{ $Id$ Copyright (c) 1993-98 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 cg386set; interface uses tree; procedure secondin(var p : ptree); procedure secondcase(var p : ptree); implementation uses cobjects,verbose,globals,systems, symtable,aasm,i386,types, cgi386,cgai386,tgeni386,hcodegen; const bytes2Sxx:array[1..4] of Topsize=(S_B,S_W,S_NO,S_L); {***************************************************************************** SecondIn *****************************************************************************} procedure secondin(var p : ptree); type Tsetpart=record range:boolean; {Part is a range.} start,stop:byte; {Start/stop when range; Stop=element when an element.} end; var pushed,ranges : boolean; hr,pleftreg : tregister; opsize : topsize; setparts:array[1..8] of Tsetpart; i,numparts:byte; href,href2:Treference; l,l2 : plabel; function analizeset(Aset:Pconstset):boolean; type byteset=set of byte; var compares,maxcompares:word; i:byte; begin analizeset:=false; ranges:=false; numparts:=0; compares:=0; {Lots of comparisions take a lot of time, so do not allow too much comparisions. 8 comparisions are, however, still smalller than emitting the set.} maxcompares:=5; if cs_littlesize in aktglobalswitches then maxcompares:=8; for i:=0 to 255 do if i in byteset(Aset^) then begin if (numparts=0) or (i<>setparts[numparts].stop+1) then begin {Set element is a separate element.} inc(compares); if compares>maxcompares then exit; inc(numparts); setparts[numparts].range:=false; setparts[numparts].stop:=i; end else {Set element is part of a range.} if not setparts[numparts].range then begin {Transform an element into a range.} setparts[numparts].range:=true; setparts[numparts].start:= setparts[numparts].stop; setparts[numparts].stop:=i; inc(compares); if compares>maxcompares then exit; end else begin {Extend a range.} setparts[numparts].stop:=i; {A range of two elements can better be checked as two separate ones. When extending a range, our range becomes larger than two elements.} ranges:=true; end; end; analizeset:=true; end; begin if psetdef(p^.right^.resulttype)^.settype=smallset then begin if p^.left^.treetype=ordconstn then begin { only compulsory } secondpass(p^.left); secondpass(p^.right); if codegenerror then exit; p^.location.resflags:=F_NE; case p^.right^.location.loc of LOC_REGISTER,LOC_CREGISTER: begin exprasmlist^.concat(new(pai386,op_const_reg( A_TEST,S_L,1 shl (p^.left^.value and 31), p^.right^.location.register))); ungetregister32(p^.right^.location.register); end else begin exprasmlist^.concat(new(pai386,op_const_ref(A_TEST,S_L,1 shl (p^.left^.value and 31), newreference(p^.right^.location.reference)))); del_reference(p^.right^.location.reference); end; end; end else begin { calculate both operators } { the complex one first } firstcomplex(p); secondpass(p^.left); { are too few registers free? } pushed:=maybe_push(p^.right^.registers32,p^.left); secondpass(p^.right); if pushed then restore(p^.left); { of course not commutative } if p^.swaped then swaptree(p); case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER: begin hr:=p^.left^.location.register; case p^.left^.location.register of R_AX,R_BX,R_CX,R_DX,R_DI,R_SI,R_SP : begin hr:=reg16toreg32(p^.left^.location.register); ungetregister32(hr); exprasmlist^.concat(new(pai386,op_reg_reg(A_MOVZX,S_WL, p^.left^.location.register,hr))); end; R_AL,R_BL,R_CL,R_DL : begin hr:=reg8toreg32(p^.left^.location.register); ungetregister32(hr); exprasmlist^.concat(new(pai386,op_reg_reg(A_MOVZX,S_BL, p^.left^.location.register,hr))); end; end; end; else begin { the set element isn't never samller than a byte } { and because it's a small set we need only 5 bits } { but 8 bits are eaiser to load } exprasmlist^.concat(new(pai386,op_ref_reg(A_MOVZX,S_BL, newreference(p^.left^.location.reference),R_EDI))); hr:=R_EDI; del_reference(p^.left^.location.reference); end; end; case p^.right^.location.loc of LOC_REGISTER, LOC_CREGISTER: exprasmlist^.concat(new(pai386,op_reg_reg(A_BT,S_L,hr, p^.right^.location.register))); else begin exprasmlist^.concat(new(pai386,op_reg_ref(A_BT,S_L,hr, newreference(p^.right^.location.reference)))); del_reference(p^.right^.location.reference); end; end; p^.location.loc:=LOC_FLAGS; p^.location.resflags:=F_C; end; end else begin if p^.left^.treetype=ordconstn then begin { only compulsory } secondpass(p^.left); secondpass(p^.right); if codegenerror then exit; p^.location.resflags:=F_NE; inc(p^.right^.location.reference.offset,p^.left^.value shr 3); exprasmlist^.concat(new(pai386,op_const_ref(A_TEST,S_B,1 shl (p^.left^.value and 7), newreference(p^.right^.location.reference)))); del_reference(p^.right^.location.reference); end else begin if (p^.right^.treetype=setconstrn) and analizeset(p^.right^.constset) then begin {It gives us advantage to check for the set elements separately instead of using the SET_IN_BYTE procedure. To do: Build in support for LOC_JUMP.} secondpass(p^.left); {We won't do a second pass on p^.right, because this will emit the constant set.} {If register is used, use only lower 8 bits} if p^.left^.location.loc in [LOC_REGISTER,LOC_CREGISTER] then begin pleftreg:=p^.left^.location.register; if pleftreg in [R_AL..R_DH] then begin exprasmlist^.concat(new(pai386,op_const_reg( A_AND,S_B,255,pleftreg))); opsize:=S_B; end else begin exprasmlist^.concat(new(pai386,op_const_reg( A_AND,S_L,255,pleftreg))); if pleftreg in [R_EAX..R_EDI] then opsize:=S_L else opsize:=S_W; end; end; {Get a label to jump to the end.} p^.location.loc:=LOC_FLAGS; {It's better to use the zero flag when there are no ranges.} if ranges then p^.location.resflags:=F_C else p^.location.resflags:=F_E; href.symbol := nil; clear_reference(href); getlabel(l); href.symbol:=stringdup(lab2str(l)); for i:=1 to numparts do if setparts[i].range then begin {Check if left is in a range.} {Get a label to jump over the check.} href2.symbol := nil; clear_reference(href2); getlabel(l2); href.symbol:=stringdup(lab2str(l2)); if setparts[i].start=setparts[i].stop-1 then begin case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER : exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize, setparts[i].start,pleftreg))); else exprasmlist^.concat(new(pai386,op_const_ref(A_CMP,S_B, setparts[i].start,newreference(p^.left^.location.reference)))); end; {Result should be in carry flag when ranges are used.} if ranges then exprasmlist^.concat(new(pai386,op_none(A_STC,S_NO))); {If found, jump to end.} emitl(A_JE,l); case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER: exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize, setparts[i].stop,pleftreg))); else exprasmlist^.concat(new(pai386,op_const_ref(A_CMP,S_B, setparts[i].stop,newreference(p^.left^.location.reference)))); end; {Result should be in carry flag when ranges are used.} if ranges then exprasmlist^.concat(new(pai386,op_none(A_STC,S_NO))); {If found, jump to end.} emitl(A_JE,l); end else begin if setparts[i].start<>0 then begin { We only check for the lower bound if it is > 0, because set elements lower than 0 do nt exist.} case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER : exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize, setparts[i].start,pleftreg))); else exprasmlist^.concat(new(pai386,op_const_ref(A_CMP,S_B, setparts[i].start,newreference(p^.left^.location.reference)))); end; {If lower, jump to next check.} emitl(A_JB,l2); end; { We only check for the high bound if it is < 255, because set elements higher than 255 do nt exist, the its always true, so only a JMP is generated } if setparts[i].stop<>255 then begin case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER : exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize, setparts[i].stop+1,pleftreg))); else exprasmlist^.concat(new(pai386,op_const_ref(A_CMP,S_B, setparts[i].stop+1,newreference(p^.left^.location.reference)))); end; {If higher, element is in set.} emitl(A_JB,l); end else begin exprasmlist^.concat(new(pai386,op_none(A_STC,S_NO))); emitl(A_JMP,l); end; end; {Emit the jump over label.} exprasmlist^.concat(new(pai_label,init(l2))); end else begin {Emit code to check if left is an element.} case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER: exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize, setparts[i].stop,pleftreg))); else exprasmlist^.concat(new(pai386,op_const_ref(A_CMP,S_B, setparts[i].stop,newreference(p^.left^.location.reference)))); end; {Result should be in carry flag when ranges are used.} if ranges then exprasmlist^.concat(new(pai386,op_none(A_STC,S_NO))); {If found, jump to end.} emitl(A_JE,l); end; if ranges then exprasmlist^.concat(new(pai386,op_none(A_CLC,S_NO))); {To compensate for not doing a second pass.} stringdispose(p^.right^.location.reference.symbol); {Now place the end label.} exprasmlist^.concat(new(pai_label,init(l))); case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER: ungetregister32(pleftreg); else del_reference(p^.left^.location.reference); end; end else begin { calculate both operators } { the complex one first } firstcomplex(p); secondpass(p^.left); { are too few registers free? } pushed:=maybe_push(p^.right^.registers32,p); secondpass(p^.right); if pushed then restore(p); { of course not commutative } if p^.swaped then swaptree(p); pushsetelement(p^.left); emitpushreferenceaddr(exprasmlist,p^.right^.location.reference); del_reference(p^.right^.location.reference); { registers need not be save. that happens in SET_IN_BYTE } { (EDI is changed) } emitcall('SET_IN_BYTE',true); { ungetiftemp(p^.right^.location.reference); } p^.location.loc:=LOC_FLAGS; p^.location.resflags:=F_C; end; end; end; end; {***************************************************************************** SecondCase *****************************************************************************} procedure secondcase(var p : ptree); var with_sign : boolean; opsize : topsize; jmp_gt,jmp_le,jmp_lee : tasmop; hp : ptree; { register with case expression } hregister : tregister; endlabel,elselabel : plabel; { true, if we can omit the range check of the jump table } jumptable_no_range : boolean; { where to put the jump table } jumpsegment : paasmoutput; procedure gentreejmp(p : pcaserecord); var lesslabel,greaterlabel : plabel; begin emitl(A_LABEL,p^._at); { calculate labels for left and right } if (p^.less=nil) then lesslabel:=elselabel else lesslabel:=p^.less^._at; if (p^.greater=nil) then greaterlabel:=elselabel else greaterlabel:=p^.greater^._at; { calculate labels for left and right } { no range label: } if p^._low=p^._high then begin exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize,p^._low,hregister))); if greaterlabel=lesslabel then begin emitl(A_JNE,lesslabel); end else begin emitl(jmp_le,lesslabel); emitl(jmp_gt,greaterlabel); end; emitl(A_JMP,p^.statement); end else begin exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize,p^._low,hregister))); emitl(jmp_le,lesslabel); exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize,p^._high,hregister))); emitl(jmp_gt,greaterlabel); emitl(A_JMP,p^.statement); end; if assigned(p^.less) then gentreejmp(p^.less); if assigned(p^.greater) then gentreejmp(p^.greater); end; procedure genlinearlist(hp : pcaserecord); var first : boolean; last : longint; {helplabel : longint;} procedure genitem(t : pcaserecord); begin if assigned(t^.less) then genitem(t^.less); if t^._low=t^._high then begin if t^._low-last=1 then exprasmlist^.concat(new(pai386,op_reg(A_DEC,opsize,hregister))) else if t^._low-last=0 then exprasmlist^.concat(new(pai386,op_reg_reg(A_OR,opsize,hregister,hregister))) else exprasmlist^.concat(new(pai386,op_const_reg(A_SUB,opsize,t^._low-last,hregister))); last:=t^._low; emitl(A_JZ,t^.statement); 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 if t^._low-1=1 then exprasmlist^.concat(new(pai386,op_reg(A_DEC,opsize, hregister))) else if t^._low-1=0 then exprasmlist^.concat(new(pai386,op_reg_reg(A_OR,opsize, hregister,hregister))) else exprasmlist^.concat(new(pai386,op_const_reg(A_SUB,opsize, t^._low-1,hregister))); { work around: if the lower range=0 and we do the subtraction we have to take care of the sign! } if t^._low=0 then emitl(A_JLE,elselabel) else emitl(jmp_lee,elselabel); end { 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: } else if (t^._low-last>1)then begin if t^._low-last-1=1 then exprasmlist^.concat(new(pai386,op_reg(A_DEC,opsize,hregister))) else exprasmlist^.concat(new(pai386,op_const_reg(A_SUB,opsize,t^._low-last-1,hregister))); emitl(jmp_lee,elselabel); end; exprasmlist^.concat(new(pai386,op_const_reg(A_SUB,opsize,t^._high-t^._low+1,hregister))); emitl(jmp_lee,t^.statement); last:=t^._high; end; first:=false; if assigned(t^.greater) then genitem(t^.greater); end; var hr : tregister; begin { case register is modified by the list evalution } if (p^.left^.location.loc=LOC_CREGISTER) then begin hr:=getregister32; case opsize of S_B : hregister:=reg32toreg8(hr); S_W : hregister:=reg32toreg16(hr); S_L : hregister:=hr; end; end; last:=0; first:=true; genitem(hp); emitl(A_JMP,elselabel); end; procedure genjumptable(hp : pcaserecord;min_,max_ : longint); var table : plabel; last : longint; hr : preference; procedure genitem(t : pcaserecord); var i : longint; begin if assigned(t^.less) then genitem(t^.less); { fill possible hole } for i:=last+1 to t^._low-1 do jumpsegment^.concat(new(pai_const,init_symbol(strpnew(lab2str (elselabel))))); for i:=t^._low to t^._high do jumpsegment^.concat(new(pai_const,init_symbol(strpnew(lab2str (t^.statement))))); last:=t^._high; if assigned(t^.greater) then genitem(t^.greater); end; begin if not(jumptable_no_range) then begin exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize,min_,hregister))); { case expr less than min_ => goto elselabel } emitl(jmp_le,elselabel); exprasmlist^.concat(new(pai386,op_const_reg(A_CMP,opsize,max_,hregister))); emitl(jmp_gt,elselabel); end; getlabel(table); { extend with sign } if opsize=S_W then begin exprasmlist^.concat(new(pai386,op_reg_reg(A_MOVZX,S_WL,hregister, reg16toreg32(hregister)))); hregister:=reg16toreg32(hregister); end else if opsize=S_B then begin exprasmlist^.concat(new(pai386,op_reg_reg(A_MOVZX,S_BL,hregister, reg8toreg32(hregister)))); hregister:=reg8toreg32(hregister); end; new(hr); reset_reference(hr^); hr^.symbol:=stringdup(lab2str(table)); hr^.offset:=(-min_)*4; hr^.index:=hregister; hr^.scalefactor:=4; exprasmlist^.concat(new(pai386,op_ref(A_JMP,S_NO,hr))); { !!!!! generate tables if not(cs_littlesize in aktswitches^ ) then jumpsegment^.concat(new(pai386,op_const(A_ALIGN,S_NO,4))); } jumpsegment^.concat(new(pai_label,init(table))); last:=min_; genitem(hp); { !!!!!!! if not(cs_littlesize in aktswitches^ ) then exprasmlist^.concat(new(pai386,op_const(A_ALIGN,S_NO,4))); } end; var lv,hv,min_label,max_label,labels : longint; max_linear_list : longint; begin getlabel(endlabel); getlabel(elselabel); if (cs_smartlink in aktmoduleswitches) then jumpsegment:=procinfo.aktlocaldata else jumpsegment:=datasegment; with_sign:=is_signed(p^.left^.resulttype); if with_sign then begin jmp_gt:=A_JG; jmp_le:=A_JL; jmp_lee:=A_JLE; end else begin jmp_gt:=A_JA; jmp_le:=A_JB; jmp_lee:=A_JBE; end; cleartempgen; secondpass(p^.left); { determines the size of the operand } opsize:=bytes2Sxx[p^.left^.resulttype^.size]; { copy the case expression to a register } case p^.left^.location.loc of LOC_REGISTER, LOC_CREGISTER: hregister:=p^.left^.location.register; LOC_MEM,LOC_REFERENCE : begin del_reference(p^.left^.location.reference); hregister:=getregister32; case opsize of S_B : hregister:=reg32toreg8(hregister); S_W : hregister:=reg32toreg16(hregister); end; exprasmlist^.concat(new(pai386,op_ref_reg(A_MOV,opsize,newreference( p^.left^.location.reference),hregister))); end; else internalerror(2002); end; { now generate the jumps } if cs_optimize in aktglobalswitches then begin { procedures are empirically passed on } { consumption can also be calculated } { but does it pay on the different } { processors? } { moreover can the size only be appro- } { ximated as it is not known if rel8, } { rel16 or rel32 jumps are used } min_label:=case_get_min(p^.nodes); max_label:=case_get_max(p^.nodes); labels:=case_count_labels(p^.nodes); { can we omit the range check of the jump table } getrange(p^.left^.resulttype,lv,hv); jumptable_no_range:=(lv=min_label) and (hv=max_label); { optimize for size ? } if cs_littlesize in aktglobalswitches then begin if (labels<=2) or ((max_label-min_label)>3*labels) then { a linear list is always smaller than a jump tree } genlinearlist(p^.nodes) else { if the labels less or more a continuum then } genjumptable(p^.nodes,min_label,max_label); end else begin if jumptable_no_range then max_linear_list:=4 else max_linear_list:=2; { a jump table crashes the pipeline! } if aktoptprocessor=int486 then inc(max_linear_list,3); if aktoptprocessor=pentium then inc(max_linear_list,6); if aktoptprocessor>=pentiumpro then inc(max_linear_list,9); if (labels<=max_linear_list) then genlinearlist(p^.nodes) else begin if ((max_label-min_label)>4*labels) then begin if labels>16 then gentreejmp(p^.nodes) else genlinearlist(p^.nodes); end else genjumptable(p^.nodes,min_label,max_label); end; end; end else { it's always not bad } genlinearlist(p^.nodes); { now generate the instructions } hp:=p^.right; while assigned(hp) do begin cleartempgen; secondpass(hp^.right); emitl(A_JMP,endlabel); hp:=hp^.left; end; emitl(A_LABEL,elselabel); { ...and the else block } if assigned(p^.elseblock) then begin cleartempgen; secondpass(p^.elseblock); end; emitl(A_LABEL,endlabel); end; end. { $Log$ Revision 1.4 1998-08-10 14:49:51 peter + localswitches, moduleswitches, globalswitches splitting Revision 1.3 1998/06/25 08:48:10 florian * first version of rtti support Revision 1.2 1998/06/16 08:56:18 peter + targetcpu * cleaner pmodules for newppu Revision 1.1 1998/06/05 17:44:13 peter * splitted cgi386 }