{
    $Id$
    Copyright (c) 1998-2002 by Florian Klaempfl

    This unit exports some help routines for the code generation

    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.

 ****************************************************************************
}
{# Some helpers for the code generator.
}
unit cgbase;

{$i fpcdefs.inc}

  interface

    uses
      { common }
      cclasses,
      { global }
      globtype,globals,verbose,
      { symtable }
      symconst,symtype,symdef,symsym,
      { aasm }
      cpubase,cpuinfo,cginfo,aasmbase,aasmtai
      ;


    type
      tprocinfoflag=(
        {# procedure uses asm }
        pi_uses_asm,
        {# procedure does a call }
        pi_do_call,
        {# procedure has a try statement = no register optimization }
        pi_uses_exceptions,
        {# procedure is declared as @var(assembler), don't optimize}
        pi_is_assembler,
        {# procedure contains data which needs to be finalized }
        pi_needs_implicit_finally
      );
      tprocinfoflags=set of tprocinfoflag;

    type
       {# This object gives information on the current routine being
          compiled.
       }
       tprocinfo = class(tlinkedlistitem)
          { pointer to parent in nested procedures }
          parent : tprocinfo;
          {# the definition of the routine itself }
          procdef : tprocdef;
          { file location of begin of procedure }
          entrypos  : tfileposinfo;
          { file location of end of procedure }
          exitpos   : tfileposinfo;
          { local switches at begin of procedure }
          entryswitches : tlocalswitches;
          { local switches at end of procedure }
          exitswitches  : tlocalswitches;

          { Size of the parameters on the stack }
          para_stack_size : longint;

          {# some collected informations about the procedure
             see pi_xxxx constants above
          }
          flags : tprocinfoflags;

          { register used as frame pointer }
          framepointer : tregister;

          { Holds the reference used to store alll saved registers. }
          save_regs_ref : treference;

          { label to leave the sub routine }
          aktexitlabel : tasmlabel;

          {# The code for the routine itself, excluding entry and
             exit code. This is a linked list of tai classes.
          }
          aktproccode : taasmoutput;
          { Data (like jump tables) that belongs to this routine }
          aktlocaldata : taasmoutput;

          constructor create(aparent:tprocinfo);virtual;
          destructor destroy;override;

          { Allocate framepointer so it can not be used by the
            register allocator }
          procedure allocate_framepointer_reg;virtual;

          procedure allocate_push_parasize(size:longint);virtual;

          function calc_stackframe_size:longint;virtual;

          { Does the necessary stuff before a procedure body is compiled }
          procedure handle_body_start;virtual;

          { This procedure is called after the pass 1 of the subroutine body is done.
            Here the address fix ups to generate code for the body must be done.
          }
          procedure after_pass1;virtual;
       end;

       pregvarinfo = ^tregvarinfo;
       tregvarinfo = record
          regvars : array[1..maxvarregs] of tvarsym;
          regvars_para : array[1..maxvarregs] of boolean;
          regvars_refs : array[1..maxvarregs] of longint;

          fpuregvars : array[1..maxfpuvarregs] of tvarsym;
          fpuregvars_para : array[1..maxfpuvarregs] of boolean;
          fpuregvars_refs : array[1..maxfpuvarregs] of longint;
       end;

       tcprocinfo = class of tprocinfo;

    var
       cprocinfo : tcprocinfo;
       {# information about the current sub routine being parsed (@var(pprocinfo))}
       current_procinfo : tprocinfo;

       { labels for BREAK and CONTINUE }
       aktbreaklabel,aktcontinuelabel : tasmlabel;

       { label when the result is true or false }
       truelabel,falselabel : tasmlabel;

       {# true, if there was an error while code generation occurs }
       codegenerror : boolean;

       { save the size of pushed parameter, needed for aligning }
       pushedparasize : longint;

    { message calls with codegenerror support }
    procedure cgmessage(t : longint);
    procedure cgmessage1(t : longint;const s : string);
    procedure cgmessage2(t : longint;const s1,s2 : string);
    procedure cgmessage3(t : longint;const s1,s2,s3 : string);
    procedure CGMessagePos(const pos:tfileposinfo;t:longint);
    procedure CGMessagePos1(const pos:tfileposinfo;t:longint;const s1:string);
    procedure CGMessagePos2(const pos:tfileposinfo;t:longint;const s1,s2:string);
    procedure CGMessagePos3(const pos:tfileposinfo;t:longint;const s1,s2,s3:string);

    { initialize respectively terminates the code generator }
    { for a new module or procedure                      }
    procedure codegen_newmodule;
    procedure codegen_donemodule;

    {# From a definition return the abstract code generator size enum. It is
       to note that the value returned can be @var(OS_NO) }
    function def_cgsize(def: tdef): tcgsize;
    {# From a constant numeric value, return the abstract code generator
       size.
    }
    function int_cgsize(const a: aword): tcgsize;

    {# return the inverse condition of opcmp }
    function inverse_opcmp(opcmp: topcmp): topcmp;

    {# return whether op is commutative }
    function commutativeop(op: topcg): boolean;


implementation

     uses
        cutils,systems,
        cresstr,
        tgobj,rgobj,
        defutil,
        fmodule
        ,symbase,paramgr
        ;


{*****************************************************************************
            override the message calls to set codegenerror
*****************************************************************************}

    procedure cgmessage(t : longint);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.Message(t);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;

    procedure cgmessage1(t : longint;const s : string);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.Message1(t,s);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;

    procedure cgmessage2(t : longint;const s1,s2 : string);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.Message2(t,s1,s2);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;

    procedure cgmessage3(t : longint;const s1,s2,s3 : string);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.Message3(t,s1,s2,s3);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;


    procedure cgmessagepos(const pos:tfileposinfo;t : longint);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.MessagePos(pos,t);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;

    procedure cgmessagepos1(const pos:tfileposinfo;t : longint;const s1 : string);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.MessagePos1(pos,t,s1);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;

    procedure cgmessagepos2(const pos:tfileposinfo;t : longint;const s1,s2 : string);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.MessagePos2(pos,t,s1,s2);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;

    procedure cgmessagepos3(const pos:tfileposinfo;t : longint;const s1,s2,s3 : string);
      var
         olderrorcount : longint;
      begin
         if not(codegenerror) then
           begin
              olderrorcount:=Errorcount;
              verbose.MessagePos3(pos,t,s1,s2,s3);
              codegenerror:=olderrorcount<>Errorcount;
           end;
      end;


{****************************************************************************
                                 TProcInfo
****************************************************************************}

    constructor tprocinfo.create(aparent:tprocinfo);
      begin
        parent:=aparent;
        procdef:=nil;
        para_stack_size:=0;
        flags:=[];
        framepointer:=NR_FRAME_POINTER_REG;
        { asmlists }
        aktproccode:=Taasmoutput.Create;
        aktlocaldata:=Taasmoutput.Create;
        reference_reset(save_regs_ref);
        { labels }
        objectlibrary.getlabel(aktexitlabel);
      end;


    destructor tprocinfo.destroy;
      begin
         aktproccode.free;
         aktlocaldata.free;
      end;


    procedure tprocinfo.allocate_framepointer_reg;
      begin
        if framepointer=NR_FRAME_POINTER_REG then
          begin
            { Make sure the register allocator won't allocate registers
              into ebp }
            include(rg.used_in_proc_int,RS_FRAME_POINTER_REG);
            exclude(rg.unusedregsint,RS_FRAME_POINTER_REG);
          end;
      end;


    procedure tprocinfo.allocate_push_parasize(size:longint);
      begin
      end;


    function tprocinfo.calc_stackframe_size:longint;
      var
        _align : longint;
      begin
        { align to 4 bytes at least
          otherwise all those subl $2,%esp are meaningless PM }
        _align:=target_info.alignment.localalignmin;
        if _align<4 then
          _align:=4;
        result:=Align(tg.direction*tg.lasttemp,_align);
      end;


    procedure tprocinfo.handle_body_start;
      begin
      end;


    procedure tprocinfo.after_pass1;
      begin
      end;


{*****************************************************************************
         initialize/terminate the codegen for procedure and modules
*****************************************************************************}

    procedure codegen_newmodule;
      begin
         exprasmlist:=taasmoutput.create;
         datasegment:=taasmoutput.create;
         codesegment:=taasmoutput.create;
         bsssegment:=taasmoutput.create;
         debuglist:=taasmoutput.create;
         withdebuglist:=taasmoutput.create;
         consts:=taasmoutput.create;
         rttilist:=taasmoutput.create;
         ResourceStringList:=Nil;
         importssection:=nil;
         exportssection:=nil;
         resourcesection:=nil;
         { resourcestrings }
         ResourceStrings:=TResourceStrings.Create;
         { use the librarydata from current_module }
         objectlibrary:=current_module.librarydata;
      end;


    procedure codegen_donemodule;
{$ifdef MEMDEBUG}
      var
        d : tmemdebug;
{$endif}
      begin
{$ifdef MEMDEBUG}
         d:=tmemdebug.create(current_module.modulename^+' - asmlists');
{$endif}
         exprasmlist.free;
         codesegment.free;
         bsssegment.free;
         datasegment.free;
         debuglist.free;
         withdebuglist.free;
         consts.free;
         rttilist.free;
         if assigned(ResourceStringList) then
          ResourceStringList.free;
         if assigned(importssection) then
          importssection.free;
         if assigned(exportssection) then
          exportssection.free;
         if assigned(resourcesection) then
          resourcesection.free;
{$ifdef MEMDEBUG}
         d.free;
{$endif}
         { resource strings }
         ResourceStrings.free;
         objectlibrary:=nil;
      end;


    function def_cgsize(def: tdef): tcgsize;
      begin
        case def.deftype of
          orddef,
          enumdef,
          setdef:
            begin
              result := int_cgsize(def.size);
              if is_signed(def) then
                result := tcgsize(ord(result)+(ord(OS_S8)-ord(OS_8)));
            end;
          classrefdef,
          pointerdef:
            result := OS_ADDR;
          procvardef:
            begin
              if tprocvardef(def).is_methodpointer and
                 (not tprocvardef(def).is_addressonly) then
                result := OS_64
              else
                result := OS_ADDR;
            end;
          stringdef :
            begin
              if is_ansistring(def) or is_widestring(def) then
                result := OS_ADDR
              else
                result := OS_NO;
            end;
          objectdef :
            begin
              if is_class_or_interface(def) then
                result := OS_ADDR
              else
                result := OS_NO;
            end;
          floatdef:
            result := tfloat2tcgsize[tfloatdef(def).typ];
          recorddef :
            result:=int_cgsize(def.size);
          arraydef :
            begin
              if not is_special_array(def) then
                result := int_cgsize(def.size)
              else
                begin
                  if is_dynamic_array(def) then
                    result := OS_ADDR
                  else
                    result := OS_NO;
                end;
            end;
          else
            begin
              { undefined size }
              result:=OS_NO;
            end;
        end;
      end;


    function int_cgsize(const a: aword): tcgsize;
      begin
        if a > 8 then
          begin
            int_cgsize := OS_NO;
            exit;
          end;
        case byte(a) of
          1 :
            result := OS_8;
          2 :
            result := OS_16;
          3,4 :
            result := OS_32;
          5..8 :
            result := OS_64;
        end;
      end;


    function inverse_opcmp(opcmp: topcmp): topcmp;
      const
        list: array[TOpCmp] of TOpCmp =
          (OC_NONE,OC_NE,OC_LTE,OC_GTE,OC_LT,OC_GT,OC_EQ,OC_A,OC_AE,
           OC_B,OC_BE);
      begin
        inverse_opcmp := list[opcmp];
      end;


    function commutativeop(op: topcg): boolean;
      const
        list: array[topcg] of boolean =
          (true,true,true,false,false,true,true,false,false,
           true,false,false,false,false,true);
      begin
        commutativeop := list[op];
      end;

end.
{
  $Log$
  Revision 1.66  2003-09-28 17:55:03  peter
    * parent framepointer changed to hidden parameter
    * tloadparentfpnode added

  Revision 1.65  2003/09/25 21:25:13  peter
    * remove allocate_intterupt_parameter, allocation is platform
      dependent and needs to be done in create_paraloc_info

  Revision 1.64  2003/09/23 17:56:05  peter
    * locals and paras are allocated in the code generation
    * tvarsym.localloc contains the location of para/local when
      generating code for the current procedure

  Revision 1.63  2003/09/14 19:18:10  peter
    * remove obsolete code already in comments

  Revision 1.62  2003/09/07 22:09:34  peter
    * preparations for different default calling conventions
    * various RA fixes

  Revision 1.61  2003/09/03 15:55:00  peter
    * NEWRA branch merged

  Revision 1.60.2.1  2003/08/29 17:28:59  peter
    * next batch of updates

  Revision 1.60  2003/08/26 12:43:02  peter
    * methodpointer fixes

  Revision 1.59  2003/08/20 17:48:49  peter
    * fixed stackalloc to not allocate localst.datasize twice
    * order of stackalloc code fixed for implicit init/final

  Revision 1.58  2003/08/11 21:18:20  peter
    * start of sparc support for newra

  Revision 1.57  2003/07/06 17:58:22  peter
    * framepointer fixes for sparc
    * parent framepointer code more generic

  Revision 1.56  2003/06/13 21:19:30  peter
    * current_procdef removed, use current_procinfo.procdef instead

  Revision 1.55  2003/06/12 16:43:07  peter
    * newra compiles for sparc

  Revision 1.54  2003/06/09 12:23:29  peter
    * init/final of procedure data splitted from genentrycode
    * use asmnode getposition to insert final at the correct position
      als for the implicit try...finally

  Revision 1.53  2003/06/02 21:42:05  jonas
    * function results can now also be regvars
    - removed tprocinfo.return_offset, never use it again since it's invalid
      if the result is a regvar

  Revision 1.52  2003/05/26 21:17:17  peter
    * procinlinenode removed
    * aktexit2label removed, fast exit removed
    + tcallnode.inlined_pass_2 added

  Revision 1.51  2003/05/23 14:27:35  peter
    * remove some unit dependencies
    * current_procinfo changes to store more info

  Revision 1.50  2003/05/16 20:54:12  jonas
    - undid previous commit, it wasn't necessary

  Revision 1.49  2003/05/16 20:00:39  jonas
    * powerpc nested procedure fixes, should work completely now if all
      local variables of the parent procedure are declared before the
      nested procedures are declared

  Revision 1.48  2003/05/15 18:58:53  peter
    * removed selfpointer_offset, vmtpointer_offset
    * tvarsym.adjusted_address
    * address in localsymtable is now in the real direction
    * removed some obsolete globals

  Revision 1.47  2003/05/13 19:14:41  peter
    * failn removed
    * inherited result code check moven to pexpr

  Revision 1.46  2003/05/09 17:47:02  peter
    * self moved to hidden parameter
    * removed hdisposen,hnewn,selfn

  Revision 1.45  2003/04/27 11:21:32  peter
    * aktprocdef renamed to current_procinfo.procdef
    * procinfo renamed to current_procinfo
    * procinfo will now be stored in current_module so it can be
      cleaned up properly
    * gen_main_procsym changed to create_main_proc and release_main_proc
      to also generate a tprocinfo structure
    * fixed unit implicit initfinal

  Revision 1.44  2003/04/27 07:29:50  peter
    * current_procinfo.procdef cleanup, current_procdef is now always nil when parsing
      a new procdef declaration
    * aktprocsym removed
    * lexlevel removed, use symtable.symtablelevel instead
    * implicit init/final code uses the normal genentry/genexit
    * funcret state checking updated for new funcret handling

  Revision 1.43  2003/04/26 00:31:42  peter
    * set return_offset moved to after_header

  Revision 1.42  2003/04/25 20:59:33  peter
    * removed funcretn,funcretsym, function result is now in varsym
      and aliases for result and function name are added using absolutesym
    * vs_hidden parameter for funcret passed in parameter
    * vs_hidden fixes
    * writenode changed to printnode and released from extdebug
    * -vp option added to generate a tree.log with the nodetree
    * nicer printnode for statements, callnode

  Revision 1.41  2003/04/23 12:35:34  florian
    * fixed several issues with powerpc
    + applied a patch from Jonas for nested function calls (PowerPC only)
    * ...

  Revision 1.40  2003/04/22 13:47:08  peter
    * fixed C style array of const
    * fixed C array passing
    * fixed left to right with high parameters

  Revision 1.39  2003/04/05 21:09:31  jonas
    * several ppc/generic result offset related fixes. The "normal" result
      offset seems now to be calculated correctly and a lot of duplicate
      calculations have been removed. Nested functions accessing the parent's
      function result don't work at all though :(

  Revision 1.38  2003/03/28 19:16:56  peter
    * generic constructor working for i386
    * remove fixed self register
    * esi added as address register for i386

  Revision 1.37  2003/03/20 17:51:45  peter
    * dynamic arrays have size OS_ADDR

  Revision 1.36  2003/01/08 18:43:56  daniel
   * Tregister changed into a record

  Revision 1.35  2003/01/01 21:04:48  peter
    * removed unused method

  Revision 1.34  2002/11/25 17:43:16  peter
    * splitted defbase in defutil,symutil,defcmp
    * merged isconvertable and is_equal into compare_defs(_ext)
    * made operator search faster by walking the list only once

  Revision 1.33  2002/11/18 17:31:54  peter
    * pass proccalloption to ret_in_xxx and push_xxx functions

  Revision 1.32  2002/10/05 12:43:23  carl
    * fixes for Delphi 6 compilation
     (warning : Some features do not work under Delphi)

  Revision 1.31  2002/10/03 21:20:19  carl
    * range check error fix

  Revision 1.30  2002/09/30 07:00:44  florian
    * fixes to common code to get the alpha compiler compiled applied

  Revision 1.29  2002/09/07 19:35:45  florian
    + tcg.direction is used now

  Revision 1.28  2002/09/07 15:25:01  peter
    * old logs removed and tabs fixed

  Revision 1.27  2002/09/05 19:29:42  peter
    * memdebug enhancements

  Revision 1.26  2002/08/18 20:06:23  peter
    * inlining is now also allowed in interface
    * renamed write/load to ppuwrite/ppuload
    * tnode storing in ppu
    * nld,ncon,nbas are already updated for storing in ppu

  Revision 1.25  2002/08/17 09:23:33  florian
    * first part of procinfo rewrite

  Revision 1.24  2002/08/11 14:32:26  peter
    * renamed current_library to objectlibrary

  Revision 1.23  2002/08/11 13:24:11  peter
    * saving of asmsymbols in ppu supported
    * asmsymbollist global is removed and moved into a new class
      tasmlibrarydata that will hold the info of a .a file which
      corresponds with a single module. Added librarydata to tmodule
      to keep the library info stored for the module. In the future the
      objectfiles will also be stored to the tasmlibrarydata class
    * all getlabel/newasmsymbol and friends are moved to the new class

  Revision 1.22  2002/08/06 20:55:20  florian
    * first part of ppc calling conventions fix

  Revision 1.21  2002/08/05 18:27:48  carl
    + more more more documentation
    + first version include/exclude (can't test though, not enough scratch for i386 :()...

  Revision 1.20  2002/08/04 19:06:41  carl
    + added generic exception support (still does not work!)
    + more documentation

  Revision 1.19  2002/07/20 11:57:53  florian
    * types.pas renamed to defbase.pas because D6 contains a types
      unit so this would conflicts if D6 programms are compiled
    + Willamette/SSE2 instructions to assembler added

  Revision 1.18  2002/07/01 18:46:22  peter
    * internal linker
    * reorganized aasm layer

  Revision 1.17  2002/05/20 13:30:40  carl
  * bugfix of hdisponen (base must be set, not index)
  * more portability fixes

  Revision 1.16  2002/05/18 13:34:05  peter
    * readded missing revisions

  Revision 1.15  2002/05/16 19:46:35  carl
  + defines.inc -> fpcdefs.inc to avoid conflicts if compiling by hand
  + try to fix temp allocation (still in ifdef)
  + generic constructor calls
  + start of tassembler / tmodulebase class cleanup

  Revision 1.13  2002/04/25 20:16:38  peter
    * moved more routines from cga/n386util

  Revision 1.12  2002/04/21 15:28:06  carl
  - remove duplicate constants
  - move some constants to cginfo

  Revision 1.11  2002/04/20 21:32:23  carl
  + generic FPC_CHECKPOINTER
  + first parameter offset in stack now portable
  * rename some constants
  + move some cpu stuff to other units
  - remove unused constents
  * fix stacksize for some targets
  * fix generic size problems which depend now on EXTEND_SIZE constant

  Revision 1.10  2002/04/07 09:13:39  carl
  + documentation
  - remove unused variables

  Revision 1.9  2002/04/04 19:05:54  peter
    * removed unused units
    * use tlocation.size in cg.a_*loc*() routines

  Revision 1.8  2002/04/02 17:11:27  peter
    * tlocation,treference update
    * LOC_CONSTANT added for better constant handling
    * secondadd splitted in multiple routines
    * location_force_reg added for loading a location to a register
      of a specified size
    * secondassignment parses now first the right and then the left node
      (this is compatible with Kylix). This saves a lot of push/pop especially
      with string operations
    * adapted some routines to use the new cg methods

  Revision 1.7  2002/03/31 20:26:33  jonas
    + a_loadfpu_* and a_loadmm_* methods in tcg
    * register allocation is now handled by a class and is mostly processor
      independent (+rgobj.pas and i386/rgcpu.pas)
    * temp allocation is now handled by a class (+tgobj.pas, -i386\tgcpu.pas)
    * some small improvements and fixes to the optimizer
    * some register allocation fixes
    * some fpuvaroffset fixes in the unary minus node
    * push/popusedregisters is now called rg.save/restoreusedregisters and
      (for i386) uses temps instead of push/pop's when using -Op3 (that code is
      also better optimizable)
    * fixed and optimized register saving/restoring for new/dispose nodes
    * LOC_FPU locations now also require their "register" field to be set to
      R_ST, not R_ST0 (the latter is used for LOC_CFPUREGISTER locations only)
    - list field removed of the tnode class because it's not used currently
      and can cause hard-to-find bugs

}