[llvm] [LV][EVL] Support cast instruction with EVL-vectorization (PR #108351)

[Mel Chen via llvm-commits]

================
@@ -962,22 +962,35 @@ void VPWidenIntrinsicRecipe::execute(VPTransformState &State) {
 
   // Use vector version of the intrinsic.
   Module *M = State.Builder.GetInsertBlock()->getModule();
+  bool IsVPIntrinsic = VPIntrinsic::isVPIntrinsic(VectorIntrinsicID);
   Function *VectorF =
-      Intrinsic::getOrInsertDeclaration(M, VectorIntrinsicID, TysForDecl);
-  assert(VectorF && "Can't retrieve vector intrinsic.");
+      IsVPIntrinsic
+          ? VPIntrinsic::getOrInsertDeclarationForParams(M, VectorIntrinsicID,
+                                                         TysForDecl[0], Args)
+          : Intrinsic::getOrInsertDeclaration(M, VectorIntrinsicID, TysForDecl);
+  assert(VectorF &&
+         "Can't retrieve vector intrinsic or vector-predication intrinsics.");
 
-  auto *CI = cast_or_null<CallInst>(getUnderlyingValue());
   SmallVector<OperandBundleDef, 1> OpBundles;
-  if (CI)
-    CI->getOperandBundlesAsDefs(OpBundles);
+  if (!IsVPIntrinsic) {
+    if (auto *CI = cast_or_null<CallInst>(getUnderlyingValue()))
+      CI->getOperandBundlesAsDefs(OpBundles);
+  }
 
-  CallInst *V = State.Builder.CreateCall(VectorF, Args, OpBundles);
+  Instruction *V = State.Builder.CreateCall(VectorF, Args, OpBundles);
 
-  setFlags(V);
+  if (IsVPIntrinsic) {
+    // Currently vp-intrinsics only accept FMF flags. llvm.vp.uitofp will get
+    // Flags of OperationType::NonNegOp && OperationType::FPMathOp.
+    if (isa<FPMathOperator>(V) && VectorIntrinsicID != Intrinsic::vp_uitofp)
+      setFlags(V);
----------------
Mel-Chen wrote:

I have a question here.
Will setFlags really function as we expect if we don't pass the underlying instruction into the recipe? This PR also seems to lack corresponding test cases to verify whether the FMF has been correctly set.

https://github.com/llvm/llvm-project/pull/108351