{ Copyright (c) 1998-2002 by Florian Klaempfl Generate i386 assembler for in set/case 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 n386set; {$i fpcdefs.inc} interface uses globtype, node,nset,pass_1,ncgset; type ti386casenode = class(tcgcasenode) procedure optimizevalues(var max_linear_list:aint;var max_dist:aword);override; function has_jumptable : boolean;override; procedure genjumptable(hp : pcaselabel;min_,max_ : aint);override; procedure genlinearlist(hp : pcaselabel);override; end; implementation uses systems, verbose,globals,constexp, symconst,symdef,defutil, aasmbase,aasmtai,aasmdata,aasmcpu, cgbase,pass_2, ncon, cpubase,cpuinfo,procinfo, cga,cgutils,cgobj,ncgutil, cgx86; {***************************************************************************** TI386CASENODE *****************************************************************************} procedure ti386casenode.optimizevalues(var max_linear_list:aint;var max_dist:aword); begin { a jump table crashes the pipeline! } if current_settings.optimizecputype=cpu_386 then inc(max_linear_list,3) else if current_settings.optimizecputype=cpu_Pentium then inc(max_linear_list,6) else if current_settings.optimizecputype in [cpu_Pentium2,cpu_Pentium3] then inc(max_linear_list,9) else if current_settings.optimizecputype=cpu_Pentium4 then inc(max_linear_list,14); end; function ti386casenode.has_jumptable : boolean; begin has_jumptable:=true; end; procedure ti386casenode.genjumptable(hp : pcaselabel;min_,max_ : aint); var table : tasmlabel; last : TConstExprInt; indexreg : tregister; href : treference; jtlist: tasmlist; sectype: TAsmSectiontype; procedure genitem(list:TAsmList;t : pcaselabel); var i : aint; begin if assigned(t^.less) then genitem(list,t^.less); { fill possible hole } for i:=last.svalue+1 to t^._low.svalue-1 do list.concat(Tai_const.Create_sym(elselabel)); for i:=t^._low.svalue to t^._high.svalue do list.concat(Tai_const.Create_sym(blocklabel(t^.blockid))); last:=t^._high; if assigned(t^.greater) then genitem(list,t^.greater); end; begin last:=min_; if not(jumptable_no_range) then begin { a <= x <= b <-> unsigned(x-a) <= (b-a) } cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SUB,opsize,aint(min_),hregister); { case expr greater than max_ => goto elselabel } cg.a_cmp_const_reg_label(current_asmdata.CurrAsmList,opsize,OC_A,aint(max_)-aint(min_),hregister,elselabel); min_:=0; end; current_asmdata.getjumplabel(table); { make it a 32bit register } indexreg:=cg.makeregsize(current_asmdata.CurrAsmList,hregister,OS_INT); cg.a_load_reg_reg(current_asmdata.CurrAsmList,opsize,OS_INT,hregister,indexreg); { create reference } reference_reset_symbol(href,table,0); href.offset:=(-aint(min_))*4; href.index:=indexreg; href.scalefactor:=4; emit_ref(A_JMP,S_NO,href); { generate jump table } if (target_info.system = system_i386_darwin) then begin jtlist:=current_asmdata.asmlists[al_const]; sectype:=sec_rodata; end else begin jtlist:=current_procinfo.aktlocaldata; sectype:=sec_data; end; new_section(jtlist,sectype,current_procinfo.procdef.mangledname,sizeof(aint)); jtlist.concat(Tai_label.Create(table)); genitem(jtlist,hp); end; procedure ti386casenode.genlinearlist(hp : pcaselabel); var first : boolean; lastrange : boolean; last : TConstExprInt; cond_lt,cond_le : tresflags; procedure genitem(t : pcaselabel); begin if assigned(t^.less) then genitem(t^.less); { need we to test the first value } if first and (t^._low>get_min_value(left.resultdef)) then begin cg.a_cmp_const_reg_label(current_asmdata.CurrAsmList,opsize,jmp_lt,aint(t^._low.svalue),hregister,elselabel); end; if t^._low=t^._high then begin if t^._low-last=0 then cg.a_cmp_const_reg_label(current_asmdata.CurrAsmList, opsize, OC_EQ,0,hregister,blocklabel(t^.blockid)) else begin cg.a_op_const_reg(current_asmdata.CurrAsmList, OP_SUB, opsize, aint(t^._low.svalue-last.svalue), hregister); cg.a_jmp_flags(current_asmdata.CurrAsmList,F_E,blocklabel(t^.blockid)); end; last:=t^._low; lastrange:=false; end else begin { it begins with the smallest label, if the value } { is even smaller then jump immediately to the } { ELSE-label } if first then begin { have we to ajust the first value ? } if (t^._low>get_min_value(left.resultdef)) or (get_min_value(left.resultdef)<>0) then cg.a_op_const_reg(current_asmdata.CurrAsmList, OP_SUB, opsize, aint(t^._low.svalue), hregister); end else begin { if there is no unused label between the last and the } { present label then the lower limit can be checked } { immediately. else check the range in between: } cg.a_op_const_reg(current_asmdata.CurrAsmList, OP_SUB, opsize, aint(t^._low.svalue-last.svalue), hregister); { no jump necessary here if the new range starts at } { at the value following the previous one } if ((t^._low-last) <> 1) or (not lastrange) then cg.a_jmp_flags(current_asmdata.CurrAsmList,cond_lt,elselabel); end; {we need to use A_SUB, because A_DEC does not set the correct flags, therefor using a_op_const_reg(OP_SUB) is not possible } emit_const_reg(A_SUB,TCGSize2OpSize[opsize],aint(t^._high.svalue-t^._low.svalue),hregister); cg.a_jmp_flags(current_asmdata.CurrAsmList,cond_le,blocklabel(t^.blockid)); last:=t^._high; lastrange:=true; end; first:=false; if assigned(t^.greater) then genitem(t^.greater); end; begin if with_sign then begin cond_lt:=F_L; cond_le:=F_LE; end else begin cond_lt:=F_B; cond_le:=F_BE; end; { do we need to generate cmps? } if (with_sign and (min_label<0)) then genlinearcmplist(hp) else begin last:=0; lastrange:=false; first:=true; genitem(hp); cg.a_jmp_always(current_asmdata.CurrAsmList,elselabel); end; end; begin ccasenode:=ti386casenode; end.