schedule region start to " << *I << "\n");
- return;
+ return true;
}
UpIter++;
}
ScheduleEnd = I->getNextNode();
assert(ScheduleEnd && "tried to vectorize a TerminatorInst?");
DEBUG(dbgs() << "SLP: extend schedule region end to " << *I << "\n");
- return;
+ return true;
}
DownIter++;
}
assert((UpIter != UpperEnd || DownIter != LowerEnd) &&
"instruction not found in block");
}
+ return true;
}
void BoUpSLP::BlockScheduling::initScheduleData(Instruction *FromI,
}
} else {
// I'm not sure if this can ever happen. But we need to be safe.
- // This lets the instruction/bundle never be scheduled and eventally
- // disable vectorization.
+ // This lets the instruction/bundle never be scheduled and
+ // eventually disable vectorization.
BundleMember->Dependencies++;
BundleMember->incrementUnscheduledDeps(1);
}
ScheduleData *DepDest = BundleMember->NextLoadStore;
if (DepDest) {
Instruction *SrcInst = BundleMember->Inst;
- AliasAnalysis::Location SrcLoc = getLocation(SrcInst, SLP->AA);
+ MemoryLocation SrcLoc = getLocation(SrcInst, SLP->AA);
bool SrcMayWrite = BundleMember->Inst->mayWriteToMemory();
+ unsigned numAliased = 0;
+ unsigned DistToSrc = 1;
while (DepDest) {
assert(isInSchedulingRegion(DepDest));
- if (SrcMayWrite || DepDest->Inst->mayWriteToMemory()) {
- if (SLP->isAliased(SrcLoc, SrcInst, DepDest->Inst)) {
- DepDest->MemoryDependencies.push_back(BundleMember);
- BundleMember->Dependencies++;
- ScheduleData *DestBundle = DepDest->FirstInBundle;
- if (!DestBundle->IsScheduled) {
- BundleMember->incrementUnscheduledDeps(1);
- }
- if (!DestBundle->hasValidDependencies()) {
- WorkList.push_back(DestBundle);
- }
+
+ // We have two limits to reduce the complexity:
+ // 1) AliasedCheckLimit: It's a small limit to reduce calls to
+ // SLP->isAliased (which is the expensive part in this loop).
+ // 2) MaxMemDepDistance: It's for very large blocks and it aborts
+ // the whole loop (even if the loop is fast, it's quadratic).
+ // It's important for the loop break condition (see below) to
+ // check this limit even between two read-only instructions.
+ if (DistToSrc >= MaxMemDepDistance ||
+ ((SrcMayWrite || DepDest->Inst->mayWriteToMemory()) &&
+ (numAliased >= AliasedCheckLimit ||
+ SLP->isAliased(SrcLoc, SrcInst, DepDest->Inst)))) {
+
+ // We increment the counter only if the locations are aliased
+ // (instead of counting all alias checks). This gives a better
+ // balance between reduced runtime and accurate dependencies.
+ numAliased++;
+
+ DepDest->MemoryDependencies.push_back(BundleMember);
+ BundleMember->Dependencies++;
+ ScheduleData *DestBundle = DepDest->FirstInBundle;
+ if (!DestBundle->IsScheduled) {
+ BundleMember->incrementUnscheduledDeps(1);
+ }
+ if (!DestBundle->hasValidDependencies()) {
+ WorkList.push_back(DestBundle);
}
}
DepDest = DepDest->NextLoadStore;
+
+ // Example, explaining the loop break condition: Let's assume our
+ // starting instruction is i0 and MaxMemDepDistance = 3.
+ //
+ // +--------v--v--v
+ // i0,i1,i2,i3,i4,i5,i6,i7,i8
+ // +--------^--^--^
+ //
+ // MaxMemDepDistance let us stop alias-checking at i3 and we add
+ // dependencies from i0 to i3,i4,.. (even if they are not aliased).
+ // Previously we already added dependencies from i3 to i6,i7,i8
+ // (because of MaxMemDepDistance). As we added a dependency from
+ // i0 to i3, we have transitive dependencies from i0 to i6,i7,i8
+ // and we can abort this loop at i6.
+ if (DistToSrc >= 2 * MaxMemDepDistance)
+ break;
+ DistToSrc++;
}
}
}
};
std::set<ScheduleData *, ScheduleDataCompare> ReadyInsts;
- // Ensure that all depencency data is updated and fill the ready-list with
+ // Ensure that all dependency data is updated and fill the ready-list with
// initial instructions.
int Idx = 0;
int NumToSchedule = 0;
Instruction *pickedInst = BundleMember->Inst;
if (LastScheduledInst->getNextNode() != pickedInst) {
BS->BB->getInstList().remove(pickedInst);
- BS->BB->getInstList().insert(LastScheduledInst, pickedInst);
+ BS->BB->getInstList().insert(LastScheduledInst->getIterator(),
+ pickedInst);
}
LastScheduledInst = pickedInst;
BundleMember = BundleMember->NextInBundle;
}
ScalarEvolution *SE;
- const DataLayout *DL;
TargetTransformInfo *TTI;
TargetLibraryInfo *TLI;
AliasAnalysis *AA;
if (skipOptnoneFunction(F))
return false;
- SE = &getAnalysis<ScalarEvolution>();
- DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- DL = DLP ? &DLP->getDataLayout() : nullptr;
- TTI = &getAnalysis<TargetTransformInfo>();
+ SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+ TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
TLI = TLIP ? &TLIP->getTLI() : nullptr;
- AA = &getAnalysis<AliasAnalysis>();
- LI = &getAnalysis<LoopInfo>();
+ AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
+ LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
if (!TTI->getNumberOfRegisters(true))
return false;
- // Must have DataLayout. We can't require it because some tests run w/o
- // triple.
- if (!DL)
- return false;
+ // Use the vector register size specified by the target unless overridden
+ // by a command-line option.
+ // TODO: It would be better to limit the vectorization factor based on
+ // data type rather than just register size. For example, x86 AVX has
+ // 256-bit registers, but it does not support integer operations
+ // at that width (that requires AVX2).
+ if (MaxVectorRegSizeOption.getNumOccurrences())
+ MaxVecRegSize = MaxVectorRegSizeOption;
+ else
+ MaxVecRegSize = TTI->getRegisterBitWidth(true);
// Don't vectorize when the attribute NoImplicitFloat is used.
if (F.hasFnAttribute(Attribute::NoImplicitFloat))
// Use the bottom up slp vectorizer to construct chains that start with
// store instructions.
- BoUpSLP R(&F, SE, DL, TTI, TLI, AA, LI, DT, AC);
+ BoUpSLP R(&F, SE, TTI, TLI, AA, LI, DT, AC);
// A general note: the vectorizer must use BoUpSLP::eraseInstruction() to
// delete instructions.
// Scan the blocks in the function in post order.
- for (po_iterator<BasicBlock*> it = po_begin(&F.getEntryBlock()),
- e = po_end(&F.getEntryBlock()); it != e; ++it) {
- BasicBlock *BB = *it;
+ for (auto BB : post_order(&F.getEntryBlock())) {
// Vectorize trees that end at stores.
if (unsigned count = collectStores(BB, R)) {
(void)count;
void getAnalysisUsage(AnalysisUsage &AU) const override {
FunctionPass::getAnalysisUsage(AU);
AU.addRequired<AssumptionCacheTracker>();
- AU.addRequired<ScalarEvolution>();
- AU.addRequired<AliasAnalysis>();
- AU.addRequired<TargetTransformInfo>();
- AU.addRequired<LoopInfo>();
+ AU.addRequired<ScalarEvolutionWrapperPass>();
+ AU.addRequired<AAResultsWrapperPass>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ AU.addRequired<LoopInfoWrapperPass>();
AU.addRequired<DominatorTreeWrapperPass>();
- AU.addPreserved<LoopInfo>();
+ AU.addPreserved<LoopInfoWrapperPass>();
AU.addPreserved<DominatorTreeWrapperPass>();
AU.setPreservesCFG();
}
bool vectorizeChainsInBlock(BasicBlock *BB, BoUpSLP &R);
bool vectorizeStoreChain(ArrayRef<Value *> Chain, int CostThreshold,
- BoUpSLP &R);
+ BoUpSLP &R, unsigned VecRegSize);
bool vectorizeStores(ArrayRef<StoreInst *> Stores, int costThreshold,
BoUpSLP &R);
private:
StoreListMap StoreRefs;
+ unsigned MaxVecRegSize; // This is set by TTI or overridden by cl::opt.
};
/// \brief Check that the Values in the slice in VL array are still existent in
/// the WeakVH array.
/// Vectorization of part of the VL array may cause later values in the VL array
/// to become invalid. We track when this has happened in the WeakVH array.
-static bool hasValueBeenRAUWed(ArrayRef<Value *> &VL,
- SmallVectorImpl<WeakVH> &VH,
- unsigned SliceBegin,
- unsigned SliceSize) {
- for (unsigned i = SliceBegin; i < SliceBegin + SliceSize; ++i)
- if (VH[i] != VL[i])
- return true;
-
- return false;
+static bool hasValueBeenRAUWed(ArrayRef<Value *> VL, ArrayRef<WeakVH> VH,
+ unsigned SliceBegin, unsigned SliceSize) {
+ VL = VL.slice(SliceBegin, SliceSize);
+ VH = VH.slice(SliceBegin, SliceSize);
+ return !std::equal(VL.begin(), VL.end(), VH.begin());
}
bool SLPVectorizer::vectorizeStoreChain(ArrayRef<Value *> Chain,
- int CostThreshold, BoUpSLP &R) {
+ int CostThreshold, BoUpSLP &R,
+ unsigned VecRegSize) {
unsigned ChainLen = Chain.size();
DEBUG(dbgs() << "SLP: Analyzing a store chain of length " << ChainLen
<< "\n");
Type *StoreTy = cast<StoreInst>(Chain[0])->getValueOperand()->getType();
- unsigned Sz = DL->getTypeSizeInBits(StoreTy);
- unsigned VF = MinVecRegSize / Sz;
+ auto &DL = cast<StoreInst>(Chain[0])->getModule()->getDataLayout();
+ unsigned Sz = DL.getTypeSizeInBits(StoreTy);
+ unsigned VF = VecRegSize / Sz;
if (!isPowerOf2_32(Sz) || VF < 2)
return false;
bool SLPVectorizer::vectorizeStores(ArrayRef<StoreInst *> Stores,
int costThreshold, BoUpSLP &R) {
- SetVector<Value *> Heads, Tails;
- SmallDenseMap<Value *, Value *> ConsecutiveChain;
+ SetVector<StoreInst *> Heads, Tails;
+ SmallDenseMap<StoreInst *, StoreInst *> ConsecutiveChain;
// We may run into multiple chains that merge into a single chain. We mark the
// stores that we vectorized so that we don't visit the same store twice.
// Do a quadratic search on all of the given stores and find
// all of the pairs of stores that follow each other.
+ SmallVector<unsigned, 16> IndexQueue;
for (unsigned i = 0, e = Stores.size(); i < e; ++i) {
- for (unsigned j = 0; j < e; ++j) {
- if (i == j)
- continue;
-
- if (R.isConsecutiveAccess(Stores[i], Stores[j])) {
- Tails.insert(Stores[j]);
+ const DataLayout &DL = Stores[i]->getModule()->getDataLayout();
+ IndexQueue.clear();
+ // If a store has multiple consecutive store candidates, search Stores
+ // array according to the sequence: from i+1 to e, then from i-1 to 0.
+ // This is because usually pairing with immediate succeeding or preceding
+ // candidate create the best chance to find slp vectorization opportunity.
+ unsigned j = 0;
+ for (j = i + 1; j < e; ++j)
+ IndexQueue.push_back(j);
+ for (j = i; j > 0; --j)
+ IndexQueue.push_back(j - 1);
+
+ for (auto &k : IndexQueue) {
+ if (R.isConsecutiveAccess(Stores[i], Stores[k], DL)) {
+ Tails.insert(Stores[k]);
Heads.insert(Stores[i]);
- ConsecutiveChain[Stores[i]] = Stores[j];
+ ConsecutiveChain[Stores[i]] = Stores[k];
+ break;
}
}
}
// For stores that start but don't end a link in the chain:
- for (SetVector<Value *>::iterator it = Heads.begin(), e = Heads.end();
+ for (SetVector<StoreInst *>::iterator it = Heads.begin(), e = Heads.end();
it != e; ++it) {
if (Tails.count(*it))
continue;
// We found a store instr that starts a chain. Now follow the chain and try
// to vectorize it.
BoUpSLP::ValueList Operands;
- Value *I = *it;
+ StoreInst *I = *it;
// Collect the chain into a list.
while (Tails.count(I) || Heads.count(I)) {
if (VectorizedStores.count(I))
I = ConsecutiveChain[I];
}
- bool Vectorized = vectorizeStoreChain(Operands, costThreshold, R);
-
- // Mark the vectorized stores so that we don't vectorize them again.
- if (Vectorized)
- VectorizedStores.insert(Operands.begin(), Operands.end());
- Changed |= Vectorized;
+ // FIXME: Is division-by-2 the correct step? Should we assert that the
+ // register size is a power-of-2?
+ for (unsigned Size = MaxVecRegSize; Size >= MinVecRegSize; Size /= 2) {
+ if (vectorizeStoreChain(Operands, costThreshold, R, Size)) {
+ // Mark the vectorized stores so that we don't vectorize them again.
+ VectorizedStores.insert(Operands.begin(), Operands.end());
+ Changed = true;
+ break;
+ }
+ }
}
return Changed;
unsigned SLPVectorizer::collectStores(BasicBlock *BB, BoUpSLP &R) {
unsigned count = 0;
StoreRefs.clear();
- for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) {
- StoreInst *SI = dyn_cast<StoreInst>(it);
+ const DataLayout &DL = BB->getModule()->getDataLayout();
+ for (Instruction &I : *BB) {
+ StoreInst *SI = dyn_cast<StoreInst>(&I);
if (!SI)
continue;
// Check that the pointer points to scalars.
Type *Ty = SI->getValueOperand()->getType();
- if (Ty->isAggregateType() || Ty->isVectorTy())
+ if (!isValidElementType(Ty))
continue;
// Find the base pointer.
return false;
unsigned Opcode0 = I0->getOpcode();
+ const DataLayout &DL = I0->getModule()->getDataLayout();
Type *Ty0 = I0->getType();
- unsigned Sz = DL->getTypeSizeInBits(Ty0);
+ unsigned Sz = DL.getTypeSizeInBits(Ty0);
+ // FIXME: Register size should be a parameter to this function, so we can
+ // try different vectorization factors.
unsigned VF = MinVecRegSize / Sz;
- for (int i = 0, e = VL.size(); i < e; ++i) {
- Type *Ty = VL[i]->getType();
- if (Ty->isAggregateType() || Ty->isVectorTy())
+ for (Value *V : VL) {
+ Type *Ty = V->getType();
+ if (!isValidElementType(Ty))
return false;
- Instruction *Inst = dyn_cast<Instruction>(VL[i]);
+ Instruction *Inst = dyn_cast<Instruction>(V);
if (!Inst || Inst->getOpcode() != Opcode0)
return false;
}
unsigned VecIdx = 0;
for (auto &V : BuildVectorSlice) {
IRBuilder<true, NoFolder> Builder(
- ++BasicBlock::iterator(InsertAfter));
+ InsertAfter->getParent(), ++BasicBlock::iterator(InsertAfter));
InsertElementInst *IE = cast<InsertElementInst>(V);
Instruction *Extract = cast<Instruction>(Builder.CreateExtractElement(
VectorizedRoot, Builder.getInt32(VecIdx++)));
ReducedValueOpcode(0), ReduxWidth(0), IsPairwiseReduction(false) {}
/// \brief Try to find a reduction tree.
- bool matchAssociativeReduction(PHINode *Phi, BinaryOperator *B,
- const DataLayout *DL) {
+ bool matchAssociativeReduction(PHINode *Phi, BinaryOperator *B) {
assert((!Phi ||
std::find(Phi->op_begin(), Phi->op_end(), B) != Phi->op_end()) &&
"Thi phi needs to use the binary operator");
return false;
Type *Ty = B->getType();
- if (Ty->isVectorTy())
+ if (!isValidElementType(Ty))
return false;
+ const DataLayout &DL = B->getModule()->getDataLayout();
ReductionOpcode = B->getOpcode();
ReducedValueOpcode = 0;
- ReduxWidth = MinVecRegSize / DL->getTypeSizeInBits(Ty);
+ // FIXME: Register size should be a parameter to this function, so we can
+ // try different vectorization factors.
+ ReduxWidth = MinVecRegSize / DL.getTypeSizeInBits(Ty);
ReductionRoot = B;
ReductionPHI = Phi;
private:
- /// \brief Calcuate the cost of a reduction.
+ /// \brief Calculate the cost of a reduction.
int getReductionCost(TargetTransformInfo *TTI, Value *FirstReducedVal) {
Type *ScalarTy = FirstReducedVal->getType();
Type *VecTy = VectorType::get(ScalarTy, ReduxWidth);
for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; it++) {
// We may go through BB multiple times so skip the one we have checked.
- if (!VisitedInstrs.insert(it).second)
+ if (!VisitedInstrs.insert(&*it).second)
continue;
if (isa<DbgInfoIntrinsic>(it))
// Try to match and vectorize a horizontal reduction.
HorizontalReduction HorRdx;
- if (ShouldVectorizeHor &&
- HorRdx.matchAssociativeReduction(P, BI, DL) &&
+ if (ShouldVectorizeHor && HorRdx.matchAssociativeReduction(P, BI) &&
HorRdx.tryToReduce(R, TTI)) {
Changed = true;
it = BB->begin();
if (BinaryOperator *BinOp =
dyn_cast<BinaryOperator>(SI->getValueOperand())) {
HorizontalReduction HorRdx;
- if (((HorRdx.matchAssociativeReduction(nullptr, BinOp, DL) &&
+ if (((HorRdx.matchAssociativeReduction(nullptr, BinOp) &&
HorRdx.tryToReduce(R, TTI)) ||
tryToVectorize(BinOp, R))) {
Changed = true;
// and the iterator may become invalid value.
it = BB->begin();
e = BB->end();
+ break;
}
}
}
<< it->second.size() << ".\n");
// Process the stores in chunks of 16.
+ // TODO: The limit of 16 inhibits greater vectorization factors.
+ // For example, AVX2 supports v32i8. Increasing this limit, however,
+ // may cause a significant compile-time increase.
for (unsigned CI = 0, CE = it->second.size(); CI < CE; CI+=16) {
unsigned Len = std::min<unsigned>(CE - CI, 16);
Changed |= vectorizeStores(makeArrayRef(&it->second[CI], Len),
char SLPVectorizer::ID = 0;
static const char lv_name[] = "SLP Vectorizer";
INITIALIZE_PASS_BEGIN(SLPVectorizer, SV_NAME, lv_name, false, false)
-INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
-INITIALIZE_AG_DEPENDENCY(TargetTransformInfo)
+INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_END(SLPVectorizer, SV_NAME, lv_name, false, false)
projects / oota-llvm.git / blobdiff