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[VPlan] Remove hoisting to preheader in VPTransformState::get #142594

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[VPlan] Remove hoisting to preheader in VPTransformState::get #142594

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30 changes: 4 additions & 26 deletions llvm/lib/Transforms/Vectorize/VPlan.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -289,34 +289,12 @@ Value *VPTransformState::get(const VPValue *Def, bool NeedsScalar) {
if (hasVectorValue(Def))
return Data.VPV2Vector[Def];

auto GetBroadcastInstrs = [this, Def](Value *V) {
bool SafeToHoist =
!Def->hasDefiningRecipe() ||
VPDT.properlyDominates(Def->getDefiningRecipe()->getParent(),
Plan->getVectorPreheader());

if (VF.isScalar())
return V;
// Place the code for broadcasting invariant variables in the new preheader.
IRBuilder<>::InsertPointGuard Guard(Builder);
if (SafeToHoist) {
BasicBlock *LoopVectorPreHeader =
CFG.VPBB2IRBB[Plan->getVectorPreheader()];
if (LoopVectorPreHeader)
Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator());
}

// Place the code for broadcasting invariant variables in the new preheader.
// Broadcast the scalar into all locations in the vector.
Value *Shuf = Builder.CreateVectorSplat(VF, V, "broadcast");

return Shuf;
};

if (!hasScalarValue(Def, {0})) {
assert(Def->isLiveIn() && "expected a live-in");
Value *IRV = Def->getLiveInIRValue();
Value *B = GetBroadcastInstrs(IRV);
if (VF.isScalar())
return IRV;
Value *B = Builder.CreateVectorSplat(VF, IRV, "broadcast");
set(Def, B);
return B;
}
Expand Down Expand Up @@ -361,7 +339,7 @@ Value *VPTransformState::get(const VPValue *Def, bool NeedsScalar) {
// insertelements once.
Value *VectorValue = nullptr;
if (IsSingleScalar) {
VectorValue = GetBroadcastInstrs(ScalarValue);
VectorValue = Builder.CreateVectorSplat(VF, ScalarValue, "broadcast");
set(Def, VectorValue);
} else {
// Initialize packing with insertelements to start from undef.
Expand Down