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Diffstat (limited to 'lib/hipe/regalloc/hipe_regalloc_prepass.erl')
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diff --git a/lib/hipe/regalloc/hipe_regalloc_prepass.erl b/lib/hipe/regalloc/hipe_regalloc_prepass.erl new file mode 100644 index 0000000000..5024840237 --- /dev/null +++ b/lib/hipe/regalloc/hipe_regalloc_prepass.erl @@ -0,0 +1,953 @@ +%% -*- 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} = hipe_dsets:find({entry,L}, DSets0), + {ExitRoot, DSets} = hipe_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} = hipe_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 = hipe_dsets:union(R1, R2, DSets0), + {R, DSets} = hipe_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} = hipe_dsets:find({entry,L}, DSets0), + {ExitRoot, DSets2} = hipe_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() :: hipe_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 = hipe_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) -> hipe_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) -> + hipe_dsets:union({entry,L}, {exit,L}, DS); + ({_, {split, _, _}}, DS) -> DS + end, DSets0, PartBBList). + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% 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. |