{
Copyright (c) 2002 by Florian Klaempfl
Generic calling convention handling
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.
****************************************************************************
}
{# Parameter passing manager. Used to manage how
parameters are passed to routines.
}
unit paramgr;
{$i fpcdefs.inc}
interface
uses
cclasses,globtype,
cpubase,cgbase,
parabase,
aasmtai,aasmdata,
symconst,symtype,symsym,symdef;
type
{# This class defines some methods to take care of routine
parameters. It should be overriden for each new processor
}
tparamanager = class
{ true if the location in paraloc can be reused as localloc }
function param_use_paraloc(const cgpara:tcgpara):boolean;virtual;
{# Returns true if the return value is actually a parameter
pointer.
}
function ret_in_param(def : tdef;calloption : tproccalloption) : boolean;virtual;
function push_high_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;virtual;
{ Returns true if a parameter is too large to copy and only
the address is pushed
}
function push_addr_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;virtual;abstract;
{ return the size of a push }
function push_size(varspez:tvarspez;def : tdef;calloption : tproccalloption) : longint;
{# Returns a structure giving the information on
the storage of the parameter (which must be
an integer parameter). This is only used when calling
internal routines directly, where all parameters must
be 4-byte values.
In case the location is a register, this register is allocated.
Call freeintparaloc() after the call to free the locations again.
Default implementation: don't do anything at all (in case you don't
use register parameter passing)
@param(list Current assembler list)
@param(nr Parameter number of routine, starting from 1)
}
function get_para_align(calloption : tproccalloption):byte;virtual;
function get_volatile_registers_int(calloption : tproccalloption):tcpuregisterset;virtual;
function get_volatile_registers_fpu(calloption : tproccalloption):tcpuregisterset;virtual;
function get_volatile_registers_flags(calloption : tproccalloption):tcpuregisterset;virtual;
function get_volatile_registers_mm(calloption : tproccalloption):tcpuregisterset;virtual;
procedure getintparaloc(calloption : tproccalloption; nr : longint;var cgpara:TCGPara);virtual;abstract;
{# allocate a parameter location created with create_paraloc_info
@param(list Current assembler list)
@param(loc Parameter location)
}
procedure allocparaloc(list: TAsmList; const cgpara: TCGPara); virtual;
{# free a parameter location allocated with alloccgpara
@param(list Current assembler list)
@param(loc Parameter location)
}
procedure freeparaloc(list: TAsmList; const cgpara: TCGPara); virtual;
{ This is used to populate the location information on all parameters
for the routine as seen in either the caller or the callee. It returns
the size allocated on the stack
}
function create_paraloc_info(p : tabstractprocdef; side: tcallercallee):longint;virtual;abstract;
{ This is used to populate the location information on all parameters
for the routine when it is being inlined. It returns
the size allocated on the stack
}
function create_inline_paraloc_info(p : tabstractprocdef):longint;virtual;
{ This is used to populate the location information on all parameters
for the routine that are passed as varargs. It returns
the size allocated on the stack (including the normal parameters)
}
function create_varargs_paraloc_info(p : tabstractprocdef; varargspara:tvarargsparalist):longint;virtual;abstract;
procedure createtempparaloc(list: TAsmList;calloption : tproccalloption;parasym : tparavarsym;var cgpara:TCGPara);virtual;
procedure duplicateparaloc(list: TAsmList;calloption : tproccalloption;parasym : tparavarsym;var cgpara:TCGPara);
function parseparaloc(parasym : tparavarsym;const s : string) : boolean;virtual;abstract;
function parsefuncretloc(p : tabstractprocdef; const s : string) : boolean;virtual;abstract;
end;
var
paramanager : tparamanager;
implementation
uses
systems,
cgobj,tgobj,cgutils,
defutil,verbose;
{ true if the location in paraloc can be reused as localloc }
function tparamanager.param_use_paraloc(const cgpara:tcgpara):boolean;
begin
result:=false;
end;
{ true if uses a parameter as return value }
function tparamanager.ret_in_param(def : tdef;calloption : tproccalloption) : boolean;
begin
ret_in_param:=((def.typ=arraydef) and not(is_dynamic_array(def))) or
(def.typ=recorddef) or
((def.typ=stringdef) and (tstringdef(def).stringtype in [st_shortstring,st_longstring])) or
((def.typ=procvardef) and (po_methodpointer in tprocvardef(def).procoptions)) or
{ interfaces are also passed by reference to be compatible with delphi and COM }
((def.typ=objectdef) and (is_object(def) or is_interface(def))) or
(def.typ=variantdef) or
((def.typ=setdef) and (tsetdef(def).settype<>smallset));
end;
function tparamanager.push_high_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;
begin
push_high_param:=not(calloption in [pocall_cdecl,pocall_cppdecl]) and
(
is_open_array(def) or
is_open_string(def) or
is_array_of_const(def)
);
end;
{ return the size of a push }
function tparamanager.push_size(varspez:tvarspez;def : tdef;calloption : tproccalloption) : longint;
begin
push_size:=-1;
case varspez of
vs_out,
vs_var :
push_size:=sizeof(aint);
vs_value,
vs_const :
begin
if push_addr_param(varspez,def,calloption) then
push_size:=sizeof(aint)
else
begin
{ special array are normally pushed by addr, only for
cdecl array of const it comes here and the pushsize
is unknown }
if is_array_of_const(def) then
push_size:=0
else
push_size:=def.size;
end;
end;
end;
end;
function tparamanager.get_para_align(calloption : tproccalloption):byte;
begin
result:=std_param_align;
end;
function tparamanager.get_volatile_registers_int(calloption : tproccalloption):tcpuregisterset;
begin
result:=[];
end;
function tparamanager.get_volatile_registers_fpu(calloption : tproccalloption):tcpuregisterset;
begin
result:=[];
end;
function tparamanager.get_volatile_registers_flags(calloption : tproccalloption):tcpuregisterset;
begin
result:=[];
end;
function tparamanager.get_volatile_registers_mm(calloption : tproccalloption):tcpuregisterset;
begin
result:=[];
end;
procedure tparamanager.allocparaloc(list: TAsmList; const cgpara: TCGPara);
var
paraloc : pcgparalocation;
begin
paraloc:=cgpara.location;
while assigned(paraloc) do
begin
case paraloc^.loc of
LOC_REGISTER,
LOC_CREGISTER:
begin
if getsupreg(paraloc^.register)<first_int_imreg then
cg.getcpuregister(list,paraloc^.register);
end;
LOC_FPUREGISTER,
LOC_CFPUREGISTER:
begin
if getsupreg(paraloc^.register)<first_fpu_imreg then
cg.getcpuregister(list,paraloc^.register);
end;
LOC_MMREGISTER,
LOC_CMMREGISTER :
begin
if getsupreg(paraloc^.register)<first_mm_imreg then
cg.getcpuregister(list,paraloc^.register);
end;
end;
paraloc:=paraloc^.next;
end;
end;
procedure tparamanager.freeparaloc(list: TAsmList; const cgpara: TCGPara);
var
paraloc : Pcgparalocation;
href : treference;
begin
paraloc:=cgpara.location;
while assigned(paraloc) do
begin
case paraloc^.loc of
LOC_VOID:
;
LOC_REGISTER,
LOC_CREGISTER:
begin
if getsupreg(paraloc^.register)<first_int_imreg then
cg.ungetcpuregister(list,paraloc^.register);
end;
LOC_FPUREGISTER,
LOC_CFPUREGISTER:
begin
if getsupreg(paraloc^.register)<first_fpu_imreg then
cg.ungetcpuregister(list,paraloc^.register);
end;
LOC_MMREGISTER,
LOC_CMMREGISTER :
begin
if getsupreg(paraloc^.register)<first_mm_imreg then
cg.ungetcpuregister(list,paraloc^.register);
end;
LOC_REFERENCE,
LOC_CREFERENCE :
begin
if use_fixed_stack then
begin
{ don't use reference_reset_base, because that will depend on cgobj }
fillchar(href,sizeof(href),0);
href.base:=paraloc^.reference.index;
href.offset:=paraloc^.reference.offset;
tg.ungettemp(list,href);
end;
end;
else
internalerror(2004110212);
end;
paraloc:=paraloc^.next;
end;
end;
procedure tparamanager.createtempparaloc(list: TAsmList;calloption : tproccalloption;parasym : tparavarsym;var cgpara:TCGPara);
var
href : treference;
len : aint;
paraloc,
newparaloc : pcgparalocation;
begin
cgpara.reset;
cgpara.size:=parasym.paraloc[callerside].size;
cgpara.intsize:=parasym.paraloc[callerside].intsize;
cgpara.alignment:=parasym.paraloc[callerside].alignment;
{$ifdef powerpc}
cgpara.composite:=parasym.paraloc[callerside].composite;
{$endif powerpc}
paraloc:=parasym.paraloc[callerside].location;
while assigned(paraloc) do
begin
if paraloc^.size=OS_NO then
len:=push_size(parasym.varspez,parasym.vardef,calloption)
else
len:=tcgsize2size[paraloc^.size];
newparaloc:=cgpara.add_location;
newparaloc^.size:=paraloc^.size;
{ $warning maybe release this optimization for all targets? }
{ released for all CPUs:
i386 isn't affected anyways because it uses the stack to push parameters
on arm it reduces executable size of the compiler by 2.1 per cent (FK) }
{ Does it fit a register? }
if (len<=sizeof(aint)) and
(cgpara.size in [OS_8,OS_16,OS_32,OS_64,OS_128,OS_S8,OS_S16,OS_S32,OS_S64,OS_S128]) then
newparaloc^.loc:=LOC_REGISTER
else
newparaloc^.loc:=paraloc^.loc;
case newparaloc^.loc of
LOC_REGISTER :
newparaloc^.register:=cg.getintregister(list,paraloc^.size);
LOC_FPUREGISTER :
newparaloc^.register:=cg.getfpuregister(list,paraloc^.size);
LOC_MMREGISTER :
newparaloc^.register:=cg.getmmregister(list,paraloc^.size);
LOC_REFERENCE :
begin
tg.gettemp(list,len,tt_persistent,href);
newparaloc^.reference.index:=href.base;
newparaloc^.reference.offset:=href.offset;
end;
end;
paraloc:=paraloc^.next;
end;
end;
procedure tparamanager.duplicateparaloc(list: TAsmList;calloption : tproccalloption;parasym : tparavarsym;var cgpara:TCGPara);
var
paraloc,
newparaloc : pcgparalocation;
begin
cgpara.reset;
cgpara.size:=parasym.paraloc[callerside].size;
cgpara.intsize:=parasym.paraloc[callerside].intsize;
cgpara.alignment:=parasym.paraloc[callerside].alignment;
{$ifdef powerpc}
cgpara.composite:=parasym.paraloc[callerside].composite;
{$endif powerpc}
paraloc:=parasym.paraloc[callerside].location;
while assigned(paraloc) do
begin
newparaloc:=cgpara.add_location;
move(paraloc^,newparaloc^,sizeof(newparaloc^));
newparaloc^.next:=nil;
paraloc:=paraloc^.next;
end;
end;
function tparamanager.create_inline_paraloc_info(p : tabstractprocdef):longint;
begin
{ We need to return the size allocated }
create_paraloc_info(p,callerside);
result:=create_paraloc_info(p,calleeside);
end;
initialization
;
finalization
paramanager.free;
end.
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