diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -7509,6 +7509,12 @@
     if (Op0->getOpcode() == RISCVISD::BuildPairF64)
       return DCI.CombineTo(N, Op0.getOperand(0), Op0.getOperand(1));
 
+    if (Op0->isUndef()) {
+      SDValue Lo = DAG.getUNDEF(MVT::i32);
+      SDValue Hi = DAG.getUNDEF(MVT::i32);
+      return DCI.CombineTo(N, Lo, Hi);
+    }
+
     SDLoc DL(N);
 
     // It's cheaper to materialise two 32-bit integers than to load a double
diff --git a/llvm/test/CodeGen/RISCV/calling-conv-ilp32d.ll b/llvm/test/CodeGen/RISCV/calling-conv-ilp32d.ll
--- a/llvm/test/CodeGen/RISCV/calling-conv-ilp32d.ll
+++ b/llvm/test/CodeGen/RISCV/calling-conv-ilp32d.ll
@@ -265,3 +265,10 @@
   %3 = trunc i64 %2 to i32
   ret i32 %3
 }
+
+define double @func_return_undef() {
+; RV32-ILP32D-LABEL: func_return_undef:
+; RV32-ILP32D:       # %bb.0:
+; RV32-ILP32D-NEXT:    ret
+  ret double undef
+}