{
Copyright (c) 2003 by Florian Klaempfl
ARM specific calling conventions
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.
****************************************************************************
}
{ ARM specific calling conventions are handled by this unit
}
unit cpupara;
{$i fpcdefs.inc}
interface
uses
globtype,globals,
aasmtai,aasmdata,
cpuinfo,cpubase,cgbase,
symconst,symbase,symtype,symdef,parabase,paramgr;
type
tarmparamanager = class(tparamanager)
function get_volatile_registers_int(calloption : tproccalloption):tcpuregisterset;override;
function get_volatile_registers_fpu(calloption : tproccalloption):tcpuregisterset;override;
function push_addr_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;override;
function ret_in_param(def : tdef;calloption : tproccalloption) : boolean;override;
procedure getintparaloc(calloption : tproccalloption; nr : longint;var cgpara:TCGPara);override;
function create_paraloc_info(p : tabstractprocdef; side: tcallercallee):longint;override;
function create_varargs_paraloc_info(p : tabstractprocdef; varargspara:tvarargsparalist):longint;override;
private
procedure init_values(var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword);
function create_paraloc_info_intern(p : tabstractprocdef; side: tcallercallee; paras: tparalist;
var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword):longint;
end;
implementation
uses
verbose,systems,
rgobj,
defutil,symsym,
cgutils;
function tarmparamanager.get_volatile_registers_int(calloption : tproccalloption):tcpuregisterset;
begin
result:=VOLATILE_INTREGISTERS;
end;
function tarmparamanager.get_volatile_registers_fpu(calloption : tproccalloption):tcpuregisterset;
begin
result:=VOLATILE_FPUREGISTERS;
end;
procedure tarmparamanager.getintparaloc(calloption : tproccalloption; nr : longint;var cgpara:TCGPara);
var
paraloc : pcgparalocation;
begin
if nr<1 then
internalerror(2002070801);
cgpara.reset;
cgpara.size:=OS_INT;
cgpara.intsize:=tcgsize2size[OS_INT];
cgpara.alignment:=std_param_align;
paraloc:=cgpara.add_location;
with paraloc^ do
begin
size:=OS_INT;
{ the four first parameters are passed into registers }
if nr<=4 then
begin
loc:=LOC_REGISTER;
register:=newreg(R_INTREGISTER,RS_R0+nr-1,R_SUBWHOLE);
end
else
begin
{ the other parameters are passed on the stack }
loc:=LOC_REFERENCE;
reference.index:=NR_STACK_POINTER_REG;
reference.offset:=(nr-5)*4;
end;
end;
end;
function getparaloc(calloption : tproccalloption; p : tdef) : tcgloc;
begin
{ Later, the LOC_REFERENCE is in most cases changed into LOC_REGISTER
if push_addr_param for the def is true
}
case p.typ of
orddef:
getparaloc:=LOC_REGISTER;
floatdef:
if (calloption in [pocall_cdecl,pocall_cppdecl,pocall_softfloat]) or (cs_fp_emulation in current_settings.moduleswitches) then
getparaloc:=LOC_REGISTER
else
getparaloc:=LOC_FPUREGISTER;
enumdef:
getparaloc:=LOC_REGISTER;
pointerdef:
getparaloc:=LOC_REGISTER;
formaldef:
getparaloc:=LOC_REGISTER;
classrefdef:
getparaloc:=LOC_REGISTER;
recorddef:
getparaloc:=LOC_REGISTER;
objectdef:
getparaloc:=LOC_REGISTER;
stringdef:
if is_shortstring(p) or is_longstring(p) then
getparaloc:=LOC_REFERENCE
else
getparaloc:=LOC_REGISTER;
procvardef:
getparaloc:=LOC_REGISTER;
filedef:
getparaloc:=LOC_REGISTER;
arraydef:
getparaloc:=LOC_REFERENCE;
setdef:
if is_smallset(p) then
getparaloc:=LOC_REGISTER
else
getparaloc:=LOC_REFERENCE;
variantdef:
getparaloc:=LOC_REGISTER;
{ avoid problems with errornous definitions }
errordef:
getparaloc:=LOC_REGISTER;
else
internalerror(2002071001);
end;
end;
function tarmparamanager.push_addr_param(varspez:tvarspez;def : tdef;calloption : tproccalloption) : boolean;
begin
result:=false;
if varspez in [vs_var,vs_out] then
begin
result:=true;
exit;
end;
case def.typ of
objectdef,
recorddef:
result:=(varspez=vs_const) or (def.size=0);
variantdef,
formaldef:
result:=true;
arraydef:
result:=(tarraydef(def).highrange>=tarraydef(def).lowrange) or
is_open_array(def) or
is_array_of_const(def) or
is_array_constructor(def);
setdef :
result:=(tsetdef(def).settype<>smallset);
stringdef :
result:=tstringdef(def).stringtype in [st_shortstring,st_longstring];
end;
end;
function tarmparamanager.ret_in_param(def : tdef;calloption : tproccalloption) : boolean;
begin
case def.typ of
recorddef:
{ this is how gcc 4.0.4 on linux seems to do it, it doesn't look like being
ARM ABI standard compliant
}
result:=not((trecorddef(def).symtable.SymList.count=1) and
not(ret_in_param(tabstractvarsym(trecorddef(def).symtable.SymList[0]).vardef,calloption)));
{
objectdef
arraydef:
result:=not(def.size in [1,2,4]);
}
else
result:=inherited ret_in_param(def,calloption);
end;
end;
procedure tarmparamanager.init_values(var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword);
begin
curintreg:=RS_R0;
curfloatreg:=RS_F0;
curmmreg:=RS_D0;
cur_stack_offset:=0;
end;
function tarmparamanager.create_paraloc_info_intern(p : tabstractprocdef; side: tcallercallee; paras: tparalist;
var curintreg, curfloatreg, curmmreg: tsuperregister; var cur_stack_offset: aword):longint;
var
nextintreg,nextfloatreg,nextmmreg : tsuperregister;
paradef : tdef;
paraloc : pcgparalocation;
stack_offset : aword;
hp : tparavarsym;
loc : tcgloc;
paracgsize : tcgsize;
paralen : longint;
i : integer;
procedure assignintreg;
begin
if nextintreg<=RS_R3 then
begin
paraloc^.loc:=LOC_REGISTER;
paraloc^.register:=newreg(R_INTREGISTER,nextintreg,R_SUBWHOLE);
inc(nextintreg);
end
else
begin
paraloc^.loc:=LOC_REFERENCE;
paraloc^.reference.index:=NR_STACK_POINTER_REG;
paraloc^.reference.offset:=stack_offset;
inc(stack_offset,4);
end;
end;
begin
result:=0;
nextintreg:=curintreg;
nextfloatreg:=curfloatreg;
nextmmreg:=curmmreg;
stack_offset:=cur_stack_offset;
for i:=0 to paras.count-1 do
begin
hp:=tparavarsym(paras[i]);
paradef:=hp.vardef;
hp.paraloc[side].reset;
{ currently only support C-style array of const,
there should be no location assigned to the vararg array itself }
if (p.proccalloption in [pocall_cdecl,pocall_cppdecl]) and
is_array_of_const(paradef) then
begin
paraloc:=hp.paraloc[side].add_location;
{ hack: the paraloc must be valid, but is not actually used }
paraloc^.loc:=LOC_REGISTER;
paraloc^.register:=NR_R0;
paraloc^.size:=OS_ADDR;
break;
end;
if (hp.varspez in [vs_var,vs_out]) or
push_addr_param(hp.varspez,paradef,p.proccalloption) or
is_open_array(paradef) or
is_array_of_const(paradef) then
begin
paradef:=voidpointertype;
loc:=LOC_REGISTER;
paracgsize := OS_ADDR;
paralen := tcgsize2size[OS_ADDR];
end
else
begin
if not is_special_array(paradef) then
paralen := paradef.size
else
paralen := tcgsize2size[def_cgsize(paradef)];
loc := getparaloc(p.proccalloption,paradef);
if (paradef.typ in [objectdef,arraydef,recorddef]) and
not is_special_array(paradef) and
(hp.varspez in [vs_value,vs_const]) then
paracgsize := int_cgsize(paralen)
else
begin
paracgsize:=def_cgsize(paradef);
{ for things like formaldef }
if (paracgsize=OS_NO) then
begin
paracgsize:=OS_ADDR;
paralen := tcgsize2size[OS_ADDR];
end;
end
end;
hp.paraloc[side].size:=paracgsize;
hp.paraloc[side].Alignment:=std_param_align;
hp.paraloc[side].intsize:=paralen;
{$ifdef EXTDEBUG}
if paralen=0 then
internalerror(200410311);
{$endif EXTDEBUG}
while paralen>0 do
begin
paraloc:=hp.paraloc[side].add_location;
if (loc=LOC_REGISTER) and (paracgsize in [OS_F32,OS_F64,OS_F80]) then
case paracgsize of
OS_F32:
paraloc^.size:=OS_32;
OS_F64:
paraloc^.size:=OS_32;
else
internalerror(2005082901);
end
else if (paracgsize in [OS_NO,OS_64,OS_S64]) then
paraloc^.size := OS_32
else
paraloc^.size:=paracgsize;
case loc of
LOC_REGISTER:
begin
{ this is not abi compliant }
if nextintreg<=RS_R3 then
begin
paraloc^.loc:=LOC_REGISTER;
paraloc^.register:=newreg(R_INTREGISTER,nextintreg,R_SUBWHOLE);
inc(nextintreg);
end
else
begin
{ LOC_REFERENCE covers always the overleft }
paraloc^.loc:=LOC_REFERENCE;
paraloc^.size:=int_cgsize(paralen);
if (side=callerside) then
paraloc^.reference.index:=NR_STACK_POINTER_REG;
paraloc^.reference.offset:=stack_offset;
inc(stack_offset,align(paralen,4));
paralen:=0;
end;
end;
LOC_FPUREGISTER:
begin
if nextfloatreg<=RS_F3 then
begin
paraloc^.loc:=LOC_FPUREGISTER;
paraloc^.register:=newreg(R_FPUREGISTER,nextfloatreg,R_SUBWHOLE);
inc(nextfloatreg);
end
else
begin
paraloc^.loc:=LOC_REFERENCE;
paraloc^.reference.index:=NR_STACK_POINTER_REG;
paraloc^.reference.offset:=stack_offset;
case paraloc^.size of
OS_F32:
inc(stack_offset,4);
OS_F64:
inc(stack_offset,8);
OS_F80:
inc(stack_offset,10);
OS_F128:
inc(stack_offset,16);
else
internalerror(200403201);
end;
end;
end;
LOC_REFERENCE:
begin
paraloc^.size:=OS_ADDR;
if push_addr_param(hp.varspez,paradef,p.proccalloption) or
is_open_array(paradef) or
is_array_of_const(paradef) then
assignintreg
else
begin
paraloc^.loc:=LOC_REFERENCE;
paraloc^.reference.index:=NR_STACK_POINTER_REG;
paraloc^.reference.offset:=stack_offset;
inc(stack_offset,hp.vardef.size);
end;
end;
else
internalerror(2002071002);
end;
if side=calleeside then
begin
if paraloc^.loc=LOC_REFERENCE then
begin
paraloc^.reference.index:=NR_FRAME_POINTER_REG;
inc(paraloc^.reference.offset,4);
end;
end;
dec(paralen,tcgsize2size[paraloc^.size]);
end;
end;
curintreg:=nextintreg;
curfloatreg:=nextfloatreg;
curmmreg:=nextmmreg;
cur_stack_offset:=stack_offset;
result:=cur_stack_offset;
end;
function tarmparamanager.create_paraloc_info(p : tabstractprocdef; side: tcallercallee):longint;
var
cur_stack_offset: aword;
curintreg, curfloatreg, curmmreg: tsuperregister;
retcgsize : tcgsize;
begin
init_values(curintreg,curfloatreg,curmmreg,cur_stack_offset);
result:=create_paraloc_info_intern(p,side,p.paras,curintreg,curfloatreg,curmmreg,cur_stack_offset);
{ Constructors return self instead of a boolean }
if (p.proctypeoption=potype_constructor) then
retcgsize:=OS_ADDR
else
retcgsize:=def_cgsize(p.returndef);
location_reset(p.funcretloc[side],LOC_INVALID,OS_NO);
p.funcretloc[side].size:=retcgsize;
{ void has no location }
if is_void(p.returndef) then
begin
location_reset(p.funcretloc[side],LOC_VOID,OS_NO);
exit;
end;
{ Return is passed as var parameter }
if ret_in_param(p.returndef,p.proccalloption) then
begin
p.funcretloc[side].loc:=LOC_REFERENCE;
p.funcretloc[side].size:=retcgsize;
exit;
end;
{ Return in FPU register? }
if p.returndef.typ=floatdef then
begin
if (p.proccalloption in [pocall_softfloat]) or (cs_fp_emulation in current_settings.moduleswitches) then
begin
case retcgsize of
OS_64,
OS_F64:
begin
{ low }
p.funcretloc[side].loc:=LOC_REGISTER;
p.funcretloc[side].register64.reglo:=NR_FUNCTION_RESULT64_LOW_REG;
p.funcretloc[side].register64.reghi:=NR_FUNCTION_RESULT64_HIGH_REG;
p.funcretloc[side].size:=OS_64;
end;
OS_32,
OS_F32:
begin
p.funcretloc[side].loc:=LOC_REGISTER;
p.funcretloc[side].register:=NR_FUNCTION_RETURN_REG;
p.funcretloc[side].size:=OS_32;
end;
else
internalerror(2005082603);
end;
end
else
begin
p.funcretloc[side].loc:=LOC_FPUREGISTER;
p.funcretloc[side].register:=NR_FPU_RESULT_REG;
end;
end
{ Return in register }
else
begin
if retcgsize in [OS_64,OS_S64] then
begin
{ low }
p.funcretloc[side].loc:=LOC_REGISTER;
p.funcretloc[side].register64.reglo:=NR_FUNCTION_RESULT64_LOW_REG;
p.funcretloc[side].register64.reghi:=NR_FUNCTION_RESULT64_HIGH_REG;
end
else
begin
p.funcretloc[side].loc:=LOC_REGISTER;
p.funcretloc[side].register:=NR_FUNCTION_RETURN_REG;
end;
end;
end;
function tarmparamanager.create_varargs_paraloc_info(p : tabstractprocdef; varargspara:tvarargsparalist):longint;
var
cur_stack_offset: aword;
curintreg, curfloatreg, curmmreg: tsuperregister;
begin
init_values(curintreg,curfloatreg,curmmreg,cur_stack_offset);
result:=create_paraloc_info_intern(p,callerside,p.paras,curintreg,curfloatreg,curmmreg,cur_stack_offset);
if (p.proccalloption in [pocall_cdecl,pocall_cppdecl]) then
{ just continue loading the parameters in the registers }
result:=create_paraloc_info_intern(p,callerside,varargspara,curintreg,curfloatreg,curmmreg,cur_stack_offset)
else
internalerror(200410231);
end;
begin
paramanager:=tarmparamanager.create;
end.
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