[clang] [llvm] Adding splitdouble HLSL function (PR #109331)

[Farzon Lotfi via llvm-commits]

================
@@ -18957,6 +18957,134 @@ case Builtin::BI__builtin_hlsl_elementwise_isinf: {
         CGM.getHLSLRuntime().getRadiansIntrinsic(), ArrayRef<Value *>{Op0},
         nullptr, "hlsl.radians");
   }
+  case Builtin::BI__builtin_hlsl_splitdouble: {
+
+    assert((E->getArg(0)->getType()->hasFloatingRepresentation() &&
+            E->getArg(1)->getType()->hasUnsignedIntegerRepresentation() &&
+            E->getArg(2)->getType()->hasUnsignedIntegerRepresentation()) &&
+           "asuint operands types mismatch");
+    Value *Op0 = EmitScalarExpr(E->getArg(0));
+    const auto *OutArg1 = dyn_cast<HLSLOutArgExpr>(E->getArg(1));
+    const auto *OutArg2 = dyn_cast<HLSLOutArgExpr>(E->getArg(2));
+
+    CallArgList Args;
+    auto [Op1BaseLValue, Op1TmpLValue] =
----------------
farzonl wrote:

I don't see `Op1BaseLValue` or `Op2BaseLValue` used? I see you changed the return value of `EmitHLSLOutArgExpr` to be a pair from void. Should it still be a pair return value?

https://github.com/llvm/llvm-project/pull/109331