From 5341108ec6ba9465497c590679f35e8bef0c7b3f Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Wed, 25 Jan 2017 13:48:43 +0100
Subject: dialyzer: Optimize evaluation of complex code

Improve the evaluation of long lists of constraints.
---
 lib/dialyzer/src/dialyzer_typesig.erl | 37 +++++++++++++++++++++++++++--------
 1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/lib/dialyzer/src/dialyzer_typesig.erl b/lib/dialyzer/src/dialyzer_typesig.erl
index a9ebac6c8b..a7b55d1d79 100644
--- a/lib/dialyzer/src/dialyzer_typesig.erl
+++ b/lib/dialyzer/src/dialyzer_typesig.erl
@@ -2,7 +2,7 @@
 %%-----------------------------------------------------------------------
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2006-2016. All Rights Reserved.
+%% Copyright Ericsson AB 2006-2017. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -2105,6 +2105,12 @@ v2_solve_disj([I|Is], [C|Cs], I, Map0, V2State0, UL, MapL, Eval, Uneval,
   end;
 v2_solve_disj([], [], _I, _Map, V2State, UL, MapL, Eval, Uneval, Failed) ->
   {ok, V2State, lists:reverse(Eval), UL, MapL, lists:reverse(Uneval), Failed};
+v2_solve_disj(every_i, Cs, I, Map, V2State, UL, MapL, Eval, Uneval, Failed) ->
+  NewIs = case Cs of
+            [] -> [];
+            _ -> [I|every_i]
+          end,
+  v2_solve_disj(NewIs, Cs, I, Map, V2State, UL, MapL, Eval, Uneval, Failed);
 v2_solve_disj(Is, [C|Cs], I, Map, V2State, UL, MapL, Eval, Uneval0, Failed) ->
   Uneval = [{I,C#constraint_list.id} ||
              not is_failed_list(C, V2State)] ++ Uneval0,
@@ -2176,7 +2182,7 @@ v2_solve_conj([I|Is], [Cs|Tail], I, Map0, Conj, IsFlat, V2State0,
       M = lists:keydelete(I, 1, vars_per_child(U, Masks)),
       {V2State2, NewF0} = save_updated_vars_list(AllCs, M, V2State1),
       {NewF, F} = lists:splitwith(fun(J) -> J < I end, NewF0),
-      Is1 = lists:umerge(Is, F),
+      Is1 = umerge_mask(Is, F),
       NewFs = [NewF|NewFs0],
       v2_solve_conj(Is1, Tail, I+1, Map, Conj, IsFlat, V2State2,
                     [U|UL], NewFs, VarsUp, LastMap, LastFlags)
@@ -2198,6 +2204,14 @@ v2_solve_conj([], _Cs, _I, Map, Conj, IsFlat, V2State, UL, NewFs, VarsUp,
       v2_solve_conj(NewFlags, Cs, 1, Map, Conj, IsFlat, V2State,
                     [], [], [U|VarsUp], Map, NewFlags)
   end;
+v2_solve_conj(every_i, Cs, I, Map, Conj, IsFlat, V2State, UL, NewFs, VarsUp,
+              LastMap, LastFlags) ->
+  NewIs = case Cs of
+            [] -> [];
+            _ -> [I|every_i]
+          end,
+  v2_solve_conj(NewIs, Cs, I, Map, Conj, IsFlat, V2State, UL, NewFs, VarsUp,
+                LastMap, LastFlags);
 v2_solve_conj(Is, [_|Tail], I, Map, Conj, IsFlat, V2State, UL, NewFs, VarsUp,
              LastMap, LastFlags) ->
   v2_solve_conj(Is, Tail, I+1, Map, Conj, IsFlat, V2State, UL, NewFs, VarsUp,
@@ -2214,7 +2228,12 @@ report_detected_loop(_) ->
 add_mask_to_flags(Flags, [Im|M], I, L) when I > Im ->
   add_mask_to_flags(Flags, M, I, [Im|L]);
 add_mask_to_flags(Flags, [_|M], _I, L) ->
-  {lists:umerge(M, Flags), lists:reverse(L)}.
+  {umerge_mask(Flags, M), lists:reverse(L)}.
+
+umerge_mask(every_i, _F) ->
+  every_i;
+umerge_mask(Is, F) ->
+  lists:umerge(Is, F).
 
 get_mask(V, Masks) ->
   case maps:find(V, Masks) of
@@ -2228,7 +2247,7 @@ get_flags(#v2_state{constr_data = ConData}=V2State0, C) ->
     error ->
       ?debug("get_flags Id=~w Flags=all ~w\n", [Id, length(Cs)]),
       V2State = V2State0#v2_state{constr_data = maps:put(Id, {[],[]}, ConData)},
-      {V2State, lists:seq(1, length(Cs))};
+      {V2State, every_i};
     {ok, failed} ->
       {V2State0, failed_list};
     {ok, {Part,U}} when U =/= [] ->
@@ -2989,7 +3008,7 @@ find_constraint_deps([Type|Tail], Acc) ->
   NewAcc = [[t_var_name(D) || D <- t_collect_vars(Type)]|Acc],
   find_constraint_deps(Tail, NewAcc);
 find_constraint_deps([], Acc) ->
-  lists:flatten(Acc).
+  lists:append(Acc).
 
 mk_constraint_1(Lhs, eq, Rhs, Deps) when Lhs < Rhs ->
   #constraint{lhs = Lhs, op = eq, rhs = Rhs, deps = Deps};
@@ -3097,8 +3116,8 @@ expand_to_conjunctions(#constraint_list{type = disj, list = List}) ->
   List1 = [C || C <- List, is_simple_constraint(C)],
   %% Just an assert.
   [] = [C || #constraint{} = C <- List1],
-  Expanded = lists:flatten([expand_to_conjunctions(C)
-			    || #constraint_list{} = C <- List]),
+  Expanded = lists:append([expand_to_conjunctions(C)
+                           || #constraint_list{} = C <- List]),
   ReturnList = Expanded ++ List1,
   if length(ReturnList) > ?DISJ_NORM_FORM_LIMIT -> throw(too_many_disj);
      true -> ReturnList
@@ -3123,8 +3142,10 @@ calculate_deps(List) ->
 calculate_deps([H|Tail], Acc) ->
   Deps = get_deps(H),
   calculate_deps(Tail, [Deps|Acc]);
+calculate_deps([], []) -> [];
+calculate_deps([], [L]) -> L;
 calculate_deps([], Acc) ->
-  ordsets:from_list(lists:flatten(Acc)).
+  lists:umerge(Acc).
 
 mk_conj_constraint_list(List) ->
   mk_constraint_list(conj, List).
-- 
cgit v1.2.3