[SLP]Add runtime stride support for strided loads. #81517
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Created using spr 1.3.5
|
@llvm/pr-subscribers-llvm-transforms Author: Alexey Bataev (alexey-bataev) ChangesAdded support for runtime strides. Full diff: https://github.com/llvm/llvm-project/pull/81517.diff 2 Files Affected:
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index c54d065cac6382..8fa32035d172d5 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -87,6 +87,7 @@
#include "llvm/Transforms/Utils/InjectTLIMappings.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
+#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
@@ -3890,6 +3891,122 @@ static bool isReverseOrder(ArrayRef<unsigned> Order) {
});
}
+/// Checks if the provided list of pointers \p Pointers represents the strided
+/// pointers for type ElemTy. If they are not, std::nullopt is returned.
+/// Otherwise, if \p Inst is not specified, just initialized optional value is
+/// returned to show that the pointers represent strided pointers. If \p Inst
+/// specified, the runtime stride is materialized before the given \p Inst.
+/// \returns std::nullopt if the pointers are not pointers with the runtime
+/// stride, nullptr or actual stride value, otherwise.
+static std::optional<Value *>
+calculateRtStride(ArrayRef<Value *> PointerOps, Type *ElemTy,
+ const DataLayout &DL, ScalarEvolution &SE,
+ SmallVectorImpl<unsigned> &SortedIndices,
+ Instruction *Inst = nullptr) {
+ SmallVector<const SCEV *> SCEVs;
+ const SCEV *PtrSCEVA = nullptr;
+ const SCEV *PtrSCEVB = nullptr;
+ for (Value *Ptr : PointerOps) {
+ const SCEV *PtrSCEV = SE.getSCEV(Ptr);
+ if (!PtrSCEV)
+ return std::nullopt;
+ SCEVs.push_back(PtrSCEV);
+ if (!PtrSCEVA && !PtrSCEVB) {
+ PtrSCEVA = PtrSCEVB = PtrSCEV;
+ continue;
+ }
+ const SCEV *Diff = SE.getMinusSCEV(PtrSCEV, PtrSCEVA);
+ if (!Diff || isa<SCEVCouldNotCompute>(Diff))
+ return std::nullopt;
+ if (Diff->isNonConstantNegative()) {
+ PtrSCEVA = PtrSCEV;
+ continue;
+ }
+ const SCEV *Diff1 = SE.getMinusSCEV(PtrSCEVB, PtrSCEV);
+ if (!Diff1 || isa<SCEVCouldNotCompute>(Diff1))
+ return std::nullopt;
+ if (Diff1->isNonConstantNegative()) {
+ PtrSCEVB = PtrSCEV;
+ continue;
+ }
+ }
+ const SCEV *Stride = SE.getMinusSCEV(PtrSCEVB, PtrSCEVA);
+ if (!Stride)
+ return std::nullopt;
+ int Size = DL.getTypeStoreSize(ElemTy);
+ auto TryGetStride = [&](const SCEV *Dist,
+ const SCEV *Multiplier) -> const SCEV * {
+ if (const auto *M = dyn_cast<SCEVMulExpr>(Dist)) {
+ if (M->getOperand(0) == Multiplier)
+ return M->getOperand(1);
+ if (M->getOperand(1) == Multiplier)
+ return M->getOperand(0);
+ return nullptr;
+ }
+ if (Multiplier == Dist)
+ return SE.getConstant(Dist->getType(), 1);
+ return SE.getUDivExactExpr(Dist, Multiplier);
+ };
+ if (Size != 1 || SCEVs.size() > 2) {
+ const SCEV *Sz =
+ SE.getConstant(Stride->getType(), Size * (SCEVs.size() - 1));
+ Stride = TryGetStride(Stride, Sz);
+ if (!Stride)
+ return std::nullopt;
+ }
+ if (!Stride || isa<SCEVConstant>(Stride))
+ return std::nullopt;
+ // Iterate through all pointers and check if all distances are
+ // unique multiple of Dist.
+ using DistOrdPair = std::pair<int64_t, int>;
+ auto Compare = llvm::less_first();
+ std::set<DistOrdPair, decltype(Compare)> Offsets(Compare);
+ int Cnt = 0;
+ bool IsConsecutive = true;
+ for (const SCEV *PtrSCEV : SCEVs) {
+ unsigned Dist = 0;
+ if (PtrSCEV != PtrSCEVA) {
+ const SCEV *Diff = SE.getMinusSCEV(PtrSCEV, PtrSCEVA);
+ const SCEV *Coeff = TryGetStride(Diff, Stride);
+ if (!Coeff)
+ return std::nullopt;
+ const auto *SC = dyn_cast<SCEVConstant>(Coeff);
+ if (!SC || isa<SCEVCouldNotCompute>(SC))
+ return std::nullopt;
+ if (!SE.getMinusSCEV(PtrSCEV,
+ SE.getAddExpr(PtrSCEVA, SE.getMulExpr(Stride, SC)))
+ ->isZero())
+ return std::nullopt;
+ Dist = SC->getAPInt().getZExtValue();
+ }
+ // If the strides are not the same or repeated, we can't vectorize.
+ if ((Dist / Size) * Size != Dist || (Dist / Size) >= SCEVs.size())
+ return std::nullopt;
+ auto Res = Offsets.emplace(Dist, Cnt);
+ if (!Res.second)
+ return std::nullopt;
+ // Consecutive order if the inserted element is the last one.
+ IsConsecutive = IsConsecutive && std::next(Res.first) == Offsets.end();
+ ++Cnt;
+ }
+ if (Offsets.size() != SCEVs.size())
+ return std::nullopt;
+ SortedIndices.clear();
+ if (!IsConsecutive) {
+ // Fill SortedIndices array only if it is non-consecutive.
+ SortedIndices.resize(PointerOps.size());
+ Cnt = 0;
+ for (const std::pair<int64_t, int> &Pair : Offsets) {
+ SortedIndices[Cnt] = Pair.second;
+ ++Cnt;
+ }
+ }
+ if (!Inst)
+ return nullptr;
+ SCEVExpander Expander(SE, DL, "strided-load-vec");
+ return Expander.expandCodeFor(Stride, Stride->getType(), Inst);
+}
+
/// Checks if the given array of loads can be represented as a vectorized,
/// scatter or just simple gather.
static LoadsState canVectorizeLoads(ArrayRef<Value *> VL, const Value *VL0,
@@ -3927,6 +4044,11 @@ static LoadsState canVectorizeLoads(ArrayRef<Value *> VL, const Value *VL0,
auto *VecTy = FixedVectorType::get(ScalarTy, Sz);
// Check the order of pointer operands or that all pointers are the same.
bool IsSorted = sortPtrAccesses(PointerOps, ScalarTy, DL, SE, Order);
+ Align CommonAlignment = computeCommonAlignment<LoadInst>(VL);
+ if (!IsSorted && Sz > MinProfitableStridedLoads && TTI.isTypeLegal(VecTy) &&
+ TTI.isLegalStridedLoadStore(VecTy, CommonAlignment) &&
+ calculateRtStride(PointerOps, ScalarTy, DL, SE, Order))
+ return LoadsState::StridedVectorize;
if (IsSorted || all_of(PointerOps, [&](Value *P) {
return arePointersCompatible(P, PointerOps.front(), TLI);
})) {
@@ -11645,10 +11767,30 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E, bool PostponedPHIs) {
std::optional<int> Diff = getPointersDiff(
VL0->getType(), Ptr0, VL0->getType(), PtrN, *DL, *SE);
Type *StrideTy = DL->getIndexType(PO->getType());
- int Stride = *Diff / (static_cast<int>(E->Scalars.size()) - 1);
- Value *StrideVal =
- ConstantInt::get(StrideTy, (IsReverseOrder ? -1 : 1) * Stride *
- DL->getTypeAllocSize(ScalarTy));
+ Value *StrideVal;
+ if (Diff) {
+ int Stride = *Diff / (static_cast<int>(E->Scalars.size()) - 1);
+ StrideVal =
+ ConstantInt::get(StrideTy, (IsReverseOrder ? -1 : 1) * Stride *
+ DL->getTypeAllocSize(ScalarTy));
+ } else {
+ SmallVector<Value *> PointerOps(E->Scalars.size(), nullptr);
+ transform(E->Scalars, PointerOps.begin(), [](Value *V) {
+ return cast<LoadInst>(V)->getPointerOperand();
+ });
+ OrdersType Order;
+ std::optional<Value *> Stride =
+ calculateRtStride(PointerOps, ScalarTy, *DL, *SE, Order,
+ &*Builder.GetInsertPoint());
+ Value *NewStride =
+ Builder.CreateIntCast(*Stride, StrideTy, /*isSigned=*/true);
+ StrideVal = Builder.CreateMul(
+ NewStride,
+ ConstantInt::get(
+ StrideTy,
+ (IsReverseOrder ? -1 : 1) *
+ static_cast<int>(DL->getTypeAllocSize(ScalarTy))));
+ }
Align CommonAlignment = computeCommonAlignment<LoadInst>(E->Scalars);
auto *Inst = Builder.CreateIntrinsic(
Intrinsic::experimental_vp_strided_load,
diff --git a/llvm/test/Transforms/SLPVectorizer/RISCV/strided-loads-vectorized.ll b/llvm/test/Transforms/SLPVectorizer/RISCV/strided-loads-vectorized.ll
index 4b0b41970bbb4d..03acc0009fb04c 100644
--- a/llvm/test/Transforms/SLPVectorizer/RISCV/strided-loads-vectorized.ll
+++ b/llvm/test/Transforms/SLPVectorizer/RISCV/strided-loads-vectorized.ll
@@ -78,67 +78,13 @@ define void @test1(ptr %p, ptr noalias %s, i32 %stride) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[STR:%.*]] = zext i32 [[STRIDE:%.*]] to i64
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [48 x float], ptr [[P:%.*]], i64 0, i64 0
-; CHECK-NEXT: [[I:%.*]] = load float, ptr [[ARRAYIDX]], align 4
; CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 30
-; CHECK-NEXT: [[I1:%.*]] = load float, ptr [[ARRAYIDX1]], align 4
-; CHECK-NEXT: [[ADD:%.*]] = fsub fast float [[I1]], [[I]]
; CHECK-NEXT: [[ARRAYIDX2:%.*]] = getelementptr inbounds float, ptr [[S:%.*]], i64 0
-; CHECK-NEXT: store float [[ADD]], ptr [[ARRAYIDX2]], align 4
-; CHECK-NEXT: [[ARRAYIDX4:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[STR]]
-; CHECK-NEXT: [[I2:%.*]] = load float, ptr [[ARRAYIDX4]], align 4
-; CHECK-NEXT: [[ARRAYIDX6:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 26
-; CHECK-NEXT: [[I3:%.*]] = load float, ptr [[ARRAYIDX6]], align 4
-; CHECK-NEXT: [[ADD7:%.*]] = fsub fast float [[I3]], [[I2]]
-; CHECK-NEXT: [[ARRAYIDX9:%.*]] = getelementptr inbounds float, ptr [[S]], i64 1
-; CHECK-NEXT: store float [[ADD7]], ptr [[ARRAYIDX9]], align 4
-; CHECK-NEXT: [[ST1:%.*]] = mul i64 [[STR]], 2
-; CHECK-NEXT: [[ARRAYIDX11:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST1]]
-; CHECK-NEXT: [[I4:%.*]] = load float, ptr [[ARRAYIDX11]], align 4
-; CHECK-NEXT: [[ARRAYIDX13:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 22
-; CHECK-NEXT: [[I5:%.*]] = load float, ptr [[ARRAYIDX13]], align 4
-; CHECK-NEXT: [[ADD14:%.*]] = fsub fast float [[I5]], [[I4]]
-; CHECK-NEXT: [[ARRAYIDX16:%.*]] = getelementptr inbounds float, ptr [[S]], i64 2
-; CHECK-NEXT: store float [[ADD14]], ptr [[ARRAYIDX16]], align 4
-; CHECK-NEXT: [[ST2:%.*]] = mul i64 [[STR]], 3
-; CHECK-NEXT: [[ARRAYIDX18:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST2]]
-; CHECK-NEXT: [[I6:%.*]] = load float, ptr [[ARRAYIDX18]], align 4
-; CHECK-NEXT: [[ARRAYIDX20:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 18
-; CHECK-NEXT: [[I7:%.*]] = load float, ptr [[ARRAYIDX20]], align 4
-; CHECK-NEXT: [[ADD21:%.*]] = fsub fast float [[I7]], [[I6]]
-; CHECK-NEXT: [[ARRAYIDX23:%.*]] = getelementptr inbounds float, ptr [[S]], i64 3
-; CHECK-NEXT: store float [[ADD21]], ptr [[ARRAYIDX23]], align 4
-; CHECK-NEXT: [[ST3:%.*]] = mul i64 [[STR]], 4
-; CHECK-NEXT: [[ARRAYIDX25:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST3]]
-; CHECK-NEXT: [[I8:%.*]] = load float, ptr [[ARRAYIDX25]], align 4
-; CHECK-NEXT: [[ARRAYIDX27:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 14
-; CHECK-NEXT: [[I9:%.*]] = load float, ptr [[ARRAYIDX27]], align 4
-; CHECK-NEXT: [[ADD28:%.*]] = fsub fast float [[I9]], [[I8]]
-; CHECK-NEXT: [[ARRAYIDX30:%.*]] = getelementptr inbounds float, ptr [[S]], i64 4
-; CHECK-NEXT: store float [[ADD28]], ptr [[ARRAYIDX30]], align 4
-; CHECK-NEXT: [[ST4:%.*]] = mul i64 [[STR]], 5
-; CHECK-NEXT: [[ARRAYIDX32:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST4]]
-; CHECK-NEXT: [[I10:%.*]] = load float, ptr [[ARRAYIDX32]], align 4
-; CHECK-NEXT: [[ARRAYIDX34:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 10
-; CHECK-NEXT: [[I11:%.*]] = load float, ptr [[ARRAYIDX34]], align 4
-; CHECK-NEXT: [[ADD35:%.*]] = fsub fast float [[I11]], [[I10]]
-; CHECK-NEXT: [[ARRAYIDX37:%.*]] = getelementptr inbounds float, ptr [[S]], i64 5
-; CHECK-NEXT: store float [[ADD35]], ptr [[ARRAYIDX37]], align 4
-; CHECK-NEXT: [[ST5:%.*]] = mul i64 [[STR]], 6
-; CHECK-NEXT: [[ARRAYIDX39:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST5]]
-; CHECK-NEXT: [[I12:%.*]] = load float, ptr [[ARRAYIDX39]], align 4
-; CHECK-NEXT: [[ARRAYIDX41:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 6
-; CHECK-NEXT: [[I13:%.*]] = load float, ptr [[ARRAYIDX41]], align 4
-; CHECK-NEXT: [[ADD42:%.*]] = fsub fast float [[I13]], [[I12]]
-; CHECK-NEXT: [[ARRAYIDX44:%.*]] = getelementptr inbounds float, ptr [[S]], i64 6
-; CHECK-NEXT: store float [[ADD42]], ptr [[ARRAYIDX44]], align 4
-; CHECK-NEXT: [[ST6:%.*]] = mul i64 [[STR]], 7
-; CHECK-NEXT: [[ARRAYIDX46:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST6]]
-; CHECK-NEXT: [[I14:%.*]] = load float, ptr [[ARRAYIDX46]], align 4
-; CHECK-NEXT: [[ARRAYIDX48:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 2
-; CHECK-NEXT: [[I15:%.*]] = load float, ptr [[ARRAYIDX48]], align 4
-; CHECK-NEXT: [[ADD49:%.*]] = fsub fast float [[I15]], [[I14]]
-; CHECK-NEXT: [[ARRAYIDX51:%.*]] = getelementptr inbounds float, ptr [[S]], i64 7
-; CHECK-NEXT: store float [[ADD49]], ptr [[ARRAYIDX51]], align 4
+; CHECK-NEXT: [[TMP0:%.*]] = mul i64 [[STR]], 4
+; CHECK-NEXT: [[TMP1:%.*]] = call <8 x float> @llvm.experimental.vp.strided.load.v8f32.p0.i64(ptr align 4 [[ARRAYIDX]], i64 [[TMP0]], <8 x i1> <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>, i32 8)
+; CHECK-NEXT: [[TMP2:%.*]] = call <8 x float> @llvm.experimental.vp.strided.load.v8f32.p0.i64(ptr align 4 [[ARRAYIDX1]], i64 -16, <8 x i1> <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>, i32 8)
+; CHECK-NEXT: [[TMP3:%.*]] = fsub fast <8 x float> [[TMP2]], [[TMP1]]
+; CHECK-NEXT: store <8 x float> [[TMP3]], ptr [[ARRAYIDX2]], align 4
; CHECK-NEXT: ret void
;
entry:
@@ -215,38 +161,12 @@ define void @test2(ptr %p, ptr noalias %s, i32 %stride) {
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [48 x float], ptr [[P:%.*]], i64 0, i64 2
; CHECK-NEXT: [[ST6:%.*]] = mul i64 [[STR]], 7
; CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST6]]
-; CHECK-NEXT: [[I1:%.*]] = load float, ptr [[ARRAYIDX1]], align 4
; CHECK-NEXT: [[ARRAYIDX2:%.*]] = getelementptr inbounds float, ptr [[S:%.*]], i64 0
-; CHECK-NEXT: [[ST5:%.*]] = mul i64 [[STR]], 6
-; CHECK-NEXT: [[ARRAYIDX6:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST5]]
-; CHECK-NEXT: [[I3:%.*]] = load float, ptr [[ARRAYIDX6]], align 4
-; CHECK-NEXT: [[ST4:%.*]] = mul i64 [[STR]], 5
-; CHECK-NEXT: [[ARRAYIDX13:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST4]]
-; CHECK-NEXT: [[I5:%.*]] = load float, ptr [[ARRAYIDX13]], align 4
-; CHECK-NEXT: [[ST3:%.*]] = mul i64 [[STR]], 4
-; CHECK-NEXT: [[ARRAYIDX20:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST3]]
-; CHECK-NEXT: [[I7:%.*]] = load float, ptr [[ARRAYIDX20]], align 4
-; CHECK-NEXT: [[ST2:%.*]] = mul i64 [[STR]], 3
-; CHECK-NEXT: [[ARRAYIDX27:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST2]]
-; CHECK-NEXT: [[I9:%.*]] = load float, ptr [[ARRAYIDX27]], align 4
-; CHECK-NEXT: [[ST1:%.*]] = mul i64 [[STR]], 2
-; CHECK-NEXT: [[ARRAYIDX34:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[ST1]]
-; CHECK-NEXT: [[I11:%.*]] = load float, ptr [[ARRAYIDX34]], align 4
-; CHECK-NEXT: [[ARRAYIDX41:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 [[STR]]
-; CHECK-NEXT: [[I13:%.*]] = load float, ptr [[ARRAYIDX41]], align 4
-; CHECK-NEXT: [[ARRAYIDX48:%.*]] = getelementptr inbounds [48 x float], ptr [[P]], i64 0, i64 0
-; CHECK-NEXT: [[I15:%.*]] = load float, ptr [[ARRAYIDX48]], align 4
; CHECK-NEXT: [[TMP0:%.*]] = call <8 x float> @llvm.experimental.vp.strided.load.v8f32.p0.i64(ptr align 4 [[ARRAYIDX]], i64 16, <8 x i1> <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>, i32 8)
-; CHECK-NEXT: [[TMP1:%.*]] = insertelement <8 x float> poison, float [[I1]], i32 0
-; CHECK-NEXT: [[TMP2:%.*]] = insertelement <8 x float> [[TMP1]], float [[I3]], i32 1
-; CHECK-NEXT: [[TMP3:%.*]] = insertelement <8 x float> [[TMP2]], float [[I5]], i32 2
-; CHECK-NEXT: [[TMP4:%.*]] = insertelement <8 x float> [[TMP3]], float [[I7]], i32 3
-; CHECK-NEXT: [[TMP5:%.*]] = insertelement <8 x float> [[TMP4]], float [[I9]], i32 4
-; CHECK-NEXT: [[TMP6:%.*]] = insertelement <8 x float> [[TMP5]], float [[I11]], i32 5
-; CHECK-NEXT: [[TMP7:%.*]] = insertelement <8 x float> [[TMP6]], float [[I13]], i32 6
-; CHECK-NEXT: [[TMP8:%.*]] = insertelement <8 x float> [[TMP7]], float [[I15]], i32 7
-; CHECK-NEXT: [[TMP9:%.*]] = fsub fast <8 x float> [[TMP8]], [[TMP0]]
-; CHECK-NEXT: store <8 x float> [[TMP9]], ptr [[ARRAYIDX2]], align 4
+; CHECK-NEXT: [[TMP1:%.*]] = mul i64 [[STR]], -4
+; CHECK-NEXT: [[TMP2:%.*]] = call <8 x float> @llvm.experimental.vp.strided.load.v8f32.p0.i64(ptr align 4 [[ARRAYIDX1]], i64 [[TMP1]], <8 x i1> <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>, i32 8)
+; CHECK-NEXT: [[TMP3:%.*]] = fsub fast <8 x float> [[TMP2]], [[TMP0]]
+; CHECK-NEXT: store <8 x float> [[TMP3]], ptr [[ARRAYIDX2]], align 4
; CHECK-NEXT: ret void
;
entry:
|
preames
reviewed
Feb 20, 2024
| const SCEV *Diff = SE.getMinusSCEV(PtrSCEV, PtrSCEVA); | ||
| if (!Diff || isa<SCEVCouldNotCompute>(Diff)) | ||
| return std::nullopt; | ||
| if (Diff->isNonConstantNegative()) { |
There was a problem hiding this comment.
Why is isNonConstant part? Why not isKnownNegative?
preames
approved these changes
Mar 4, 2024
There was a problem hiding this comment.
LGTM
I'll comment that I find the guess and check style logic used in this patch to be very confusing without clear comments as to exactly what's going on. I think you could make this much clearer if you used appropriate variable names, or at least some clear comments about the point where you transfer from best effort guessing to checking your result and relying on it's correctness.
Renamed the variables, added some more comments |
Created using spr 1.3.5
alexey-bataev
deleted the
users/alexey-bataev/spr/slpadd-runtime-stride-support-for-strided-loads
branch
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Added support for runtime strides.