[llvm] [SDAG] Merge multiple-result libcall expansion into DAG.expandMultipleResultFPLibCall() (PR #114792)

[Benjamin Maxwell via llvm-commits]

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@@ -1595,8 +1596,14 @@ class SelectionDAG {
   SDValue getPartialReduceAdd(SDLoc DL, EVT ReducedTy, SDValue Op1,
                               SDValue Op2);
 
-  /// Expand the specified \c ISD::FSINCOS node as the Legalize pass would.
-  bool expandFSINCOS(SDNode *Node, SmallVectorImpl<SDValue> &Results);
+  /// Expands a node with multiple results to an FP or vector libcall. The
+  /// libcall is expected to take all the operands of the \p Node followed by
+  /// output pointers for each of the results. \p CallRetResNo can be optionally
+  /// set to indicate that one of the results comes from the libcall's return
+  /// value.
+  bool expandMultipleResultFPLibCall(RTLIB::Libcall LC, SDNode *Node,
+                                     SmallVectorImpl<SDValue> &Results,
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MacDue wrote:

The results are not pointers they are the new values for the expanded node. E.g. for `FSINCOS` they're `sin(x)` and `cos(x)`.

https://github.com/llvm/llvm-project/pull/114792