[llvm] 99203f2 - [Analysis]Add getPointersDiff function to improve compile time.
Alexey Bataev via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 23 14:26:30 PDT 2021
Author: Alexey Bataev
Date: 2021-03-23T14:25:36-07:00
New Revision: 99203f2004d031f2ef22f01e3c569d2775de1836
URL: https://github.com/llvm/llvm-project/commit/99203f2004d031f2ef22f01e3c569d2775de1836
DIFF: https://github.com/llvm/llvm-project/commit/99203f2004d031f2ef22f01e3c569d2775de1836.diff
LOG: [Analysis]Add getPointersDiff function to improve compile time.
Added getPointersDiff function to LoopAccessAnalysis and used it instead
direct calculatoin of the distance between pointers and/or
isConsecutiveAccess function in SLP vectorizer to improve compile time
and detection of stores consecutive chains.
Part of D57059
Differential Revision: https://reviews.llvm.org/D98967
Added:
Modified:
llvm/include/llvm/Analysis/LoopAccessAnalysis.h
llvm/lib/Analysis/LoopAccessAnalysis.cpp
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Analysis/LoopAccessAnalysis.h b/llvm/include/llvm/Analysis/LoopAccessAnalysis.h
index 13fbe884eddf..39acfd5bbbee 100644
--- a/llvm/include/llvm/Analysis/LoopAccessAnalysis.h
+++ b/llvm/include/llvm/Analysis/LoopAccessAnalysis.h
@@ -679,6 +679,15 @@ int64_t getPtrStride(PredicatedScalarEvolution &PSE, Value *Ptr, const Loop *Lp,
const ValueToValueMap &StridesMap = ValueToValueMap(),
bool Assume = false, bool ShouldCheckWrap = true);
+/// Returns the distance between the pointers \p PtrA and \p PtrB iff they are
+/// compatible and it is possible to calculate the distance between them. This
+/// is a simple API that does not depend on the analysis pass.
+/// \param StrictCheck Ensure that the calculated distance matches the
+/// type-based one after all the bitcasts removal in the provided pointers.
+Optional<int> getPointersDiff(Value *PtrA, Value *PtrB, const DataLayout &DL,
+ ScalarEvolution &SE, bool StrictCheck = false,
+ bool CheckType = true);
+
/// Attempt to sort the pointers in \p VL and return the sorted indices
/// in \p SortedIndices, if reordering is required.
///
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index e632fe25c24c..997d4474a448 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1124,139 +1124,123 @@ int64_t llvm::getPtrStride(PredicatedScalarEvolution &PSE, Value *Ptr,
return Stride;
}
+Optional<int> llvm::getPointersDiff(Value *PtrA, Value *PtrB,
+ const DataLayout &DL, ScalarEvolution &SE,
+ bool StrictCheck, bool CheckType) {
+ assert(PtrA && PtrB && "Expected non-nullptr pointers.");
+ // Make sure that A and B are
diff erent pointers.
+ if (PtrA == PtrB)
+ return 0;
+
+ // Make sure that PtrA and PtrB have the same type if required
+ if (CheckType && PtrA->getType() != PtrB->getType())
+ return None;
+
+ unsigned ASA = PtrA->getType()->getPointerAddressSpace();
+ unsigned ASB = PtrB->getType()->getPointerAddressSpace();
+
+ // Check that the address spaces match.
+ if (ASA != ASB)
+ return None;
+ unsigned IdxWidth = DL.getIndexSizeInBits(ASA);
+
+ APInt OffsetA(IdxWidth, 0), OffsetB(IdxWidth, 0);
+ Value *PtrA1 = PtrA->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetA);
+ Value *PtrB1 = PtrB->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetB);
+
+ int Val;
+ if (PtrA1 == PtrB1) {
+ // Retrieve the address space again as pointer stripping now tracks through
+ // `addrspacecast`.
+ ASA = cast<PointerType>(PtrA1->getType())->getAddressSpace();
+ ASB = cast<PointerType>(PtrB1->getType())->getAddressSpace();
+ // Check that the address spaces match and that the pointers are valid.
+ if (ASA != ASB)
+ return None;
+
+ IdxWidth = DL.getIndexSizeInBits(ASA);
+ OffsetA = OffsetA.sextOrTrunc(IdxWidth);
+ OffsetB = OffsetB.sextOrTrunc(IdxWidth);
+
+ OffsetB -= OffsetA;
+ Val = OffsetB.getSExtValue();
+ } else {
+ // Otherwise compute the distance with SCEV between the base pointers.
+ const SCEV *PtrSCEVA = SE.getSCEV(PtrA);
+ const SCEV *PtrSCEVB = SE.getSCEV(PtrB);
+ const auto *Diff =
+ dyn_cast<SCEVConstant>(SE.getMinusSCEV(PtrSCEVB, PtrSCEVA));
+ if (!Diff)
+ return None;
+ Val = Diff->getAPInt().getSExtValue();
+ }
+ Type *Ty = cast<PointerType>(PtrA->getType())->getElementType();
+ int Size = DL.getTypeStoreSize(Ty);
+ int Dist = Val / Size;
+
+ // Ensure that the calculated distance matches the type-based one after all
+ // the bitcasts removal in the provided pointers.
+ if (!StrictCheck || Dist * Size == Val)
+ return Dist;
+ return None;
+}
+
bool llvm::sortPtrAccesses(ArrayRef<Value *> VL, const DataLayout &DL,
ScalarEvolution &SE,
SmallVectorImpl<unsigned> &SortedIndices) {
assert(llvm::all_of(
VL, [](const Value *V) { return V->getType()->isPointerTy(); }) &&
"Expected list of pointer operands.");
- SmallVector<std::pair<int64_t, Value *>, 4> OffValPairs;
- OffValPairs.reserve(VL.size());
-
// Walk over the pointers, and map each of them to an offset relative to
// first pointer in the array.
Value *Ptr0 = VL[0];
- const SCEV *Scev0 = SE.getSCEV(Ptr0);
- Value *Obj0 = getUnderlyingObject(Ptr0);
-
- llvm::SmallSet<int64_t, 4> Offsets;
- for (auto *Ptr : VL) {
- // TODO: Outline this code as a special, more time consuming, version of
- // computeConstantDifference() function.
- if (Ptr->getType()->getPointerAddressSpace() !=
- Ptr0->getType()->getPointerAddressSpace())
- return false;
- // If a pointer refers to a
diff erent underlying object, bail - the
- // pointers are by definition incomparable.
- Value *CurrObj = getUnderlyingObject(Ptr);
- if (CurrObj != Obj0)
- return false;
- const SCEV *Scev = SE.getSCEV(Ptr);
- const auto *Diff = dyn_cast<SCEVConstant>(SE.getMinusSCEV(Scev, Scev0));
- // The pointers may not have a constant offset from each other, or SCEV
- // may just not be smart enough to figure out they do. Regardless,
- // there's nothing we can do.
+ using DistOrdPair = std::pair<int64_t, int>;
+ auto Compare = [](const DistOrdPair &L, const DistOrdPair &R) {
+ return L.first < R.first;
+ };
+ std::set<DistOrdPair, decltype(Compare)> Offsets(Compare);
+ Offsets.emplace(0, 0);
+ int Cnt = 1;
+ bool IsConsecutive = true;
+ for (auto *Ptr : VL.drop_front()) {
+ Optional<int> Diff = getPointersDiff(Ptr0, Ptr, DL, SE);
if (!Diff)
return false;
// Check if the pointer with the same offset is found.
- int64_t Offset = Diff->getAPInt().getSExtValue();
- if (!Offsets.insert(Offset).second)
+ int64_t Offset = *Diff;
+ auto Res = Offsets.emplace(Offset, Cnt);
+ if (!Res.second)
return false;
- OffValPairs.emplace_back(Offset, Ptr);
+ // Consecutive order if the inserted element is the last one.
+ IsConsecutive = IsConsecutive && std::next(Res.first) == Offsets.end();
+ ++Cnt;
}
SortedIndices.clear();
- SortedIndices.resize(VL.size());
- std::iota(SortedIndices.begin(), SortedIndices.end(), 0);
-
- // Sort the memory accesses and keep the order of their uses in UseOrder.
- llvm::stable_sort(SortedIndices, [&](unsigned Left, unsigned Right) {
- return OffValPairs[Left].first < OffValPairs[Right].first;
- });
-
- // Check if the order is consecutive already.
- if (llvm::all_of(SortedIndices, [&SortedIndices](const unsigned I) {
- return I == SortedIndices[I];
- }))
- SortedIndices.clear();
-
+ if (!IsConsecutive) {
+ // Fill SortedIndices array only if it is non-consecutive.
+ SortedIndices.resize(VL.size());
+ Cnt = 0;
+ for (const std::pair<int64_t, int> &Pair : Offsets) {
+ IsConsecutive = IsConsecutive && Cnt == Pair.second;
+ SortedIndices[Cnt] = Pair.second;
+ ++Cnt;
+ }
+ }
return true;
}
-/// Take the address space operand from the Load/Store instruction.
-/// Returns -1 if this is not a valid Load/Store instruction.
-static unsigned getAddressSpaceOperand(Value *I) {
- if (LoadInst *L = dyn_cast<LoadInst>(I))
- return L->getPointerAddressSpace();
- if (StoreInst *S = dyn_cast<StoreInst>(I))
- return S->getPointerAddressSpace();
- return -1;
-}
-
/// Returns true if the memory operations \p A and \p B are consecutive.
bool llvm::isConsecutiveAccess(Value *A, Value *B, const DataLayout &DL,
ScalarEvolution &SE, bool CheckType) {
Value *PtrA = getLoadStorePointerOperand(A);
Value *PtrB = getLoadStorePointerOperand(B);
- unsigned ASA = getAddressSpaceOperand(A);
- unsigned ASB = getAddressSpaceOperand(B);
-
- // Check that the address spaces match and that the pointers are valid.
- if (!PtrA || !PtrB || (ASA != ASB))
- return false;
-
- // Make sure that A and B are
diff erent pointers.
- if (PtrA == PtrB)
- return false;
-
- // Make sure that A and B have the same type if required.
- if (CheckType && PtrA->getType() != PtrB->getType())
+ if (!PtrA || !PtrB)
return false;
-
- unsigned IdxWidth = DL.getIndexSizeInBits(ASA);
- Type *Ty = cast<PointerType>(PtrA->getType())->getElementType();
-
- APInt OffsetA(IdxWidth, 0), OffsetB(IdxWidth, 0);
- PtrA = PtrA->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetA);
- PtrB = PtrB->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetB);
-
- // Retrieve the address space again as pointer stripping now tracks through
- // `addrspacecast`.
- ASA = cast<PointerType>(PtrA->getType())->getAddressSpace();
- ASB = cast<PointerType>(PtrB->getType())->getAddressSpace();
- // Check that the address spaces match and that the pointers are valid.
- if (ASA != ASB)
- return false;
-
- IdxWidth = DL.getIndexSizeInBits(ASA);
- OffsetA = OffsetA.sextOrTrunc(IdxWidth);
- OffsetB = OffsetB.sextOrTrunc(IdxWidth);
-
- APInt Size(IdxWidth, DL.getTypeStoreSize(Ty));
-
- // OffsetDelta = OffsetB - OffsetA;
- const SCEV *OffsetSCEVA = SE.getConstant(OffsetA);
- const SCEV *OffsetSCEVB = SE.getConstant(OffsetB);
- const SCEV *OffsetDeltaSCEV = SE.getMinusSCEV(OffsetSCEVB, OffsetSCEVA);
- const APInt &OffsetDelta = cast<SCEVConstant>(OffsetDeltaSCEV)->getAPInt();
-
- // Check if they are based on the same pointer. That makes the offsets
- // sufficient.
- if (PtrA == PtrB)
- return OffsetDelta == Size;
-
- // Compute the necessary base pointer delta to have the necessary final delta
- // equal to the size.
- // BaseDelta = Size - OffsetDelta;
- const SCEV *SizeSCEV = SE.getConstant(Size);
- const SCEV *BaseDelta = SE.getMinusSCEV(SizeSCEV, OffsetDeltaSCEV);
-
- // Otherwise compute the distance with SCEV between the base pointers.
- const SCEV *PtrSCEVA = SE.getSCEV(PtrA);
- const SCEV *PtrSCEVB = SE.getSCEV(PtrB);
- const SCEV *X = SE.getAddExpr(PtrSCEVA, BaseDelta);
- return X == PtrSCEVB;
+ Optional<int> Diff =
+ getPointersDiff(PtrA, PtrB, DL, SE, /*StrictCheck=*/true, CheckType);
+ return Diff && *Diff == 1;
}
MemoryDepChecker::VectorizationSafetyStatus
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 385b6f30dc0f..78d2ea0032db 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -941,10 +941,16 @@ class BoUpSLP {
ScalarEvolution &SE) {
auto *LI1 = dyn_cast<LoadInst>(V1);
auto *LI2 = dyn_cast<LoadInst>(V2);
- if (LI1 && LI2)
- return isConsecutiveAccess(LI1, LI2, DL, SE)
- ? VLOperands::ScoreConsecutiveLoads
- : VLOperands::ScoreFail;
+ if (LI1 && LI2) {
+ if (LI1->getParent() != LI2->getParent())
+ return VLOperands::ScoreFail;
+
+ Optional<int> Dist =
+ getPointersDiff(LI1->getPointerOperand(), LI2->getPointerOperand(),
+ DL, SE, /*StrictCheck=*/true);
+ return (Dist && *Dist == 1) ? VLOperands::ScoreConsecutiveLoads
+ : VLOperands::ScoreFail;
+ }
auto *C1 = dyn_cast<Constant>(V1);
auto *C2 = dyn_cast<Constant>(V2);
@@ -2871,13 +2877,9 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
Ptr0 = PointerOps[CurrentOrder.front()];
PtrN = PointerOps[CurrentOrder.back()];
}
- const SCEV *Scev0 = SE->getSCEV(Ptr0);
- const SCEV *ScevN = SE->getSCEV(PtrN);
- const auto *Diff =
- dyn_cast<SCEVConstant>(SE->getMinusSCEV(ScevN, Scev0));
- uint64_t Size = DL->getTypeAllocSize(ScalarTy);
+ Optional<int> Diff = getPointersDiff(Ptr0, PtrN, *DL, *SE);
// Check that the sorted loads are consecutive.
- if (Diff && Diff->getAPInt() == (VL.size() - 1) * Size) {
+ if (static_cast<unsigned>(*Diff) == VL.size() - 1) {
if (CurrentOrder.empty()) {
// Original loads are consecutive and does not require reordering.
++NumOpsWantToKeepOriginalOrder;
@@ -3150,13 +3152,9 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
Ptr0 = PointerOps[CurrentOrder.front()];
PtrN = PointerOps[CurrentOrder.back()];
}
- const SCEV *Scev0 = SE->getSCEV(Ptr0);
- const SCEV *ScevN = SE->getSCEV(PtrN);
- const auto *Diff =
- dyn_cast<SCEVConstant>(SE->getMinusSCEV(ScevN, Scev0));
- uint64_t Size = DL->getTypeAllocSize(ScalarTy);
+ Optional<int> Dist = getPointersDiff(Ptr0, PtrN, *DL, *SE);
// Check that the sorted pointer operands are consecutive.
- if (Diff && Diff->getAPInt() == (VL.size() - 1) * Size) {
+ if (static_cast<unsigned>(*Dist) == VL.size() - 1) {
if (CurrentOrder.empty()) {
// Original stores are consecutive and does not require reordering.
++NumOpsWantToKeepOriginalOrder;
@@ -6107,20 +6105,41 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
int E = Stores.size();
SmallBitVector Tails(E, false);
- SmallVector<int, 16> ConsecutiveChain(E, E + 1);
int MaxIter = MaxStoreLookup.getValue();
+ SmallVector<std::pair<int, int>, 16> ConsecutiveChain(
+ E, std::make_pair(E, INT_MAX));
+ SmallVector<SmallBitVector, 4> CheckedPairs(E, SmallBitVector(E, false));
int IterCnt;
auto &&FindConsecutiveAccess = [this, &Stores, &Tails, &IterCnt, MaxIter,
+ &CheckedPairs,
&ConsecutiveChain](int K, int Idx) {
if (IterCnt >= MaxIter)
return true;
+ if (CheckedPairs[Idx].test(K))
+ return ConsecutiveChain[K].second == 1 &&
+ ConsecutiveChain[K].first == Idx;
++IterCnt;
- if (!isConsecutiveAccess(Stores[K], Stores[Idx], *DL, *SE))
+ CheckedPairs[Idx].set(K);
+ CheckedPairs[K].set(Idx);
+ Optional<int> Diff = getPointersDiff(Stores[K]->getPointerOperand(),
+ Stores[Idx]->getPointerOperand(), *DL,
+ *SE, /*StrictCheck=*/true);
+ if (!Diff || *Diff == 0)
+ return false;
+ int Val = *Diff;
+ if (Val < 0) {
+ if (ConsecutiveChain[Idx].second > -Val) {
+ Tails.set(K);
+ ConsecutiveChain[Idx] = std::make_pair(K, -Val);
+ }
+ return false;
+ }
+ if (ConsecutiveChain[K].second <= Val)
return false;
Tails.set(Idx);
- ConsecutiveChain[K] = Idx;
- return true;
+ ConsecutiveChain[K] = std::make_pair(Idx, Val);
+ return Val == 1;
};
// Do a quadratic search on all of the given stores in reverse order and find
// all of the pairs of stores that follow each other.
@@ -6140,17 +6159,31 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
// For stores that start but don't end a link in the chain:
for (int Cnt = E; Cnt > 0; --Cnt) {
int I = Cnt - 1;
- if (ConsecutiveChain[I] == E + 1 || Tails.test(I))
+ if (ConsecutiveChain[I].first == E || Tails.test(I))
continue;
// We found a store instr that starts a chain. Now follow the chain and try
// to vectorize it.
BoUpSLP::ValueList Operands;
// Collect the chain into a list.
- while (I != E + 1 && !VectorizedStores.count(Stores[I])) {
+ while (I != E && !VectorizedStores.count(Stores[I])) {
Operands.push_back(Stores[I]);
+ Tails.set(I);
+ if (ConsecutiveChain[I].second != 1) {
+ // Mark the new end in the chain and go back, if required. It might be
+ // required if the original stores come in reversed order, for example.
+ if (ConsecutiveChain[I].first != E &&
+ Tails.test(ConsecutiveChain[I].first) &&
+ !VectorizedStores.count(Stores[ConsecutiveChain[I].first])) {
+ Tails.reset(ConsecutiveChain[I].first);
+ if (Cnt < ConsecutiveChain[I].first + 2)
+ Cnt = ConsecutiveChain[I].first + 2;
+ }
+ break;
+ }
// Move to the next value in the chain.
- I = ConsecutiveChain[I];
+ I = ConsecutiveChain[I].first;
}
+ assert(!Operands.empty() && "Expected non-empty list of stores.");
unsigned MaxVecRegSize = R.getMaxVecRegSize();
unsigned EltSize = R.getVectorElementSize(Operands[0]);
diff --git a/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll b/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
index 267cf1a02c29..e28362894910 100644
--- a/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
+++ b/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
@@ -1,7 +1,7 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -slp-vectorizer -slp-vectorizer -mattr=+sse2 -S | FileCheck %s --check-prefix=SSE
-; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -slp-vectorizer -slp-vectorizer -mattr=+avx -S | FileCheck %s --check-prefix=AVX
-; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -slp-vectorizer -slp-vectorizer -mattr=+avx2 -S | FileCheck %s --check-prefix=AVX
+; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -slp-vectorizer -mattr=+sse2 -S | FileCheck %s --check-prefix=SSE
+; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -slp-vectorizer -mattr=+avx -S | FileCheck %s --check-prefix=AVX
+; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -slp-vectorizer -mattr=+avx2 -S | FileCheck %s --check-prefix=AVX
%class.1 = type { %class.2 }
%class.2 = type { %"class.3" }
@@ -117,13 +117,10 @@ define void @pr35497() local_unnamed_addr #0 {
; AVX-NEXT: [[ARRAYIDX2_6:%.*]] = getelementptr inbounds [0 x i64], [0 x i64]* undef, i64 0, i64 0
; AVX-NEXT: [[TMP10:%.*]] = bitcast i64* [[ARRAYIDX2_6]] to <2 x i64>*
; AVX-NEXT: store <2 x i64> [[TMP4]], <2 x i64>* [[TMP10]], align 1
-; AVX-NEXT: [[TMP11:%.*]] = extractelement <2 x i64> [[TMP4]], i32 0
-; AVX-NEXT: [[TMP12:%.*]] = insertelement <2 x i64> poison, i64 [[TMP11]], i32 0
-; AVX-NEXT: [[TMP13:%.*]] = insertelement <2 x i64> [[TMP12]], i64 [[TMP5]], i32 1
-; AVX-NEXT: [[TMP14:%.*]] = lshr <2 x i64> [[TMP13]], <i64 6, i64 6>
-; AVX-NEXT: [[TMP15:%.*]] = add nuw nsw <2 x i64> [[TMP9]], [[TMP14]]
-; AVX-NEXT: [[TMP16:%.*]] = bitcast i64* [[ARRAYIDX2_2]] to <2 x i64>*
-; AVX-NEXT: store <2 x i64> [[TMP15]], <2 x i64>* [[TMP16]], align 1
+; AVX-NEXT: [[TMP11:%.*]] = lshr <2 x i64> [[TMP4]], <i64 6, i64 6>
+; AVX-NEXT: [[TMP12:%.*]] = add nuw nsw <2 x i64> [[TMP9]], [[TMP11]]
+; AVX-NEXT: [[TMP13:%.*]] = bitcast i64* [[ARRAYIDX2_2]] to <2 x i64>*
+; AVX-NEXT: store <2 x i64> [[TMP12]], <2 x i64>* [[TMP13]], align 1
; AVX-NEXT: ret void
;
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