%% -*- erlang-indent-level: 2 -*-
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%%=============================================================================
-module(hipe_ig_moves).
-export([new/1,
new_move/3,
get_moves/1]).
%%-----------------------------------------------------------------------------
%% The main data structure; its fields are:
%% - movelist : mapping from temp to set of associated move numbers
%% - nrmoves : number of distinct move instructions seen so far
%% - moveinsns : list of move instructions, in descending move number order
%% - moveset : set of move instructions
-record(ig_moves, {movelist :: movelist(),
nrmoves = 0 :: non_neg_integer(),
moveinsns = [] :: [{_,_}],
moveset = gb_sets:empty() :: gb_sets:set()}).
-type movelist() :: hipe_vectors:vector(ordsets:ordset(non_neg_integer())).
%%-----------------------------------------------------------------------------
-spec new(non_neg_integer()) -> #ig_moves{}.
new(NrTemps) ->
MoveList = hipe_vectors:new(NrTemps, ordsets:new()),
#ig_moves{movelist = MoveList}.
-spec new_move(_, _, #ig_moves{}) -> #ig_moves{}.
new_move(Dst, Src, IG_moves) ->
MoveSet = IG_moves#ig_moves.moveset,
MoveInsn = {Dst, Src},
case gb_sets:is_member(MoveInsn, MoveSet) of
true ->
IG_moves;
false ->
MoveNr = IG_moves#ig_moves.nrmoves,
Movelist0 = IG_moves#ig_moves.movelist,
Movelist1 = add_movelist(MoveNr, Dst,
add_movelist(MoveNr, Src, Movelist0)),
IG_moves#ig_moves{nrmoves = MoveNr+1,
movelist = Movelist1,
moveinsns = [MoveInsn|IG_moves#ig_moves.moveinsns],
moveset = gb_sets:insert(MoveInsn, MoveSet)}
end.
-spec add_movelist(non_neg_integer(), non_neg_integer(), movelist())
-> movelist().
add_movelist(MoveNr, Temp, MoveList) ->
AssocMoves = hipe_vectors:get(MoveList, Temp),
%% XXX: MoveNr does not occur in moveList[Temp], but the new list must be an
%% ordset due to the ordsets:union in hipe_coalescing_regalloc:combine().
hipe_vectors:set(MoveList, Temp, ordsets:add_element(MoveNr, AssocMoves)).
-spec get_moves(#ig_moves{}) -> {movelist(), non_neg_integer(), tuple()}.
get_moves(IG_moves) -> % -> {MoveList, NrMoves, MoveInsns}
{IG_moves#ig_moves.movelist,
IG_moves#ig_moves.nrmoves,
list_to_tuple(lists:reverse(IG_moves#ig_moves.moveinsns))}.
