freepascal.compiler/compiler/powerpc/cpupara.pas

{
    $Id$
    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,
       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):longint;
          function parseparaloc(p : tparavarsym;const s : string) : boolean;override;
       end;

  implementation

    uses
       verbose,systems,
       defutil,
       cgutils;


    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) 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);
          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);

        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):longint;
      var
         stack_offset: longint;
         paralen: aint;
         nextintreg,nextfloatreg,nextmmreg, maxfpureg : tsuperregister;
         paradef : tdef;
         paraloc : pcgparalocation;
         i  : integer;
         hp : tparavarsym;
         loc : tcgloc;
         paracgsize: tcgsize;

(*
      procedure assignintreg;

        begin
          if nextintreg<=RS_R10 then
            begin
               paraloc^.loc:=LOC_REGISTER;
               paraloc^.register:=newreg(R_INTREGISTER,nextintreg,R_SUBNONE);
               inc(nextintreg);
               if target_info.abi=abi_powerpc_aix then
                 inc(stack_offset,4);
            end
          else
             begin
                paraloc^.loc:=LOC_REFERENCE;
                if (side = callerside) then
                  paraloc^.reference.index:=NR_STACK_POINTER_REG
                else
                  paraloc^.reference.index:=NR_R12;
                paraloc^.reference.offset:=stack_offset;
                inc(stack_offset,4);
            end;
        end;
*)

      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)];
                  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;
                          loc := getparaloc(paradef);
                          paracgsize:=def_cgsize(paradef);
                        end
                      else
                        begin
                          loc := LOC_REGISTER;
                          paracgsize := int_cgsize(paralen);
                        end;
                    end
                  else
                    begin
                      loc:=getparaloc(paradef);
                      paracgsize:=def_cgsize(paradef);
                      { for things like formaldef }
                      if (paracgsize=OS_NO) then
                        begin
                          paracgsize:=OS_ADDR;
                          paralen := tcgsize2size[OS_ADDR];
                        end;
                    end
                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 = recorddef) 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;
                      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,tcgsize2size[paraloc^.size]);
                    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
                         paraloc^.reference.index:=NR_R12;
                       paraloc^.reference.offset:=stack_offset;
                       inc(stack_offset,align(paralen,4));
                       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);
        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);
            { 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;


begin
   paramanager:=tppcparamanager.create;
end.
{
  $Log$
  Revision 1.89  2005-02-14 17:13:10  peter
    * truncate log

  Revision 1.88  2005/02/11 15:20:23  jonas
    * records which consist of only a union of one element have to be passed
      according to record parameter passing rules, not according to the rules
      of that item's type (change relevant to AIX abi only)

  Revision 1.87  2005/02/03 20:04:49  peter
    * push_addr_param must be defined per target

  Revision 1.86  2005/01/31 17:46:25  peter
    * fixed parseparaloc

  Revision 1.85  2005/01/20 17:47:01  peter
    * remove copy_value_on_stack and a_param_copy_ref

  Revision 1.84  2005/01/14 20:59:17  jonas
    * fixed overallocation of stack space for parameters under SYSV
      (introduced in one of my previous commits)
    * unified code of get_volatile_registers_fpu for SYSV and AIX

  Revision 1.83  2005/01/13 22:02:40  jonas
    * r2 can be used by the register allocator under Darwin
    * merged the initialisations of the fpu register allocator for AIX and
      SYSV

  Revision 1.82  2005/01/13 19:32:08  jonas
    * fixed copy_value_on_stack() for AIX abi
    + added support for passing empty record parameters

  Revision 1.81  2005/01/10 21:50:05  jonas
    + support for passing records in registers under darwin
    * tcgpara now also has an intsize field, which contains the size in
      bytes of the whole parameter

  Revision 1.80  2005/01/07 10:58:03  jonas
    * fixed stupid tregister/tsuperregister bug (type checking circumvented
      using explicit typecase), caused bug3523

  Revision 1.79  2005/01/06 02:13:03  karoly
    * more SysV call support stuff for MorphOS

}