fpc/compiler/i8086/n8086ld.pas
2014-03-30 17:50:35 +00:00

92 lines
3.1 KiB
ObjectPascal

{
Copyright (c) 2002-2014 by Florian Klaempfl
Generate i8086 assembler for load 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 n8086ld;
{$i fpcdefs.inc}
interface
uses
globtype,
symsym,symtype,
node,ncgld;
type
ti8086loadnode = class(tcgloadnode)
procedure generate_nested_access(vs: tsym); override;
procedure generate_absaddr_access(vs: tabsolutevarsym); override;
end;
implementation
uses
globals,aasmdata,
symcpu,
nld,
cgbase,cgobj,
cpubase,cpuinfo;
{*****************************************************************************
TI8086LOADNODE
*****************************************************************************}
procedure ti8086loadnode.generate_nested_access(vs: tsym);
begin
inherited;
{ the parentfp pointer is always a near pointer (this is turbo pascal
compatible) regardless of memory model, so we need to set the segment
manually.
todo: once the far data memory models are fully implemented, the
parentfp type should be changed to a near 'ss' pointer in all memory
models and then this code can be removed. But this can only happen
after:
1) all calls to a_loadaddr_ref_reg go through the high level code
generator
2) a_loadaddr_ref_reg in the low level code generator stops using
the presence of a segment in the source reference to determine the
destination reg size
3) make_simple_ref is updated to remove unnecessary segment prefixes
4) hlcg.reference_reset_base is updated to set the segment on near_ss
pointers }
if (left.nodetype=loadparentfpn) and
(current_settings.x86memorymodel in x86_far_data_models) then
location.reference.segment:=NR_SS;
end;
procedure ti8086loadnode.generate_absaddr_access(vs: tabsolutevarsym);
begin
if tcpuabsolutevarsym(symtableentry).absseg then
begin
location.reference.segment:=cg.getintregister(current_asmdata.CurrAsmList,OS_16);
cg.a_load_const_reg(current_asmdata.CurrAsmList,OS_16,aint(tcpuabsolutevarsym(symtableentry).addrsegment),location.reference.segment);
end;
inherited;
end;
begin
cloadnode:=ti8086loadnode;
end.