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

[Sander de Smalen via llvm-commits]

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@@ -2506,78 +2505,114 @@ bool SelectionDAG::expandFSINCOS(SDNode *Node,
     return nullptr;
   };
 
+  // For vector types, we must find a vector mapping for the libcall.
   VecDesc const *VD = nullptr;
   if (VT.isVector() && !(VD = getVecDesc()))
     return false;
 
   // Find users of the node that store the results (and share input chains). The
   // destination pointers can be used instead of creating stack allocations.
   SDValue StoresInChain{};
-  std::array<StoreSDNode *, 2> ResultStores = {nullptr};
+  SmallVector<StoreSDNode *, 2> ResultStores(NumResults);
   for (SDNode *User : Node->uses()) {
     if (!ISD::isNormalStore(User))
       continue;
     auto *ST = cast<StoreSDNode>(User);
-    if (!ST->isSimple() || ST->getAddressSpace() != 0 ||
-        ST->getAlign() < getDataLayout().getABITypeAlign(Ty->getScalarType()) ||
+    SDValue StoreValue = ST->getValue();
+    unsigned ResNo = StoreValue.getResNo();
+    Type *StoreType = StoreValue.getValueType().getTypeForEVT(Ctx);
+    if (CallRetResNo == ResNo || !ST->isSimple() ||
+        ST->getAddressSpace() != 0 ||
+        ST->getAlign() <
+            getDataLayout().getABITypeAlign(StoreType->getScalarType()) ||
         (StoresInChain && ST->getChain() != StoresInChain) ||
         Node->isPredecessorOf(ST->getChain().getNode()))
       continue;
-    ResultStores[ST->getValue().getResNo()] = ST;
+    ResultStores[ResNo] = ST;
     StoresInChain = ST->getChain();
   }
 
   TargetLowering::ArgListTy Args;
   TargetLowering::ArgListEntry Entry{};
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sdesmalen-arm wrote:

nit: could you make Entry local to the loops where they are used, that avoids fields being set and reused unintentionally.

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