%%% -*- 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.
%%%
%%% - apply temp -> reg/spill map from RA

-ifdef(HIPE_AMD64).
-define(HIPE_X86_RA_FINALISE,	hipe_amd64_ra_finalise).
-define(HIPE_X86_REGISTERS,	hipe_amd64_registers).
-define(HIPE_X86_X87,		hipe_amd64_x87).
-define(HIPE_X86_SSE2,		hipe_amd64_sse2).
-define(IF_HAS_SSE2(Expr),	Expr).
-else.
-define(HIPE_X86_RA_FINALISE,	hipe_x86_ra_finalise).
-define(HIPE_X86_REGISTERS,	hipe_x86_registers).
-define(HIPE_X86_X87,		hipe_x86_x87).
-define(IF_HAS_SSE2(Expr),).
-endif.

-module(?HIPE_X86_RA_FINALISE).
-export([finalise/4]).
-include("../x86/hipe_x86.hrl").

finalise(CFG0, TempMap, FpMap, Options) ->
  CFG1 = finalise_ra(CFG0, TempMap, FpMap, Options),
  case proplists:get_bool(x87, Options) of
    true ->
      ?HIPE_X86_X87:map(CFG1);
    _ ->
      case
	proplists:get_bool(inline_fp, Options)
	and (proplists:get_value(regalloc, Options) =:= linear_scan)
      of
	%% Ugly, but required to avoid Dialyzer complaints about "Unknown
	%% function" hipe_x86_sse2:map/1
	?IF_HAS_SSE2(true ->
			?HIPE_X86_SSE2:map(CFG1);)
	false ->
	  CFG1
      end
  end.

%%%
%%% Finalise the temp->reg/spill mapping.
%%% (XXX: maybe this should be merged with the main pass,
%%% but I just want this to work now)
%%%

finalise_ra(CFG, [], [], _Options) ->
  CFG;
finalise_ra(CFG, TempMap, FpMap, Options) ->
  {_, SpillLimit} = hipe_gensym:var_range(x86),
  Map = mk_ra_map(TempMap, SpillLimit),
  FpMap0 = mk_ra_map_fp(FpMap, SpillLimit, Options),
  hipe_x86_cfg:map_bbs(fun(_Lbl, BB) -> ra_bb(BB, Map, FpMap0) end, CFG).

ra_bb(BB, Map, FpMap) ->
  hipe_bb:code_update(BB, ra_code(hipe_bb:code(BB), Map, FpMap)).

ra_code(Code, Map, FpMap) ->
  [ra_insn(I, Map, FpMap) || I <- Code].

ra_insn(I, Map, FpMap) ->
  case I of
    #alu{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#alu{src=Src,dst=Dst};
    #call{} ->
      I;
    #cmovcc{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#cmovcc{src=Src,dst=Dst};
    #cmp{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#cmp{src=Src,dst=Dst};
    #comment{} ->
      I;
    #fmove{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map, FpMap),
      Dst = ra_opnd(Dst0, Map, FpMap),
      I#fmove{src=Src,dst=Dst};
    #fp_unop{arg=Arg0} ->
      Arg = ra_opnd(Arg0, Map, FpMap),
      I#fp_unop{arg=Arg};
    #fp_binop{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map, FpMap),
      Dst = ra_opnd(Dst0, Map, FpMap),
      I#fp_binop{src=Src,dst=Dst};
    #imul{src=Src0,temp=Temp0} ->
      Src = ra_opnd(Src0, Map),
      Temp = ra_temp(Temp0, Map),
      I#imul{src=Src,temp=Temp};
    #jcc{} ->
      I;
    #jmp_fun{'fun'=Fun0} ->
      Fun = ra_opnd(Fun0, Map),
      I#jmp_fun{'fun'=Fun};
    #jmp_label{} ->
      I;
    #jmp_switch{temp=Temp0,jtab=JTab0} ->
      Temp = ra_opnd(Temp0, Map),
      JTab = ra_opnd(JTab0, Map),      
      I#jmp_switch{temp=Temp,jtab=JTab};
    #label{} ->
      I;
    #lea{mem=Mem0,temp=Temp0} ->
      Mem = ra_mem(Mem0, Map),
      Temp = ra_temp(Temp0, Map),
      I#lea{mem=Mem,temp=Temp};
    #move{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#move{src=Src,dst=Dst};
    #move64{dst=Dst0} ->
      Dst = ra_opnd(Dst0, Map),
      I#move64{dst=Dst};
    #movsx{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#movsx{src=Src,dst=Dst};
    #movzx{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#movzx{src=Src,dst=Dst};
    #pseudo_call{'fun'=Fun0} ->
      Fun = ra_opnd(Fun0, Map),
      I#pseudo_call{'fun'=Fun};
    #pseudo_jcc{} ->
      I;
    #pseudo_spill_fmove{src=Src0, temp=Temp0, dst=Dst0} ->
      Src = ra_opnd(Src0, Map, FpMap),
      Temp = ra_opnd(Temp0, Map, FpMap),
      Dst = ra_opnd(Dst0, Map, FpMap),
      I#pseudo_spill_fmove{src=Src, temp=Temp, dst=Dst};
    #pseudo_spill_move{src=Src0, temp=Temp0, dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Temp = ra_opnd(Temp0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#pseudo_spill_move{src=Src, temp=Temp, dst=Dst};
    #pseudo_tailcall{'fun'=Fun0,stkargs=StkArgs0} ->
      Fun = ra_opnd(Fun0, Map),
      StkArgs = ra_args(StkArgs0, Map),
      I#pseudo_tailcall{'fun'=Fun,stkargs=StkArgs};
    #pseudo_tailcall_prepare{} ->
      I;
    #push{src=Src0} ->
      Src = ra_opnd(Src0, Map),
      I#push{src=Src};
    #ret{} ->
      I;
    #shift{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#shift{src=Src,dst=Dst};
    #test{src=Src0,dst=Dst0} ->
      Src = ra_opnd(Src0, Map),
      Dst = ra_opnd(Dst0, Map),
      I#test{src=Src,dst=Dst};
    _ ->
      exit({?MODULE,ra_insn,I})
  end.

ra_args(Args, Map) ->
  [ra_opnd(Opnd, Map) || Opnd <- Args].

ra_opnd(Opnd, Map) ->
  ra_opnd(Opnd, Map, gb_trees:empty()).
ra_opnd(Opnd, Map, FpMap) ->
  case Opnd of
    #x86_temp{} -> ra_temp(Opnd, Map, FpMap);
    #x86_mem{} -> ra_mem(Opnd, Map);
    _ -> Opnd
  end.

ra_mem(Mem, Map) ->
  #x86_mem{base=Base0,off=Off0} = Mem,
  Base = ra_opnd(Base0, Map),
  Off = ra_opnd(Off0, Map),
  Mem#x86_mem{base=Base,off=Off}.

ra_temp(Temp, Map) ->
  ra_temp(Temp, Map, gb_trees:empty()).

ra_temp(Temp, Map, FpMap) ->
  Reg = hipe_x86:temp_reg(Temp),
  case hipe_x86:temp_type(Temp) of
    double ->
      ra_temp_double(Temp, Reg, FpMap);
    _->
      case ?HIPE_X86_REGISTERS:is_precoloured(Reg) of
	true ->
	  Temp;
	_ ->
	  case gb_trees:lookup(Reg, Map) of
	    {value,NewReg} -> Temp#x86_temp{reg=NewReg};
	    _ -> Temp
	  end
      end
  end.

-ifdef(HIPE_AMD64).
ra_temp_double(Temp, Reg, FpMap) ->
  case hipe_amd64_registers:is_precoloured_sse2(Reg) of
    true ->
      Temp;
    _ ->
      case gb_trees:lookup(Reg, FpMap) of
	{value,NewReg} -> Temp#x86_temp{reg=NewReg};
	_ -> Temp
      end
  end.
-else.
ra_temp_double(Temp, Reg, FpMap) ->
  case gb_trees:lookup(Reg, FpMap) of
    {value,NewReg} ->
      case hipe_x86_registers:is_precoloured_x87(NewReg) of
	true -> hipe_x86:mk_fpreg(NewReg);
	false ->
	  Temp#x86_temp{reg=NewReg}
      end;
    _ ->
      Temp
  end.
-endif.

mk_ra_map(TempMap, SpillLimit) ->
  %% Build a partial map from pseudo to reg or spill.
  %% Spills are represented as pseudos with indices above SpillLimit.
  %% (I'd prefer to use negative indices, but that breaks
  %% ?HIPE_X86_REGISTERS:is_precoloured/1.)
  %% The frame mapping proper is unchanged, since spills look just like
  %% ordinary (un-allocated) pseudos.
  lists:foldl(fun(MapLet, Map) ->
		  {Key,Val} = conv_ra_maplet(MapLet, SpillLimit,
					     is_precoloured),
		  gb_trees:insert(Key, Val, Map)
	      end,
	      gb_trees:empty(),
	      TempMap).

conv_ra_maplet({From,To}, SpillLimit, IsPrecoloured)
  when is_integer(From), From =< SpillLimit ->
  %% From should be a pseudo, or a hard reg mapped to itself.
  case ?HIPE_X86_REGISTERS:IsPrecoloured(From) of
    false -> ok;
    _ -> To = {reg, From}, ok
  end,
  %% end of From check
  case To of
    {reg, NewReg} when is_integer(NewReg) ->
      %% NewReg should be a hard reg, or a pseudo mapped
      %% to itself (formals are handled this way).
      true = (?HIPE_X86_REGISTERS:IsPrecoloured(NewReg) orelse From =:= NewReg),
      {From, NewReg};
    {spill, SpillIndex} when is_integer(SpillIndex), SpillIndex >= 0 ->
      ToTempNum = SpillLimit+SpillIndex+1,
      MaxTempNum = hipe_gensym:get_var(x86),
      if MaxTempNum >= ToTempNum -> ok;
	 true -> hipe_gensym:set_var(x86, ToTempNum)
      end,
      {From, ToTempNum}
  end.

mk_ra_map_x87(FpMap, SpillLimit) ->
  lists:foldl(fun(MapLet, Map) ->
		  {Key,Val} = conv_ra_maplet(MapLet, SpillLimit,
					     is_precoloured_x87),
		  gb_trees:insert(Key, Val, Map)
	      end,
	      gb_trees:empty(),
	      FpMap).

-ifdef(HIPE_AMD64).
mk_ra_map_sse2(FpMap, SpillLimit) ->
  lists:foldl(fun(MapLet, Map) ->
		  {Key,Val} = conv_ra_maplet(MapLet, SpillLimit,
					     is_precoloured_sse2),
		  gb_trees:insert(Key, Val, Map)
	      end,
	      gb_trees:empty(),
	      FpMap).

mk_ra_map_fp(FpMap, SpillLimit, Options) ->
  case proplists:get_bool(x87, Options) of
    true  -> mk_ra_map_x87(FpMap, SpillLimit);
    false -> mk_ra_map_sse2(FpMap, SpillLimit)
  end.
-else.
mk_ra_map_fp(FpMap, SpillLimit, _Options) ->
  mk_ra_map_x87(FpMap, SpillLimit).
-endif.

-ifdef(notdef).
conv_ra_maplet_fp(MapLet = {From,To}, SpillLimit) ->
  %% From should be a pseudo
  if is_integer(From), From =< SpillLimit -> [];
     true -> exit({?MODULE,conv_ra_maplet_fp,MapLet})
  end,
  %% end of From check
  case To of
    {reg, NewReg} ->
      case hipe_x86_registers:is_precoloured_x87(NewReg) of
	true-> [];
	false -> exit({?MODULE,conv_ra_maplet_fp,MapLet})
      end,
      %% end of NewReg check.
      {From, NewReg};
    {spill, SpillIndex} ->
      %% SpillIndex should be >= 0.
      if is_integer(SpillIndex), SpillIndex >= 0 -> [];
	 true -> exit({?MODULE,conv_ra_maplet_fp,MapLet})
      end,
      %% end of SpillIndex check
      ToTempNum = SpillLimit+SpillIndex+1,
      MaxTempNum = hipe_gensym:get_var(x86),
      if MaxTempNum >= ToTempNum -> [];
	 true -> hipe_gensym:set_var(x86, ToTempNum)
      end,
      {From, ToTempNum};
    _ -> exit({?MODULE,conv_ra_maplet_fp,MapLet})
  end.
-endif.