From 1ad2431ec156658184aee68c1a5d9826ba06f506 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Valim?= <jose.valim@plataformatec.com.br>
Date: Thu, 28 Feb 2019 05:58:59 -0800
Subject: Optimize v3_kernel for thousands of clauses
Prior to this patch, v3_kernel would do multiple
passes on the clauses to group them. This commit
unrolls those passes, making v3_kernel up to 10%
faster in those cases.
---
lib/compiler/src/v3_kernel.erl | 78 +++++++++++++++++++++++++-----------------
1 file changed, 46 insertions(+), 32 deletions(-)
(limited to 'lib')
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 86351bc0c5..908d34e1b4 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -1590,19 +1590,12 @@ match_var([U|Us], Cs0, Def, St) ->
%% constructor/constant as first argument. Group the constructors
%% according to type, the order is really irrelevant but tries to be
%% smart.
-
-match_con(Us, Cs0, Def, St) ->
- %% Expand literals at the top level.
- Cs = [expand_pat_lit_clause(C) || C <- Cs0],
- match_con_1(Us, Cs, Def, St).
-
-match_con_1([U|_Us] = L, Cs, Def, St0) ->
+match_con([U|_Us] = L, Cs, Def, St0) ->
%% Extract clauses for different constructors (types).
%%ok = io:format("match_con ~p~n", [Cs]),
- Ttcs0 = select_types([k_binary], Cs) ++ select_bin_con(Cs) ++
- select_types([k_cons,k_tuple,k_map,k_atom,k_float,
- k_int,k_nil], Cs),
- Ttcs = opt_single_valued(Ttcs0),
+ Ttcs0 = select_types(Cs, [], [], [], [], [], [], [], [], []),
+ Ttcs1 = [{T, Types} || {T, [_ | _] = Types} <- Ttcs0],
+ Ttcs = opt_single_valued(Ttcs1),
%%ok = io:format("ttcs = ~p~n", [Ttcs]),
{Scs,St1} =
mapfoldl(fun ({T,Tcs}, St) ->
@@ -1613,8 +1606,41 @@ match_con_1([U|_Us] = L, Cs, Def, St0) ->
St0, Ttcs),
{build_alt_1st_no_fail(build_select(U, Scs), Def),St1}.
-select_types(Types, Cs) ->
- [{T,Tcs} || T <- Types, begin Tcs = select(T, Cs), Tcs =/= [] end].
+select_types([NoExpC | Cs], Bin, BinCon, Cons, Tuple, Map, Atom, Float, Int, Nil) ->
+ C = expand_pat_lit_clause(NoExpC),
+ case clause_con(C) of
+ k_binary ->
+ select_types(Cs, [C |Bin], BinCon, Cons, Tuple, Map, Atom, Float, Int, Nil);
+ k_bin_seg ->
+ select_types(Cs, Bin, [C | BinCon], Cons, Tuple, Map, Atom, Float, Int, Nil);
+ k_bin_end ->
+ select_types(Cs, Bin, [C | BinCon], Cons, Tuple, Map, Atom, Float, Int, Nil);
+ k_cons ->
+ select_types(Cs, Bin, BinCon, [C | Cons], Tuple, Map, Atom, Float, Int, Nil);
+ k_tuple ->
+ select_types(Cs, Bin, BinCon, Cons, [C | Tuple], Map, Atom, Float, Int, Nil);
+ k_map ->
+ select_types(Cs, Bin, BinCon, Cons, Tuple, [C | Map], Atom, Float, Int, Nil);
+ k_atom ->
+ select_types(Cs, Bin, BinCon, Cons, Tuple, Map, [C | Atom], Float, Int, Nil);
+ k_float ->
+ select_types(Cs, Bin, BinCon, Cons, Tuple, Map, Atom, [C | Float], Int, Nil);
+ k_int ->
+ select_types(Cs, Bin, BinCon, Cons, Tuple, Map, Atom, Float, [C | Int], Nil);
+ k_nil ->
+ select_types(Cs, Bin, BinCon, Cons, Tuple, Map, Atom, Float, Int, [C | Nil])
+ end;
+select_types([], Bin, BinCon, Cons, Tuple, Map, Atom, Float, Int, Nil) ->
+ [{k_binary, reverse(Bin)}] ++ handle_bin_con(reverse(BinCon)) ++
+ [
+ {k_cons, reverse(Cons)},
+ {k_tuple, reverse(Tuple)},
+ {k_map, reverse(Map)},
+ {k_atom, reverse(Atom)},
+ {k_float, reverse(Float)},
+ {k_int, reverse(Int)},
+ {k_nil, reverse(Nil)}
+ ].
expand_pat_lit_clause(#iclause{pats=[#ialias{pat=#k_literal{anno=A,val=Val}}=Alias|Ps]}=C) ->
P = expand_pat_lit(Val, A),
@@ -1743,20 +1769,12 @@ combine_bin_segs(#k_bin_end{}) ->
combine_bin_segs(_) ->
throw(not_possible).
-%% select_bin_con([Clause]) -> [{Type,[Clause]}].
-%% Extract clauses for the k_bin_seg constructor. As k_bin_seg
+%% handle_bin_con([Clause]) -> [{Type,[Clause]}].
+%% Handle clauses for the k_bin_seg constructor. As k_bin_seg
%% matching can overlap, the k_bin_seg constructors cannot be
%% reordered, only grouped.
-select_bin_con(Cs0) ->
- Cs1 = lists:filter(fun (C) ->
- Con = clause_con(C),
- (Con =:= k_bin_seg) or (Con =:= k_bin_end)
- end, Cs0),
- select_bin_con_1(Cs1).
-
-
-select_bin_con_1(Cs) ->
+handle_bin_con(Cs) ->
try
%% The usual way to match literals is to first extract the
%% value to a register, and then compare the register to the
@@ -1795,14 +1813,14 @@ select_bin_con_1(Cs) ->
end
catch
throw:not_possible ->
- select_bin_con_2(Cs)
+ handle_bin_con_not_possible(Cs)
end.
-select_bin_con_2([C1|Cs]) ->
+handle_bin_con_not_possible([C1|Cs]) ->
Con = clause_con(C1),
{More,Rest} = splitwith(fun (C) -> clause_con(C) =:= Con end, Cs),
- [{Con,[C1|More]}|select_bin_con_2(Rest)];
-select_bin_con_2([]) -> [].
+ [{Con,[C1|More]}|handle_bin_con_not_possible(Rest)];
+handle_bin_con_not_possible([]) -> [].
%% select_bin_int([Clause]) -> {k_bin_int,[Clause]}
%% If the first pattern in each clause selects the same integer,
@@ -1902,10 +1920,6 @@ select_utf8(Val0) ->
throw(not_possible)
end.
-%% select(Con, [Clause]) -> [Clause].
-
-select(T, Cs) -> [ C || C <- Cs, clause_con(C) =:= T ].
-
%% match_value([Var], Con, [Clause], Default, State) -> {SelectExpr,State}.
%% At this point all the clauses have the same constructor, we must
%% now separate them according to value.
--
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