%% -*- erlang-indent-level: 2 -*-
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2001-2013. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%% =====================================================================
%% @doc
%% <pre>
%% 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.)
%% </pre>
%% @end
%%
%% History : * 2000-04-07 Erik Johansson ([email protected]): 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]).
%%-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:
%% <ol>
%% <li> Calculate live-ranges for all registers.</li>
%% <li> 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.</li>
%% <li> Perform a linear scan allocation over the live intervals.</li>
%% </ol>
%% @end
%%- - - - - - - - - - - - - - - - - - - - - - - -
regalloc(CFG, PhysRegs, Entrypoints, SpillIndex, DontSpill, Options, Target) ->
?debug_msg("LinearScan: ~w\n", [erlang:statistics(runtime)]),
%% Step 1: Calculate liveness (Call external implementation.)
Liveness = liveness(CFG, Target),
?debug_msg("liveness (done)~w\n", [erlang:statistics(runtime)]),
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)]),
Allocation = allocate(Intervals, PhysRegs, SpillIndex, DontSpill, Target),
?debug_msg("allocation (done) ~w\n", [erlang:statistics(runtime)]),
Allocation.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% %%
%% 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).
