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mc/compare: another round of tiny cleanups
[simgrid.git] / src / mc / compare.cpp
index 1fe48f4..6948be5 100644 (file)
-/* Copyright (c) 2008-2017. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2008-2019. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
 /** \file compare.cpp Memory snapshooting and comparison                    */
 
-#include <cinttypes>
-
-#include <array>
-#include <memory>
-#include <set>
-#include <utility>
-#include <unordered_set>
-
-#include "xbt/dynar.h"
-#include "xbt/sysdep.h"
-#include <xbt/mmalloc.h>
-
-#include <mc/mc.h>
-#include <mc/datatypes.h>
-
-#include "src/internal_config.h"
-
-#include "src/xbt/mmalloc/mmprivate.h"
-
-#if HAVE_SMPI
-#include "src/smpi/private.h"
-#include "src/smpi/private.hpp"
-#endif
-
-#include "src/mc/mc_forward.hpp"
-#include "src/mc/mc_private.h"
-#include "src/mc/mc_smx.h"
-#include "src/mc/mc_dwarf.hpp"
-#include "src/mc/Frame.hpp"
-#include "src/mc/ObjectInformation.hpp"
-#include "src/mc/Variable.hpp"
-#include "src/mc/mc_private.h"
-#include "src/mc/mc_snapshot.h"
-#include "src/mc/mc_dwarf.hpp"
-#include "src/mc/Type.hpp"
+#include "src/mc/mc_config.hpp"
+#include "src/mc/mc_private.hpp"
+#include "src/mc/mc_smx.hpp"
+#include "src/mc/sosp/Snapshot.hpp"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, xbt, "Logging specific to mc_compare in mc");
 
+using simgrid::mc::remote;
+
 namespace simgrid {
 namespace mc {
 
-struct HeapLocation;
-typedef std::array<HeapLocation, 2> HeapLocationPair;
-typedef std::set<HeapLocationPair> HeapLocationPairs;
-struct HeapArea;
-struct ProcessComparisonState;
-struct StateComparator;
-
-static int compare_heap_area(
-  StateComparator& state,
-  int process_index, const void *area1, const void* area2,
-  Snapshot* snapshot1, Snapshot* snapshot2,
-  HeapLocationPairs* previous, Type* type, int pointer_level);
-
-}
-}
-
-using simgrid::mc::remote;
-
 /*********************************** Heap comparison ***********************************/
 /***************************************************************************************/
 
-namespace simgrid {
-namespace mc {
-
-struct HeapLocation {
-  int block = 0;
-  int fragment = 0;
+class HeapLocation {
+public:
+  int block_    = 0;
+  int fragment_ = 0;
 
-  HeapLocation() {}
-  HeapLocation(int block, int fragment = 0) : block(block), fragment(fragment) {}
+  HeapLocation() = default;
+  HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
 
   bool operator==(HeapLocation const& that) const
   {
-    return block == that.block && fragment == that.fragment;
+    return block_ == that.block_ && fragment_ == that.fragment_;
   }
   bool operator<(HeapLocation const& that) const
   {
-    return std::make_pair(block, fragment)
-      < std::make_pair(that.block, that.fragment);
+    return std::make_pair(block_, fragment_) < std::make_pair(that.block_, that.fragment_);
   }
 };
 
+typedef std::array<HeapLocation, 2> HeapLocationPair;
+typedef std::set<HeapLocationPair> HeapLocationPairs;
+
+struct ProcessComparisonState;
+struct StateComparator;
+
 static inline
 HeapLocationPair makeHeapLocationPair(int block1, int fragment1, int block2, int fragment2)
 {
-  return simgrid::mc::HeapLocationPair{{
-    simgrid::mc::HeapLocation(block1, fragment1),
-    simgrid::mc::HeapLocation(block2, fragment2)
-  }};
+  return HeapLocationPair{{HeapLocation(block1, fragment1), HeapLocation(block2, fragment2)}};
 }
 
-struct HeapArea : public HeapLocation {
-  bool valid = false;
-  int block = 0;
-  int fragment = 0;
-  HeapArea() {}
-  HeapArea(int block)
-    : valid(true), block(block) {}
-  HeapArea(int block, int fragment = 0)
-    : valid(true), block(block), fragment(fragment) {}
+class HeapArea : public HeapLocation {
+public:
+  bool valid_ = false;
+  HeapArea() = default;
+  explicit HeapArea(int block) : valid_(true) { block_ = block; }
+  HeapArea(int block, int fragment) : valid_(true)
+  {
+    block_    = block;
+    fragment_ = fragment;
+  }
 };
 
-struct ProcessComparisonState {
+class ProcessComparisonState {
+public:
   std::vector<simgrid::mc::IgnoredHeapRegion>* to_ignore = nullptr;
   std::vector<HeapArea> equals_to;
   std::vector<simgrid::mc::Type*> types;
@@ -117,28 +72,32 @@ struct ProcessComparisonState {
   void initHeapInformation(xbt_mheap_t heap, std::vector<simgrid::mc::IgnoredHeapRegion>* i);
 };
 
+static int compare_heap_area(StateComparator& state, const void* area1, const void* area2, Snapshot* snapshot1,
+                             Snapshot* snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level);
+
 namespace {
 
 /** A hash which works with more stuff
  *
  *  It can hash pairs: the standard hash currently doesn't include this.
  */
-template<class X> struct hash : public std::hash<X> {};
+template <class X> class hash : public std::hash<X> {
+};
 
-template<class X, class Y>
-struct hash<std::pair<X,Y>> {
+template <class X, class Y> class hash<std::pair<X, Y>> {
+public:
   std::size_t operator()(std::pair<X,Y>const& x) const
   {
-    struct hash<X> h1;
-    struct hash<X> h2;
+    hash<X> h1;
+    hash<X> h2;
     return h1(x.first) ^ h2(x.second);
   }
 };
 
 }
 
-
-struct StateComparator {
+class StateComparator {
+public:
   s_xbt_mheap_t std_heap_copy;
   std::size_t heaplimit;
   std::array<ProcessComparisonState, 2> processStates;
@@ -197,8 +156,7 @@ struct StateComparator {
    */
   bool blocksEqual(int b1, int b2) const
   {
-    return this->equals_to1_(b1, 0).block == b2
-        && this->equals_to2_(b2, 0).block == b1;
+    return this->equals_to1_(b1, 0).block_ == b2 && this->equals_to2_(b2, 0).block_ == b1;
   }
 
   /** Check whether two fragments are known to be matching
@@ -211,10 +169,8 @@ struct StateComparator {
    */
   int fragmentsEqual(int b1, int f1, int b2, int f2) const
   {
-    return this->equals_to1_(b1, f1).block == b2
-        && this->equals_to1_(b1, f1).fragment == f2
-        && this->equals_to2_(b2, f2).block == b1
-        && this->equals_to2_(b2, f2).fragment == f1;
+    return this->equals_to1_(b1, f1).block_ == b2 && this->equals_to1_(b1, f1).fragment_ == f2 &&
+           this->equals_to2_(b2, f2).block_ == b1 && this->equals_to2_(b2, f2).fragment_ == f1;
   }
 
   void match_equals(HeapLocationPairs* list);
@@ -269,12 +225,12 @@ namespace mc {
 void StateComparator::match_equals(HeapLocationPairs* list)
 {
   for (auto const& pair : *list) {
-    if (pair[0].fragment != -1) {
-      this->equals_to1_(pair[0].block, pair[0].fragment) = simgrid::mc::HeapArea(pair[1].block, pair[1].fragment);
-      this->equals_to2_(pair[1].block, pair[1].fragment) = simgrid::mc::HeapArea(pair[0].block, pair[0].fragment);
+    if (pair[0].fragment_ != -1) {
+      this->equals_to1_(pair[0].block_, pair[0].fragment_) = simgrid::mc::HeapArea(pair[1].block_, pair[1].fragment_);
+      this->equals_to2_(pair[1].block_, pair[1].fragment_) = simgrid::mc::HeapArea(pair[0].block_, pair[0].fragment_);
     } else {
-      this->equals_to1_(pair[0].block, 0) = simgrid::mc::HeapArea(pair[1].block, pair[1].fragment);
-      this->equals_to2_(pair[1].block, 0) = simgrid::mc::HeapArea(pair[0].block, pair[0].fragment);
+      this->equals_to1_(pair[0].block_, 0) = simgrid::mc::HeapArea(pair[1].block_, pair[1].fragment_);
+      this->equals_to2_(pair[1].block_, 0) = simgrid::mc::HeapArea(pair[0].block_, pair[0].fragment_);
     }
   }
 }
@@ -303,59 +259,44 @@ int StateComparator::initHeapInformation(xbt_mheap_t heap1, xbt_mheap_t heap2,
 }
 
 // TODO, have a robust way to find it in O(1)
-static inline
-mc_mem_region_t MC_get_heap_region(simgrid::mc::Snapshot* snapshot)
+static inline Region* MC_get_heap_region(Snapshot* snapshot)
 {
-  for (auto& region : snapshot->snapshot_regions)
+  for (auto const& region : snapshot->snapshot_regions_)
     if (region->region_type() == simgrid::mc::RegionType::Heap)
       return region.get();
   xbt_die("No heap region");
 }
 
-static
-int mmalloc_compare_heap(
-  simgrid::mc::StateComparator& state, simgrid::mc::Snapshot* snapshot1, simgrid::mc::Snapshot* snapshot2)
+static bool mmalloc_heap_equal(simgrid::mc::StateComparator& state, simgrid::mc::Snapshot* snapshot1,
+                               simgrid::mc::Snapshot* snapshot2)
 {
   simgrid::mc::RemoteClient* process = &mc_model_checker->process();
 
-  /* Start comparison */
-  size_t i1;
-  size_t i2;
-  size_t j1;
-  size_t j2;
-  size_t k;
-  void* addr_block1;
-  void* addr_block2;
-  void* addr_frag1;
-  void* addr_frag2;
-  int nb_diff1 = 0;
-  int nb_diff2 = 0;
-  int equal;
-  int res_compare = 0;
-
   /* Check busy blocks */
-  i1 = 1;
+  size_t i1 = 1;
 
   malloc_info heapinfo_temp1;
   malloc_info heapinfo_temp2;
   malloc_info heapinfo_temp2b;
 
-  mc_mem_region_t heap_region1 = MC_get_heap_region(snapshot1);
-  mc_mem_region_t heap_region2 = MC_get_heap_region(snapshot2);
+  simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
+  simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
 
   // This is the address of std_heap->heapinfo in the application process:
   void* heapinfo_address = &((xbt_mheap_t) process->heap_address)->heapinfo;
 
   // This is in snapshot do not use them directly:
-  const malloc_info* heapinfos1 = snapshot1->read<malloc_info*>(
-    (std::uint64_t)heapinfo_address, simgrid::mc::ProcessIndexMissing);
-  const malloc_info* heapinfos2 = snapshot2->read<malloc_info*>(
-    (std::uint64_t)heapinfo_address, simgrid::mc::ProcessIndexMissing);
+  const malloc_info* heapinfos1 =
+      snapshot1->read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
+  const malloc_info* heapinfos2 =
+      snapshot2->read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
 
   while (i1 < state.heaplimit) {
 
-    const malloc_info* heapinfo1 = (const malloc_info*) MC_region_read(heap_region1, &heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info));
-    const malloc_info* heapinfo2 = (const malloc_info*) MC_region_read(heap_region2, &heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info));
+    const malloc_info* heapinfo1 =
+        (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info));
+    const malloc_info* heapinfo2 =
+        (const malloc_info*)heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info));
 
     if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) {      /* Free block */
       i1 ++;
@@ -367,75 +308,71 @@ int mmalloc_compare_heap(
       abort();
     }
 
-    addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase));
+    void* addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase));
 
     if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) {       /* Large block */
 
       if (is_stack(addr_block1)) {
-        for (k = 0; k < heapinfo1->busy_block.size; k++)
+        for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
           state.equals_to1_(i1 + k, 0) = HeapArea(i1, -1);
-        for (k = 0; k < heapinfo2->busy_block.size; k++)
+        for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
           state.equals_to2_(i1 + k, 0) = HeapArea(i1, -1);
         i1 += heapinfo1->busy_block.size;
         continue;
       }
 
-      if (state.equals_to1_(i1, 0).valid) {
+      if (state.equals_to1_(i1, 0).valid_) {
         i1++;
         continue;
       }
 
-      i2          = 1;
-      equal       = 0;
-      res_compare = 0;
+      size_t i2 = 1;
+      bool equal = false;
 
       /* Try first to associate to same block in the other heap */
-      if (heapinfo2->type == heapinfo1->type
-        && state.equals_to2_(i1, 0).valid == 0) {
-        addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
-        res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, addr_block1, addr_block2, snapshot1,
-                                        snapshot2, nullptr, nullptr, 0);
+      if (heapinfo2->type == heapinfo1->type && state.equals_to2_(i1, 0).valid_ == 0) {
+        void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+        int res_compare = compare_heap_area(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0);
         if (res_compare != 1) {
-          for (k = 1; k < heapinfo2->busy_block.size; k++)
+          for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
             state.equals_to2_(i1 + k, 0) = HeapArea(i1, -1);
-          for (k = 1; k < heapinfo1->busy_block.size; k++)
+          for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
             state.equals_to1_(i1 + k, 0) = HeapArea(i1, -1);
-          equal = 1;
+          equal = true;
           i1 += heapinfo1->busy_block.size;
         }
       }
 
       while (i2 < state.heaplimit && not equal) {
 
-        addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+        void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
 
         if (i2 == i1) {
           i2++;
           continue;
         }
 
-        const malloc_info* heapinfo2b = (const malloc_info*) MC_region_read(heap_region2, &heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info));
+        const malloc_info* heapinfo2b =
+            (const malloc_info*)heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info));
 
         if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
           i2++;
           continue;
         }
 
-        if (state.equals_to2_(i2, 0).valid) {
+        if (state.equals_to2_(i2, 0).valid_) {
           i2++;
           continue;
         }
 
-        res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing,
-            addr_block1, addr_block2, snapshot1, snapshot2,
-            nullptr, nullptr, 0);
+        int res_compare = compare_heap_area(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0);
 
         if (res_compare != 1) {
-          for (k = 1; k < heapinfo2b->busy_block.size; k++)
+          for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
             state.equals_to2_(i2 + k, 0) = HeapArea(i1, -1);
-          for (k = 1; k < heapinfo1->busy_block.size; k++)
+          for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
             state.equals_to1_(i1 + k, 0) = HeapArea(i2, -1);
-          equal = 1;
+          equal = true;
           i1 += heapinfo1->busy_block.size;
         }
 
@@ -444,44 +381,37 @@ int mmalloc_compare_heap(
 
       if (not equal) {
         XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
-        i1 = state.heaplimit + 1;
-        nb_diff1++;
-        //i1++;
+        return false;
       }
 
     } else {                    /* Fragmented block */
 
-      for (j1 = 0; j1 < (size_t) (BLOCKSIZE >> heapinfo1->type); j1++) {
+      for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
 
-        if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment */
+        if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
           continue;
 
-        if (state.equals_to1_(i1, j1).valid)
+        if (state.equals_to1_(i1, j1).valid_)
           continue;
 
-        addr_frag1 = (void*)((char*)addr_block1 + (j1 << heapinfo1->type));
+        void* addr_frag1 = (void*)((char*)addr_block1 + (j1 << heapinfo1->type));
 
-        i2 = 1;
-        equal = 0;
+        size_t i2 = 1;
+        bool equal = false;
 
-        /* Try first to associate to same fragment in the other heap */
-        if (heapinfo2->type == heapinfo1->type && not state.equals_to2_(i1, j1).valid) {
-          addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE +
-                         (char *) state.std_heap_copy.heapbase;
-          addr_frag2 =
-              (void *) ((char *) addr_block2 +
-                        (j1 << heapinfo2->type));
-          res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, addr_frag1, addr_frag2, snapshot1,
-                                          snapshot2, nullptr, nullptr, 0);
+        /* Try first to associate to same fragment_ in the other heap */
+        if (heapinfo2->type == heapinfo1->type && not state.equals_to2_(i1, j1).valid_) {
+          void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+          void* addr_frag2  = (void*)((char*)addr_block2 + (j1 << heapinfo2->type));
+          int res_compare = compare_heap_area(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0);
           if (res_compare != 1)
-            equal = 1;
+            equal = true;
         }
 
         while (i2 < state.heaplimit && not equal) {
 
-          const malloc_info* heapinfo2b = (const malloc_info*) MC_region_read(
-            heap_region2, &heapinfo_temp2b, &heapinfos2[i2],
-            sizeof(malloc_info));
+          const malloc_info* heapinfo2b =
+              (const malloc_info*)heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info));
 
           if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
             i2 ++;
@@ -499,22 +429,21 @@ int mmalloc_compare_heap(
             abort();
           }
 
-          for (j2 = 0; j2 < (size_t) (BLOCKSIZE >> heapinfo2b->type);
-               j2++) {
+          for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
 
             if (i2 == i1 && j2 == j1)
               continue;
 
-            if (state.equals_to2_(i2, j2).valid)
+            if (state.equals_to2_(i2, j2).valid_)
               continue;
 
-            addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
-            addr_frag2  = (void*)((char*)addr_block2 + (j2 << heapinfo2b->type));
+            void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+            void* addr_frag2  = (void*)((char*)addr_block2 + (j2 << heapinfo2b->type));
 
-            res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, addr_frag1, addr_frag2, snapshot2,
-                                            snapshot2, nullptr, nullptr, 0);
+            int res_compare =
+                compare_heap_area(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0);
             if (res_compare != 1) {
-              equal = 1;
+              equal = true;
               break;
             }
           }
@@ -523,12 +452,9 @@ int mmalloc_compare_heap(
         }
 
         if (not equal) {
-          XBT_DEBUG("Block %zu, fragment %zu not found (size_used = %zd, address = %p)\n", i1, j1,
+          XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
                     heapinfo1->busy_frag.frag_size[j1], addr_frag1);
-          i2 = state.heaplimit + 1;
-          i1 = state.heaplimit + 1;
-          nb_diff1++;
-          break;
+          return false;
         }
       }
 
@@ -536,58 +462,48 @@ int mmalloc_compare_heap(
     }
   }
 
-  /* All blocks/fragments are equal to another block/fragment ? */
-  size_t i = 1;
-  size_t j = 0;
-
-  for(i = 1; i < state.heaplimit; i++) {
-    const malloc_info* heapinfo1 = (const malloc_info*) MC_region_read(
-      heap_region1, &heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info));
+  /* All blocks/fragments are equal to another block/fragment_ ? */
+  for (size_t i = 1; i < state.heaplimit; i++) {
+    const malloc_info* heapinfo1 =
+        (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info));
 
     if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
-        not state.equals_to1_(i, 0).valid) {
+        not state.equals_to1_(i, 0).valid_) {
       XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
-      nb_diff1++;
+      return false;
     }
 
     if (heapinfo1->type <= 0)
       continue;
-    for (j = 0; j < (size_t) (BLOCKSIZE >> heapinfo1->type); j++)
-      if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to1_(i, j).valid) {
+    for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
+      if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to1_(i, j).valid_) {
         XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
-        nb_diff1++;
+        return false;
       }
   }
 
-  if (i1 == state.heaplimit)
-    XBT_DEBUG("Number of blocks/fragments not found in heap1: %d", nb_diff1);
-
-  for (i=1; i < state.heaplimit; i++) {
-    const malloc_info* heapinfo2 = (const malloc_info*) MC_region_read(
-      heap_region2, &heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info));
+  for (size_t i = 1; i < state.heaplimit; i++) {
+    const malloc_info* heapinfo2 =
+        (const malloc_info*)heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info));
     if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
-        not state.equals_to2_(i, 0).valid) {
+        not state.equals_to2_(i, 0).valid_) {
       XBT_DEBUG("Block %zu not found (size used = %zu)", i,
                 heapinfo2->busy_block.busy_size);
-      nb_diff2++;
+      return false;
     }
 
     if (heapinfo2->type <= 0)
       continue;
 
-    for (j = 0; j < (size_t) (BLOCKSIZE >> heapinfo2->type); j++)
-      if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to2_(i, j).valid) {
+    for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
+      if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to2_(i, j).valid_) {
         XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
           i, j, heapinfo2->busy_frag.frag_size[j]);
-        nb_diff2++;
+        return false;
       }
-
   }
 
-  if (i1 == state.heaplimit)
-    XBT_DEBUG("Number of blocks/fragments not found in heap2: %d", nb_diff2);
-
-  return nb_diff1 > 0 || nb_diff2 > 0;
+  return true;
 }
 
 /**
@@ -601,30 +517,25 @@ int mmalloc_compare_heap(
  * @param size
  * @param check_ignore
  */
-static int compare_heap_area_without_type(
-  simgrid::mc::StateComparator& state, int process_index,
-  const void *real_area1, const void *real_area2,
-  simgrid::mc::Snapshot* snapshot1,
-  simgrid::mc::Snapshot* snapshot2,
-  HeapLocationPairs* previous, int size,
-  int check_ignore)
+static bool heap_area_equal_without_type(simgrid::mc::StateComparator& state, const void* real_area1,
+                                         const void* real_area2, simgrid::mc::Snapshot* snapshot1,
+                                         simgrid::mc::Snapshot* snapshot2, HeapLocationPairs* previous, int size,
+                                         int check_ignore)
 {
   simgrid::mc::RemoteClient* process = &mc_model_checker->process();
-  mc_mem_region_t heap_region1 = MC_get_heap_region(snapshot1);
-  mc_mem_region_t heap_region2 = MC_get_heap_region(snapshot2);
+  simgrid::mc::Region* heap_region1  = MC_get_heap_region(snapshot1);
+  simgrid::mc::Region* heap_region2  = MC_get_heap_region(snapshot2);
 
   for (int i = 0; i < size; ) {
 
     if (check_ignore > 0) {
-      ssize_t ignore1 = heap_comparison_ignore_size(
-        state.processStates[0].to_ignore, (char *) real_area1 + i);
+      ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (char*)real_area1 + i);
       if (ignore1 != -1) {
-        ssize_t ignore2 = heap_comparison_ignore_size(
-          state.processStates[1].to_ignore, (char *) real_area2 + i);
+        ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (char*)real_area2 + i);
         if (ignore2 == ignore1) {
           if (ignore1 == 0) {
             check_ignore--;
-            return 0;
+            return true;
           } else {
             i = i + ignore2;
             check_ignore--;
@@ -637,10 +548,8 @@ static int compare_heap_area_without_type(
     if (MC_snapshot_region_memcmp(((char *) real_area1) + i, heap_region1, ((char *) real_area2) + i, heap_region2, 1) != 0) {
 
       int pointer_align = (i / sizeof(void *)) * sizeof(void *);
-      const void* addr_pointed1 = snapshot1->read(
-        remote((void**)((char *) real_area1 + pointer_align)), process_index);
-      const void* addr_pointed2 = snapshot2->read(
-        remote((void**)((char *) real_area2 + pointer_align)), process_index);
+      const void* addr_pointed1 = snapshot1->read(remote((void**)((char*)real_area1 + pointer_align)));
+      const void* addr_pointed2 = snapshot2->read(remote((void**)((char*)real_area2 + pointer_align)));
 
       if (process->in_maestro_stack(remote(addr_pointed1))
         && process->in_maestro_stack(remote(addr_pointed2))) {
@@ -652,23 +561,22 @@ static int compare_heap_area_without_type(
            && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1)
            && addr_pointed2 > state.std_heap_copy.heapbase
            && addr_pointed2 < mc_snapshot_get_heap_end(snapshot2)) {
-        // Both addreses are in the heap:
-        int res_compare = compare_heap_area(state ,process_index,
-          addr_pointed1, addr_pointed2,
-          snapshot1, snapshot2, previous, nullptr, 0);
+        // Both addresses are in the heap:
+        int res_compare =
+            compare_heap_area(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0);
         if (res_compare == 1)
-          return res_compare;
+          return false;
         i = pointer_align + sizeof(void *);
         continue;
       }
 
-      return 1;
+      return false;
     }
 
     i++;
   }
 
-  return 0;
+  return true;
 }
 
 /**
@@ -685,17 +593,11 @@ static int compare_heap_area_without_type(
  * @param pointer_level
  * @return               0 (same), 1 (different), -1 (unknown)
  */
-static int compare_heap_area_with_type(
-  simgrid::mc::StateComparator& state, int process_index,
-  const void *real_area1, const void *real_area2,
-  simgrid::mc::Snapshot* snapshot1,
-  simgrid::mc::Snapshot* snapshot2,
-  HeapLocationPairs* previous, simgrid::mc::Type* type,
-  int area_size, int check_ignore,
-  int pointer_level)
+static int compare_heap_area_with_type(simgrid::mc::StateComparator& state, const void* real_area1,
+                                       const void* real_area2, simgrid::mc::Snapshot* snapshot1,
+                                       simgrid::mc::Snapshot* snapshot2, HeapLocationPairs* previous,
+                                       simgrid::mc::Type* type, int area_size, int check_ignore, int pointer_level)
 {
-top:
-
   // HACK: This should not happen but in pratice, there are some
   // DW_TAG_typedef without an associated DW_AT_type:
   //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
@@ -709,189 +611,156 @@ top:
     return 0;
 
   if (check_ignore > 0) {
-    ssize_t ignore1 = heap_comparison_ignore_size(
-      state.processStates[0].to_ignore, real_area1);
-    if (ignore1 > 0
-        && heap_comparison_ignore_size(
-          state.processStates[1].to_ignore, real_area2) == ignore1)
+    ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
+    if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
       return 0;
   }
 
   simgrid::mc::Type* subtype;
   simgrid::mc::Type* subsubtype;
-  int res;
   int elm_size;
   const void* addr_pointed1;
   const void* addr_pointed2;
 
-  mc_mem_region_t heap_region1 = MC_get_heap_region(snapshot1);
-  mc_mem_region_t heap_region2 = MC_get_heap_region(snapshot2);
+  simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
+  simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
 
   switch (type->type) {
-  case DW_TAG_unspecified_type:
-    return 1;
-
-  case DW_TAG_base_type:
-    if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
-      if (real_area1 == real_area2)
-        return -1;
-      else
-        return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
-    } else {
-      if (area_size != -1 && type->byte_size != area_size)
-        return -1;
-      else
-        return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
-    }
-    break;
-
-  case DW_TAG_enumeration_type:
-    if (area_size != -1 && type->byte_size != area_size)
-      return -1;
-    return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
-
-  case DW_TAG_typedef:
-  case DW_TAG_const_type:
-  case DW_TAG_volatile_type:
-    // Poor man's TCO:
-    type = type->subtype;
-    goto top;
-
-  case DW_TAG_array_type:
-    subtype = type->subtype;
-    switch (subtype->type) {
     case DW_TAG_unspecified_type:
       return 1;
 
     case DW_TAG_base_type:
+      if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
+        if (real_area1 == real_area2)
+          return -1;
+        else
+          return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
+      } else {
+        if (area_size != -1 && type->byte_size != area_size)
+          return -1;
+        else
+          return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
+      }
+
     case DW_TAG_enumeration_type:
-    case DW_TAG_pointer_type:
-    case DW_TAG_reference_type:
-    case DW_TAG_rvalue_reference_type:
-    case DW_TAG_structure_type:
-    case DW_TAG_class_type:
-    case DW_TAG_union_type:
-      if (subtype->full_type)
-        subtype = subtype->full_type;
-      elm_size = subtype->byte_size;
-      break;
-      // TODO, just remove the type indirection?
-    case DW_TAG_const_type:
+      if (area_size != -1 && type->byte_size != area_size)
+        return -1;
+      return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
+
     case DW_TAG_typedef:
+    case DW_TAG_const_type:
     case DW_TAG_volatile_type:
-      subsubtype = subtype->subtype;
-      if (subsubtype->full_type)
-        subsubtype = subsubtype->full_type;
-      elm_size = subsubtype->byte_size;
-      break;
-    default:
-      return 0;
-      break;
-    }
-    for (int i = 0; i < type->element_count; i++) {
-      // TODO, add support for variable stride (DW_AT_byte_stride)
-      res =
-          compare_heap_area_with_type(state, process_index,
-                                      (char *) real_area1 + (i * elm_size),
-                                      (char *) real_area2 + (i * elm_size),
-                                      snapshot1, snapshot2, previous,
-                                      type->subtype, subtype->byte_size,
-                                      check_ignore, pointer_level);
-      if (res == 1)
-        return res;
-    }
-    return 0;
+      return compare_heap_area_with_type(state, real_area1, real_area2, snapshot1, snapshot2, previous, type->subtype,
+                                         area_size, check_ignore, pointer_level);
 
-  case DW_TAG_reference_type:
-  case DW_TAG_rvalue_reference_type:
-  case DW_TAG_pointer_type:
-    if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
-      addr_pointed1 = snapshot1->read(remote((void**)real_area1), process_index);
-      addr_pointed2 = snapshot2->read(remote((void**)real_area2), process_index);
-      return (addr_pointed1 != addr_pointed2);
-    }
-    pointer_level++;
-    if (pointer_level <= 1) {
-      addr_pointed1 = snapshot1->read(remote((void**)real_area1), process_index);
-      addr_pointed2 = snapshot2->read(remote((void**)real_area2), process_index);
-      if (addr_pointed1 > state.std_heap_copy.heapbase
-          && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1)
-          && addr_pointed2 > state.std_heap_copy.heapbase
-          && addr_pointed2 < mc_snapshot_get_heap_end(snapshot2))
-        return compare_heap_area(state, process_index,
-            addr_pointed1, addr_pointed2, snapshot1,
-            snapshot2, previous, type->subtype,
-            pointer_level);
-      else
-        return (addr_pointed1 != addr_pointed2);
-    }
-    for (size_t i = 0; i < (area_size / sizeof(void *)); i++) {
-      addr_pointed1 = snapshot1->read(
-        remote((void**)((char*) real_area1 + i * sizeof(void *))),
-        process_index);
-      addr_pointed2 = snapshot2->read(
-        remote((void**)((char*) real_area2 + i * sizeof(void *))),
-        process_index);
-      if (addr_pointed1 > state.std_heap_copy.heapbase
-          && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1)
-          && addr_pointed2 > state.std_heap_copy.heapbase
-          && addr_pointed2 < mc_snapshot_get_heap_end(snapshot2))
-        res =
-            compare_heap_area(state, process_index,
-              addr_pointed1, addr_pointed2, snapshot1,
-              snapshot2, previous, type->subtype,
-              pointer_level);
-      else
-        res = (addr_pointed1 != addr_pointed2);
-      if (res == 1)
-        return res;
-    }
-    return 0;
+    case DW_TAG_array_type:
+      subtype = type->subtype;
+      switch (subtype->type) {
+        case DW_TAG_unspecified_type:
+          return 1;
 
-  case DW_TAG_structure_type:
-  case DW_TAG_class_type:
-    if (type->full_type)
-      type = type->full_type;
-    if (area_size != -1 && type->byte_size != area_size) {
-      if (area_size <= type->byte_size || area_size % type->byte_size != 0)
-        return -1;
-      for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
-        int res = compare_heap_area_with_type(state, process_index,
-                    (char *) real_area1 + i * type->byte_size,
-                    (char *) real_area2 + i * type->byte_size,
-                    snapshot1, snapshot2, previous, type, -1,
-                    check_ignore, 0);
+        case DW_TAG_base_type:
+        case DW_TAG_enumeration_type:
+        case DW_TAG_pointer_type:
+        case DW_TAG_reference_type:
+        case DW_TAG_rvalue_reference_type:
+        case DW_TAG_structure_type:
+        case DW_TAG_class_type:
+        case DW_TAG_union_type:
+          if (subtype->full_type)
+            subtype = subtype->full_type;
+          elm_size  = subtype->byte_size;
+          break;
+        // TODO, just remove the type indirection?
+        case DW_TAG_const_type:
+        case DW_TAG_typedef:
+        case DW_TAG_volatile_type:
+          subsubtype = subtype->subtype;
+          if (subsubtype->full_type)
+            subsubtype = subsubtype->full_type;
+          elm_size     = subsubtype->byte_size;
+          break;
+        default:
+          return 0;
+      }
+      for (int i = 0; i < type->element_count; i++) {
+        // TODO, add support for variable stride (DW_AT_byte_stride)
+        int res = compare_heap_area_with_type(state, (char*)real_area1 + (i * elm_size),
+                                              (char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
+                                              type->subtype, subtype->byte_size, check_ignore, pointer_level);
         if (res == 1)
           return res;
       }
-    } else {
-      for(simgrid::mc::Member& member : type->members) {
-        // TODO, optimize this? (for the offset case)
-        void *real_member1 = simgrid::dwarf::resolve_member(
-          real_area1, type, &member, (simgrid::mc::AddressSpace*) snapshot1, process_index);
-        void *real_member2 = simgrid::dwarf::resolve_member(
-            real_area2, type, &member, (simgrid::mc::AddressSpace*) snapshot2, process_index);
-        int res = compare_heap_area_with_type(
-                    state, process_index, real_member1, real_member2,
-                    snapshot1, snapshot2,
-                    previous, member.type, -1,
-                    check_ignore, 0);
+      return 0;
+
+    case DW_TAG_reference_type:
+    case DW_TAG_rvalue_reference_type:
+    case DW_TAG_pointer_type:
+      if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
+        addr_pointed1 = snapshot1->read(remote((void**)real_area1));
+        addr_pointed2 = snapshot2->read(remote((void**)real_area2));
+        return (addr_pointed1 != addr_pointed2);
+      }
+      pointer_level++;
+      if (pointer_level <= 1) {
+        addr_pointed1 = snapshot1->read(remote((void**)real_area1));
+        addr_pointed2 = snapshot2->read(remote((void**)real_area2));
+        if (addr_pointed1 > state.std_heap_copy.heapbase && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1) &&
+            addr_pointed2 > state.std_heap_copy.heapbase && addr_pointed2 < mc_snapshot_get_heap_end(snapshot2))
+          return compare_heap_area(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, type->subtype,
+                                   pointer_level);
+        else
+          return (addr_pointed1 != addr_pointed2);
+      }
+      for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
+        addr_pointed1 = snapshot1->read(remote((void**)((char*)real_area1 + i * sizeof(void*))));
+        addr_pointed2 = snapshot2->read(remote((void**)((char*)real_area2 + i * sizeof(void*))));
+        int res;
+        if (addr_pointed1 > state.std_heap_copy.heapbase && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1) &&
+            addr_pointed2 > state.std_heap_copy.heapbase && addr_pointed2 < mc_snapshot_get_heap_end(snapshot2))
+          res = compare_heap_area(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, type->subtype,
+                                  pointer_level);
+        else
+          res = (addr_pointed1 != addr_pointed2);
         if (res == 1)
           return res;
       }
-    }
-    return 0;
+      return 0;
 
-  case DW_TAG_union_type:
-    return compare_heap_area_without_type(state, process_index, real_area1, real_area2,
-                                          snapshot1, snapshot2, previous,
-                                          type->byte_size, check_ignore);
+    case DW_TAG_structure_type:
+    case DW_TAG_class_type:
+      if (type->full_type)
+        type = type->full_type;
+      if (area_size != -1 && type->byte_size != area_size) {
+        if (area_size <= type->byte_size || area_size % type->byte_size != 0)
+          return -1;
+        for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
+          int res = compare_heap_area_with_type(state, (char*)real_area1 + i * type->byte_size,
+                                                (char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
+                                                type, -1, check_ignore, 0);
+          if (res == 1)
+            return res;
+        }
+        } else {
+          for (simgrid::mc::Member& member : type->members) {
+            // TODO, optimize this? (for the offset case)
+            void* real_member1 =
+                simgrid::dwarf::resolve_member(real_area1, type, &member, (simgrid::mc::AddressSpace*)snapshot1);
+            void* real_member2 =
+                simgrid::dwarf::resolve_member(real_area2, type, &member, (simgrid::mc::AddressSpace*)snapshot2);
+            int res = compare_heap_area_with_type(state, real_member1, real_member2, snapshot1, snapshot2, previous,
+                                                  member.type, -1, check_ignore, 0);
+            if (res == 1)
+              return res;
+          }
+        }
+        return 0;
 
-  default:
-    return 0;
+    case DW_TAG_union_type:
+      return not heap_area_equal_without_type(state, real_area1, real_area2, snapshot1, snapshot2, previous,
+                                              type->byte_size, check_ignore);
   }
-
-  xbt_die("Unreachable");
+  return 0;
 }
 
 /** Infer the type of a part of the block from the type of the block
@@ -904,9 +773,8 @@ top:
  * @param  area_size
  * @return                    DWARF type ID for given offset
  */
-static simgrid::mc::Type* get_offset_type(void *real_base_address, simgrid::mc::Type* type,
-                                 int offset, int area_size,
-                                 simgrid::mc::Snapshot* snapshot, int process_index)
+static simgrid::mc::Type* get_offset_type(void* real_base_address, simgrid::mc::Type* type, int offset, int area_size,
+                                          simgrid::mc::Snapshot* snapshot)
 {
 
   // Beginning of the block, the infered variable type if the type of the block:
@@ -926,13 +794,13 @@ static simgrid::mc::Type* get_offset_type(void *real_base_address, simgrid::mc::
         return nullptr;
     }
 
-    for(simgrid::mc::Member& member : type->members) {
+    for (simgrid::mc::Member& member : type->members) {
       if (member.has_offset_location()) {
         // We have the offset, use it directly (shortcut):
         if (member.offset() == offset)
           return member.type;
       } else {
-        void* real_member = simgrid::dwarf::resolve_member(real_base_address, type, &member, snapshot, process_index);
+        void* real_member = simgrid::dwarf::resolve_member(real_base_address, type, &member, snapshot);
         if ((char*)real_member - (char*)real_base_address == offset)
           return member.type;
       }
@@ -957,28 +825,17 @@ static simgrid::mc::Type* get_offset_type(void *real_base_address, simgrid::mc::
  * @param pointer_level
  * @return 0 (same), 1 (different), -1
  */
-static
-int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
-                      const void *area1, const void *area2,
-                      simgrid::mc::Snapshot* snapshot1,
-                      simgrid::mc::Snapshot* snapshot2,
-                      HeapLocationPairs* previous,
-                      simgrid::mc::Type* type, int pointer_level)
+static int compare_heap_area(simgrid::mc::StateComparator& state, const void* area1, const void* area2,
+                             simgrid::mc::Snapshot* snapshot1, simgrid::mc::Snapshot* snapshot2,
+                             HeapLocationPairs* previous, simgrid::mc::Type* type, int pointer_level)
 {
   simgrid::mc::RemoteClient* process = &mc_model_checker->process();
 
-  int res_compare;
   ssize_t block1;
-  ssize_t frag1;
   ssize_t block2;
-  ssize_t frag2;
   ssize_t size;
   int check_ignore = 0;
 
-  void* real_addr_block1;
-  void* real_addr_block2;
-  void* real_addr_frag1;
-  void* real_addr_frag2;
   int type_size = -1;
   int offset1   = 0;
   int offset2   = 0;
@@ -993,10 +850,11 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
   // This is the address of std_heap->heapinfo in the application process:
   void* heapinfo_address = &((xbt_mheap_t) process->heap_address)->heapinfo;
 
-  const malloc_info* heapinfos1 = snapshot1->read(remote((const malloc_info**)heapinfo_address), process_index);
-  const malloc_info* heapinfos2 = snapshot2->read(remote((const malloc_info**)heapinfo_address), process_index);
+  const malloc_info* heapinfos1 = snapshot1->read(remote((const malloc_info**)heapinfo_address));
+  const malloc_info* heapinfos2 = snapshot2->read(remote((const malloc_info**)heapinfo_address));
 
-  malloc_info heapinfo_temp1, heapinfo_temp2;
+  malloc_info heapinfo_temp1;
+  malloc_info heapinfo_temp2;
 
   simgrid::mc::HeapLocationPairs current;
   if (previous == nullptr) {
@@ -1024,8 +882,8 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
   }
 
   // Process address of the block:
-  real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
-  real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+  void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+  void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
 
   if (type) {
     if (type->full_type)
@@ -1044,13 +902,13 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
 
   }
 
-  mc_mem_region_t heap_region1 = MC_get_heap_region(snapshot1);
-  mc_mem_region_t heap_region2 = MC_get_heap_region(snapshot2);
+  simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
+  simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
 
-  const malloc_info* heapinfo1 = (const malloc_info*) MC_region_read(
-    heap_region1, &heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info));
-  const malloc_info* heapinfo2 = (const malloc_info*) MC_region_read(
-    heap_region2, &heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info));
+  const malloc_info* heapinfo1 =
+      (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info));
+  const malloc_info* heapinfo2 =
+      (const malloc_info*)heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info));
 
   if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
     && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
@@ -1065,23 +923,19 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
 
     // TODO, lookup variable type from block type as done for fragmented blocks
 
-    offset1 = (char*)area1 - (char*)real_addr_block1;
-    offset2 = (char*)area2 - (char*)real_addr_block2;
-
-    if (state.equals_to1_(block1, 0).valid && state.equals_to2_(block2, 0).valid && state.blocksEqual(block1, block2)) {
+    if (state.equals_to1_(block1, 0).valid_ && state.equals_to2_(block2, 0).valid_ &&
+        state.blocksEqual(block1, block2)) {
       if (match_pairs)
         state.match_equals(previous);
       return 0;
     }
 
-    if (type_size != -1) {
-      if (type_size != (ssize_t) heapinfo1->busy_block.busy_size
-          && type_size != (ssize_t)   heapinfo2->busy_block.busy_size
-          && (type->name.empty() || type->name == "struct s_smx_context")) {
-        if (match_pairs)
-          state.match_equals(previous);
-        return -1;
-      }
+    if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
+        type_size != (ssize_t)heapinfo2->busy_block.busy_size &&
+        (type->name.empty() || type->name == "struct s_smx_context")) {
+      if (match_pairs)
+        state.match_equals(previous);
+      return -1;
     }
 
     if (heapinfo1->busy_block.size != heapinfo2->busy_block.size)
@@ -1110,9 +964,6 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
       return 0;
     }
 
-    frag1 = -1;
-    frag2 = -1;
-
     if (heapinfo1->busy_block.ignore > 0
         && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
       check_ignore = heapinfo1->busy_block.ignore;
@@ -1120,12 +971,12 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
   } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) {      /* Fragmented block */
 
     // Fragment number:
-    frag1 = ((uintptr_t)(ADDR2UINT(area1) % (BLOCKSIZE))) >> heapinfo1->type;
-    frag2 = ((uintptr_t)(ADDR2UINT(area2) % (BLOCKSIZE))) >> heapinfo2->type;
+    ssize_t frag1 = ((uintptr_t)(ADDR2UINT(area1) % (BLOCKSIZE))) >> heapinfo1->type;
+    ssize_t frag2 = ((uintptr_t)(ADDR2UINT(area2) % (BLOCKSIZE))) >> heapinfo2->type;
 
-    // Process address of the fragment:
-    real_addr_frag1 = (void*)((char*)real_addr_block1 + (frag1 << heapinfo1->type));
-    real_addr_frag2 = (void*)((char*)real_addr_block2 + (frag2 << heapinfo2->type));
+    // Process address of the fragment_:
+    void* real_addr_frag1 = (void*)((char*)real_addr_block1 + (frag1 << heapinfo1->type));
+    void* real_addr_frag2 = (void*)((char*)real_addr_block2 + (frag2 << heapinfo2->type));
 
     // Check the size of the fragments against the size of the type:
     if (type_size != -1) {
@@ -1144,12 +995,11 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
     }
 
     // Check if the blocks are already matched together:
-    if (state.equals_to1_(block1, frag1).valid && state.equals_to2_(block2, frag2).valid) {
-      if (offset1==offset2 && state.fragmentsEqual(block1, frag1, block2, frag2)) {
-        if (match_pairs)
-          state.match_equals(previous);
-        return 0;
-      }
+    if (state.equals_to1_(block1, frag1).valid_ && state.equals_to2_(block2, frag2).valid_ && offset1 == offset2 &&
+        state.fragmentsEqual(block1, frag1, block2, frag2)) {
+      if (match_pairs)
+        state.match_equals(previous);
+      return 0;
     }
     // Compare the size of both fragments:
     if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
@@ -1161,11 +1011,11 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
         return 1;
     }
 
-    // Size of the fragment:
+    // Size of the fragment_:
     size = heapinfo1->busy_frag.frag_size[frag1];
 
     // Remember (basic) type inference.
-    // The current data structure only allows us to do this for the whole fragment.
+    // The current data structure only allows us to do this for the whole fragment_.
     if (type != nullptr && area1 == real_addr_frag1)
       state.types1_(block1, frag1) = type;
     if (type != nullptr && area2 == real_addr_frag2)
@@ -1173,8 +1023,7 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
 
     // The type of the variable is already known:
     if (type) {
-      new_type1 = type;
-      new_type2 = type;
+      new_type1 = new_type2 = type;
     }
     // Type inference from the block type.
     else if (state.types1_(block1, frag1) != nullptr || state.types2_(block2, frag2) != nullptr) {
@@ -1183,20 +1032,14 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
       offset2 = (char*)area2 - (char*)real_addr_frag2;
 
       if (state.types1_(block1, frag1) != nullptr && state.types2_(block2, frag2) != nullptr) {
-        new_type1 =
-            get_offset_type(real_addr_frag1, state.types1_(block1, frag1), offset1, size, snapshot1, process_index);
-        new_type2 =
-            get_offset_type(real_addr_frag2, state.types2_(block2, frag2), offset1, size, snapshot2, process_index);
+        new_type1 = get_offset_type(real_addr_frag1, state.types1_(block1, frag1), offset1, size, snapshot1);
+        new_type2 = get_offset_type(real_addr_frag2, state.types2_(block2, frag2), offset1, size, snapshot2);
       } else if (state.types1_(block1, frag1) != nullptr) {
-        new_type1 =
-            get_offset_type(real_addr_frag1, state.types1_(block1, frag1), offset1, size, snapshot1, process_index);
-        new_type2 =
-            get_offset_type(real_addr_frag2, state.types1_(block1, frag1), offset2, size, snapshot2, process_index);
+        new_type1 = get_offset_type(real_addr_frag1, state.types1_(block1, frag1), offset1, size, snapshot1);
+        new_type2 = get_offset_type(real_addr_frag2, state.types1_(block1, frag1), offset2, size, snapshot2);
       } else if (state.types2_(block2, frag2) != nullptr) {
-        new_type1 =
-            get_offset_type(real_addr_frag1, state.types2_(block2, frag2), offset1, size, snapshot1, process_index);
-        new_type2 =
-            get_offset_type(real_addr_frag2, state.types2_(block2, frag2), offset2, size, snapshot2, process_index);
+        new_type1 = get_offset_type(real_addr_frag1, state.types2_(block2, frag2), offset1, size, snapshot1);
+        new_type2 = get_offset_type(real_addr_frag2, state.types2_(block2, frag2), offset2, size, snapshot2);
       } else {
         if (match_pairs)
           state.match_equals(previous);
@@ -1249,12 +1092,13 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
 
 
   /* Start comparison */
+  int res_compare;
   if (type)
-    res_compare = compare_heap_area_with_type(state, process_index, area1, area2, snapshot1, snapshot2, previous, type,
-                                              size, check_ignore, pointer_level);
+    res_compare = compare_heap_area_with_type(state, area1, area2, snapshot1, snapshot2, previous, type, size,
+                                              check_ignore, pointer_level);
   else
-    res_compare = compare_heap_area_without_type(state, process_index, area1, area2, snapshot1, snapshot2, previous,
-                                                 size, check_ignore);
+    res_compare =
+        not heap_area_equal_without_type(state, area1, area2, snapshot1, snapshot2, previous, size, check_ignore);
 
   if (res_compare == 1)
     return res_compare;
@@ -1270,10 +1114,9 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index,
 /************************** Snapshot comparison *******************************/
 /******************************************************************************/
 
-static int compare_areas_with_type(simgrid::mc::StateComparator& state,
-                                   int process_index,
-                                   void* real_area1, simgrid::mc::Snapshot* snapshot1, mc_mem_region_t region1,
-                                   void* real_area2, simgrid::mc::Snapshot* snapshot2, mc_mem_region_t region2,
+static int compare_areas_with_type(simgrid::mc::StateComparator& state, void* real_area1,
+                                   simgrid::mc::Snapshot* snapshot1, simgrid::mc::Region* region1, void* real_area2,
+                                   simgrid::mc::Snapshot* snapshot2, simgrid::mc::Region* region2,
                                    simgrid::mc::Type* type, int pointer_level)
 {
   simgrid::mc::RemoteClient* process = &mc_model_checker->process();
@@ -1284,182 +1127,135 @@ static int compare_areas_with_type(simgrid::mc::StateComparator& state,
   int i;
   int res;
 
-  top:
+  xbt_assert(type != nullptr);
   switch (type->type) {
-  case DW_TAG_unspecified_type:
-    return 1;
-
-  case DW_TAG_base_type:
-  case DW_TAG_enumeration_type:
-  case DW_TAG_union_type:
-    return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
-  case DW_TAG_typedef:
-  case DW_TAG_volatile_type:
-  case DW_TAG_const_type:
-    // Poor man's TCO:
-    type = type->subtype;
-    goto top;
-  case DW_TAG_array_type:
-    subtype = type->subtype;
-    switch (subtype->type) {
     case DW_TAG_unspecified_type:
       return 1;
 
     case DW_TAG_base_type:
     case DW_TAG_enumeration_type:
-    case DW_TAG_pointer_type:
-    case DW_TAG_reference_type:
-    case DW_TAG_rvalue_reference_type:
-    case DW_TAG_structure_type:
-    case DW_TAG_class_type:
     case DW_TAG_union_type:
-      if (subtype->full_type)
-        subtype = subtype->full_type;
-      elm_size = subtype->byte_size;
-      break;
-    case DW_TAG_const_type:
+      return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
     case DW_TAG_typedef:
     case DW_TAG_volatile_type:
-      subsubtype = subtype->subtype;
-      if (subsubtype->full_type)
-        subsubtype = subsubtype->full_type;
-      elm_size = subsubtype->byte_size;
-      break;
-    default:
-      return 0;
+    case DW_TAG_const_type:
+      return compare_areas_with_type(state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
+                                     type->subtype, pointer_level);
+    case DW_TAG_array_type:
+      subtype = type->subtype;
+      switch (subtype->type) {
+        case DW_TAG_unspecified_type:
+          return 1;
+
+        case DW_TAG_base_type:
+        case DW_TAG_enumeration_type:
+        case DW_TAG_pointer_type:
+        case DW_TAG_reference_type:
+        case DW_TAG_rvalue_reference_type:
+        case DW_TAG_structure_type:
+        case DW_TAG_class_type:
+        case DW_TAG_union_type:
+          if (subtype->full_type)
+            subtype = subtype->full_type;
+          elm_size  = subtype->byte_size;
+          break;
+        case DW_TAG_const_type:
+        case DW_TAG_typedef:
+        case DW_TAG_volatile_type:
+          subsubtype = subtype->subtype;
+          if (subsubtype->full_type)
+            subsubtype = subsubtype->full_type;
+          elm_size     = subsubtype->byte_size;
+          break;
+        default:
+          return 0;
+      }
+      for (i = 0; i < type->element_count; i++) {
+        size_t off = i * elm_size;
+        res = compare_areas_with_type(state, (char*)real_area1 + off, snapshot1, region1, (char*)real_area2 + off,
+                                      snapshot2, region2, type->subtype, pointer_level);
+        if (res == 1)
+          return res;
+      }
       break;
-    }
-    for (i = 0; i < type->element_count; i++) {
-      size_t off = i * elm_size;
-      res = compare_areas_with_type(state, process_index,
-            (char*) real_area1 + off, snapshot1, region1,
-            (char*) real_area2 + off, snapshot2, region2,
-            type->subtype, pointer_level);
-      if (res == 1)
-        return res;
-    }
-    break;
-  case DW_TAG_pointer_type:
-  case DW_TAG_reference_type:
-  case DW_TAG_rvalue_reference_type:
-  {
-    void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
-    void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
+    case DW_TAG_pointer_type:
+    case DW_TAG_reference_type:
+    case DW_TAG_rvalue_reference_type: {
+      void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
+      void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
 
-    if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
-      return (addr_pointed1 != addr_pointed2);
-    if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
-      return 0;
-    if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
-      return 1;
-    if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
-      return 0;
+      if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
+        return (addr_pointed1 != addr_pointed2);
+      if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
+        return 0;
+      if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
+        return 1;
+      if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
+        return 0;
 
-    pointer_level++;
+      pointer_level++;
 
       // Some cases are not handled here:
-      // * the pointers lead to different areas (one to the heap, the other to the RW segment ...);
-      // * a pointer leads to the read-only segment of the current object;
-      // * a pointer lead to a different ELF object.
+      // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
+      // * a pointer leads to the read-only segment of the current object
+      // * a pointer lead to a different ELF object
 
-      if (addr_pointed1 > process->heap_address
-          && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1)) {
+      if (addr_pointed1 > process->heap_address && addr_pointed1 < mc_snapshot_get_heap_end(snapshot1)) {
         if (not(addr_pointed2 > process->heap_address && addr_pointed2 < mc_snapshot_get_heap_end(snapshot2)))
           return 1;
         // The pointers are both in the heap:
-        return simgrid::mc::compare_heap_area(state,
-          process_index, addr_pointed1, addr_pointed2, snapshot1,
-          snapshot2, nullptr, type->subtype, pointer_level);
-      }
+        return simgrid::mc::compare_heap_area(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, nullptr,
+                                              type->subtype, pointer_level);
 
-      // The pointers are both in the current object R/W segment:
-      else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
+      } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
+        // The pointers are both in the current object R/W segment:
         if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
           return 1;
         if (not type->type_id)
           return (addr_pointed1 != addr_pointed2);
         else
-          return compare_areas_with_type(state, process_index,
-                                         addr_pointed1, snapshot1, region1,
-                                         addr_pointed2, snapshot2, region2,
+          return compare_areas_with_type(state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2, region2,
                                          type->subtype, pointer_level);
-      }
+      } else {
 
-      // TODO, We do not handle very well the case where
-      // it belongs to a different (non-heap) region from the current one.
+        // TODO, We do not handle very well the case where
+        // it belongs to a different (non-heap) region from the current one.
 
-      else
         return (addr_pointed1 != addr_pointed2);
-
-    break;
-  }
-  case DW_TAG_structure_type:
-  case DW_TAG_class_type:
-    for(simgrid::mc::Member& member : type->members) {
-      void *member1 = simgrid::dwarf::resolve_member(
-        real_area1, type, &member, snapshot1, process_index);
-      void *member2 = simgrid::dwarf::resolve_member(
-        real_area2, type, &member, snapshot2, process_index);
-      mc_mem_region_t subregion1 = mc_get_region_hinted(member1, snapshot1, process_index, region1);
-      mc_mem_region_t subregion2 = mc_get_region_hinted(member2, snapshot2, process_index, region2);
-      res =
-          compare_areas_with_type(state, process_index,
-                                  member1, snapshot1, subregion1,
-                                  member2, snapshot2, subregion2,
-                                  member.type, pointer_level);
-      if (res == 1)
-        return res;
+      }
     }
-    break;
-  case DW_TAG_subroutine_type:
-    return -1;
-    break;
-  default:
-    XBT_VERB("Unknown case: %d", type->type);
-    break;
+    case DW_TAG_structure_type:
+    case DW_TAG_class_type:
+      for (simgrid::mc::Member& member : type->members) {
+        void* member1                   = simgrid::dwarf::resolve_member(real_area1, type, &member, snapshot1);
+        void* member2                   = simgrid::dwarf::resolve_member(real_area2, type, &member, snapshot2);
+        simgrid::mc::Region* subregion1 = snapshot1->get_region(member1, region1); // region1 is hinted
+        simgrid::mc::Region* subregion2 = snapshot2->get_region(member2, region2); // region2 is hinted
+        res = compare_areas_with_type(state, member1, snapshot1, subregion1, member2, snapshot2, subregion2,
+                                      member.type, pointer_level);
+        if (res == 1)
+          return res;
+      }
+      break;
+    case DW_TAG_subroutine_type:
+      return -1;
+    default:
+      XBT_VERB("Unknown case: %d", type->type);
+      break;
   }
 
   return 0;
 }
 
-static int compare_global_variables(
-  simgrid::mc::StateComparator& state,
-  simgrid::mc::ObjectInformation* object_info,
-  int process_index,
-  mc_mem_region_t r1, mc_mem_region_t r2,
-  simgrid::mc::Snapshot* snapshot1, simgrid::mc::Snapshot* snapshot2)
+static bool global_variables_equal(simgrid::mc::StateComparator& state, simgrid::mc::ObjectInformation* object_info,
+                                   simgrid::mc::Region* r1, simgrid::mc::Region* r2, simgrid::mc::Snapshot* snapshot1,
+                                   simgrid::mc::Snapshot* snapshot2)
 {
   xbt_assert(r1 && r2, "Missing region.");
 
-#if HAVE_SMPI
-  if (r1->storage_type() == simgrid::mc::StorageType::Privatized) {
-    xbt_assert(process_index >= 0);
-    if (r2->storage_type() != simgrid::mc::StorageType::Privatized)
-      return 1;
-
-    size_t process_count = MC_smpi_process_count();
-    xbt_assert(process_count == r1->privatized_data().size()
-      && process_count == r2->privatized_data().size());
-
-    // Compare the global variables separately for each simulates process:
-    for (size_t process_index = 0; process_index < process_count; process_index++) {
-      if (compare_global_variables(state,
-          object_info, process_index,
-          &r1->privatized_data()[process_index],
-          &r2->privatized_data()[process_index],
-          snapshot1, snapshot2))
-        return 1;
-    }
-    return 0;
-  }
-#else
-  xbt_assert(r1->storage_type() != simgrid::mc::StorageType::Privatized);
-#endif
-  xbt_assert(r2->storage_type() != simgrid::mc::StorageType::Privatized);
-
   std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
 
-  for (simgrid::mc::Variable& current_var : variables) {
+  for (simgrid::mc::Variable const& current_var : variables) {
 
     // If the variable is not in this object, skip it:
     // We do not expect to find a pointer to something which is not reachable
@@ -1469,71 +1265,52 @@ static int compare_global_variables(
       continue;
 
     simgrid::mc::Type* bvariable_type = current_var.type;
-    int res = compare_areas_with_type(state, process_index,
-                                (char *) current_var.address, snapshot1, r1,
-                                (char *) current_var.address, snapshot2, r2,
-                                bvariable_type, 0);
+    int res = compare_areas_with_type(state, (char*)current_var.address, snapshot1, r1, (char*)current_var.address,
+                                      snapshot2, r2, bvariable_type, 0);
     if (res == 1) {
       XBT_VERB("Global variable %s (%p) is different between snapshots",
                current_var.name.c_str(),
                (char *) current_var.address);
-      return 1;
+      return false;
     }
   }
 
-  return 0;
+  return true;
 }
 
-static int compare_local_variables(simgrid::mc::StateComparator& state,
-                                   int process_index,
-                                   simgrid::mc::Snapshot* snapshot1,
-                                   simgrid::mc::Snapshot* snapshot2,
-                                   mc_snapshot_stack_t stack1,
-                                   mc_snapshot_stack_t stack2)
+static bool local_variables_equal(simgrid::mc::StateComparator& state, simgrid::mc::Snapshot* snapshot1,
+                                  simgrid::mc::Snapshot* snapshot2, mc_snapshot_stack_t stack1,
+                                  mc_snapshot_stack_t stack2)
 {
   if (stack1->local_variables.size() != stack2->local_variables.size()) {
     XBT_VERB("Different number of local variables");
-    return 1;
+    return false;
   }
 
-    unsigned int cursor = 0;
-    local_variable_t current_var1, current_var2;
-    while (cursor < stack1->local_variables.size()) {
-      current_var1 = &stack1->local_variables[cursor];
-      current_var2 = &stack1->local_variables[cursor];
-      if (current_var1->name != current_var2->name
-          || current_var1->subprogram != current_var2->subprogram
-          || current_var1->ip != current_var2->ip) {
-        // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
-        XBT_VERB
-            ("Different name of variable (%s - %s) "
-             "or frame (%s - %s) or ip (%lu - %lu)",
-             current_var1->name.c_str(),
-             current_var2->name.c_str(),
-             current_var1->subprogram->name.c_str(),
-             current_var2->subprogram->name.c_str(),
-             current_var1->ip, current_var2->ip);
-        return 1;
-      }
+  for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
+    local_variable_t current_var1 = &stack1->local_variables[cursor];
+    local_variable_t current_var2 = &stack2->local_variables[cursor];
+    if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
+        current_var1->ip != current_var2->ip) {
       // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
+      XBT_VERB("Different name of variable (%s - %s) "
+               "or frame (%s - %s) or ip (%lu - %lu)",
+               current_var1->name.c_str(), current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
+               current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
+      return false;
+    }
 
-        simgrid::mc::Type* subtype = current_var1->type;
-        int res                    = compare_areas_with_type(
-            state, process_index, current_var1->address, snapshot1,
-            mc_get_snapshot_region(current_var1->address, snapshot1, process_index), current_var2->address, snapshot2,
-            mc_get_snapshot_region(current_var2->address, snapshot2, process_index), subtype, 0);
-
-        if (res == 1) {
-          // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
-          XBT_VERB("Local variable %s (%p - %p) in frame %s "
-                   "is different between snapshots",
-                   current_var1->name.c_str(), current_var1->address, current_var2->address,
-                   current_var1->subprogram->name.c_str());
-          return res;
-      }
-      cursor++;
+    if (compare_areas_with_type(state, current_var1->address, snapshot1, snapshot1->get_region(current_var1->address),
+                                current_var2->address, snapshot2, snapshot2->get_region(current_var2->address),
+                                current_var1->type, 0) == 1) {
+      XBT_VERB("Local variable %s (%p - %p) in frame %s "
+               "is different between snapshots",
+               current_var1->name.c_str(), current_var1->address, current_var2->address,
+               current_var1->subprogram->name.c_str());
+      return false;
     }
-    return 0;
+    }
+    return true;
 }
 
 namespace simgrid {
@@ -1541,182 +1318,96 @@ namespace mc {
 
 static std::unique_ptr<simgrid::mc::StateComparator> state_comparator;
 
-int snapshot_compare(int num1, simgrid::mc::Snapshot* s1, int num2, simgrid::mc::Snapshot* s2)
+bool snapshot_equal(Snapshot* s1, Snapshot* s2)
 {
   // TODO, make this a field of ModelChecker or something similar
-
   if (state_comparator == nullptr)
-    state_comparator = std::unique_ptr<StateComparator>(new StateComparator());
+    state_comparator.reset(new StateComparator());
   else
     state_comparator->clear();
 
-  simgrid::mc::RemoteClient* process = &mc_model_checker->process();
-
-  int errors = 0;
+  RemoteClient* process = &mc_model_checker->process();
 
-  int hash_result = 0;
-  if (_sg_mc_hash) {
-    hash_result = (s1->hash != s2->hash);
-    if (hash_result) {
-      XBT_VERB("(%d - %d) Different hash: 0x%" PRIx64 "--0x%" PRIx64, num1, num2, s1->hash, s2->hash);
-#ifndef MC_DEBUG
-      return 1;
-#endif
+  if (s1->hash_ != s2->hash_) {
+    XBT_VERB("(%d - %d) Different hash: 0x%" PRIx64 "--0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_,
+             s2->hash_);
+    return false;
     } else
-      XBT_VERB("(%d - %d) Same hash: 0x%" PRIx64, num1, num2, s1->hash);
-  }
+      XBT_VERB("(%d - %d) Same hash: 0x%" PRIx64, s1->num_state_, s2->num_state_, s1->hash_);
 
   /* Compare enabled processes */
-  if (s1->enabled_processes != s2->enabled_processes) {
-    XBT_VERB("(%d - %d) Different amount of enabled processes", num1, num2);
-    return 1;
+  if (s1->enabled_processes_ != s2->enabled_processes_) {
+    XBT_VERB("(%d - %d) Different amount of enabled processes", s1->num_state_, s2->num_state_);
+    return false;
   }
 
   /* Compare size of stacks */
-  int is_diff = 0;
-  for (unsigned long i = 0; i < s1->stacks.size(); i++) {
-    size_t size_used1 = s1->stack_sizes[i];
-    size_t size_used2 = s2->stack_sizes[i];
+  for (unsigned long i = 0; i < s1->stacks_.size(); i++) {
+    size_t size_used1 = s1->stack_sizes_[i];
+    size_t size_used2 = s2->stack_sizes_[i];
     if (size_used1 != size_used2) {
-#ifdef MC_DEBUG
-      XBT_DEBUG("(%d - %d) Different size used in stacks: %zu - %zu", num1, num2, size_used1, size_used2);
-      errors++;
-      is_diff = 1;
-#else
-#ifdef MC_VERBOSE
-      XBT_VERB("(%d - %d) Different size used in stacks: %zu - %zu", num1, num2, size_used1, size_used2);
-#endif
-      return 1;
-#endif
+      XBT_VERB("(%d - %d) Different size used in stacks: %zu - %zu", s1->num_state_, s2->num_state_, size_used1,
+               size_used2);
+      return false;
     }
   }
-  if (is_diff) // do not proceed if there is any stacks that don't match
-    return 1;
 
   /* Init heap information used in heap comparison algorithm */
-  xbt_mheap_t heap1 = (xbt_mheap_t)s1->read_bytes(
-    alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
-    remote(process->heap_address),
-    simgrid::mc::ProcessIndexMissing, simgrid::mc::ReadOptions::lazy());
-  xbt_mheap_t heap2 = (xbt_mheap_t)s2->read_bytes(
-    alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
-    remote(process->heap_address),
-    simgrid::mc::ProcessIndexMissing, simgrid::mc::ReadOptions::lazy());
-  int res_init = state_comparator->initHeapInformation(heap1, heap2, &s1->to_ignore, &s2->to_ignore);
+  xbt_mheap_t heap1 = (xbt_mheap_t)s1->read_bytes(alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
+                                                  remote(process->heap_address), simgrid::mc::ReadOptions::lazy());
+  xbt_mheap_t heap2 = (xbt_mheap_t)s2->read_bytes(alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
+                                                  remote(process->heap_address), simgrid::mc::ReadOptions::lazy());
+  int res_init = state_comparator->initHeapInformation(heap1, heap2, &s1->to_ignore_, &s2->to_ignore_);
 
   if (res_init == -1) {
-#ifdef MC_DEBUG
-    XBT_DEBUG("(%d - %d) Different heap information", num1, num2);
-    errors++;
-#else
-#ifdef MC_VERBOSE
-    XBT_VERB("(%d - %d) Different heap information", num1, num2);
-#endif
-
-    return 1;
-#endif
+    XBT_VERB("(%d - %d) Different heap information", s1->num_state_, s2->num_state_);
+    return false;
   }
 
   /* Stacks comparison */
-  int diff_local = 0;
-  for (unsigned int cursor = 0; cursor < s1->stacks.size(); cursor++) {
-    mc_snapshot_stack_t stack1 = &s1->stacks[cursor];
-    mc_snapshot_stack_t stack2 = &s2->stacks[cursor];
-
-    if (stack1->process_index != stack2->process_index) {
-      diff_local = 1;
-      XBT_DEBUG("(%d - %d) Stacks with different process index (%i vs %i)", num1, num2,
-        stack1->process_index, stack2->process_index);
-    }
-    else diff_local = compare_local_variables(*state_comparator,
-      stack1->process_index, s1, s2, stack1, stack2);
-    if (diff_local > 0) {
-#ifdef MC_DEBUG
-      XBT_DEBUG("(%d - %d) Different local variables between stacks %d", num1,
-                num2, cursor + 1);
-      errors++;
-#else
-
-#ifdef MC_VERBOSE
-      XBT_VERB("(%d - %d) Different local variables between stacks %d", num1,
-               num2, cursor + 1);
-#endif
+  for (unsigned int cursor = 0; cursor < s1->stacks_.size(); cursor++) {
+    mc_snapshot_stack_t stack1 = &s1->stacks_[cursor];
+    mc_snapshot_stack_t stack2 = &s2->stacks_[cursor];
 
-      return 1;
-#endif
+    if (not local_variables_equal(*state_comparator, s1, s2, stack1, stack2)) {
+      XBT_VERB("(%d - %d) Different local variables between stacks %u", s1->num_state_, s2->num_state_, cursor + 1);
+      return false;
     }
   }
 
-  size_t regions_count = s1->snapshot_regions.size();
-  // TODO, raise a difference instead?
-  xbt_assert(regions_count == s2->snapshot_regions.size());
+  size_t regions_count = s1->snapshot_regions_.size();
+  if (regions_count != s2->snapshot_regions_.size())
+    return false;
 
   for (size_t k = 0; k != regions_count; ++k) {
-    mc_mem_region_t region1 = s1->snapshot_regions[k].get();
-    mc_mem_region_t region2 = s2->snapshot_regions[k].get();
+    Region* region1 = s1->snapshot_regions_[k].get();
+    Region* region2 = s2->snapshot_regions_[k].get();
 
     // Preconditions:
-    if (region1->region_type() != simgrid::mc::RegionType::Data)
+    if (region1->region_type() != RegionType::Data)
       continue;
 
     xbt_assert(region1->region_type() == region2->region_type());
     xbt_assert(region1->object_info() == region2->object_info());
     xbt_assert(region1->object_info());
 
-    std::string const& name = region1->object_info()->file_name;
-
     /* Compare global variables */
-    if (compare_global_variables(*state_comparator, region1->object_info(), simgrid::mc::ProcessIndexDisabled, region1,
-                                 region2, s1, s2)) {
-
-#ifdef MC_DEBUG
-      XBT_DEBUG("(%d - %d) Different global variables in %s",
-        num1, num2, name.c_str());
-      errors++;
-#else
-#ifdef MC_VERBOSE
-      XBT_VERB("(%d - %d) Different global variables in %s",
-        num1, num2, name.c_str());
-#endif
-
-      return 1;
-#endif
+    if (not global_variables_equal(*state_comparator, region1->object_info(), region1, region2, s1, s2)) {
+      std::string const& name = region1->object_info()->file_name;
+      XBT_VERB("(%d - %d) Different global variables in %s", s1->num_state_, s2->num_state_, name.c_str());
+      return false;
     }
   }
 
   /* Compare heap */
-  if (simgrid::mc::mmalloc_compare_heap(*state_comparator, s1, s2) > 0) {
-
-#ifdef MC_DEBUG
-    XBT_DEBUG("(%d - %d) Different heap (mmalloc_compare)", num1, num2);
-    errors++;
-#else
-
-#ifdef MC_VERBOSE
-    XBT_VERB("(%d - %d) Different heap (mmalloc_compare)", num1, num2);
-#endif
-    return 1;
-#endif
+  if (not mmalloc_heap_equal(*state_comparator, s1, s2)) {
+    XBT_VERB("(%d - %d) Different heap (mmalloc_compare)", s1->num_state_, s2->num_state_);
+    return false;
   }
 
-#ifdef MC_VERBOSE
-  if (errors || hash_result)
-    XBT_VERB("(%d - %d) Difference found", num1, num2);
-  else
-    XBT_VERB("(%d - %d) No difference found", num1, num2);
-#endif
-
-#if defined(MC_DEBUG) && defined(MC_VERBOSE)
-  if (_sg_mc_hash) {
-    // * false positive SHOULD be avoided.
-    // * There MUST not be any false negative.
-
-    XBT_VERB("(%d - %d) State equality hash test is %s %s", num1, num2,
-             (hash_result != 0) == (errors != 0) ? "true" : "false", not hash_result ? "positive" : "negative");
-  }
-#endif
+    XBT_VERB("(%d - %d) No difference found", s1->num_state_, s2->num_state_);
 
-  return errors > 0 || hash_result;
+    return true;
 }
 
 }