{ Copyright (c) 1998-2002 by Florian Klaempfl Generate assembler for nodes that handle loads and assignments which are the same for all (most) processors 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 ncgld; {$i fpcdefs.inc} interface uses node,nld,cgutils; type tcgloadnode = class(tloadnode) procedure pass_generate_code;override; procedure generate_picvaraccess;virtual; procedure changereflocation(const ref: treference); end; tcgassignmentnode = class(tassignmentnode) procedure pass_generate_code;override; end; tcgarrayconstructornode = class(tarrayconstructornode) procedure pass_generate_code;override; end; tcgrttinode = class(trttinode) procedure pass_generate_code;override; end; implementation uses cutils, systems, verbose,globtype,globals,constexp, nutils, symconst,symtype,symdef,symsym,defutil,paramgr, ncnv,ncon,nmem,nbas,ncgrtti, aasmbase,aasmtai,aasmdata,aasmcpu, cgbase,pass_2, procinfo, cpubase,parabase, tgobj,ncgutil, cgobj, ncgbas,ncgflw; {***************************************************************************** SSA (for memory temps) support *****************************************************************************} type preplacerefrec = ^treplacerefrec; treplacerefrec = record old, new: preference; ressym: tsym; end; function doreplaceref(var n: tnode; para: pointer): foreachnoderesult; var rr: preplacerefrec absolute para; begin result := fen_false; case n.nodetype of loadn: begin { regular variable } if (tabstractvarsym(tloadnode(n).symtableentry).varoptions * [vo_is_dll_var, vo_is_thread_var] = []) and not assigned(tloadnode(n).left) and { not function result, or no exit in function } (((tloadnode(n).symtableentry <> rr^.ressym) and not(vo_is_funcret in tabstractvarsym(tloadnode(n).symtableentry).varoptions)) or not(fc_exit in flowcontrol)) and { stored in memory... } (tabstractnormalvarsym(tloadnode(n).symtableentry).localloc.loc in [LOC_REFERENCE]) and { ... at the place we are looking for } references_equal(tabstractnormalvarsym(tloadnode(n).symtableentry).localloc.reference,rr^.old^) then begin { relocate variable } tcgloadnode(n).changereflocation(rr^.new^); result := fen_norecurse_true; end; end; temprefn: begin if (ttemprefnode(n).tempinfo^.valid) and { memory temp... } (ttemprefnode(n).tempinfo^.location.loc in [LOC_REFERENCE]) and { ... at the place we are looking for } references_equal(ttemprefnode(n).tempinfo^.location.reference,rr^.old^) then begin { relocate the temp } tcgtemprefnode(n).changelocation(rr^.new^); result := fen_norecurse_true; end; end; { optimize the searching a bit } derefn,addrn, calln,inlinen,casen, addn,subn,muln, andn,orn,xorn, ltn,lten,gtn,gten,equaln,unequaln, slashn,divn,shrn,shln,notn, inn, asn,isn: result := fen_norecurse_false; end; end; function maybechangetemp(list: TAsmList; var n: tnode; const newref: treference): boolean; var rr: treplacerefrec; begin result := false; { only do for -O2 or higher (breaks debugging since } { variables move to different memory locations) } if not(cs_opt_level2 in current_settings.optimizerswitches) or { must be a copy to a memory location ... } (n.location.loc <> LOC_REFERENCE) or { not inside a control flow statement and no goto's in sight } ([fc_inflowcontrol,fc_gotolabel] * flowcontrol <> []) or { source and destination are temps (= not global variables) } not tg.istemp(n.location.reference) or not tg.istemp(newref) or { and both point to the start of a temp, and the source is a } { non-persistent temp (otherwise we need some kind of copy- } { on-write support in case later on both are still used) } (tg.gettypeoftemp(newref) <> tt_normal) or not (tg.gettypeoftemp(n.location.reference) in [tt_normal,tt_persistent]) or { and both have the same size } (tg.sizeoftemp(current_asmdata.CurrAsmList,newref) <> tg.sizeoftemp(current_asmdata.CurrAsmList,n.location.reference)) then exit; { find the source of the old reference (loadnode or tempnode) } { and replace it with the new reference } rr.old := @n.location.reference; rr.new := @newref; rr.ressym := nil; if (current_procinfo.procdef.funcretloc[calleeside].loc<>LOC_VOID) and assigned(current_procinfo.procdef.funcretsym) and (tabstractvarsym(current_procinfo.procdef.funcretsym).refs <> 0) then if (current_procinfo.procdef.proctypeoption=potype_constructor) then rr.ressym:=tsym(current_procinfo.procdef.parast.Find('self')) else rr.ressym:=current_procinfo.procdef.funcretsym; { if source not found, don't do anything } if not foreachnodestatic(n,@doreplaceref,@rr) then exit; n.location.reference := newref; result:=true; end; {***************************************************************************** SecondLoad *****************************************************************************} procedure tcgloadnode.generate_picvaraccess; begin {$ifndef sparc} location.reference.base:=current_procinfo.got; location.reference.symbol:=current_asmdata.RefAsmSymbol(tstaticvarsym(symtableentry).mangledname+'@GOT'); {$endif sparc} end; procedure tcgloadnode.changereflocation(const ref: treference); var oldtemptype: ttemptype; begin if (location.loc<>LOC_REFERENCE) then internalerror(2007020812); if not tg.istemp(location.reference) then internalerror(2007020813); oldtemptype:=tg.gettypeoftemp(location.reference); if (oldtemptype = tt_persistent) then tg.ChangeTempType(current_asmdata.CurrAsmList,location.reference,tt_normal); tg.ungettemp(current_asmdata.CurrAsmList,location.reference); location.reference:=ref; tg.ChangeTempType(current_asmdata.CurrAsmList,location.reference,oldtemptype); tabstractnormalvarsym(symtableentry).localloc:=location; end; procedure tcgloadnode.pass_generate_code; var hregister : tregister; vs : tabstractnormalvarsym; gvs : tstaticvarsym; pd : tprocdef; href : treference; newsize : tcgsize; endrelocatelab, norelocatelab : tasmlabel; paraloc1 : tcgpara; begin { we don't know the size of all arrays } newsize:=def_cgsize(resultdef); location_reset(location,LOC_REFERENCE,newsize); case symtableentry.typ of absolutevarsym : begin { this is only for toasm and toaddr } case tabsolutevarsym(symtableentry).abstyp of toaddr : begin {$ifdef i386} if tabsolutevarsym(symtableentry).absseg then location.reference.segment:=NR_FS; {$endif i386} location.reference.offset:=tabsolutevarsym(symtableentry).addroffset; end; toasm : location.reference.symbol:=current_asmdata.RefAsmSymbol(tabsolutevarsym(symtableentry).mangledname); else internalerror(200310283); end; end; constsym: begin if tconstsym(symtableentry).consttyp=constresourcestring then begin location_reset(location,LOC_CREFERENCE,OS_ADDR); location.reference.symbol:=current_asmdata.RefAsmSymbol(make_mangledname('RESSTR',symtableentry.owner,symtableentry.name)); { Resourcestring layout: TResourceStringRecord = Packed Record Name, CurrentValue, DefaultValue : AnsiString; HashValue : LongWord; end; } location.reference.offset:=sizeof(aint); end else internalerror(22798); end; staticvarsym : begin gvs:=tstaticvarsym(symtableentry); if ([vo_is_dll_var,vo_is_external] * gvs.varoptions <> []) then begin location.reference.base := cg.g_indirect_sym_load(current_asmdata.CurrAsmList,tstaticvarsym(symtableentry).mangledname); if (location.reference.base <> NR_NO) then exit; end; if (vo_is_dll_var in gvs.varoptions) then { DLL variable } begin hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); location.reference.symbol:=current_asmdata.RefAsmSymbol(tstaticvarsym(symtableentry).mangledname); cg.a_load_ref_reg(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,location.reference,hregister); reference_reset_base(location.reference,hregister,0); end { Thread variable } else if (vo_is_thread_var in gvs.varoptions) and not(tf_section_threadvars in target_info.flags) then begin if (tf_section_threadvars in target_info.flags) then begin if gvs.localloc.loc=LOC_INVALID then reference_reset_symbol(location.reference,current_asmdata.RefAsmSymbol(gvs.mangledname),0) else location:=gvs.localloc; {$ifdef i386} case target_info.system of system_i386_linux: location.reference.segment:=NR_GS; system_i386_win32: location.reference.segment:=NR_FS; end; {$endif i386} end else begin { Thread var loading is optimized to first check if a relocate function is available. When the function is available it is called to retrieve the address. Otherwise the address is loaded with the symbol The code needs to be in the order to first handle the call and then the address load to be sure that the register that is used for returning is the same (PFV) } current_asmdata.getjumplabel(norelocatelab); current_asmdata.getjumplabel(endrelocatelab); { make sure hregister can't allocate the register necessary for the parameter } paraloc1.init; paramanager.getintparaloc(pocall_default,1,paraloc1); hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); reference_reset_symbol(href,current_asmdata.RefAsmSymbol('FPC_THREADVAR_RELOCATE'),0); cg.a_load_ref_reg(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,href,hregister); cg.a_cmp_const_reg_label(current_asmdata.CurrAsmList,OS_ADDR,OC_EQ,0,hregister,norelocatelab); { don't save the allocated register else the result will be destroyed later } reference_reset_symbol(href,current_asmdata.RefAsmSymbol(tstaticvarsym(symtableentry).mangledname),0); paramanager.allocparaloc(current_asmdata.CurrAsmList,paraloc1); cg.a_param_ref(current_asmdata.CurrAsmList,OS_32,href,paraloc1); paramanager.freeparaloc(current_asmdata.CurrAsmList,paraloc1); paraloc1.done; cg.allocallcpuregisters(current_asmdata.CurrAsmList); cg.a_call_reg(current_asmdata.CurrAsmList,hregister); cg.deallocallcpuregisters(current_asmdata.CurrAsmList); cg.getcpuregister(current_asmdata.CurrAsmList,NR_FUNCTION_RESULT_REG); cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_FUNCTION_RESULT_REG); hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); cg.a_load_reg_reg(current_asmdata.CurrAsmList,OS_INT,OS_ADDR,NR_FUNCTION_RESULT_REG,hregister); cg.a_jmp_always(current_asmdata.CurrAsmList,endrelocatelab); cg.a_label(current_asmdata.CurrAsmList,norelocatelab); { no relocation needed, load the address of the variable only, the layout of a threadvar is (4 bytes pointer): 0 - Threadvar index 4 - Threadvar value in single threading } reference_reset_symbol(href,current_asmdata.RefAsmSymbol(tstaticvarsym(symtableentry).mangledname),sizeof(aint)); cg.a_loadaddr_ref_reg(current_asmdata.CurrAsmList,href,hregister); cg.a_label(current_asmdata.CurrAsmList,endrelocatelab); location.reference.base:=hregister; end; end { Normal (or external) variable } else begin if gvs.localloc.loc=LOC_INVALID then reference_reset_symbol(location.reference,current_asmdata.RefAsmSymbol(gvs.mangledname),0) else location:=gvs.localloc; end; { make const a LOC_CREFERENCE } if (gvs.varspez=vs_const) and (location.loc=LOC_REFERENCE) then location.loc:=LOC_CREFERENCE; end; paravarsym, localvarsym : begin vs:=tabstractnormalvarsym(symtableentry); { Nested variable } if assigned(left) then begin secondpass(left); if left.location.loc<>LOC_REGISTER then internalerror(200309286); if vs.localloc.loc<>LOC_REFERENCE then internalerror(200409241); reference_reset_base(location.reference,left.location.register,vs.localloc.reference.offset); end else location:=vs.localloc; { handle call by reference variables when they are not alreayd copied to local copies. Also ignore the reference when we need to load the self pointer for objects } if is_addr_param_load then begin if (location.loc in [LOC_CREGISTER,LOC_REGISTER]) then hregister:=location.register else begin hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); { we need to load only an address } location.size:=OS_ADDR; cg.a_load_loc_reg(current_asmdata.CurrAsmList,location.size,location,hregister); end; location_reset(location,LOC_REFERENCE,newsize); location.reference.base:=hregister; end; { make const a LOC_CREFERENCE } if (vs.varspez=vs_const) and (location.loc=LOC_REFERENCE) then location.loc:=LOC_CREFERENCE; end; procsym: begin if not assigned(procdef) then internalerror(200312011); if assigned(left) then begin if (sizeof(aint) = 4) then location_reset(location,LOC_CREFERENCE,OS_64) else if (sizeof(aint) = 8) then location_reset(location,LOC_CREFERENCE,OS_128) else internalerror(20020520); tg.GetTemp(current_asmdata.CurrAsmList,2*sizeof(aint),tt_normal,location.reference); secondpass(left); { load class instance address } if left.location.loc=LOC_CONSTANT then location_force_reg(current_asmdata.CurrAsmList,left.location,OS_ADDR,false); case left.location.loc of LOC_CREGISTER, LOC_REGISTER: begin { this is not possible for objects } if is_object(left.resultdef) then internalerror(200304234); hregister:=left.location.register; end; LOC_CREFERENCE, LOC_REFERENCE: begin hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); if is_class_or_interface(left.resultdef) then cg.a_load_ref_reg(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,left.location.reference,hregister) else cg.a_loadaddr_ref_reg(current_asmdata.CurrAsmList,left.location.reference,hregister); location_freetemp(current_asmdata.CurrAsmList,left.location); end; else internalerror(200610311); end; { store the class instance address } href:=location.reference; inc(href.offset,sizeof(aint)); cg.a_load_reg_ref(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,hregister,href); { virtual method ? } if (po_virtualmethod in procdef.procoptions) and not(nf_inherited in flags) then begin { load vmt pointer } reference_reset_base(href,hregister,0); hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); cg.a_load_ref_reg(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,href,hregister); { load method address } reference_reset_base(href,hregister,procdef._class.vmtmethodoffset(procdef.extnumber)); hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); cg.a_load_ref_reg(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,href,hregister); { ... and store it } cg.a_load_reg_ref(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,hregister,location.reference); end else begin { load address of the function } reference_reset_symbol(href,current_asmdata.RefAsmSymbol(procdef.mangledname),0); hregister:=cg.getaddressregister(current_asmdata.CurrAsmList); cg.a_loadaddr_ref_reg(current_asmdata.CurrAsmList,href,hregister); cg.a_load_reg_ref(current_asmdata.CurrAsmList,OS_ADDR,OS_ADDR,hregister,location.reference); end; end else begin pd:=tprocdef(tprocsym(symtableentry).ProcdefList[0]); if (po_external in pd.procoptions) then location.reference.base := cg.g_indirect_sym_load(current_asmdata.CurrAsmList,pd.mangledname); {!!!!! Be aware, work on virtual methods too } if (location.reference.base = NR_NO) then location.reference.symbol:=current_asmdata.RefAsmSymbol(procdef.mangledname); end; end; labelsym : location.reference.symbol:=tcglabelnode((tlabelsym(symtableentry).code)).getasmlabel; else internalerror(200510032); end; end; {***************************************************************************** SecondAssignment *****************************************************************************} procedure tcgassignmentnode.pass_generate_code; var otlabel,hlabel,oflabel : tasmlabel; href : treference; releaseright : boolean; len : aint; r:Tregister; begin location_reset(location,LOC_VOID,OS_NO); otlabel:=current_procinfo.CurrTrueLabel; oflabel:=current_procinfo.CurrFalseLabel; current_asmdata.getjumplabel(current_procinfo.CurrTrueLabel); current_asmdata.getjumplabel(current_procinfo.CurrFalseLabel); { in most cases we can process first the right node which contains the most complex code. Exceptions for this are: - result is in flags, loading left will then destroy the flags - result is a jump, loading left must be already done before the jump is made - result need reference count, when left points to a value used in right then decreasing the refcnt on left can possibly release the memory before right increased the refcnt, result is that an empty value is assigned - calln, call destroys most registers and is therefor 'complex' But not when the result is in the flags, then loading the left node afterwards can destroy the flags. } if not(right.expectloc in [LOC_FLAGS,LOC_JUMP]) and ((right.nodetype=calln) or (right.resultdef.needs_inittable) or (right.registersint>=left.registersint)) then begin secondpass(right); { increment source reference counter, this is useless for string constants} if (right.resultdef.needs_inittable) and (right.nodetype<>stringconstn) then begin location_force_mem(current_asmdata.CurrAsmList,right.location); location_get_data_ref(current_asmdata.CurrAsmList,right.location,href,false); cg.g_incrrefcount(current_asmdata.CurrAsmList,right.resultdef,href); end; if codegenerror then exit; { left can't be never a 64 bit LOC_REGISTER, so the 3. arg } { can be false } secondpass(left); { decrement destination reference counter } if (left.resultdef.needs_inittable) then begin location_get_data_ref(current_asmdata.CurrAsmList,left.location,href,false); cg.g_decrrefcount(current_asmdata.CurrAsmList,left.resultdef,href); end; if codegenerror then exit; end else begin { calculate left sides } secondpass(left); { decrement destination reference counter } if (left.resultdef.needs_inittable) then begin location_get_data_ref(current_asmdata.CurrAsmList,left.location,href,false); cg.g_decrrefcount(current_asmdata.CurrAsmList,left.resultdef,href); end; if codegenerror then exit; { left can't be never a 64 bit LOC_REGISTER, so the 3. arg } { can be false } secondpass(right); { increment source reference counter, this is useless for string constants} if (right.resultdef.needs_inittable) and (right.nodetype<>stringconstn) then begin location_force_mem(current_asmdata.CurrAsmList,right.location); location_get_data_ref(current_asmdata.CurrAsmList,right.location,href,false); cg.g_incrrefcount(current_asmdata.CurrAsmList,right.resultdef,href); end; if codegenerror then exit; end; releaseright:=true; { shortstring assignments are handled separately } if is_shortstring(left.resultdef) then begin { we can get here only in the following situations for the right node: - empty constant string - char } { The addn is replaced by a blockn or calln that already returns a shortstring } if is_shortstring(right.resultdef) and (right.nodetype in [blockn,calln]) then begin { nothing to do } end { empty constant string } else if (right.nodetype=stringconstn) and (tstringconstnode(right).len=0) then begin cg.a_load_const_ref(current_asmdata.CurrAsmList,OS_8,0,left.location.reference); end { char loading } else if is_char(right.resultdef) then begin if right.nodetype=ordconstn then begin if (target_info.endian = endian_little) then cg.a_load_const_ref(current_asmdata.CurrAsmList,OS_16,(tordconstnode(right).value.svalue shl 8) or 1, left.location.reference) else cg.a_load_const_ref(current_asmdata.CurrAsmList,OS_16,tordconstnode(right).value.svalue or (1 shl 8), left.location.reference); end else begin href:=left.location.reference; cg.a_load_const_ref(current_asmdata.CurrAsmList,OS_8,1,href); inc(href.offset,1); case right.location.loc of LOC_REGISTER, LOC_CREGISTER : begin r:=cg.makeregsize(current_asmdata.CurrAsmList,right.location.register,OS_8); cg.a_load_reg_ref(current_asmdata.CurrAsmList,OS_8,OS_8,r,href); end; LOC_REFERENCE, LOC_CREFERENCE : cg.a_load_ref_ref(current_asmdata.CurrAsmList,OS_8,OS_8,right.location.reference,href); else internalerror(200205111); end; end; end else internalerror(200204249); end { try to reuse memory locations instead of copying } { copy to a memory location ... } else if (right.location.loc = LOC_REFERENCE) and maybechangetemp(current_asmdata.CurrAsmList,left,right.location.reference) then begin { if it worked, we're done } end else begin { SSA support } maybechangeloadnodereg(current_asmdata.CurrAsmList,left,false); maybechangeloadnodereg(current_asmdata.CurrAsmList,right,true); case right.location.loc of LOC_CONSTANT : begin {$ifndef cpu64bit} if right.location.size in [OS_64,OS_S64] then cg64.a_load64_const_loc(current_asmdata.CurrAsmList,right.location.value64,left.location) else {$endif cpu64bit} cg.a_load_const_loc(current_asmdata.CurrAsmList,right.location.value,left.location); end; LOC_REFERENCE, LOC_CREFERENCE : begin case left.location.loc of LOC_REGISTER, LOC_CREGISTER : begin {$ifndef cpu64bit} if left.location.size in [OS_64,OS_S64] then cg64.a_load64_ref_reg(current_asmdata.CurrAsmList,right.location.reference,left.location.register64) else {$endif cpu64bit} cg.a_load_ref_reg(current_asmdata.CurrAsmList,right.location.size,left.location.size,right.location.reference,left.location.register); end; LOC_FPUREGISTER, LOC_CFPUREGISTER : begin cg.a_loadfpu_ref_reg(current_asmdata.CurrAsmList, right.location.size,left.location.size, right.location.reference, left.location.register); end; LOC_REFERENCE, LOC_CREFERENCE : begin {$warning HACK: unaligned test, maybe remove all unaligned locations (array of char) from the compiler} { Use unaligned copy when the offset is not aligned } len:=left.resultdef.size; if (right.location.reference.offset mod sizeof(aint)<>0) or (left.location.reference.offset mod sizeof(aint)<>0) or (right.resultdef.alignment