fpc/compiler/daopt386.pas
2000-02-24 18:41:38 +00:00

2217 lines
77 KiB
ObjectPascal

{
$Id$
Copyright (c) 1998-2000 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.
****************************************************************************
}
{$ifDef TP}
{$UnDef JumpAnal}
{$Endif TP}
Unit DAOpt386;
{$ifdef newOptimizations}
{$define foropt}
{$define replacereg}
{$define arithopt}
{$define foldarithops}
{$endif newOptimizations}
Interface
Uses
GlobType,
CObjects,Aasm,
cpubase,cpuasm;
Type
TRegArray = Array[R_EAX..R_BL] of TRegister;
TRegSet = Set of R_EAX..R_BL;
TRegInfo = Record
NewRegsEncountered, OldRegsEncountered: TRegSet;
RegsLoadedForRef: TRegSet;
New2OldReg: TRegArray;
End;
{possible actions on an operand: read, write or modify (= read & write)}
TOpAction = (OpAct_Read, OpAct_Write, OpAct_Modify, OpAct_Unknown);
{*********************** Procedures and Functions ************************}
Procedure InsertLLItem(AsmL: PAasmOutput; prev, foll, new_one: PLinkedList_Item);
Function Reg32(Reg: TRegister): TRegister;
Function RefsEquivalent(Const R1, R2: TReference; Var RegInfo: TRegInfo; OpAct: TOpAction): Boolean;
Function RefsEqual(Const R1, R2: TReference): Boolean;
Function IsGP32Reg(Reg: TRegister): Boolean;
Function RegInRef(Reg: TRegister; Const Ref: TReference): Boolean;
Function RegInInstruction(Reg: TRegister; p1: Pai): Boolean;
{$ifdef newOptimizations}
Function RegInOp(Reg: TRegister; const o:toper): Boolean;
{$endif newOptimizations}
Function RegModifiedByInstruction(Reg: TRegister; p1: Pai): Boolean;
Function GetNextInstruction(Current: Pai; Var Next: Pai): Boolean;
Function GetLastInstruction(Current: Pai; Var Last: Pai): Boolean;
Procedure SkipHead(var P: Pai);
Procedure RemoveLastDeallocForFuncRes(asmL: PAasmOutput; p: pai);
Function regLoadedWithNewValue(reg: tregister; canDependOnPrevValue: boolean;
hp: pai): boolean;
Procedure UpdateUsedRegs(Var UsedRegs: TRegSet; p: Pai);
Function RegsEquivalent(OldReg, NewReg: TRegister; Var RegInfo: TRegInfo; OpAct: TopAction): Boolean;
Function InstructionsEquivalent(p1, p2: Pai; Var RegInfo: TRegInfo): Boolean;
Function OpsEqual(const o1,o2:toper): Boolean;
Function DFAPass1(AsmL: PAasmOutput; BlockStart: Pai): Pai;
Function DFAPass2(
{$ifdef statedebug}
AsmL: PAasmOutPut;
{$endif statedebug}
BlockStart, BlockEnd: Pai): Boolean;
Procedure ShutDownDFA;
Function FindLabel(L: PasmLabel; Var hp: Pai): Boolean;
{******************************* Constants *******************************}
Const
{Possible register content types}
con_Unknown = 0;
con_ref = 1;
con_const = 2;
{********************************* Types *********************************}
type
{the possible states of a flag}
TFlagContents = (F_Unknown, F_NotSet, F_Set);
TContent = Packed Record
{start and end of block instructions that defines the
content of this register.}
StartMod: pai;
{starts at 0, gets increased everytime the register is written to}
WState: Byte;
{starts at 0, gets increased everytime the register is read from}
RState: Byte;
{how many instructions starting with StarMod does the block consist of}
NrOfMods: Byte;
{the type of the content of the register: unknown, memory, constant}
Typ: Byte;
End;
{Contents of the integer registers}
TRegContent = Array[R_EAX..R_EDI] Of TContent;
{contents of the FPU registers}
TRegFPUContent = Array[R_ST..R_ST7] Of TContent;
{$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;
{$endif tempOpts}
{information record with the contents of every register. Every Pai object
gets one of these assigned: a pointer to it is stored in the OptInfo field}
TPaiProp = Record
Regs: TRegContent;
{ FPURegs: TRegFPUContent;} {currently not yet used}
{ allocated Registers }
UsedRegs: TRegSet;
{ status of the direction flag }
DirFlag: TFlagContents;
{$ifdef tempOpts}
{ currently used temps }
tempAllocs: PSearchLinkedList;
{$endif tempOpts}
{ can this instruction be removed? }
CanBeRemoved: Boolean;
End;
PPaiProp = ^TPaiProp;
{$IfNDef TP}
TPaiPropBlock = Array[1..250000] Of TPaiProp;
PPaiPropBlock = ^TPaiPropBlock;
{$EndIf TP}
TInstrSinceLastMod = Array[R_EAX..R_EDI] Of Byte;
TLabelTableItem = Record
PaiObj: Pai;
{$IfDef JumpAnal}
InstrNr: Longint;
RefsFound: Word;
JmpsProcessed: Word
{$EndIf JumpAnal}
End;
{$IfDef tp}
TLabelTable = Array[0..10000] Of TLabelTableItem;
{$Else tp}
TLabelTable = Array[0..2500000] Of TLabelTableItem;
{$Endif tp}
PLabelTable = ^TLabelTable;
{******************************* Variables *******************************}
Var
{the amount of PaiObjects in the current assembler list}
NrOfPaiObjs: Longint;
{$IfNDef TP}
{Array which holds all TPaiProps}
PaiPropBlock: PPaiPropBlock;
{$EndIf TP}
LoLab, HiLab, LabDif: Longint;
LTable: PLabelTable;
{*********************** End of Interface section ************************}
Implementation
Uses
globals, systems, strings, verbose, hcodegen, symconst, tgeni386;
Type
TRefCompare = function(const r1, r2: TReference): Boolean;
Var
{How many instructions are between the current instruction and the last one
that modified the register}
NrOfInstrSinceLastMod: TInstrSinceLastMod;
{$ifdef tempOpts}
constructor TSearchLinkedListItem.init;
begin
end;
function TSearchLinkedListItem.equals(p: PSearchLinkedListItem): boolean;
begin
equals := false;
end;
constructor TSearchDoubleIntItem.init(_int1,_int2: longint);
begin
int1 := _int1;
int2 := _int2;
end;
function TSearchDoubleIntItem.equals(p: PSearchLinkedListItem): boolean;
begin
equals := (TSearchDoubleIntItem(p).int1 = int1) and
(TSearchDoubleIntItem(p).int2 = int2);
end;
function TSearchLinkedList.searchByValue(p: PSearchLinkedListItem): boolean;
var temp: PSearchLinkedListItem;
begin
temp := first;
while (temp <> last^.next) and
not(temp^.equals(p)) do
temp := temp^.next;
searchByValue := temp <> last^.next;
end;
procedure TSearchLinkedList.removeByValue(p: PSearchLinkedListItem);
begin
temp := first;
while (temp <> last^.next) and
not(temp^.equals(p)) do
temp := temp^.next;
if temp <> last^.next then
begin
remove(temp);
dispose(temp,done);
end;
end;
Procedure updateTempAllocs(Var UsedRegs: TRegSet; p: Pai);
{updates UsedRegs with the RegAlloc Information coming after P}
Begin
Repeat
While Assigned(p) And
((p^.typ in (SkipInstr - [ait_RegAlloc])) or
((p^.typ = ait_label) And
Not(Pai_Label(p)^.l^.is_used))) Do
p := Pai(p^.next);
While Assigned(p) And
(p^.typ=ait_RegAlloc) Do
Begin
if pairegalloc(p)^.allocation then
UsedRegs := UsedRegs + [PaiRegAlloc(p)^.Reg]
else
UsedRegs := UsedRegs - [PaiRegAlloc(p)^.Reg];
p := pai(p^.next);
End;
Until Not(Assigned(p)) Or
(Not(p^.typ in SkipInstr) And
Not((p^.typ = ait_label) And
Not(Pai_Label(p)^.l^.is_used)));
End;
{$endif tempOpts}
{************************ Create the Label table ************************}
Function FindLoHiLabels(Var LowLabel, HighLabel, LabelDif: Longint; BlockStart: Pai): Pai;
{Walks through the paasmlist to find the lowest and highest label number}
Var LabelFound: Boolean;
P, lastP: Pai;
Begin
LabelFound := False;
LowLabel := MaxLongint;
HighLabel := 0;
P := BlockStart;
lastP := p;
While Assigned(P) Do
Begin
If (Pai(p)^.typ = ait_label) Then
If (Pai_Label(p)^.l^.is_used)
Then
Begin
LabelFound := True;
If (Pai_Label(p)^.l^.labelnr < LowLabel) Then
LowLabel := Pai_Label(p)^.l^.labelnr;
If (Pai_Label(p)^.l^.labelnr > HighLabel) Then
HighLabel := Pai_Label(p)^.l^.labelnr;
End;
lastP := p;
GetNextInstruction(p, p);
End;
if (lastP^.typ = ait_marker) and
(pai_marker(lastP)^.kind = asmBlockStart) then
FindLoHiLabels := lastP
else FindLoHiLabels := nil;
If LabelFound
Then LabelDif := HighLabel+1-LowLabel
Else LabelDif := 0;
End;
Function FindRegAlloc(Reg: TRegister; StartPai: Pai; alloc: boolean): Boolean;
{ Returns true if a ait_alloc object for Reg is found in the block of Pai's }
{ starting with StartPai and ending with the next "real" instruction }
Begin
FindRegAlloc := false;
Repeat
While Assigned(StartPai) And
((StartPai^.typ in (SkipInstr - [ait_regAlloc])) Or
((StartPai^.typ = ait_label) and
Not(Pai_Label(StartPai)^.l^.Is_Used))) Do
StartPai := Pai(StartPai^.Next);
If Assigned(StartPai) And
(StartPai^.typ = ait_regAlloc) and (PairegAlloc(StartPai)^.allocation = alloc) Then
Begin
if PairegAlloc(StartPai)^.Reg = Reg then
begin
FindRegAlloc:=true;
break;
end;
StartPai := Pai(StartPai^.Next);
End
else
break;
Until false;
End;
Procedure RemoveLastDeallocForFuncRes(asmL: PAasmOutput; p: pai);
Procedure DoRemoveLastDeallocForFuncRes(asmL: PAasmOutput; reg: TRegister);
var
hp2: pai;
begin
hp2 := p;
repeat
hp2 := pai(hp2^.previous);
if assigned(hp2) and
(hp2^.typ = ait_regalloc) and
not(pairegalloc(hp2)^.allocation) and
(pairegalloc(hp2)^.reg = reg) then
begin
asml^.remove(hp2);
dispose(hp2,done);
break;
end;
until not(assigned(hp2)) or
regInInstruction(reg,hp2);
end;
begin
if assigned(procinfo^.returntype.def) then
case procinfo^.returntype.def^.deftype of
arraydef,recorddef,pointerdef,
stringdef,enumdef,procdef,objectdef,errordef,
filedef,setdef,procvardef,
classrefdef,forwarddef:
DoRemoveLastDeallocForFuncRes(asmL,R_EAX);
orddef:
if procinfo^.returntype.def^.size <> 0 then
begin
DoRemoveLastDeallocForFuncRes(asmL,R_EAX);
{ for int64/qword }
if procinfo^.returntype.def^.size = 8 then
DoRemoveLastDeallocForFuncRes(asmL,R_EDX);
end;
end;
end;
procedure getNoDeallocRegs(var regs: TRegSet);
var regCounter: TRegister;
begin
regs := [];
if assigned(procinfo^.returntype.def) then
case procinfo^.returntype.def^.deftype of
arraydef,recorddef,pointerdef,
stringdef,enumdef,procdef,objectdef,errordef,
filedef,setdef,procvardef,
classrefdef,forwarddef:
regs := [R_EAX];
orddef:
if procinfo^.returntype.def^.size <> 0 then
begin
regs := [R_EAX];
{ for int64/qword }
if procinfo^.returntype.def^.size = 8 then
regs := regs + [R_EDX];
end;
end;
for regCounter := R_EAX to R_EBX do
if not(regCounter in usableregs) then
regs := regs + [regCounter];
end;
Procedure AddRegDeallocFor(asmL: paasmOutput; reg: TRegister; p: pai);
var hp1: pai;
funcResRegs: TRegset;
funcResReg: boolean;
begin
if not(reg in usableregs) then
exit;
getNoDeallocRegs(funcResRegs);
funcResRegs := funcResRegs - usableregs;
funcResReg := reg in funcResRegs;
hp1 := p;
while not(funcResReg and
(p^.typ = ait_instruction) and
(paicpu(p)^.opcode = A_JMP) and
(pasmlabel(paicpu(p)^.oper[0].sym) = aktexit2label)) and
getLastInstruction(p, p) And
not(regInInstruction(reg, 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
(paicpu(hp1)^.opcode = A_JMP) and
(pasmlabel(paicpu(hp1)^.oper[0].sym) = aktexit2label)) then
begin
p := new(paiRegAlloc, deAlloc(reg));
insertLLItem(AsmL, hp1^.previous, hp1, p);
end;
end;
Procedure BuildLabelTableAndFixRegAlloc(asmL: PAasmOutput; Var LabelTable: PLabelTable; LowLabel: Longint;
Var LabelDif: Longint; BlockStart, BlockEnd: Pai);
{Builds a table with the locations of the labels in the paasmoutput.
Also fixes some RegDeallocs like "# %eax released; push (%eax)"}
Var p, hp1, hp2, lastP: Pai;
regCounter: TRegister;
UsedRegs, noDeallocRegs: TRegSet;
Begin
UsedRegs := [];
If (LabelDif <> 0) Then
Begin
{$IfDef TP}
If (MaxAvail >= LabelDif*SizeOf(Pai))
Then
Begin
{$EndIf TP}
GetMem(LabelTable, LabelDif*SizeOf(TLabelTableItem));
FillChar(LabelTable^, LabelDif*SizeOf(TLabelTableItem), 0);
{$IfDef TP}
End
Else LabelDif := 0;
{$EndIf TP}
End;
p := BlockStart;
lastP := p;
While (P <> BlockEnd) Do
Begin
Case p^.typ Of
ait_Label:
If Pai_Label(p)^.l^.is_used Then
LabelTable^[Pai_Label(p)^.l^.labelnr-LowLabel].PaiObj := p;
ait_regAlloc:
{ ESI and EDI are (de)allocated manually, don't mess with them }
if not(paiRegAlloc(p)^.Reg in [R_EDI,R_ESI]) then
begin
if PairegAlloc(p)^.Allocation then
Begin
If Not(paiRegAlloc(p)^.Reg in UsedRegs) Then
UsedRegs := UsedRegs + [paiRegAlloc(p)^.Reg]
Else
addRegDeallocFor(asmL, paiRegAlloc(p)^.reg, p);
End
else
begin
UsedRegs := UsedRegs - [paiRegAlloc(p)^.Reg];
hp1 := p;
hp2 := nil;
While Not(FindRegAlloc(paiRegAlloc(p)^.Reg, Pai(hp1^.Next),true)) And
GetNextInstruction(hp1, hp1) And
RegInInstruction(paiRegAlloc(p)^.Reg, hp1) Do
hp2 := hp1;
If hp2 <> nil Then
Begin
hp1 := Pai(p^.previous);
AsmL^.Remove(p);
InsertLLItem(AsmL, hp2, Pai(hp2^.Next), p);
p := hp1;
end;
end;
end;
end;
repeat
lastP := p;
P := Pai(P^.Next);
until not(Assigned(p)) or
not(p^.typ in (SkipInstr - [ait_regalloc]));
End;
{ don't add deallocation for function result variable or for regvars}
getNoDeallocRegs(noDeallocRegs);
usedRegs := usedRegs - noDeallocRegs;
for regCounter := R_EAX to R_EDI do
if regCounter in usedRegs then
addRegDeallocFor(asmL,regCounter,lastP);
End;
{************************ Search the Label table ************************}
Function FindLabel(L: PasmLabel; Var hp: Pai): 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 TempP: Pai;
Begin
TempP := hp;
While Assigned(TempP) and
(TempP^.typ In SkipInstr + [ait_label,ait_align]) Do
If (TempP^.typ <> ait_Label) Or
(pai_label(TempP)^.l <> L)
Then GetNextInstruction(TempP, TempP)
Else
Begin
hp := TempP;
FindLabel := True;
exit
End;
FindLabel := False;
End;
{************************ Some general functions ************************}
Function TCh2Reg(Ch: TInsChange): TRegister;
{converts a TChange variable to a TRegister}
Begin
If (Ch <= Ch_REDI) Then
TCh2Reg := TRegister(Byte(Ch))
Else
If (Ch <= Ch_WEDI) Then
TCh2Reg := TRegister(Byte(Ch) - Byte(Ch_REDI))
Else
If (Ch <= Ch_RWEDI) Then
TCh2Reg := TRegister(Byte(Ch) - Byte(Ch_WEDI))
Else
If (Ch <= Ch_MEDI) Then
TCh2Reg := TRegister(Byte(Ch) - Byte(Ch_RWEDI))
Else InternalError($db)
End;
Function Reg32(Reg: TRegister): TRegister;
{Returns the 32 bit component of Reg if it exists, otherwise Reg is returned}
Begin
Reg32 := Reg;
If (Reg >= R_AX)
Then
If (Reg <= R_DI)
Then Reg32 := Reg16ToReg32(Reg)
Else
If (Reg <= R_BL)
Then Reg32 := Reg8toReg32(Reg);
End;
{ inserts new_one between prev and foll }
Procedure InsertLLItem(AsmL: PAasmOutput; prev, foll, new_one: PLinkedList_Item);
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;
Pai(new_one)^.fileinfo := Pai(foll)^.fileinfo;
End;
End
Else AsmL^.Concat(new_one)
Else If Assigned(Foll) Then AsmL^.Insert(new_one)
End;
{********************* Compare parts of Pai 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 <= R_EDI)
Then RegsSameSize := (Reg2 <= R_EDI)
Else
If (Reg1 <= R_DI)
Then RegsSameSize := (Reg2 in [R_AX..R_DI])
Else
If (Reg1 <= R_BL)
Then RegsSameSize := (Reg2 in [R_AL..R_BL])
Else RegsSameSize := False
End;
Procedure AddReg2RegInfo(OldReg, NewReg: TRegister; Var RegInfo: TRegInfo);
{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 R_NO}
Begin
With RegInfo Do
Begin
NewRegsEncountered := NewRegsEncountered + [NewReg];
OldRegsEncountered := OldRegsEncountered + [OldReg];
New2OldReg[NewReg] := OldReg;
Case OldReg Of
R_EAX..R_EDI:
Begin
NewRegsEncountered := NewRegsEncountered + [Reg32toReg16(NewReg)];
OldRegsEncountered := OldRegsEncountered + [Reg32toReg16(OldReg)];
New2OldReg[Reg32toReg16(NewReg)] := Reg32toReg16(OldReg);
If (NewReg in [R_EAX..R_EBX]) And
(OldReg in [R_EAX..R_EBX]) Then
Begin
NewRegsEncountered := NewRegsEncountered + [Reg32toReg8(NewReg)];
OldRegsEncountered := OldRegsEncountered + [Reg32toReg8(OldReg)];
New2OldReg[Reg32toReg8(NewReg)] := Reg32toReg8(OldReg);
End;
End;
R_AX..R_DI:
Begin
NewRegsEncountered := NewRegsEncountered + [Reg16toReg32(NewReg)];
OldRegsEncountered := OldRegsEncountered + [Reg16toReg32(OldReg)];
New2OldReg[Reg16toReg32(NewReg)] := Reg16toReg32(OldReg);
If (NewReg in [R_AX..R_BX]) And
(OldReg in [R_AX..R_BX]) Then
Begin
NewRegsEncountered := NewRegsEncountered + [Reg16toReg8(NewReg)];
OldRegsEncountered := OldRegsEncountered + [Reg16toReg8(OldReg)];
New2OldReg[Reg16toReg8(NewReg)] := Reg16toReg8(OldReg);
End;
End;
R_AL..R_BL:
Begin
NewRegsEncountered := NewRegsEncountered + [Reg8toReg32(NewReg)]
+ [Reg8toReg16(NewReg)];
OldRegsEncountered := OldRegsEncountered + [Reg8toReg32(OldReg)]
+ [Reg8toReg16(OldReg)];
New2OldReg[Reg8toReg32(NewReg)] := Reg8toReg32(OldReg);
End;
End;
End;
End;
Procedure AddOp2RegInfo(const o:Toper; Var RegInfo: TRegInfo);
Begin
Case o.typ Of
Top_Reg:
If (o.reg <> R_NO) Then
AddReg2RegInfo(o.reg, o.reg, RegInfo);
Top_Ref:
Begin
If o.ref^.base <> R_NO Then
AddReg2RegInfo(o.ref^.base, o.ref^.base, RegInfo);
If o.ref^.index <> R_NO Then
AddReg2RegInfo(o.ref^.index, o.ref^.index, RegInfo);
End;
End;
End;
Function RegsEquivalent(OldReg, NewReg: TRegister; Var RegInfo: TRegInfo; OPAct: TOpAction): Boolean;
Begin
If Not((OldReg = R_NO) Or (NewReg = R_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 R_NO and the comparison in the Else-part will fail}
If (Reg32(OldReg) in OldRegsEncountered) Then
If (Reg32(NewReg) in NewRegsEncountered) Then
RegsEquivalent := (OldReg = New2OldReg[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(Reg32(NewReg) in NewRegsEncountered) 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; var RegInfo: TRegInfo; OpAct: TOpAction): Boolean;
Begin
If R1.is_immediate Then
RefsEquivalent := R2.is_immediate and (R1.Offset = R2.Offset)
Else
RefsEquivalent := (R1.Offset+R1.OffsetFixup = R2.Offset+R2.OffsetFixup) And
RegsEquivalent(R1.Base, R2.Base, RegInfo, OpAct) And
RegsEquivalent(R1.Index, R2.Index, RegInfo, OpAct) And
(R1.Segment = R2.Segment) And (R1.ScaleFactor = R2.ScaleFactor) And
(R1.Symbol = R2.Symbol);
End;
Function RefsEqual(Const R1, R2: TReference): Boolean;
Begin
If R1.is_immediate Then
RefsEqual := R2.is_immediate and (R1.Offset = R2.Offset)
Else
RefsEqual := (R1.Offset+R1.OffsetFixup = R2.Offset+R2.OffsetFixup) 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);
End;
Function IsGP32Reg(Reg: TRegister): Boolean;
{Checks if the register is a 32 bit general purpose register}
Begin
If (Reg >= R_EAX) and (Reg <= R_EBX)
Then IsGP32Reg := True
Else IsGP32reg := False
End;
Function RegInRef(Reg: TRegister; Const Ref: TReference): Boolean;
Begin {checks whether Ref contains a reference to Reg}
Reg := Reg32(Reg);
RegInRef := (Ref.Base = Reg) Or (Ref.Index = Reg)
End;
Function RegInInstruction(Reg: TRegister; p1: Pai): Boolean;
{checks if Reg is used by the instruction p1}
Var Counter: Longint;
TmpResult: Boolean;
Begin
TmpResult := False;
If (Pai(p1)^.typ = ait_instruction) Then
Begin
Reg := Reg32(Reg);
Counter := 0;
Repeat
Case Paicpu(p1)^.oper[Counter].typ Of
Top_Reg: TmpResult := Reg = Reg32(Paicpu(p1)^.oper[Counter].reg);
Top_Ref: TmpResult := RegInRef(Reg, Paicpu(p1)^.oper[Counter].ref^);
End;
Inc(Counter)
Until (Counter = 3) or TmpResult;
End;
RegInInstruction := TmpResult
End;
{$ifdef newOptimizations}
Function RegInOp(Reg: TRegister; const o:toper): Boolean;
Begin
RegInOp := False;
Case o.typ Of
top_reg: RegInOp := Reg = o.reg;
top_ref: RegInOp := (Reg = o.ref^.Base) Or
(Reg = o.ref^.Index);
End;
End;
{$endif newOptimizations}
(*
Function RegModifiedByInstruction(Reg: TRegister; p1: Pai): Boolean;
{returns true if Reg is modified by the instruction p1. P1 is assumed to be
of the type ait_instruction}
Var hp: Pai;
Begin
If GetLastInstruction(p1, hp)
Then
RegModifiedByInstruction :=
PPAiProp(p1^.OptInfo)^.Regs[Reg].WState <>
PPAiProp(hp^.OptInfo)^.Regs[Reg].WState
Else RegModifiedByInstruction := True;
End;
*)
Function RegModifiedByInstruction(Reg: TRegister; p1: Pai): Boolean;
Var InstrProp: TInsProp;
TmpResult: Boolean;
Cnt: Byte;
Begin
TmpResult := False;
Reg := Reg32(Reg);
If (p1^.typ = ait_instruction) Then
Case paicpu(p1)^.opcode of
A_IMUL:
With paicpu(p1)^ Do
TmpResult :=
((ops = 1) and (reg = R_EAX)) or
((ops = 2) and (Reg32(oper[1].reg) = reg)) or
((ops = 3) and (Reg32(oper[2].reg) = reg));
A_DIV, A_IDIV, A_MUL:
With paicpu(p1)^ Do
TmpResult :=
(Reg = R_EAX) or
(Reg = R_EDX);
Else
Begin
Cnt := 1;
InstrProp := InsProp[paicpu(p1)^.OpCode];
While (Cnt <= MaxCh) And
(InstrProp.Ch[Cnt] <> Ch_None) And
Not(TmpResult) Do
Begin
Case InstrProp.Ch[Cnt] Of
Ch_WEAX..Ch_MEDI:
TmpResult := Reg = TCh2Reg(InstrProp.Ch[Cnt]);
Ch_RWOp1,Ch_WOp1{$ifdef arithopt},Ch_Mop1{$endif arithopt}:
TmpResult := (paicpu(p1)^.oper[0].typ = top_reg) and
(Reg32(paicpu(p1)^.oper[0].reg) = reg);
Ch_RWOp2,Ch_WOp2{$ifdef arithopt},Ch_Mop2{$endif arithopt}:
TmpResult := (paicpu(p1)^.oper[1].typ = top_reg) and
(Reg32(paicpu(p1)^.oper[1].reg) = reg);
Ch_RWOp3,Ch_WOp3{$ifdef arithopt},Ch_Mop3{$endif arithopt}:
TmpResult := (paicpu(p1)^.oper[2].typ = top_reg) and
(Reg32(paicpu(p1)^.oper[2].reg) = reg);
Ch_FPU: TmpResult := Reg in [R_ST..R_ST7,R_MM0..R_MM7];
Ch_ALL: TmpResult := true;
End;
Inc(Cnt)
End
End
End;
RegModifiedByInstruction := TmpResult
End;
{********************* GetNext and GetLastInstruction *********************}
Function GetNextInstruction(Current: Pai; Var Next: Pai): Boolean;
{ skips ait_regalloc, ait_regdealloc and ait_stab* objects and puts the }
{ next pai object in Next. Returns false if there isn't any }
Begin
Repeat
If (Current^.typ = ait_marker) And
(Pai_Marker(Current)^.Kind = AsmBlockStart) Then
Begin
GetNextInstruction := False;
Next := Nil;
Exit
End;
Current := Pai(Current^.Next);
While Assigned(Current) And
((Current^.typ In SkipInstr) or
((Current^.typ = ait_label) And
Not(Pai_Label(Current)^.l^.is_used))) Do
Current := Pai(Current^.Next);
If Assigned(Current) And
(Current^.typ = ait_Marker) And
(Pai_Marker(Current)^.Kind = NoPropInfoStart) Then
Begin
While Assigned(Current) And
((Current^.typ <> ait_Marker) Or
(Pai_Marker(Current)^.Kind <> NoPropInfoEnd)) Do
Current := Pai(Current^.Next);
End;
Until Not(Assigned(Current)) Or
(Current^.typ <> ait_Marker) Or
(Pai_Marker(Current)^.Kind <> NoPropInfoEnd);
Next := Current;
If Assigned(Current) And
Not((Current^.typ In SkipInstr) or
((Current^.typ = ait_label) And
Not(Pai_Label(Current)^.l^.is_used)))
Then
GetNextInstruction :=
not((current^.typ = ait_marker) and
(pai_marker(current)^.kind = asmBlockStart))
Else
Begin
GetNextInstruction := False;
Next := nil;
End;
End;
Function GetLastInstruction(Current: Pai; Var Last: Pai): Boolean;
{skips the ait-types in SkipInstr puts the previous pai object in
Last. Returns false if there isn't any}
Begin
Repeat
Current := Pai(Current^.previous);
While Assigned(Current) And
(((Current^.typ = ait_Marker) And
Not(Pai_Marker(Current)^.Kind in [AsmBlockEnd,NoPropInfoEnd])) or
(Current^.typ In SkipInstr) or
((Current^.typ = ait_label) And
Not(Pai_Label(Current)^.l^.is_used))) Do
Current := Pai(Current^.previous);
If Assigned(Current) And
(Current^.typ = ait_Marker) And
(Pai_Marker(Current)^.Kind = NoPropInfoEnd) Then
Begin
While Assigned(Current) And
((Current^.typ <> ait_Marker) Or
(Pai_Marker(Current)^.Kind <> NoPropInfoStart)) Do
Current := Pai(Current^.previous);
End;
Until Not(Assigned(Current)) Or
(Current^.typ <> ait_Marker) Or
(Pai_Marker(Current)^.Kind <> NoPropInfoStart);
If Not(Assigned(Current)) or
(Current^.typ In SkipInstr) or
((Current^.typ = ait_label) And
Not(Pai_Label(Current)^.l^.is_used)) or
((Current^.typ = ait_Marker) And
(Pai_Marker(Current)^.Kind = AsmBlockEnd))
Then
Begin
Last := nil;
GetLastInstruction := False
End
Else
Begin
Last := Current;
GetLastInstruction := True;
End;
End;
Procedure SkipHead(var P: Pai);
Var OldP: Pai;
Begin
Repeat
OldP := P;
If (P^.typ in SkipInstr) Or
((P^.typ = ait_marker) And
(Pai_Marker(P)^.Kind = AsmBlockEnd)) Then
GetNextInstruction(P, P)
Else If ((P^.Typ = Ait_Marker) And
(Pai_Marker(P)^.Kind = NoPropInfoStart)) Then
{a marker of the NoPropInfoStart can't be the first instruction of a
paasmoutput list}
GetNextInstruction(Pai(P^.Previous),P);
{ If (P^.Typ = Ait_Marker) And
(Pai_Marker(P)^.Kind = AsmBlockStart) Then
Begin
P := Pai(P^.Next);
While (P^.typ <> Ait_Marker) Or
(Pai_Marker(P)^.Kind <> AsmBlockEnd) Do
P := Pai(P^.Next)
End;}
Until P = OldP
End;
{******************* The Data Flow Analyzer functions ********************}
function regLoadedWithNewValue(reg: tregister; canDependOnPrevValue: boolean;
hp: pai): boolean;
{ assumes reg is a 32bit register }
var p: paicpu;
begin
p := paicpu(hp);
regLoadedWithNewValue :=
assigned(hp) and
(hp^.typ = ait_instruction) and
(((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
(Reg32(p^.oper[1].reg) = reg) and
(canDependOnPrevValue or
(p^.oper[0].typ <> top_ref) or
not regInRef(reg,p^.oper[0].ref^)) or
((p^.opcode = A_POP) and
(Reg32(p^.oper[0].reg) = reg)));
end;
Procedure UpdateUsedRegs(Var UsedRegs: TRegSet; p: Pai);
{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
Not(Pai_Label(p)^.l^.is_used))) Do
p := Pai(p^.next);
While Assigned(p) And
(p^.typ=ait_RegAlloc) Do
Begin
if pairegalloc(p)^.allocation then
UsedRegs := UsedRegs + [PaiRegAlloc(p)^.Reg]
else
UsedRegs := UsedRegs - [PaiRegAlloc(p)^.Reg];
p := pai(p^.next);
End;
Until Not(Assigned(p)) Or
(Not(p^.typ in SkipInstr) And
Not((p^.typ = ait_label) And
Not(Pai_Label(p)^.l^.is_used)));
End;
Procedure IncState(Var S: Byte);
{Increases S by 1, wraps around at $ffff to 0 (so we won't get overflow
errors}
Begin
If (s <> $ff)
Then Inc(s)
Else s := 0
End;
Function RegInSequence(Reg: TRegister; Const Content: TContent): Boolean;
{checks the whole sequence of Content (so StartMod and and the next NrOfMods
Pai objects) to see whether Reg is used somewhere, without it being loaded
with something else first}
Var p: Pai;
Counter: Byte;
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
((Paicpu(p)^.opcode = A_MOV) or
(Paicpu(p)^.opcode = A_MOVZX) or
(Paicpu(p)^.opcode = A_MOVSX))
Then
Begin
If (Paicpu(p)^.oper[0].typ = top_ref) Then
With Paicpu(p)^.oper[0].ref^ Do
If (Base = procinfo^.FramePointer) And
(Index = R_NO)
Then
Begin
RegsChecked := RegsChecked + [Reg32(Paicpu(p)^.oper[1].reg)];
If Reg = Reg32(Paicpu(p)^.oper[1].reg) Then
Break;
End
Else
Begin
If (Base = Reg) And
Not(Base In RegsChecked)
Then TmpResult := True;
If Not(TmpResult) And
(Index = Reg) And
Not(Index In RegsChecked)
Then TmpResult := True;
End
End
Else TmpResult := RegInInstruction(Reg, p);
Inc(Counter);
GetNextInstruction(p,p)
End;
RegInSequence := TmpResult
End;
Procedure DestroyReg(p1: PPaiProp; Reg: TRegister; doIncState:Boolean);
{Destroys the contents of the register Reg in the PPaiProp 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 (ie. this register holds the contents of a variable and the value
of the variable in memory is changed }
Var TmpWState, TmpRState: Byte;
Counter: TRegister;
Begin
Reg := Reg32(Reg);
NrOfInstrSinceLastMod[Reg] := 0;
If (Reg >= R_EAX) And (Reg <= R_EDI)
Then
Begin
With p1^.Regs[Reg] Do
Begin
if doIncState then
IncState(WState);
TmpWState := WState;
TmpRState := RState;
FillChar(p1^.Regs[Reg], SizeOf(TContent), 0);
WState := TmpWState;
RState := TmpRState;
End;
For Counter := R_EAX to R_EDI Do
With p1^.Regs[Counter] Do
If (Typ = Con_Ref) And
RegInSequence(Reg, p1^.Regs[Counter])
Then
Begin
if doIncState then
IncState(WState);
TmpWState := WState;
TmpRState := RState;
FillChar(p1^.Regs[Counter], SizeOf(TContent), 0);
WState := TmpWState;
RState := TmpRState;
End;
End;
End;
{Procedure AddRegsToSet(p: Pai; Var RegSet: TRegSet);
Begin
If (p^.typ = ait_instruction) Then
Begin
Case Paicpu(p)^.oper[0].typ Of
top_reg:
If Not(Paicpu(p)^.oper[0].reg in [R_NO,R_ESP,procinfo^.FramePointer]) Then
RegSet := RegSet + [Paicpu(p)^.oper[0].reg];
top_ref:
With TReference(Paicpu(p)^.oper[0]^) Do
Begin
If Not(Base in [procinfo^.FramePointer,R_NO,R_ESP])
Then RegSet := RegSet + [Base];
If Not(Index in [procinfo^.FramePointer,R_NO,R_ESP])
Then RegSet := RegSet + [Index];
End;
End;
Case Paicpu(p)^.oper[1].typ Of
top_reg:
If Not(Paicpu(p)^.oper[1].reg in [R_NO,R_ESP,procinfo^.FramePointer]) Then
If RegSet := RegSet + [TRegister(TwoWords(Paicpu(p)^.oper[1]).Word1];
top_ref:
With TReference(Paicpu(p)^.oper[1]^) Do
Begin
If Not(Base in [procinfo^.FramePointer,R_NO,R_ESP])
Then RegSet := RegSet + [Base];
If Not(Index in [procinfo^.FramePointer,R_NO,R_ESP])
Then RegSet := RegSet + [Index];
End;
End;
End;
End;}
Function OpsEquivalent(const o1, o2: toper; Var RegInfo: TRegInfo; 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, RegInfo, OpAct);
Top_Ref:
OpsEquivalent := RefsEquivalent(o1.ref^, o2.ref^, RegInfo, OpAct);
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_Symbol :
OpsEqual:=(o1.sym=o2.sym) and (o1.symofs=o2.symofs);
Top_None :
OpsEqual := True
End;
End;
Function InstructionsEquivalent(p1, p2: Pai; Var RegInfo: TRegInfo): Boolean;
{$ifdef csdebug}
var hp: pai;
{$endif csdebug}
Begin {checks whether two Paicpu instructions are equal}
If Assigned(p1) And Assigned(p2) And
(Pai(p1)^.typ = ait_instruction) And
(Pai(p1)^.typ = ait_instruction) And
(Paicpu(p1)^.opcode = Paicpu(p2)^.opcode) And
(Paicpu(p1)^.oper[0].typ = Paicpu(p2)^.oper[0].typ) And
(Paicpu(p1)^.oper[1].typ = Paicpu(p2)^.oper[1].typ) And
(Paicpu(p1)^.oper[2].typ = Paicpu(p2)^.oper[2].typ)
Then
{both instructions have the same structure:
"<operator> <operand of type1>, <operand of type 2>"}
If ((Paicpu(p1)^.opcode = A_MOV) or
(Paicpu(p1)^.opcode = A_MOVZX) or
(Paicpu(p1)^.opcode = A_MOVSX)) And
(Paicpu(p1)^.oper[0].typ = top_ref) {then .oper[1]t = top_reg} Then
If Not(RegInRef(Paicpu(p1)^.oper[1].reg, Paicpu(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(Paicpu(p2)^.oper[1].reg, Paicpu(p2)^.oper[0].ref^)) And
RefsEqual(Paicpu(p1)^.oper[0].ref^, Paicpu(p2)^.oper[0].ref^)
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 Paicpu(p2)^.oper[0].ref^ Do
Begin
If Not(Base in [procinfo^.FramePointer, R_NO, R_ESP])
{it won't do any harm if the register is already in RegsLoadedForRef}
Then RegInfo.RegsLoadedForRef := RegInfo.RegsLoadedForRef + [Base];
If Not(Index in [procinfo^.FramePointer, R_NO, R_ESP])
Then RegInfo.RegsLoadedForRef := RegInfo.RegsLoadedForRef + [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(Paicpu(p1)^.oper[0], RegInfo);
{the registers from .oper[1] have to be equivalent, but not necessarily equal}
InstructionsEquivalent :=
RegsEquivalent(Paicpu(p1)^.oper[1].reg, Paicpu(p2)^.oper[1].reg, 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 Paicpu(p2)^.oper[0].ref^ Do
Begin
If Not(Base in [procinfo^.FramePointer,
Reg32(Paicpu(p2)^.oper[1].reg),R_NO,R_ESP])
{it won't do any harm if the register is already in RegsLoadedForRef}
Then
Begin
RegInfo.RegsLoadedForRef := RegInfo.RegsLoadedForRef + [Base];
{$ifdef csdebug}
Writeln(att_reg2str[base], ' added');
{$endif csdebug}
end;
If Not(Index in [procinfo^.FramePointer,
Reg32(Paicpu(p2)^.oper[1].reg),R_NO,R_ESP])
Then
Begin
RegInfo.RegsLoadedForRef := RegInfo.RegsLoadedForRef + [Index];
{$ifdef csdebug}
Writeln(att_reg2str[index], ' added');
{$endif csdebug}
end;
End;
If Not(Reg32(Paicpu(p2)^.oper[1].reg) In [procinfo^.FramePointer,R_NO,R_ESP])
Then
Begin
RegInfo.RegsLoadedForRef := RegInfo.RegsLoadedForRef -
[Reg32(Paicpu(p2)^.oper[1].reg)];
{$ifdef csdebug}
Writeln(att_reg2str[Reg32(Paicpu(p2)^.oper[1].reg)], ' removed');
{$endif csdebug}
end;
InstructionsEquivalent :=
OpsEquivalent(Paicpu(p1)^.oper[0], Paicpu(p2)^.oper[0], RegInfo, OpAct_Read) And
OpsEquivalent(Paicpu(p1)^.oper[1], Paicpu(p2)^.oper[1], RegInfo, OpAct_Write)
End
Else
{an instruction <> mov, movzx, movsx}
begin
{$ifdef csdebug}
hp := new(pai_asm_comment,init(strpnew('checking if equivalent')));
hp^.previous := p2;
hp^.next := p2^.next;
p2^.next^.previous := hp;
p2^.next := hp;
{$endif csdebug}
InstructionsEquivalent :=
OpsEquivalent(Paicpu(p1)^.oper[0], Paicpu(p2)^.oper[0], RegInfo, OpAct_Unknown) And
OpsEquivalent(Paicpu(p1)^.oper[1], Paicpu(p2)^.oper[1], RegInfo, OpAct_Unknown) And
OpsEquivalent(Paicpu(p1)^.oper[2], Paicpu(p2)^.oper[2], RegInfo, OpAct_Unknown)
end
{the instructions haven't even got the same structure, so they're certainly
not equivalent}
Else
begin
{$ifdef csdebug}
hp := new(pai_asm_comment,init(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 := new(pai_asm_comment,init(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: Pai): Boolean;
Begin {checks whether two Paicpu instructions are equal}
InstructionsEqual :=
Assigned(p1) And Assigned(p2) And
((Pai(p1)^.typ = ait_instruction) And
(Pai(p1)^.typ = ait_instruction) And
(Paicpu(p1)^.opcode = Paicpu(p2)^.opcode) And
(Paicpu(p1)^.oper[0].typ = Paicpu(p2)^.oper[0].typ) And
(Paicpu(p1)^.oper[1].typ = Paicpu(p2)^.oper[1].typ) And
OpsEqual(Paicpu(p1)^.oper[0].typ, Paicpu(p1)^.oper[0], Paicpu(p2)^.oper[0]) And
OpsEqual(Paicpu(p1)^.oper[1].typ, Paicpu(p1)^.oper[1], Paicpu(p2)^.oper[1]))
End;
*)
Procedure ReadReg(p: PPaiProp; Reg: TRegister);
Begin
Reg := Reg32(Reg);
If Reg in [R_EAX..R_EDI] Then
IncState(p^.Regs[Reg].RState)
End;
Procedure ReadRef(p: PPaiProp; Ref: PReference);
Begin
If Ref^.Base <> R_NO Then
ReadReg(p, Ref^.Base);
If Ref^.Index <> R_NO Then
ReadReg(p, Ref^.Index);
End;
Procedure ReadOp(P: PPaiProp;const o:toper);
Begin
Case o.typ Of
top_reg: ReadReg(P, o.reg);
top_ref: ReadRef(P, o.ref);
top_symbol : ;
End;
End;
Function RefInInstruction(Const Ref: TReference; p: Pai;
RefsEq: TRefCompare): Boolean;
{checks whehter Ref is used in P}
Var TmpResult: Boolean;
Begin
TmpResult := False;
If (p^.typ = ait_instruction) Then
Begin
If (Paicpu(p)^.oper[0].typ = Top_Ref) Then
TmpResult := RefsEq(Ref, Paicpu(p)^.oper[0].ref^);
If Not(TmpResult) And (Paicpu(p)^.oper[1].typ = Top_Ref) Then
TmpResult := RefsEq(Ref, Paicpu(p)^.oper[1].ref^);
If Not(TmpResult) And (Paicpu(p)^.oper[2].typ = Top_Ref) Then
TmpResult := RefsEq(Ref, Paicpu(p)^.oper[2].ref^);
End;
RefInInstruction := TmpResult;
End;
Function RefInSequence(Const Ref: TReference; Content: TContent;
RefsEq: TRefCompare): Boolean;
{checks the whole sequence of Content (so StartMod and and the next NrOfMods
Pai objects) to see whether Ref is used somewhere}
Var p: Pai;
Counter: Byte;
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)
Then TmpResult := True;
Inc(Counter);
GetNextInstruction(p,p)
End;
RefInSequence := TmpResult
End;
Function ArrayRefsEq(const r1, r2: TReference): Boolean;{$ifdef tp}far;{$endif}
Begin
ArrayRefsEq := (R1.Offset+R1.OffsetFixup = R2.Offset+R2.OffsetFixup) And
(R1.Segment = R2.Segment) And
(R1.Symbol=R2.Symbol) And
((Assigned(R1.Symbol)) Or
(R1.Base = R2.Base))
End;
Procedure DestroyRefs(p: pai; Const Ref: TReference; WhichReg: TRegister);
{destroys all registers which possibly contain a reference to Ref, WhichReg
is the register whose contents are being written to memory (if this proc
is called because of a "mov?? %reg, (mem)" instruction)}
Var RefsEq: TRefCompare;
Counter: TRegister;
Begin
WhichReg := Reg32(WhichReg);
If (Ref.base = procinfo^.FramePointer) or
Assigned(Ref.Symbol) Then
Begin
If (Ref.Index = R_NO) And
(Not(Assigned(Ref.Symbol)) or
(Ref.base = R_NO)) Then
{ local variable which is not an array }
RefsEq := {$ifdef fpc}@{$endif}RefsEqual
Else
{ local variable which is an array }
RefsEq := {$ifdef fpc}@{$endif}ArrayRefsEq;
{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
pointer based on Ref)
* with uncertain optimizations off:
- also destroy registers that contain any pointer}
For Counter := R_EAX to R_EDI Do
With PPaiProp(p^.OptInfo)^.Regs[Counter] Do
Begin
If (typ = Con_Ref) And
((Not(cs_UncertainOpts in aktglobalswitches) And
(NrOfMods <> 1)
) Or
(RefInSequence(Ref,PPaiProp(p^.OptInfo)^.Regs[Counter],RefsEq) And
((Counter <> WhichReg) Or
((NrOfMods <> 1) And
{StarMod is always of the type ait_instruction}
(Paicpu(StartMod)^.oper[0].typ = top_ref) And
RefsEq(Paicpu(StartMod)^.oper[0].ref^, Ref)
)
)
)
)
Then
DestroyReg(PPaiProp(p^.OptInfo), Counter, false)
End
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
}
For Counter := R_EAX to R_EDI Do
With PPaiProp(p^.OptInfo)^.Regs[Counter] Do
If (typ = Con_Ref) And
(Not(cs_UncertainOpts in aktglobalswitches) Or
{for movsl}
(Ref.Base = R_EDI) Or
{don't destroy if reg contains a parameter, local or global variable}
Not((NrOfMods = 1) And
(Paicpu(StartMod)^.oper[0].typ = top_ref) And
((Paicpu(StartMod)^.oper[0].ref^.base = procinfo^.FramePointer) Or
Assigned(Paicpu(StartMod)^.oper[0].ref^.Symbol)
)
)
)
Then DestroyReg(PPaiProp(p^.OptInfo), Counter, false)
End;
Procedure DestroyAllRegs(p: PPaiProp);
Var Counter: TRegister;
Begin {initializes/desrtoys all registers}
For Counter := R_EAX To R_EDI Do
Begin
ReadReg(p, Counter);
DestroyReg(p, Counter, true);
End;
p^.DirFlag := F_Unknown;
End;
Procedure DestroyOp(PaiObj: Pai; const o:Toper);
Begin
Case o.typ Of
top_reg: DestroyReg(PPaiProp(PaiObj^.OptInfo), o.reg, true);
top_ref:
Begin
ReadRef(PPaiProp(PaiObj^.OptInfo), o.ref);
DestroyRefs(PaiObj, o.ref^, R_NO);
End;
top_symbol:;
End;
End;
Function DFAPass1(AsmL: PAasmOutput; BlockStart: Pai): Pai;
{gathers the RegAlloc data... still need to think about where to store it to
avoid global vars}
Var BlockEnd: Pai;
Begin
BlockEnd := FindLoHiLabels(LoLab, HiLab, LabDif, BlockStart);
BuildLabelTableAndFixRegAlloc(AsmL, LTable, LoLab, LabDif, BlockStart, BlockEnd);
DFAPass1 := BlockEnd;
End;
{$ifdef arithopt}
Procedure AddInstr2RegContents({$ifdef statedebug} asml: paasmoutput; {$endif}
p: paicpu; reg: TRegister);
{$ifdef statedebug}
var hp: pai;
{$endif statedebug}
Begin
Reg := Reg32(Reg);
With PPaiProp(p^.optinfo)^.Regs[reg] Do
If (Typ = Con_Ref)
Then
Begin
IncState(WState);
{also store how many instructions are part of the sequence in the first
instructions PPaiProp, so it can be easily accessed from within
CheckSequence}
Inc(NrOfMods, NrOfInstrSinceLastMod[Reg]);
PPaiProp(Pai(StartMod)^.OptInfo)^.Regs[Reg].NrOfMods := NrOfMods;
NrOfInstrSinceLastMod[Reg] := 0;
{$ifdef StateDebug}
hp := new(pai_asm_comment,init(strpnew(att_reg2str[reg]+': '+tostr(PPaiProp(p^.optinfo)^.Regs[reg].WState)
+ ' -- ' + tostr(PPaiProp(p^.optinfo)^.Regs[reg].nrofmods))));
InsertLLItem(AsmL, p, p^.next, hp);
{$endif StateDebug}
End
Else
Begin
DestroyReg(PPaiProp(p^.optinfo), Reg, true);
{$ifdef StateDebug}
hp := new(pai_asm_comment,init(strpnew(att_reg2str[reg]+': '+tostr(PPaiProp(p^.optinfo)^.Regs[reg].WState))));
InsertLLItem(AsmL, p, p^.next, hp);
{$endif StateDebug}
End
End;
Procedure AddInstr2OpContents({$ifdef statedebug} asml: paasmoutput; {$endif}
p: paicpu; const oper: TOper);
Begin
If oper.typ = top_reg Then
AddInstr2RegContents({$ifdef statedebug} asml, {$endif}p, oper.reg)
Else
Begin
ReadOp(PPaiProp(p^.optinfo), oper);
DestroyOp(p, oper);
End
End;
{$endif arithopt}
Procedure DoDFAPass2(
{$Ifdef StateDebug}
AsmL: PAasmOutput;
{$endif statedebug}
BlockStart, BlockEnd: Pai);
{Analyzes the Data Flow of an assembler list. Starts creating the reg
contents for the instructions starting with p. Returns the last pai which has
been processed}
Var
CurProp: PPaiProp;
{$ifdef AnalyzeLoops}
TmpState: Byte;
{$endif AnalyzeLoops}
Cnt, InstrCnt : Longint;
InstrProp: TInsProp;
UsedRegs: TRegSet;
p, hp : Pai;
TmpRef: TReference;
TmpReg: TRegister;
Begin
p := BlockStart;
UsedRegs := [];
UpdateUsedregs(UsedRegs, p);
SkipHead(P);
BlockStart := p;
InstrCnt := 1;
FillChar(NrOfInstrSinceLastMod, SizeOf(NrOfInstrSinceLastMod), 0);
While (P <> BlockEnd) Do
Begin
{$IfDef TP}
New(CurProp);
{$Else TP}
CurProp := @PaiPropBlock^[InstrCnt];
{$EndIf TP}
If (p <> BlockStart)
Then
Begin
{$ifdef JumpAnal}
If (p^.Typ <> ait_label) Then
{$endif JumpAnal}
Begin
GetLastInstruction(p, hp);
CurProp^.Regs := PPaiProp(hp^.OptInfo)^.Regs;
CurProp^.DirFlag := PPaiProp(hp^.OptInfo)^.DirFlag;
End
End
Else
Begin
FillChar(CurProp^, SizeOf(CurProp^), 0);
{ For TmpReg := R_EAX to R_EDI Do
CurProp^.Regs[TmpReg].WState := 1;}
End;
CurProp^.UsedRegs := UsedRegs;
CurProp^.CanBeRemoved := False;
UpdateUsedRegs(UsedRegs, Pai(p^.Next));
{$ifdef TP}
PPaiProp(p^.OptInfo) := CurProp;
{$Endif TP}
For TmpReg := R_EAX To R_EDI Do
Inc(NrOfInstrSinceLastMod[TmpReg]);
Case p^.typ Of
ait_label:
{$Ifndef JumpAnal}
If (Pai_label(p)^.l^.is_used) Then
DestroyAllRegs(CurProp);
{$Else JumpAnal}
Begin
If (Pai_Label(p)^.is_used) Then
With LTable^[Pai_Label(p)^.l^.labelnr-LoLab] Do
{$IfDef AnalyzeLoops}
If (RefsFound = Pai_Label(p)^.l^.RefCount)
{$Else AnalyzeLoops}
If (JmpsProcessed = Pai_Label(p)^.l^.RefCount)
{$EndIf AnalyzeLoops}
Then
{all jumps to this label have been found}
{$IfDef AnalyzeLoops}
If (JmpsProcessed > 0)
Then
{$EndIf AnalyzeLoops}
{we've processed at least one jump to this label}
Begin
If (GetLastInstruction(p, hp) And
Not(((hp^.typ = ait_instruction)) And
(paicpu_labeled(hp)^.is_jmp))
Then
{previous instruction not a JMP -> the contents of the registers after the
previous intruction has been executed have to be taken into account as well}
For TmpReg := R_EAX to R_EDI Do
Begin
If (CurProp^.Regs[TmpReg].WState <>
PPaiProp(hp^.OptInfo)^.Regs[TmpReg].WState)
Then DestroyReg(CurProp, TmpReg, true)
End
End
{$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
(paicpu_labeled(hp)^.opcode = A_JMP))
Then
{previous instruction not a jmp, so keep all the registers' contents from the
previous instruction}
Begin
CurProp^.Regs := PPaiProp(hp^.OptInfo)^.Regs;
CurProp^.DirFlag := PPaiProp(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
(paicpu(hp)^.is_jmp) and
(pasmlabel(paicpu(hp)^.oper[0].sym)^.labelnr = Pai_Label(p)^.l^.labelnr)) And
Not((hp^.typ = ait_label) And
(LTable^[Pai_Label(hp)^.l^.labelnr-LoLab].RefsFound
= Pai_Label(hp)^.l^.RefCount) And
(LTable^[Pai_Label(hp)^.l^.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 := PaiPropBlock^[Cnt].Regs;
CurProp^.DirFlag := PaiPropBlock^[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 := PPaiProp(hp^.OptInfo)^.Regs;
CurProp^.DirFlag := PPaiProp(hp^.OptInfo)^.DirFlag;
DestroyAllRegs(PPaiProp(hp^.OptInfo))
End
End
{$EndIf AnalyzeLoops}
Else
{not all references to this label have been found, so destroy all registers}
Begin
GetLastInstruction(p, hp);
CurProp^.Regs := PPaiProp(hp^.OptInfo)^.Regs;
CurProp^.DirFlag := PPaiProp(hp^.OptInfo)^.DirFlag;
DestroyAllRegs(CurProp)
End;
End;
{$EndIf JumpAnal}
{$ifdef GDB}
ait_stabs, ait_stabn, ait_stab_function_name:;
{$endif GDB}
ait_align: ; { may destroy flags !!! }
ait_instruction:
Begin
if paicpu(p)^.is_jmp then
begin
{$IfNDef JumpAnal}
;
{$Else JumpAnal}
With LTable^[pasmlabel(paicpu(p)^.oper[0].sym)^.labelnr-LoLab] Do
If (RefsFound = pasmlabel(paicpu(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
PaiPropBlock^[InstrNr].Regs := CurProp^.Regs;
PaiPropBlock^[InstrNr].DirFlag := CurProp^.DirFlag;
Inc(JmpsProcessed);
End
Else
Begin
For TmpReg := R_EAX to R_EDI Do
If (PaiPropBlock^[InstrNr].Regs[TmpReg].WState <>
CurProp^.Regs[TmpReg].WState) Then
DestroyReg(@PaiPropBlock^[InstrNr], TmpReg, true);
Inc(JmpsProcessed);
End
{$ifdef AnalyzeLoops}
Else
{ backward jump, a loop for example}
{ If (JmpsProcessed > 0) Or
Not(GetLastInstruction(PaiObj, hp) And
(hp^.typ = ait_labeled_instruction) And
(paicpu_labeled(hp)^.opcode = A_JMP))
Then}
{instruction prior to label is not a jmp, or at least one jump to the label
has yet been processed}
Begin
Inc(JmpsProcessed);
For TmpReg := R_EAX to R_EDI Do
If (PaiPropBlock^[InstrNr].Regs[TmpReg].WState <>
CurProp^.Regs[TmpReg].WState)
Then
Begin
TmpState := PaiPropBlock^[InstrNr].Regs[TmpReg].WState;
Cnt := InstrNr;
While (TmpState = PaiPropBlock^[Cnt].Regs[TmpReg].WState) Do
Begin
DestroyReg(@PaiPropBlock^[Cnt], TmpReg, true);
Inc(Cnt);
End;
While (Cnt <= InstrCnt) Do
Begin
Inc(PaiPropBlock^[Cnt].Regs[TmpReg].WState);
Inc(Cnt)
End
End;
End
{ Else }
{instruction prior to label is a jmp and no jumps to the label have yet been
processed}
{ Begin
Inc(JmpsProcessed);
For TmpReg := R_EAX to R_EDI Do
Begin
TmpState := PaiPropBlock^[InstrNr].Regs[TmpReg].WState;
Cnt := InstrNr;
While (TmpState = PaiPropBlock^[Cnt].Regs[TmpReg].WState) Do
Begin
PaiPropBlock^[Cnt].Regs[TmpReg] := CurProp^.Regs[TmpReg];
Inc(Cnt);
End;
TmpState := PaiPropBlock^[InstrNr].Regs[TmpReg].WState;
While (TmpState = PaiPropBlock^[Cnt].Regs[TmpReg].WState) Do
Begin
DestroyReg(@PaiPropBlock^[Cnt], TmpReg, true);
Inc(Cnt);
End;
While (Cnt <= InstrCnt) Do
Begin
Inc(PaiPropBlock^[Cnt].Regs[TmpReg].WState);
Inc(Cnt)
End
End
End}
{$endif AnalyzeLoops}
End;
{$EndIf JumpAnal}
end
else
begin
InstrProp := InsProp[Paicpu(p)^.opcode];
Case Paicpu(p)^.opcode Of
A_MOV, A_MOVZX, A_MOVSX:
Begin
Case Paicpu(p)^.oper[0].typ Of
Top_Reg:
Case Paicpu(p)^.oper[1].typ Of
Top_Reg:
Begin
DestroyReg(CurProp, Paicpu(p)^.oper[1].reg, true);
ReadReg(CurProp, Paicpu(p)^.oper[0].reg);
{ CurProp^.Regs[Paicpu(p)^.oper[1].reg] :=
CurProp^.Regs[Paicpu(p)^.oper[0].reg];
If (CurProp^.Regs[Paicpu(p)^.oper[1].reg].ModReg = R_NO) Then
CurProp^.Regs[Paicpu(p)^.oper[1].reg].ModReg :=
Paicpu(p)^.oper[0].reg;}
End;
Top_Ref:
Begin
ReadReg(CurProp, Paicpu(p)^.oper[0].reg);
ReadRef(CurProp, Paicpu(p)^.oper[1].ref);
DestroyRefs(p, Paicpu(p)^.oper[1].ref^, Paicpu(p)^.oper[0].reg);
End;
End;
Top_Ref:
Begin {destination is always a register in this case}
ReadRef(CurProp, Paicpu(p)^.oper[0].ref);
ReadReg(CurProp, Paicpu(p)^.oper[1].reg);
TmpReg := Reg32(Paicpu(p)^.oper[1].reg);
If RegInRef(TmpReg, Paicpu(p)^.oper[0].ref^) And
(CurProp^.Regs[TmpReg].Typ = Con_Ref)
Then
Begin
With CurProp^.Regs[TmpReg] Do
Begin
IncState(WState);
{also store how many instructions are part of the sequence in the first
instructions PPaiProp, so it can be easily accessed from within
CheckSequence}
Inc(NrOfMods, NrOfInstrSinceLastMod[TmpReg]);
PPaiProp(Pai(StartMod)^.OptInfo)^.Regs[TmpReg].NrOfMods := NrOfMods;
NrOfInstrSinceLastMod[TmpReg] := 0;
End;
End
Else
Begin
DestroyReg(CurProp, TmpReg, true);
If Not(RegInRef(TmpReg, Paicpu(p)^.oper[0].ref^)) Then
With CurProp^.Regs[TmpReg] Do
Begin
Typ := Con_Ref;
StartMod := p;
NrOfMods := 1;
End
End;
{$ifdef StateDebug}
hp := new(pai_asm_comment,init(strpnew(att_reg2str[TmpReg]+': '+tostr(CurProp^.Regs[TmpReg].WState))));
InsertLLItem(AsmL, p, p^.next, hp);
{$endif StateDebug}
End;
top_symbol,Top_Const:
Begin
Case Paicpu(p)^.oper[1].typ Of
Top_Reg:
Begin
TmpReg := Reg32(Paicpu(p)^.oper[1].reg);
With CurProp^.Regs[TmpReg] Do
Begin
DestroyReg(CurProp, TmpReg, true);
typ := Con_Const;
StartMod := p;
End
End;
Top_Ref:
Begin
ReadRef(CurProp, Paicpu(p)^.oper[1].ref);
DestroyRefs(P, Paicpu(p)^.oper[1].ref^, R_NO);
End;
End;
End;
End;
End;
A_DIV, A_IDIV, A_MUL:
Begin
ReadOp(Curprop, Paicpu(p)^.oper[0]);
ReadReg(CurProp,R_EAX);
If (Paicpu(p)^.OpCode = A_IDIV) or
(Paicpu(p)^.OpCode = A_DIV) Then
ReadReg(CurProp,R_EDX);
DestroyReg(CurProp, R_EAX, true);
DestroyReg(CurProp, R_EDX, true)
End;
A_IMUL:
Begin
ReadOp(CurProp,Paicpu(p)^.oper[0]);
ReadOp(CurProp,Paicpu(p)^.oper[1]);
If (Paicpu(p)^.oper[2].typ = top_none) Then
If (Paicpu(p)^.oper[1].typ = top_none) Then
Begin
ReadReg(CurProp,R_EAX);
DestroyReg(CurProp, R_EAX, true);
DestroyReg(CurProp, R_EDX, true)
End
Else
{$ifdef arithopt}
AddInstr2OpContents(Paicpu(p), Paicpu(p)^.oper[1])
{$else arithopt}
DestroyOp(p, Paicpu(p)^.oper[1])
{$endif arithopt}
Else
{$ifdef arithopt}
AddInstr2OpContents(Paicpu(p), Paicpu(p)^.oper[2]);
{$else arithopt}
DestroyOp(p, Paicpu(p)^.oper[2]);
{$endif arithopt}
End;
{$ifdef arithopt}
A_LEA:
begin
readop(curprop,paicpu(p)^.oper[0]);
if reginref(paicpu(p)^.oper[1].reg,paicpu(p)^.oper[0].ref^) then
AddInstr2RegContents(paicpu(p), paicpu(p)^.oper[1].reg)
else destroyreg(curprop,paicpu(p)^.oper[1].reg,true);
end;
{$endif arithopt}
Else
Begin
Cnt := 1;
While (Cnt <= MaxCh) And
(InstrProp.Ch[Cnt] <> Ch_None) Do
Begin
Case InstrProp.Ch[Cnt] Of
Ch_REAX..Ch_REDI: ReadReg(CurProp,TCh2Reg(InstrProp.Ch[Cnt]));
Ch_WEAX..Ch_RWEDI:
Begin
If (InstrProp.Ch[Cnt] >= Ch_RWEAX) Then
ReadReg(CurProp, TCh2Reg(InstrProp.Ch[Cnt]));
DestroyReg(CurProp, TCh2Reg(InstrProp.Ch[Cnt]), true);
End;
{$ifdef arithopt}
Ch_MEAX..Ch_MEDI:
AddInstr2RegContents({$ifdef statedebug} asml, {$endif}
Paicpu(p),
TCh2Reg(InstrProp.Ch[Cnt]));
{$endif arithopt}
Ch_CDirFlag: CurProp^.DirFlag := F_NotSet;
Ch_SDirFlag: CurProp^.DirFlag := F_Set;
Ch_Rop1: ReadOp(CurProp, Paicpu(p)^.oper[0]);
Ch_Rop2: ReadOp(CurProp, Paicpu(p)^.oper[1]);
Ch_ROp3: ReadOp(CurProp, Paicpu(p)^.oper[2]);
Ch_Wop1..Ch_RWop1:
Begin
If (InstrProp.Ch[Cnt] in [Ch_RWop1]) Then
ReadOp(CurProp, Paicpu(p)^.oper[0]);
DestroyOp(p, Paicpu(p)^.oper[0]);
End;
{$ifdef arithopt}
Ch_Mop1:
AddInstr2OpContents({$ifdef statedebug} asml, {$endif}
Paicpu(p), Paicpu(p)^.oper[0]);
{$endif arithopt}
Ch_Wop2..Ch_RWop2:
Begin
If (InstrProp.Ch[Cnt] = Ch_RWop2) Then
ReadOp(CurProp, Paicpu(p)^.oper[1]);
DestroyOp(p, Paicpu(p)^.oper[1]);
End;
{$ifdef arithopt}
Ch_Mop2:
AddInstr2OpContents({$ifdef statedebug} asml, {$endif}
Paicpu(p), Paicpu(p)^.oper[1]);
{$endif arithopt}
Ch_WOp3..Ch_RWOp3:
Begin
If (InstrProp.Ch[Cnt] = Ch_RWOp3) Then
ReadOp(CurProp, Paicpu(p)^.oper[2]);
DestroyOp(p, Paicpu(p)^.oper[2]);
End;
{$ifdef arithopt}
Ch_Mop3:
AddInstr2OpContents({$ifdef statedebug} asml, {$endif}
Paicpu(p), Paicpu(p)^.oper[2]);
{$endif arithopt}
Ch_WMemEDI:
Begin
ReadReg(CurProp, R_EDI);
FillChar(TmpRef, SizeOf(TmpRef), 0);
TmpRef.Base := R_EDI;
DestroyRefs(p, TmpRef, R_NO)
End;
Ch_RFlags, Ch_WFlags, Ch_RWFlags, Ch_FPU:
Else
Begin
DestroyAllRegs(CurProp);
End;
End;
Inc(Cnt);
End
End;
end;
End;
End
Else
Begin
DestroyAllRegs(CurProp);
End;
End;
Inc(InstrCnt);
GetNextInstruction(p, p);
End;
End;
Function InitDFAPass2(BlockStart, BlockEnd: Pai): Boolean;
{reserves memory for the PPaiProps in one big memory block when not using
TP, returns False if not enough memory is available for the optimizer in all
cases}
Var p: Pai;
Count: Longint;
{ TmpStr: String; }
Begin
P := BlockStart;
SkipHead(P);
NrOfPaiObjs := 0;
While (P <> BlockEnd) Do
Begin
{$IfDef JumpAnal}
Case P^.Typ Of
ait_label:
Begin
If (Pai_Label(p)^.l^.is_used) Then
LTable^[Pai_Label(P)^.l^.labelnr-LoLab].InstrNr := NrOfPaiObjs
End;
ait_instruction:
begin
if paicpu(p)^.is_jmp then
begin
If (pasmlabel(paicpu(P)^.oper[0].sym)^.labelnr >= LoLab) And
(pasmlabel(paicpu(P)^.oper[0].sym)^.labelnr <= HiLab) Then
Inc(LTable^[pasmlabel(paicpu(P)^.oper[0].sym)^.labelnr-LoLab].RefsFound);
end;
end;
{ ait_instruction:
Begin
If (Paicpu(p)^.opcode = A_PUSH) And
(Paicpu(p)^.oper[0].typ = top_symbol) And
(PCSymbol(Paicpu(p)^.oper[0])^.offset = 0) Then
Begin
TmpStr := StrPas(PCSymbol(Paicpu(p)^.oper[0])^.symbol);
If}
End;
{$EndIf JumpAnal}
Inc(NrOfPaiObjs);
GetNextInstruction(p, p);
End;
{$IfDef TP}
If (MemAvail < (SizeOf(TPaiProp)*NrOfPaiObjs))
Or (NrOfPaiObjs = 0)
{this doesn't have to be one contiguous block}
Then InitDFAPass2 := False
Else InitDFAPass2 := True;
{$Else}
{Uncomment the next line to see how much memory the reloading optimizer needs}
{ Writeln((NrOfPaiObjs*(((SizeOf(TPaiProp)+3)div 4)*4)));}
{no need to check mem/maxavail, we've got as much virtual memory as we want}
If NrOfPaiObjs <> 0 Then
Begin
InitDFAPass2 := True;
GetMem(PaiPropBlock, NrOfPaiObjs*(((SizeOf(TPaiProp)+3)div 4)*4));
p := BlockStart;
SkipHead(p);
For Count := 1 To NrOfPaiObjs Do
Begin
PPaiProp(p^.OptInfo) := @PaiPropBlock^[Count];
GetNextInstruction(p, p);
End;
End
Else InitDFAPass2 := False;
{$EndIf TP}
End;
Function DFAPass2(
{$ifdef statedebug}
AsmL: PAasmOutPut;
{$endif statedebug}
BlockStart, BlockEnd: Pai): Boolean;
Begin
If InitDFAPass2(BlockStart, BlockEnd) Then
Begin
DoDFAPass2(
{$ifdef statedebug}
asml,
{$endif statedebug}
BlockStart, BlockEnd);
DFAPass2 := True
End
Else DFAPass2 := False;
End;
Procedure ShutDownDFA;
Begin
If LabDif <> 0 Then
FreeMem(LTable, LabDif*SizeOf(TLabelTableItem));
End;
End.
{
$Log$
Revision 1.84 2000-02-24 18:41:38 peter
* removed warnings/notes
Revision 1.83 2000/02/10 14:57:14 jonas
* fixed bug due to lack of support for top_symbol operands
Revision 1.82 2000/02/09 13:22:51 peter
* log truncated
Revision 1.81 2000/02/04 13:52:17 jonas
* better support for regvars (still needs a move of the call to the optimize
procedure to a place where resetusableregisters is not yet called to work)
* small regallocation fixes for -dnewoptimizations
Revision 1.80 2000/01/28 15:15:31 jonas
* moved skipinstr from daopt386 to aasm
* fixed crashing bug with -dreplacereg in csopt386.pas
Revision 1.79 2000/01/22 16:08:06 jonas
* better handling of exit(func_result) (no release of register that
holds the function result added)
* several other small improvements for reg allocation fixes
Revision 1.78 2000/01/13 13:07:06 jonas
* released -dalignreg
* some small fixes to -dnewOptimizations helper procedures
Revision 1.77 2000/01/09 01:44:21 jonas
+ (de)allocation info for EDI to fix reported bug on mailinglist.
Also some (de)allocation info for ESI added. Between -dallocEDI
because at this time of the night bugs could easily slip in ;)
Revision 1.76 2000/01/07 01:14:23 peter
* updated copyright to 2000
Revision 1.75 1999/12/05 16:48:43 jonas
* CSE of constant loading in regs works properly again
+ if a constant is stored into memory using "mov const, ref" and
there is a reg that contains this const, it is changed into
"mov reg, ref"
Revision 1.74 1999/12/02 11:26:41 peter
* newoptimizations define added
Revision 1.73 1999/11/27 23:45:43 jonas
* even more missing register deallocations are added!
Revision 1.72 1999/11/21 13:06:30 jonas
* improved fixing of missing regallocs (they're almost all correct
now!)
Revision 1.71 1999/11/20 12:50:32 jonas
* fixed small typo (C_M* -> Ch_M*) so -darithopt compiles again
Revision 1.70 1999/11/14 11:25:38 jonas
* fixed stupid typo in previous commit :(
Revision 1.69 1999/11/13 19:01:51 jonas
* div, idiv and mul destroy edx!!
Revision 1.68 1999/11/07 14:57:09 jonas
* much more complete/waterproof RegModifiedByInstruction()
Revision 1.67 1999/11/06 14:34:20 peter
* truncated log to 20 revs
Revision 1.66 1999/11/05 16:01:46 jonas
+ first implementation of choosing least used register for alignment code
(not yet working, between ifdef alignreg)
Revision 1.65 1999/10/27 16:11:28 peter
* insns.dat is used to generate all i386*.inc files
Revision 1.64 1999/10/23 14:44:24 jonas
* finally got around making GetNextInstruction return false when
the current pai object is a AsmBlockStart marker
* changed a loop in aopt386 which was incompatible with this change
Revision 1.63 1999/10/14 14:57:52 florian
- removed the hcodegen use in the new cg, use cgbase instead
Revision 1.62 1999/10/07 16:07:35 jonas
* small bugfix in ArrayRefsEq
}