[llvm] [AArch64][SME] Enable dynamic shuffle for fixed length types. (PR #72490)

[Sander de Smalen via llvm-commits]

================
@@ -26171,13 +26196,29 @@ static SDValue GenerateFixedLengthSVETBL(SDValue Op, SDValue Op1, SDValue Op2,
         DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, ContainerVT,
                     DAG.getConstant(Intrinsic::aarch64_sve_tbl, DL, MVT::i32),
                     Op1, SVEMask);
-  else if (Subtarget.hasSVE2())
+  else if (Subtarget.hasSVE2()) {
+    if (!MinMaxEqual) {
+      SDValue VScale =
+          (BitsPerElt == 64)
+              ? DAG.getVScale(DL, MVT::i64, APInt(64, 128 / BitsPerElt))
+              : DAG.getVScale(DL, MVT::i32, APInt(32, 128 / BitsPerElt));
----------------
sdesmalen-arm wrote:

```suggestion
      unsigned MinNumElts = AArch64::SVEBitsPerBlock / BitsPerElt;
      SDValue VScale =
          BitsPerElt == 64
              ? DAG.getVScale(DL, MVT::i64, APInt(64, MinNumElts))
              : DAG.getVScale(DL, MVT::i32, APInt(32, MinNumElts));
```

https://github.com/llvm/llvm-project/pull/72490