diff --git a/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp b/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
--- a/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
+++ b/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
@@ -2278,11 +2278,11 @@
     auto targetStructType = typeConverter.convertType(memRefCastOp.getType());
     auto loc = op->getLoc();
 
-    // MemRefCastOp reduce to bitcast in the ranked MemRef case.
-    if (srcType.isa<MemRefType>() && dstType.isa<MemRefType>()) {
-      rewriter.replaceOpWithNewOp<LLVM::BitcastOp>(op, targetStructType,
-                                                   transformed.source());
-    } else if (srcType.isa<MemRefType>() && dstType.isa<UnrankedMemRefType>()) {
+    // For ranked/ranked case, just keep the original descriptor.
+    if (srcType.isa<MemRefType>() && dstType.isa<MemRefType>())
+      return rewriter.replaceOp(op, {transformed.source()});
+
+    if (srcType.isa<MemRefType>() && dstType.isa<UnrankedMemRefType>()) {
       // Casting ranked to unranked memref type
       // Set the rank in the destination from the memref type
       // Allocate space on the stack and copy the src memref descriptor
diff --git a/mlir/test/Conversion/StandardToLLVM/convert-dynamic-memref-ops.mlir b/mlir/test/Conversion/StandardToLLVM/convert-dynamic-memref-ops.mlir
--- a/mlir/test/Conversion/StandardToLLVM/convert-dynamic-memref-ops.mlir
+++ b/mlir/test/Conversion/StandardToLLVM/convert-dynamic-memref-ops.mlir
@@ -324,49 +324,49 @@
 
 // CHECK-LABEL: func @memref_cast_static_to_dynamic
 func @memref_cast_static_to_dynamic(%static : memref<10x42xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %static : memref<10x42xf32> to memref<?x?xf32>
   return
 }
 
 // CHECK-LABEL: func @memref_cast_static_to_mixed
 func @memref_cast_static_to_mixed(%static : memref<10x42xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %static : memref<10x42xf32> to memref<?x42xf32>
   return
 }
 
 // CHECK-LABEL: func @memref_cast_dynamic_to_static
 func @memref_cast_dynamic_to_static(%dynamic : memref<?x?xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %dynamic : memref<?x?xf32> to memref<10x12xf32>
   return
 }
 
 // CHECK-LABEL: func @memref_cast_dynamic_to_mixed
 func @memref_cast_dynamic_to_mixed(%dynamic : memref<?x?xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %dynamic : memref<?x?xf32> to memref<?x12xf32>
   return
 }
 
 // CHECK-LABEL: func @memref_cast_mixed_to_dynamic
 func @memref_cast_mixed_to_dynamic(%mixed : memref<42x?xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %mixed : memref<42x?xf32> to memref<?x?xf32>
   return
 }
 
 // CHECK-LABEL: func @memref_cast_mixed_to_static
 func @memref_cast_mixed_to_static(%mixed : memref<42x?xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %mixed : memref<42x?xf32> to memref<42x1xf32>
   return
 }
 
 // CHECK-LABEL: func @memref_cast_mixed_to_mixed
 func @memref_cast_mixed_to_mixed(%mixed : memref<42x?xf32>) {
-// CHECK: llvm.bitcast %{{.*}} : !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)> to !llvm.struct<(ptr<float>, ptr<float>, i64, array<2 x i64>, array<2 x i64>)>
+// CHECK-NOT: llvm.bitcast
   %0 = memref_cast %mixed : memref<42x?xf32> to memref<?x1xf32>
   return
 }