[llvm] 540fd18 - DAG: Avoid using getLibcallName when looking for a divrem call (#170413)

[via llvm-commits]

Author: Matt Arsenault
Date: 2025-12-03T13:01:21-05:00
New Revision: 540fd18568deb299a35b009d34ce32f96e3944bd

URL: https://github.com/llvm/llvm-project/commit/540fd18568deb299a35b009d34ce32f96e3944bd
DIFF: https://github.com/llvm/llvm-project/commit/540fd18568deb299a35b009d34ce32f96e3944bd.diff

LOG: DAG: Avoid using getLibcallName when looking for a divrem call (#170413)

Also introduce an error if it's not available, which is not yet
testable.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 99d14a60c6ed1..8336e1d1f4134 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2381,8 +2381,19 @@ SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
   Entry.IsZExt = !isSigned;
   Args.push_back(Entry);
 
-  SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
-                                         TLI.getPointerTy(DAG.getDataLayout()));
+  RTLIB::LibcallImpl LibcallImpl = TLI.getLibcallImpl(LC);
+  if (LibcallImpl == RTLIB::Unsupported) {
+    DAG.getContext()->emitError(Twine("no libcall available for ") +
+                                Node->getOperationName(&DAG));
+    SDValue Poison = DAG.getPOISON(RetVT);
+    Results.push_back(Poison);
+    Results.push_back(Poison);
+    return;
+  }
+
+  SDValue Callee =
+      DAG.getExternalSymbol(TLI.getLibcallImplName(LibcallImpl).data(),
+                            TLI.getPointerTy(DAG.getDataLayout()));
 
   SDLoc dl(Node);
   TargetLowering::CallLoweringInfo CLI(DAG);