[llvm] [clang] [AArch64][SME] Remove immediate argument restriction for svldr and svstr (PR #68565)

[Sander de Smalen via cfe-commits]

================
@@ -1744,45 +1744,60 @@ void AArch64DAGToDAGISel::SelectCVTIntrinsic(SDNode *N, unsigned NumVecs,
 
 void AArch64DAGToDAGISel::SelectSMELdrStrZA(SDNode *N, bool IsLoad) {
   // Lower an SME LDR/STR ZA intrinsic to LDR_ZA_PSEUDO or STR_ZA.
-  // If the vector select parameter is an immediate in the range 0-15 then we
-  // can emit it directly into the instruction as it's a legal operand.
-  // Otherwise we must emit 0 as the vector select operand and modify the base
-  // register instead.
+  // If the vector number is an immediate between 0 and 15 inclusive then we can
+  // put that directly into the immediate field of the instruction. If it's
+  // outside of that range then we modify the base and slice by the greatest
+  // multiple of 15 smaller than that number and put the remainder in the
+  // instruction field. If it's not an immediate then we modify the base and
+  // slice registers by that number and put 0 in the instruction.
   SDLoc DL(N);
 
-  SDValue VecNum = N->getOperand(4), Base = N->getOperand(3),
-          TileSlice = N->getOperand(2);
-  int Imm = -1;
-  if (auto ImmNode = dyn_cast<ConstantSDNode>(VecNum))
-    Imm = ImmNode->getZExtValue();
+  SDValue TileSlice = N->getOperand(2);
+  SDValue Base = N->getOperand(3);
+  SDValue VecNum = N->getOperand(4);
+  SDValue Remainder = CurDAG->getTargetConstant(0, DL, MVT::i32);
+
+  // true if the base and slice registers need to me modified
----------------
sdesmalen-arm wrote:

```suggestion
  // true if the base and slice registers need to be modified
```

https://github.com/llvm/llvm-project/pull/68565