{
    Copyright (c) 2002 by Florian Klaempfl

    PowerPC specific calling conventions

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 ****************************************************************************
}
unit cpupara;

{$i fpcdefs.inc}

  interface

    uses
       globtype,
       aasmtai,aasmdata,
       cpubase,
       symconst,symtype,symdef,symsym,
       paramgr,parabase,cgbase;

    type
       tppcparamanager = class(tparamanager)
          function get_volatile_registers_int(calloption : tproccalloption):tcpuregisterset;override;
          function get_volatile_registers_fpu(calloption : tproccalloption):tcpuregisterset;override;
          function push_addr_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;override;

          procedure getintparaloc(calloption : tproccalloption; nr : longint;var cgpara:TCGPara);override;
          function create_paraloc_info(p : tabstractprocdef; side: tcallercallee):longint;override;
          function create_varargs_paraloc_info(p : tabstractprocdef; varargspara:tvarargsparalist):longint;override;
          procedure create_funcretloc_info(p : tabstractprocdef; side: tcallercallee);
         private
          procedure init_values(var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword);
          function create_paraloc_info_intern(p : tabstractprocdef; side: tcallercallee; paras:tparalist;
              var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword; varargsparas: boolean):longint;
          function parseparaloc(p : tparavarsym;const s : string) : boolean;override;
       end;

  implementation

    uses
       verbose,systems,
       defutil,
       cgutils,
       procinfo,cpupi;


    function tppcparamanager.get_volatile_registers_int(calloption : tproccalloption):tcpuregisterset;
      begin
        if (target_info.system = system_powerpc_darwin) then
          result := [RS_R2..RS_R12]
        else
          result := [RS_R3..RS_R12];
      end;


    function tppcparamanager.get_volatile_registers_fpu(calloption : tproccalloption):tcpuregisterset;
      begin
        case target_info.abi of
          abi_powerpc_aix,
          abi_powerpc_sysv:
            result := [RS_F0..RS_F13];
          else
            internalerror(2003091401);
        end;
      end;


    procedure tppcparamanager.getintparaloc(calloption : tproccalloption; nr : longint;var cgpara:TCGPara);
      var
        paraloc : pcgparalocation;
      begin
        cgpara.reset;
        cgpara.size:=OS_INT;
        cgpara.intsize:=tcgsize2size[OS_INT];
        cgpara.alignment:=get_para_align(calloption);
        paraloc:=cgpara.add_location;
        with paraloc^ do
         begin
           size:=OS_INT;
           if (nr<=8) then
             begin
               if nr=0 then
                 internalerror(200309271);
               loc:=LOC_REGISTER;
               register:=newreg(R_INTREGISTER,RS_R2+nr,R_SUBWHOLE);
             end
           else
             begin
               loc:=LOC_REFERENCE;
               paraloc^.reference.index:=NR_STACK_POINTER_REG;
               if (target_info.abi <> abi_powerpc_aix) then
                 reference.offset:=sizeof(aint)*(nr-8)
               else
                 reference.offset:=sizeof(aint)*(nr);
             end;
          end;
      end;



    function getparaloc(p : tdef) : tcgloc;

      begin
         { Later, the LOC_REFERENCE is in most cases changed into LOC_REGISTER
           if push_addr_param for the def is true
         }
         case p.deftype of
            orddef:
              result:=LOC_REGISTER;
            floatdef:
              result:=LOC_FPUREGISTER;
            enumdef:
              result:=LOC_REGISTER;
            pointerdef:
              result:=LOC_REGISTER;
            formaldef:
              result:=LOC_REGISTER;
            classrefdef:
              result:=LOC_REGISTER;
            recorddef:
              if (target_info.abi<>abi_powerpc_aix) or
                 ((p.size >= 3) and
                  ((p.size mod 4) <> 0)) then
                result:=LOC_REFERENCE
              else
                result:=LOC_REGISTER;
            objectdef:
              if is_object(p) then
                result:=LOC_REFERENCE
              else
                result:=LOC_REGISTER;
            stringdef:
              if is_shortstring(p) or is_longstring(p) then
                result:=LOC_REFERENCE
              else
                result:=LOC_REGISTER;
            procvardef:
              if (po_methodpointer in tprocvardef(p).procoptions) then
                result:=LOC_REFERENCE
              else
                result:=LOC_REGISTER;
            filedef:
              result:=LOC_REGISTER;
            arraydef:
              result:=LOC_REFERENCE;
            setdef:
              if is_smallset(p) then
                result:=LOC_REGISTER
              else
                result:=LOC_REFERENCE;
            variantdef:
              result:=LOC_REFERENCE;
            { avoid problems with errornous definitions }
            errordef:
              result:=LOC_REGISTER;
            else
              internalerror(2002071001);
         end;
      end;


    function tppcparamanager.push_addr_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;
      begin
        result:=false;
        { var,out always require address }
        if varspez in [vs_var,vs_out] then
          begin
            result:=true;
            exit;
          end;
        case def.deftype of
          variantdef,
          formaldef :
            result:=true;
          recorddef:
            result :=
              (target_info.abi<>abi_powerpc_aix) or
              ((varspez = vs_const) and
               ((calloption = pocall_mwpascal) or
                (not (calloption in [pocall_cdecl,pocall_cppdecl]) and
                 (def.size > 8)
                )
               )
              );
          arraydef:
            result:=(tarraydef(def).highrange>=tarraydef(def).lowrange) or
                             is_open_array(def) or
                             is_array_of_const(def) or
                             is_array_constructor(def);
          objectdef :
            result:=is_object(def);
          setdef :
            result:=(tsetdef(def).settype<>smallset);
          stringdef :
            result:=tstringdef(def).string_typ in [st_shortstring,st_longstring];
          procvardef :
            result:=po_methodpointer in tprocvardef(def).procoptions;
        end;
      end;


    procedure tppcparamanager.init_values(var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword);
      begin
        case target_info.abi of
          abi_powerpc_aix:
            cur_stack_offset:=24;
          abi_powerpc_sysv:
            cur_stack_offset:=8;
          else
            internalerror(2003051901);
        end;
        curintreg:=RS_R3;
        curfloatreg:=RS_F1;
        curmmreg:=RS_M1;
      end;


    procedure tppcparamanager.create_funcretloc_info(p : tabstractprocdef; side: tcallercallee);
      var
        retcgsize  : tcgsize;
      begin
        { Constructors return self instead of a boolean }
        if (p.proctypeoption=potype_constructor) then
          retcgsize:=OS_ADDR
        else
          retcgsize:=def_cgsize(p.rettype.def);

        location_reset(p.funcretloc[side],LOC_INVALID,OS_NO);
        p.funcretloc[side].size:=retcgsize;
        { void has no location }
        if is_void(p.rettype.def) then
          begin
            p.funcretloc[side].loc:=LOC_VOID;
            exit;
          end;

        { Return in FPU register? }
        if p.rettype.def.deftype=floatdef then
          begin
            p.funcretloc[side].loc:=LOC_FPUREGISTER;
            p.funcretloc[side].register:=NR_FPU_RESULT_REG;
            p.funcretloc[side].size:=retcgsize;
          end
        else
         { Return in register? }
         if not ret_in_param(p.rettype.def,p.proccalloption) then
          begin
{$ifndef cpu64bit}
            if retcgsize in [OS_64,OS_S64] then
             begin
               { low 32bits }
               p.funcretloc[side].loc:=LOC_REGISTER;
               if side=callerside then
                 p.funcretloc[side].register64.reghi:=NR_FUNCTION_RESULT64_HIGH_REG
               else
                 p.funcretloc[side].register64.reghi:=NR_FUNCTION_RETURN64_HIGH_REG;
               { high 32bits }
               if side=callerside then
                 p.funcretloc[side].register64.reglo:=NR_FUNCTION_RESULT64_LOW_REG
               else
                 p.funcretloc[side].register64.reglo:=NR_FUNCTION_RETURN64_LOW_REG;
             end
            else
{$endif cpu64bit}
             begin
               p.funcretloc[side].loc:=LOC_REGISTER;
               p.funcretloc[side].size:=retcgsize;
               if side=callerside then
                 p.funcretloc[side].register:=newreg(R_INTREGISTER,RS_FUNCTION_RESULT_REG,cgsize2subreg(retcgsize))
               else
                 p.funcretloc[side].register:=newreg(R_INTREGISTER,RS_FUNCTION_RETURN_REG,cgsize2subreg(retcgsize));
             end;
          end
        else
          begin
            p.funcretloc[side].loc:=LOC_REFERENCE;
            p.funcretloc[side].size:=retcgsize;
          end;
      end;


    function tppcparamanager.create_paraloc_info(p : tabstractprocdef; side: tcallercallee):longint;

      var
        cur_stack_offset: aword;
        curintreg, curfloatreg, curmmreg: tsuperregister;
      begin
        init_values(curintreg,curfloatreg,curmmreg,cur_stack_offset);

        result := create_paraloc_info_intern(p,side,p.paras,curintreg,curfloatreg,curmmreg,cur_stack_offset,false);

        create_funcretloc_info(p,side);
      end;



    function tppcparamanager.create_paraloc_info_intern(p : tabstractprocdef; side: tcallercallee; paras:tparalist;
               var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword; varargsparas: boolean):longint;
      var
         stack_offset: longint;
         paralen: aint;
         nextintreg,nextfloatreg,nextmmreg, maxfpureg : tsuperregister;
         paradef : tdef;
         paraloc : pcgparalocation;
         i  : integer;
         hp : tparavarsym;
         loc : tcgloc;
         paracgsize: tcgsize;

      begin
{$ifdef extdebug}
         if po_explicitparaloc in p.procoptions then
           internalerror(200411141);
{$endif extdebug}

         result:=0;
         nextintreg := curintreg;
         nextfloatreg := curfloatreg;
         nextmmreg := curmmreg;
         stack_offset := cur_stack_offset;
         case target_info.abi of
           abi_powerpc_aix:
             maxfpureg := RS_F13;
           abi_powerpc_sysv:
             maxfpureg := RS_F8;
           else internalerror(2004070912);
         end;

          for i:=0 to paras.count-1 do
            begin
              hp:=tparavarsym(paras[i]);
              paradef := hp.vartype.def;
              { Syscall for Morphos can have already a paraloc set }
              if (vo_has_explicit_paraloc in hp.varoptions) then
                begin
                  if not(vo_is_syscall_lib in hp.varoptions) then
                    internalerror(200412153);
                  continue;
                end;
              hp.paraloc[side].reset;
              { currently only support C-style array of const }
              if (p.proccalloption in [pocall_cdecl,pocall_cppdecl]) and
                 is_array_of_const(paradef) then
                begin
                  paraloc:=hp.paraloc[side].add_location;
                  { hack: the paraloc must be valid, but is not actually used }
                  paraloc^.loc := LOC_REGISTER;
                  paraloc^.register := NR_R0;
                  paraloc^.size := OS_ADDR;
                  break;
                end;

              if (hp.varspez in [vs_var,vs_out]) or
                 push_addr_param(hp.varspez,paradef,p.proccalloption) or
                 is_open_array(paradef) or
                 is_array_of_const(paradef) then
                begin
                  paradef:=voidpointertype.def;
                  loc:=LOC_REGISTER;
                  paracgsize := OS_ADDR;
                  paralen := tcgsize2size[OS_ADDR];
                end
              else
                begin
                  if not is_special_array(paradef) then
                    paralen := paradef.size
                  else
                    paralen := tcgsize2size[def_cgsize(paradef)];
                  loc := getparaloc(paradef);
                  if (target_info.abi = abi_powerpc_aix) and
                     (paradef.deftype = recorddef) and
                     (hp.varspez in [vs_value,vs_const]) then
                    begin
                      { if a record has only one field and that field is }
                      { non-composite (not array or record), it must be  }
                      { passed according to the rules of that type.       }
                      if (trecorddef(hp.vartype.def).symtable.symindex.count = 1) and
                         (not trecorddef(hp.vartype.def).isunion) and
                         ((tabstractvarsym(trecorddef(hp.vartype.def).symtable.symindex.search(1)).vartype.def.deftype = floatdef) or
                          ((target_info.system = system_powerpc_darwin) and
                           (tabstractvarsym(trecorddef(hp.vartype.def).symtable.symindex.search(1)).vartype.def.deftype in [orddef,enumdef]))) then
                        begin
                          paradef :=
                           tabstractvarsym(trecorddef(hp.vartype.def).symtable.symindex.search(1)).vartype.def;
                          paracgsize:=def_cgsize(paradef);
                        end
                      else
                        begin
                          paracgsize := int_cgsize(paralen);
                        end;
                    end
                  else
                    begin
                      paracgsize:=def_cgsize(paradef);
                      { for things like formaldef }
                      if (paracgsize=OS_NO) then
                        begin
                          paracgsize:=OS_ADDR;
                          paralen := tcgsize2size[OS_ADDR];
                        end;
                    end
                end;

              if varargsparas and
                 (target_info.abi = abi_powerpc_aix) and
                 (paradef.deftype = floatdef) then
                begin
                  loc := LOC_REGISTER;
                  if paracgsize = OS_F64 then
                    paracgsize := OS_64
                  else
                    paracgsize := OS_32;
                end;

              hp.paraloc[side].alignment:=std_param_align;
              hp.paraloc[side].size:=paracgsize;
              hp.paraloc[side].intsize:=paralen;
              if (target_info.abi = abi_powerpc_aix) and
                 (paradef.deftype in [recorddef,arraydef]) then
                hp.paraloc[side].composite:=true;
{$ifndef cpu64bit}
              if (target_info.abi=abi_powerpc_sysv) and
                 is_64bit(paradef) and
                 odd(nextintreg-RS_R3) then
                inc(nextintreg);
{$endif not cpu64bit}
              if (paralen = 0) then
                if (paradef.deftype = recorddef) then
                  begin
                    paraloc:=hp.paraloc[side].add_location;
                    paraloc^.loc := LOC_VOID;
                  end
                else
                  internalerror(2005011310);
              { can become < 0 for e.g. 3-byte records }
              while (paralen > 0) do
                begin
                  paraloc:=hp.paraloc[side].add_location;
                  if (loc = LOC_REGISTER) and
                     (nextintreg <= RS_R10) then
                    begin
                      paraloc^.loc := loc;
                      { make sure we don't lose whether or not the type is signed }
                      if (paradef.deftype <> orddef) then
                        paracgsize := int_cgsize(paralen);
                      if (paracgsize in [OS_NO,OS_64,OS_S64]) then
                        paraloc^.size := OS_INT
                      else
                        paraloc^.size := paracgsize;
                      paraloc^.register:=newreg(R_INTREGISTER,nextintreg,R_SUBNONE);
                      inc(nextintreg);
                      dec(paralen,tcgsize2size[paraloc^.size]);
                      if target_info.abi=abi_powerpc_aix then
                        inc(stack_offset,align(tcgsize2size[paraloc^.size],4));
                    end
                  else if (loc = LOC_FPUREGISTER) and
                          (nextfloatreg <= maxfpureg) then
                    begin
                      paraloc^.loc:=loc;
                      paraloc^.size := paracgsize;
                      paraloc^.register:=newreg(R_FPUREGISTER,nextfloatreg,R_SUBWHOLE);
                      inc(nextfloatreg);
                      dec(paralen,tcgsize2size[paraloc^.size]);
                      { if nextfpureg > maxfpureg, all intregs are already used, since there }
                      { are less of those available for parameter passing in the AIX abi     }
                      if target_info.abi=abi_powerpc_aix then
{$ifndef cpu64bit}
                        if (paracgsize = OS_F32) then
                          begin
                            inc(stack_offset,4);
                            if (nextintreg < RS_R11) then
                              inc(nextintreg);
                          end
                        else
                          begin
                            inc(stack_offset,8);
                            if (nextintreg < RS_R10) then
                              inc(nextintreg,2)
                            else
                              nextintreg := RS_R11;
                          end;
{$else not cpu64bit}
                          begin
                            inc(stack_offset,tcgsize2size[paracgsize]);
                            if (nextintreg < RS_R11) then
                              inc(nextintreg);
                          end;
{$endif not cpu64bit}
                    end
                  else { LOC_REFERENCE }
                    begin
                       paraloc^.loc:=LOC_REFERENCE;
                       paraloc^.size:=int_cgsize(paralen);
                       if (side = callerside) then
                         paraloc^.reference.index:=NR_STACK_POINTER_REG
                       else
                         begin
                           paraloc^.reference.index:=NR_R12;
                           tppcprocinfo(current_procinfo).needs_frame_pointer := true;
                         end;
                       
                       if (target_info.abi = abi_powerpc_aix) and
                          (hp.paraloc[side].intsize < 3) then
                           paraloc^.reference.offset:=stack_offset+(4-paralen)
                       else
                         paraloc^.reference.offset:=stack_offset;

                       inc(stack_offset,align(paralen,4));
                       while (paralen > 0) and
                             (nextintreg < RS_R11) do
                          begin
                            inc(nextintreg);
                            dec(paralen,sizeof(aint));
                          end;
                       paralen := 0;
                    end;
                end;
            end;
         curintreg:=nextintreg;
         curfloatreg:=nextfloatreg;
         curmmreg:=nextmmreg;
         cur_stack_offset:=stack_offset;
         result:=stack_offset;
      end;


    function tppcparamanager.create_varargs_paraloc_info(p : tabstractprocdef; varargspara:tvarargsparalist):longint;
      var
        cur_stack_offset: aword;
        parasize, l: longint;
        curintreg, firstfloatreg, curfloatreg, curmmreg: tsuperregister;
        i : integer;
        hp: tparavarsym;
        paraloc: pcgparalocation;
      begin
        init_values(curintreg,curfloatreg,curmmreg,cur_stack_offset);
        firstfloatreg:=curfloatreg;

        result:=create_paraloc_info_intern(p,callerside,p.paras,curintreg,curfloatreg,curmmreg,cur_stack_offset, false);
        if (p.proccalloption in [pocall_cdecl,pocall_cppdecl]) then
          { just continue loading the parameters in the registers }
          begin
            result:=create_paraloc_info_intern(p,callerside,varargspara,curintreg,curfloatreg,curmmreg,cur_stack_offset,true);
            { varargs routines have to reserve at least 32 bytes for the AIX abi }
            if (target_info.abi = abi_powerpc_aix) and
               (result < 32) then
              result := 32;
           end
        else
          begin
            parasize:=cur_stack_offset;
            for i:=0 to varargspara.count-1 do
              begin
                hp:=tparavarsym(varargspara[i]);
                hp.paraloc[callerside].alignment:=4;
                paraloc:=hp.paraloc[callerside].add_location;
                paraloc^.loc:=LOC_REFERENCE;
                paraloc^.size:=def_cgsize(hp.vartype.def);
                paraloc^.reference.index:=NR_STACK_POINTER_REG;
                l:=push_size(hp.varspez,hp.vartype.def,p.proccalloption);
                paraloc^.reference.offset:=parasize;
                parasize:=parasize+l;
              end;
            result:=parasize;
          end;
        if curfloatreg<>firstfloatreg then
          include(varargspara.varargsinfo,va_uses_float_reg);
      end;


    function tppcparamanager.parseparaloc(p : tparavarsym;const s : string) : boolean;
      var
        paraloc : pcgparalocation;
        paracgsize : tcgsize;
      begin
        result:=false;
        case target_info.system of
          system_powerpc_morphos:
            begin
              paracgsize:=def_cgsize(p.vartype.def);
              p.paraloc[callerside].alignment:=4;
              p.paraloc[callerside].size:=paracgsize;
              p.paraloc[callerside].intsize:=tcgsize2size[paracgsize];
              paraloc:=p.paraloc[callerside].add_location;
              paraloc^.loc:=LOC_REFERENCE;
              paraloc^.size:=paracgsize;
              paraloc^.reference.index:=newreg(R_INTREGISTER,RS_R2,R_SUBWHOLE);
              { pattern is always uppercase'd }
              if s='D0' then
                paraloc^.reference.offset:=0
              else if s='D1' then
                paraloc^.reference.offset:=4
              else if s='D2' then
                paraloc^.reference.offset:=8
              else if s='D3' then
                paraloc^.reference.offset:=12
              else if s='D4' then
                paraloc^.reference.offset:=16
              else if s='D5' then
                paraloc^.reference.offset:=20
              else if s='D6' then
                paraloc^.reference.offset:=24
              else if s='D7' then
                paraloc^.reference.offset:=28
              else if s='A0' then
                paraloc^.reference.offset:=32
              else if s='A1' then
                paraloc^.reference.offset:=36
              else if s='A2' then
                paraloc^.reference.offset:=40
              else if s='A3' then
                paraloc^.reference.offset:=44
              else if s='A4' then
                paraloc^.reference.offset:=48
              else if s='A5' then
                paraloc^.reference.offset:=52
              { 'A6' (offset 56) is used by mossyscall as libbase, so API
                never passes parameters in it,
                Indeed, but this allows to declare libbase either explicitly
                or let the compiler insert it }
              else if s='A6' then
                paraloc^.reference.offset:=56
              { 'A7' is the stack pointer on 68k, can't be overwritten
                by API calls, so it has no offset }
              { 'R12' is special, used internally to support r12base sysv
                calling convention }
              else if s='R12' then
                begin
                  paraloc^.loc:=LOC_REGISTER;
                  paraloc^.size:=OS_ADDR;
                  paraloc^.register:=NR_R12;
                end
              else
                exit;

              { copy to callee side }
              p.paraloc[calleeside].add_location^:=paraloc^;
            end;
          else
            internalerror(200404182);
        end;
        result:=true;
      end;

{

    breaks e.g. tests/test/cg/tpara1

    procedure tppcparamanager.createtempparaloc(list: TAsmList;calloption : tproccalloption;parasym : tparavarsym;var cgpara:TCGPara);
      var
        paraloc : pcgparalocation;
      begin
        paraloc:=parasym.paraloc[callerside].location;
        { No need for temps when value is pushed }
        if assigned(paraloc) and
           (paraloc^.loc=LOC_REFERENCE) and
           (paraloc^.reference.index=NR_STACK_POINTER_REG) then
          duplicateparaloc(list,calloption,parasym,cgpara)
        else
          inherited createtempparaloc(list,calloption,parasym,cgpara);
      end;
}


begin
   paramanager:=tppcparamanager.create;
end.
