fpc/compiler/i8086/n8086cal.pas

98 lines
2.9 KiB
ObjectPascal

{
Copyright (c) 1998-2002 by Florian Klaempfl
Generate i8086 assembler for in call nodes
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 n8086cal;
{$i fpcdefs.inc}
interface
{ $define AnsiStrRef}
uses
nx86cal;
type
ti8086callnode = class(tx86callnode)
protected
procedure pop_parasize(pop_size:longint);override;
procedure extra_interrupt_code;override;
end;
implementation
uses
globtype,systems,
cutils,verbose,globals,
cgbase,cgutils,
cpubase,paramgr,
aasmtai,aasmdata,aasmcpu,
ncal,nbas,nmem,nld,ncnv,
cga,cgobj,cpuinfo;
{*****************************************************************************
TI8086CALLNODE
*****************************************************************************}
procedure ti8086callnode.extra_interrupt_code;
begin
emit_none(A_PUSHF,S_W);
emit_reg(A_PUSH,S_W,NR_CS);
end;
procedure ti8086callnode.pop_parasize(pop_size:longint);
var
hreg : tregister;
begin
if (paramanager.use_fixed_stack) then
begin
{ very weird: in this case the callee does a "ret $4" and the }
{ caller immediately a "subl $4,%esp". Possibly this is for }
{ use_fixed_stack code to be able to transparently call }
{ old-style code (JM) }
dec(pop_size,pushedparasize);
if (pop_size < 0) then
current_asmdata.CurrAsmList.concat(taicpu.op_const_reg(A_SUB,S_W,-pop_size,NR_SP));
exit;
end;
{ better than an add on all processors }
if pop_size=2 then
begin
hreg:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
current_asmdata.CurrAsmList.concat(taicpu.op_reg(A_POP,S_W,hreg));
end
{ the pentium has two pipes and pop reg is pairable }
{ but the registers must be different! }
else
if pop_size<>0 then
current_asmdata.CurrAsmList.concat(taicpu.op_const_reg(A_ADD,S_W,pop_size,NR_SP));
end;
begin
ccallnode:=ti8086callnode;
end.