%% -*- erlang-indent-level: 2 -*- %% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2001-2016. 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. %% 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. %% %% %CopyrightEnd% %% %% ===================================================================== %% @doc %% 
%%  Module   :	hipe_ls_regalloc
%%  Purpose  :  Perform a register allocation based on the 
%%              "linear-scan algorithm".
%%  Notes    :  * This is an implementation of 
%%                "Linear Scan Register Allocation" by 
%%                Massimiliano Poletto & Vivek Sarkar described in
%%                ACM TOPLAS Vol 21, No 5, September 1999.
%%
%%              * This implementation is target-independent and
%%                requires a target specific interface module
%%                as argument.  
%%                (Still waiting for a modular module system for Erlang.)
%%
%% @end %% %% History : * 2000-04-07 Erik Johansson (happi@it.uu.se): Created. %% * 2001-07-16 Erik Johansson: Made less sparc-specific. %% ===================================================================== %% Exported functions (short description): %% regalloc(CFG,PhysRegs,Entrypoints, Options) -> %% {Coloring, NumberOfSpills} %% Takes a CFG and returns a coloring of all used registers. %% PhysRegs should be a list of available physical registers. %% Entrypoints should be a list of names of Basic Blocks that have %% external entry points. %% %% The Coloring will be in the form of the "allocation datastructure" %% described below, that is, a list of tuples on the form %% {Name, {reg, PhysicalRegister}} or %% {Name, {spill, SpillIndex}} %% The NumberOfSpills is either 0 indicating no spill or the %% SpillIndex of the last spilled register. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -module(hipe_ls_regalloc). -export([regalloc/7, regalloc/8]). %%-define(DEBUG,1). -define(HIPE_INSTRUMENT_COMPILER, true). -include("../main/hipe.hrl"). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% @spec %% regalloc(CFG, PhysRegs, Entrypoints, SpillIndex, DontSpill, Options, %% Target) -> %% {Coloring, NumberOfSpills} %% CFG = cfg() %% PhysRegs = [reg()] %% Entrypoints = [labelname()] %% DontSpill = reg() %% Options = proplists:proplist() %% Target = atom() %% Coloring = [{temp(), pos()}] %% NumberOfSpills = integer() %% reg() = integer() %% temp() = integer() %% pos() = {reg, reg()} | {spill, integer()} %% %% @doc %% Calculates an allocation of registers using a linear_scan algorithm. %% There are three steps in the algorithm: %%
    %%
  1. Calculate live-ranges for all registers.
    2. %%
  2. Calculate live-intervals for each register. %% The live interval consists of a start position and an end %% position. These are the first definition and last use of the %% register given as instruction numbers in a breadth-first %% traversal of the control-flow-graph.
    3. %%
  3. Perform a linear scan allocation over the live intervals.
    4. %%
%% @end %%- - - - - - - - - - - - - - - - - - - - - - - - regalloc(CFG, PhysRegs, Entrypoints, SpillIndex, DontSpill, Options, Target) -> regalloc(CFG, undefined, PhysRegs, Entrypoints, SpillIndex, DontSpill, Options, Target). regalloc(CFG, Liveness0, PhysRegs, Entrypoints, SpillIndex, DontSpill, Options, Target) -> ?debug_msg("LinearScan: ~w\n", [erlang:statistics(runtime)]), %% Step 1: Calculate liveness (Call external implementation.) Liveness = case Liveness0 of undefined -> L=liveness(CFG, Target), ?debug_msg("liveness (done)~w\n", [erlang:statistics(runtime)]), L; _ -> Liveness0 end, USIntervals = calculate_intervals(CFG, Liveness, Entrypoints, Options, Target), ?debug_msg("intervals (done) ~w\n", [erlang:statistics(runtime)]), Intervals = sort_on_start(USIntervals), ?debug_msg("sort intervals (done) ~w\n", [erlang:statistics(runtime)]), %% ?debug_msg("Intervals ~w\n", [Intervals]), ?debug_msg("No intervals: ~w\n",[length(Intervals)]), ?debug_msg("count intervals (done) ~w\n", [erlang:statistics(runtime)]), {Coloring, NewSpillIndex} = allocate(Intervals, PhysRegs, SpillIndex, DontSpill, Target), ?debug_msg("allocation (done) ~w\n", [erlang:statistics(runtime)]), {Coloring, NewSpillIndex, Liveness}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% %% Step 2: Calculate live-intervals for each register. %% %% %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%- - - - - - - - - - - - - - - - - - - - - - - - %% calculate_intervals(CFG,Liveness,Entrypoints, Options, Target) %% CFG: The Control-Flow Graph. %% Liveness: A map of live-in and live-out sets for each Basic-Block. %% Entrypoints: A set of BB names that have external entrypoints. %% calculate_intervals(CFG,Liveness,_Entrypoints, Options, Target) -> %% Add start point for the argument registers. Args = arg_vars(CFG, Target), Interval = add_def_point(Args, 0, empty_interval(Target:number_of_temporaries(CFG))), %% Interval = add_livepoint(Args, 0, empty_interval()), Worklist = case proplists:get_value(ls_order, Options) of reversepostorder -> Target:reverse_postorder(CFG); breadth -> Target:breadthorder(CFG); postorder -> Target:postorder(CFG); inorder -> Target:inorder(CFG); reverse_inorder -> Target:reverse_inorder(CFG); preorder -> Target:preorder(CFG); prediction -> Target:predictionorder(CFG); random -> Target:labels(CFG); _ -> Target:reverse_postorder(CFG) end, %% ?inc_counter(bbs_counter, length(Worklist)), %% ?debug_msg("No BBs ~w\n",[length(Worklist)]), intervals(Worklist, Interval, 1, CFG, Liveness, Target). %%- - - - - - - - - - - - - - - - - - - - - - - - %% intervals(WorkList, Intervals, InstructionNr, CFG, Liveness, Target) %% WorkList: List of BB-names to handle. %% Intervals: Intervals seen so far (sorted on register names). %% InstructionNr: The number of examined insturctions. %% CFG: The Control-Flow Graph. %% Liveness: A map of live-in and live-out sets for each Basic-Block. %% Target: The backend for which we generate code. %%- - - - - - - - - - - - - - - - - - - - - - - - intervals([L|ToDO], Intervals, InstructionNr, CFG, Liveness, Target) -> %% Add all variables that are live at the entry of this block %% to the interval data structure. LiveIn = livein(Liveness, L, Target), Intervals2 = add_def_point(LiveIn, InstructionNr, Intervals), LiveOut = liveout(Liveness, L, Target), %% Traverse this block instruction by instruction and add all %% uses and defines to the intervals. Code = hipe_bb:code(bb(CFG, L, Target)), {Intervals3, NewINr} = traverse_block(Code, InstructionNr+1, Intervals2, Target), %% Add end points for the registers that are in the live-out set. Intervals4 = add_use_point(LiveOut, NewINr+1, Intervals3), intervals(ToDO, Intervals4, NewINr+1, CFG, Liveness, Target); intervals([], Intervals, _, _, _, _) -> %% Return the calculated intervals LI = interval_to_list(Intervals), %% io:format("Intervals:~n~p~n", [LI]), LI. %%- - - - - - - - - - - - - - - - - - - - - - - - %% traverse_block(Code, InstructionNo, Intervals, Unchanged) %% Examine each instruction in the Code: %% For each temporary T used or defined by instruction number N: %% extend the interval of T to include N. %%- - - - - - - - - - - - - - - - - - - - - - - - traverse_block([Instruction|Is],InstrNo,Intervals, Target) -> %% Get defined temps. DefsSet = defines(Instruction, Target), Intervals1 = add_def_point(DefsSet, InstrNo, Intervals), %% Get used temps. UsesSet = uses(Instruction, Target), %% Extend the intervals for these temporaries to include InstrNo. Intervals2 = add_use_point(UsesSet, InstrNo, Intervals1), %% Handle the next instruction. traverse_block(Is,InstrNo+1,Intervals2,Target); traverse_block([], InstrNo, Intervals, _) -> %% Return the new intervals and the number of the next instruction. {Intervals,InstrNo}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% %% Step 3. Do a linear scan allocation over the live intervals. %% %% %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% allocate(Intervals, PhysicalRegisters, DontSpill, Target) %% %% This function performs the linear scan algorithm. %% Intervals contains the start and stop position of each register, %% sorted on increasing startpositions %% PhysicalRegisters is a list of available Physical registers to use. %% %%- - - - - - - - - - - - - - - - - - - - - - - - allocate(Intervals, PhysRegs, SpillIndex, DontSpill, Target) -> ActiveRegisters =[], AllocatedRegisters = empty_allocation(), AllFree = create_freeregs(PhysRegs), allocate(Intervals, AllFree, ActiveRegisters, AllocatedRegisters, SpillIndex, DontSpill, Target). %%- - - - - - - - - - - - - - - - - - - - - - - - %% allocate(Intervals, Free, Active, Allocated, SpillIndex, Target) %% Iterates of each register interval. %% Intervals: The list of register intervals. %% Free: Currently available physical registers. %% Active: Currently used physical registers (sorted on increasing %% interval enpoints) %% Allocated: The mapping of register names to physical registers or %% to spill positions. %% SpillIndex: The number of spilled registers. %%- - - - - - - - - - - - - - - - - - - - - - - - allocate([RegInt|RIS], Free, Active, Alloc, SpillIndex, DontSpill, Target) -> %io:format("~nAlloc:~n~p", [Alloc]), %% Remove from the active list those registers who's intervals %% ends before the start of the current interval. {NewActive, NewFree} = expire_old_intervals(Active, startpoint(RegInt), Free, Target), ?debug_msg("Alloc interval: ~w, Free ~w\n",[RegInt, NewFree]), %% Get the name of the temp in the current interval. Temp = reg(RegInt), case is_precoloured(Temp, Target) of true -> %% This is a precoloured register we don't need to find a color %% Get the physical name of the register. PhysName = physical_name(Temp, Target), %% Bind it to the precoloured name. NewAlloc = alloc(Temp, PhysName, Alloc), case is_global(Temp, Target) of true -> %% this is a global precoloured register allocate(RIS, NewFree, NewActive, NewAlloc, SpillIndex, DontSpill, Target); false -> case is_free(PhysName, NewFree) of {true,Rest} -> allocate(RIS, Rest, add_active(endpoint(RegInt), startpoint(RegInt), PhysName, Temp, NewActive), NewAlloc, SpillIndex, DontSpill, Target); false -> %% Some other temp has taken this precoloured register, %% throw it out. {OtherActive, NewActive2} = deactivate(PhysName, NewActive), OtherTemp = active_name(OtherActive), OtherEnd = active_endpoint(OtherActive), OtherStart = active_startpoint(OtherActive), NewActive3 = add_active(endpoint(RegInt), startpoint(RegInt), PhysName, Temp, NewActive2), case exists_free_register(OtherStart, NewFree) of {true, NewPhys, RestFree} -> allocate(RIS, RestFree, add_active(OtherEnd, OtherStart, NewPhys, OtherTemp, NewActive3), alloc(OtherTemp,NewPhys,NewAlloc), SpillIndex, DontSpill, Target); false -> NewSpillIndex = Target:new_spill_index(SpillIndex), {NewAlloc2, NewActive4} = spill(OtherTemp, OtherEnd, OtherStart, NewActive3, NewAlloc, SpillIndex, DontSpill, Target), allocate(RIS, NewFree, NewActive4, NewAlloc2, NewSpillIndex, DontSpill, Target) end end end; false -> %% This is not a precoloured register. case NewFree of [] -> %% No physical registers available, we have to spill. NewSpillIndex = Target:new_spill_index(SpillIndex), {NewAlloc, NewActive2} = spill(Temp, endpoint(RegInt), startpoint(RegInt), Active, Alloc, SpillIndex, DontSpill, Target), %% io:format("Spilled ~w\n",[NewAlloc]), allocate(RIS, NewFree, NewActive2, NewAlloc, NewSpillIndex, DontSpill, Target); [{FreeReg,_Start} | Regs] -> %% The register FreeReg is available, let's use it. %%io:format("Allocating Reg:~p~n",[FreeReg]), allocate(RIS,Regs, add_active(endpoint(RegInt), startpoint(RegInt), FreeReg, Temp, NewActive), alloc(Temp, FreeReg, Alloc), SpillIndex, DontSpill, Target) end end; allocate([],_,_,Alloc,SpillIndex, _, _) -> %% No more register intervals to handle %% return the result. %%io:format("~nAlloc:~n~p", [Alloc]), {Alloc, SpillIndex}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% expire_old_intervals(ActiveRegisters, CurrentPos, FreeRegisters) %% Remove all registers that have live-ranges that ends before the %% current position from the active list and put them into the free %% list instead. %% %% --------------------------------------------------------------------- expire_old_intervals([Act|Acts] = AllActives, CurrentPos, Free, Target) -> %% Does the live-range of the first active register end before %% the current position? %% We expand multimove before regalloc, ignore the next 2 lines. %% %% We don't free registers that end at the current position, %% %% since a multimove can decide to do the moves in another order... case active_endpoint(Act) =< CurrentPos of true -> %% Yes -> Then we can free that register. Reg = active_reg(Act), %% Add the register to the free pool. NewFree = case is_arg(Reg, Target) of true -> [{Reg, CurrentPos}|Free]; false -> [{Reg, CurrentPos}|Free] %% Here we could try appending the %% register to get a more widespread %% use of registers. %% Free ++ [active_reg(Act)]); %% At the moment this does not seem to %% improve performance at all, %% on the other hand, the cost is very low. end, expire_old_intervals(Acts, CurrentPos, NewFree, Target); false -> %% No -> Then we cannot free any more registers. %% (Since they are sorted on endpoints...) {AllActives, Free} end; expire_old_intervals([], _, Free, _) -> {[], Free}. deactivate(Reg, [Active|Actives]) -> case Reg =:= active_reg(Active) of true -> {Active, Actives}; false -> {TheActive, NewActives} = deactivate(Reg, Actives), {TheActive, [Active|NewActives]} end; deactivate(_,[]) -> {no,[]}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% spill(CurrentReg, CurrentEndpoint, Active, Alloc, SpillIndex, %% DontSpill, Target) %% Find the register with the longest live range and spill it to memory. %% %% --------------------------------------------------------------------- spill(CurrentReg, CurrentEndpoint,CurrentStartpoint, Active = [_|_], Alloc, SpillIndex, DontSpill, Target) -> ?debug_msg("spilling one of ~w\nDOnt spill ~w\n", [[CurrentReg|Active], DontSpill]), %% Find a spill candidate (one of the active): %% The register with the longest live-range. {NewActive, SpillCandidate} = butlast_last(Active), SpillStartpoint = active_startpoint(SpillCandidate) , SpillEndpoint = active_endpoint(SpillCandidate) , SpillName = active_name(SpillCandidate), SpillPhysName = active_reg(SpillCandidate), case SpillEndpoint > CurrentEndpoint of true -> %% There is an already allocated register that has %% a longer live-range than the current register. case can_spill(SpillName, DontSpill, Target) and (SpillStartpoint =< CurrentStartpoint) of false -> {NewAlloc, NewActive2} = spill(CurrentReg, CurrentEndpoint, CurrentStartpoint, NewActive, Alloc, SpillIndex, DontSpill, Target), {NewAlloc, add_active(SpillEndpoint, SpillStartpoint, SpillPhysName, SpillName, NewActive2)}; true -> %% It is not precoloured... or have too short liverange %% Allocate SpillCandidate to spill-slot SpillIndex SpillAlloc = spillalloc(active_name(SpillCandidate), SpillIndex, Alloc), %% Allocated the current register to the physical register %% used by the spill candidate. NewAlloc = alloc(CurrentReg, SpillPhysName, SpillAlloc), %% Add the current register to the active registers NewActive2 = add_active(CurrentEndpoint, CurrentStartpoint, SpillPhysName, CurrentReg, NewActive), {NewAlloc, NewActive2} end; false -> %% The current register has the longest live-range. case can_spill(CurrentReg, DontSpill, Target) of false -> %% Cannot spill a precoloured register {NewAlloc, NewActive2} = spill(SpillName, SpillEndpoint, SpillStartpoint, NewActive, Alloc, SpillIndex, DontSpill, Target), NewActive3 = add_active(CurrentEndpoint, CurrentStartpoint, SpillPhysName, CurrentReg, NewActive2), {NewAlloc, NewActive3}; true -> %% It is not precoloured... %% Allocate the current register to spill-slot SpillIndex {spillalloc(CurrentReg, SpillIndex, Alloc), Active} end end; spill(CurrentReg, _CurrentEndpoint, _CurrentStartpoint, [], Alloc, SpillIndex, DontSpill, Target) -> case can_spill(CurrentReg, DontSpill, Target) of false -> %% Can't spill current! ?error_msg("Can't allocate registers\n",[]), ?EXIT({cannot_allocate_regs}); true -> %% Can spill current. %% Allocate the current register to spill-slot SpillIndex {spillalloc(CurrentReg, SpillIndex, Alloc), []} end. can_spill(Name, DontSpill, Target) -> (Name < DontSpill) and (not is_precoloured(Name, Target)). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% %% D A T A S T R U C T U R E S %% %% & %% %% A U X I L I A R Y F U N C T I O N S %% %% %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% The "allocation datastructure" %% %% This is an order list of register names paired with their allocations. %% {Name, Allocation} %% The allocation is either {reg, physical register} or %% {spill, spill index} %% %% --------------------------------------------------------------------- empty_allocation() -> []. alloc(Name,Reg,[{Name,_}|A]) -> [{Name,{reg,Reg}}|A]; alloc(Name,Reg,[{Name2,Binding}|Bindings]) when Name > Name2 -> [{Name2,Binding}|alloc(Name,Reg,Bindings)]; alloc(Name,Reg,Bindings) -> [{Name,{reg,Reg}}|Bindings]. spillalloc(Name,N,[{Name,_}|A]) -> ?debug_msg("Spilled ~w\n",[Name]), [{Name,{spill,N}}|A]; spillalloc(Name,N,[{Name2,Binding}|Bindings]) when Name > Name2 -> [{Name2,Binding}|spillalloc(Name,N,Bindings)]; spillalloc(Name,N,Bindings) -> [{Name,{spill,N}}|Bindings]. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% butlast_last([X]) -> {[],X}; butlast_last([X|Y]) -> {L,Last} = butlast_last(Y), {[X|L],Last}. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% The active datastructure. %% Keeps tracks of currently active (allocated) physical registers. %% It is sorted on end points in the intervals %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% add_active(Endpoint, StartPoint, PhysReg, RegName, [{P1,R1,O1,S1}|Active]) when P1 < Endpoint -> [{P1,R1,O1,S1}|add_active(Endpoint, StartPoint, PhysReg, RegName, Active)]; add_active(Endpoint, StartPoint, PhysReg, RegName, Active) -> [{Endpoint, PhysReg, RegName, StartPoint}|Active]. active_reg({_,PhysReg,_,_}) -> PhysReg. active_endpoint({EndPoint,_,_,_}) -> EndPoint. active_startpoint({_,_,_,StartPoint}) -> StartPoint. active_name({_,_,RegName,_}) -> RegName. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% The Interval data structure. %% %% %%- - - - - - - - - - - - - - - - - - - - - - - - %% mk_interval(Name, Start, End) -> %% {Name, Start, End}. endpoint({_R,_S,Endpoint}) -> Endpoint. startpoint({_R,Startpoint,_E}) -> Startpoint. reg({RegName,_S,_E}) -> RegName. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% The Intervals data structure. sort_on_start(I) -> lists:keysort(2, I). -ifdef(gb_intervals). empty_interval(_) -> gb_trees:empty(). interval_to_list(Intervals) -> lists:flatten( lists:map( fun({T, I}) when list(I) -> lists:map( fun ({none, End}) -> {T,End,End}; ({Beg, none}) -> {T,Beg, Beg} end, I); ({T,{B,E}}) -> {T, B, E} end, gb_trees:to_list(Intervals))). add_use_point([Temp|Temps],Pos,Intervals) -> %% Extend the old interval... NewInterval = case gb_trees:lookup(Temp, Intervals) of %% This temp has an old interval... {value, Value} -> %% ... extend it. extend_interval(Pos, Value); %% This is the first time we see this temp... none -> %% ... create a new interval {Pos, Pos} end, %% Add or update the extended interval. Intervals2 = gb_trees:enter(Temp, NewInterval, Intervals), %% Add the rest of teh temporaries. add_use_point(Temps, Pos, Intervals2); add_use_point([], _, I) -> %% No more to add return the interval. I. add_def_point([Temp|Temps],Pos,Intervals) -> %% Extend the old interval... NewInterval = case gb_trees:lookup(Temp, Intervals) of %% This temp has an old interval... {value, Value} -> %% ... extend it. extend_interval(Pos, Value); %% This is the first time we see this temp... none -> %% ... create a new interval {Pos, Pos} end, %% Add or update the extended interval. Intervals2 = gb_trees:enter(Temp, NewInterval, Intervals), %% Add the rest of the temporaries. add_def_point(Temps, Pos, Intervals2); add_def_point([], _, I) -> %% No more to add return the interval. I. extend_interval(Pos, {Beginning, End}) -> %% If this position occures before the beginning %% of the interval, then extend the beginning to %% this position. NewBeginning = erlang:min(Pos, Beginning), %% If this position occures after the end %% of the interval, then extend the end to %% this position. NewEnd = erlang:max(Pos, End), {NewBeginning, NewEnd}. -else. %% isdef gb_intervals empty_interval(N) -> hipe_vectors:new(N, none). interval_to_list(Intervals) -> add_indices(hipe_vectors:vector_to_list(Intervals),0). add_indices([{B,E}|Xs],N) -> [{N,B,E}|add_indices(Xs,N+1)]; add_indices([List|Xs],N) when is_list(List) -> flatten(List,N,Xs); add_indices([none|Xs],N) -> add_indices(Xs,N+1); add_indices([],_N) -> []. flatten([{none, End}|Rest], N, More) -> [{N,End,End} | flatten(Rest, N, More)]; flatten([{Beg, none}|Rest], N ,More) -> [{N,Beg,Beg} | flatten(Rest, N, More)]; flatten([],N,More) -> add_indices(More,N+1). add_use_point([Temp|Temps],Pos,Intervals) -> %% Extend the old interval... NewInterval = case hipe_vectors:get(Intervals, Temp) of %% This is the first time we see this temp... none -> %% ... create a new interval {Pos, Pos}; %% This temp has an old interval... Value -> %% ... extend it. extend_interval(Pos, Value) end, %% Add or update the extended interval. Intervals2 = hipe_vectors:set(Intervals, Temp, NewInterval), %% Add the rest of the temporaries. add_use_point(Temps, Pos, Intervals2); add_use_point([], _, I) -> %% No more to add return the interval. I. add_def_point([Temp|Temps],Pos,Intervals) -> %% Extend the old interval... NewInterval = case hipe_vectors:get(Intervals, Temp) of %% This is the first time we see this temp... none -> %% ... create a new interval {Pos, Pos}; %% This temp has an old interval... Value -> %% ... extend it. extend_interval(Pos, Value) end, %% Add or update the extended interval. Intervals2 = hipe_vectors:set(Intervals, Temp, NewInterval), %% Add the rest of teh temporaries. add_def_point(Temps, Pos, Intervals2); add_def_point([], _, I) -> %% No more to add return the interval. I. extend_interval(Pos, {Beginning, End}) -> %% If this position occurs before the beginning of the interval, %% then extend the beginning to this position. NewBeginning = erlang:min(Pos, Beginning), %% If this position occures after the end %% of the interval, then extend the end to %% this position. NewEnd = erlang:max(Pos, End), {NewBeginning, NewEnd}. -endif. %% gb_intervals %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% The Freel data structure. %% %%- - - - - - - - - - - - - - - - - - - - - - - - is_free(R, Free) -> is_free(R, Free, []). is_free(R, [{R,_}|Rest], Acc) -> {true, lists:reverse(Acc, Rest)}; is_free(R, [X|Rs],Acc) -> is_free(R, Rs, [X|Acc]); is_free(_, [], _) -> false. exists_free_register(Start, Regs) -> exists_free_register(Start, Regs, []). exists_free_register(Start, [{Phys, Start0}|Rest], Acc) when Start > Start0 -> {true, Phys, lists:reverse(Acc, Rest)}; exists_free_register(Start, [Free|Rest], Acc) -> exists_free_register(Start, Rest, [Free|Acc]); exists_free_register(_, [], _) -> false. create_freeregs([Phys|Rest]) -> [{Phys,-1}|create_freeregs(Rest)]; create_freeregs([]) -> []. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% Interface to external functions. %% XXX: Make this efficient somehow... %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% liveness(CFG, Target) -> Target:analyze(CFG). bb(CFG, L, Target) -> Target:bb(CFG,L). livein(Liveness,L, Target) -> regnames(Target:livein(Liveness,L), Target). liveout(Liveness,L, Target) -> regnames(Target:liveout(Liveness,L), Target). uses(I, Target) -> regnames(Target:uses(I), Target). defines(I, Target) -> regnames(Target:defines(I), Target). is_precoloured(R, Target) -> Target:is_precoloured(R). is_global(R, Target) -> Target:is_global(R). physical_name(R, Target) -> Target:physical_name(R). regnames(Regs, Target) -> [Target:reg_nr(X) || X <- Regs]. arg_vars(CFG, Target) -> Target:args(CFG). is_arg(Reg, Target) -> Target:is_arg(Reg).