Refactor reg and label creation

1 files changed, 31 insertions, 30 deletions

diff --git a/src/eurm.ml b/src/eurm.ml
index cc81aef..5cb487b 100644
--- a/src/eurm.ml
+++ b/src/eurm.ml
@@ -34,15 +34,16 @@ let build_initial_state eurmcmds =
     | EqPredicate(r1, r2, _) | GEqPredicate(r1, r2, _) | GTPredicate(r1, r2, _)
     | LEqPredicate(r1, r2, _) | LTPredicate(r1, r2, _) -> max r1 r2
     | _ -> 0
-  in {
-    max_reg = List.fold_left (fun acc instr -> max acc (max_reg_of_instr instr)) 0 eurmcmds;
-    label_count = List.fold_left (fun acc instr -> acc + (match instr with | Label(_) -> 1 | _ -> 0)) 0 eurmcmds
-  }
+  in
+  { max_reg = List.fold_left (fun acc instr -> max acc (max_reg_of_instr instr)) 0 eurmcmds;
+    label_count = List.fold_left (fun acc instr -> acc + (match instr with | Label(_) -> 1 | _ -> 0)) 0 eurmcmds }
 
-let add_reg_label state new_regs new_labels = {
-  max_reg = state.max_reg + new_regs;
-  label_count = state.label_count + new_labels
-}
+let add_reg_label state new_regs new_labels =
+  { max_reg = state.max_reg + new_regs;
+    label_count = state.label_count + new_labels }
+
+let make_reg state offset = state.max_reg + offset
+let make_label state offset = string_of_int (state.label_count + offset)
 
 let rec apply_transform transform_func state = function
   | [] -> [], state
@@ -54,29 +55,29 @@ let rec apply_transform transform_func state = function
 let compile_stage1 eurmcmds state =
   let transform state = function
     | Dec(r) ->
-      let new_reg = state.max_reg + 1
+      let new_reg = make_reg state 1
       in [ Zero(new_reg); Inc(new_reg); Sub(r, new_reg) ],
          add_reg_label state 1 0
 
     | GEqPredicate(r1, r2, l) ->
-      let new_reg = state.max_reg + 1
+      let new_reg = make_reg state 1
       in [ Copy(new_reg, r1); Inc(new_reg); GTPredicate(new_reg, r2, l) ],
          add_reg_label state 1 0
 
     | LEqPredicate(r1, r2, l) ->
-      let new_reg = state.max_reg + 1
+      let new_reg = make_reg state 1
       in [ Copy(new_reg, r2); Inc(new_reg); GTPredicate(new_reg, r1, l) ],
          add_reg_label state 1 0
 
     | Mult(r1, r2) ->
-      let ctr_reg = state.max_reg + 1 and res_reg = state.max_reg + 2
-      and start_label = string_of_int (state.label_count + 1) and end_label = string_of_int (state.label_count + 2)
+      let ctr_reg = make_reg state 1 and res_reg = make_reg state 2
+      and start_label = make_label state 1 and end_label = make_label state 2
       in [ Zero(ctr_reg); Zero(res_reg); Label(start_label); EqPredicate(ctr_reg, r2, end_label);
            Add(res_reg, r1); Inc(ctr_reg); Goto(start_label); Label(end_label); Copy(r1, res_reg) ],
          add_reg_label state 2 2
 
     | ZeroPredicate(r, l) ->
-      let new_reg = state.max_reg + 1
+      let new_reg = make_reg state 1
       in [ Zero(new_reg); EqPredicate(r, new_reg, l) ],
          add_reg_label state 1 0
 
@@ -88,23 +89,23 @@ let compile_stage1 eurmcmds state =
 let compile_stage2 eurmcmds state =
   let transform state = function
     | Add(r1, r2) ->
-      let ctr_reg = state.max_reg + 1
-      and start_label = string_of_int (state.label_count + 1) and end_label = string_of_int (state.label_count + 2)
+      let ctr_reg = make_reg state 1
+      and start_label = make_label state 1 and end_label = make_label state 2
       in [ Zero(ctr_reg); Label(start_label); EqPredicate(ctr_reg, r2, end_label);
            Inc(r1); Inc(ctr_reg); Goto(start_label); Label(end_label) ],
          add_reg_label state 1 2
 
     | GTPredicate(r1, r2, l) ->
-      let aux_reg = state.max_reg + 1
-      and start_label = string_of_int (state.label_count + 1) and end_label = string_of_int (state.label_count + 2)
+      let aux_reg = make_reg state 1
+      and start_label = make_label state 1 and end_label = make_label state 2
       in [ Zero(aux_reg); Label(start_label); EqPredicate(aux_reg, r1, end_label); EqPredicate(aux_reg, r2, l);
            Inc(aux_reg); Goto(start_label); Label(end_label) ],
          add_reg_label state 1 2
 
     | Sub(r1, r2) ->
-      let diff_reg = state.max_reg + 1 and aux1_reg = state.max_reg + 2 and aux2_reg = state.max_reg + 3
-      and start_label = string_of_int (state.label_count + 1) and end_label = string_of_int (state.label_count + 2)
-      and error_label = string_of_int (state.label_count + 3)
+      let diff_reg = make_reg state 1 and aux1_reg = make_reg state 2 and aux2_reg = make_reg state 3
+      and start_label = make_label state 1 and end_label = make_label state 2
+      and error_label = make_label state 3
       in [ Zero(diff_reg); Copy(aux1_reg, r1); Copy(aux2_reg, r2); Label(start_label);
            EqPredicate(aux1_reg, r2, error_label); EqPredicate(aux2_reg, r1, end_label);
            Inc(diff_reg); Inc(aux1_reg); Inc(aux2_reg); Goto(start_label);
@@ -119,7 +120,7 @@ let compile_stage2 eurmcmds state =
 let compile_stage3 eurmcmds state =
   let transform state = function
     | Goto(lbl) ->
-      let dummy_reg = state.max_reg + 1
+      let dummy_reg = make_reg state 1
       in [ Zero(dummy_reg); EqPredicate(dummy_reg, dummy_reg, lbl) ],
          add_reg_label state 1 0
     | any -> [ any ], state
@@ -131,14 +132,14 @@ let compile_stage4 eurmcmds state =
   in let build_label_table =
        List.iteri (fun lineo cmd -> match cmd with | Label(lbl) -> Hashtbl.add label_table lbl lineo | _ -> ())
   in let transform state = function
-    | Inc(r) -> [ URMSucc(r) ], state
-    | Zero(r) -> [ URMZero(r) ], state
-    | Copy(r1, r2) -> [ URMCopy(r1, r2) ], state
-    | EqPredicate(r1, r2, lbl) -> [ URMJump(r1, r2, Hashtbl.find label_table lbl) ], state
-    | Label(_) ->
-      let dummy_reg = state.max_reg + 1
-      in [ URMZero(dummy_reg) ], add_reg_label state 1 0
-    | _ -> failwith "Invalid_argument"
+      | Inc(r) -> [ URMSucc(r) ], state
+      | Zero(r) -> [ URMZero(r) ], state
+      | Copy(r1, r2) -> [ URMCopy(r1, r2) ], state
+      | EqPredicate(r1, r2, lbl) -> [ URMJump(r1, r2, Hashtbl.find label_table lbl) ], state
+      | Label(_) ->
+        let dummy_reg = make_reg state 1
+        in [ URMZero(dummy_reg) ], add_reg_label state 1 0
+      | _ -> failwith "Invalid_argument"
   in build_label_table eurmcmds; apply_transform (transform) state eurmcmds
 
 let urm_from_eurm eurmcmds =