DAG: Stop using TargetLibraryInfo for multi-result FP intrinsic codegen (llvm#166987)

Only use RuntimeLibcallsInfo. Remove the helper functions used to
transition.

Author: arsenm

llvm/include/llvm/CodeGen/SelectionDAG.h

@@ -1725,17 +1725,9 @@ class SelectionDAG {
   /// value.
   LLVM_ABI bool
   expandMultipleResultFPLibCall(RTLIB::Libcall LC, SDNode *Node,
-                                SmallVectorImpl<SDValue> &Results, EVT CallType,
+                                SmallVectorImpl<SDValue> &Results,
                                 std::optional<unsigned> CallRetResNo = {});
 
-  // FIXME: Ths should be removed, and form using RTLIB::Libcall should be
-  // preferred. Callers should resolve the exact type libcall to use.
-  LLVM_ABI bool
-  expandMultipleResultFPLibCall(StringRef LibcallName, CallingConv::ID CC,
-                                SDNode *Node, SmallVectorImpl<SDValue> &Results,
-                                std::optional<unsigned> CallRetResNo = {},
-                                bool IsVectorMasked = false);
-
   /// Expand the specified \c ISD::VAARG node as the Legalize pass would.
   LLVM_ABI SDValue expandVAArg(SDNode *Node);
 

llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

@@ -4842,7 +4842,7 @@ void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
     RTLIB::Libcall LC = Node->getOpcode() == ISD::FSINCOS
                             ? RTLIB::getSINCOS(VT)
                             : RTLIB::getSINCOSPI(VT);
-    bool Expanded = DAG.expandMultipleResultFPLibCall(LC, Node, Results, VT);
+    bool Expanded = DAG.expandMultipleResultFPLibCall(LC, Node, Results);
     if (!Expanded) {
       DAG.getContext()->emitError(Twine("no libcall available for ") +
                                   Node->getOperationName(&DAG));
@@ -4940,7 +4940,7 @@ void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
     EVT VT = Node->getValueType(0);
     RTLIB::Libcall LC = Node->getOpcode() == ISD::FMODF ? RTLIB::getMODF(VT)
                                                         : RTLIB::getFREXP(VT);
-    bool Expanded = DAG.expandMultipleResultFPLibCall(LC, Node, Results, VT,
+    bool Expanded = DAG.expandMultipleResultFPLibCall(LC, Node, Results,
                                                       /*CallRetResNo=*/0);
     if (!Expanded)
       llvm_unreachable("Expected scalar FFREXP/FMODF to expand to libcall!");

llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp

@@ -1726,8 +1726,7 @@ void DAGTypeLegalizer::ExpandFloatRes_UnaryWithTwoFPResults(
     SDNode *N, RTLIB::Libcall LC, std::optional<unsigned> CallRetResNo) {
   assert(!N->isStrictFPOpcode() && "strictfp not implemented");
   SmallVector<SDValue> Results;
-  DAG.expandMultipleResultFPLibCall(LC, N, Results, N->getValueType(0),
-                                    CallRetResNo);
+  DAG.expandMultipleResultFPLibCall(LC, N, Results, CallRetResNo);
   for (auto [ResNo, Res] : enumerate(Results)) {
     SDValue Lo, Hi;
     GetPairElements(Res, Lo, Hi);

llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp

@@ -1275,7 +1275,7 @@ void VectorLegalizer::Expand(SDNode *Node, SmallVectorImpl<SDValue> &Results) {
                             ? RTLIB::getSINCOS(VT)
                             : RTLIB::getSINCOSPI(VT);
     if (LC != RTLIB::UNKNOWN_LIBCALL &&
-        DAG.expandMultipleResultFPLibCall(LC, Node, Results, VT))
+        DAG.expandMultipleResultFPLibCall(LC, Node, Results))
       return;
 
     // TODO: Try to see if there's a narrower call available to use before
@@ -1286,7 +1286,7 @@ void VectorLegalizer::Expand(SDNode *Node, SmallVectorImpl<SDValue> &Results) {
     EVT VT = Node->getValueType(0);
     RTLIB::Libcall LC = RTLIB::getMODF(VT);
     if (LC != RTLIB::UNKNOWN_LIBCALL &&
-        DAG.expandMultipleResultFPLibCall(LC, Node, Results, VT,
+        DAG.expandMultipleResultFPLibCall(LC, Node, Results,
                                           /*CallRetResNo=*/0))
       return;
     break;

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -2514,56 +2514,14 @@ static bool canFoldStoreIntoLibCallOutputPointers(StoreSDNode *StoreNode,
 
 bool SelectionDAG::expandMultipleResultFPLibCall(
     RTLIB::Libcall LC, SDNode *Node, SmallVectorImpl<SDValue> &Results,
-    EVT CallVT, std::optional<unsigned> CallRetResNo) {
+    std::optional<unsigned> CallRetResNo) {
   if (LC == RTLIB::UNKNOWN_LIBCALL)
     return false;
 
-  EVT VT = Node->getValueType(0);
-
-  RTLIB::LibcallImpl Impl = TLI->getLibcallImpl(LC);
-  if (Impl == RTLIB::Unsupported)
-    return false;
-
-  StringRef LCName = TLI->getLibcallImplName(Impl);
-
-  // FIXME: This should not use TargetLibraryInfo. There should be
-  // RTLIB::Libcall entries for each used vector type, and directly matched.
-  auto getVecDesc = [&]() -> VecDesc const * {
-    for (bool Masked : {false, true}) {
-      if (VecDesc const *VD = getLibInfo().getVectorMappingInfo(
-              LCName, VT.getVectorElementCount(), Masked)) {
-        return VD;
-      }
-    }
-    return nullptr;
-  };
-
-  // For vector types, we must find a vector mapping for the libcall.
-  VecDesc const *VD = nullptr;
-  if (VT.isVector() && !CallVT.isVector() && !(VD = getVecDesc()))
+  RTLIB::LibcallImpl LibcallImpl = TLI->getLibcallImpl(LC);
+  if (LibcallImpl == RTLIB::Unsupported)
     return false;
 
-  bool IsMasked = (VD && VD->isMasked()) ||
-                  RTLIB::RuntimeLibcallsInfo::hasVectorMaskArgument(Impl);
-
-  // This wrapper function exists because getVectorMappingInfo works in terms of
-  // function names instead of RTLIB enums.
-
-  // FIXME: If we used a vector mapping, this assumes the calling convention of
-  // the vector function is the same as the scalar.
-
-  StringRef Name = VD ? VD->getVectorFnName() : LCName;
-
-  return expandMultipleResultFPLibCall(Name,
-                                       TLI->getLibcallImplCallingConv(Impl),
-                                       Node, Results, CallRetResNo, IsMasked);
-}
-
-// FIXME: This belongs in TargetLowering
-bool SelectionDAG::expandMultipleResultFPLibCall(
-    StringRef Name, CallingConv::ID CC, SDNode *Node,
-    SmallVectorImpl<SDValue> &Results, std::optional<unsigned> CallRetResNo,
-    bool IsMasked) {
   LLVMContext &Ctx = *getContext();
   EVT VT = Node->getValueType(0);
   unsigned NumResults = Node->getNumValues();
@@ -2624,8 +2582,8 @@ bool SelectionDAG::expandMultipleResultFPLibCall(
 
   SDLoc DL(Node);
 
-  // Pass the vector mask (if required).
-  if (IsMasked) {
+  if (RTLIB::RuntimeLibcallsInfo::hasVectorMaskArgument(LibcallImpl)) {
+    // Pass the vector mask (if required).
     EVT MaskVT = TLI->getSetCCResultType(getDataLayout(), Ctx, VT);
     SDValue Mask = getBoolConstant(true, DL, MaskVT, VT);
     Args.emplace_back(Mask, MaskVT.getTypeForEVT(Ctx));
@@ -2636,10 +2594,12 @@ bool SelectionDAG::expandMultipleResultFPLibCall(
                       : Type::getVoidTy(Ctx);
   SDValue InChain = StoresInChain ? StoresInChain : getEntryNode();
   SDValue Callee =
-      getExternalSymbol(Name.data(), TLI->getPointerTy(getDataLayout()));
+      getExternalSymbol(TLI->getLibcallImplName(LibcallImpl).data(),
+                        TLI->getPointerTy(getDataLayout()));
   TargetLowering::CallLoweringInfo CLI(*this);
-  CLI.setDebugLoc(DL).setChain(InChain).setLibCallee(CC, RetType, Callee,
-                                                     std::move(Args));
+  CLI.setDebugLoc(DL).setChain(InChain).setLibCallee(
+      TLI->getLibcallImplCallingConv(LibcallImpl), RetType, Callee,
+      std::move(Args));
 
   auto [Call, CallChain] = TLI->LowerCallTo(CLI);