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

[Florian Hahn via llvm-commits]

================
@@ -1140,6 +1144,54 @@ void VPWidenRecipe::execute(VPTransformState &State) {
 #endif
 }
 
+void VPWidenEVLRecipe::execute(VPTransformState &State) {
+  State.setDebugLocFrom(getDebugLoc());
+  assert(State.UF == 1 && "Expected only UF == 1 when vectorizing with "
+                          "explicit vector length.");
+  VPValue *Op0 = getOperand(0);
+
+  assert(State.get(Op0, 0)->getType()->isVectorTy() &&
+         "VPWidenEVLRecipe should not be used for scalars");
+
+  VPValue *EVL = getEVL();
+  Value *EVLArg = State.get(EVL, 0, /*NeedsScalar=*/true);
+  unsigned Opcode = getOpcode();
+  Instruction *I = getUnderlyingInstr();
+  IRBuilderBase &BuilderIR = State.Builder;
+  VectorBuilder Builder(BuilderIR);
+  Value *Mask = BuilderIR.CreateVectorSplat(State.VF, BuilderIR.getTrue());
+  Value *VPInst = nullptr;
+
+  //===------------------- Binary and Unary Ops ---------------------===//
+  if (Instruction::isBinaryOp(Opcode) || Instruction::isUnaryOp(Opcode)) {
+    // Just widen unops and binops.
+
+    SmallVector<Value *, 4> Ops;
+    for (unsigned I = 0, E = getNumOperands() - 1; I < E; ++I) {
+      VPValue *VPOp = getOperand(I);
+      Ops.push_back(State.get(VPOp, 0));
+    }
+
+    Builder.setMask(Mask).setEVL(EVLArg);
+    VPInst = Builder.createVectorInstruction(Opcode, Ops[0]->getType(), Ops,
+                                             "vp.op");
+
+    if (auto *VecOp = dyn_cast_or_null<Instruction>(VPInst))
+      VecOp->copyIRFlags(I);
+  } else {
+    llvm_unreachable("Unsupported opcode in VPWidenEVLRecipe::execute");
+  }
+  State.set(this, VPInst, 0);
+  State.addMetadata(VPInst, I);
+}
+
+bool VPWidenEVLRecipe::onlyFirstLaneUsed(const VPValue *Op) const {
+  assert(is_contained(operands(), Op) && "Op must be an operand of the recipe");
----------------
fhahn wrote:

now that this is quite compact, maybe better to move to header again, consistent with other `onlyFirstLaneUsed` implementations?

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