diff --git a/libspu/dialect/pphlo/transforms/partial_sort_to_topk.cc b/libspu/dialect/pphlo/transforms/partial_sort_to_topk.cc
index 139f2650..8d10e7a5 100644
--- a/libspu/dialect/pphlo/transforms/partial_sort_to_topk.cc
+++ b/libspu/dialect/pphlo/transforms/partial_sort_to_topk.cc
@@ -172,8 +172,7 @@ struct SortConversion : public OpRewritePattern<SimpleSortOp> {
     }
 
     // rewrite all slices
-    for (const auto &use : uses) {
-      auto slice = mlir::dyn_cast<SliceOp>(use.getOwner());
+    for (auto &slice : slices_to_rewrite) {
       auto offset = slice.getStartIndices()[sort_dim] - start;
       llvm::SmallVector<int64_t> new_start(slice.getStartIndices().begin(),
                                            slice.getStartIndices().end());
diff --git a/libspu/mpc/aby3/oram.cc b/libspu/mpc/aby3/oram.cc
index 395a05ba..c668c745 100644
--- a/libspu/mpc/aby3/oram.cc
+++ b/libspu/mpc/aby3/oram.cc
@@ -48,7 +48,7 @@ NdArrayRef OramOneHotAA::proc(KernelEvalContext *ctx, const NdArrayRef &in,
     // generate aeskey for dpf
     auto [self_aes_keys, next_aes_keys] = oram::genAesKey(ctx, 1);
 
-    auto *octx = new oram::OramContext<el_t>(s);
+    auto octx = oram::OramContext<el_t>(s);
 
     for (int64_t j = 0; j < 3; j++) {
       // in round (rank - 1), as helper
@@ -64,16 +64,16 @@ NdArrayRef OramOneHotAA::proc(KernelEvalContext *ctx, const NdArrayRef &in,
         auto target_point = dpf_rank ? target_idxs_[0][0] ^ target_idxs_[0][1]
                                      : target_idxs_[0][0];
         // dpf gen
-        octx->genDpf(ctx, static_cast<oram::DpfGenCtrl>(j), aes_key,
-                     target_point);
+        octx.genDpf(ctx, static_cast<oram::DpfGenCtrl>(j), aes_key,
+                    target_point);
         // B2A
-        octx->onehotB2A(ctx, static_cast<oram::DpfGenCtrl>(j));
+        octx.onehotB2A(ctx, static_cast<oram::DpfGenCtrl>(j));
       }
     }
 
     pforeach(0, s, [&](int64_t k) {
       for (int64_t j = 0; j < 2; j++) {
-        out_[k][j] = octx->dpf_e[j][k];
+        out_[k][j] = octx.dpf_e[j][k];
       }
     });
   });
@@ -124,15 +124,16 @@ NdArrayRef OramOneHotAP::proc(KernelEvalContext *ctx, const NdArrayRef &in,
       comm->sendAsync<uint128_t>(dst_rank, {aes_key}, "aes_key");
       aes_key += comm->recv<uint128_t>(dst_rank, "aes_key")[0];
 
-      auto *octx = new oram::OramContext<el_t>(s);
+      auto octx = oram::OramContext<el_t>(s);
+
       // dpf gen
-      octx->genDpf(ctx, static_cast<oram::DpfGenCtrl>(1), aes_key,
-                   target_point_2pc_[0]);
+      octx.genDpf(ctx, static_cast<oram::DpfGenCtrl>(1), aes_key,
+                  target_point_2pc_[0]);
       // B2A
-      octx->onehotB2A(ctx, static_cast<oram::DpfGenCtrl>(1));
+      octx.onehotB2A(ctx, static_cast<oram::DpfGenCtrl>(1));
 
       int64_t j = comm->getRank() == 0 ? 1 : 0;
-      pforeach(0, s, [&](int64_t k) { out_[k] = octx->dpf_e[j][k]; });
+      pforeach(0, s, [&](int64_t k) { out_[k] = octx.dpf_e[j][k]; });
     }
   });
 
@@ -480,9 +481,9 @@ void OramContext<T>::genDpf(KernelEvalContext *ctx, DpfGenCtrl ctrl,
                             uint128_t aes_key, uint128_t target_point) {
   auto *comm = ctx->getState<Communicator>();
 
-  auto *odpf = new OramDpf(dpf_size_, yacl::crypto::SecureRandU128(), aes_key,
-                           static_cast<uint128_t>(target_point));
-  odpf->gen(ctx, ctrl);
+  auto odpf = OramDpf(dpf_size_, yacl::crypto::SecureRandU128(), aes_key,
+                      static_cast<uint128_t>(target_point));
+  odpf.gen(ctx, ctrl);
 
   auto dpf_rank = comm->getRank() == static_cast<size_t>(ctrl);
   int64_t dpf_idx = dpf_rank ? 0 : 1;
@@ -490,10 +491,10 @@ void OramContext<T>::genDpf(KernelEvalContext *ctx, DpfGenCtrl ctrl,
 
   // cast e and v to T type and convert v to arith
   // leave convert e outside
-  std::transform(odpf->final_e.begin(), odpf->final_e.begin() + dpf_size_,
+  std::transform(odpf.final_e.begin(), odpf.final_e.begin() + dpf_size_,
                  dpf_e[dpf_idx].begin(),
                  [&](uint8_t x) { return neg_flag * static_cast<T>(x); });
-  std::transform(odpf->final_v.begin(), odpf->final_v.begin() + dpf_size_,
+  std::transform(odpf.final_v.begin(), odpf.final_v.begin() + dpf_size_,
                  convert_help_v[dpf_idx].begin(),
                  [&](uint128_t x) { return neg_flag * static_cast<T>(x); });
 };