diff --git a/compiler/global/linearity.ml b/compiler/global/linearity.ml
index 127ff30..2f9b4a5 100644
--- a/compiler/global/linearity.ml
+++ b/compiler/global/linearity.ml
@@ -15,6 +15,12 @@ module LinearitySet = Set.Make(struct
   let compare = compare
 end)
 
+module LocationEnv =
+    Map.Make(struct
+      type t = linearity_var
+      let compare = compare
+    end)
+
 (** Returns a linearity object from a linearity list. *)
 let prod = function
   | [l] -> l
@@ -41,6 +47,15 @@ let rec is_not_linear = function
   | Ltuple l -> List.for_all is_not_linear l
   | _ -> false
 
+let rec is_linear = function
+  | Lat _ | Lvar _ -> true
+  | Ltuple l -> List.exists is_linear l
+  | _ -> false
+
+let location_name = function
+  | Lat r | Lvar r -> r
+  | _ -> assert false
+
 exception UnifyFailed
 
 (** Unifies lin with expected_lin and returns the result
diff --git a/compiler/heptagon/analysis/linear_typing.ml b/compiler/heptagon/analysis/linear_typing.ml
index beb1879..00ed4e5 100644
--- a/compiler/heptagon/analysis/linear_typing.ml
+++ b/compiler/heptagon/analysis/linear_typing.ml
@@ -567,7 +567,6 @@ and expect_iterator env loc it expected_lin inputs_lins outputs_lins e_list = ma
     let inputs_lins = subst_lin m inputs_lins in
 
     (* Then guess linearities of other vars to get expected_lin *)
-      Format.eprintf "%d == %d@." (List.length inputs_lins) (List.length e_list);
     let _, coll_exp = extract_lin_exp inputs_lins e_list in
     let collect_list = List.map (collect_exp env) coll_exp in
     let names_list =
diff --git a/compiler/main/mls2obc.ml b/compiler/main/mls2obc.ml
index b8d5f17..2856dff 100644
--- a/compiler/main/mls2obc.ml
+++ b/compiler/main/mls2obc.ml
@@ -166,8 +166,8 @@ let rec translate_pat map = function
         pat_list []
 
 let translate_var_dec l =
-  let one_var { Minils.v_ident = x; Minils.v_type = t; v_loc = loc } =
-    mk_var_dec ~loc:loc x t
+  let one_var { Minils.v_ident = x; Minils.v_type = t; Minils.v_linearity = lin; v_loc = loc } =
+    mk_var_dec ~loc:loc ~linearity:lin x t
   in
   List.map one_var l
 
diff --git a/compiler/minils/analysis/interference.ml b/compiler/minils/analysis/interference.ml
index 1f6cc26..691d5ff 100644
--- a/compiler/minils/analysis/interference.ml
+++ b/compiler/minils/analysis/interference.ml
@@ -3,7 +3,9 @@ open Types
 open Clocks
 open Signature
 open Minils
+open Linearity
 open Interference_graph
+open Containers
 open Printf
 
 let print_interference_graphs = true
@@ -80,6 +82,12 @@ module InterfRead = struct
   let def eq =
     vars_pat IvarSet.empty eq.eq_lhs
 
+  let rec nth_var_from_pat j pat =
+    match j, pat with
+      | 0, Evarpat x -> x
+      | n, Etuplepat l -> nth_var_from_pat 0 (List.nth l n)
+      | _, _ -> assert false
+
   let read_exp e =
     let funs = { Mls_mapfold.defaults with
       Mls_mapfold.exp = read_exp;
@@ -95,6 +103,7 @@ end
 module World = struct
   let vds = ref Env.empty
   let memories = ref IvarSet.empty
+  let igs = ref []
 
   let init f =
     (* build vds cache *)
@@ -104,6 +113,7 @@ module World = struct
     let env = build Env.empty f.n_input in
     let env = build env f.n_output in
     let env = build env f.n_local in
+      igs := [];
       vds := env;
     (* build the set of memories *)
       let mems = Mls_utils.node_memory_vars f in
@@ -136,8 +146,6 @@ module World = struct
   let is_memory x =
     IvarSet.mem (Ivar x) !memories
 
-  let igs = ref []
-
   let node_for_ivar iv =
     let rec _node_for_ivar igs iv =
       match igs with
@@ -179,6 +187,7 @@ let add_affinity_link_from_ivar = by_ivar () add_affinity_link
 let add_same_value_link_from_name = by_name () add_affinity_link
 let add_same_value_link_from_ivar = by_ivar () add_affinity_link
 let coalesce_from_name = by_name () coalesce
+let coalesce_from_ivar = by_ivar () coalesce
 let have_same_value_from_name = by_name false have_same_value
 
 let remove_from_ivar iv =
@@ -322,7 +331,7 @@ let add_interferences live_vars =
   List.iter (fun (_, vars) -> add_interferences_from_list false vars) live_vars
 
 let spill_inputs f =
-  let spilled_inp = (*List.filter is_linear*) f.n_input in
+  let spilled_inp = List.filter (fun vd -> not (is_linear vd.v_linearity)) f.n_input in
   let spilled_inp = List.fold_left
     (fun s vd -> IvarSet.add (Ivar vd.v_ident) s) IvarSet.empty spilled_inp in
     IvarSet.iter remove_from_ivar (all_ivars_set spilled_inp)
@@ -356,6 +365,53 @@ let add_records_field_interferences () =
 
 
 
+(** Coalesce the nodes corresponding to all semilinear variables
+    with the same location. *)
+let coalesce_linear_vars () =
+  let coalesce_one_var _ vd memlocs =
+    if World.is_optimized_ty vd.v_type then
+      (match vd.v_linearity with
+        | Ltop -> memlocs
+        | Lat r ->
+            if LocationEnv.mem r memlocs then (
+              coalesce_from_name vd.v_ident (LocationEnv.find r memlocs);
+              memlocs
+            ) else
+              LocationEnv.add r vd.v_ident memlocs
+        | _ -> assert false)
+    else
+      memlocs
+  in
+    ignore (Env.fold coalesce_one_var !World.vds LocationEnv.empty)
+
+let find_targeting f =
+  let find_output outputs_lins (acc,i) l =
+    let idx = Misc.index (fun l1 -> l = l1) outputs_lins in
+      if idx >= 0 then
+        (i, idx)::acc, i+1
+      else
+        acc, i+1
+  in
+  let desc = Modules.find_value f in
+  let inputs_lins = linearities_of_arg_list desc.node_inputs in
+  let outputs_lins = linearities_of_arg_list desc.node_outputs in
+  let acc, _ = List.fold_left (find_output outputs_lins) ([], 0) inputs_lins in
+    acc
+
+(** Coalesces the nodes corresponding to the inputs (given by e_list)
+    and the outputs (given by the pattern pat) of a node
+    with the given targeting. *)
+let apply_targeting targeting e_list pat =
+  let coalesce_targeting inputs i j =
+    let invar = InterfRead.ivar_of_extvalue (List.nth inputs i) in
+    let outvar = InterfRead.nth_var_from_pat j pat in
+      coalesce_from_ivar invar (Ivar outvar)
+  in
+     List.iter (fun (i,j) -> coalesce_targeting e_list i j) targeting
+
+
+
+
 (** [process_eq igs eq] adds to the interference graphs igs
     the links corresponding to the equation. Interferences
     corresponding to live vars sets are already added by build_interf_graph.
@@ -363,9 +419,9 @@ let add_records_field_interferences () =
 let process_eq ({ eq_lhs = pat; eq_rhs = e } as eq) =
   (** Other cases*)
   match pat, e.e_desc with
-  (*  | Eapp ({ a_op = (Efun f | Enode f) }, e_list, _) ->
-      let targeting = (find_value f).node_targeting in
-        apply_targeting igs targeting e_list pat eq *)
+    | _, Eapp ({ a_op = (Efun f | Enode f) }, e_list, _) ->
+      let targeting = find_targeting f in
+        apply_targeting targeting e_list pat
     | _, Eiterator(Imap, { a_op = Enode _ | Efun _ }, _, _, w_list, _) ->
       let invars = InterfRead.ivars_of_extvalues w_list in
       let outvars = IvarSet.elements (InterfRead.def eq) in
@@ -407,7 +463,7 @@ let build_interf_graph f =
   (** Build live vars sets for each equation *)
   let live_vars = compute_live_vars eqs in
     (* Coalesce linear variables *)
-    (*coalesce_linear_vars igs vds;*)
+    coalesce_linear_vars ();
     (** Other cases*)
     List.iter process_eq f.n_equs;
     (* Add interferences from live vars set*)
diff --git a/compiler/obc/control.ml b/compiler/obc/control.ml
index 3f18218..39eb6a1 100644
--- a/compiler/obc/control.ml
+++ b/compiler/obc/control.ml
@@ -14,8 +14,75 @@ open Misc
 open Obc
 open Obc_utils
 open Clocks
+open Signature
 open Obc_mapfold
 
+let appears_in_exp, appears_in_lhs =
+  let lhsdesc _ (x, acc) ld = match ld with
+    | Lvar y -> ld, (x, acc or (x=y))
+    | Lmem y -> ld, (x, acc or (x=y))
+    | _ -> raise Errors.Fallback
+  in
+  let funs = { Obc_mapfold.defaults with lhsdesc = lhsdesc } in
+  let appears_in_exp x e =
+    let _, (_, acc) = exp_it funs (x, false) e in
+      acc
+    in
+  let appears_in_lhs x l =
+    let _, (_, acc) = lhs_it funs (x, false) l in
+      acc
+  in
+    appears_in_exp, appears_in_lhs
+
+let used_vars e =
+  let add x acc = if List.mem x acc then acc else x::acc in
+  let lhsdesc funs acc ld = match ld with
+    | Lvar y -> ld, add y acc
+    | Lmem y -> ld, add y acc
+    | _ -> raise Errors.Fallback
+  in
+  let funs = { Obc_mapfold.defaults with lhsdesc = lhsdesc } in
+  let _, vars = Obc_mapfold.exp_it funs [] e in
+    vars
+
+
+let rec find_obj o j = match j with
+  | [] -> assert false
+  | obj::j ->
+    if o = obj.o_ident then
+      Modules.find_value obj.o_class
+    else
+      find_obj o j
+
+let rec is_modified_by_call x args e_list = match args, e_list with
+  | [], [] -> false
+  | a::args, e::e_list ->
+    if Linearity.is_linear a.a_linearity && appears_in_exp x e then
+      true
+    else
+      is_modified_by_call x args e_list
+  | _, _ -> assert false
+
+let is_modified_handlers j x handlers =
+  let act _ acc a = match a with
+    | Aassgn(l, _) -> a, acc or (appears_in_lhs x l)
+    | Acall (name_list, o, Mstep, e_list) ->
+        (* first, check if e is one of the output of the function*)
+        if List.exists (appears_in_lhs x) name_list then
+          a, true
+        else (
+          let sig_info = find_obj (obj_ref_name o) j in
+            a, acc or (is_modified_by_call x sig_info.node_inputs e_list)
+        )
+    | _ -> raise Errors.Fallback
+  in
+  let funs = { Obc_mapfold.defaults with act = act } in
+    List.exists (fun (_, b) -> snd (block_it funs false b)) handlers
+
+let is_modified_handlers j e handlers =
+  let vars = used_vars e in
+    List.exists (fun x -> is_modified_handlers j x handlers) vars
+
 let fuse_blocks b1 b2 =
   { b1 with b_locals = b1.b_locals @ b2.b_locals;
       b_body = b1.b_body @ b2.b_body }
@@ -25,7 +92,7 @@ let rec find c = function
   | (c1, s1) :: h  ->
       if c = c1 then s1, h else let s, h = find c h in s, (c1, s1) :: h
 
-let rec joinlist l =
+let rec joinlist j l =
     match l with
       | [] -> []
       | [s1] -> [s1]
@@ -33,24 +100,31 @@ let rec joinlist l =
           match s1, s2 with
             | Acase(e1, h1),
               Acase(e2, h2) when e1.e_desc = e2.e_desc ->
-                joinlist ((Acase(e1, joinhandlers h1 h2))::l)
-            | s1, s2 -> s1::(joinlist (s2::l))
+                if is_modified_handlers j e1 h1 then
+                  s1::(joinlist j (s2::l))
+                else
+                  joinlist j ((Acase(e1, joinhandlers j h1 h2))::l)
+            | s1, s2 -> s1::(joinlist j (s2::l))
 
-and join_block b =
-  { b with b_body = joinlist b.b_body }
+and join_block j b =
+  { b with b_body = joinlist j b.b_body }
 
-and joinhandlers h1 h2 =
+and joinhandlers j h1 h2 =
   match h1 with
     | [] -> h2
     | (c1, s1) :: h1' ->
         let s1', h2' =
           try let s2, h2'' = find c1 h2 in fuse_blocks s1 s2, h2''
           with Not_found -> s1, h2 in
-        (c1, join_block s1') :: joinhandlers h1' h2'
+        (c1, join_block j s1') :: joinhandlers j h1' h2'
 
-let block funs acc b =
-  { b with b_body = joinlist b.b_body }, acc
+let block _ j b =
+  { b with b_body = joinlist j b.b_body }, j
+
+let class_def funs acc cd =
+  let cd, _ = Obc_mapfold.class_def funs cd.cd_objs cd in
+    cd, acc
 
 let program p =
-  let p, _ = program_it { defaults with block = block } () p in
+  let p, _ = program_it { defaults with class_def = class_def; block = block } [] p in
   p
diff --git a/compiler/obc/obc.ml b/compiler/obc/obc.ml
index 24ebcf8..f240f4c 100644
--- a/compiler/obc/obc.ml
+++ b/compiler/obc/obc.ml
@@ -15,6 +15,7 @@ open Misc
 open Names
 open Idents
 open Types
+open Linearity
 open Signature
 open Location
 
@@ -80,6 +81,7 @@ and block =
 and var_dec =
     { v_ident : var_ident;
       v_type : ty;
+      v_linearity : linearity;
       v_mutable : bool;
       v_loc : location }
 
diff --git a/compiler/obc/obc_utils.ml b/compiler/obc/obc_utils.ml
index 1914d19..f5430f7 100644
--- a/compiler/obc/obc_utils.ml
+++ b/compiler/obc/obc_utils.ml
@@ -12,12 +12,13 @@ open Idents
 open Location
 open Misc
 open Types
+open Linearity
 open Obc
 open Obc_mapfold
 open Global_mapfold
 
-let mk_var_dec ?(loc=no_location) ?(mut=false) ident ty =
-  { v_ident = ident; v_type = ty; v_mutable = mut; v_loc = loc }
+let mk_var_dec ?(loc=no_location) ?(linearity = Ltop) ?(mut=false) ident ty =
+  { v_ident = ident; v_type = ty; v_linearity = linearity; v_mutable = mut; v_loc = loc }
 
 let mk_exp ?(loc=no_location) ty desc =
   { e_desc = desc; e_ty = ty; e_loc = loc }
diff --git a/compiler/obc/transformations/memalloc_apply.ml b/compiler/obc/transformations/memalloc_apply.ml
index 495e3e0..f7dde8b 100644
--- a/compiler/obc/transformations/memalloc_apply.ml
+++ b/compiler/obc/transformations/memalloc_apply.ml
@@ -1,10 +1,17 @@
 open Types
 open Idents
+open Linearity
 open Obc
 open Obc_utils
 open Obc_mapfold
 open Interference_graph
 
+module LinListEnv =
+    Containers.ListMap(struct
+      type t = linearity_var
+      let compare = compare
+    end)
+
 let rec ivar_of_pat l = match l.pat_desc with
   | Lvar x -> Ivar x
   | Lfield(l, f) -> Ifield (ivar_of_pat l, f)
@@ -108,6 +115,22 @@ let var_decs _ (env, mutables) vds =
   in
     List.fold_right var_dec vds [], (env, mutables)
 
+
+let add_other_vars md cd =
+  let add_one (env, ty_env) vd =
+    if is_linear vd.v_linearity && not (Interference.World.is_optimized_ty vd.v_type) then
+      let r = location_name vd.v_linearity in
+      let env = LinListEnv.add_element r (Ivar vd.v_ident) env in
+      let ty_env = LocationEnv.add r vd.v_type ty_env in
+        env, ty_env
+    else
+      env, ty_env
+  in
+  let envs = List.fold_left add_one (LinListEnv.empty, LocationEnv.empty) md.m_inputs in
+  let envs = List.fold_left add_one envs md.m_outputs in
+  let env, ty_env = List.fold_left add_one envs cd.cd_mems in
+    LinListEnv.fold (fun r x acc -> (LocationEnv.find r ty_env, x)::acc) env []
+
 let class_def funs acc cd =
   (* find the substitution and apply it to the body of the class *)
   let ivars_of_vds vds = List.map (fun vd -> Ivar vd.v_ident) vds in
@@ -115,7 +138,9 @@ let class_def funs acc cd =
   let inputs = ivars_of_vds md.m_inputs in
   let outputs = ivars_of_vds md.m_outputs in
   let mems = ivars_of_vds cd.cd_mems in
-  let env, mutables = memalloc_subst_map inputs outputs mems cd.cd_mem_alloc in
+  (*add linear variables not taken into account by memory allocation*)
+  let mem_alloc = (add_other_vars md cd) @ cd.cd_mem_alloc in
+  let env, mutables = memalloc_subst_map inputs outputs mems mem_alloc in
   let cd, _ = Obc_mapfold.class_def funs (env, mutables) cd in
     cd, acc
 
diff --git a/compiler/utilities/containers.ml b/compiler/utilities/containers.ml
new file mode 100644
index 0000000..26a47bd
--- /dev/null
+++ b/compiler/utilities/containers.ml
@@ -0,0 +1,17 @@
+
+module ListMap (Ord:Map.OrderedType) =
+struct
+  include Map.Make(Ord)
+
+  let add_element k v m =
+    try
+      add k (v::(find k m)) m
+    with
+      | Not_found -> add k [v] m
+
+  let add_elements k vl m =
+    try
+      add k (vl @ (find k m)) m
+    with
+      | Not_found -> add k vl m
+end
diff --git a/compiler/utilities/minils/dcoloring.ml b/compiler/utilities/minils/dcoloring.ml
index a1244e0..9481ad0 100644
--- a/compiler/utilities/minils/dcoloring.ml
+++ b/compiler/utilities/minils/dcoloring.ml
@@ -1,4 +1,5 @@
 open Interference_graph
+open Containers
 
 (** Coloring*)
 let no_color = 0
diff --git a/compiler/utilities/minils/interference_graph.ml b/compiler/utilities/minils/interference_graph.ml
index 394724e..6ceadd0 100644
--- a/compiler/utilities/minils/interference_graph.ml
+++ b/compiler/utilities/minils/interference_graph.ml
@@ -9,23 +9,6 @@ type ivar =
     | Ivar of Idents.var_ident
     | Ifield of ivar * Names.field_name
 
-module ListMap (Ord:Map.OrderedType) =
-struct
-  include Map.Make(Ord)
-
-  let add_element k v m =
-    try
-      add k (v::(find k m)) m
-    with
-      | Not_found -> add k [v] m
-
-  let add_elements k vl m =
-    try
-      add k (vl @ (find k m)) m
-    with
-      | Not_found -> add k vl m
-end
-
 module IvarEnv =
     Map.Make (struct
       type t = ivar
diff --git a/compiler/utilities/misc.ml b/compiler/utilities/misc.ml
index 2d6376f..03e6464 100644
--- a/compiler/utilities/misc.ml
+++ b/compiler/utilities/misc.ml
@@ -257,3 +257,12 @@ let rec iter_couple f l = match l with
 (** [iter_couple_2 f l1 l2] calls f for all x in [l1] and y in [l2].  *)
 let iter_couple_2 f l1 l2 =
   List.iter (fun v1 -> List.iter (f v1) l2) l1
+
+(** [index p l] returns the idx of the first element in l
+    that satisfies predicate p.*)
+let index p l =
+  let rec aux i = function
+    | [] -> -1
+    | v::l -> if p v then i else aux (i+1) l
+  in
+    aux 0 l
diff --git a/compiler/utilities/misc.mli b/compiler/utilities/misc.mli
index ce808d0..b7e5f95 100644
--- a/compiler/utilities/misc.mli
+++ b/compiler/utilities/misc.mli
@@ -81,6 +81,9 @@ val fold_righti : (int -> 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
 val iter_couple : ('a -> 'a -> unit) -> 'a list -> unit
 (** [iter_couple_2 f l1 l2] calls f for all x in [l1] and y in [l2].  *)
 val iter_couple_2 : ('a -> 'a -> unit) -> 'a list -> 'a list -> unit
+(** [index p l] returns the idx of the first element in l
+    that satisfies predicate p.*)
+val index : ('a -> bool) -> 'a list -> int
 
 (** Functions to decompose a list into a tuple *)
 val assert_empty : 'a list -> unit