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+%% -*- 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.
+%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%@doc
+%% PREPASS FOR ITERATED REGISTER ALLOCATORS
+%%
+%% Implements a trivial partial but optimal fast register allocator to be used
+%% as the first pass of the register allocation loop.
+%%
+%% The idea is to drastically reduce the number of temporaries, so as to speed
+%% up the real register allocators.
+%%
+%% * Spills trivially unallocatable temps
+%% This relies on the fact that calls intentionally clobber all registers.
+%% Since this is the case, any temp that is alive over a call can't possibly
+%% be allocated to anything but a spill slot.
+%%
+%% * Partitions the program at points where no pseudos that were not spiled are
+%% live, and then do register allocation on these partitions independently.
+%% These program points are commonly, but not exclusively, the call
+%% instructions.
+%%
+%% TODO
+%% * This module seems very successful at finding every single spill; register
+%% allocation performance should be improved if we short-circuit the first
+%% hipe_regalloc_loop iteration, skipping directly to rewrite without ever
+%% calling RegAllocMod.
+-module(hipe_regalloc_prepass).
+-export([regalloc/8, regalloc_initial/8]).
+
+-ifndef(DEBUG).
+-compile(inline).
+-endif.
+
+%%-define(DO_ASSERT, 1).
+-include("../main/hipe.hrl").
+
+%%% TUNABLES
+
+%% Partitions with fewer than ?TUNE_TOO_FEW_BBS basic block halves are merged
+%% together before register allocation.
+-define(TUNE_TOO_FEW_BBS, 256).
+
+%% Ignore the ra_partitioned option (and do whole function RA instead) when
+%% there are fewer than ?TUNE_MIN_SPLIT_BBS basic blocks.
+-define(TUNE_MIN_SPLIT_BBS, 384).
+
+%% We present a "pseudo-target" to the register allocator we wrap.
+-export([analyze/2,
+ all_precoloured/1,
+ allocatable/1,
+ args/2,
+ bb/3,
+ def_use/2,
+ defines/2,
+ is_fixed/2, % used by hipe_graph_coloring_regalloc
+ is_global/2,
+ is_move/2,
+ is_precoloured/2,
+ labels/2,
+ livein/3,
+ liveout/3,
+ non_alloc/2,
+ number_of_temporaries/2,
+ physical_name/2,
+ postorder/2,
+ reg_nr/2,
+ uses/2,
+ var_range/2,
+ reverse_postorder/2]).
+
+-record(prepass_ctx,
+ {target_mod :: module()
+ ,target_ctx :: target_context()
+ ,sub :: sub_map() % Translates temp numbers found in CFG and understood by
+ % Target to temp numbers passed to RegAllocMod.
+ ,inv :: inv_map() % Translates temp numbers passed to RegAllocMod
+ % to temp numbers found in CFG and understood by
+ % Target
+ ,max_phys :: temp() % Exclusive upper bound on physical registers
+ }).
+
+-record(cfg,
+ {cfg :: target_cfg()
+ ,bbs :: transformed_bbs()
+ ,max_reg :: temp() % Exclusive upper bound on temp numbers
+ ,rpostorder :: undefined % Only precomputed with partitioned cfg
+ | [label()]
+ }).
+
+-type bb() :: hipe_bb:bb(). % containing instr()
+-type liveset() :: ordsets:ordset(temp()).
+-record(transformed_bb,
+ {bb :: bb()
+ ,livein :: liveset()
+ ,liveout :: liveset()
+ }).
+-type transformed_bb() :: #transformed_bb{}.
+-type transformed_bbs() :: #{label() => transformed_bb()}.
+
+-record(instr,
+ {defuse :: {[temp()], [temp()]}
+ ,is_move :: boolean()
+ }).
+-type instr() :: #instr{}.
+
+-type target_cfg() :: any().
+-type target_instr() :: any().
+-type target_temp() :: any().
+-type target_reg() :: non_neg_integer().
+-type target_liveness() :: any().
+-type target_liveset() :: ordsets:ordset(target_reg()).
+-type target_context() :: any().
+-type spillno() :: non_neg_integer().
+-type temp() :: non_neg_integer().
+-type label() :: non_neg_integer().
+
+-spec regalloc(module(), target_cfg(), target_liveness(), spillno(), spillno(),
+ module(), target_context(), proplists:proplist())
+ -> {hipe_map(), spillno()}.
+regalloc(RegAllocMod, CFG, Liveness, SpillIndex0, SpillLimit, TargetMod,
+ TargetCtx, Options) ->
+ {Coloring, SpillIndex, same} =
+ regalloc_1(RegAllocMod, CFG, SpillIndex0, SpillLimit, TargetMod,
+ TargetCtx, Options, Liveness),
+ {Coloring, SpillIndex}.
+
+%% regalloc_initial/7 is allowed to introduce new temporaries, unlike
+%% regalloc/7.
+%% In order for regalloc/7 to never introduce temporaries, regalloc/7 must never
+%% choose to do split allocation unless regalloc_initial/7 does. This is the
+%% reason that the splitting heuristic is solely based on the number of basic
+%% blocks, which does not change during the register allocation loop.
+-spec regalloc_initial(module(), target_cfg(), target_liveness(), spillno(),
+ spillno(), module(), target_context(),
+ proplists:proplist())
+ -> {hipe_map(), spillno(), target_cfg(),
+ target_liveness()}.
+regalloc_initial(RegAllocMod, CFG0, Liveness0, SpillIndex0, SpillLimit,
+ TargetMod, TargetCtx, Options) ->
+ {Coloring, SpillIndex, NewCFG} =
+ regalloc_1(RegAllocMod, CFG0, SpillIndex0, SpillLimit, TargetMod, TargetCtx,
+ Options, Liveness0),
+ {CFG, Liveness} =
+ case NewCFG of
+ same -> {CFG0, Liveness0};
+ {rewritten, CFG1} -> {CFG1, TargetMod:analyze(CFG1, TargetCtx)}
+ end,
+ {Coloring, SpillIndex, CFG, Liveness}.
+
+regalloc_1(RegAllocMod, CFG0, SpillIndex0, SpillLimit, TargetMod, TargetCtx,
+ Options, Liveness) ->
+ {ScanBBs, Seen, SpillMap, SpillIndex1} =
+ scan_cfg(CFG0, Liveness, SpillIndex0, TargetMod, TargetCtx),
+
+ {PartColoring, SpillIndex, NewCFG} =
+ case proplists:get_bool(ra_partitioned, Options)
+ andalso length(TargetMod:labels(CFG0, TargetCtx)) > ?TUNE_MIN_SPLIT_BBS
+ of
+ true ->
+ regalloc_partitioned(SpillMap, SpillIndex1, SpillLimit, ScanBBs,
+ CFG0, TargetMod, TargetCtx, RegAllocMod, Options);
+ _ ->
+ regalloc_whole(Seen, SpillMap, SpillIndex1, SpillLimit, ScanBBs,
+ CFG0, TargetMod, TargetCtx, RegAllocMod, Options)
+ end,
+
+ SpillColors = [{T, {spill, S}} || {T, S} <- maps:to_list(SpillMap)],
+ Coloring = SpillColors ++ PartColoring,
+
+ ?ASSERT(begin
+ AllPrecoloured = TargetMod:all_precoloured(TargetCtx),
+ MaxPhys = lists:max(AllPrecoloured) + 1,
+ Unused = unused(live_pseudos(Seen, SpillMap, MaxPhys),
+ SpillMap, CFG0, TargetMod, TargetCtx),
+ unused_unused(Unused, CFG0, TargetMod, TargetCtx)
+ end),
+ ?ASSERT(begin
+ CFG =
+ case NewCFG of
+ same -> CFG0;
+ {rewritten, CFG1} -> CFG1
+ end,
+ check_coloring(Coloring, CFG, TargetMod, TargetCtx)
+ end), % Sanity-check
+ ?ASSERT(just_as_good_as(RegAllocMod, CFG, Liveness, SpillIndex0, SpillLimit,
+ TargetMod, TargetCtx, Options, SpillMap, Coloring,
+ Unused)),
+ {Coloring, SpillIndex, NewCFG}.
+
+regalloc_whole(Seen, SpillMap, SpillIndex0, SpillLimit, ScanBBs,
+ CFG, TargetMod, TargetCtx, RegAllocMod, Options) ->
+ AllPrecoloured = TargetMod:all_precoloured(TargetCtx),
+ MaxPhys = lists:max(AllPrecoloured) + 1,
+ LivePseudos = live_pseudos(Seen, SpillMap, MaxPhys),
+ {SubMap, InvMap, MaxPhys, MaxR, SubSpillLimit} =
+ number_and_map(AllPrecoloured, LivePseudos, SpillLimit),
+ BBs = transform_whole_cfg(ScanBBs, SubMap),
+ SubMod = #cfg{cfg=CFG, bbs=BBs, max_reg=MaxR},
+ SubContext = #prepass_ctx{target_mod=TargetMod, target_ctx=TargetCtx,
+ max_phys=MaxPhys, inv=InvMap, sub=SubMap},
+ {SubColoring, SpillIndex} =
+ RegAllocMod:regalloc(SubMod, SubMod, SpillIndex0, SubSpillLimit, ?MODULE,
+ SubContext, Options),
+ ?ASSERT(check_coloring(SubColoring, SubMod, ?MODULE, SubContext)),
+ {translate_coloring(SubColoring, InvMap), SpillIndex, same}.
+
+regalloc_partitioned(SpillMap, SpillIndex0, SpillLimit, ScanBBs,
+ CFG, TargetMod, TargetCtx, RegAllocMod, Options) ->
+ AllPrecoloured = TargetMod:all_precoloured(TargetCtx),
+ MaxPhys = lists:max(AllPrecoloured) + 1,
+
+ DSets0 = initial_dsets(CFG, TargetMod, TargetCtx),
+ PartBBList = part_cfg(ScanBBs, SpillMap, MaxPhys),
+ DSets1 = join_whole_blocks(PartBBList, DSets0),
+ {PartBBsRLList, DSets2} = merge_small_parts(DSets1),
+ {PartBBs, DSets3} = merge_pointless_splits(PartBBList, ScanBBs, DSets2),
+ SeenMap = collect_seenmap(PartBBsRLList, PartBBs),
+ {RPostMap, _DSets4} = part_order(TargetMod:reverse_postorder(CFG, TargetCtx),
+ DSets3),
+
+ {Allocations, SpillIndex} =
+ lists:mapfoldl(
+ fun({Root, Elems}, SpillIndex1) ->
+ #{Root := Seen} = SeenMap,
+ #{Root := RPost} = RPostMap,
+ LivePseudos = live_pseudos(Seen, SpillMap, MaxPhys),
+ {SubMap, InvMap, MaxPhys, MaxR, SubSpillLimit} =
+ number_and_map(AllPrecoloured, LivePseudos, SpillLimit),
+ BBs = transform_cfg(Elems, PartBBs, SubMap),
+ SubMod = #cfg{cfg=CFG, bbs=BBs, max_reg=MaxR, rpostorder=RPost},
+ SubContext = #prepass_ctx{target_mod=TargetMod, target_ctx=TargetCtx,
+ max_phys=MaxPhys, inv=InvMap, sub=SubMap},
+ {SubColoring, SpillIndex2} =
+ RegAllocMod:regalloc(SubMod, SubMod, SpillIndex1, SubSpillLimit,
+ ?MODULE, SubContext, Options),
+ ?ASSERT(check_coloring(SubColoring, SubMod, ?MODULE, SubContext)),
+ {{translate_coloring(SubColoring, InvMap), Elems}, SpillIndex2}
+ end, SpillIndex0, PartBBsRLList),
+ {Coloring, NewCFG} =
+ combine_allocations(Allocations, MaxPhys, PartBBs, TargetMod, TargetCtx,
+ CFG),
+ {Coloring, SpillIndex, NewCFG}.
+
+-spec number_and_map([target_reg()], target_liveset(), target_reg())
+ -> {sub_map(), inv_map(), temp(), temp(), temp()}.
+number_and_map(Phys, Pseud, SpillLimit) ->
+ MaxPhys = lists:max(Phys) + 1,
+ ?ASSERT(Pseud =:= [] orelse lists:min(Pseud) >= MaxPhys),
+ NrPseuds = length(Pseud),
+ MaxR = MaxPhys+NrPseuds,
+ PseudNrs = lists:zip(Pseud, lists:seq(MaxPhys, MaxR-1)),
+ MapList = lists:zip(Phys, Phys) % Physicals are identity-mapped
+ ++ PseudNrs,
+ ?ASSERT(MapList =:= lists:ukeysort(1, MapList)),
+ SubMap = {s,maps:from_list(MapList)},
+ InvMap = {i,maps:from_list([{Fake, Real} || {Real, Fake} <- MapList])},
+ SubSpillLimit = translate_spill_limit(MapList, SpillLimit),
+ {SubMap, InvMap, MaxPhys, MaxR, SubSpillLimit}.
+
+-spec translate_spill_limit([{target_reg(), temp()}], target_reg()) -> temp().
+translate_spill_limit([{Real,Fake}], SpillLimit) when Real < SpillLimit ->
+ Fake + 1;
+translate_spill_limit([{Real,_}|Ps], SpillLimit) when Real < SpillLimit ->
+ translate_spill_limit(Ps, SpillLimit);
+translate_spill_limit([{Real,Fake}|_], SpillLimit) when Real >= SpillLimit ->
+ Fake.
+
+-spec live_pseudos(seen(), spill_map(), target_reg()) -> target_liveset().
+live_pseudos(Seen, SpillMap, MaxPhys) ->
+ %% When SpillMap is much larger than Seen (which is typical in the partitioned
+ %% case), it is much more efficient doing it like this than making an ordset
+ %% of the spills and subtracting.
+ ordsets:from_list(
+ lists:filter(fun(R) -> R >= MaxPhys andalso not maps:is_key(R, SpillMap)
+ end, maps:keys(Seen))).
+
+-spec translate_coloring(hipe_map(), inv_map()) -> hipe_map().
+translate_coloring(SubColoring, InvMap) ->
+ lists:map(fun({T, P}) -> {imap_get(T, InvMap), P} end, SubColoring).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% First pass
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Spill trivially unallocatable temps, create internal target-independent
+%% program representation, and collect a set of all used temps.
+-record(spill_state,
+ {map :: spill_map()
+ ,ix :: spillno()
+ }).
+-type spill_state() :: #spill_state{}.
+-type spill_map() :: #{target_reg() => spillno()}.
+
+-spec scan_cfg(target_cfg(), target_liveness(), spillno(), module(),
+ target_context())
+ -> {scan_bbs()
+ ,seen()
+ ,spill_map()
+ ,spillno()
+ }.
+scan_cfg(CFG, Liveness, SpillIndex0, TgtMod, TgtCtx) ->
+ State0 = #spill_state{map=#{}, ix=SpillIndex0},
+ {BBs, Seen, #spill_state{map=Spill, ix=SpillIndex}} =
+ scan_bbs(TgtMod:labels(CFG,TgtCtx), CFG, Liveness, #{}, State0, #{}, TgtMod,
+ TgtCtx),
+ {BBs, Seen, Spill, SpillIndex}.
+
+-type seen() :: #{target_reg() => []}. % set
+-type scan_bb() :: {[instr()], target_liveset(), target_liveset()}.
+-type scan_bbs() :: #{label() => scan_bb()}.
+
+-spec scan_bbs([label()], target_cfg(), target_liveness(), seen(),
+ spill_state(), scan_bbs(), module(), target_context())
+ -> {scan_bbs(), seen(), spill_state()}.
+scan_bbs([], _CFG, _Liveness, Seen, State, BBs, _TgtMod, _TgtCtx) ->
+ {BBs, Seen, State};
+scan_bbs([L|Ls], CFG, Liveness, Seen0, State0, BBs, TgtMod, TgtCtx) ->
+ Liveout = t_liveout(Liveness, L, TgtMod, TgtCtx),
+ {Code, Livein, Seen, State} =
+ scan_bb(lists:reverse(hipe_bb:code(TgtMod:bb(CFG, L, TgtCtx))), Liveout,
+ Seen0, State0, [], TgtMod, TgtCtx),
+ BB = {Code, Livein, Liveout},
+ scan_bbs(Ls, CFG, Liveness, Seen, State, BBs#{L=>BB}, TgtMod, TgtCtx).
+
+-spec scan_bb([target_instr()], target_liveset(), seen(), spill_state(),
+ [instr()], module(), target_context())
+ -> {[instr()]
+ ,target_liveset()
+ ,seen()
+ ,spill_state()
+ }.
+scan_bb([], Live, Seen, State, IAcc, _TgtMod, _TgtCtx) ->
+ {IAcc, Live, Seen, State};
+scan_bb([I|Is], Live0, Seen0, State0, IAcc0, TgtMod, TgtCtx) ->
+ {TDef, TUse} = TgtMod:def_use(I,TgtCtx),
+ ?ASSERT(TDef =:= TgtMod:defines(I,TgtCtx)),
+ ?ASSERT(TUse =:= TgtMod:uses(I,TgtCtx)),
+ Def = ordsets:from_list(reg_names(TDef, TgtMod, TgtCtx)),
+ Use = ordsets:from_list(reg_names(TUse, TgtMod, TgtCtx)),
+ Live = ordsets:union(Use, ToSpill = ordsets:subtract(Live0, Def)),
+ Seen = add_seen(Def, add_seen(Use, Seen0)),
+ NewI = #instr{defuse={Def, Use}, is_move=TgtMod:is_move(I,TgtCtx)},
+ IAcc = [NewI|IAcc0],
+ State =
+ case TgtMod:defines_all_alloc(I,TgtCtx) of
+ false -> State0;
+ true -> spill_all(ToSpill, TgtMod, TgtCtx, State0)
+ end,
+ %% We can drop "no-ops" here; where (if anywhere) is it worth it?
+ scan_bb(Is, Live, Seen, State, IAcc, TgtMod, TgtCtx).
+
+-spec t_liveout(target_liveness(), label(), module(), target_context()) ->
+ target_liveset().
+t_liveout(Liveness, L, TgtMod, TgtCtx) ->
+ %% FIXME: unnecessary sort; liveout is sorted, reg_names(...) should be sorted
+ %% or consist of a few sorted subsequences (per type)
+ ordsets:from_list(reg_names(TgtMod:liveout(Liveness, L, TgtCtx), TgtMod,
+ TgtCtx)).
+
+-spec reg_names([target_temp()], module(), target_context()) -> [target_reg()].
+reg_names(Regs, TgtMod, TgtCtx) ->
+ [TgtMod:reg_nr(X,TgtCtx) || X <- Regs].
+
+-spec add_seen([target_reg()], seen()) -> seen().
+add_seen([], Seen) -> Seen;
+add_seen([R|Rs], Seen) -> add_seen(Rs, Seen#{R=>[]}).
+
+-spec spill_all([target_reg()], module(), target_context(), spill_state()) ->
+ spill_state().
+spill_all([], _TgtMod, _TgtCtx, State) -> State;
+spill_all([R|Rs], TgtMod, TgtCtx, State=#spill_state{map=Map, ix=Ix}) ->
+ case TgtMod:is_precoloured(R,TgtCtx) or maps:is_key(R, Map) of
+ true -> spill_all(Rs, TgtMod, TgtCtx, State);
+ false -> spill_all(Rs, TgtMod, TgtCtx,
+ State#spill_state{map=Map#{R=>Ix}, ix=Ix+1})
+ end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Second pass (without split)
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Rewrite CFG to the new temp names.
+-spec transform_whole_cfg(scan_bbs(), sub_map()) -> transformed_bbs().
+transform_whole_cfg(BBs0, SubMap) ->
+ maps:map(fun(_, BB) -> transform_whole_bb(BB, SubMap) end, BBs0).
+
+-spec transform_whole_bb(scan_bb(), sub_map()) -> transformed_bb().
+transform_whole_bb({Code, Livein, Liveout}, SubMap) ->
+ #transformed_bb{
+ bb=hipe_bb:mk_bb([I#instr{defuse={smap_get_all_partial(Def, SubMap),
+ smap_get_all_partial(Use, SubMap)}}
+ || I = #instr{defuse={Def,Use}} <- Code])
+ %% Assume mapping preserves monotonicity
+ ,livein=smap_get_all_partial(Livein, SubMap)
+ ,liveout=smap_get_all_partial(Liveout, SubMap)
+ }.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Second pass (with split)
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Discover program partitioning
+%% Regretfully, this needs to be a separate pass, as having the global live set
+%% is crucial to get a useful partitioning.
+
+%% Single-block parts are merged if there are multiple in a single block, as it
+%% is judged to not be beneficial to make them too small.
+
+-type part_bb_part() :: {[instr()], target_liveset(), target_liveset()}.
+-type part_bb() :: {single, part_bb_part()}
+ | {split, part_bb_part(), part_bb_part()}.
+-type part_bb_list() :: [{label(), part_bb()}].
+-type part_bbs() :: #{label() => part_bb()}.
+-type part_bb_sofar() :: single
+ | {split, [instr()], target_liveset()}. % , target_liveset()
+
+-spec part_cfg(scan_bbs(), spill_map(), target_reg()) -> part_bb_list().
+part_cfg(ScanBBs, SpillMap, MaxPhys) ->
+ Liveset = mk_part_liveset(SpillMap, MaxPhys),
+ lists:map(fun(BB) -> part_bb(BB, Liveset) end, maps:to_list(ScanBBs)).
+
+-spec part_bb({label(), scan_bb()}, part_liveset()) -> {label(), part_bb()}.
+part_bb({L, BB0={Code0, Livein, Liveout}}, Liveset) ->
+ {Sofar, NewCode} = part_bb_1(lists:reverse(Code0), Liveset, Liveout, []),
+ BB = case Sofar of
+ single ->
+ ?ASSERT(Code0 =:= NewCode),
+ {single, BB0};
+ {split, ExitCode, ExitLivein = EntryLiveout} ->
+ {split, {NewCode, Livein, EntryLiveout},
+ {ExitCode, ExitLivein, Liveout}}
+ end,
+ {L, BB}.
+
+-spec part_bb_1([instr()], part_liveset(), target_liveset(), [instr()])
+ -> {part_bb_sofar(), [instr()]}.
+part_bb_1([], _Liveset, _Livein, IAcc) -> {single, IAcc};
+part_bb_1([I=#instr{defuse={Def,Use}}|Is], Liveset, Live0, IAcc0) ->
+ Live = ordsets:union(Use, ordsets:subtract(Live0, Def)),
+ IAcc = [I|IAcc0],
+ case part_none_live(Live, Liveset) of
+ false -> part_bb_1(Is, Liveset, Live, IAcc);
+ %% One split point will suffice
+ true -> {{split, IAcc, Live}, lists:reverse(Is)}
+ end.
+
+-spec part_none_live(target_liveset(), part_liveset()) -> boolean().
+part_none_live(Live, Liveset) ->
+ not lists:any(fun(R) -> part_liveset_is_live(R, Liveset) end, Live).
+
+-type part_liveset() :: {spill_map(), target_reg()}.
+
+-spec mk_part_liveset(spill_map(), target_reg()) -> part_liveset().
+mk_part_liveset(SpillMap, MaxPhys) -> {SpillMap, MaxPhys}.
+
+-spec part_liveset_is_live(target_reg(), part_liveset()) -> boolean().
+part_liveset_is_live(R, {SpillMap, MaxPhys}) when is_integer(R) ->
+ R >= MaxPhys andalso not maps:is_key(R, SpillMap).
+
+%% @doc Merges split blocks where entry and exit belong to the same DSet.
+%% Does not change DSets
+-spec merge_pointless_splits(part_bb_list(), scan_bbs(), bb_dsets())
+ -> {part_bbs(), bb_dsets()}.
+merge_pointless_splits(PartBBList0, ScanBBs, DSets0) ->
+ {PartBBList, DSets} =
+ merge_pointless_splits_1(PartBBList0, ScanBBs, DSets0, []),
+ {maps:from_list(PartBBList), DSets}.
+
+-spec merge_pointless_splits_1(
+ part_bb_list(), scan_bbs(), bb_dsets(), part_bb_list())
+ -> {part_bb_list(), bb_dsets()}.
+merge_pointless_splits_1([], _ScanBBs, DSets, Acc) -> {Acc, DSets};
+merge_pointless_splits_1([P={_,{single,_}}|Ps], ScanBBs, DSets, Acc) ->
+ merge_pointless_splits_1(Ps, ScanBBs, DSets, [P|Acc]);
+merge_pointless_splits_1([P0={L,{split,_,_}}|Ps], ScanBBs, DSets0, Acc) ->
+ {EntryRoot, DSets1} = dsets_find({entry,L}, DSets0),
+ {ExitRoot, DSets} = dsets_find({exit,L}, DSets1),
+ case EntryRoot =:= ExitRoot of
+ false -> merge_pointless_splits_1(Ps, ScanBBs, DSets, [P0|Acc]);
+ true ->
+ %% Reuse the code list from ScanBBs rather than concatenating the split
+ %% parts
+ #{L := BB} = ScanBBs,
+ ?ASSERT(begin
+ {L,{split,{_EntryCode,_,_},{_ExitCode,_,_}}}=P0, % [_|
+ {_Code,_,_}=BB,
+ _Code =:= (_EntryCode ++ _ExitCode)
+ end),
+ merge_pointless_splits_1(Ps, ScanBBs, DSets, [{L,{single, BB}}|Acc])
+ end.
+
+-spec merge_small_parts(bb_dsets()) -> {bb_dsets_rllist(), bb_dsets()}.
+merge_small_parts(DSets0) ->
+ {RLList, DSets1} = dsets_to_rllist(DSets0),
+ RLLList = [{R, length(Elems), Elems} || {R, Elems} <- RLList],
+ merge_small_parts_1(RLLList, DSets1, []).
+
+-spec merge_small_parts_1(
+ [{bb_dset_key(), non_neg_integer(), [bb_dset_key()]}],
+ bb_dsets(), bb_dsets_rllist()
+ ) -> {bb_dsets_rllist(), bb_dsets()}.
+merge_small_parts_1([], DSets, Acc) -> {Acc, DSets};
+merge_small_parts_1([{R, _, Es}], DSets, Acc) -> {[{R, Es}|Acc], DSets};
+merge_small_parts_1([{R, L, Es}|Ps], DSets, Acc) when L >= ?TUNE_TOO_FEW_BBS ->
+ merge_small_parts_1(Ps, DSets, [{R,Es}|Acc]);
+merge_small_parts_1([Fst,{R, L, Es}|Ps], DSets, Acc)
+ when L >= ?TUNE_TOO_FEW_BBS ->
+ merge_small_parts_1([Fst|Ps], DSets, [{R,Es}|Acc]);
+merge_small_parts_1([{R1,L1,Es1},{R2,L2,Es2}|Ps], DSets0, Acc) ->
+ ?ASSERT(L1 < ?TUNE_TOO_FEW_BBS andalso L2 < ?TUNE_TOO_FEW_BBS),
+ DSets1 = dsets_union(R1, R2, DSets0),
+ {R, DSets} = dsets_find(R1, DSets1),
+ merge_small_parts_1([{R,L2+L1,Es2++Es1}|Ps], DSets, Acc).
+
+%% @doc Partition an ordering over BBs into subsequences for the dsets that
+%% contain them.
+%% Does not change dsets.
+-spec part_order([label()], bb_dsets())
+ -> {#{bb_dset_key() => [label()]}, bb_dsets()}.
+part_order(Lbs, DSets) -> part_order(Lbs, DSets, #{}).
+
+part_order([], DSets, Acc) -> {Acc, DSets};
+part_order([L|Ls], DSets0, Acc0) ->
+ {EntryRoot, DSets1} = dsets_find({entry,L}, DSets0),
+ {ExitRoot, DSets2} = dsets_find({exit,L}, DSets1),
+ Acc1 = map_append(EntryRoot, L, Acc0),
+ %% Only include the label once if both entry and exit is in same partition
+ Acc2 = case EntryRoot =:= ExitRoot of
+ true -> Acc1;
+ false -> map_append(ExitRoot, L, Acc1)
+ end,
+ part_order(Ls, DSets2, Acc2).
+
+map_append(Key, Elem, Map) ->
+ case Map of
+ #{Key := List} -> Map#{Key := [Elem|List]};
+ #{} -> Map#{Key => [Elem]}
+ end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Interference graph partitioning
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% We partition the program
+
+%% The algorithm considers two kinds of components; those that are local to a
+%% basic block, and those that are not. The key is that any basic block belongs
+%% to at most two non-local components; one from the beginning to the first
+%% split point, and one from the end to the last split point.
+
+-type bb_dset_key() :: {entry | exit, label()}.
+-type bb_dsets() :: dsets(bb_dset_key()).
+-type bb_dsets_rllist() :: [{bb_dset_key(), [bb_dset_key()]}].
+
+-spec initial_dsets(target_cfg(), module(), target_context()) -> bb_dsets().
+initial_dsets(CFG, TgtMod, TgtCtx) ->
+ Labels = TgtMod:labels(CFG, TgtCtx),
+ DSets0 = dsets_new(lists:append([[{entry,L},{exit,L}] || L <- Labels])),
+ Edges = lists:append([[{L, S} || S <- hipe_gen_cfg:succ(CFG, L)]
+ || L <- Labels]),
+ lists:foldl(fun({X, Y}, DS) -> dsets_union({exit,X}, {entry,Y}, DS) end,
+ DSets0, Edges).
+
+-spec join_whole_blocks(part_bb_list(), bb_dsets()) -> bb_dsets().
+join_whole_blocks(PartBBList, DSets0) ->
+ lists:foldl(fun({L, {single, _}}, DS) -> dsets_union({entry,L}, {exit,L}, DS);
+ ({_, {split, _, _}}, DS) -> DS
+ end, DSets0, PartBBList).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% The disjoint set forests data structure, for elements of arbitrary types.
+%% Note that the find operation mutates the set.
+%%
+%% We could do this more efficiently if we restricted the elements to integers,
+%% and used the (mutable) hipe arrays. For arbitrary terms ETS could be used,
+%% for a persistent interface (which isn't that nice when even accessors return
+%% modified copies), the array module could be used.
+-type dsets(X) :: #{X => {node, X} | {root, non_neg_integer()}}.
+
+-spec dsets_new([E]) -> dsets(E).
+dsets_new(Elems) -> maps:from_list([{E,{root,0}} || E <- Elems]).
+
+-spec dsets_find(E, dsets(E)) -> {E, dsets(E)}.
+dsets_find(E, DS0) ->
+ case DS0 of
+ #{E := {root,_}} -> {E, DS0};
+ #{E := {node,N}} ->
+ case dsets_find(N, DS0) of
+ {N, _}=T -> T;
+ {R, DS1} -> {R, DS1#{E := {node,R}}}
+ end
+ ;_ -> error(badarg, [E, DS0])
+ end.
+
+-spec dsets_union(E, E, dsets(E)) -> dsets(E).
+dsets_union(X, Y, DS0) ->
+ {XRoot, DS1} = dsets_find(X, DS0),
+ case dsets_find(Y, DS1) of
+ {XRoot, DS2} -> DS2;
+ {YRoot, DS2} ->
+ #{XRoot := {root,XRR}, YRoot := {root,YRR}} = DS2,
+ if XRR < YRR -> DS2#{XRoot := {node,YRoot}};
+ XRR > YRR -> DS2#{YRoot := {node,XRoot}};
+ true -> DS2#{YRoot := {node,XRoot}, XRoot := {root,XRR+1}}
+ end
+ end.
+
+-spec dsets_to_rllist(dsets(E)) -> {[{Root::E, Elems::[E]}], dsets(E)}.
+dsets_to_rllist(DS0) ->
+ {Lists, DS} = dsets_to_rllist(maps:keys(DS0), #{}, DS0),
+ {maps:to_list(Lists), DS}.
+
+dsets_to_rllist([], Acc, DS) -> {Acc, DS};
+dsets_to_rllist([E|Es], Acc, DS0) ->
+ {ERoot, DS} = dsets_find(E, DS0),
+ dsets_to_rllist(Es, map_append(ERoot, E, Acc), DS).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Third pass
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Collect all referenced temps in each partition.
+
+%% Note: The temps could be collected during the partition pass for each
+%% half-bb, and then combined here. Would that be beneficial?
+
+collect_seenmap(PartBBsRLList, PartBBs) ->
+ collect_seenmap(PartBBsRLList, #{}, PartBBs).
+
+collect_seenmap([], Acc, _PartBBs) -> Acc;
+collect_seenmap([{R,Elems}|Ps], Acc, PartBBs) ->
+ Seen = collect_seen_part(Elems, #{}, PartBBs),
+ collect_seenmap(Ps, Acc#{R => Seen}, PartBBs).
+
+collect_seen_part([], Acc, _PartBBs) -> Acc;
+collect_seen_part([{Half,L}|Es], Acc0, PartBBs) ->
+ BB = maps:get(L, PartBBs),
+ Code = case {Half, BB} of
+ {entry, {single, {C,_,_}}} -> C;
+ {entry, {split, {C,_,_}, _}} -> C;
+ {exit, {split, _, {C,_,_}}} -> C;
+ {exit, {single, _}} -> [] % Ignore; was collected by its entry half
+ end,
+ Acc = collect_seen_code(Code, Acc0),
+ collect_seen_part(Es, Acc, PartBBs).
+
+collect_seen_code([], Acc) -> Acc;
+collect_seen_code([#instr{defuse={Def,Use}}|Is], Acc) ->
+ collect_seen_code(Is, add_seen(Def, add_seen(Use, Acc))).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Fourth pass
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Rewrite CFG to the new temp names.
+-spec transform_cfg([bb_dset_key()], part_bbs(), sub_map()) -> transformed_bbs().
+
+transform_cfg(Elems, PartBBs, SubMap) ->
+ transform_cfg(Elems, PartBBs, SubMap, #{}).
+
+transform_cfg([], _PartBBs, _SubMap, Acc) -> Acc;
+transform_cfg([{Half,L}|Es], PartBBs, SubMap, Acc0) ->
+ #{L := PBB} = PartBBs,
+ Acc = case {Half, PBB} of
+ {entry, {single,BB}} -> Acc0#{L=>transform_bb(BB, SubMap)};
+ {entry, {split,BB,_}} -> Acc0#{L=>transform_bb(BB, SubMap)};
+ {exit, {split,_,BB}} -> Acc0#{L=>transform_bb(BB, SubMap)};
+ {exit, {single, _}} -> Acc0 % Was included by the entry half
+ end,
+ transform_cfg(Es, PartBBs, SubMap, Acc).
+
+-spec transform_bb(part_bb_part(), sub_map()) -> transformed_bb().
+transform_bb(BB, SubMap) ->
+ %% For now, part_bb_part() and split_bb() share representation
+ transform_whole_bb(BB, SubMap).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Fifth pass
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Combine colorings and substitute temps in actual cfg if there were
+%% collisions.
+
+%% A temp can sometimes appear in more than one partition. For example, defining
+%% an unused value. If these are found by combine_allocations, we have to
+%% rename this temp in one of the partitions on the real cfg.
+%%
+%% We optimistically assume that there will be no such collisions, and when
+%% there are, we fix them up as they're found.
+
+-spec combine_allocations([{hipe_map(), [bb_dset_key()]}], target_reg(),
+ part_bbs(), module(), target_context(), target_cfg())
+ -> {hipe_map(), same | {rewritten, target_cfg()}}.
+combine_allocations([{A,_}|As], MaxPhys, PartBBs, TgtMod, TgtCtx, CFG) ->
+ {Phys, Pseuds} = lists:partition(fun({R,_}) -> R < MaxPhys end, A),
+ {Seen, _, []} = partition_by_seen(Pseuds, #{}, [], []),
+ combine_allocations(As, MaxPhys, PartBBs, TgtMod, TgtCtx, Phys, Seen, Pseuds,
+ {same, CFG}).
+
+-spec combine_allocations([{hipe_map(), [bb_dset_key()]}], target_reg(),
+ part_bbs(), module(), target_context(), hipe_map(),
+ seen(), hipe_map(), {same|rewritten, target_cfg()})
+ -> {hipe_map(), same | {rewritten, target_cfg()}}.
+combine_allocations([], _MaxPhys, _PartBBs, _TgtMod, _TgtCtx, Phys, _Seen,
+ Pseuds, CFGT) ->
+ {Phys ++ Pseuds, case CFGT of
+ {same, _} -> same;
+ {rewritten, _} -> CFGT
+ end};
+combine_allocations([{A,PartElems}|As], MaxPhys, PartBBs, TgtMod, TgtCtx, Phys,
+ Seen0, Acc, CFGT={_,CFG0}) ->
+ {Phys, Pseuds0} = lists:partition(fun({R,_}) -> R < MaxPhys end, A),
+ {Seen, Pseuds, Collisions} = partition_by_seen(Pseuds0, Seen0, [], []),
+ case Collisions of
+ [] -> combine_allocations(As, MaxPhys, PartBBs, TgtMod, TgtCtx, Phys, Seen,
+ Pseuds++Acc, CFGT);
+ _ ->
+ %% There were collisions; rename all the temp numbers in Collisions
+ {CFG, Renamed} = rename(Collisions, PartElems, PartBBs, TgtMod, TgtCtx,
+ CFG0),
+ combine_allocations(As, MaxPhys, PartBBs, TgtMod, TgtCtx, Phys, Seen,
+ Pseuds++Renamed++Acc, {rewritten,CFG})
+ end.
+
+%% @doc Partitions a coloring on whether the registers are in the Seen set,
+%% adding any new registers to the set.
+-spec partition_by_seen(hipe_map(), seen(), hipe_map(), hipe_map())
+ -> {seen(), hipe_map(), hipe_map()}.
+partition_by_seen([], Seen, Acc, Collisions) -> {Seen, Acc, Collisions};
+partition_by_seen([C={R,_}|Cs], Seen, Acc, Colls) ->
+ case Seen of
+ #{R := _} -> partition_by_seen(Cs, Seen, Acc, [C|Colls]);
+ #{} -> partition_by_seen(Cs, Seen#{R => []}, [C|Acc], Colls)
+ end.
+
+-spec rename(hipe_map(), [bb_dset_key()], part_bbs(), module(),
+ target_context(), target_cfg())
+ -> {target_cfg(), hipe_map()}.
+rename(CollisionList, PartElems, PartBBs, TgtMod, TgtCtx, CFG0) ->
+ {Map, Renamed} = new_names(CollisionList, TgtMod, TgtCtx, #{}, []),
+ Fun = fun(I) ->
+ TgtMod:subst_temps(
+ fun(Temp) ->
+ N = TgtMod:reg_nr(Temp, TgtCtx),
+ case Map of
+ #{N := Subst} -> TgtMod:update_reg_nr(Subst, Temp, TgtCtx);
+ #{} -> Temp
+ end
+ end, I, TgtCtx)
+ end,
+ {rename_1(PartElems, PartBBs, TgtMod, TgtCtx, Fun, CFG0), Renamed}.
+
+-type rename_map() :: #{target_reg() => target_reg()}.
+-type rename_fun() :: fun((target_instr()) -> target_instr()).
+
+-spec new_names(hipe_map(), module(), target_context(), rename_map(),
+ hipe_map())
+ -> {rename_map(), hipe_map()}.
+new_names([], _TgtMod, _TgtCtx, Map, Renamed) -> {Map, Renamed};
+new_names([{R,C}|As], TgtMod, TgtCtx, Map, Renamed) ->
+ Subst = TgtMod:new_reg_nr(TgtCtx),
+ new_names(As, TgtMod, TgtCtx, Map#{R => Subst}, [{Subst, C} | Renamed]).
+
+%% @doc Maps over all instructions in a partition on the original CFG.
+-spec rename_1([bb_dset_key()], part_bbs(), module(), target_context(),
+ rename_fun(), target_cfg()) -> target_cfg().
+rename_1([], _PartBBs, _TgtMod, _TgtCtx, _Fun, CFG) -> CFG;
+rename_1([{Half,L}|Es], PartBBs, TgtMod, TgtCtx, Fun, CFG0) ->
+ Code0 = hipe_bb:code(BB = TgtMod:bb(CFG0, L, TgtCtx)),
+ Code = case {Half, maps:get(L, PartBBs)} of
+ {entry, {single,_}} -> lists:map(Fun, Code0);
+ {entry, {split,PBBP,_}} ->
+ map_start(Fun, part_bb_part_len(PBBP), Code0);
+ {exit, {split,_,PBBP}} ->
+ map_end(Fun, part_bb_part_len(PBBP), Code0);
+ {exit, {single, _}} -> Code0
+ end,
+ CFG = TgtMod:update_bb(CFG0, L, hipe_bb:code_update(BB, Code), TgtCtx),
+ rename_1(Es, PartBBs, TgtMod, TgtCtx, Fun, CFG).
+
+-spec part_bb_part_len(part_bb_part()) -> non_neg_integer().
+part_bb_part_len({Code, _Livein, _Liveout}) -> length(Code).
+
+%% @doc Map the first N elements of a list
+-spec map_start(fun((X) -> Y), non_neg_integer(), [X]) -> [X|Y].
+map_start(_Fun, 0, List) -> List;
+map_start(Fun, N, [E|Es]) ->
+ [Fun(E)|map_start(Fun, N-1, Es)].
+
+%% @doc Map the last N elements of a list
+-spec map_end(fun((X) -> Y), non_neg_integer(), [X]) -> [X|Y].
+map_end(Fun, N, List) ->
+ map_end(Fun, N, length(List), List).
+
+map_end(Fun, N, Len, [E|Es]) when Len > N -> [E|map_end(Fun, N, Len-1, Es)];
+map_end(Fun, N, Len, List) when Len =:= N -> lists:map(Fun, List).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Temp map ADT
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-type sub_map() :: {s,#{target_reg() => temp()}}.
+-type inv_map() :: {i,#{temp() => target_reg()}}.
+
+-spec smap_get(target_reg(), sub_map()) -> temp().
+smap_get(Temp, {s,Map}) when is_integer(Temp) -> maps:get(Temp, Map).
+
+-spec imap_get(temp(), inv_map()) -> target_reg().
+imap_get(Temp, {i,Map}) when is_integer(Temp) -> maps:get(Temp, Map).
+
+-spec smap_get_all_partial([target_reg()], sub_map()) -> [temp()].
+smap_get_all_partial([], _) -> [];
+smap_get_all_partial([T|Ts], SMap={s,Map}) when is_integer(T) ->
+ case Map of
+ #{T := R} -> [R|smap_get_all_partial(Ts, SMap)];
+ #{} -> smap_get_all_partial(Ts, SMap)
+ end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Validation
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-ifdef(DO_ASSERT).
+%%%%%%%%%%%%%%%%%%%%
+%% Check that the coloring is correct (if the IG is correct):
+%%
+
+%% Define these as 'ok' or 'report(X,Y)' depending on how much output you want.
+-define(report0(X,Y), ?IF_DEBUG_LEVEL(0,?msg(X, Y),ok)).
+-define(report(X,Y), ?IF_DEBUG_LEVEL(1,?msg(X, Y),ok)).
+-define(report2(X,Y), ?IF_DEBUG_LEVEL(2,?msg(X, Y),ok)).
+-define(report3(X,Y), ?IF_DEBUG_LEVEL(3,?msg(X, Y),ok)).
+
+check_coloring(Coloring, CFG, TgtMod, TgtCtx) ->
+ ?report0("checking coloring ~p~n",[Coloring]),
+ IG = hipe_ig:build(CFG, TgtMod:analyze(CFG,TgtCtx), TgtMod, TgtCtx),
+ check_cols(hipe_vectors:list(hipe_ig:adj_list(IG)),
+ init_coloring(Coloring, TgtMod, TgtCtx)).
+
+init_coloring(Xs, TgtMod, TgtCtx) ->
+ hipe_temp_map:cols2tuple(Xs, TgtMod, TgtCtx).
+
+check_color_of(X, Cols) ->
+ case hipe_temp_map:find(X, Cols) of
+ unknown ->
+ uncolored;
+ C ->
+ C
+ end.
+
+check_cols([], _Cols) ->
+ ?report("coloring valid~n",[]),
+ true;
+check_cols([{X,Neighbours}|Xs], Cols) ->
+ Cs = [{N, check_color_of(N, Cols)} || N <- Neighbours],
+ C = check_color_of(X, Cols),
+ case valid_coloring(X, C, Cs) of
+ yes ->
+ check_cols(Xs, Cols);
+ {no,Invalids} ->
+ ?msg("node ~p has same color (~p) as ~p~n", [X,C,Invalids]),
+ check_cols(Xs, Cols) andalso false
+ end.
+
+valid_coloring(_X, _C, []) ->
+ yes;
+valid_coloring(X, C, [{Y,C}|Ys]) ->
+ case valid_coloring(X, C, Ys) of
+ yes -> {no, [Y]};
+ {no,Zs} -> {no, [Y|Zs]}
+ end;
+valid_coloring(X, C, [_|Ys]) ->
+ valid_coloring(X, C, Ys).
+
+unused_unused(Unused, CFG, TgtMod, TgtCtx) ->
+ IG = hipe_ig:build(CFG, TgtMod:analyze(CFG,TgtCtx), TgtMod, TgtCtx),
+ lists:all(fun(R) -> case hipe_ig:get_node_degree(R, IG) of
+ 0 -> true;
+ Deg ->
+ ?msg("Temp ~w is in unused but has degree ~w~n",
+ [R, Deg]),
+ false
+ end end, Unused).
+
+%%%%%%%%%%%%%%%%%%%%
+%% Check that no register allocation opportunities were missed due to ?MODULE
+%%
+just_as_good_as(RegAllocMod, CFG, Liveness, SpillIndex0, SpillLimit, TgtMod,
+ TgtCtx, Options, SpillMap, Coloring, Unused) ->
+ {CheckColoring, _} =
+ RegAllocMod:regalloc(CFG, Liveness, SpillIndex0, SpillLimit, TgtMod, TgtCtx,
+ Options),
+ Now = lists:sort([{R,Kind} || {R,{Kind,_}} <- Coloring,
+ not ordsets:is_element(R, Unused)]),
+ Check = lists:sort([{R,Kind} || {R,{Kind,_}} <- CheckColoring,
+ not ordsets:is_element(R, Unused)]),
+ CheckMap = maps:from_list(Check),
+ SaneSpills = all_spills_sane_1(CheckColoring, SpillMap),
+ case SaneSpills
+ andalso lists:all(fun({R, spill}) -> maps:get(R, CheckMap) =:= spill;
+ ({_,reg}) -> true
+ end, Now)
+ of
+ true -> true;
+ false ->
+ {NowRegs, _} = _NowCount = count(Now),
+ {CheckRegs, _} = _CheckCount = count(Check),
+ {M,F,A} = element(2, element(3, CFG)),
+ io:fwrite(standard_error, "Colorings differ (~w, ~w)!~n"
+ "MFA: ~w:~w/~w~n"
+ "Unused: ~w~n"
+ "Now:~w~nCorrect:~w~n",
+ [TgtMod, RegAllocMod,
+ M,F,A,
+ Unused,
+ Now -- Check, Check -- Now]),
+ SaneSpills andalso NowRegs >= CheckRegs
+ end.
+
+count(C) -> {length([[] || {_, reg} <- C]),
+ length([[] || {_, spill} <- C])}.
+
+unused(LivePseudos, SpillMap, CFG, TgtMod, TgtCtx) ->
+ {TMin, TMax} = TgtMod:var_range(CFG,TgtCtx),
+ SpillOSet = ordsets:from_list(maps:keys(SpillMap)),
+ PhysOSet = ordsets:from_list(TgtMod:all_precoloured(TgtCtx)),
+ Used = ordsets:union(LivePseudos, ordsets:union(PhysOSet, SpillOSet)),
+ ordsets:subtract(lists:seq(TMin, TMax), Used).
+
+%% Check that no temp that we wrote off was actually allocatable.
+all_spills_sane_1(_, Empty) when map_size(Empty) =:= 0 -> true;
+all_spills_sane_1([], _Nonempty) -> false;
+all_spills_sane_1([{T, {reg, _}}|Cs], SpillMap) ->
+ not maps:is_key(T, SpillMap) andalso all_spills_sane_1(Cs, SpillMap);
+all_spills_sane_1([{T, {spill, _}}|Cs], SpillMap) ->
+ all_spills_sane_1(Cs, maps:remove(T, SpillMap)).
+
+-endif. % DO_ASSERT
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Pseudo-target interface
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+analyze(Cfg, _ModRec) -> Cfg.
+bb(Cfg=#cfg{bbs=BBs}, Ix, _ModRec) ->
+ case BBs of
+ #{Ix := #transformed_bb{bb=BB}} -> BB;
+ _ -> error(badarg, [Cfg, Ix])
+ end.
+args(Arity, #prepass_ctx{target_mod=TgtMod, target_ctx=TgtCtx, sub=SubM}) ->
+ smap_get(TgtMod:args(Arity,TgtCtx), SubM).
+labels(#cfg{bbs=BBs}, _ModRec) -> maps:keys(BBs).
+livein(#cfg{bbs=BBs}, Lb, _SubMod) ->
+ #{Lb := #transformed_bb{livein=Livein}} = BBs,
+ Livein.
+liveout(#cfg{bbs=BBs}, Lb, _SubMod) ->
+ #{Lb := #transformed_bb{liveout=Liveout}} = BBs,
+ Liveout.
+uses(I, MR) -> element(2, def_use(I, MR)).
+defines(I, MR) -> element(1, def_use(I, MR)).
+def_use(#instr{defuse=DefUse}, _ModRec) -> DefUse.
+is_move(#instr{is_move=IM}, _ModRec) -> IM.
+is_fixed(Reg, #prepass_ctx{target_mod=TgtMod,target_ctx=TgtCtx,inv=InvM}) ->
+ TgtMod:is_fixed(imap_get(Reg, InvM),TgtCtx). % XXX: Is this hot?
+is_global(Reg, #prepass_ctx{target_mod=TgtMod,target_ctx=TgtCtx,
+ max_phys=MaxPhys}) when Reg < MaxPhys ->
+ TgtMod:is_global(Reg,TgtCtx). % assume id-map
+is_precoloured(Reg, #prepass_ctx{max_phys=MaxPhys}) -> Reg < MaxPhys.
+reg_nr(Reg, _ModRec) -> Reg. % After mapping (naturally)
+non_alloc(#cfg{cfg=CFG}, #prepass_ctx{target_mod=TgtMod,target_ctx=TgtCtx,
+ sub=SubM}) ->
+ smap_get_all_partial(reg_names(TgtMod:non_alloc(CFG,TgtCtx), TgtMod, TgtCtx),
+ SubM).
+number_of_temporaries(#cfg{max_reg=MaxR}, _ModRec) -> MaxR.
+allocatable(#prepass_ctx{target_mod=TgtMod, target_ctx=TgtCtx}) ->
+ TgtMod:allocatable(TgtCtx). % assume id-map
+physical_name(Reg, _ModRec) -> Reg.
+all_precoloured(#prepass_ctx{target_mod=TgtMod, target_ctx=TgtCtx}) ->
+ TgtMod:all_precoloured(TgtCtx). % dito
+var_range(#cfg{cfg=_CFG, max_reg=MaxReg},
+ #prepass_ctx{target_mod=_TgtMod, target_ctx=_TgtCtx}) ->
+ ?ASSERT(begin {TgtMin, _} = _TgtMod:var_range(_CFG,_TgtCtx),
+ TgtMin =:= 0
+ end),
+ {0, MaxReg-1}.
+
+postorder(#cfg{cfg=CFG,rpostorder=undefined},
+ #prepass_ctx{target_mod=TgtMod,target_ctx=TgtCtx}) ->
+ TgtMod:postorder(CFG,TgtCtx);
+postorder(#cfg{rpostorder=Labels}, _ModRec) when is_list(Labels) ->
+ lists:reverse(Labels).
+
+reverse_postorder(#cfg{cfg=CFG,rpostorder=undefined},
+ #prepass_ctx{target_mod=TgtMod,target_ctx=TgtCtx}) ->
+ TgtMod:reverse_postorder(CFG,TgtCtx);
+reverse_postorder(#cfg{rpostorder=Labels}, _ModRec) when is_list(Labels) ->
+ Labels.