Index: mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
===================================================================
--- mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
+++ mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
@@ -478,15 +478,14 @@
     if (!type)
       return nullptr;
     if (auto symbolRef = attr.dyn_cast<FlatSymbolRefAttr>())
-      return instMap[c] = bEntry.create<AddressOfOp>(unknownLoc, type,
-                                                     symbolRef.getValue());
-    return instMap[c] = bEntry.create<ConstantOp>(unknownLoc, type, attr);
+      return bEntry.create<AddressOfOp>(unknownLoc, type, symbolRef.getValue());
+    return bEntry.create<ConstantOp>(unknownLoc, type, attr);
   }
   if (auto *cn = dyn_cast<llvm::ConstantPointerNull>(c)) {
     Type type = processType(cn->getType());
     if (!type)
       return nullptr;
-    return instMap[c] = bEntry.create<NullOp>(unknownLoc, type);
+    return bEntry.create<NullOp>(unknownLoc, type);
   }
   if (auto *gv = dyn_cast<llvm::GlobalVariable>(c))
     return bEntry.create<AddressOfOp>(UnknownLoc::get(context),
@@ -510,13 +509,13 @@
     // falsely believe that the new Instruction has been processed before
     // and raised an assertion error.
     cleanupValues.insert(i);
-    return instMap[c] = instMap[i];
+    return instMap[i];
   }
   if (auto *ue = dyn_cast<llvm::UndefValue>(c)) {
     Type type = processType(ue->getType());
     if (!type)
       return nullptr;
-    return instMap[c] = bEntry.create<UndefOp>(UnknownLoc::get(context), type);
+    return bEntry.create<UndefOp>(UnknownLoc::get(context), type);
   }
 
   if (isa<llvm::ConstantAggregate>(c) || isa<llvm::ConstantAggregateZero>(c)) {
Index: mlir/test/Target/LLVMIR/Import/incorrect-constant-caching.ll
===================================================================
--- /dev/null
+++ mlir/test/Target/LLVMIR/Import/incorrect-constant-caching.ll
@@ -0,0 +1,27 @@
+; RUN: mlir-translate --import-llvm %s | FileCheck %s
+
+%my_struct = type {i32, i8*}
+; CHECK: llvm.mlir.constant(0 : i32) : i32
+; CHECK: llvm.mlir.constant(0 : i32) : i32
+; CHECK: llvm.mlir.addressof @str1 : !llvm.ptr<array<5 x i8>>
+; CHECK: llvm.getelementptr
+; CHECK: llvm.mlir.constant(7 : i32) : i32
+; CHECK: llvm.mlir.undef : !llvm.struct<"my_struct", (i32, ptr<i8>)>
+; CHECK: llvm.insertvalue
+; CHECK: llvm.insertvalue
+; CHECK: llvm.mlir.constant(0 : i32) : i32
+; CHECK: llvm.mlir.constant(0 : i32) : i32
+; CHECK: llvm.mlir.addressof @str0 : !llvm.ptr<array<5 x i8>>
+; CHECK: llvm.getelementptr
+; CHECK: llvm.mlir.constant(8 : i32) : i32
+; CHECK: llvm.mlir.undef : !llvm.struct<"my_struct", (i32, ptr<i8>)>
+; CHECK: llvm.insertvalue
+; CHECK: llvm.insertvalue
+; CHECK: llvm.mlir.undef : !llvm.array<2 x struct<"my_struct", (i32, ptr<i8>)>>
+; CHECK: llvm.insertvalue
+; CHECK: llvm.insertvalue
+; CHECK: llvm.return
+@str0 = private unnamed_addr constant [5 x i8] c"aaaa\00"
+@str1 = private unnamed_addr constant [5 x i8] c"bbbb\00"
+@g = global [2 x %my_struct] [%my_struct {i32 8, i8* getelementptr ([5 x i8], [5 x i8]* @str0, i32 0, i32 0)}, %my_struct {i32 7, i8* getelementptr ([5 x i8], [5 x i8]* @str1, i32 0, i32 0)}]
+