[llvm] [SLP]Add subvector vectorization for non-load nodes (PR #108430)

[Alexey Bataev via llvm-commits]

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@@ -8447,47 +8454,147 @@ getGEPCosts(const TargetTransformInfo &TTI, ArrayRef<Value *> Ptrs,
 
 void BoUpSLP::transformNodes() {
   constexpr TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
+  BaseGraphSize = VectorizableTree.size();
+  // Operands are profitable if all of them are:
+  // 1. Constants
+  // or
+  // 2. Splats
+  // or
+  // 3. Results in good vectorization opportunity, i.e. may generate vector
+  // nodes and reduce cost of the graph.
+  auto CheckOperandsProfitability = [this](Instruction *I1, Instruction *I2,
+                                           const InstructionsState &S) {
+    SmallVector<SmallVector<std::pair<Value *, Value *>>> Candidates;
+    for (unsigned Op : seq<unsigned>(S.MainOp->getNumOperands()))
+      Candidates.emplace_back().emplace_back(I1->getOperand(Op),
+                                             I2->getOperand(Op));
+    return all_of(Candidates, [this](
+                                  ArrayRef<std::pair<Value *, Value *>> Cand) {
+      return all_of(Cand,
+                    [](const std::pair<Value *, Value *> &P) {
+                      return isa<Constant>(P.first) ||
+                             isa<Constant>(P.second) || (P.first == P.second);
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alexey-bataev wrote:

I will update the comment and remove extra parens

https://github.com/llvm/llvm-project/pull/108430