freepascal.compiler/rtl/m68k/m68k.inc

{
    $Id$
    This file is part of the Free Pascal run time library.
    Copyright (c) 1993,97 by Carl-Eric Codere,
    member of the Free Pascal development team.

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    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.

 **********************************************************************}
{****************************************************************************

      m68k.inc : Processor dependent implementation of system unit
                 For Motorola 680x0 Processor.

*****************************************************************************}

{****************************************************************************}
{   Credit where credit is due:                                              }
{   -Some of the copy routines taken from the Atari dlib source code:        }
{     Dale Schumacher (alias: Dalnefre')  [email protected]                    }
{     399 Beacon Ave. St. Paul, MN 55104,USA                                 }
{   -Some of the routines taken from the freeware ATARI Sozobon C compiler   }
{      1988 by Sozobon, Limited.  Author: Johann Ruegg (freeware)            }
{  Thanks to all these people wherever they maybe today!                     }
{****************************************************************************}


    { Don't call the following routines directly. }
 Procedure Hlt;[public,alias: 'FPC_HALT_ERROR'];
 { called by code generator on run-time errors. }
 { on entry contains d0 = error code.           }
 var
  b:byte; { only byte is used... }
 begin
  asm
     move.b d0,b
  end;
     HandleError(b);
 end;




   Procedure FillChar(var x;count:longint;value:byte);[public,alias: 'FPC_FILL_OBJECT'];
   begin
     asm
      move.l 8(a6), a0      { destination                   }
      move.l 12(a6), d1     { number of bytes to fill       }
      move.b 16(a6),d0      { fill data                     }
      cmpi.l #65535, d1     { check, if this is a word move }
      ble    @LMEMSET3      { use fast dbra mode            }
      bra @LMEMSET2
    @LMEMSET1:
      move.b d0,(a0)+
    @LMEMSET2:
      subq.l #1,d1
      cmp.b #-1,d1
      bne  @LMEMSET1
      bra @LMEMSET5        { finished slow mode , exit     }

    @LMEMSET4:             { fast loop mode section 68010+ }
      move.b d0,(a0)+
    @LMEMSET3:
      dbra d1,@LMEMSET4

    @LMEMSET5:
     end ['d0','d1','a0'];
   end;

   Procedure FillObject(var x; count: longint; value: byte);
   begin
     asm
      move.l 8(a6), a0      { destination                   }
      move.l 12(a6), d1     { number of bytes to fill       }
      move.w 16(a6),d0      { fill data                     }
      cmp.l  #65535, d1     { check, if this is a word move }
      ble    @LMEMSET3      { use fast dbra mode            }
      bra @LMEMSET2
    @LMEMSET1:
      move.b d0,(a0)+
    @LMEMSET2:
      subq.l #1,d1
      cmp.b #-1,d1
      bne  @LMEMSET1
      bra @LMEMSET5        { finished slow mode , exit     }

    @LMEMSET4:             { fast loop mode section 68010+ }
      move.b d0,(a0)+
    @LMEMSET3:
      dbra d1,@LMEMSET4

    @LMEMSET5:
     end ['d0','d1','a0'];
   end;

    procedure int_help_constructor;[public,alias:'FPC_HELP_CONSTRUCTOR'];

      begin
         asm
            { Entry without preamble, since we need the ESP of the
              constructor }
            { Stack (relative to %ebp):
                12 Self
                8 VMT-Address
                4 main programm-Addr
                0 %ebp
            }
            { do we have to initialize self  }
            { we just need to check for zero }
            move.l    a5,d0
            tst.l     d0      { set flags }
            bne       @LHC_4

            { get memory, but save register first }
            { temporary variable }
            subq.l #4,sp
            move.l sp,a5
            { Save Registers }
            movem.l d0-a7,-(sp)
            { Memory size }
            move.l 8(a6),a0
            move.l (a0),-(sp)
            { push method pointer }
            move.l a5,-(sp)
            jsr FPC_GETMEM
            { Restore all registers in the correct order }
            movem.l (sp)+,d0-a7
            { Memory position to a5 }
            move.l (a5),a5
            addq.l  #4,sp
            { If no memory available : fail() }
            move.l a5,d0
            tst.l  d0         { set flags for a5 }
            beq    @LHC_5
            { init self for the constructor }
            move.l a5,12(a6)
         @LHC_4:
            { is there a VMT address ? }
            move.l 8(a6),d0
            or.l   d0,d0
            bne @LHC_7
            { In case the constructor doesn't do anything, the Zero-Flag }
            { can't be put, because this calls Fail() }
            add.l  #1,d0
            rts
         @LHC_7:
            { set zero inside the object }
            { Save Registers }
            movem.l d0-a7,-(sp)
            move.w  #0,-(sp)

            move.l  8(a6),a0
            move.l  (a0),-(sp)
            move.l  a5,-(sp)
            {                }
            jsr  FPC_FILLOBJECT
            { Restore all registers in the correct order }
            movem.l (sp)+,d0-a7
            { set the VMT address for the new created object }
{$ifdef OBJECTVMTOFFSET}
      { the offset is in %edi since the calling and has not been changed !! }
            move.l 8(a6),d1
            move.l d1,(a5,d0.l)
{$else OBJECTVMTOFFSET}
            move.l 8(a6),d0
            move.l d0,(a5)
{$endif OBJECTVMTOFFSET}
            or.l d0,d0
         @LHC_5:
            rts
         end;
      end;

    procedure help_fail;

      begin
         asm
         end;
      end;

    procedure int_help_destructor;[public,alias:'FPC_HELP_DESTRUCTOR'];

      begin
         asm
            { Stack (relative to %ebp):
                12 Self
                8 VMT-Address
                4 Main program-Addr
                0 %ebp
            }
            { temporary Variable }
            subq.l #4,sp
            move.l sp,d6
            { Save Registers }
            movem.l d0-a7,-(sp)

            move.l 8(a6),d0         { Get the address of the vmt }
            or.l   d0,d0            { Check if there is a vmt    }
            beq    @LHD_3
            { Yes, get size from SELF! }
            move.l 12(a6),a0
            { get VMT-pointer (from Self) to %ebx }
            move.l (a0),a1
            { And put size on the Stack }
            move.l (a1),-(sp)
            { SELF }
            { I think for precaution }
            { that we should clear the VMT here }
            clr.l (a0)
            { get address of local variable into  }
            { address register                    }
            move.l d6,a1
            move.l a0,(a1)
            move.l a1,-(sp)
            jsr    FPC_FREEMEM
         @LHD_3:
            { Restore all registers in the correct order }
            movem.l (sp)+,d0-a7
            add.l #4,sp
            rts
         end;
      end;

  procedure new_class;assembler;[public,alias:'FPC_NEW_CLASS'];

  asm
     { create class ? }
     move.l 8(a6), d0
     tst.l  d0
     { check for nil... }
     beq    @NEW_CLASS1

     { a5 contains vmt }
     move.l a5,-(sp)
     { call newinstance (class method!) }
     jsr 16(a5)
     { new instance returns a pointer to the new created }
     { instance in d0                                    }
     { load a5  and insert self                          }
     move.l d0,8(a6)
     move.l d0,a5
     bra    @end
  @NEW_CLASS1:
     move.l a5,8(a6)
  @end:
  end;



  procedure dispose_class;assembler;[public,alias:'FPC_DISPOSE_CLASS'];

  asm
     { destroy class ? }
     move.l 8(a6),d0
     { save self }
     move.l a5,8(a6)
     tst.l  d0
     beq    @DISPOSE_CLASS
     { no inherited call }
     move.l (a5),d0
     { push self }
     move.l a5,-(sp)
     { call freeinstance }
     move.l d0,a0
     jsr    20(a0)
  @DISPOSE_CLASS:
     { load self }
     move.l 8(a6),a5
  end;

  { checks for a correct vmt pointer }
  procedure int_check_object;assembler;[public,alias:'FPC_CHECK_OBJECT'];
  { ON ENTRY: a0 -> Pointer to the VMT                  }
  {   Nota: All registers must be preserved including   }
  {   A0 itself!                                        }
  asm
     move.l   d0,-(sp)
     tst.l    a0
     { z flag set if zero }
     beq      @co_re

     move.l   (a0),d0
     add.l    4(a0),d0
     bne      @co_re
     bra      @end
@co_re:
     move.l   (sp)+,d0
     move.b   #210,d0
     jsr      FPC_HALT_ERROR
@end:
     move.l   (sp)+,d0
  end;


    function get_frame : longint; assembler;
      asm
              move.l a6,d0
      end;


    function get_caller_addr(framebp:longint):longint;
      begin
         asm
            move.l FRAMEBP,a0
            cmp.l #0,a0
            beq @Lnul_address
            move.l 4(a0),a0
         @Lnul_address:
            move.l a0,@RESULT
         end ['a0'];
      end;

    function get_caller_frame(framebp:longint):longint;

      begin
         asm
            move.l FRAMEBP,a0
            cmp.l  #0,a0
            beq    @Lnul_frame
            move.l (a0),a0
         @Lnul_frame:
            move.l a0,@RESULT
         end ['a0'];
      end;

{    procedure strcopy(dstr,sstr : pointer;len : longint);[public,alias: 'STRCOPY'];}
     procedure strcopy; assembler;[public,alias: 'FPC_STRCOPY'];
    {---------------------------------------------------}
    { Low-level routine to copy a string to another     }
    { string with maximum length. Never call directly!  }
    { On Entry:                                         }
    {     a1.l = string to copy to                      }
    {     a0.l = source string                          }
    {     d0.l = maximum length of copy                 }
    { registers destroyed: a0,a1,d0,d1                  }
    {---------------------------------------------------}
         asm
{            move.l 12(a6),a0
            move.l 16(a6),a1
            move.l 8(a6),d1 }
            move.l d0,d1

            move.b (a0)+,d0     { Get source length }
            and.w  #$ff,d0
            cmp.w  d1,d0        { This is a signed comparison! }
            ble    @LM4
            move.b d1,d0        { If longer than maximum size of target, cut
                                  source length }
         @LM4:
            andi.l #$ff,d0     { zero extend d0-byte }
            move.l d0,d1       { save length to copy }
            move.b d0,(a1)+    { save new length     }
            { Check if copying length is zero - if so then }
            { exit without copying anything.               }
            tst.b  d1
            beq    @Lend
            bra    @LMSTRCOPY55
         @LMSTRCOPY56:         { 68010 Fast loop mode }
            move.b (a0)+,(a1)+
         @LMSTRCOPY55:
            dbra  d1,@LMSTRCOPY56
         @Lend:
      end;

    { Concatenate Strings }
    { PARAMETERS ARE REVERSED COMPARED TO NORMAL! }
    { therefore online assembler may not parse the params as normal }
    procedure strconcat(s1,s2 : pointer);[public,alias: 'STRCONCAT'];

      begin
         asm
          move.b  #255,d0
          move.l  s1,a0                { a0 = destination }
          move.l  s2,a1                { a1 = source      }
          sub.b   (a0),d0              {  copyl:= 255 -length(s1)    }
          move.b  (a1),d6
          and.w   #$ff,d0              { Sign flags are checked!     }
          and.w   #$ff,d6
          cmp.w   d6,d0                { if copyl > length(s2) then  }
          ble     @Lcontinue
          move.b  (a1),d0              {  copyl:=length(s2)          }
    @Lcontinue:
          move.b  (a0),d6
          and.l   #$ff,d6
          lea     1(a0,d6),a0          { s1[length(s1)+1]            }
          add.l   #1,a1                { s2[1]                       }
          move.b  d0,d6
          { Check if copying length is zero - if so then }
          { exit without copying anything.               }
          tst.b  d6
          beq    @Lend
          bra    @ALoop
    @Loop:
          move.b  (a1)+,(a0)+          { s1[i] := s2[i];             }
    @ALoop:
          dbra    d6,@Loop
          move.l  s1,a0
          add.b   d0,(a0)              { change to new string length }
    @Lend:
         end ['d0','d1','a0','a1','d6'];
      end;

    { Compares strings }
    { DO NOT CALL directly.                                 }
    {   a0 = pointer to first string to compare             }
    {   a1 = pointer to second string to compare            }
    {   ALL FLAGS are set appropriately.                    }
    {    ZF = strings are equal                             }
    { REGISTERS DESTROYED: a0, a1, d0, d1, d6               }
    procedure strcmp; assembler;[public,alias:'FPC_STRCMP'];
     asm
            move.b (a0)+,d0     { Get length of first string  }
            move.b (a1)+,d6     { Get length of 2nd string    }

            move.b  d6,d1      { Save length of string for final compare   }

            cmp.b  d0,d6        { Get shortest string length   }
            ble    @LSTRCONCAT1
            move.b d0,d6       { Set length to shortest string }

         @LSTRCONCAT1:
            tst.b  d6          { Both strings have a length of zero, exit }
            beq    @LSTRCONCAT2

            andi.l  #$ff,d6


            subq.l  #1,d6      { subtract first attempt                    }
            { if value is -1 then don't loop and just compare lengths of   }
            { both strings before exiting.                                 }
            bmi     @LSTRCONCAT2
            or.l    d0,d0      { Make sure to set Zerfo flag to 0          }
         @LSTRCONCAT5:
            { Workaroung for GAS v.134 bug }
            {  old: cmp.b (a1)+,(a0)+      }
            cmpm.b  (a1)+,(a0)+
         @LSTRCONCAT4:
            dbne    d6,@LSTRCONCAT5   { Repeat until not equal }
            bne     @LSTRCONCAT3
          @LSTRCONCAT2:
            { If length of both string are equal }
            { Then set zero flag                 }
            cmp.b   d1,d0   { Compare length - set flag if equal length strings }
         @LSTRCONCAT3:
     end;


  Function strpas(p: pchar): string;
  { only 255 first characters are actually copied. }
   var
    counter : byte;
    str: string;
  Begin
     counter := 0;
     str := '';
     while (ord(p[counter]) <> 0) and (counter < 255) do
     begin
        counter:=counter+1;
        str[counter] := char(p[counter-1]);
     end;
     str[0] := char(counter);
     strpas := str;
  end;

  function strlen(p : pchar) : longint;
  var
     counter : longint;
  Begin
       counter := 0;
       repeat
          counter:=counter+1;
       until ord(p[counter]) = 0;
       strlen := counter;
  end;


   procedure move(var source;var dest;count : longint);
   { base pointer+8 = source                  }
   { base pointer+12 = destination            }
   { base pointer+16 = number of bytes to move}
   begin
     asm
      clr.l      d0
      move.l   16(a6),d0   {  number of bytes }
    @LMOVE0:
      move.l   12(a6),a1   {  destination          }
      move.l   8(a6),a0      {  source               }

      cmpi.l #65535, d0     { check, if this is a word move }
      ble    @LMEMSET00     { use fast dbra mode 68010+     }

      cmp.l      a0,a1         {  check copy direction }
      bls      @LMOVE4
      add.l      d0,a0         { move pointers to end  }
      add.l      d0,a1
      bra     @LMOVE2
    @LMOVE1:
      move.b   -(a0),-(a1)   {  (s < d) copy loop }
    @LMOVE2:
      subq.l    #1,d0
      cmpi.l    #-1,d0
      bne       @LMOVE1
      bra       @LMOVE5
    @LMOVE3:
      move.b  (a0)+,(a1)+  { (s >= d) copy loop }
    @LMOVE4:
      subq.l    #1,d0
      cmpi.l    #-1,d0
      bne       @LMOVE3
      bra       @LMOVE5

    @LMEMSET00:            { use fast loop mode 68010+ }
      cmp.l      a0,a1         {  check copy direction }
      bls      @LMOVE04
      add.l      d0,a0         { move pointers to end  }
      add.l      d0,a1
      bra     @LMOVE02
    @LMOVE01:
      move.b   -(a0),-(a1)   {  (s < d) copy loop }
    @LMOVE02:
      dbra      d0,@LMOVE01
      bra       @LMOVE5
    @LMOVE03:
      move.b  (a0)+,(a1)+  { (s >= d) copy loop }
    @LMOVE04:
      dbra      d0,@LMOVE03
    { end fast loop mode }
    @LMOVE5:
    end ['d0','a0','a1'];
   end;


    procedure fillword(var x;count : longint;value : word);

      begin
     asm
      move.l 8(a6), a0      { destination             }
      move.l 12(a6), d1     { number of bytes to fill }
      move.w 16(a6),d0      { fill data               }
      bra @LMEMSET21
    @LMEMSET11:
      move.w d0,(a0)+
    @LMEMSET21:
      subq.l #1,d1
      cmp.b #-1,d1
      bne  @LMEMSET11
     end ['d0','d1','a0'];
   end;


    function abs(l : longint) : longint;

      begin
         asm
            move.l 8(a6),d0
            tst.l  d0
            bpl @LMABS1
            neg.l d0
         @LMABS1:
            move.l d0,@RESULT
         end ['d0'];
      end;

    function odd(l : longint) : boolean;

      begin
        if (l and $01) = $01 then
          odd := TRUE
        else
          odd := FALSE;
      end;

    function sqr(l : longint) : longint;

      begin
         sqr := l*l;
      end;

    procedure int_str(l : longint;var s : string);

      var
        value: longint;
        negative: boolean;

      begin
         negative := false;
         s:='';
         { Workaround: }
         if l=$80000000 then
           begin
              s:='-2147483648';
              exit;
           end;
        { handle case where l = 0 }
         if l = 0 then
         begin
           s:='0';
           exit;
         end;
         If l < 0 then
         begin
             negative := true;
             value:=abs(l);
         end
         else
             value:=l;
       { handle non-zero case }
       while value>0 do
         begin
            s:=char((value mod 10)+ord('0'))+s;
            value := value div 10;
         end;
         if negative then
           s := '-' + s;
      end;


Function Sptr : Longint;
begin
  asm
    move.l sp,d0
    add.l  #8,d0
    move.l d0,@RESULT
  end ['d0'];
end;




 Procedure BoundsCheck;assembler;[public,alias:'FPC_RE_BOUNDS_CHECK'];
 { called by code generator with R+ state to    }
 { determine if a range check occured.          }
 { Only in 68000 mode, in 68020 mode this is    }
 { inline.                                      }
 { On Entry:                                    }
 {   A1 = address contaning min and max indexes }
 {   D0 = value of current index to check.      }
 asm
  cmp.l   (A1),D0        { lower bound ...    }
  bmi     @rebounderr    { is index lower ... }
  add.l   #4,A1
  cmp.l   (A1),D0
  bmi     @reboundend
  beq     @reboundend
@rebounderr:
  move.l  #201,d0
  jsr     FPC_HALT_ERROR
@reboundend:
 end;

{****************************************************************************
                                 IoCheck
****************************************************************************}

procedure int_iocheck(addr : longint);[public,alias: {$ifdef FPCNAMES}'FPC_'+{$endif}'IOCHECK'];
var
  l : longint;
begin
  asm
        movem.l d0-a7,-(sp)
  end;
  if InOutRes<>0 then
   begin
     l:=InOutRes;
     InOutRes:=0;
     If ErrorProc<>Nil then
       TErrorProc(Errorproc)(l,pointer(addr));
{$ifndef RTLLITE}
     writeln('IO-Error ',l,' at 0x',HexStr(addr,8));
{$endif}
     Halt(byte(l));
   end;
  asm
        movem.l (sp)+,d0-a7
  end;
end;

{
  $Log$
  Revision 1.13  1998-10-15 11:35:03  pierre
   + first step of variable vmt offset
     offset is stored in R_EDI (R_D0)
     if objectvmtoffset is defined

  Revision 1.12  1998/10/13 08:00:06  pierre
    * some bugs related to FPC_ prefix fixed
    * problems with pbyte sometimes defined and sometimes not for rttip.inc solved

  Revision 1.11  1998/09/14 10:48:29  peter
    * FPC_ names
    * Heap manager is now system independent

  Revision 1.10  1998/08/17 12:26:04  carl
    + simple cleanup of comments

  Revision 1.9  1998/07/30 13:26:14  michael
  + Added support for ErrorProc variable. All internal functions are required
    to call HandleError instead of runerror from now on.
    This is necessary for exception support.

  Revision 1.8  1998/07/10 11:02:41  peter
    * support_fixed, becuase fixed is not 100% yet for the m68k

  Revision 1.7  1998/07/02 12:20:58  carl
    + Io-Error and overflow print erroraddr in hex now

  Revision 1.6  1998/07/01 14:25:57  carl
    * strconcat was copying one byte too much
    * strcopy bugfix was using signed comparison
    + STRCOPY uses register calling conventions
    * FillChar bugfix was loading a word instead of a byte
}