diff --git a/compiler/dex/global_value_numbering.cc b/compiler/dex/global_value_numbering.cc
index d311bc7..dbe9850 100644
--- a/compiler/dex/global_value_numbering.cc
+++ b/compiler/dex/global_value_numbering.cc
@@ -15,7 +15,6 @@
  */
 
 #include "global_value_numbering.h"
-
 #include "local_value_numbering.h"
 
 namespace art {
@@ -31,8 +30,6 @@
       modifications_allowed_(true),
       mode_(mode),
       global_value_map_(std::less<uint64_t>(), allocator->Adapter()),
-      field_index_map_(FieldReferenceComparator(), allocator->Adapter()),
-      field_index_reverse_map_(allocator->Adapter()),
       array_location_map_(ArrayLocationComparator(), allocator->Adapter()),
       array_location_reverse_map_(allocator->Adapter()),
       ref_set_map_(std::less<ValueNameSet>(), allocator->Adapter()),
@@ -145,19 +142,6 @@
   return change;
 }
 
-uint16_t GlobalValueNumbering::GetFieldId(const MirFieldInfo& field_info, uint16_t type) {
-  FieldReference key = { field_info.DeclaringDexFile(), field_info.DeclaringFieldIndex(), type };
-  auto lb = field_index_map_.lower_bound(key);
-  if (lb != field_index_map_.end() && !field_index_map_.key_comp()(key, lb->first)) {
-    return lb->second;
-  }
-  DCHECK_LT(field_index_map_.size(), kNoValue);
-  uint16_t id = field_index_map_.size();
-  auto it = field_index_map_.PutBefore(lb, key, id);
-  field_index_reverse_map_.push_back(&*it);
-  return id;
-}
-
 uint16_t GlobalValueNumbering::GetArrayLocation(uint16_t base, uint16_t index) {
   auto cmp = array_location_map_.key_comp();
   ArrayLocation key = { base, index };
diff --git a/compiler/dex/global_value_numbering.h b/compiler/dex/global_value_numbering.h
index 72d1112..8a93afb 100644
--- a/compiler/dex/global_value_numbering.h
+++ b/compiler/dex/global_value_numbering.h
@@ -39,6 +39,12 @@
         cu->mir_graph->GetMaxNestedLoops() > kMaxAllowedNestedLoops;
   }
 
+  // Instance and static field id map is held by MIRGraph to avoid multiple recalculations
+  // when doing LVN.
+  template <typename Container>  // Container of MirIFieldLoweringInfo or MirSFieldLoweringInfo.
+  static uint16_t* PrepareGvnFieldIds(ScopedArenaAllocator* allocator,
+                                      const Container& field_infos);
+
   GlobalValueNumbering(CompilationUnit* cu, ScopedArenaAllocator* allocator, Mode mode);
   ~GlobalValueNumbering();
 
@@ -114,34 +120,24 @@
     return (it != global_value_map_.end() && it->second == value);
   }
 
-  // FieldReference represents a unique resolved field.
-  struct FieldReference {
-    const DexFile* dex_file;
-    uint16_t field_idx;
-    uint16_t type;  // See comments for LocalValueNumbering::kFieldTypeCount.
-  };
+  // Get an instance field id.
+  uint16_t GetIFieldId(MIR* mir) {
+    return GetMirGraph()->GetGvnIFieldId(mir);
+  }
 
-  struct FieldReferenceComparator {
-    bool operator()(const FieldReference& lhs, const FieldReference& rhs) const {
-      if (lhs.field_idx != rhs.field_idx) {
-        return lhs.field_idx < rhs.field_idx;
-      }
-      // If the field_idx and dex_file match, the type must also match.
-      DCHECK(lhs.dex_file != rhs.dex_file || lhs.type == rhs.type);
-      return lhs.dex_file < rhs.dex_file;
-    }
-  };
+  // Get a static field id.
+  uint16_t GetSFieldId(MIR* mir) {
+    return GetMirGraph()->GetGvnSFieldId(mir);
+  }
 
-  // Maps field key to field id for resolved fields.
-  typedef ScopedArenaSafeMap<FieldReference, uint32_t, FieldReferenceComparator> FieldIndexMap;
+  // Get an instance field type based on field id.
+  uint16_t GetIFieldType(uint16_t field_id) {
+    return static_cast<uint16_t>(GetMirGraph()->GetIFieldLoweringInfo(field_id).MemAccessType());
+  }
 
-  // Get a field id.
-  uint16_t GetFieldId(const MirFieldInfo& field_info, uint16_t type);
-
-  // Get a field type based on field id.
-  uint16_t GetFieldType(uint16_t field_id) {
-    DCHECK_LT(field_id, field_index_reverse_map_.size());
-    return field_index_reverse_map_[field_id]->first.type;
+  // Get a static field type based on field id.
+  uint16_t GetSFieldType(uint16_t field_id) {
+    return static_cast<uint16_t>(GetMirGraph()->GetSFieldLoweringInfo(field_id).MemAccessType());
   }
 
   struct ArrayLocation {
@@ -239,8 +235,6 @@
   Mode mode_;
 
   ValueMap global_value_map_;
-  FieldIndexMap field_index_map_;
-  ScopedArenaVector<const FieldIndexMap::value_type*> field_index_reverse_map_;
   ArrayLocationMap array_location_map_;
   ScopedArenaVector<const ArrayLocationMap::value_type*> array_location_reverse_map_;
   RefSetIdMap ref_set_map_;
@@ -268,6 +262,32 @@
   return last_value_;
 }
 
+template <typename Container>  // Container of MirIFieldLoweringInfo or MirSFieldLoweringInfo.
+uint16_t* GlobalValueNumbering::PrepareGvnFieldIds(ScopedArenaAllocator* allocator,
+                                                   const Container& field_infos) {
+  size_t size = field_infos.size();
+  uint16_t* field_ids = reinterpret_cast<uint16_t*>(allocator->Alloc(size * sizeof(uint16_t),
+                                                                     kArenaAllocMisc));
+  for (size_t i = 0u; i != size; ++i) {
+    size_t idx = i;
+    const MirFieldInfo& cur_info = field_infos[i];
+    if (cur_info.IsResolved()) {
+      for (size_t j = 0; j != i; ++j) {
+        const MirFieldInfo& prev_info = field_infos[j];
+        if (prev_info.IsResolved() &&
+            prev_info.DeclaringDexFile() == cur_info.DeclaringDexFile() &&
+            prev_info.DeclaringFieldIndex() == cur_info.DeclaringFieldIndex()) {
+          DCHECK_EQ(cur_info.MemAccessType(), prev_info.MemAccessType());
+          idx = j;
+          break;
+        }
+      }
+    }
+    field_ids[i] = idx;
+  }
+  return field_ids;
+}
+
 }  // namespace art
 
 #endif  // ART_COMPILER_DEX_GLOBAL_VALUE_NUMBERING_H_
diff --git a/compiler/dex/global_value_numbering_test.cc b/compiler/dex/global_value_numbering_test.cc
index 35d5b99..a788129 100644
--- a/compiler/dex/global_value_numbering_test.cc
+++ b/compiler/dex/global_value_numbering_test.cc
@@ -17,6 +17,7 @@
 #include "compiler_internals.h"
 #include "dataflow_iterator.h"
 #include "dataflow_iterator-inl.h"
+#include "dex/mir_field_info.h"
 #include "global_value_numbering.h"
 #include "local_value_numbering.h"
 #include "gtest/gtest.h"
@@ -32,6 +33,7 @@
     uintptr_t declaring_dex_file;
     uint16_t declaring_field_idx;
     bool is_volatile;
+    DexMemAccessType type;
   };
 
   struct SFieldDef {
@@ -39,6 +41,7 @@
     uintptr_t declaring_dex_file;
     uint16_t declaring_field_idx;
     bool is_volatile;
+    DexMemAccessType type;
   };
 
   struct BBDef {
@@ -137,12 +140,11 @@
     cu_.mir_graph->ifield_lowering_infos_.reserve(count);
     for (size_t i = 0u; i != count; ++i) {
       const IFieldDef* def = &defs[i];
-      MirIFieldLoweringInfo field_info(def->field_idx);
+      MirIFieldLoweringInfo field_info(def->field_idx, def->type);
       if (def->declaring_dex_file != 0u) {
         field_info.declaring_dex_file_ = reinterpret_cast<const DexFile*>(def->declaring_dex_file);
         field_info.declaring_field_idx_ = def->declaring_field_idx;
-        field_info.flags_ = 0u |  // Without kFlagIsStatic.
-            (def->is_volatile ? MirIFieldLoweringInfo::kFlagIsVolatile : 0u);
+        field_info.flags_ &= ~(def->is_volatile ? 0u : MirSFieldLoweringInfo::kFlagIsVolatile);
       }
       cu_.mir_graph->ifield_lowering_infos_.push_back(field_info);
     }
@@ -158,15 +160,14 @@
     cu_.mir_graph->sfield_lowering_infos_.reserve(count);
     for (size_t i = 0u; i != count; ++i) {
       const SFieldDef* def = &defs[i];
-      MirSFieldLoweringInfo field_info(def->field_idx);
+      MirSFieldLoweringInfo field_info(def->field_idx, def->type);
       // Mark even unresolved fields as initialized.
-      field_info.flags_ = MirSFieldLoweringInfo::kFlagIsStatic |
-          MirSFieldLoweringInfo::kFlagClassIsInitialized;
+      field_info.flags_ |= MirSFieldLoweringInfo::kFlagClassIsInitialized;
       // NOTE: MirSFieldLoweringInfo::kFlagClassIsInDexCache isn't used by GVN.
       if (def->declaring_dex_file != 0u) {
         field_info.declaring_dex_file_ = reinterpret_cast<const DexFile*>(def->declaring_dex_file);
         field_info.declaring_field_idx_ = def->declaring_field_idx;
-        field_info.flags_ |= (def->is_volatile ? MirSFieldLoweringInfo::kFlagIsVolatile : 0u);
+        field_info.flags_ &= ~(def->is_volatile ? 0u : MirSFieldLoweringInfo::kFlagIsVolatile);
       }
       cu_.mir_graph->sfield_lowering_infos_.push_back(field_info);
     }
@@ -238,12 +239,16 @@
       mir->dalvikInsn.opcode = def->opcode;
       mir->dalvikInsn.vB = static_cast<int32_t>(def->value);
       mir->dalvikInsn.vB_wide = def->value;
-      if (def->opcode >= Instruction::IGET && def->opcode <= Instruction::IPUT_SHORT) {
+      if (IsInstructionIGetOrIPut(def->opcode)) {
         ASSERT_LT(def->field_info, cu_.mir_graph->ifield_lowering_infos_.size());
         mir->meta.ifield_lowering_info = def->field_info;
-      } else if (def->opcode >= Instruction::SGET && def->opcode <= Instruction::SPUT_SHORT) {
+        ASSERT_EQ(cu_.mir_graph->ifield_lowering_infos_[def->field_info].MemAccessType(),
+                  IGetOrIPutMemAccessType(def->opcode));
+      } else if (IsInstructionSGetOrSPut(def->opcode)) {
         ASSERT_LT(def->field_info, cu_.mir_graph->sfield_lowering_infos_.size());
         mir->meta.sfield_lowering_info = def->field_info;
+        ASSERT_EQ(cu_.mir_graph->sfield_lowering_infos_[def->field_info].MemAccessType(),
+                  SGetOrSPutMemAccessType(def->opcode));
       } else if (def->opcode == static_cast<Instruction::Code>(kMirOpPhi)) {
         mir->meta.phi_incoming = static_cast<BasicBlockId*>(
             allocator_->Alloc(def->num_uses * sizeof(BasicBlockId), kArenaAllocDFInfo));
@@ -288,6 +293,10 @@
     cu_.mir_graph->ComputeDominators();
     cu_.mir_graph->ComputeTopologicalSortOrder();
     cu_.mir_graph->SSATransformationEnd();
+    cu_.mir_graph->temp_.gvn.ifield_ids_ =  GlobalValueNumbering::PrepareGvnFieldIds(
+        allocator_.get(), cu_.mir_graph->ifield_lowering_infos_);
+    cu_.mir_graph->temp_.gvn.sfield_ids_ =  GlobalValueNumbering::PrepareGvnFieldIds(
+        allocator_.get(), cu_.mir_graph->sfield_lowering_infos_);
     ASSERT_TRUE(gvn_ == nullptr);
     gvn_.reset(new (allocator_.get()) GlobalValueNumbering(&cu_, allocator_.get(),
                                                            GlobalValueNumbering::kModeGvn));
@@ -498,18 +507,18 @@
 
 TEST_F(GlobalValueNumberingTestDiamond, NonAliasingIFields) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Int.
-      { 4u, 1u, 4u, false },  // Short.
-      { 5u, 1u, 5u, false },  // Char.
-      { 6u, 0u, 0u, false },  // Unresolved, Short.
-      { 7u, 1u, 7u, false },  // Int.
-      { 8u, 0u, 0u, false },  // Unresolved, Int.
-      { 9u, 1u, 9u, false },  // Int.
-      { 10u, 1u, 10u, false },  // Int.
-      { 11u, 1u, 11u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
+      { 4u, 1u, 4u, false, kDexMemAccessShort },
+      { 5u, 1u, 5u, false, kDexMemAccessChar },
+      { 6u, 0u, 0u, false, kDexMemAccessShort },   // Unresolved.
+      { 7u, 1u, 7u, false, kDexMemAccessWord },
+      { 8u, 0u, 0u, false, kDexMemAccessWord },    // Unresolved.
+      { 9u, 1u, 9u, false, kDexMemAccessWord },
+      { 10u, 1u, 10u, false, kDexMemAccessWord },
+      { 11u, 1u, 11u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -604,15 +613,15 @@
 
 TEST_F(GlobalValueNumberingTestDiamond, AliasingIFieldsSingleObject) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Int.
-      { 4u, 1u, 4u, false },  // Short.
-      { 5u, 1u, 5u, false },  // Char.
-      { 6u, 0u, 0u, false },  // Unresolved, Short.
-      { 7u, 1u, 7u, false },  // Int.
-      { 8u, 1u, 8u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
+      { 4u, 1u, 4u, false, kDexMemAccessShort },
+      { 5u, 1u, 5u, false, kDexMemAccessChar },
+      { 6u, 0u, 0u, false, kDexMemAccessShort },  // Unresolved.
+      { 7u, 1u, 7u, false, kDexMemAccessWord },
+      { 8u, 1u, 8u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -671,15 +680,15 @@
 
 TEST_F(GlobalValueNumberingTestDiamond, AliasingIFieldsTwoObjects) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Int.
-      { 4u, 1u, 4u, false },  // Short.
-      { 5u, 1u, 5u, false },  // Char.
-      { 6u, 0u, 0u, false },  // Unresolved, Short.
-      { 7u, 1u, 7u, false },  // Int.
-      { 8u, 1u, 8u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
+      { 4u, 1u, 4u, false, kDexMemAccessShort },
+      { 5u, 1u, 5u, false, kDexMemAccessChar },
+      { 6u, 0u, 0u, false, kDexMemAccessShort },   // Unresolved.
+      { 7u, 1u, 7u, false, kDexMemAccessWord },
+      { 8u, 1u, 8u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -740,15 +749,15 @@
 
 TEST_F(GlobalValueNumberingTestDiamond, SFields) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Int.
-      { 4u, 1u, 4u, false },  // Short.
-      { 5u, 1u, 5u, false },  // Char.
-      { 6u, 0u, 0u, false },  // Unresolved, Short.
-      { 7u, 1u, 7u, false },  // Int.
-      { 8u, 1u, 8u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
+      { 4u, 1u, 4u, false, kDexMemAccessShort },
+      { 5u, 1u, 5u, false, kDexMemAccessChar },
+      { 6u, 0u, 0u, false, kDexMemAccessShort },   // Unresolved.
+      { 7u, 1u, 7u, false, kDexMemAccessWord },
+      { 8u, 1u, 8u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -1078,18 +1087,18 @@
 
 TEST_F(GlobalValueNumberingTestLoop, NonAliasingIFields) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Int.
-      { 4u, 1u, 4u, false },  // Int.
-      { 5u, 1u, 5u, false },  // Short.
-      { 6u, 1u, 6u, false },  // Char.
-      { 7u, 0u, 0u, false },  // Unresolved, Short.
-      { 8u, 1u, 8u, false },  // Int.
-      { 9u, 0u, 0u, false },  // Unresolved, Int.
-      { 10u, 1u, 10u, false },  // Int.
-      { 11u, 1u, 11u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
+      { 4u, 1u, 4u, false, kDexMemAccessWord },
+      { 5u, 1u, 5u, false, kDexMemAccessShort },
+      { 6u, 1u, 6u, false, kDexMemAccessChar },
+      { 7u, 0u, 0u, false, kDexMemAccessShort },   // Unresolved.
+      { 8u, 1u, 8u, false, kDexMemAccessWord },
+      { 9u, 0u, 0u, false, kDexMemAccessWord },    // Unresolved.
+      { 10u, 1u, 10u, false, kDexMemAccessWord },
+      { 11u, 1u, 11u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -1201,14 +1210,14 @@
 
 TEST_F(GlobalValueNumberingTestLoop, AliasingIFieldsSingleObject) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Int.
-      { 4u, 1u, 4u, false },  // Int.
-      { 5u, 1u, 5u, false },  // Short.
-      { 6u, 1u, 6u, false },  // Char.
-      { 7u, 0u, 0u, false },  // Unresolved, Short.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
+      { 4u, 1u, 4u, false, kDexMemAccessWord },
+      { 5u, 1u, 5u, false, kDexMemAccessShort },
+      { 6u, 1u, 6u, false, kDexMemAccessChar },
+      { 7u, 0u, 0u, false, kDexMemAccessShort },   // Unresolved.
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -1272,14 +1281,14 @@
 
 TEST_F(GlobalValueNumberingTestLoop, AliasingIFieldsTwoObjects) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
-      { 3u, 1u, 3u, false },  // Short.
-      { 4u, 1u, 4u, false },  // Char.
-      { 5u, 0u, 0u, false },  // Unresolved, Short.
-      { 6u, 1u, 6u, false },  // Int.
-      { 7u, 1u, 7u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
+      { 3u, 1u, 3u, false, kDexMemAccessShort },
+      { 4u, 1u, 4u, false, kDexMemAccessChar },
+      { 5u, 0u, 0u, false, kDexMemAccessShort },   // Unresolved.
+      { 6u, 1u, 6u, false, kDexMemAccessWord },
+      { 7u, 1u, 7u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -1341,7 +1350,7 @@
 
 TEST_F(GlobalValueNumberingTestLoop, IFieldToBaseDependency) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // For the IGET that loads sreg 3u using base 2u, the following IPUT creates a dependency
@@ -1366,9 +1375,9 @@
 
 TEST_F(GlobalValueNumberingTestLoop, SFields) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
-      { 2u, 1u, 2u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -1562,8 +1571,8 @@
 
 TEST_F(GlobalValueNumberingTestCatch, IFields) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },
-      { 1u, 1u, 1u, false },
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(3, Instruction::NEW_INSTANCE, 200u),
@@ -1608,8 +1617,8 @@
 
 TEST_F(GlobalValueNumberingTestCatch, SFields) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },
-      { 1u, 1u, 1u, false },
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_SGET(3, Instruction::SGET, 0u, 0u),
@@ -1731,8 +1740,8 @@
 
 TEST_F(GlobalValueNumberingTest, NullCheckIFields) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Object.
-      { 1u, 1u, 1u, false },  // Object.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },  // Object.
+      { 1u, 1u, 1u, false, kDexMemAccessObject },  // Object.
   };
   static const BBDef bbs[] = {
       DEF_BB(kNullBlock, DEF_SUCC0(), DEF_PRED0()),
@@ -1780,8 +1789,8 @@
 
 TEST_F(GlobalValueNumberingTest, NullCheckSFields) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },  // Object.
-      { 1u, 1u, 1u, false },  // Object.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
+      { 1u, 1u, 1u, false, kDexMemAccessObject },
   };
   static const BBDef bbs[] = {
       DEF_BB(kNullBlock, DEF_SUCC0(), DEF_PRED0()),
@@ -1907,12 +1916,12 @@
 
 TEST_F(GlobalValueNumberingTestDiamond, MergeSameValueInDifferentMemoryLocations) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },  // Int.
-      { 1u, 1u, 1u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessWord },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(3, Instruction::NEW_INSTANCE, 100u),
@@ -1977,7 +1986,7 @@
   // LVN's aliasing_array_value_map_'s load_value_map for BBs #9, #4, #5, #7 because of the
   // DFS ordering of LVN evaluation.
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Object.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
   };
   static const BBDef bbs[] = {
       DEF_BB(kNullBlock, DEF_SUCC0(), DEF_PRED0()),
@@ -2015,7 +2024,7 @@
 
 TEST_F(GlobalValueNumberingTestTwoConsecutiveLoops, IFieldAndPhi) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
   };
   static const MIRDef mirs[] = {
       DEF_MOVE(3, Instruction::MOVE_OBJECT, 0u, 100u),
@@ -2052,10 +2061,10 @@
 
 TEST_F(GlobalValueNumberingTestTwoConsecutiveLoops, NullCheck) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
   };
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
   };
   static const MIRDef mirs[] = {
       DEF_MOVE(3, Instruction::MOVE_OBJECT, 0u, 100u),
@@ -2143,7 +2152,7 @@
 
 TEST_F(GlobalValueNumberingTestTwoNestedLoops, IFieldAndPhi) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, false },  // Int.
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
   };
   static const MIRDef mirs[] = {
       DEF_MOVE(3, Instruction::MOVE_OBJECT, 0u, 100u),
diff --git a/compiler/dex/local_value_numbering.cc b/compiler/dex/local_value_numbering.cc
index c1ce2ac..90b91bc 100644
--- a/compiler/dex/local_value_numbering.cc
+++ b/compiler/dex/local_value_numbering.cc
@@ -56,7 +56,7 @@
  public:
   static uint16_t StartMemoryVersion(GlobalValueNumbering* gvn, const LocalValueNumbering* lvn,
                                      uint16_t field_id) {
-    uint16_t type = gvn->GetFieldType(field_id);
+    uint16_t type = gvn->GetIFieldType(field_id);
     return gvn->LookupValue(kAliasingIFieldStartVersionOp, field_id,
                             lvn->global_memory_version_, lvn->unresolved_ifield_version_[type]);
   }
@@ -75,7 +75,7 @@
   static uint16_t LookupMergeValue(GlobalValueNumbering* gvn, const LocalValueNumbering* lvn,
                                    uint16_t field_id, uint16_t base) {
     // If the base/field_id is non-aliasing in lvn, use the non-aliasing value.
-    uint16_t type = gvn->GetFieldType(field_id);
+    uint16_t type = gvn->GetIFieldType(field_id);
     if (lvn->IsNonAliasingIField(base, field_id, type)) {
       uint16_t loc = gvn->LookupValue(kNonAliasingIFieldLocOp, base, field_id, type);
       auto lb = lvn->non_aliasing_ifield_value_map_.find(loc);
@@ -89,7 +89,7 @@
 
   static bool HasNewBaseVersion(GlobalValueNumbering* gvn, const LocalValueNumbering* lvn,
                                 uint16_t field_id) {
-    uint16_t type = gvn->GetFieldType(field_id);
+    uint16_t type = gvn->GetIFieldType(field_id);
     return lvn->unresolved_ifield_version_[type] == lvn->merge_new_memory_version_ ||
         lvn->global_memory_version_ == lvn->merge_new_memory_version_;
   }
@@ -711,7 +711,7 @@
     if (it != lvn->sfield_value_map_.end()) {
       value_name = it->second;
     } else {
-      uint16_t type = gvn_->GetFieldType(field_id);
+      uint16_t type = gvn_->GetSFieldType(field_id);
       value_name = gvn_->LookupValue(kResolvedSFieldOp, field_id,
                                      lvn->unresolved_sfield_version_[type],
                                      lvn->global_memory_version_);
@@ -1150,12 +1150,11 @@
 }
 
 uint16_t LocalValueNumbering::HandleAGet(MIR* mir, uint16_t opcode) {
-  // uint16_t type = opcode - Instruction::AGET;
   uint16_t array = GetOperandValue(mir->ssa_rep->uses[0]);
   HandleNullCheck(mir, array);
   uint16_t index = GetOperandValue(mir->ssa_rep->uses[1]);
   HandleRangeCheck(mir, array, index);
-  uint16_t type = opcode - Instruction::AGET;
+  uint16_t type = AGetMemAccessType(static_cast<Instruction::Code>(opcode));
   // Establish value number for loaded register.
   uint16_t res;
   if (IsNonAliasingArray(array, type)) {
@@ -1182,7 +1181,7 @@
   uint16_t index = GetOperandValue(mir->ssa_rep->uses[index_idx]);
   HandleRangeCheck(mir, array, index);
 
-  uint16_t type = opcode - Instruction::APUT;
+  uint16_t type = APutMemAccessType(static_cast<Instruction::Code>(opcode));
   uint16_t value = (opcode == Instruction::APUT_WIDE)
                    ? GetOperandValueWide(mir->ssa_rep->uses[0])
                    : GetOperandValue(mir->ssa_rep->uses[0]);
@@ -1224,8 +1223,8 @@
     // Use result s_reg - will be unique.
     res = gvn_->LookupValue(kNoValue, mir->ssa_rep->defs[0], kNoValue, kNoValue);
   } else {
-    uint16_t type = opcode - Instruction::IGET;
-    uint16_t field_id = gvn_->GetFieldId(field_info, type);
+    uint16_t type = IGetMemAccessType(static_cast<Instruction::Code>(opcode));
+    uint16_t field_id = gvn_->GetIFieldId(mir);
     if (IsNonAliasingIField(base, field_id, type)) {
       uint16_t loc = gvn_->LookupValue(kNonAliasingIFieldLocOp, base, field_id, type);
       auto lb = non_aliasing_ifield_value_map_.lower_bound(loc);
@@ -1249,10 +1248,10 @@
 }
 
 void LocalValueNumbering::HandleIPut(MIR* mir, uint16_t opcode) {
-  uint16_t type = opcode - Instruction::IPUT;
   int base_reg = (opcode == Instruction::IPUT_WIDE) ? 2 : 1;
   uint16_t base = GetOperandValue(mir->ssa_rep->uses[base_reg]);
   HandleNullCheck(mir, base);
+  uint16_t type = IPutMemAccessType(static_cast<Instruction::Code>(opcode));
   const MirFieldInfo& field_info = gvn_->GetMirGraph()->GetIFieldLoweringInfo(mir);
   if (!field_info.IsResolved()) {
     // Unresolved fields always alias with everything of the same type.
@@ -1272,7 +1271,7 @@
     // Aliasing fields of the same type may have been overwritten.
     auto it = aliasing_ifield_value_map_.begin(), end = aliasing_ifield_value_map_.end();
     while (it != end) {
-      if (gvn_->GetFieldType(it->first) != type) {
+      if (gvn_->GetIFieldType(it->first) != type) {
         ++it;
       } else {
         it = aliasing_ifield_value_map_.erase(it);
@@ -1282,7 +1281,7 @@
     // Nothing to do, resolved volatile fields always get a new memory version anyway and
     // can't alias with resolved non-volatile fields.
   } else {
-    uint16_t field_id = gvn_->GetFieldId(field_info, type);
+    uint16_t field_id = gvn_->GetIFieldId(mir);
     uint16_t value = (opcode == Instruction::IPUT_WIDE)
                      ? GetOperandValueWide(mir->ssa_rep->uses[0])
                      : GetOperandValue(mir->ssa_rep->uses[0]);
@@ -1333,8 +1332,8 @@
     // Use result s_reg - will be unique.
     res = gvn_->LookupValue(kNoValue, mir->ssa_rep->defs[0], kNoValue, kNoValue);
   } else {
-    uint16_t type = opcode - Instruction::SGET;
-    uint16_t field_id = gvn_->GetFieldId(field_info, type);
+    uint16_t type = SGetMemAccessType(static_cast<Instruction::Code>(opcode));
+    uint16_t field_id = gvn_->GetSFieldId(mir);
     auto lb = sfield_value_map_.lower_bound(field_id);
     if (lb != sfield_value_map_.end() && lb->first == field_id) {
       res = lb->second;
@@ -1362,7 +1361,7 @@
     // Class initialization can call arbitrary functions, we need to wipe aliasing values.
     HandleInvokeOrClInitOrAcquireOp(mir);
   }
-  uint16_t type = opcode - Instruction::SPUT;
+  uint16_t type = SPutMemAccessType(static_cast<Instruction::Code>(opcode));
   if (!field_info.IsResolved()) {
     // Unresolved fields always alias with everything of the same type.
     // Use mir->offset as modifier; without elaborate inlining, it will be unique.
@@ -1373,7 +1372,7 @@
     // Nothing to do, resolved volatile fields always get a new memory version anyway and
     // can't alias with resolved non-volatile fields.
   } else {
-    uint16_t field_id = gvn_->GetFieldId(field_info, type);
+    uint16_t field_id = gvn_->GetSFieldId(mir);
     uint16_t value = (opcode == Instruction::SPUT_WIDE)
                      ? GetOperandValueWide(mir->ssa_rep->uses[0])
                      : GetOperandValue(mir->ssa_rep->uses[0]);
@@ -1397,7 +1396,7 @@
 void LocalValueNumbering::RemoveSFieldsForType(uint16_t type) {
   // Erase all static fields of this type from the sfield_value_map_.
   for (auto it = sfield_value_map_.begin(), end = sfield_value_map_.end(); it != end; ) {
-    if (gvn_->GetFieldType(it->first) == type) {
+    if (gvn_->GetSFieldType(it->first) == type) {
       it = sfield_value_map_.erase(it);
     } else {
       ++it;
diff --git a/compiler/dex/local_value_numbering_test.cc b/compiler/dex/local_value_numbering_test.cc
index 824c323..51aa9d9 100644
--- a/compiler/dex/local_value_numbering_test.cc
+++ b/compiler/dex/local_value_numbering_test.cc
@@ -15,6 +15,7 @@
  */
 
 #include "compiler_internals.h"
+#include "dex/mir_field_info.h"
 #include "global_value_numbering.h"
 #include "local_value_numbering.h"
 #include "gtest/gtest.h"
@@ -28,6 +29,7 @@
     uintptr_t declaring_dex_file;
     uint16_t declaring_field_idx;
     bool is_volatile;
+    DexMemAccessType type;
   };
 
   struct SFieldDef {
@@ -35,6 +37,7 @@
     uintptr_t declaring_dex_file;
     uint16_t declaring_field_idx;
     bool is_volatile;
+    DexMemAccessType type;
   };
 
   struct MIRDef {
@@ -90,12 +93,11 @@
     cu_.mir_graph->ifield_lowering_infos_.reserve(count);
     for (size_t i = 0u; i != count; ++i) {
       const IFieldDef* def = &defs[i];
-      MirIFieldLoweringInfo field_info(def->field_idx);
+      MirIFieldLoweringInfo field_info(def->field_idx, def->type);
       if (def->declaring_dex_file != 0u) {
         field_info.declaring_dex_file_ = reinterpret_cast<const DexFile*>(def->declaring_dex_file);
         field_info.declaring_field_idx_ = def->declaring_field_idx;
-        field_info.flags_ = 0u |  // Without kFlagIsStatic.
-            (def->is_volatile ? MirIFieldLoweringInfo::kFlagIsVolatile : 0u);
+        field_info.flags_ &= ~(def->is_volatile ? 0u : MirSFieldLoweringInfo::kFlagIsVolatile);
       }
       cu_.mir_graph->ifield_lowering_infos_.push_back(field_info);
     }
@@ -111,15 +113,14 @@
     cu_.mir_graph->sfield_lowering_infos_.reserve(count);
     for (size_t i = 0u; i != count; ++i) {
       const SFieldDef* def = &defs[i];
-      MirSFieldLoweringInfo field_info(def->field_idx);
+      MirSFieldLoweringInfo field_info(def->field_idx, def->type);
       // Mark even unresolved fields as initialized.
-      field_info.flags_ = MirSFieldLoweringInfo::kFlagIsStatic |
-          MirSFieldLoweringInfo::kFlagClassIsInitialized;
+      field_info.flags_ |= MirSFieldLoweringInfo::kFlagClassIsInitialized;
       // NOTE: MirSFieldLoweringInfo::kFlagClassIsInDexCache isn't used by LVN.
       if (def->declaring_dex_file != 0u) {
         field_info.declaring_dex_file_ = reinterpret_cast<const DexFile*>(def->declaring_dex_file);
         field_info.declaring_field_idx_ = def->declaring_field_idx;
-        field_info.flags_ |= (def->is_volatile ? MirSFieldLoweringInfo::kFlagIsVolatile : 0u);
+        field_info.flags_ &= ~(def->is_volatile ? 0u : MirSFieldLoweringInfo::kFlagIsVolatile);
       }
       cu_.mir_graph->sfield_lowering_infos_.push_back(field_info);
     }
@@ -140,12 +141,16 @@
       mir->dalvikInsn.opcode = def->opcode;
       mir->dalvikInsn.vB = static_cast<int32_t>(def->value);
       mir->dalvikInsn.vB_wide = def->value;
-      if (def->opcode >= Instruction::IGET && def->opcode <= Instruction::IPUT_SHORT) {
+      if (IsInstructionIGetOrIPut(def->opcode)) {
         ASSERT_LT(def->field_info, cu_.mir_graph->ifield_lowering_infos_.size());
         mir->meta.ifield_lowering_info = def->field_info;
-      } else if (def->opcode >= Instruction::SGET && def->opcode <= Instruction::SPUT_SHORT) {
+        ASSERT_EQ(cu_.mir_graph->ifield_lowering_infos_[def->field_info].MemAccessType(),
+                  IGetOrIPutMemAccessType(def->opcode));
+      } else if (IsInstructionSGetOrSPut(def->opcode)) {
         ASSERT_LT(def->field_info, cu_.mir_graph->sfield_lowering_infos_.size());
         mir->meta.sfield_lowering_info = def->field_info;
+        ASSERT_EQ(cu_.mir_graph->sfield_lowering_infos_[def->field_info].MemAccessType(),
+                  SGetOrSPutMemAccessType(def->opcode));
       }
       mir->ssa_rep = &ssa_reps_[i];
       mir->ssa_rep->num_uses = def->num_uses;
@@ -177,6 +182,13 @@
   }
 
   void PerformLVN() {
+    cu_.mir_graph->temp_.gvn.ifield_ids_ =  GlobalValueNumbering::PrepareGvnFieldIds(
+        allocator_.get(), cu_.mir_graph->ifield_lowering_infos_);
+    cu_.mir_graph->temp_.gvn.sfield_ids_ =  GlobalValueNumbering::PrepareGvnFieldIds(
+        allocator_.get(), cu_.mir_graph->sfield_lowering_infos_);
+    gvn_.reset(new (allocator_.get()) GlobalValueNumbering(&cu_, allocator_.get(),
+                                                           GlobalValueNumbering::kModeLvn));
+    lvn_.reset(new (allocator_.get()) LocalValueNumbering(gvn_.get(), 0u, allocator_.get()));
     value_names_.resize(mir_count_);
     for (size_t i = 0; i != mir_count_; ++i) {
       value_names_[i] =  lvn_->GetValueNumber(&mirs_[i]);
@@ -196,9 +208,6 @@
         value_names_() {
     cu_.mir_graph.reset(new MIRGraph(&cu_, &cu_.arena));
     allocator_.reset(ScopedArenaAllocator::Create(&cu_.arena_stack));
-    gvn_.reset(new (allocator_.get()) GlobalValueNumbering(&cu_, allocator_.get(),
-                                                           GlobalValueNumbering::kModeLvn));
-    lvn_.reset(new (allocator_.get()) LocalValueNumbering(gvn_.get(), 0u, allocator_.get()));
   }
 
   ArenaPool pool_;
@@ -214,7 +223,7 @@
 
 TEST_F(LocalValueNumberingTest, IGetIGetInvokeIGet) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_IGET(Instruction::IGET, 0u, 10u, 0u),
@@ -237,8 +246,8 @@
 
 TEST_F(LocalValueNumberingTest, IGetIPutIGetIGetIGet) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
-      { 2u, 1u, 2u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessObject },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_IGET(Instruction::IGET_OBJECT, 0u, 10u, 0u),
@@ -262,7 +271,7 @@
 
 TEST_F(LocalValueNumberingTest, UniquePreserve1) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_INSTANCE, 10u),
@@ -284,7 +293,7 @@
 
 TEST_F(LocalValueNumberingTest, UniquePreserve2) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_INSTANCE, 11u),
@@ -306,7 +315,7 @@
 
 TEST_F(LocalValueNumberingTest, UniquePreserveAndEscape) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_INSTANCE, 10u),
@@ -331,8 +340,8 @@
 
 TEST_F(LocalValueNumberingTest, Volatile) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
-      { 2u, 1u, 2u, true },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, true, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_IGET(Instruction::IGET, 0u, 10u, 1u),  // Volatile.
@@ -358,9 +367,9 @@
 
 TEST_F(LocalValueNumberingTest, UnresolvedIField) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },  // Resolved field #1.
-      { 2u, 1u, 2u, false },  // Resolved field #2.
-      { 3u, 0u, 0u, false },  // Unresolved field.
+      { 1u, 1u, 1u, false, kDexMemAccessWord },  // Resolved field #1.
+      { 2u, 1u, 2u, false, kDexMemAccessWide },  // Resolved field #2.
+      { 3u, 0u, 0u, false, kDexMemAccessWord },  // Unresolved field.
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_INSTANCE, 20u),
@@ -407,9 +416,9 @@
 
 TEST_F(LocalValueNumberingTest, UnresolvedSField) {
   static const SFieldDef sfields[] = {
-      { 1u, 1u, 1u, false },  // Resolved field #1.
-      { 2u, 1u, 2u, false },  // Resolved field #2.
-      { 3u, 0u, 0u, false },  // Unresolved field.
+      { 1u, 1u, 1u, false, kDexMemAccessWord },  // Resolved field #1.
+      { 2u, 1u, 2u, false, kDexMemAccessWide },  // Resolved field #2.
+      { 3u, 0u, 0u, false, kDexMemAccessWord },  // Unresolved field.
   };
   static const MIRDef mirs[] = {
       DEF_SGET(Instruction::SGET, 0u, 0u),            // Resolved field #1.
@@ -438,11 +447,11 @@
 
 TEST_F(LocalValueNumberingTest, UninitializedSField) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },  // Resolved field #1.
+      { 1u, 1u, 1u, false, kDexMemAccessWord },  // Resolved field #1.
   };
   static const SFieldDef sfields[] = {
-      { 1u, 1u, 1u, false },  // Resolved field #1.
-      { 2u, 1u, 2u, false },  // Resolved field #2; uninitialized.
+      { 1u, 1u, 1u, false, kDexMemAccessWord },  // Resolved field #1.
+      { 2u, 1u, 2u, false, kDexMemAccessWord },  // Resolved field #2; uninitialized.
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_INSTANCE, 200u),
@@ -487,11 +496,11 @@
 
 TEST_F(LocalValueNumberingTest, SameValueInDifferentMemoryLocations) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
-      { 2u, 1u, 2u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
   };
   static const SFieldDef sfields[] = {
-      { 3u, 1u, 3u, false },
+      { 3u, 1u, 3u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_ARRAY, 201u),
@@ -551,12 +560,12 @@
 
 TEST_F(LocalValueNumberingTest, EscapingRefs) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },  // Field #1.
-      { 2u, 1u, 2u, false },  // Field #2.
-      { 3u, 1u, 3u, false },  // Reference field for storing escaping refs.
-      { 4u, 1u, 4u, false },  // Wide.
-      { 5u, 0u, 0u, false },  // Unresolved field, int.
-      { 6u, 0u, 0u, false },  // Unresolved field, wide.
+      { 1u, 1u, 1u, false, kDexMemAccessWord },    // Field #1.
+      { 2u, 1u, 2u, false, kDexMemAccessWord },    // Field #2.
+      { 3u, 1u, 3u, false, kDexMemAccessObject },  // For storing escaping refs.
+      { 4u, 1u, 4u, false, kDexMemAccessWide },    // Wide.
+      { 5u, 0u, 0u, false, kDexMemAccessWord },    // Unresolved field, int.
+      { 6u, 0u, 0u, false, kDexMemAccessWide },    // Unresolved field, wide.
   };
   static const MIRDef mirs[] = {
       DEF_UNIQUE_REF(Instruction::NEW_INSTANCE, 20u),
@@ -634,11 +643,11 @@
 
 TEST_F(LocalValueNumberingTest, StoringSameValueKeepsMemoryVersion) {
   static const IFieldDef ifields[] = {
-      { 1u, 1u, 1u, false },
-      { 2u, 1u, 2u, false },
+      { 1u, 1u, 1u, false, kDexMemAccessWord },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
   };
   static const SFieldDef sfields[] = {
-      { 2u, 1u, 2u, false },
+      { 2u, 1u, 2u, false, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_IGET(Instruction::IGET, 0u, 30u, 0u),
@@ -716,8 +725,8 @@
 
 TEST_F(LocalValueNumberingTest, ClInitOnSget) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, false },
-      { 1u, 2u, 1u, false },
+      { 0u, 1u, 0u, false, kDexMemAccessObject },
+      { 1u, 2u, 1u, false, kDexMemAccessObject },
   };
   static const MIRDef mirs[] = {
       DEF_SGET(Instruction::SGET_OBJECT, 0u, 0u),
diff --git a/compiler/dex/mir_analysis.cc b/compiler/dex/mir_analysis.cc
index 44f69ba..7b53b14 100644
--- a/compiler/dex/mir_analysis.cc
+++ b/compiler/dex/mir_analysis.cc
@@ -21,6 +21,7 @@
 #include "dataflow_iterator-inl.h"
 #include "dex_instruction.h"
 #include "dex_instruction-inl.h"
+#include "dex/mir_field_info.h"
 #include "dex/verified_method.h"
 #include "dex/quick/dex_file_method_inliner.h"
 #include "dex/quick/dex_file_to_method_inliner_map.h"
@@ -1204,6 +1205,8 @@
   ScopedArenaAllocator allocator(&cu_->arena_stack);
   uint16_t* field_idxs =
       reinterpret_cast<uint16_t*>(allocator.Alloc(max_refs * sizeof(uint16_t), kArenaAllocMisc));
+  DexMemAccessType* field_types = reinterpret_cast<DexMemAccessType*>(
+      allocator.Alloc(max_refs * sizeof(DexMemAccessType), kArenaAllocMisc));
 
   // Find IGET/IPUT/SGET/SPUT insns, store IGET/IPUT fields at the beginning, SGET/SPUT at the end.
   size_t ifield_pos = 0u;
@@ -1214,38 +1217,41 @@
       continue;
     }
     for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) {
-      if (mir->dalvikInsn.opcode >= Instruction::IGET &&
-          mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) {
-        // Get field index and try to find it among existing indexes. If found, it's usually among
-        // the last few added, so we'll start the search from ifield_pos/sfield_pos. Though this
-        // is a linear search, it actually performs much better than map based approach.
-        if (mir->dalvikInsn.opcode <= Instruction::IPUT_SHORT) {
-          uint16_t field_idx = mir->dalvikInsn.vC;
-          size_t i = ifield_pos;
-          while (i != 0u && field_idxs[i - 1] != field_idx) {
-            --i;
-          }
-          if (i != 0u) {
-            mir->meta.ifield_lowering_info = i - 1;
-          } else {
-            mir->meta.ifield_lowering_info = ifield_pos;
-            field_idxs[ifield_pos++] = field_idx;
-          }
-        } else {
-          uint16_t field_idx = mir->dalvikInsn.vB;
-          size_t i = sfield_pos;
-          while (i != max_refs && field_idxs[i] != field_idx) {
-            ++i;
-          }
-          if (i != max_refs) {
-            mir->meta.sfield_lowering_info = max_refs - i - 1u;
-          } else {
-            mir->meta.sfield_lowering_info = max_refs - sfield_pos;
-            field_idxs[--sfield_pos] = field_idx;
-          }
+      // Get field index and try to find it among existing indexes. If found, it's usually among
+      // the last few added, so we'll start the search from ifield_pos/sfield_pos. Though this
+      // is a linear search, it actually performs much better than map based approach.
+      if (IsInstructionIGetOrIPut(mir->dalvikInsn.opcode)) {
+        uint16_t field_idx = mir->dalvikInsn.vC;
+        size_t i = ifield_pos;
+        while (i != 0u && field_idxs[i - 1] != field_idx) {
+          --i;
         }
-        DCHECK_LE(ifield_pos, sfield_pos);
+        if (i != 0u) {
+          mir->meta.ifield_lowering_info = i - 1;
+          DCHECK_EQ(field_types[i - 1], IGetOrIPutMemAccessType(mir->dalvikInsn.opcode));
+        } else {
+          mir->meta.ifield_lowering_info = ifield_pos;
+          field_idxs[ifield_pos] = field_idx;
+          field_types[ifield_pos] = IGetOrIPutMemAccessType(mir->dalvikInsn.opcode);
+          ++ifield_pos;
+        }
+      } else if (IsInstructionSGetOrSPut(mir->dalvikInsn.opcode)) {
+        uint16_t field_idx = mir->dalvikInsn.vB;
+        size_t i = sfield_pos;
+        while (i != max_refs && field_idxs[i] != field_idx) {
+          ++i;
+        }
+        if (i != max_refs) {
+          mir->meta.sfield_lowering_info = max_refs - i - 1u;
+          DCHECK_EQ(field_types[i], SGetOrSPutMemAccessType(mir->dalvikInsn.opcode));
+        } else {
+          mir->meta.sfield_lowering_info = max_refs - sfield_pos;
+          --sfield_pos;
+          field_idxs[sfield_pos] = field_idx;
+          field_types[sfield_pos] = SGetOrSPutMemAccessType(mir->dalvikInsn.opcode);
+        }
       }
+      DCHECK_LE(ifield_pos, sfield_pos);
     }
   }
 
@@ -1254,7 +1260,7 @@
     DCHECK_EQ(ifield_lowering_infos_.size(), 0u);
     ifield_lowering_infos_.reserve(ifield_pos);
     for (size_t pos = 0u; pos != ifield_pos; ++pos) {
-      ifield_lowering_infos_.push_back(MirIFieldLoweringInfo(field_idxs[pos]));
+      ifield_lowering_infos_.push_back(MirIFieldLoweringInfo(field_idxs[pos], field_types[pos]));
     }
     MirIFieldLoweringInfo::Resolve(cu_->compiler_driver, GetCurrentDexCompilationUnit(),
                                    ifield_lowering_infos_.data(), ifield_pos);
@@ -1266,7 +1272,7 @@
     sfield_lowering_infos_.reserve(max_refs - sfield_pos);
     for (size_t pos = max_refs; pos != sfield_pos;) {
       --pos;
-      sfield_lowering_infos_.push_back(MirSFieldLoweringInfo(field_idxs[pos]));
+      sfield_lowering_infos_.push_back(MirSFieldLoweringInfo(field_idxs[pos], field_types[pos]));
     }
     MirSFieldLoweringInfo::Resolve(cu_->compiler_driver, GetCurrentDexCompilationUnit(),
                                    sfield_lowering_infos_.data(), max_refs - sfield_pos);
@@ -1329,19 +1335,10 @@
       continue;
     }
     for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) {
-      if (mir->dalvikInsn.opcode >= Instruction::INVOKE_VIRTUAL &&
-          mir->dalvikInsn.opcode <= Instruction::INVOKE_INTERFACE_RANGE &&
-          mir->dalvikInsn.opcode != Instruction::RETURN_VOID_BARRIER) {
+      if (IsInstructionInvoke(mir->dalvikInsn.opcode)) {
         // Decode target method index and invoke type.
-        uint16_t target_method_idx;
-        uint16_t invoke_type_idx;
-        if (mir->dalvikInsn.opcode <= Instruction::INVOKE_INTERFACE) {
-          target_method_idx = mir->dalvikInsn.vB;
-          invoke_type_idx = mir->dalvikInsn.opcode - Instruction::INVOKE_VIRTUAL;
-        } else {
-          target_method_idx = mir->dalvikInsn.vB;
-          invoke_type_idx = mir->dalvikInsn.opcode - Instruction::INVOKE_VIRTUAL_RANGE;
-        }
+        uint16_t target_method_idx = mir->dalvikInsn.vB;
+        DexInvokeType invoke_type_idx = InvokeInstructionType(mir->dalvikInsn.opcode);
 
         // Find devirtualization target.
         // TODO: The devirt map is ordered by the dex pc here. Is there a way to get INVOKEs
diff --git a/compiler/dex/mir_field_info.cc b/compiler/dex/mir_field_info.cc
index 1db3b5b..53afcad 100644
--- a/compiler/dex/mir_field_info.cc
+++ b/compiler/dex/mir_field_info.cc
@@ -35,7 +35,7 @@
     DCHECK(field_infos != nullptr);
     DCHECK_NE(count, 0u);
     for (auto it = field_infos, end = field_infos + count; it != end; ++it) {
-      MirIFieldLoweringInfo unresolved(it->field_idx_);
+      MirIFieldLoweringInfo unresolved(it->field_idx_, it->MemAccessType());
       DCHECK_EQ(memcmp(&unresolved, &*it, sizeof(*it)), 0);
     }
   }
@@ -66,6 +66,7 @@
     std::pair<bool, bool> fast_path = compiler_driver->IsFastInstanceField(
         dex_cache.Get(), referrer_class.Get(), resolved_field, field_idx);
     it->flags_ = 0u |  // Without kFlagIsStatic.
+        (it->flags_ & (kMemAccessTypeMask << kBitMemAccessTypeBegin)) |
         (is_volatile ? kFlagIsVolatile : 0u) |
         (fast_path.first ? kFlagFastGet : 0u) |
         (fast_path.second ? kFlagFastPut : 0u);
@@ -79,7 +80,7 @@
     DCHECK(field_infos != nullptr);
     DCHECK_NE(count, 0u);
     for (auto it = field_infos, end = field_infos + count; it != end; ++it) {
-      MirSFieldLoweringInfo unresolved(it->field_idx_);
+      MirSFieldLoweringInfo unresolved(it->field_idx_, it->MemAccessType());
       // In 64-bit builds, there's padding after storage_index_, don't include it in memcmp.
       size_t size = OFFSETOF_MEMBER(MirSFieldLoweringInfo, storage_index_) +
           sizeof(it->storage_index_);
@@ -114,6 +115,7 @@
     std::pair<bool, bool> fast_path = compiler_driver->IsFastStaticField(
         dex_cache.Get(), referrer_class, resolved_field, field_idx, &it->storage_index_);
     uint16_t flags = kFlagIsStatic |
+        (it->flags_ & (kMemAccessTypeMask << kBitMemAccessTypeBegin)) |
         (is_volatile ? kFlagIsVolatile : 0u) |
         (fast_path.first ? kFlagFastGet : 0u) |
         (fast_path.second ? kFlagFastPut : 0u);
diff --git a/compiler/dex/mir_field_info.h b/compiler/dex/mir_field_info.h
index e97f7a0..ff427f8 100644
--- a/compiler/dex/mir_field_info.h
+++ b/compiler/dex/mir_field_info.h
@@ -20,6 +20,7 @@
 #include "base/macros.h"
 #include "dex_file.h"
 #include "offsets.h"
+#include "utils/dex_instruction_utils.h"
 
 namespace art {
 
@@ -63,18 +64,27 @@
     return (flags_ & kFlagIsVolatile) != 0u;
   }
 
+  DexMemAccessType MemAccessType() const {
+    return static_cast<DexMemAccessType>((flags_ >> kBitMemAccessTypeBegin) & kMemAccessTypeMask);
+  }
+
  protected:
   enum {
     kBitIsStatic = 0,
     kBitIsVolatile,
-    kFieldInfoBitEnd
+    kBitMemAccessTypeBegin,
+    kBitMemAccessTypeEnd = kBitMemAccessTypeBegin + 3,  // 3 bits for raw type.
+    kFieldInfoBitEnd = kBitMemAccessTypeEnd
   };
   static constexpr uint16_t kFlagIsVolatile = 1u << kBitIsVolatile;
   static constexpr uint16_t kFlagIsStatic = 1u << kBitIsStatic;
+  static constexpr uint16_t kMemAccessTypeMask = 7u;
+  static_assert((1u << (kBitMemAccessTypeEnd - kBitMemAccessTypeBegin)) - 1u == kMemAccessTypeMask,
+                "Invalid raw type mask");
 
-  MirFieldInfo(uint16_t field_idx, uint16_t flags)
+  MirFieldInfo(uint16_t field_idx, uint16_t flags, DexMemAccessType type)
       : field_idx_(field_idx),
-        flags_(flags),
+        flags_(flags | static_cast<uint16_t>(type) << kBitMemAccessTypeBegin),
         declaring_field_idx_(0u),
         declaring_class_idx_(0u),
         declaring_dex_file_(nullptr) {
@@ -107,8 +117,8 @@
       LOCKS_EXCLUDED(Locks::mutator_lock_);
 
   // Construct an unresolved instance field lowering info.
-  explicit MirIFieldLoweringInfo(uint16_t field_idx)
-      : MirFieldInfo(field_idx, kFlagIsVolatile),  // Without kFlagIsStatic.
+  explicit MirIFieldLoweringInfo(uint16_t field_idx, DexMemAccessType type)
+      : MirFieldInfo(field_idx, kFlagIsVolatile, type),  // Without kFlagIsStatic.
         field_offset_(0u) {
   }
 
@@ -155,8 +165,8 @@
       LOCKS_EXCLUDED(Locks::mutator_lock_);
 
   // Construct an unresolved static field lowering info.
-  explicit MirSFieldLoweringInfo(uint16_t field_idx)
-      : MirFieldInfo(field_idx, kFlagIsVolatile | kFlagIsStatic),
+  explicit MirSFieldLoweringInfo(uint16_t field_idx, DexMemAccessType type)
+      : MirFieldInfo(field_idx, kFlagIsVolatile | kFlagIsStatic, type),
         field_offset_(0u),
         storage_index_(DexFile::kDexNoIndex) {
   }
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index d77ad6f..63b1f2d 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -661,13 +661,29 @@
   void DoCacheFieldLoweringInfo();
 
   const MirIFieldLoweringInfo& GetIFieldLoweringInfo(MIR* mir) const {
-    DCHECK_LT(mir->meta.ifield_lowering_info, ifield_lowering_infos_.size());
-    return ifield_lowering_infos_[mir->meta.ifield_lowering_info];
+    return GetIFieldLoweringInfo(mir->meta.ifield_lowering_info);
+  }
+
+  const MirIFieldLoweringInfo& GetIFieldLoweringInfo(uint32_t lowering_info) const {
+    DCHECK_LT(lowering_info, ifield_lowering_infos_.size());
+    return ifield_lowering_infos_[lowering_info];
+  }
+
+  size_t GetIFieldLoweringInfoCount() const {
+    return ifield_lowering_infos_.size();
   }
 
   const MirSFieldLoweringInfo& GetSFieldLoweringInfo(MIR* mir) const {
-    DCHECK_LT(mir->meta.sfield_lowering_info, sfield_lowering_infos_.size());
-    return sfield_lowering_infos_[mir->meta.sfield_lowering_info];
+    return GetSFieldLoweringInfo(mir->meta.sfield_lowering_info);
+  }
+
+  const MirSFieldLoweringInfo& GetSFieldLoweringInfo(uint32_t lowering_info) const {
+    DCHECK_LT(lowering_info, sfield_lowering_infos_.size());
+    return sfield_lowering_infos_[lowering_info];
+  }
+
+  size_t GetSFieldLoweringInfoCount() const {
+    return sfield_lowering_infos_.size();
   }
 
   void DoCacheMethodLoweringInfo();
@@ -1035,6 +1051,21 @@
   bool ApplyGlobalValueNumberingGate();
   bool ApplyGlobalValueNumbering(BasicBlock* bb);
   void ApplyGlobalValueNumberingEnd();
+
+  uint16_t GetGvnIFieldId(MIR* mir) const {
+    DCHECK(IsInstructionIGetOrIPut(mir->dalvikInsn.opcode));
+    DCHECK_LT(mir->meta.ifield_lowering_info, ifield_lowering_infos_.size());
+    DCHECK(temp_.gvn.ifield_ids_ != nullptr);
+    return temp_.gvn.ifield_ids_[mir->meta.ifield_lowering_info];
+  }
+
+  uint16_t GetGvnSFieldId(MIR* mir) const {
+    DCHECK(IsInstructionSGetOrSPut(mir->dalvikInsn.opcode));
+    DCHECK_LT(mir->meta.sfield_lowering_info, sfield_lowering_infos_.size());
+    DCHECK(temp_.gvn.sfield_ids_ != nullptr);
+    return temp_.gvn.sfield_ids_[mir->meta.sfield_lowering_info];
+  }
+
   /*
    * Type inference handling helpers.  Because Dalvik's bytecode is not fully typed,
    * we have to do some work to figure out the sreg type.  For some operations it is
@@ -1300,6 +1331,8 @@
     // Global value numbering.
     struct {
       GlobalValueNumbering* gvn;
+      uint16_t* ifield_ids_;  // Part of GVN/LVN but cached here for LVN to avoid recalculation.
+      uint16_t* sfield_ids_;  // Ditto.
     } gvn;
   } temp_;
   static const int kInvalidEntry = -1;
diff --git a/compiler/dex/mir_optimization.cc b/compiler/dex/mir_optimization.cc
index d025d08..fd564ed 100644
--- a/compiler/dex/mir_optimization.cc
+++ b/compiler/dex/mir_optimization.cc
@@ -19,6 +19,7 @@
 #include "dataflow_iterator-inl.h"
 #include "global_value_numbering.h"
 #include "local_value_numbering.h"
+#include "mir_field_info.h"
 #include "quick/dex_file_method_inliner.h"
 #include "quick/dex_file_to_method_inliner_map.h"
 #include "stack.h"
@@ -217,10 +218,6 @@
 static_assert(arraysize(kIfCcZConditionCodes) == Instruction::IF_LEZ - Instruction::IF_EQZ + 1,
               "if_ccz_ccodes_size1");
 
-static constexpr bool IsInstructionIfCcZ(Instruction::Code opcode) {
-  return Instruction::IF_EQZ <= opcode && opcode <= Instruction::IF_LEZ;
-}
-
 static constexpr ConditionCode ConditionCodeForIfCcZ(Instruction::Code opcode) {
   return kIfCcZConditionCodes[opcode - Instruction::IF_EQZ];
 }
@@ -1159,8 +1156,7 @@
     for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) {
       if (bb->block_type == kDalvikByteCode) {
         for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) {
-          if (mir->dalvikInsn.opcode >= Instruction::SGET &&
-              mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) {
+          if (IsInstructionSGetOrSPut(mir->dalvikInsn.opcode)) {
             const MirSFieldLoweringInfo& field_info = GetSFieldLoweringInfo(mir);
             if (!field_info.IsReferrersClass()) {
               DCHECK_LT(class_to_index_map.size(), 0xffffu);
@@ -1176,8 +1172,7 @@
               // Using offset/2 for index into temp_.cice.indexes.
               temp_.cice.indexes[mir->offset / 2u] = index;
             }
-          } else if (mir->dalvikInsn.opcode == Instruction::INVOKE_STATIC ||
-              mir->dalvikInsn.opcode == Instruction::INVOKE_STATIC_RANGE) {
+          } else if (IsInstructionInvokeStatic(mir->dalvikInsn.opcode)) {
             const MirMethodLoweringInfo& method_info = GetMethodLoweringInfo(mir);
             DCHECK(method_info.IsStatic());
             if (method_info.FastPath() && !method_info.IsReferrersClass()) {
@@ -1261,12 +1256,10 @@
       // NOTE: index != 0xffff does not guarantee that this is an SGET/SPUT/INVOKE_STATIC.
       // Dex instructions with width 1 can have the same offset/2.
 
-      if (mir->dalvikInsn.opcode >= Instruction::SGET &&
-          mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) {
+      if (IsInstructionSGetOrSPut(mir->dalvikInsn.opcode)) {
         check_initialization = true;
         check_dex_cache = true;
-      } else if (mir->dalvikInsn.opcode == Instruction::INVOKE_STATIC ||
-               mir->dalvikInsn.opcode == Instruction::INVOKE_STATIC_RANGE) {
+      } else if (IsInstructionInvokeStatic(mir->dalvikInsn.opcode)) {
         check_initialization = true;
         // NOTE: INVOKE_STATIC doesn't guarantee that the type will be in the dex cache.
       }
@@ -1333,6 +1326,10 @@
 
   DCHECK(temp_scoped_alloc_ == nullptr);
   temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack));
+  temp_.gvn.ifield_ids_ =
+      GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), ifield_lowering_infos_);
+  temp_.gvn.sfield_ids_ =
+      GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), sfield_lowering_infos_);
   DCHECK(temp_.gvn.gvn == nullptr);
   temp_.gvn.gvn = new (temp_scoped_alloc_.get()) GlobalValueNumbering(
       cu_, temp_scoped_alloc_.get(), GlobalValueNumbering::kModeGvn);
@@ -1378,6 +1375,8 @@
 
   delete temp_.gvn.gvn;
   temp_.gvn.gvn = nullptr;
+  temp_.gvn.ifield_ids_ = nullptr;
+  temp_.gvn.sfield_ids_ = nullptr;
   DCHECK(temp_scoped_alloc_ != nullptr);
   temp_scoped_alloc_.reset();
 }
@@ -1396,7 +1395,8 @@
       cu_, cu_->class_loader, cu_->class_linker, *target.dex_file,
       nullptr /* code_item not used */, 0u /* class_def_idx not used */, target.dex_method_index,
       0u /* access_flags not used */, nullptr /* verified_method not used */);
-  MirIFieldLoweringInfo inlined_field_info(field_idx);
+  DexMemAccessType type = IGetOrIPutMemAccessType(iget_or_iput->dalvikInsn.opcode);
+  MirIFieldLoweringInfo inlined_field_info(field_idx, type);
   MirIFieldLoweringInfo::Resolve(cu_->compiler_driver, &inlined_unit, &inlined_field_info, 1u);
   DCHECK(inlined_field_info.IsResolved());
 
@@ -1544,6 +1544,14 @@
 }
 
 void MIRGraph::BasicBlockOptimization() {
+  if ((cu_->disable_opt & (1 << kLocalValueNumbering)) == 0) {
+    temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack));
+    temp_.gvn.ifield_ids_ =
+        GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), ifield_lowering_infos_);
+    temp_.gvn.sfield_ids_ =
+        GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), sfield_lowering_infos_);
+  }
+
   if ((cu_->disable_opt & (1 << kSuppressExceptionEdges)) != 0) {
     ClearAllVisitedFlags();
     PreOrderDfsIterator iter2(this);
@@ -1560,6 +1568,11 @@
       BasicBlockOpt(bb);
     }
   }
+
+  // Clean up after LVN.
+  temp_.gvn.ifield_ids_ = nullptr;
+  temp_.gvn.sfield_ids_ = nullptr;
+  temp_scoped_alloc_.reset();
 }
 
 }  // namespace art
diff --git a/compiler/dex/mir_optimization_test.cc b/compiler/dex/mir_optimization_test.cc
index 8874faf..c794cc6 100644
--- a/compiler/dex/mir_optimization_test.cc
+++ b/compiler/dex/mir_optimization_test.cc
@@ -19,6 +19,7 @@
 #include "compiler_internals.h"
 #include "dataflow_iterator.h"
 #include "dataflow_iterator-inl.h"
+#include "dex/mir_field_info.h"
 #include "gtest/gtest.h"
 
 namespace art {
@@ -236,15 +237,17 @@
       ASSERT_LT(def->bbid, cu_.mir_graph->block_list_.size());
       BasicBlock* bb = cu_.mir_graph->block_list_[def->bbid];
       bb->AppendMIR(mir);
-      if (def->opcode >= Instruction::SGET && def->opcode <= Instruction::SPUT_SHORT) {
-        ASSERT_LT(def->field_or_method_info, cu_.mir_graph->sfield_lowering_infos_.size());
-        mir->meta.sfield_lowering_info = def->field_or_method_info;
-      } else if (def->opcode >= Instruction::IGET && def->opcode <= Instruction::IPUT_SHORT) {
+      if (IsInstructionIGetOrIPut(def->opcode)) {
         ASSERT_LT(def->field_or_method_info, cu_.mir_graph->ifield_lowering_infos_.size());
         mir->meta.ifield_lowering_info = def->field_or_method_info;
-      } else if (def->opcode >= Instruction::INVOKE_VIRTUAL &&
-          def->opcode < Instruction::INVOKE_INTERFACE_RANGE &&
-          def->opcode != Instruction::RETURN_VOID_BARRIER) {
+        ASSERT_EQ(cu_.mir_graph->ifield_lowering_infos_[def->field_or_method_info].MemAccessType(),
+                  IGetOrIPutMemAccessType(def->opcode));
+      } else if (IsInstructionSGetOrSPut(def->opcode)) {
+        ASSERT_LT(def->field_or_method_info, cu_.mir_graph->sfield_lowering_infos_.size());
+        mir->meta.sfield_lowering_info = def->field_or_method_info;
+        ASSERT_EQ(cu_.mir_graph->sfield_lowering_infos_[def->field_or_method_info].MemAccessType(),
+                  SGetOrSPutMemAccessType(def->opcode));
+      } else if (IsInstructionInvoke(def->opcode)) {
         ASSERT_LT(def->field_or_method_info, cu_.mir_graph->method_lowering_infos_.size());
         mir->meta.method_lowering_info = def->field_or_method_info;
       }
@@ -294,6 +297,7 @@
     uintptr_t declaring_dex_file;
     uint16_t declaring_class_idx;
     uint16_t declaring_field_idx;
+    DexMemAccessType type;
   };
 
   void DoPrepareSFields(const SFieldDef* defs, size_t count) {
@@ -301,12 +305,12 @@
     cu_.mir_graph->sfield_lowering_infos_.reserve(count);
     for (size_t i = 0u; i != count; ++i) {
       const SFieldDef* def = &defs[i];
-      MirSFieldLoweringInfo field_info(def->field_idx);
+      MirSFieldLoweringInfo field_info(def->field_idx, def->type);
       if (def->declaring_dex_file != 0u) {
         field_info.declaring_dex_file_ = reinterpret_cast<const DexFile*>(def->declaring_dex_file);
         field_info.declaring_class_idx_ = def->declaring_class_idx;
         field_info.declaring_field_idx_ = def->declaring_field_idx;
-        field_info.flags_ = MirSFieldLoweringInfo::kFlagIsStatic;
+        // We don't care about the volatile flag in these tests.
       }
       ASSERT_EQ(def->declaring_dex_file != 0u, field_info.IsResolved());
       ASSERT_FALSE(field_info.IsClassInitialized());
@@ -343,6 +347,7 @@
     uintptr_t declaring_dex_file;
     uint16_t declaring_class_idx;
     uint16_t declaring_field_idx;
+    DexMemAccessType type;
   };
 
   void DoPrepareIFields(const IFieldDef* defs, size_t count) {
@@ -350,11 +355,12 @@
     cu_.mir_graph->ifield_lowering_infos_.reserve(count);
     for (size_t i = 0u; i != count; ++i) {
       const IFieldDef* def = &defs[i];
-      MirIFieldLoweringInfo field_info(def->field_idx);
+      MirIFieldLoweringInfo field_info(def->field_idx, def->type);
       if (def->declaring_dex_file != 0u) {
         field_info.declaring_dex_file_ = reinterpret_cast<const DexFile*>(def->declaring_dex_file);
         field_info.declaring_class_idx_ = def->declaring_class_idx;
         field_info.declaring_field_idx_ = def->declaring_field_idx;
+        // We don't care about the volatile flag in these tests.
       }
       ASSERT_EQ(def->declaring_dex_file != 0u, field_info.IsResolved());
       cu_.mir_graph->ifield_lowering_infos_.push_back(field_info);
@@ -393,12 +399,12 @@
 
 TEST_F(ClassInitCheckEliminationTest, SingleBlock) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
-      { 2u, 1u, 2u, 2u },
-      { 3u, 1u, 3u, 3u },  // Same declaring class as sfield[4].
-      { 4u, 1u, 3u, 4u },  // Same declaring class as sfield[3].
-      { 5u, 0u, 0u, 0u },  // Unresolved.
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 2u, 2u, kDexMemAccessWord },
+      { 3u, 1u, 3u, 3u, kDexMemAccessWord },  // Same declaring class as sfield[4].
+      { 4u, 1u, 3u, 4u, kDexMemAccessWord },  // Same declaring class as sfield[3].
+      { 5u, 0u, 0u, 0u, kDexMemAccessWord },  // Unresolved.
   };
   static const MIRDef mirs[] = {
       DEF_SGET_SPUT(3u, Instruction::SPUT, 0u, 5u),  // Unresolved.
@@ -432,9 +438,9 @@
 
 TEST_F(ClassInitCheckEliminationTest, SingleBlockWithInvokes) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
-      { 2u, 1u, 2u, 2u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 2u, 2u, kDexMemAccessWord },
   };
   static const MethodDef methods[] = {
       { 0u, 1u, 0u, 0u, kStatic, kStatic, false, false },
@@ -473,17 +479,17 @@
 
 TEST_F(ClassInitCheckEliminationTest, Diamond) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
-      { 2u, 1u, 2u, 2u },
-      { 3u, 1u, 3u, 3u },
-      { 4u, 1u, 4u, 4u },
-      { 5u, 1u, 5u, 5u },
-      { 6u, 1u, 6u, 6u },
-      { 7u, 1u, 7u, 7u },
-      { 8u, 1u, 8u, 8u },  // Same declaring class as sfield[9].
-      { 9u, 1u, 8u, 9u },  // Same declaring class as sfield[8].
-      { 10u, 0u, 0u, 0u },  // Unresolved.
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 2u, 2u, kDexMemAccessWord },
+      { 3u, 1u, 3u, 3u, kDexMemAccessWord },
+      { 4u, 1u, 4u, 4u, kDexMemAccessWord },
+      { 5u, 1u, 5u, 5u, kDexMemAccessWord },
+      { 6u, 1u, 6u, 6u, kDexMemAccessWord },
+      { 7u, 1u, 7u, 7u, kDexMemAccessWord },
+      { 8u, 1u, 8u, 8u, kDexMemAccessWord },   // Same declaring class as sfield[9].
+      { 9u, 1u, 8u, 9u, kDexMemAccessWord },   // Same declaring class as sfield[8].
+      { 10u, 0u, 0u, 0u, kDexMemAccessWord },  // Unresolved.
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -539,11 +545,11 @@
 
 TEST_F(ClassInitCheckEliminationTest, DiamondWithInvokes) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
-      { 2u, 1u, 2u, 2u },
-      { 3u, 1u, 3u, 3u },
-      { 4u, 1u, 4u, 4u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 2u, 2u, kDexMemAccessWord },
+      { 3u, 1u, 3u, 3u, kDexMemAccessWord },
+      { 4u, 1u, 4u, 4u, kDexMemAccessWord },
   };
   static const MethodDef methods[] = {
       { 0u, 1u, 0u, 0u, kStatic, kStatic, false, false },
@@ -600,9 +606,9 @@
 
 TEST_F(ClassInitCheckEliminationTest, Loop) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
-      { 2u, 1u, 2u, 2u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 2u, 2u, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_SGET_SPUT(3u, Instruction::SGET, 0u, 0u),
@@ -631,7 +637,7 @@
 
 TEST_F(ClassInitCheckEliminationTest, LoopWithInvokes) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
   };
   static const MethodDef methods[] = {
       { 0u, 1u, 0u, 0u, kStatic, kStatic, false, false },
@@ -671,10 +677,10 @@
 
 TEST_F(ClassInitCheckEliminationTest, Catch) {
   static const SFieldDef sfields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
-      { 2u, 1u, 2u, 2u },
-      { 3u, 1u, 3u, 3u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 2u, 2u, kDexMemAccessWord },
+      { 3u, 1u, 3u, 3u, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_SGET_SPUT(3u, Instruction::SGET, 0u, 0u),  // Before the exception edge.
@@ -707,9 +713,9 @@
 
 TEST_F(NullCheckEliminationTest, SingleBlock) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 0u, 1u },
-      { 2u, 1u, 0u, 2u },  // Object.
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 0u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 0u, 2u, kDexMemAccessObject },
   };
   static const MIRDef mirs[] = {
       DEF_IGET_IPUT(3u, Instruction::IGET_OBJECT, 0u, 100u, 2u),
@@ -768,9 +774,9 @@
 
 TEST_F(NullCheckEliminationTest, Diamond) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 0u, 1u },
-      { 2u, 1u, 0u, 2u },  // int[].
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 0u, 1u, kDexMemAccessWord },
+      { 2u, 1u, 0u, 2u, kDexMemAccessObject },  // int[].
   };
   static const MIRDef mirs[] = {
       // NOTE: MIRs here are ordered by unique tests. They will be put into appropriate blocks.
@@ -816,8 +822,8 @@
 
 TEST_F(NullCheckEliminationTest, Loop) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_IGET_IPUT(3u, Instruction::IGET, 0u, 100u, 0u),
@@ -846,8 +852,8 @@
 
 TEST_F(NullCheckEliminationTest, Catch) {
   static const IFieldDef ifields[] = {
-      { 0u, 1u, 0u, 0u },
-      { 1u, 1u, 1u, 1u },
+      { 0u, 1u, 0u, 0u, kDexMemAccessWord },
+      { 1u, 1u, 1u, 1u, kDexMemAccessWord },
   };
   static const MIRDef mirs[] = {
       DEF_IGET_IPUT(3u, Instruction::IGET, 0u, 100u, 0u),  // Before the exception edge.
diff --git a/compiler/dex/quick/gen_common.cc b/compiler/dex/quick/gen_common.cc
index c00f90b..4dd24cb 100644
--- a/compiler/dex/quick/gen_common.cc
+++ b/compiler/dex/quick/gen_common.cc
@@ -583,6 +583,7 @@
 
 void Mir2Lir::GenSput(MIR* mir, RegLocation rl_src, OpSize size) {
   const MirSFieldLoweringInfo& field_info = mir_graph_->GetSFieldLoweringInfo(mir);
+  DCHECK_EQ(SPutMemAccessType(mir->dalvikInsn.opcode), field_info.MemAccessType());
   cu_->compiler_driver->ProcessedStaticField(field_info.FastPut(), field_info.IsReferrersClass());
   if (!SLOW_FIELD_PATH && field_info.FastPut()) {
     DCHECK_GE(field_info.FieldOffset().Int32Value(), 0);
@@ -701,6 +702,7 @@
 
 void Mir2Lir::GenSget(MIR* mir, RegLocation rl_dest, OpSize size, Primitive::Type type) {
   const MirSFieldLoweringInfo& field_info = mir_graph_->GetSFieldLoweringInfo(mir);
+  DCHECK_EQ(SGetMemAccessType(mir->dalvikInsn.opcode), field_info.MemAccessType());
   cu_->compiler_driver->ProcessedStaticField(field_info.FastGet(), field_info.IsReferrersClass());
 
   if (!SLOW_FIELD_PATH && field_info.FastGet()) {
@@ -839,6 +841,7 @@
 void Mir2Lir::GenIGet(MIR* mir, int opt_flags, OpSize size, Primitive::Type type,
                       RegLocation rl_dest, RegLocation rl_obj) {
   const MirIFieldLoweringInfo& field_info = mir_graph_->GetIFieldLoweringInfo(mir);
+  DCHECK_EQ(IGetMemAccessType(mir->dalvikInsn.opcode), field_info.MemAccessType());
   cu_->compiler_driver->ProcessedInstanceField(field_info.FastGet());
   if (!SLOW_FIELD_PATH && field_info.FastGet()) {
     RegisterClass reg_class = RegClassForFieldLoadStore(size, field_info.IsVolatile());
@@ -912,6 +915,7 @@
 void Mir2Lir::GenIPut(MIR* mir, int opt_flags, OpSize size,
                       RegLocation rl_src, RegLocation rl_obj) {
   const MirIFieldLoweringInfo& field_info = mir_graph_->GetIFieldLoweringInfo(mir);
+  DCHECK_EQ(IPutMemAccessType(mir->dalvikInsn.opcode), field_info.MemAccessType());
   cu_->compiler_driver->ProcessedInstanceField(field_info.FastPut());
   if (!SLOW_FIELD_PATH && field_info.FastPut()) {
     RegisterClass reg_class = RegClassForFieldLoadStore(size, field_info.IsVolatile());