[llvm] [LV][EVL] Support icmp/fcmp instruction with EVL-vectorization (PR #108533)

[Ramkumar Ramachandra via llvm-commits]

================
@@ -1353,6 +1353,34 @@ InstructionCost VPWidenRecipe::computeCost(ElementCount VF,
 void VPWidenEVLRecipe::execute(VPTransformState &State) {
   unsigned Opcode = getOpcode();
   // TODO: Support other opcodes
+  if (Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) {
+    Value *Op1 = State.get(getOperand(0), 0);
+    Value *Op2 = State.get(getOperand(1), 0);
+    auto &Ctx = State.Builder.getContext();
+    Value *Pred = MetadataAsValue::get(
+        Ctx, MDString::get(Ctx, CmpInst::getPredicateName(getPredicate())));
+
+    IRBuilderBase &BuilderIR = State.Builder;
+    VectorBuilder Builder(BuilderIR);
+    Value *Mask = BuilderIR.CreateVectorSplat(State.VF, BuilderIR.getTrue());
+    Builder.setMask(Mask).setEVL(State.get(getEVL(), /*NeedsScalar=*/true));
+
+    VectorType *DataType = VectorType::get(Type::getInt1Ty(Ctx), State.VF);
+
+    Value *VPInst = Builder.createVectorInstruction(Opcode, DataType,
+                                                    {Op1, Op2, Pred}, "vp.op");
+    //  if (isa<FPMathOperator>(VPInst))
+    // setFlags(cast<Instruction>(VPInst));
+    if (VPInst) {
----------------
artagnon wrote:

Unnecessary check?

https://github.com/llvm/llvm-project/pull/108533