[llvm] [RISCV][GISEL] Add support for lowerFormalArguments that contain scalable vector types (PR #70882)

[Michael Maitland via llvm-commits]

================
@@ -303,6 +309,11 @@ static bool isSupportedArgumentType(Type *T, const RISCVSubtarget &Subtarget) {
     return true;
   if (T->isPointerTy())
     return true;
+  // TODO: support 16bit FPtypes.
+  // TODO: Support fixed vector types.
+  if (IsLowerArgs && T->isVectorTy() && Subtarget.hasVInstructions() &&
+      !T->is16bitFPTy() && T->isScalableTy())
----------------
michaelmaitland wrote:

You make a good point. I think it may make sense to support for these kinds of types (including 16bitfp) in this patch.

https://github.com/llvm/llvm-project/pull/70882