[clang] [llvm] [RISCV] Inline Assembly Support for GPR Pairs ('Pr') (PR #112983)

[Pengcheng Wang via cfe-commits]

================
@@ -21351,6 +21372,17 @@ bool RISCVTargetLowering::splitValueIntoRegisterParts(
     unsigned NumParts, MVT PartVT, std::optional<CallingConv::ID> CC) const {
   bool IsABIRegCopy = CC.has_value();
   EVT ValueVT = Val.getValueType();
+
+  if (ValueVT == (Subtarget.is64Bit() ? MVT::i128 : MVT::i64) &&
+      NumParts == 1 && PartVT == MVT::Untyped) {
+    // Pairs in Inline Assembly
+    MVT XLenVT = Subtarget.getXLenVT();
+    SDValue Lo, Hi;
+    std::tie(Lo, Hi) = DAG.SplitScalar(Val, DL, XLenVT, XLenVT);
----------------
wangpc-pp wrote:

```suggestion
    auto [Lo, Hi] = DAG.SplitScalar(Val, DL, XLenVT, XLenVT);
```

https://github.com/llvm/llvm-project/pull/112983