[llvm] [LV] Support binary and unary operations with EVL-vectorization (PR #93854)

[Florian Hahn via llvm-commits]

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@@ -1443,6 +1458,54 @@ class VPWidenRecipe : public VPRecipeWithIRFlags {
 #endif
 };
 
+/// A recipe for widening operations with vector-predication intrinsics with
+/// explicit vector length (EVL).
+class VPWidenEVLRecipe : public VPWidenRecipe {
+  using VPRecipeWithIRFlags::transferFlags;
+
+public:
+  template <typename IterT>
+  VPWidenEVLRecipe(Instruction &I, iterator_range<IterT> Operands, VPValue &EVL)
+      : VPWidenRecipe(VPDef::VPWidenEVLSC, I, Operands) {
+    addOperand(&EVL);
+  }
+  VPWidenEVLRecipe(VPWidenRecipe &W, VPValue &EVL)
+      : VPWidenEVLRecipe(*W.getUnderlyingInstr(), W.operands(), EVL) {
+    transferFlags(W);
+  }
+
+  ~VPWidenEVLRecipe() override = default;
+
+  VPWidenRecipe *clone() override final {
+    llvm_unreachable("VPWidenEVLRecipe cannot be cloned");
+    return nullptr;
+  }
+
+  VP_CLASSOF_IMPL(VPDef::VPWidenEVLSC);
+
+  VPValue *getEVL() { return getOperand(getNumOperands() - 1); }
+  const VPValue *getEVL() const { return getOperand(getNumOperands() - 1); }
+
+  /// Produce a vp-intrinsic using the opcode and operands of the recipe,
+  /// processing EVL elements.
+  void execute(VPTransformState &State) override final;
+
+  /// Returns true if the recipe only uses the first lane of operand \p Op.
+  bool onlyFirstLaneUsed(const VPValue *Op) const override {
+    assert(is_contained(operands(), Op) &&
+           "Op must be an operand of the recipe");
+    // EVL in that recipe is always the last operand, thus any use before means
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fhahn wrote:

Would be good to post a follow-up patch to enforce EVL only used as last operand of various recipes in the verifier

https://github.com/llvm/llvm-project/pull/93854