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[SLP]Make PHICompare comparator follow weak strict ordering requirement #110529

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86 changes: 74 additions & 12 deletions llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -5447,6 +5447,33 @@ BoUpSLP::getReorderingData(const TreeEntry &TE, bool TopToBottom) {
if (!TE.ReorderIndices.empty())
return TE.ReorderIndices;

SmallVector<Instruction *> UserBVHead(TE.Scalars.size());
for (auto [I, V] : zip(UserBVHead, TE.Scalars)) {
if (!V->hasNUsesOrMore(1))
continue;
auto *II = dyn_cast<InsertElementInst>(*V->user_begin());
if (!II)
continue;
Instruction *BVHead = nullptr;
BasicBlock *BB = II->getParent();
while (II && II->hasOneUse() && II->getParent() == BB) {
BVHead = II;
II = dyn_cast<InsertElementInst>(II->getOperand(0));
}
I = BVHead;
}

auto CompareByBasicBlocks = [&](BasicBlock *BB1, BasicBlock *BB2) {
assert(BB1 != BB2 && "Expected different basic blocks.");
auto *NodeA = DT->getNode(BB1);
auto *NodeB = DT->getNode(BB2);
assert(NodeA && "Should only process reachable instructions");
assert(NodeB && "Should only process reachable instructions");
assert((NodeA == NodeB) ==
(NodeA->getDFSNumIn() == NodeB->getDFSNumIn()) &&
"Different nodes should have different DFS numbers");
return NodeA->getDFSNumIn() < NodeB->getDFSNumIn();
};
auto PHICompare = [&](unsigned I1, unsigned I2) {
Value *V1 = TE.Scalars[I1];
Value *V2 = TE.Scalars[I2];
Expand All @@ -5458,21 +5485,56 @@ BoUpSLP::getReorderingData(const TreeEntry &TE, bool TopToBottom) {
return false;
auto *FirstUserOfPhi1 = cast<Instruction>(*V1->user_begin());
auto *FirstUserOfPhi2 = cast<Instruction>(*V2->user_begin());
if (auto *IE1 = dyn_cast<InsertElementInst>(FirstUserOfPhi1))
if (auto *IE2 = dyn_cast<InsertElementInst>(FirstUserOfPhi2)) {
if (!areTwoInsertFromSameBuildVector(
IE1, IE2,
[](InsertElementInst *II) { return II->getOperand(0); }))
return I1 < I2;
if (FirstUserOfPhi1->getParent() != FirstUserOfPhi2->getParent())
return CompareByBasicBlocks(FirstUserOfPhi1->getParent(),
FirstUserOfPhi2->getParent());
auto *IE1 = dyn_cast<InsertElementInst>(FirstUserOfPhi1);
auto *IE2 = dyn_cast<InsertElementInst>(FirstUserOfPhi2);
auto *EE1 = dyn_cast<ExtractElementInst>(FirstUserOfPhi1);
auto *EE2 = dyn_cast<ExtractElementInst>(FirstUserOfPhi2);
if (IE1 && !IE2)
return true;
if (!IE1 && IE2)
return false;
if (IE1 && IE2) {
if (UserBVHead[I1] && !UserBVHead[I2])
return true;
if (!UserBVHead[I1])
return false;
if (UserBVHead[I1] == UserBVHead[I2])
return getElementIndex(IE1) < getElementIndex(IE2);
}
if (auto *EE1 = dyn_cast<ExtractElementInst>(FirstUserOfPhi1))
if (auto *EE2 = dyn_cast<ExtractElementInst>(FirstUserOfPhi2)) {
if (EE1->getOperand(0) != EE2->getOperand(0))
return I1 < I2;
if (UserBVHead[I1]->getParent() != UserBVHead[I2]->getParent())
return CompareByBasicBlocks(UserBVHead[I1]->getParent(),
UserBVHead[I2]->getParent());
return UserBVHead[I1]->comesBefore(UserBVHead[I2]);
}
if (EE1 && !EE2)
return true;
if (!EE1 && EE2)
return false;
if (EE1 && EE2) {
auto *Inst1 = dyn_cast<Instruction>(EE1->getOperand(0));
auto *Inst2 = dyn_cast<Instruction>(EE2->getOperand(0));
auto *P1 = dyn_cast<Argument>(EE1->getOperand(0));
auto *P2 = dyn_cast<Argument>(EE2->getOperand(0));
if (!Inst2 && !P2)
return Inst1 || P1;
if (EE1->getOperand(0) == EE2->getOperand(0))
return getElementIndex(EE1) < getElementIndex(EE2);
if (!Inst1 && Inst2)
return false;
if (Inst1 && Inst2) {
if (Inst1->getParent() != Inst2->getParent())
return CompareByBasicBlocks(Inst1->getParent(), Inst2->getParent());
return Inst1->comesBefore(Inst2);
}
return I1 < I2;
if (!P1 && P2)
return false;
assert(P1 && P2 &&
"Expected either instructions or arguments vector operands.");
return P1->getArgNo() < P2->getArgNo();
}
return false;
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This doesn't quite work... if the first operand isn't an instruction or an argument, we have to always return false. So this needs to happen before the if (EE1->getOperand(0) == EE2->getOperand(0)).

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I think it already does this. if (EE1->getOperand(0) == EE2->getOperand(0)) occurs only if both users are extractelements, argument comparison occurs only if both users are arguments. If the first is extract/argument but the second is not - return true. If the first is not extract/argument - return false. Am I missing something?

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Suppose you have three extractelements with a constant as the first operand. Two of them have A as the first operand, the other one has B as the first operand. They all need to compare equal, even if the extract indexes are different.

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Ah, missed it, fixed

};
SmallDenseMap<unsigned, unsigned, 16> PhiToId;
SmallVector<unsigned> Phis(TE.Scalars.size());
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -33,40 +33,40 @@ define void @test() {
; CHECK-NEXT: [[TMP7:%.*]] = insertelement <16 x float> [[TMP6]], float [[I68]], i32 6
; CHECK-NEXT: [[TMP8:%.*]] = insertelement <16 x float> [[TMP7]], float [[I66]], i32 7
; CHECK-NEXT: [[TMP9:%.*]] = insertelement <16 x float> [[TMP8]], float [[I72]], i32 13
; CHECK-NEXT: [[TMP10:%.*]] = insertelement <16 x float> [[TMP9]], float [[I69]], i32 14
; CHECK-NEXT: [[TMP11:%.*]] = insertelement <16 x float> [[TMP10]], float [[I67]], i32 15
; CHECK-NEXT: [[TMP10:%.*]] = insertelement <16 x float> [[TMP9]], float [[I67]], i32 14
; CHECK-NEXT: [[TMP11:%.*]] = insertelement <16 x float> [[TMP10]], float [[I69]], i32 15
; CHECK-NEXT: br i1 poison, label %[[BB167:.*]], label %[[BB77:.*]]
; CHECK: [[BB77]]:
; CHECK-NEXT: [[TMP12:%.*]] = shufflevector <16 x float> [[TMP11]], <16 x float> poison, <8 x i32> <i32 poison, i32 5, i32 6, i32 7, i32 15, i32 15, i32 14, i32 15>
; CHECK-NEXT: [[TMP12:%.*]] = shufflevector <16 x float> [[TMP11]], <16 x float> poison, <8 x i32> <i32 poison, i32 5, i32 6, i32 7, i32 14, i32 14, i32 14, i32 15>
; CHECK-NEXT: [[TMP13:%.*]] = shufflevector <2 x float> [[TMP0]], <2 x float> poison, <16 x i32> <i32 poison, i32 poison, i32 1, i32 0, i32 0, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 1, i32 poison, i32 poison>
; CHECK-NEXT: [[TMP14:%.*]] = shufflevector <2 x float> [[TMP0]], <2 x float> poison, <16 x i32> <i32 poison, i32 poison, i32 poison, i32 poison, i32 1, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 0, i32 poison, i32 poison>
; CHECK-NEXT: br label %[[BB78:.*]]
; CHECK: [[BB78]]:
; CHECK-NEXT: [[TMP15:%.*]] = phi <8 x float> [ [[TMP12]], %[[BB77]] ], [ [[TMP30:%.*]], %[[BB78]] ]
; CHECK-NEXT: [[TMP16:%.*]] = phi <2 x float> [ poison, %[[BB77]] ], [ [[TMP31:%.*]], %[[BB78]] ]
; CHECK-NEXT: [[TMP17:%.*]] = shufflevector <8 x float> [[TMP15]], <8 x float> poison, <16 x i32> <i32 0, i32 3, i32 1, i32 2, i32 3, i32 0, i32 2, i32 3, i32 2, i32 7, i32 2, i32 3, i32 0, i32 6, i32 7, i32 7>
; CHECK-NEXT: [[TMP17:%.*]] = shufflevector <8 x float> [[TMP15]], <8 x float> poison, <16 x i32> <i32 0, i32 3, i32 1, i32 2, i32 3, i32 0, i32 2, i32 3, i32 2, i32 6, i32 2, i32 3, i32 0, i32 7, i32 6, i32 6>
; CHECK-NEXT: [[TMP18:%.*]] = fmul fast <16 x float> [[TMP17]], [[TMP13]]
; CHECK-NEXT: [[TMP19:%.*]] = shufflevector <8 x float> [[TMP15]], <8 x float> poison, <16 x i32> <i32 1, i32 poison, i32 0, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 1, i32 7, i32 6, i32 6>
; CHECK-NEXT: [[TMP19:%.*]] = shufflevector <8 x float> [[TMP15]], <8 x float> poison, <16 x i32> <i32 1, i32 poison, i32 0, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 1, i32 6, i32 7, i32 7>
; CHECK-NEXT: [[TMP20:%.*]] = shufflevector <2 x float> [[TMP16]], <2 x float> poison, <16 x i32> <i32 0, i32 1, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison>
; CHECK-NEXT: [[TMP21:%.*]] = shufflevector <16 x float> [[TMP19]], <16 x float> [[TMP20]], <16 x i32> <i32 0, i32 17, i32 2, i32 16, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 12, i32 13, i32 14, i32 15>
; CHECK-NEXT: [[TMP22:%.*]] = shufflevector <8 x float> [[TMP15]], <8 x float> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison>
; CHECK-NEXT: [[TMP23:%.*]] = shufflevector <16 x float> [[TMP21]], <16 x float> [[TMP22]], <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 17, i32 6, i32 7, i32 8, i32 22, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
; CHECK-NEXT: [[TMP23:%.*]] = shufflevector <16 x float> [[TMP21]], <16 x float> [[TMP22]], <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 17, i32 6, i32 7, i32 8, i32 23, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
; CHECK-NEXT: [[TMP24:%.*]] = shufflevector <16 x float> [[TMP23]], <16 x float> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 1, i32 5, i32 3, i32 1, i32 3, i32 9, i32 3, i32 1, i32 12, i32 13, i32 14, i32 15>
; CHECK-NEXT: [[TMP25:%.*]] = call <16 x float> @llvm.vector.insert.v16f32.v2f32(<16 x float> [[TMP14]], <2 x float> [[TMP0]], i64 2)
; CHECK-NEXT: [[TMP26:%.*]] = fmul fast <16 x float> [[TMP24]], [[TMP25]]
; CHECK-NEXT: [[TMP27:%.*]] = fadd fast <16 x float> [[TMP26]], [[TMP18]]
; CHECK-NEXT: [[TMP28:%.*]] = fadd fast <16 x float> [[TMP27]], poison
; CHECK-NEXT: [[TMP29:%.*]] = fadd fast <16 x float> [[TMP28]], poison
; CHECK-NEXT: [[TMP30]] = shufflevector <16 x float> [[TMP29]], <16 x float> poison, <8 x i32> <i32 12, i32 5, i32 6, i32 7, i32 15, i32 15, i32 14, i32 15>
; CHECK-NEXT: [[TMP30]] = shufflevector <16 x float> [[TMP29]], <16 x float> poison, <8 x i32> <i32 12, i32 5, i32 6, i32 7, i32 14, i32 14, i32 14, i32 15>
; CHECK-NEXT: [[TMP31]] = shufflevector <16 x float> [[TMP29]], <16 x float> poison, <2 x i32> <i32 10, i32 11>
; CHECK-NEXT: br i1 poison, label %[[BB78]], label %[[BB167]]
; CHECK: [[BB167]]:
; CHECK-NEXT: [[TMP32:%.*]] = phi <16 x float> [ [[TMP11]], %[[BB64]] ], [ [[TMP29]], %[[BB78]] ]
; CHECK-NEXT: [[TMP33:%.*]] = extractelement <16 x float> [[TMP32]], i32 15
; CHECK-NEXT: [[TMP33:%.*]] = extractelement <16 x float> [[TMP32]], i32 14
; CHECK-NEXT: store float [[TMP33]], ptr poison, align 1
; CHECK-NEXT: [[TMP34:%.*]] = extractelement <16 x float> [[TMP32]], i32 13
; CHECK-NEXT: store float [[TMP34]], ptr poison, align 1
; CHECK-NEXT: [[TMP35:%.*]] = extractelement <16 x float> [[TMP32]], i32 14
; CHECK-NEXT: [[TMP35:%.*]] = extractelement <16 x float> [[TMP32]], i32 15
; CHECK-NEXT: br i1 poison, label %[[BB186:.*]], label %[[BB184:.*]]
; CHECK: [[BB184]]:
; CHECK-NEXT: br label %[[BB185:.*]]
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -10,9 +10,9 @@ define i1 @test() {
; CHECK-NEXT: br label [[ELSE]]
; CHECK: else:
; CHECK-NEXT: [[TMP0:%.*]] = phi <2 x i32> [ zeroinitializer, [[THEN]] ], [ zeroinitializer, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[TMP1:%.*]] = extractelement <2 x i32> [[TMP0]], i32 0
; CHECK-NEXT: [[TMP1:%.*]] = extractelement <2 x i32> [[TMP0]], i32 1
; CHECK-NEXT: [[BF_CAST162:%.*]] = and i32 [[TMP1]], 0
; CHECK-NEXT: [[TMP2:%.*]] = shufflevector <2 x i32> zeroinitializer, <2 x i32> [[TMP0]], <2 x i32> <i32 3, i32 1>
; CHECK-NEXT: [[TMP2:%.*]] = shufflevector <2 x i32> zeroinitializer, <2 x i32> [[TMP0]], <2 x i32> <i32 2, i32 1>
; CHECK-NEXT: [[T13:%.*]] = and <2 x i32> [[TMP2]], zeroinitializer
; CHECK-NEXT: br label [[ELSE1:%.*]]
; CHECK: else1:
Expand Down
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