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fpc/compiler/i386/daopt386.pas
Jonas Maebe 1f6ec379de * moved field definitions before method/property definitions (see mantis 
#13971)

git-svn-id: trunk@13330 -
2009-06-27 11:27:31 +00:00

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{
Copyright (c) 1998-2002 by Jonas Maebe, member of the Freepascal
development team
This unit contains the data flow analyzer and several helper procedures
and functions.
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 daopt386;
{$i fpcdefs.inc}
interface
uses
globtype,
cclasses,aasmbase,aasmtai,aasmdata,aasmcpu,cgbase,cgutils,
cpubase;
{******************************* Constants *******************************}
const
{ Possible register content types }
con_Unknown = 0;
con_ref = 1;
con_const = 2;
{ The contents aren't usable anymore for CSE, but they may still be }
{ usefull for detecting whether the result of a load is actually used }
con_invalid = 3;
{ the reverse of the above (in case a (conditional) jump is encountered): }
{ CSE is still possible, but the original instruction can't be removed }
con_noRemoveRef = 4;
{ same, but for constants }
con_noRemoveConst = 5;
const
topsize2tcgsize: array[topsize] of tcgsize = (OS_NO,
OS_8,OS_16,OS_32,OS_64,OS_16,OS_32,OS_32,
OS_16,OS_32,OS_64,
OS_F32,OS_F64,OS_F80,OS_C64,OS_F128,
OS_M32,
OS_ADDR,OS_NO,OS_NO,
OS_NO,
OS_NO);
{********************************* Types *********************************}
type
TRegEnum = RS_EAX..RS_ESP;
TRegArray = Array[TRegEnum] of tsuperregister;
TRegSet = Set of TRegEnum;
toptreginfo = Record
NewRegsEncountered, OldRegsEncountered: TRegSet;
RegsLoadedForRef: TRegSet;
lastReload: array[RS_EAX..RS_ESP] of tai;
New2OldReg: TRegArray;
end;
{possible actions on an operand: read, write or modify (= read & write)}
TOpAction = (OpAct_Read, OpAct_Write, OpAct_Modify, OpAct_Unknown);
{the possible states of a flag}
TFlagContents = (F_Unknown, F_notSet, F_Set);
TContent = Packed Record
{start and end of block instructions that defines the
content of this register.}
StartMod: tai;
MemWrite: taicpu;
{how many instructions starting with StarMod does the block consist of}
NrOfMods: Word;
{the type of the content of the register: unknown, memory, constant}
Typ: Byte;
case byte of
{starts at 0, gets increased everytime the register is written to}
1: (WState: Byte;
{starts at 0, gets increased everytime the register is read from}
RState: Byte);
{ to compare both states in one operation }
2: (state: word);
end;
{Contents of the integer registers}
TRegContent = Array[RS_EAX..RS_ESP] Of TContent;
{contents of the FPU registers}
// TRegFPUContent = Array[RS_ST..RS_ST7] Of TContent;
{$ifdef tempOpts}
{ linked list which allows searching/deleting based on value, no extra frills}
PSearchLinkedListItem = ^TSearchLinkedListItem;
TSearchLinkedListItem = object(TLinkedList_Item)
constructor init;
function equals(p: PSearchLinkedListItem): boolean; virtual;
end;
PSearchDoubleIntItem = ^TSearchDoubleInttem;
TSearchDoubleIntItem = object(TLinkedList_Item)
constructor init(_int1,_int2: longint);
function equals(p: PSearchLinkedListItem): boolean; virtual;
private
int1, int2: longint;
end;
PSearchLinkedList = ^TSearchLinkedList;
TSearchLinkedList = object(TLinkedList)
function searchByValue(p: PSearchLinkedListItem): boolean;
procedure removeByValue(p: PSearchLinkedListItem);
end;
{$endif tempOpts}
{information record with the contents of every register. Every tai object
gets one of these assigned: a pointer to it is stored in the OptInfo field}
TtaiProp = Record
Regs: TRegContent;
{ FPURegs: TRegFPUContent;} {currently not yet used}
{ allocated Registers }
UsedRegs: TRegSet;
{ status of the direction flag }
DirFlag: TFlagContents;
{$ifdef tempOpts}
{ currently used temps }
tempAllocs: PSearchLinkedList;
{$endif tempOpts}
{ can this instruction be removed? }
CanBeRemoved: Boolean;
{ are the resultflags set by this instruction used? }
FlagsUsed: Boolean;
end;
ptaiprop = ^TtaiProp;
TtaiPropBlock = Array[1..250000] Of TtaiProp;
PtaiPropBlock = ^TtaiPropBlock;
TInstrSinceLastMod = Array[RS_EAX..RS_ESP] Of Word;
TLabelTableItem = Record
taiObj: tai;
{$ifDef JumpAnal}
InstrNr: Longint;
RefsFound: Word;
JmpsProcessed: Word
{$endif JumpAnal}
end;
TLabelTable = Array[0..2500000] Of TLabelTableItem;
PLabelTable = ^TLabelTable;
{*********************** procedures and functions ************************}
procedure InsertLLItem(AsmL: TAsmList; prev, foll, new_one: TLinkedListItem);
function RefsEqual(const R1, R2: TReference): Boolean;
function isgp32reg(supreg: tsuperregister): Boolean;
function reginref(supreg: tsuperregister; const ref: treference): boolean;
function RegReadByInstruction(supreg: tsuperregister; hp: tai): boolean;
function RegModifiedByInstruction(supreg: tsuperregister; p1: tai): boolean;
function RegInInstruction(supreg: tsuperregister; p1: tai): boolean;
function reginop(supreg: tsuperregister; const o:toper): boolean;
function instrWritesFlags(p: tai): boolean;
function instrReadsFlags(p: tai): boolean;
function writeToMemDestroysContents(regWritten: tsuperregister; const ref: treference;
supreg: tsuperregister; size: tcgsize; const c: tcontent; var invalsmemwrite: boolean): boolean;
function writeToRegDestroysContents(destReg, supreg: tsuperregister;
const c: tcontent): boolean;
function writeDestroysContents(const op: toper; supreg: tsuperregister; size: tcgsize;
const c: tcontent; var memwritedestroyed: boolean): boolean;
function sequenceDependsonReg(const Content: TContent; seqreg: tsuperregister; supreg: tsuperregister): Boolean;
function GetNextInstruction(Current: tai; var Next: tai): Boolean;
function GetLastInstruction(Current: tai; var Last: tai): Boolean;
procedure SkipHead(var p: tai);
function labelCanBeSkipped(p: tai_label): boolean;
procedure RemoveLastDeallocForFuncRes(asmL: TAsmList; p: tai);
function regLoadedWithNewValue(supreg: tsuperregister; canDependOnPrevValue: boolean;
hp: tai): boolean;
procedure UpdateUsedRegs(var UsedRegs: TRegSet; p: tai);
procedure AllocRegBetween(asml: TAsmList; reg: tregister; p1, p2: tai; var initialusedregs: tregset);
function FindRegDealloc(supreg: tsuperregister; p: tai): boolean;
function InstructionsEquivalent(p1, p2: tai; var RegInfo: toptreginfo): Boolean;
function sizescompatible(loadsize,newsize: topsize): boolean;
function OpsEqual(const o1,o2:toper): Boolean;
type
tdfaobj = class
constructor create(_list: TAsmList); virtual;
function pass_1(_blockstart: tai): tai;
function pass_generate_code: boolean;
procedure clear;
function getlabelwithsym(sym: tasmlabel): tai;
private
{ asm list we're working on }
list: TAsmList;
{ current part of the asm list }
blockstart, blockend: tai;
{ the amount of taiObjects in the current part of the assembler list }
nroftaiobjs: longint;
{ Array which holds all TtaiProps }
taipropblock: ptaipropblock;
{ all labels in the current block: their value mapped to their location }
lolab, hilab, labdif: longint;
labeltable: plabeltable;
{ Walks through the list to find the lowest and highest label number, inits the }
{ labeltable and fixes/optimizes some regallocs }
procedure initlabeltable;
function initdfapass2: boolean;
procedure dodfapass2;
end;
function FindLabel(L: tasmlabel; var hp: tai): Boolean;
procedure incState(var S: Byte; amount: longint);
{******************************* Variables *******************************}
var
dfa: tdfaobj;
{*********************** end of Interface section ************************}
Implementation
Uses
{$ifdef csdebug}
cutils,
{$else}
{$ifdef statedebug}
cutils,
{$else}
{$ifdef allocregdebug}
cutils,
{$endif}
{$endif}
{$endif}
globals, systems, verbose, symconst, cgobj,procinfo;
Type
TRefCompare = function(const r1, r2: treference; size1, size2: tcgsize): boolean;
var
{How many instructions are between the current instruction and the last one
that modified the register}
NrOfInstrSinceLastMod: TInstrSinceLastMod;
{$ifdef tempOpts}
constructor TSearchLinkedListItem.init;
begin
end;
function TSearchLinkedListItem.equals(p: PSearchLinkedListItem): boolean;
begin
equals := false;
end;
constructor TSearchDoubleIntItem.init(_int1,_int2: longint);
begin
int1 := _int1;
int2 := _int2;
end;
function TSearchDoubleIntItem.equals(p: PSearchLinkedListItem): boolean;
begin
equals := (TSearchDoubleIntItem(p).int1 = int1) and
(TSearchDoubleIntItem(p).int2 = int2);
end;
function TSearchLinkedList.FindByValue(p: PSearchLinkedListItem): boolean;
var temp: PSearchLinkedListItem;
begin
temp := first;
while (temp <> last.next) and
not(temp.equals(p)) do
temp := temp.next;
searchByValue := temp <> last.next;
end;
procedure TSearchLinkedList.removeByValue(p: PSearchLinkedListItem);
begin
temp := first;
while (temp <> last.next) and
not(temp.equals(p)) do
temp := temp.next;
if temp <> last.next then
begin
remove(temp);
dispose(temp,done);
end;
end;
procedure updateTempAllocs(var UsedRegs: TRegSet; p: tai);
{updates UsedRegs with the RegAlloc Information coming after p}
begin
repeat
while assigned(p) and
((p.typ in (SkipInstr - [ait_RegAlloc])) or
((p.typ = ait_label) and
labelCanBeSkipped(tai_label(current)))) Do
p := tai(p.next);
while assigned(p) and
(p.typ=ait_RegAlloc) Do
begin
case tai_regalloc(p).ratype of
ra_alloc :
Include(UsedRegs, TRegEnum(getsupreg(tai_regalloc(p).reg)));
ra_dealloc :
Exclude(UsedRegs, TRegEnum(getsupreg(tai_regalloc(p).reg)));
end;
p := tai(p.next);
end;
until not(assigned(p)) or
(not(p.typ in SkipInstr) and
not((p.typ = ait_label) and
labelCanBeSkipped(tai_label(current))));
end;
{$endif tempOpts}
{************************ Create the Label table ************************}
function findregalloc(supreg: tsuperregister; starttai: tai; ratyp: tregalloctype): boolean;
{ Returns true if a ait_alloc object for reg is found in the block of tai's }
{ starting with Starttai and ending with the next "real" instruction }
begin
findregalloc := false;
repeat
while assigned(starttai) and
((starttai.typ in (skipinstr - [ait_regalloc])) or
((starttai.typ = ait_label) and
labelcanbeskipped(tai_label(starttai)))) do
starttai := tai(starttai.next);
if assigned(starttai) and
(starttai.typ = ait_regalloc) then
begin
if (tai_regalloc(Starttai).ratype = ratyp) and
(getsupreg(tai_regalloc(Starttai).reg) = supreg) then
begin
findregalloc:=true;
break;
end;
starttai := tai(starttai.next);
end
else
break;
until false;
end;
procedure RemoveLastDeallocForFuncRes(asml: TAsmList; p: tai);
procedure DoRemoveLastDeallocForFuncRes(asml: TAsmList; supreg: tsuperregister);
var
hp2: tai;
begin
hp2 := p;
repeat
hp2 := tai(hp2.previous);
if assigned(hp2) and
(hp2.typ = ait_regalloc) and
(tai_regalloc(hp2).ratype=ra_dealloc) and
(getregtype(tai_regalloc(hp2).reg) = R_INTREGISTER) and
(getsupreg(tai_regalloc(hp2).reg) = supreg) then
begin
asml.remove(hp2);
hp2.free;
break;
end;
until not(assigned(hp2)) or regInInstruction(supreg,hp2);
end;
begin
case current_procinfo.procdef.returndef.typ of
arraydef,recorddef,pointerdef,
stringdef,enumdef,procdef,objectdef,errordef,
filedef,setdef,procvardef,
classrefdef,forwarddef:
DoRemoveLastDeallocForFuncRes(asml,RS_EAX);
orddef:
if current_procinfo.procdef.returndef.size <> 0 then
begin
DoRemoveLastDeallocForFuncRes(asml,RS_EAX);
{ for int64/qword }
if current_procinfo.procdef.returndef.size = 8 then
DoRemoveLastDeallocForFuncRes(asml,RS_EDX);
end;
end;
end;
procedure getNoDeallocRegs(var regs: tregset);
var
regCounter: TSuperRegister;
begin
regs := [];
case current_procinfo.procdef.returndef.typ of
arraydef,recorddef,pointerdef,
stringdef,enumdef,procdef,objectdef,errordef,
filedef,setdef,procvardef,
classrefdef,forwarddef:
regs := [RS_EAX];
orddef:
if current_procinfo.procdef.returndef.size <> 0 then
begin
regs := [RS_EAX];
{ for int64/qword }
if current_procinfo.procdef.returndef.size = 8 then
regs := regs + [RS_EDX];
end;
end;
for regCounter := RS_EAX to RS_EBX do
{ if not(regCounter in rg.usableregsint) then}
include(regs,regcounter);
end;
procedure AddRegDeallocFor(asml: TAsmList; reg: tregister; p: tai);
var
hp1: tai;
funcResRegs: tregset;
{ funcResReg: boolean;}
begin
{ if not(supreg in rg.usableregsint) then
exit;}
{ if not(supreg in [RS_EDI]) then
exit;}
getNoDeallocRegs(funcresregs);
{ funcResRegs := funcResRegs - rg.usableregsint;}
{ funcResRegs := funcResRegs - [RS_EDI];}
{ funcResRegs := funcResRegs - [RS_EAX,RS_EBX,RS_ECX,RS_EDX,RS_ESI]; }
{ funcResReg := getsupreg(reg) in funcresregs;}
hp1 := p;
{
while not(funcResReg and
(p.typ = ait_instruction) and
(taicpu(p).opcode = A_JMP) and
(tasmlabel(taicpu(p).oper[0]^.sym) = aktexit2label)) and
getLastInstruction(p, p) and
not(regInInstruction(supreg, p)) do
hp1 := p;
}
{ don't insert a dealloc for registers which contain the function result }
{ if they are followed by a jump to the exit label (for exit(...)) }
{ if not(funcResReg) or
not((hp1.typ = ait_instruction) and
(taicpu(hp1).opcode = A_JMP) and
(tasmlabel(taicpu(hp1).oper[0]^.sym) = aktexit2label)) then }
begin
p := tai_regalloc.deAlloc(reg,nil);
insertLLItem(AsmL, hp1.previous, hp1, p);
end;
end;
{************************ Search the Label table ************************}
function findlabel(l: tasmlabel; var hp: tai): boolean;
{searches for the specified label starting from hp as long as the
encountered instructions are labels, to be able to optimize constructs like
jne l2 jmp l2
jmp l3 and l1:
l1: l2:
l2:}
var
p: tai;
begin
p := hp;
while assigned(p) and
(p.typ in SkipInstr + [ait_label,ait_align]) Do
if (p.typ <> ait_Label) or
(tai_label(p).labsym <> l) then
GetNextInstruction(p, p)
else
begin
hp := p;
findlabel := true;
exit
end;
findlabel := false;
end;
{************************ Some general functions ************************}
function tch2reg(ch: tinschange): tsuperregister;
{converts a TChange variable to a TRegister}
const
ch2reg: array[CH_REAX..CH_REDI] of tsuperregister = (RS_EAX,RS_ECX,RS_EDX,RS_EBX,RS_ESP,RS_EBP,RS_ESI,RS_EDI);
begin
if (ch <= CH_REDI) then
tch2reg := ch2reg[ch]
else if (ch <= CH_WEDI) then
tch2reg := ch2reg[tinschange(ord(ch) - ord(CH_REDI))]
else if (ch <= CH_RWEDI) then
tch2reg := ch2reg[tinschange(ord(ch) - ord(CH_WEDI))]
else if (ch <= CH_MEDI) then
tch2reg := ch2reg[tinschange(ord(ch) - ord(CH_RWEDI))]
else
InternalError($db)
end;
{ inserts new_one between prev and foll }
procedure InsertLLItem(AsmL: TAsmList; prev, foll, new_one: TLinkedListItem);
begin
if assigned(prev) then
if assigned(foll) then
begin
if assigned(new_one) then
begin
new_one.previous := prev;
new_one.next := foll;
prev.next := new_one;
foll.previous := new_one;
{ shgould we update line information }
if (not (tai(new_one).typ in SkipLineInfo)) and
(not (tai(foll).typ in SkipLineInfo)) then
tailineinfo(new_one).fileinfo := tailineinfo(foll).fileinfo;
end;
end
else
asml.Concat(new_one)
else
if assigned(foll) then
asml.Insert(new_one)
end;
{********************* Compare parts of tai objects *********************}
function regssamesize(reg1, reg2: tregister): boolean;
{returns true if Reg1 and Reg2 are of the same size (so if they're both
8bit, 16bit or 32bit)}
begin
if (reg1 = NR_NO) or (reg2 = NR_NO) then
internalerror(2003111602);
regssamesize := getsubreg(reg1) = getsubreg(reg2);
end;
procedure AddReg2RegInfo(OldReg, NewReg: TRegister; var RegInfo: toptreginfo);
{updates the ???RegsEncountered and ???2???reg fields of RegInfo. Assumes that
OldReg and NewReg have the same size (has to be chcked in advance with
RegsSameSize) and that neither equals RS_INVALID}
var
newsupreg, oldsupreg: tsuperregister;
begin
if (newreg = NR_NO) or (oldreg = NR_NO) then
internalerror(2003111601);
newsupreg := getsupreg(newreg);
oldsupreg := getsupreg(oldreg);
with RegInfo Do
begin
NewRegsEncountered := NewRegsEncountered + [newsupreg];
OldRegsEncountered := OldRegsEncountered + [oldsupreg];
New2OldReg[newsupreg] := oldsupreg;
end;
end;
procedure AddOp2RegInfo(const o:toper; var reginfo: toptreginfo);
begin
case o.typ Of
top_reg:
if (o.reg <> NR_NO) then
AddReg2RegInfo(o.reg, o.reg, RegInfo);
top_ref:
begin
if o.ref^.base <> NR_NO then
AddReg2RegInfo(o.ref^.base, o.ref^.base, RegInfo);
if o.ref^.index <> NR_NO then
AddReg2RegInfo(o.ref^.index, o.ref^.index, RegInfo);
end;
end;
end;
function RegsEquivalent(oldreg, newreg: tregister; const oldinst, newinst: taicpu; var reginfo: toptreginfo; opact: topaction): Boolean;
begin
if not((oldreg = NR_NO) or (newreg = NR_NO)) then
if RegsSameSize(oldreg, newreg) then
with reginfo do
{here we always check for the 32 bit component, because it is possible that
the 8 bit component has not been set, event though NewReg already has been
processed. This happens if it has been compared with a register that doesn't
have an 8 bit component (such as EDI). in that case the 8 bit component is
still set to RS_NO and the comparison in the else-part will fail}
if (getsupreg(oldReg) in OldRegsEncountered) then
if (getsupreg(NewReg) in NewRegsEncountered) then
RegsEquivalent := (getsupreg(oldreg) = New2OldReg[getsupreg(newreg)])
{ if we haven't encountered the new register yet, but we have encountered the
old one already, the new one can only be correct if it's being written to
(and consequently the old one is also being written to), otherwise
movl -8(%ebp), %eax and movl -8(%ebp), %eax
movl (%eax), %eax movl (%edx), %edx
are considered equivalent}
else
if (opact = opact_write) then
begin
AddReg2RegInfo(oldreg, newreg, reginfo);
RegsEquivalent := true
end
else
Regsequivalent := false
else
if not(getsupreg(newreg) in NewRegsEncountered) and
((opact = opact_write) or
((newreg = oldreg) and
(ptaiprop(oldinst.optinfo)^.regs[getsupreg(oldreg)].wstate =
ptaiprop(newinst.optinfo)^.regs[getsupreg(oldreg)].wstate) and
not(regmodifiedbyinstruction(getsupreg(oldreg),oldinst)))) then
begin
AddReg2RegInfo(oldreg, newreg, reginfo);
RegsEquivalent := true
end
else
RegsEquivalent := false
else
RegsEquivalent := false
else
RegsEquivalent := oldreg = newreg
end;
function RefsEquivalent(const r1, r2: treference; const oldinst, newinst: taicpu; var regInfo: toptreginfo): boolean;
begin
RefsEquivalent :=
(r1.offset = r2.offset) and
RegsEquivalent(r1.base, r2.base, oldinst, newinst, reginfo, OpAct_Read) and
RegsEquivalent(r1.index, r2.index, oldinst, newinst, reginfo, OpAct_Read) and
(r1.segment = r2.segment) and (r1.scalefactor = r2.scalefactor) and
(r1.symbol = r2.symbol) and (r1.refaddr = r2.refaddr) and
(r1.relsymbol = r2.relsymbol);
end;
function refsequal(const r1, r2: treference): boolean;
begin
refsequal :=
(r1.offset = r2.offset) and
(r1.segment = r2.segment) and (r1.base = r2.base) and
(r1.index = r2.index) and (r1.scalefactor = r2.scalefactor) and
(r1.symbol=r2.symbol) and (r1.refaddr = r2.refaddr) and
(r1.relsymbol = r2.relsymbol);
end;
{$ifdef q+}
{$q-}
{$define overflowon}
{$endif q+}
// checks whether a write to r2 of size "size" contains address r1
function refsoverlapping(const r1, r2: treference; size1, size2: tcgsize): boolean;
var
realsize1, realsize2: aint;
begin
realsize1 := tcgsize2size[size1];
realsize2 := tcgsize2size[size2];
refsoverlapping :=
(r2.offset <= r1.offset+realsize1) and
(r1.offset <= r2.offset+realsize2) and
(r1.segment = r2.segment) and (r1.base = r2.base) and
(r1.index = r2.index) and (r1.scalefactor = r2.scalefactor) and
(r1.symbol=r2.symbol) and (r1.refaddr = r2.refaddr) and
(r1.relsymbol = r2.relsymbol);
end;
{$ifdef overflowon}
{$q+}
{$undef overflowon}
{$endif overflowon}
function isgp32reg(supreg: tsuperregister): boolean;
{Checks if the register is a 32 bit general purpose register}
begin
isgp32reg := false;
if (supreg >= RS_EAX) and (supreg <= RS_EBX) then
isgp32reg := true
end;
function reginref(supreg: tsuperregister; const ref: treference): boolean;
begin {checks whether ref contains a reference to reg}
reginref :=
((ref.base <> NR_NO) and
(getsupreg(ref.base) = supreg)) or
((ref.index <> NR_NO) and
(getsupreg(ref.index) = supreg))
end;
function RegReadByInstruction(supreg: tsuperregister; hp: tai): boolean;
var
p: taicpu;
opcount: longint;
begin
RegReadByInstruction := false;
if hp.typ <> ait_instruction then
exit;
p := taicpu(hp);
case p.opcode of
A_CALL:
regreadbyinstruction := true;
A_IMUL:
case p.ops of
1:
regReadByInstruction :=
(supreg = RS_EAX) or reginop(supreg,p.oper[0]^);
2,3:
regReadByInstruction :=
reginop(supreg,p.oper[0]^) or
reginop(supreg,p.oper[1]^);
end;
A_IDIV,A_DIV,A_MUL:
begin
regReadByInstruction :=
reginop(supreg,p.oper[0]^) or (supreg in [RS_EAX,RS_EDX]);
end;
else
begin
for opcount := 0 to p.ops-1 do
if (p.oper[opCount]^.typ = top_ref) and
reginref(supreg,p.oper[opcount]^.ref^) then
begin
RegReadByInstruction := true;
exit
end;
for opcount := 1 to maxinschanges do
case insprop[p.opcode].ch[opcount] of
CH_REAX..CH_REDI,CH_RWEAX..CH_MEDI:
if supreg = tch2reg(insprop[p.opcode].ch[opcount]) then
begin
RegReadByInstruction := true;
exit
end;
CH_RWOP1,CH_ROP1,CH_MOP1:
if //(p.oper[0]^.typ = top_reg) and
reginop(supreg,p.oper[0]^) then
begin
RegReadByInstruction := true;
exit
end;
Ch_RWOP2,Ch_ROP2,Ch_MOP2:
if //(p.oper[1]^.typ = top_reg) and
reginop(supreg,p.oper[1]^) then
begin
RegReadByInstruction := true;
exit
end;
Ch_RWOP3,Ch_ROP3,Ch_MOP3:
if //(p.oper[2]^.typ = top_reg) and
reginop(supreg,p.oper[2]^) then
begin
RegReadByInstruction := true;
exit
end;
end;
end;
end;
end;
function regInInstruction(supreg: tsuperregister; p1: tai): boolean;
{ Checks if reg is used by the instruction p1 }
{ Difference with "regReadBysinstruction() or regModifiedByInstruction()": }
{ this one ignores CH_ALL opcodes, while regModifiedByInstruction doesn't }
var
p: taicpu;
opcount: longint;
begin
regInInstruction := false;
if p1.typ <> ait_instruction then
exit;
p := taicpu(p1);
case p.opcode of
A_CALL:
regininstruction := true;
A_IMUL:
case p.ops of
1:
regInInstruction :=
(supreg = RS_EAX) or reginop(supreg,p.oper[0]^);
2,3:
regInInstruction :=
reginop(supreg,p.oper[0]^) or
reginop(supreg,p.oper[1]^) or
(assigned(p.oper[2]) and
reginop(supreg,p.oper[2]^));
end;
A_IDIV,A_DIV,A_MUL:
regInInstruction :=
reginop(supreg,p.oper[0]^) or
(supreg in [RS_EAX,RS_EDX])
else
begin
for opcount := 0 to p.ops-1 do
if (p.oper[opCount]^.typ = top_ref) and
reginref(supreg,p.oper[opcount]^.ref^) then
begin
regInInstruction := true;
exit
end;
for opcount := 1 to maxinschanges do
case insprop[p.opcode].Ch[opCount] of
CH_REAX..CH_MEDI:
if tch2reg(InsProp[p.opcode].Ch[opCount]) = supreg then
begin
regInInstruction := true;
exit;
end;
CH_ROp1..CH_MOp1:
if reginop(supreg,p.oper[0]^) then
begin
regInInstruction := true;
exit
end;
Ch_ROp2..Ch_MOp2:
if reginop(supreg,p.oper[1]^) then
begin
regInInstruction := true;
exit
end;
Ch_ROp3..Ch_MOp3:
if reginop(supreg,p.oper[2]^) then
begin
regInInstruction := true;
exit
end;
end;
end;
end;
end;
function reginop(supreg: tsuperregister; const o:toper): boolean;
begin
reginop := false;
case o.typ Of
top_reg:
reginop :=
(getregtype(o.reg) = R_INTREGISTER) and
(supreg = getsupreg(o.reg));
top_ref:
reginop :=
((o.ref^.base <> NR_NO) and
(supreg = getsupreg(o.ref^.base))) or
((o.ref^.index <> NR_NO) and
(supreg = getsupreg(o.ref^.index)));
end;
end;
function RegModifiedByInstruction(supreg: tsuperregister; p1: tai): boolean;
var
InstrProp: TInsProp;
TmpResult: Boolean;
Cnt: Word;
begin
TmpResult := False;
if supreg = RS_INVALID then
exit;
if (p1.typ = ait_instruction) then
case taicpu(p1).opcode of
A_IMUL:
With taicpu(p1) Do
TmpResult :=
((ops = 1) and (supreg in [RS_EAX,RS_EDX])) or
((ops = 2) and (getsupreg(oper[1]^.reg) = supreg)) or
((ops = 3) and (getsupreg(oper[2]^.reg) = supreg));
A_DIV, A_IDIV, A_MUL:
With taicpu(p1) Do
TmpResult :=
(supreg in [RS_EAX,RS_EDX]);
else
begin
Cnt := 1;
InstrProp := InsProp[taicpu(p1).OpCode];
while (Cnt <= maxinschanges) and
(InstrProp.Ch[Cnt] <> Ch_None) and
not(TmpResult) Do
begin
case InstrProp.Ch[Cnt] Of
Ch_WEAX..Ch_MEDI:
TmpResult := supreg = tch2reg(InstrProp.Ch[Cnt]);
Ch_RWOp1,Ch_WOp1,Ch_Mop1:
TmpResult := (taicpu(p1).oper[0]^.typ = top_reg) and
reginop(supreg,taicpu(p1).oper[0]^);
Ch_RWOp2,Ch_WOp2,Ch_Mop2:
TmpResult := (taicpu(p1).oper[1]^.typ = top_reg) and
reginop(supreg,taicpu(p1).oper[1]^);
Ch_RWOp3,Ch_WOp3,Ch_Mop3:
TmpResult := (taicpu(p1).oper[2]^.typ = top_reg) and
reginop(supreg,taicpu(p1).oper[2]^);
Ch_FPU: TmpResult := false; // supreg is supposed to be an intreg!! supreg in [RS_ST..RS_ST7,RS_MM0..RS_MM7];
Ch_ALL: TmpResult := true;
end;
inc(Cnt)
end
end
end;
RegModifiedByInstruction := TmpResult
end;
function instrWritesFlags(p: tai): boolean;
var
l: longint;
begin
instrWritesFlags := true;
case p.typ of
ait_instruction:
begin
for l := 1 to maxinschanges do
if InsProp[taicpu(p).opcode].Ch[l] in [Ch_WFlags,Ch_RWFlags,Ch_All] then
exit;
end;
ait_label:
exit;
end;
instrWritesFlags := false;
end;
function instrReadsFlags(p: tai): boolean;
var
l: longint;
begin
instrReadsFlags := true;
case p.typ of
ait_instruction:
begin
for l := 1 to maxinschanges do
if InsProp[taicpu(p).opcode].Ch[l] in [Ch_RFlags,Ch_RWFlags,Ch_All] then
exit;
end;
ait_label:
exit;
end;
instrReadsFlags := false;
end;
{********************* GetNext and GetLastInstruction *********************}
function GetNextInstruction(Current: tai; var Next: tai): Boolean;
{ skips ait_regalloc, ait_regdealloc and ait_stab* objects and puts the }
{ next tai object in Next. Returns false if there isn't any }
begin
repeat
if (Current.typ = ait_marker) and
(tai_Marker(current).Kind = mark_AsmBlockStart) then
begin
GetNextInstruction := False;
Next := Nil;
Exit
end;
Current := tai(current.Next);
while assigned(Current) and
((current.typ in skipInstr) or
((current.typ = ait_label) and
labelCanBeSkipped(tai_label(current)))) do
Current := tai(current.Next);
{ if assigned(Current) and
(current.typ = ait_Marker) and
(tai_Marker(current).Kind = mark_NoPropInfoStart) then
begin
while assigned(Current) and
((current.typ <> ait_Marker) or
(tai_Marker(current).Kind <> mark_NoPropInfoEnd)) Do
Current := tai(current.Next);
end;}
until not(assigned(Current)) or
(current.typ <> ait_Marker) or
not(tai_Marker(current).Kind in [mark_NoPropInfoStart,mark_NoPropInfoEnd]);
Next := Current;
if assigned(Current) and
not((current.typ in SkipInstr) or
((current.typ = ait_label) and
labelCanBeSkipped(tai_label(current))))
then
GetNextInstruction :=
not((current.typ = ait_marker) and
(tai_marker(current).kind = mark_AsmBlockStart))
else
begin
GetNextInstruction := False;
Next := nil;
end;
end;
function GetLastInstruction(Current: tai; var Last: tai): boolean;
{skips the ait-types in SkipInstr puts the previous tai object in
Last. Returns false if there isn't any}
begin
repeat
Current := tai(current.previous);
while assigned(Current) and
(((current.typ = ait_Marker) and
not(tai_Marker(current).Kind in [mark_AsmBlockEnd{,mark_NoPropInfoEnd}])) or
(current.typ in SkipInstr) or
((current.typ = ait_label) and
labelCanBeSkipped(tai_label(current)))) Do
Current := tai(current.previous);
{ if assigned(Current) and
(current.typ = ait_Marker) and
(tai_Marker(current).Kind = mark_NoPropInfoEnd) then
begin
while assigned(Current) and
((current.typ <> ait_Marker) or
(tai_Marker(current).Kind <> mark_NoPropInfoStart)) Do
Current := tai(current.previous);
end;}
until not(assigned(Current)) or
(current.typ <> ait_Marker) or
not(tai_Marker(current).Kind in [mark_NoPropInfoStart,mark_NoPropInfoEnd]);
if not(assigned(Current)) or
(current.typ in SkipInstr) or
((current.typ = ait_label) and
labelCanBeSkipped(tai_label(current))) or
((current.typ = ait_Marker) and
(tai_Marker(current).Kind = mark_AsmBlockEnd))
then
begin
Last := nil;
GetLastInstruction := False
end
else
begin
Last := Current;
GetLastInstruction := True;
end;
end;
procedure SkipHead(var p: tai);
var
oldp: tai;
begin
repeat
oldp := p;
if (p.typ in SkipInstr) or
((p.typ = ait_marker) and
(tai_Marker(p).Kind in [mark_AsmBlockEnd,mark_InlineStart,mark_InlineEnd])) then
GetNextInstruction(p,p)
else if ((p.Typ = Ait_Marker) and
(tai_Marker(p).Kind = mark_NoPropInfoStart)) then
{a marker of the mark_NoPropInfoStart can't be the first instruction of a
TAsmList list}
GetNextInstruction(tai(p.previous),p);
until p = oldp
end;
function labelCanBeSkipped(p: tai_label): boolean;
begin
labelCanBeSkipped := not(p.labsym.is_used) or (p.labsym.labeltype<>alt_jump);
end;
{******************* The Data Flow Analyzer functions ********************}
function regLoadedWithNewValue(supreg: tsuperregister; canDependOnPrevValue: boolean;
hp: tai): boolean;
{ assumes reg is a 32bit register }
var
p: taicpu;
begin
if not assigned(hp) or
(hp.typ <> ait_instruction) then
begin
regLoadedWithNewValue := false;
exit;
end;
p := taicpu(hp);
regLoadedWithNewValue :=
(((p.opcode = A_MOV) or
(p.opcode = A_MOVZX) or
(p.opcode = A_MOVSX) or
(p.opcode = A_LEA)) and
(p.oper[1]^.typ = top_reg) and
(getsupreg(p.oper[1]^.reg) = supreg) and
(canDependOnPrevValue or
(p.oper[0]^.typ = top_const) or
((p.oper[0]^.typ = top_reg) and
(getsupreg(p.oper[0]^.reg) <> supreg)) or
((p.oper[0]^.typ = top_ref) and
not regInRef(supreg,p.oper[0]^.ref^)))) or
((p.opcode = A_POP) and
(getsupreg(p.oper[0]^.reg) = supreg));
end;
procedure UpdateUsedRegs(var UsedRegs: TRegSet; p: tai);
{updates UsedRegs with the RegAlloc Information coming after p}
begin
repeat
while assigned(p) and
((p.typ in (SkipInstr - [ait_RegAlloc])) or
((p.typ = ait_label) and
labelCanBeSkipped(tai_label(p))) or
((p.typ = ait_marker) and
(tai_Marker(p).Kind in [mark_AsmBlockEnd,mark_InlineStart,mark_InlineEnd]))) do
p := tai(p.next);
while assigned(p) and
(p.typ=ait_RegAlloc) Do
begin
if (getregtype(tai_regalloc(p).reg) = R_INTREGISTER) then
begin
case tai_regalloc(p).ratype of
ra_alloc :
Include(UsedRegs, TRegEnum(getsupreg(tai_regalloc(p).reg)));
ra_dealloc :
Exclude(UsedRegs, TRegEnum(getsupreg(tai_regalloc(p).reg)));
end;
end;
p := tai(p.next);
end;
until not(assigned(p)) or
(not(p.typ in SkipInstr) and
not((p.typ = ait_label) and
labelCanBeSkipped(tai_label(p))));
end;
procedure AllocRegBetween(asml: TAsmList; reg: tregister; p1, p2: tai; var initialusedregs: tregset);
{ allocates register reg between (and including) instructions p1 and p2 }
{ the type of p1 and p2 must not be in SkipInstr }
{ note that this routine is both called from the peephole optimizer }
{ where optinfo is not yet initialised) and from the cse (where it is) }
var
hp, start: tai;
removedsomething,
firstRemovedWasAlloc,
lastRemovedWasDealloc: boolean;
supreg: tsuperregister;
begin
{$ifdef EXTDEBUG}
if assigned(p1.optinfo) and
(ptaiprop(p1.optinfo)^.usedregs <> initialusedregs) then
internalerror(2004101010);
{$endif EXTDEBUG}
start := p1;
if (reg = NR_ESP) or
(reg = current_procinfo.framepointer) or
not(assigned(p1)) then
{ this happens with registers which are loaded implicitely, outside the }
{ current block (e.g. esi with self) }
exit;
supreg := getsupreg(reg);
{ make sure we allocate it for this instruction }
getnextinstruction(p2,p2);
lastRemovedWasDealloc := false;
removedSomething := false;
firstRemovedWasAlloc := false;
{$ifdef allocregdebug}
hp := tai_comment.Create(strpnew('allocating '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+
' from here...'));
insertllitem(asml,p1.previous,p1,hp);
hp := tai_comment.Create(strpnew('allocated '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+
' till here...'));
insertllitem(asml,p2,p2.next,hp);
{$endif allocregdebug}
if not(supreg in initialusedregs) then
begin
hp := tai_regalloc.alloc(reg,nil);
insertllItem(asmL,p1.previous,p1,hp);
include(initialusedregs,supreg);
end;
while assigned(p1) and
(p1 <> p2) do
begin
if assigned(p1.optinfo) then
include(ptaiprop(p1.optinfo)^.usedregs,supreg);
p1 := tai(p1.next);
repeat
while assigned(p1) and
(p1.typ in (SkipInstr-[ait_regalloc])) Do
p1 := tai(p1.next);
{ remove all allocation/deallocation info about the register in between }
if assigned(p1) and
(p1.typ = ait_regalloc) then
if (getsupreg(tai_regalloc(p1).reg) = supreg) then
begin
if not removedSomething then
begin
firstRemovedWasAlloc := tai_regalloc(p1).ratype=ra_alloc;
removedSomething := true;
end;
lastRemovedWasDealloc := (tai_regalloc(p1).ratype=ra_dealloc);
hp := tai(p1.Next);
asml.Remove(p1);
p1.free;
p1 := hp;
end
else p1 := tai(p1.next);
until not(assigned(p1)) or
not(p1.typ in SkipInstr);
end;
if assigned(p1) then
begin
if firstRemovedWasAlloc then
begin
hp := tai_regalloc.Alloc(reg,nil);
insertLLItem(asmL,start.previous,start,hp);
end;
if lastRemovedWasDealloc then
begin
hp := tai_regalloc.DeAlloc(reg,nil);
insertLLItem(asmL,p1.previous,p1,hp);
end;
end;
end;
function FindRegDealloc(supreg: tsuperregister; p: tai): boolean;
var
hp: tai;
first: boolean;
begin
findregdealloc := false;
first := true;
while assigned(p.previous) and
((tai(p.previous).typ in (skipinstr+[ait_align])) or
((tai(p.previous).typ = ait_label) and
labelCanBeSkipped(tai_label(p.previous)))) do
begin
p := tai(p.previous);
if (p.typ = ait_regalloc) and
(getregtype(tai_regalloc(p).reg) = R_INTREGISTER) and
(getsupreg(tai_regalloc(p).reg) = supreg) then
if (tai_regalloc(p).ratype=ra_dealloc) then
if first then
begin
findregdealloc := true;
break;
end
else
begin
findRegDealloc :=
getNextInstruction(p,hp) and
regLoadedWithNewValue(supreg,false,hp);
break
end
else
first := false;
end
end;
procedure incState(var S: Byte; amount: longint);
{increases S by 1, wraps around at $ffff to 0 (so we won't get overflow
errors}
begin
if (s <= $ff - amount) then
inc(s, amount)
else s := longint(s) + amount - $ff;
end;
function sequenceDependsonReg(const Content: TContent; seqreg: tsuperregister; supreg: tsuperregister): Boolean;
{ Content is the sequence of instructions that describes the contents of }
{ seqReg. reg is being overwritten by the current instruction. if the }
{ content of seqReg depends on reg (ie. because of a }
{ "movl (seqreg,reg), seqReg" instruction), this function returns true }
var
p: tai;
Counter: Word;
TmpResult: Boolean;
RegsChecked: TRegSet;
begin
RegsChecked := [];
p := Content.StartMod;
TmpResult := False;
Counter := 1;
while not(TmpResult) and
(Counter <= Content.NrOfMods) Do
begin
if (p.typ = ait_instruction) and
((taicpu(p).opcode = A_MOV) or
(taicpu(p).opcode = A_MOVZX) or
(taicpu(p).opcode = A_MOVSX) or
(taicpu(p).opcode = A_LEA)) and
(taicpu(p).oper[0]^.typ = top_ref) then
With taicpu(p).oper[0]^.ref^ Do
if ((base = current_procinfo.FramePointer) or
(assigned(symbol) and (base = NR_NO))) and
(index = NR_NO) then
begin
RegsChecked := RegsChecked + [getsupreg(taicpu(p).oper[1]^.reg)];
if supreg = getsupreg(taicpu(p).oper[1]^.reg) then
break;
end
else
tmpResult :=
regReadByInstruction(supreg,p) and
regModifiedByInstruction(seqReg,p)
else
tmpResult :=
regReadByInstruction(supreg,p) and
regModifiedByInstruction(seqReg,p);
inc(Counter);
GetNextInstruction(p,p)
end;
sequenceDependsonReg := TmpResult
end;
procedure invalidateDependingRegs(p1: ptaiprop; supreg: tsuperregister);
var
counter: tsuperregister;
begin
for counter := RS_EAX to RS_EDI do
if counter <> supreg then
with p1^.regs[counter] Do
begin
if (typ in [con_ref,con_noRemoveRef]) and
sequenceDependsOnReg(p1^.Regs[counter],counter,supreg) then
if typ in [con_ref, con_invalid] then
typ := con_invalid
{ con_noRemoveRef = con_unknown }
else
typ := con_unknown;
if assigned(memwrite) and
regInRef(counter,memwrite.oper[1]^.ref^) then
memwrite := nil;
end;
end;
procedure DestroyReg(p1: ptaiprop; supreg: tsuperregister; doincState:Boolean);
{Destroys the contents of the register reg in the ptaiprop p1, as well as the
contents of registers are loaded with a memory location based on reg.
doincState is false when this register has to be destroyed not because
it's contents are directly modified/overwritten, but because of an indirect
action (e.g. this register holds the contents of a variable and the value
of the variable in memory is changed) }
begin
{ the following happens for fpu registers }
if (supreg < low(NrOfInstrSinceLastMod)) or
(supreg > high(NrOfInstrSinceLastMod)) then
exit;
NrOfInstrSinceLastMod[supreg] := 0;
with p1^.regs[supreg] do
begin
if doincState then
begin
incState(wstate,1);
typ := con_unknown;
startmod := nil;
end
else
if typ in [con_ref,con_const,con_invalid] then
typ := con_invalid
{ con_noRemoveRef = con_unknown }
else
typ := con_unknown;
memwrite := nil;
end;
invalidateDependingRegs(p1,supreg);
end;
{procedure AddRegsToSet(p: tai; var RegSet: TRegSet);
begin
if (p.typ = ait_instruction) then
begin
case taicpu(p).oper[0]^.typ Of
top_reg:
if not(taicpu(p).oper[0]^.reg in [RS_NO,RS_ESP,current_procinfo.FramePointer]) then
RegSet := RegSet + [taicpu(p).oper[0]^.reg];
top_ref:
With TReference(taicpu(p).oper[0]^) Do
begin
if not(base in [current_procinfo.FramePointer,RS_NO,RS_ESP])
then RegSet := RegSet + [base];
if not(index in [current_procinfo.FramePointer,RS_NO,RS_ESP])
then RegSet := RegSet + [index];
end;
end;
case taicpu(p).oper[1]^.typ Of
top_reg:
if not(taicpu(p).oper[1]^.reg in [RS_NO,RS_ESP,current_procinfo.FramePointer]) then
if RegSet := RegSet + [TRegister(TwoWords(taicpu(p).oper[1]^).Word1];
top_ref:
With TReference(taicpu(p).oper[1]^) Do
begin
if not(base in [current_procinfo.FramePointer,RS_NO,RS_ESP])
then RegSet := RegSet + [base];
if not(index in [current_procinfo.FramePointer,RS_NO,RS_ESP])
then RegSet := RegSet + [index];
end;
end;
end;
end;}
function OpsEquivalent(const o1, o2: toper; const oldinst, newinst: taicpu; var RegInfo: toptreginfo; OpAct: TopAction): Boolean;
begin {checks whether the two ops are equivalent}
OpsEquivalent := False;
if o1.typ=o2.typ then
case o1.typ Of
top_reg:
OpsEquivalent :=RegsEquivalent(o1.reg,o2.reg, oldinst, newinst, RegInfo, OpAct);
top_ref:
OpsEquivalent := RefsEquivalent(o1.ref^, o2.ref^, oldinst, newinst, RegInfo);
Top_Const:
OpsEquivalent := o1.val = o2.val;
Top_None:
OpsEquivalent := True
end;
end;
function OpsEqual(const o1,o2:toper): Boolean;
begin {checks whether the two ops are equal}
OpsEqual := False;
if o1.typ=o2.typ then
case o1.typ Of
top_reg :
OpsEqual:=o1.reg=o2.reg;
top_ref :
OpsEqual := RefsEqual(o1.ref^, o2.ref^);
Top_Const :
OpsEqual:=o1.val=o2.val;
Top_None :
OpsEqual := True
end;
end;
function sizescompatible(loadsize,newsize: topsize): boolean;
begin
case loadsize of
S_B,S_BW,S_BL:
sizescompatible := (newsize = loadsize) or (newsize = S_B);
S_W,S_WL:
sizescompatible := (newsize = loadsize) or (newsize = S_W);
else
sizescompatible := newsize = S_L;
end;
end;
function opscompatible(p1,p2: taicpu): boolean;
begin
case p1.opcode of
A_MOVZX,A_MOVSX:
opscompatible :=
((p2.opcode = p1.opcode) or (p2.opcode = A_MOV)) and
sizescompatible(p1.opsize,p2.opsize);
else
opscompatible :=
(p1.opcode = p2.opcode) and
(p1.ops = p2.ops) and
(p1.opsize = p2.opsize);
end;
end;
function InstructionsEquivalent(p1, p2: tai; var RegInfo: toptreginfo): Boolean;
{$ifdef csdebug}
var
hp: tai;
{$endif csdebug}
begin {checks whether two taicpu instructions are equal}
if assigned(p1) and assigned(p2) and
(tai(p1).typ = ait_instruction) and
(tai(p2).typ = ait_instruction) and
opscompatible(taicpu(p1),taicpu(p2)) and
(not(assigned(taicpu(p1).oper[0])) or
(taicpu(p1).oper[0]^.typ = taicpu(p2).oper[0]^.typ)) and
(not(assigned(taicpu(p1).oper[1])) or
(taicpu(p1).oper[1]^.typ = taicpu(p2).oper[1]^.typ)) and
(not(assigned(taicpu(p1).oper[2])) or
(taicpu(p1).oper[2]^.typ = taicpu(p2).oper[2]^.typ)) then
{both instructions have the same structure:
"<operator> <operand of type1>, <operand of type 2>"}
if ((taicpu(p1).opcode = A_MOV) or
(taicpu(p1).opcode = A_MOVZX) or
(taicpu(p1).opcode = A_MOVSX) or
(taicpu(p1).opcode = A_LEA)) and
(taicpu(p1).oper[0]^.typ = top_ref) {then .oper[1]^t = top_reg} then
if not(RegInRef(getsupreg(taicpu(p1).oper[1]^.reg), taicpu(p1).oper[0]^.ref^)) then
{the "old" instruction is a load of a register with a new value, not with
a value based on the contents of this register (so no "mov (reg), reg")}
if not(RegInRef(getsupreg(taicpu(p2).oper[1]^.reg), taicpu(p2).oper[0]^.ref^)) and
RefsEquivalent(taicpu(p1).oper[0]^.ref^, taicpu(p2).oper[0]^.ref^,taicpu(p1), taicpu(p2), reginfo) then
{the "new" instruction is also a load of a register with a new value, and
this value is fetched from the same memory location}
begin
With taicpu(p2).oper[0]^.ref^ Do
begin
if (base <> NR_NO) and
(not(getsupreg(base) in [getsupreg(current_procinfo.FramePointer), RS_ESP])) then
include(RegInfo.RegsLoadedForRef, getsupreg(base));
if (index <> NR_NO) and
(not(getsupreg(index) in [getsupreg(current_procinfo.FramePointer), RS_ESP])) then
include(RegInfo.RegsLoadedForRef, getsupreg(index));
end;
{add the registers from the reference (.oper[0]^) to the RegInfo, all registers
from the reference are the same in the old and in the new instruction
sequence}
AddOp2RegInfo(taicpu(p1).oper[0]^, RegInfo);
{the registers from .oper[1]^ have to be equivalent, but not necessarily equal}
InstructionsEquivalent :=
RegsEquivalent(taicpu(p1).oper[1]^.reg,
taicpu(p2).oper[1]^.reg, taicpu(p1), taicpu(p2), RegInfo, OpAct_Write);
end
{the registers are loaded with values from different memory locations. if
this was allowed, the instructions "mov -4(esi),eax" and "mov -4(ebp),eax"
would be considered equivalent}
else
InstructionsEquivalent := False
else
{load register with a value based on the current value of this register}
begin
With taicpu(p2).oper[0]^.ref^ Do
begin
if (base <> NR_NO) and
(not(getsupreg(base) in [getsupreg(current_procinfo.FramePointer),
getsupreg(taicpu(p2).oper[1]^.reg),RS_ESP])) then
{it won't do any harm if the register is already in RegsLoadedForRef}
begin
include(RegInfo.RegsLoadedForRef, getsupreg(base));
{$ifdef csdebug}
Writeln(std_regname(base), ' added');
{$endif csdebug}
end;
if (index <> NR_NO) and
(not(getsupreg(index) in [getsupreg(current_procinfo.FramePointer),
getsupreg(taicpu(p2).oper[1]^.reg),RS_ESP])) then
begin
include(RegInfo.RegsLoadedForRef, getsupreg(index));
{$ifdef csdebug}
Writeln(std_regname(index), ' added');
{$endif csdebug}
end;
end;
if (taicpu(p2).oper[1]^.reg <> NR_NO) and
(not(getsupreg(taicpu(p2).oper[1]^.reg) in [getsupreg(current_procinfo.FramePointer),RS_ESP])) then
begin
RegInfo.RegsLoadedForRef := RegInfo.RegsLoadedForRef -
[getsupreg(taicpu(p2).oper[1]^.reg)];
{$ifdef csdebug}
Writeln(std_regname(newreg(R_INTREGISTER,getsupreg(taicpu(p2).oper[1]^.reg),R_SUBWHOLE)), ' removed');
{$endif csdebug}
end;
InstructionsEquivalent :=
OpsEquivalent(taicpu(p1).oper[0]^, taicpu(p2).oper[0]^, taicpu(p1), taicpu(p2), RegInfo, OpAct_Read) and
OpsEquivalent(taicpu(p1).oper[1]^, taicpu(p2).oper[1]^, taicpu(p1), taicpu(p2), RegInfo, OpAct_Write)
end
else
{an instruction <> mov, movzx, movsx}
begin
{$ifdef csdebug}
hp := tai_comment.Create(strpnew('checking if equivalent'));
hp.previous := p2;
hp.next := p2.next;
p2.next.previous := hp;
p2.next := hp;
{$endif csdebug}
InstructionsEquivalent :=
(not(assigned(taicpu(p1).oper[0])) or
OpsEquivalent(taicpu(p1).oper[0]^, taicpu(p2).oper[0]^, taicpu(p1), taicpu(p2), RegInfo, OpAct_Unknown)) and
(not(assigned(taicpu(p1).oper[1])) or
OpsEquivalent(taicpu(p1).oper[1]^, taicpu(p2).oper[1]^, taicpu(p1), taicpu(p2), RegInfo, OpAct_Unknown)) and
(not(assigned(taicpu(p1).oper[2])) or
OpsEquivalent(taicpu(p1).oper[2]^, taicpu(p2).oper[2]^, taicpu(p1), taicpu(p2), RegInfo, OpAct_Unknown))
end
{the instructions haven't even got the same structure, so they're certainly
not equivalent}
else
begin
{$ifdef csdebug}
hp := tai_comment.Create(strpnew('different opcodes/format'));
hp.previous := p2;
hp.next := p2.next;
p2.next.previous := hp;
p2.next := hp;
{$endif csdebug}
InstructionsEquivalent := False;
end;
{$ifdef csdebug}
hp := tai_comment.Create(strpnew('instreq: '+tostr(byte(instructionsequivalent))));
hp.previous := p2;
hp.next := p2.next;
p2.next.previous := hp;
p2.next := hp;
{$endif csdebug}
end;
(*
function InstructionsEqual(p1, p2: tai): Boolean;
begin {checks whether two taicpu instructions are equal}
InstructionsEqual :=
assigned(p1) and assigned(p2) and
((tai(p1).typ = ait_instruction) and
(tai(p1).typ = ait_instruction) and
(taicpu(p1).opcode = taicpu(p2).opcode) and
(taicpu(p1).oper[0]^.typ = taicpu(p2).oper[0]^.typ) and
(taicpu(p1).oper[1]^.typ = taicpu(p2).oper[1]^.typ) and
OpsEqual(taicpu(p1).oper[0]^.typ, taicpu(p1).oper[0]^, taicpu(p2).oper[0]^) and
OpsEqual(taicpu(p1).oper[1]^.typ, taicpu(p1).oper[1]^, taicpu(p2).oper[1]^))
end;
*)
procedure readreg(p: ptaiprop; supreg: tsuperregister);
begin
if supreg in [RS_EAX..RS_EDI] then
incState(p^.regs[supreg].rstate,1)
end;
procedure readref(p: ptaiprop; const ref: preference);
begin
if ref^.base <> NR_NO then
readreg(p, getsupreg(ref^.base));
if ref^.index <> NR_NO then
readreg(p, getsupreg(ref^.index));
end;
procedure ReadOp(p: ptaiprop;const o:toper);
begin
case o.typ Of
top_reg: readreg(p, getsupreg(o.reg));
top_ref: readref(p, o.ref);
end;
end;
function RefInInstruction(const ref: TReference; p: tai;
RefsEq: TRefCompare; size: tcgsize): Boolean;
{checks whehter ref is used in p}
var
mysize: tcgsize;
TmpResult: Boolean;
begin
TmpResult := False;
if (p.typ = ait_instruction) then
begin
mysize := topsize2tcgsize[taicpu(p).opsize];
if (taicpu(p).ops >= 1) and
(taicpu(p).oper[0]^.typ = top_ref) then
TmpResult := RefsEq(taicpu(p).oper[0]^.ref^,ref,mysize,size);
if not(TmpResult) and
(taicpu(p).ops >= 2) and
(taicpu(p).oper[1]^.typ = top_ref) then
TmpResult := RefsEq(taicpu(p).oper[1]^.ref^,ref,mysize,size);
if not(TmpResult) and
(taicpu(p).ops >= 3) and
(taicpu(p).oper[2]^.typ = top_ref) then
TmpResult := RefsEq(taicpu(p).oper[2]^.ref^,ref,mysize,size);
end;
RefInInstruction := TmpResult;
end;
function RefInSequence(const ref: TReference; Content: TContent;
RefsEq: TRefCompare; size: tcgsize): Boolean;
{checks the whole sequence of Content (so StartMod and and the next NrOfMods
tai objects) to see whether ref is used somewhere}
var p: tai;
Counter: Word;
TmpResult: Boolean;
begin
p := Content.StartMod;
TmpResult := False;
Counter := 1;
while not(TmpResult) and
(Counter <= Content.NrOfMods) Do
begin
if (p.typ = ait_instruction) and
RefInInstruction(ref, p, RefsEq, size)
then TmpResult := True;
inc(Counter);
GetNextInstruction(p,p)
end;
RefInSequence := TmpResult
end;
{$ifdef q+}
{$q-}
{$define overflowon}
{$endif q+}
// checks whether a write to r2 of size "size" contains address r1
function arrayrefsoverlapping(const r1, r2: treference; size1, size2: tcgsize): Boolean;
var
realsize1, realsize2: aint;
begin
realsize1 := tcgsize2size[size1];
realsize2 := tcgsize2size[size2];
arrayrefsoverlapping :=
(r2.offset <= r1.offset+realsize1) and
(r1.offset <= r2.offset+realsize2) and
(r1.segment = r2.segment) and
(r1.symbol=r2.symbol) and
(r1.base = r2.base)
end;
{$ifdef overflowon}
{$q+}
{$undef overflowon}
{$endif overflowon}
function isSimpleRef(const ref: treference): boolean;
{ returns true if ref is reference to a local or global variable, to a }
{ parameter or to an object field (this includes arrays). Returns false }
{ otherwise. }
begin
isSimpleRef :=
assigned(ref.symbol) or
(ref.base = current_procinfo.framepointer);
end;
function containsPointerRef(p: tai): boolean;
{ checks if an instruction contains a reference which is a pointer location }
var
hp: taicpu;
count: longint;
begin
containsPointerRef := false;
if p.typ <> ait_instruction then
exit;
hp := taicpu(p);
for count := 0 to hp.ops-1 do
begin
case hp.oper[count]^.typ of
top_ref:
if not isSimpleRef(hp.oper[count]^.ref^) then
begin
containsPointerRef := true;
exit;
end;
top_none:
exit;
end;
end;
end;
function containsPointerLoad(c: tcontent): boolean;
{ checks whether the contents of a register contain a pointer reference }
var
p: tai;
count: longint;
begin
containsPointerLoad := false;
p := c.startmod;
for count := c.nrOfMods downto 1 do
begin
if containsPointerRef(p) then
begin
containsPointerLoad := true;
exit;
end;
getnextinstruction(p,p);
end;
end;
function writeToMemDestroysContents(regWritten: tsuperregister; const ref: treference;
supreg: tsuperregister; size: tcgsize; const c: tcontent; var invalsmemwrite: boolean): boolean;
{ returns whether the contents c of reg are invalid after regWritten is }
{ is written to ref }
var
refsEq: trefCompare;
begin
if isSimpleRef(ref) then
begin
if (ref.index <> NR_NO) or
(assigned(ref.symbol) and
(ref.base <> NR_NO)) then
{ local/global variable or parameter which is an array }
refsEq := @arrayRefsOverlapping
else
{ local/global variable or parameter which is not an array }
refsEq := @refsOverlapping;
invalsmemwrite :=
assigned(c.memwrite) and
((not(cs_opt_size in current_settings.optimizerswitches) and
containsPointerRef(c.memwrite)) or
refsEq(c.memwrite.oper[1]^.ref^,ref,topsize2tcgsize[c.memwrite.opsize],size));
if not(c.typ in [con_ref,con_noRemoveRef,con_invalid]) then
begin
writeToMemDestroysContents := false;
exit;
end;
{ write something to a parameter, a local or global variable, so }
{ * with uncertain optimizations on: }
{ - destroy the contents of registers whose contents have somewhere a }
{ "mov?? (ref), %reg". WhichReg (this is the register whose contents }
{ are being written to memory) is not destroyed if it's StartMod is }
{ of that form and NrOfMods = 1 (so if it holds ref, but is not a }
{ expression based on ref) }
{ * with uncertain optimizations off: }
{ - also destroy registers that contain any pointer }
with c do
writeToMemDestroysContents :=
(typ in [con_ref,con_noRemoveRef]) and
((not(cs_opt_size in current_settings.optimizerswitches) and
containsPointerLoad(c)
) or
(refInSequence(ref,c,refsEq,size) and
((supreg <> regWritten) or
not((nrOfMods = 1) and
{StarMod is always of the type ait_instruction}
(taicpu(StartMod).oper[0]^.typ = top_ref) and
refsEq(taicpu(StartMod).oper[0]^.ref^, ref, topsize2tcgsize[taicpu(StartMod).opsize],size)
)
)
)
);
end
else
{ write something to a pointer location, so }
{ * with uncertain optimzations on: }
{ - do not destroy registers which contain a local/global variable or }
{ a parameter, except if DestroyRefs is called because of a "movsl" }
{ * with uncertain optimzations off: }
{ - destroy every register which contains a memory location }
begin
invalsmemwrite :=
assigned(c.memwrite) and
(not(cs_opt_size in current_settings.optimizerswitches) or
containsPointerRef(c.memwrite));
if not(c.typ in [con_ref,con_noRemoveRef,con_invalid]) then
begin
writeToMemDestroysContents := false;
exit;
end;
with c do
writeToMemDestroysContents :=
(typ in [con_ref,con_noRemoveRef]) and
(not(cs_opt_size in current_settings.optimizerswitches) or
{ for movsl }
((ref.base = NR_EDI) and (ref.index = NR_EDI)) or
{ don't destroy if reg contains a parameter, local or global variable }
containsPointerLoad(c)
);
end;
end;
function writeToRegDestroysContents(destReg, supreg: tsuperregister;
const c: tcontent): boolean;
{ returns whether the contents c of reg are invalid after destReg is }
{ modified }
begin
writeToRegDestroysContents :=
(c.typ in [con_ref,con_noRemoveRef,con_invalid]) and
sequenceDependsOnReg(c,supreg,destReg);
end;
function writeDestroysContents(const op: toper; supreg: tsuperregister; size: tcgsize;
const c: tcontent; var memwritedestroyed: boolean): boolean;
{ returns whether the contents c of reg are invalid after regWritten is }
{ is written to op }
begin
memwritedestroyed := false;
case op.typ of
top_reg:
writeDestroysContents :=
(getregtype(op.reg) = R_INTREGISTER) and
writeToRegDestroysContents(getsupreg(op.reg),supreg,c);
top_ref:
writeDestroysContents :=
writeToMemDestroysContents(RS_INVALID,op.ref^,supreg,size,c,memwritedestroyed);
else
writeDestroysContents := false;
end;
end;
procedure destroyRefs(p: tai; const ref: treference; regwritten: tsuperregister; size: tcgsize);
{ destroys all registers which possibly contain a reference to ref, regWritten }
{ is the register whose contents are being written to memory (if this proc }
{ is called because of a "mov?? %reg, (mem)" instruction) }
var
counter: tsuperregister;
destroymemwrite: boolean;
begin
for counter := RS_EAX to RS_EDI Do
begin
if writeToMemDestroysContents(regwritten,ref,counter,size,
ptaiprop(p.optInfo)^.regs[counter],destroymemwrite) then
destroyReg(ptaiprop(p.optInfo), counter, false)
else if destroymemwrite then
ptaiprop(p.optinfo)^.regs[counter].MemWrite := nil;
end;
end;
procedure DestroyAllRegs(p: ptaiprop; read, written: boolean);
var Counter: tsuperregister;
begin {initializes/desrtoys all registers}
For Counter := RS_EAX To RS_EDI Do
begin
if read then
readreg(p, Counter);
DestroyReg(p, Counter, written);
p^.regs[counter].MemWrite := nil;
end;
p^.DirFlag := F_Unknown;
end;
procedure DestroyOp(taiObj: tai; const o:Toper);
{$ifdef statedebug}
var
hp: tai;
{$endif statedebug}
begin
case o.typ Of
top_reg:
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying '+std_regname(o.reg)));
hp.next := taiobj.next;
hp.previous := taiobj;
taiobj.next := hp;
if assigned(hp.next) then
hp.next.previous := hp;
{$endif statedebug}
DestroyReg(ptaiprop(taiObj.OptInfo), getsupreg(o.reg), true);
end;
top_ref:
begin
readref(ptaiprop(taiObj.OptInfo), o.ref);
DestroyRefs(taiObj, o.ref^, RS_INVALID,topsize2tcgsize[(taiobj as taicpu).opsize]);
end;
end;
end;
procedure AddInstr2RegContents({$ifdef statedebug} asml: TAsmList; {$endif}
p: taicpu; supreg: tsuperregister);
{$ifdef statedebug}
var
hp: tai;
{$endif statedebug}
begin
With ptaiprop(p.optinfo)^.regs[supreg] Do
if (typ in [con_ref,con_noRemoveRef]) then
begin
incState(wstate,1);
{ also store how many instructions are part of the sequence in the first }
{ instructions ptaiprop, so it can be easily accessed from within }
{ CheckSequence}
inc(NrOfMods, NrOfInstrSinceLastMod[supreg]);
ptaiprop(tai(StartMod).OptInfo)^.Regs[supreg].NrOfMods := NrOfMods;
NrOfInstrSinceLastMod[supreg] := 0;
invalidateDependingRegs(p.optinfo,supreg);
ptaiprop(p.optinfo)^.regs[supreg].memwrite := nil;
{$ifdef StateDebug}
hp := tai_comment.Create(strpnew(std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+': '+tostr(ptaiprop(p.optinfo)^.Regs[supreg].WState)
+ ' -- ' + tostr(ptaiprop(p.optinfo)^.Regs[supreg].nrofmods)));
InsertLLItem(AsmL, p, p.next, hp);
{$endif StateDebug}
end
else
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))));
insertllitem(asml,p,p.next,hp);
{$endif statedebug}
DestroyReg(ptaiprop(p.optinfo), supreg, true);
{$ifdef StateDebug}
hp := tai_comment.Create(strpnew(std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+': '+tostr(ptaiprop(p.optinfo)^.Regs[supreg].WState)));
InsertLLItem(AsmL, p, p.next, hp);
{$endif StateDebug}
end
end;
procedure AddInstr2OpContents({$ifdef statedebug} asml: TAsmList; {$endif}
p: taicpu; const oper: TOper);
begin
if oper.typ = top_reg then
AddInstr2RegContents({$ifdef statedebug} asml, {$endif}p, getsupreg(oper.reg))
else
begin
ReadOp(ptaiprop(p.optinfo), oper);
DestroyOp(p, oper);
end
end;
{*************************************************************************************}
{************************************** TDFAOBJ **************************************}
{*************************************************************************************}
constructor tdfaobj.create(_list: TAsmList);
begin
list := _list;
blockstart := nil;
blockend := nil;
nroftaiobjs := 0;
taipropblock := nil;
lolab := 0;
hilab := 0;
labdif := 0;
labeltable := nil;
end;
procedure tdfaobj.initlabeltable;
var
labelfound: boolean;
p, prev: tai;
hp1, hp2: tai;
{$ifdef i386}
regcounter,
supreg : tsuperregister;
{$endif i386}
usedregs, nodeallocregs: tregset;
begin
labelfound := false;
lolab := maxlongint;
hilab := 0;
p := blockstart;
prev := p;
while assigned(p) do
begin
if (tai(p).typ = ait_label) then
if not labelcanbeskipped(tai_label(p)) then
begin
labelfound := true;
if (tai_Label(p).labsym.labelnr < lolab) then
lolab := tai_label(p).labsym.labelnr;
if (tai_Label(p).labsym.labelnr > hilab) then
hilab := tai_label(p).labsym.labelnr;
end;
prev := p;
getnextinstruction(p, p);
end;
if (prev.typ = ait_marker) and
(tai_marker(prev).kind = mark_AsmBlockStart) then
blockend := prev
else blockend := nil;
if labelfound then
labdif := hilab+1-lolab
else labdif := 0;
usedregs := [];
if (labdif <> 0) then
begin
getmem(labeltable, labdif*sizeof(tlabeltableitem));
fillchar(labeltable^, labdif*sizeof(tlabeltableitem), 0);
end;
p := blockstart;
prev := p;
while (p <> blockend) do
begin
case p.typ of
ait_label:
if not labelcanbeskipped(tai_label(p)) then
labeltable^[tai_label(p).labsym.labelnr-lolab].taiobj := p;
{$ifdef i386}
ait_regalloc:
if (getregtype(tai_regalloc(p).reg) = R_INTREGISTER) then
begin
supreg:=getsupreg(tai_regalloc(p).reg);
case tai_regalloc(p).ratype of
ra_alloc :
begin
if not(supreg in usedregs) then
include(usedregs, supreg)
else
begin
//addregdeallocfor(list, tai_regalloc(p).reg, p);
hp1 := tai(p.previous);
list.remove(p);
p.free;
p := hp1;
end;
end;
ra_dealloc :
begin
exclude(usedregs, supreg);
hp1 := p;
hp2 := nil;
while not(findregalloc(supreg,tai(hp1.next),ra_alloc)) and
getnextinstruction(hp1, hp1) and
regininstruction(getsupreg(tai_regalloc(p).reg), hp1) Do
hp2 := hp1;
if hp2 <> nil then
begin
hp1 := tai(p.previous);
list.remove(p);
insertllitem(list, hp2, tai(hp2.next), p);
p := hp1;
end
else if findregalloc(getsupreg(tai_regalloc(p).reg), tai(p.next),ra_alloc)
and getnextinstruction(p,hp1) then
begin
hp1 := tai(p.previous);
list.remove(p);
p.free;
p := hp1;
// don't include here, since then the allocation will be removed when it's processed
// include(usedregs,supreg);
end;
end;
end;
end;
{$endif i386}
end;
repeat
prev := p;
p := tai(p.next);
until not(assigned(p)) or
(p = blockend) or
not(p.typ in (skipinstr - [ait_regalloc]));
end;
{$ifdef i386}
{ don't add deallocation for function result variable or for regvars}
getNoDeallocRegs(noDeallocRegs);
usedRegs := usedRegs - noDeallocRegs;
for regCounter := RS_EAX to RS_EDI do
if regCounter in usedRegs then
addRegDeallocFor(list,newreg(R_INTREGISTER,regCounter,R_SUBWHOLE),prev);
{$endif i386}
end;
function tdfaobj.pass_1(_blockstart: tai): tai;
begin
blockstart := _blockstart;
initlabeltable;
pass_1 := blockend;
end;
function tdfaobj.initdfapass2: boolean;
{reserves memory for the PtaiProps in one big memory block when not using
TP, returns False if not enough memory is available for the optimizer in all
cases}
var
p: tai;
count: Longint;
{ TmpStr: String; }
begin
p := blockstart;
skiphead(p);
nroftaiobjs := 0;
while (p <> blockend) do
begin
{$ifDef JumpAnal}
case p.typ of
ait_label:
begin
if not labelcanbeskipped(tai_label(p)) then
labeltable^[tai_label(p).labsym.labelnr-lolab].instrnr := nroftaiobjs
end;
ait_instruction:
begin
if taicpu(p).is_jmp then
begin
if (tasmlabel(taicpu(p).oper[0]^.sym).labsymabelnr >= lolab) and
(tasmlabel(taicpu(p).oper[0]^.sym).labsymabelnr <= hilab) then
inc(labeltable^[tasmlabel(taicpu(p).oper[0]^.sym).labsymabelnr-lolab].refsfound);
end;
end;
{ ait_instruction:
begin
if (taicpu(p).opcode = A_PUSH) and
(taicpu(p).oper[0]^.typ = top_symbol) and
(PCSymbol(taicpu(p).oper[0]^)^.offset = 0) then
begin
TmpStr := StrPas(PCSymbol(taicpu(p).oper[0]^)^.symbol);
if}
end;
{$endif JumpAnal}
inc(NrOftaiObjs);
getnextinstruction(p,p);
end;
if nroftaiobjs <> 0 then
begin
initdfapass2 := True;
getmem(taipropblock, nroftaiobjs*sizeof(ttaiprop));
fillchar(taiPropblock^,nroftaiobjs*sizeof(ttaiprop),0);
p := blockstart;
skiphead(p);
for count := 1 To nroftaiobjs do
begin
ptaiprop(p.optinfo) := @taipropblock^[count];
getnextinstruction(p, p);
end;
end
else
initdfapass2 := false;
end;
procedure tdfaobj.dodfapass2;
{Analyzes the Data Flow of an assembler list. Starts creating the reg
contents for the instructions starting with p. Returns the last tai which has
been processed}
var
curprop, LastFlagsChangeProp: ptaiprop;
Cnt, InstrCnt : Longint;
InstrProp: TInsProp;
UsedRegs: TRegSet;
prev,p : tai;
tmpref: TReference;
tmpsupreg: tsuperregister;
{$ifdef statedebug}
hp : tai;
{$endif}
{$ifdef AnalyzeLoops}
hp : tai;
TmpState: Byte;
{$endif AnalyzeLoops}
begin
p := BlockStart;
LastFlagsChangeProp := nil;
prev := nil;
UsedRegs := [];
UpdateUsedregs(UsedRegs, p);
SkipHead(p);
BlockStart := p;
InstrCnt := 1;
fillchar(NrOfInstrSinceLastMod, SizeOf(NrOfInstrSinceLastMod), 0);
while (p <> Blockend) Do
begin
curprop := @taiPropBlock^[InstrCnt];
if assigned(prev)
then
begin
{$ifdef JumpAnal}
if (p.Typ <> ait_label) then
{$endif JumpAnal}
begin
curprop^.regs := ptaiprop(prev.OptInfo)^.Regs;
curprop^.DirFlag := ptaiprop(prev.OptInfo)^.DirFlag;
curprop^.FlagsUsed := false;
end
end
else
begin
fillchar(curprop^, SizeOf(curprop^), 0);
{ For tmpreg := RS_EAX to RS_EDI Do
curprop^.regs[tmpreg].WState := 1;}
end;
curprop^.UsedRegs := UsedRegs;
curprop^.CanBeRemoved := False;
UpdateUsedRegs(UsedRegs, tai(p.Next));
For tmpsupreg := RS_EAX To RS_EDI Do
if NrOfInstrSinceLastMod[tmpsupreg] < 255 then
inc(NrOfInstrSinceLastMod[tmpsupreg])
else
begin
NrOfInstrSinceLastMod[tmpsupreg] := 0;
curprop^.regs[tmpsupreg].typ := con_unknown;
end;
case p.typ Of
ait_marker:;
ait_label:
{$ifndef JumpAnal}
if not labelCanBeSkipped(tai_label(p)) then
DestroyAllRegs(curprop,false,false);
{$else JumpAnal}
begin
if not labelCanBeSkipped(tai_label(p)) then
With LTable^[tai_Label(p).labsym^.labelnr-LoLab] Do
{$ifDef AnalyzeLoops}
if (RefsFound = tai_Label(p).labsym^.RefCount)
{$else AnalyzeLoops}
if (JmpsProcessed = tai_Label(p).labsym^.RefCount)
{$endif AnalyzeLoops}
then
{all jumps to this label have been found}
{$ifDef AnalyzeLoops}
if (JmpsProcessed > 0)
then
{$endif AnalyzeLoops}
{we've processed at least one jump to this label}
begin
if (GetLastInstruction(p, hp) and
not(((hp.typ = ait_instruction)) and
(taicpu_labeled(hp).is_jmp))
then
{previous instruction not a JMP -> the contents of the registers after the
previous intruction has been executed have to be taken into account as well}
For tmpsupreg := RS_EAX to RS_EDI Do
begin
if (curprop^.regs[tmpsupreg].WState <>
ptaiprop(hp.OptInfo)^.Regs[tmpsupreg].WState)
then DestroyReg(curprop, tmpsupreg, true)
end
end
{$ifDef AnalyzeLoops}
else
{a label from a backward jump (e.g. a loop), no jump to this label has
already been processed}
if GetLastInstruction(p, hp) and
not(hp.typ = ait_instruction) and
(taicpu_labeled(hp).opcode = A_JMP))
then
{previous instruction not a jmp, so keep all the registers' contents from the
previous instruction}
begin
curprop^.regs := ptaiprop(hp.OptInfo)^.Regs;
curprop.DirFlag := ptaiprop(hp.OptInfo)^.DirFlag;
end
else
{previous instruction a jmp and no jump to this label processed yet}
begin
hp := p;
Cnt := InstrCnt;
{continue until we find a jump to the label or a label which has already
been processed}
while GetNextInstruction(hp, hp) and
not((hp.typ = ait_instruction) and
(taicpu(hp).is_jmp) and
(tasmlabel(taicpu(hp).oper[0]^.sym).labsymabelnr = tai_Label(p).labsym^.labelnr)) and
not((hp.typ = ait_label) and
(LTable^[tai_Label(hp).labsym^.labelnr-LoLab].RefsFound
= tai_Label(hp).labsym^.RefCount) and
(LTable^[tai_Label(hp).labsym^.labelnr-LoLab].JmpsProcessed > 0)) Do
inc(Cnt);
if (hp.typ = ait_label)
then
{there's a processed label after the current one}
begin
curprop^.regs := taiPropBlock^[Cnt].Regs;
curprop.DirFlag := taiPropBlock^[Cnt].DirFlag;
end
else
{there's no label anymore after the current one, or they haven't been
processed yet}
begin
GetLastInstruction(p, hp);
curprop^.regs := ptaiprop(hp.OptInfo)^.Regs;
curprop.DirFlag := ptaiprop(hp.OptInfo)^.DirFlag;
DestroyAllRegs(ptaiprop(hp.OptInfo),true,true)
end
end
{$endif AnalyzeLoops}
else
{not all references to this label have been found, so destroy all registers}
begin
GetLastInstruction(p, hp);
curprop^.regs := ptaiprop(hp.OptInfo)^.Regs;
curprop.DirFlag := ptaiprop(hp.OptInfo)^.DirFlag;
DestroyAllRegs(curprop,true,true)
end;
end;
{$endif JumpAnal}
ait_stab, ait_force_line, ait_function_name:;
ait_align: ; { may destroy flags !!! }
ait_instruction:
begin
if taicpu(p).is_jmp or
(taicpu(p).opcode = A_JMP) then
begin
{$ifNDef JumpAnal}
for tmpsupreg := RS_EAX to RS_EDI do
with curprop^.regs[tmpsupreg] do
case typ of
con_ref: typ := con_noRemoveRef;
con_const: typ := con_noRemoveConst;
con_invalid: typ := con_unknown;
end;
{$else JumpAnal}
With LTable^[tasmlabel(taicpu(p).oper[0]^.sym).labsymabelnr-LoLab] Do
if (RefsFound = tasmlabel(taicpu(p).oper[0]^.sym).RefCount) then
begin
if (InstrCnt < InstrNr)
then
{forward jump}
if (JmpsProcessed = 0) then
{no jump to this label has been processed yet}
begin
taiPropBlock^[InstrNr].Regs := curprop^.regs;
taiPropBlock^[InstrNr].DirFlag := curprop.DirFlag;
inc(JmpsProcessed);
end
else
begin
For tmpreg := RS_EAX to RS_EDI Do
if (taiPropBlock^[InstrNr].Regs[tmpreg].WState <>
curprop^.regs[tmpreg].WState) then
DestroyReg(@taiPropBlock^[InstrNr], tmpreg, true);
inc(JmpsProcessed);
end
{$ifdef AnalyzeLoops}
else
{ backward jump, a loop for example}
{ if (JmpsProcessed > 0) or
not(GetLastInstruction(taiObj, hp) and
(hp.typ = ait_labeled_instruction) and
(taicpu_labeled(hp).opcode = A_JMP))
then}
{instruction prior to label is not a jmp, or at least one jump to the label
has yet been processed}
begin
inc(JmpsProcessed);
For tmpreg := RS_EAX to RS_EDI Do
if (taiPropBlock^[InstrNr].Regs[tmpreg].WState <>
curprop^.regs[tmpreg].WState)
then
begin
TmpState := taiPropBlock^[InstrNr].Regs[tmpreg].WState;
Cnt := InstrNr;
while (TmpState = taiPropBlock^[Cnt].Regs[tmpreg].WState) Do
begin
DestroyReg(@taiPropBlock^[Cnt], tmpreg, true);
inc(Cnt);
end;
while (Cnt <= InstrCnt) Do
begin
inc(taiPropBlock^[Cnt].Regs[tmpreg].WState);
inc(Cnt)
end
end;
end
{ else }
{instruction prior to label is a jmp and no jumps to the label have yet been
processed}
{ begin
inc(JmpsProcessed);
For tmpreg := RS_EAX to RS_EDI Do
begin
TmpState := taiPropBlock^[InstrNr].Regs[tmpreg].WState;
Cnt := InstrNr;
while (TmpState = taiPropBlock^[Cnt].Regs[tmpreg].WState) Do
begin
taiPropBlock^[Cnt].Regs[tmpreg] := curprop^.regs[tmpreg];
inc(Cnt);
end;
TmpState := taiPropBlock^[InstrNr].Regs[tmpreg].WState;
while (TmpState = taiPropBlock^[Cnt].Regs[tmpreg].WState) Do
begin
DestroyReg(@taiPropBlock^[Cnt], tmpreg, true);
inc(Cnt);
end;
while (Cnt <= InstrCnt) Do
begin
inc(taiPropBlock^[Cnt].Regs[tmpreg].WState);
inc(Cnt)
end
end
end}
{$endif AnalyzeLoops}
end;
{$endif JumpAnal}
end
else
begin
InstrProp := InsProp[taicpu(p).opcode];
case taicpu(p).opcode Of
A_MOV, A_MOVZX, A_MOVSX:
begin
case taicpu(p).oper[0]^.typ Of
top_ref, top_reg:
case taicpu(p).oper[1]^.typ Of
top_reg:
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying '+std_regname(taicpu(p).oper[1]^.reg)));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
readOp(curprop, taicpu(p).oper[0]^);
tmpsupreg := getsupreg(taicpu(p).oper[1]^.reg);
if reginop(tmpsupreg, taicpu(p).oper[0]^) and
(curprop^.regs[tmpsupreg].typ in [con_ref,con_noRemoveRef]) then
begin
with curprop^.regs[tmpsupreg] Do
begin
incState(wstate,1);
{ also store how many instructions are part of the sequence in the first }
{ instruction's ptaiprop, so it can be easily accessed from within }
{ CheckSequence }
inc(nrOfMods, nrOfInstrSinceLastMod[tmpsupreg]);
ptaiprop(startmod.optinfo)^.regs[tmpsupreg].nrOfMods := nrOfMods;
nrOfInstrSinceLastMod[tmpsupreg] := 0;
{ Destroy the contents of the registers }
{ that depended on the previous value of }
{ this register }
invalidateDependingRegs(curprop,tmpsupreg);
curprop^.regs[tmpsupreg].memwrite := nil;
end;
end
else
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying & initing '+std_regname(newreg(R_INTREGISTER,tmpsupreg,R_SUBWHOLE))));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
destroyReg(curprop, tmpsupreg, true);
if not(reginop(tmpsupreg, taicpu(p).oper[0]^)) then
with curprop^.regs[tmpsupreg] Do
begin
typ := con_ref;
startmod := p;
nrOfMods := 1;
end
end;
{$ifdef StateDebug}
hp := tai_comment.Create(strpnew(std_regname(newreg(R_INTREGISTER,tmpsupreg,R_SUBWHOLE))+': '+tostr(curprop^.regs[tmpsupreg].WState)));
insertllitem(list,p,p.next,hp);
{$endif StateDebug}
end;
top_ref:
begin
readref(curprop, taicpu(p).oper[1]^.ref);
if taicpu(p).oper[0]^.typ = top_reg then
begin
readreg(curprop, getsupreg(taicpu(p).oper[0]^.reg));
DestroyRefs(p, taicpu(p).oper[1]^.ref^, getsupreg(taicpu(p).oper[0]^.reg),topsize2tcgsize[taicpu(p).opsize]);
ptaiprop(p.optinfo)^.regs[getsupreg(taicpu(p).oper[0]^.reg)].memwrite :=
taicpu(p);
end
else
DestroyRefs(p, taicpu(p).oper[1]^.ref^, RS_INVALID,topsize2tcgsize[taicpu(p).opsize]);
end;
end;
top_Const:
begin
case taicpu(p).oper[1]^.typ Of
top_reg:
begin
tmpsupreg := getsupreg(taicpu(p).oper[1]^.reg);
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying '+std_regname(newreg(R_INTREGISTER,tmpsupreg,R_SUBWHOLE))));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
With curprop^.regs[tmpsupreg] Do
begin
DestroyReg(curprop, tmpsupreg, true);
typ := Con_Const;
StartMod := p;
nrOfMods := 1;
end
end;
top_ref:
begin
readref(curprop, taicpu(p).oper[1]^.ref);
DestroyRefs(p, taicpu(p).oper[1]^.ref^, RS_INVALID,topsize2tcgsize[taicpu(p).opsize]);
end;
end;
end;
end;
end;
A_DIV, A_IDIV, A_MUL:
begin
ReadOp(curprop, taicpu(p).oper[0]^);
readreg(curprop,RS_EAX);
if (taicpu(p).OpCode = A_IDIV) or
(taicpu(p).OpCode = A_DIV) then
begin
readreg(curprop,RS_EDX);
end;
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying eax and edx'));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
{ DestroyReg(curprop, RS_EAX, true);}
AddInstr2RegContents({$ifdef statedebug}list,{$endif}
taicpu(p), RS_EAX);
DestroyReg(curprop, RS_EDX, true);
LastFlagsChangeProp := curprop;
end;
A_IMUL:
begin
ReadOp(curprop,taicpu(p).oper[0]^);
if (taicpu(p).ops >= 2) then
ReadOp(curprop,taicpu(p).oper[1]^);
if (taicpu(p).ops <= 2) then
if (taicpu(p).ops=1) then
begin
readreg(curprop,RS_EAX);
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying eax and edx'));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
{ DestroyReg(curprop, RS_EAX, true); }
AddInstr2RegContents({$ifdef statedebug}list,{$endif}
taicpu(p), RS_EAX);
DestroyReg(curprop,RS_EDX, true)
end
else
AddInstr2OpContents(
{$ifdef statedebug}list,{$endif}
taicpu(p), taicpu(p).oper[1]^)
else
AddInstr2OpContents({$ifdef statedebug}list,{$endif}
taicpu(p), taicpu(p).oper[2]^);
LastFlagsChangeProp := curprop;
end;
A_LEA:
begin
readop(curprop,taicpu(p).oper[0]^);
if reginref(getsupreg(taicpu(p).oper[1]^.reg),taicpu(p).oper[0]^.ref^) then
AddInstr2RegContents({$ifdef statedebug}list,{$endif}
taicpu(p), getsupreg(taicpu(p).oper[1]^.reg))
else
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying & initing'+
std_regname(taicpu(p).oper[1]^.reg)));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
destroyreg(curprop,getsupreg(taicpu(p).oper[1]^.reg),true);
with curprop^.regs[getsupreg(taicpu(p).oper[1]^.reg)] Do
begin
typ := con_ref;
startmod := p;
nrOfMods := 1;
end
end;
end;
else
begin
Cnt := 1;
while (Cnt <= maxinschanges) and
(InstrProp.Ch[Cnt] <> Ch_None) Do
begin
case InstrProp.Ch[Cnt] Of
Ch_REAX..Ch_REDI:
begin
tmpsupreg:=tch2reg(InstrProp.Ch[Cnt]);
readreg(curprop,tmpsupreg);
end;
Ch_WEAX..Ch_RWEDI:
begin
if (InstrProp.Ch[Cnt] >= Ch_RWEAX) then
begin
tmpsupreg:=tch2reg(InstrProp.Ch[Cnt]);
readreg(curprop,tmpsupreg);
end;
{$ifdef statedebug}
hp := tai_comment.Create(strpnew('destroying '+
std_regname(tch2reg(InstrProp.Ch[Cnt]))));
insertllitem(list,p,p.next,hp);
{$endif statedebug}
tmpsupreg:=tch2reg(InstrProp.Ch[Cnt]);
DestroyReg(curprop,tmpsupreg, true);
end;
Ch_MEAX..Ch_MEDI:
begin
tmpsupreg:=tch2reg(InstrProp.Ch[Cnt]);
AddInstr2RegContents({$ifdef statedebug} list,{$endif}
taicpu(p),tmpsupreg);
end;
Ch_CDirFlag: curprop^.DirFlag := F_notSet;
Ch_SDirFlag: curprop^.DirFlag := F_Set;
Ch_Rop1: ReadOp(curprop, taicpu(p).oper[0]^);
Ch_Rop2: ReadOp(curprop, taicpu(p).oper[1]^);
Ch_ROp3: ReadOp(curprop, taicpu(p).oper[2]^);
Ch_Wop1..Ch_RWop1:
begin
if (InstrProp.Ch[Cnt] in [Ch_RWop1]) then
ReadOp(curprop, taicpu(p).oper[0]^);
DestroyOp(p, taicpu(p).oper[0]^);
end;
Ch_Mop1:
AddInstr2OpContents({$ifdef statedebug} list, {$endif}
taicpu(p), taicpu(p).oper[0]^);
Ch_Wop2..Ch_RWop2:
begin
if (InstrProp.Ch[Cnt] = Ch_RWop2) then
ReadOp(curprop, taicpu(p).oper[1]^);
DestroyOp(p, taicpu(p).oper[1]^);
end;
Ch_Mop2:
AddInstr2OpContents({$ifdef statedebug} list, {$endif}
taicpu(p), taicpu(p).oper[1]^);
Ch_WOp3..Ch_RWOp3:
begin
if (InstrProp.Ch[Cnt] = Ch_RWOp3) then
ReadOp(curprop, taicpu(p).oper[2]^);
DestroyOp(p, taicpu(p).oper[2]^);
end;
Ch_Mop3:
AddInstr2OpContents({$ifdef statedebug} list, {$endif}
taicpu(p), taicpu(p).oper[2]^);
Ch_WMemEDI:
begin
readreg(curprop, RS_EDI);
fillchar(tmpref, SizeOf(tmpref), 0);
tmpref.base := NR_EDI;
tmpref.index := NR_EDI;
DestroyRefs(p, tmpref,RS_INVALID,OS_32)
end;
Ch_RFlags:
if assigned(LastFlagsChangeProp) then
LastFlagsChangeProp^.FlagsUsed := true;
Ch_WFlags:
LastFlagsChangeProp := curprop;
Ch_RWFlags:
begin
if assigned(LastFlagsChangeProp) then
LastFlagsChangeProp^.FlagsUsed := true;
LastFlagsChangeProp := curprop;
end;
Ch_FPU:;
else
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew(
'destroying all regs for prev instruction'));
insertllitem(list,p, p.next,hp);
{$endif statedebug}
DestroyAllRegs(curprop,true,true);
LastFlagsChangeProp := curprop;
end;
end;
inc(Cnt);
end
end;
end;
end;
end
else
begin
{$ifdef statedebug}
hp := tai_comment.Create(strpnew(
'destroying all regs: unknown tai: '+tostr(ord(p.typ))));
insertllitem(list,p, p.next,hp);
{$endif statedebug}
DestroyAllRegs(curprop,true,true);
end;
end;
inc(InstrCnt);
prev := p;
GetNextInstruction(p, p);
end;
end;
function tdfaobj.pass_generate_code: boolean;
begin
if initdfapass2 then
begin
dodfapass2;
pass_generate_code := true
end
else
pass_generate_code := false;
end;
{$ifopt r+}
{$define rangewason}
{$r-}
{$endif}
function tdfaobj.getlabelwithsym(sym: tasmlabel): tai;
begin
if (sym.labelnr >= lolab) and
(sym.labelnr <= hilab) then { range check, a jump can go past an assembler block! }
getlabelwithsym := labeltable^[sym.labelnr-lolab].taiobj
else
getlabelwithsym := nil;
end;
{$ifdef rangewason}
{$r+}
{$undef rangewason}
{$endif}
procedure tdfaobj.clear;
begin
if labdif <> 0 then
begin
freemem(labeltable);
labeltable := nil;
end;
if assigned(taipropblock) then
begin
freemem(taipropblock, nroftaiobjs*sizeof(ttaiprop));
taipropblock := nil;
end;
end;
end.
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