fpc/compiler/cg386set.pas
peter 12a80cf3dc * update smartlinking, uses getdatalabel
* renamed ptree.value vars to value_str,value_real,value_set
1998-09-07 18:45:52 +00:00

827 lines
32 KiB
ObjectPascal

{
$Id$
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 secondsetelement(var p : ptree);
procedure secondin(var p : ptree);
procedure secondcase(var p : ptree);
implementation
uses
cobjects,verbose,globals,systems,
symtable,aasm,i386,types,
cgi386,cgai386,tgeni386,temp_gen,hcodegen;
const
bytes2Sxx:array[1..4] of Topsize=(S_B,S_W,S_NO,S_L);
{*****************************************************************************
SecondSetElement
*****************************************************************************}
procedure secondsetelement(var p : ptree);
begin
{ load first value in 32bit register }
secondpass(p^.left);
if p^.left^.location.loc in [LOC_REGISTER,LOC_CREGISTER] then
emit_to_reg32(p^.left^.location.register);
{ also a second value ? }
if assigned(p^.right) then
begin
secondpass(p^.right);
if p^.right^.location.loc in [LOC_REGISTER,LOC_CREGISTER] then
emit_to_reg32(p^.right^.location.register);
end;
{ we doesn't modify the left side, we check only the type }
set_location(p^.location,p^.left^.location);
end;
{*****************************************************************************
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
use_small,
pushed,
ranges : boolean;
hr,hr2,
pleftreg : tregister;
opsize : topsize;
setparts : array[1..8] of Tsetpart;
i,numparts : byte;
href,href2 : Treference;
l,l2 : plabel;
function analizeset(Aset:pconstset;is_small:boolean):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 }
if cs_littlesize in aktglobalswitches then
maxcompares:=8
else
maxcompares:=5;
{ when smallset is possible allow only 3 compares the smallset
code is for littlesize also smaller when more compares are used }
if is_small then
maxcompares:=3;
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
{ 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);
if codegenerror then
exit;
{ ofcourse not commutative }
if p^.swaped then
swaptree(p);
{ check if we can use smallset operation using btl which is limited
to 32 bits, the left side may also not contain higher values !! }
use_small:=(psetdef(p^.right^.resulttype)^.settype=smallset) and
((p^.left^.resulttype^.deftype=orddef) and (porddef(p^.left^.resulttype)^.high<=32) or
(p^.left^.resulttype^.deftype=enumdef) and (penumdef(p^.left^.resulttype)^.max<=32));
{ Can we generate jumps? Possible for all types of sets }
if (p^.right^.treetype=setconstn) and
analizeset(p^.right^.value_set,use_small) 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 }
{ 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_AX..R_DX] then
begin
exprasmlist^.concat(new(pai386,op_const_reg(A_AND,S_W,255,pleftreg)));
opsize:=S_W;
end
else
if pleftreg in [R_EAX..R_EDI] then
begin
exprasmlist^.concat(new(pai386,op_const_reg(A_AND,S_L,255,pleftreg)));
opsize:=S_L;
end
else
opsize:=S_B;
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;
reset_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 }
reset_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 dont 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
{ We will now generated code to check the set itself, no jmps,
handle smallsets separate, because it allows faster checks }
if use_small then
begin
if p^.left^.treetype=ordconstn then
begin
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
case p^.left^.location.loc of
LOC_REGISTER,
LOC_CREGISTER:
begin
hr:=p^.left^.location.register;
emit_to_reg32(hr);
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 easier 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
del_reference(p^.right^.location.reference);
if p^.right^.location.reference.isintvalue then
begin
{ We have to load the value into a register because
btl does not accept values only refs or regs (PFV) }
hr2:=getregister32;
exprasmlist^.concat(new(pai386,op_const_reg(A_MOV,S_L,
p^.right^.location.reference.offset,hr2)));
exprasmlist^.concat(new(pai386,op_reg_reg(A_BT,S_L,hr,hr2)));
ungetregister32(hr2);
end
else
exprasmlist^.concat(new(pai386,op_reg_ref(A_BT,S_L,hr,
newreference(p^.right^.location.reference))));
end;
end;
ungetregister32(hr);
p^.location.loc:=LOC_FLAGS;
p^.location.resflags:=F_C;
end;
end
else
begin
{ do search in a normal set which could have >32 elementsm
but also used if the left side contains higher values > 32 }
if p^.left^.treetype=ordconstn then
begin
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
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_JBE,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;
begin
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 aktlocalswitches) 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 aktlocalswitches) 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:
hregister:=p^.left^.location.register;
LOC_CREGISTER:
begin
hregister:=getregister32;
case opsize of
S_B : hregister:=reg32toreg8(hregister);
S_W : hregister:=reg32toreg16(hregister);
end;
exprasmlist^.concat(new(pai386,op_reg_reg(A_MOV,opsize,
p^.left^.location.register,hregister)));
end;
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=Class386 then
inc(max_linear_list,3);
if aktoptprocessor=ClassP5 then
inc(max_linear_list,6);
if aktoptprocessor>=ClassP6 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);
{ don't come back to case line }
aktfilepos:=exprasmlist^.getlasttaifilepos^;
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 1.13 1998-09-07 18:45:54 peter
* update smartlinking, uses getdatalabel
* renamed ptree.value vars to value_str,value_real,value_set
Revision 1.12 1998/09/05 23:51:05 florian
* possible bug with too few registers in first/secondin fixed
Revision 1.11 1998/09/04 08:41:41 peter
* updated some error messages
Revision 1.10 1998/09/03 17:08:40 pierre
* better lines for stabs
(no scroll back to if before else part
no return to case line at jump outside case)
+ source lines also if not in order
Revision 1.9 1998/08/28 10:54:19 peter
* fixed smallset generation from elements, it has never worked before!
Revision 1.8 1998/08/25 11:51:46 peter
* fixed -15 seen as byte in case
Revision 1.7 1998/08/19 16:07:38 jonas
* changed optimizer switches + cleanup of DestroyRefs in daopt386.pas
Revision 1.6 1998/08/18 09:24:39 pierre
* small warning position bug fixed
* support_mmx switches splitting was missing
* rhide error and warning output corrected
Revision 1.5 1998/08/14 18:18:40 peter
+ dynamic set contruction
* smallsets are now working (always longint size)
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
}