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fpc/compiler/i386/csopt386.pas

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{
Copyright (c) 1998-2002 by Jonas Maebe, member of the Free Pascal
development team
This unit contains the common subexpression elimination procedure.
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 CSOpt386;
{$i fpcdefs.inc}
interface
uses aasmbase,aasmtai,aasmdata,aasmcpu, cpuinfo, cpubase, cgbase;
function CSE(asml: TAsmList; first, last: tai; pass: longint): boolean;
function doReplaceReg(hp: taicpu; newReg, orgReg: tsuperregister): boolean;
function changeOp(var o: toper; newReg, orgReg: tsuperregister): boolean;
function storeBack(start, current: tai; orgReg, newReg: tsuperregister): boolean;
function NoHardCodedRegs(p: taicpu; orgReg, newReg: tsuperregister): boolean;
function RegSizesOK(oldReg,newReg: tsuperregister; p: taicpu): boolean;
implementation
uses
{$ifdef csdebug}
cutils,
{$else}
{$ifdef replaceregdebug}cutils,{$endif}
{$endif}
globtype, verbose, procinfo, globals, daopt386, rgobj, rropt386,cgutils;
{
function TaiInSequence(P: tai; Const Seq: TContent): Boolean;
var P1: tai;
Counter: Byte;
TmpResult: Boolean;
begin
TmpResult := False;
P1 := Seq.StartMod;
Counter := 1;
while not(TmpResult) and
(Counter <= Seq.NrofMods) do
begin
if (P = P1) then TmpResult := True;
inc(Counter);
p1 := tai(p1.Next);
end;
TaiInSequence := TmpResult;
end;
}
function modifiesConflictingMemLocation(p1: tai; supreg: tsuperregister; c: tregContent;
var regsStillValid: tregset; onlymem: boolean; var invalsmemwrite: boolean): boolean;
var
p: taicpu;
tmpRef: treference;
regCounter: tsuperregister;
opCount: longint;
dummy: boolean;
begin
modifiesConflictingMemLocation := false;
invalsmemwrite := false;
if p1.typ <> ait_instruction then
exit;
p := taicpu(p1);
case p.opcode of
A_MOV,A_MOVSX,A_MOVZX:
if p.oper[1]^.typ = top_ref then
for regCounter := RS_EAX to RS_EDI do
begin
if (p.oper[0]^.typ<>top_reg) or
(getregtype(p.oper[0]^.reg) <> R_INTREGISTER) then
break;
if writeToMemDestroysContents(getsupreg(p.oper[0]^.reg),p.oper[1]^.ref^,
regCounter,topsize2tcgsize[p.opsize],c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
if (regcounter = supreg) then
invalsmemwrite := invalsmemwrite or dummy;
end
else
{ if is_reg_var[getsupreg(p.oper[1]^.reg)] then }
if not onlymem then
for regCounter := RS_EAX to RS_EDI do
begin
if writeDestroysContents(p.oper[1]^,regCounter,topsize2tcgsize[p.opsize],c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end
end;
A_DIV, A_IDIV, A_MUL, A_IMUL:
begin
if not onlymem then
if (p.ops = 1) then
begin
for regCounter := RS_EAX to RS_EDI do
begin
if writeToRegDestroysContents(RS_EDX,regCounter,c[regCounter]) then
begin
exclude(regsStillValid,RS_EDX);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
if writeToRegDestroysContents(RS_EAX,regCounter,c[regCounter]) then
begin
exclude(regsStillValid,RS_EAX);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
end
end
else
{ only possible for imul }
{ last operand is always destination }
for regCounter := RS_EAX to RS_EDI do
begin
if writeDestroysContents(p.oper[p.ops-1]^,regCounter,topsize2tcgsize[p.opsize],c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end
end
end;
else
for opCount := 1 to maxinschanges do
case InsProp[p.opcode].Ch[opCount] of
Ch_MOp1,CH_WOp1,CH_RWOp1:
if not(onlymem) or
(p.oper[0]^.typ = top_ref) then
{ or ((p.oper[0]^.typ = top_reg) and }
{ is_reg_var[getsupreg(p.oper[0]^.reg)]) then }
for regCounter := RS_EAX to RS_EDI do
begin
if writeDestroysContents(p.oper[0]^,regCounter,topsize2tcgsize[p.opsize],c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
if (regcounter = supreg) then
invalsmemwrite := invalsmemwrite or dummy;
end;
Ch_MOp2,CH_WOp2,CH_RWOp2:
if not(onlymem) or
(p.oper[1]^.typ = top_ref) then
{ or ((p.oper[1]^.typ = top_reg) and }
{ is_reg_var[getsupreg(p.oper[1]^.reg)]) then }
for regCounter := RS_EAX to RS_EDI do
begin
if writeDestroysContents(p.oper[1]^,regCounter,topsize2tcgsize[p.opsize],c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
if (regcounter = supreg) then
invalsmemwrite := invalsmemwrite or dummy;
end;
Ch_MOp3,CH_WOp3,CH_RWOp3:
if not(onlymem) or
(p.oper[2]^.typ = top_ref) then
{ or ((p.oper[2]^.typ = top_reg) and }
{ is_reg_var[getsupreg(p.oper[2]^.reg)]) then }
for regCounter := RS_EAX to RS_EDI do
begin
if writeDestroysContents(p.oper[2]^,regCounter,topsize2tcgsize[p.opsize],c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
if (regcounter = supreg) then
invalsmemwrite := invalsmemwrite or dummy;
end;
Ch_WMemEDI:
begin
fillchar(tmpref,sizeof(tmpref),0);
tmpRef.base := NR_EDI;
tmpRef.index := NR_EDI;
for regCounter := RS_EAX to RS_EDI do
begin
if writeToMemDestroysContents(RS_INVALID,tmpRef,regCounter,OS_32,c[regCounter],dummy) then
begin
exclude(regsStillValid,regCounter);
modifiesConflictingMemLocation := not(supreg in regsStillValid);
end;
if (regcounter = supreg) then
invalsmemwrite := invalsmemwrite or dummy;
end;
end;
end;
end;
end;
function isSimpleMemLoc(const ref: treference): boolean;
begin
{ isSimpleMemLoc :=
(ref.index = RS_NO) and
not(ref.base in (rg.usableregsint+[RS_EDI]));}
isSimpleMemLoc :=
(ref.index = NR_NO) and
((ref.base = NR_NO) or
not(getsupreg(ref.base) in [RS_EAX,RS_EBX,RS_ECX,RS_EDX,RS_ESI,RS_EDI]));
end;
{checks whether the current instruction sequence (starting with p) and the
one between StartMod and EndMod of Reg are the same. if so, the number of
instructions that match is stored in Found and true is returned, otherwise
Found holds the number of instructions between StartMod and EndMod and false
is returned}
function CheckSequence(p: tai; var prev: tai; supreg: tsuperregister; var Found: Longint;
var reginfo: toptreginfo; findPrevSeqs: boolean): Boolean;
var
regsNotRead, regsStillValid : tregset;
checkingPrevSequences,
passedFlagsModifyingInstr : boolean;
function getPrevSequence(p: tai; supreg: tsuperregister; currentPrev: tai; var newPrev: tai): tsuperregister;
const
current_reg: tsuperregister = RS_INVALID;
function stillValid(p: tai): boolean;
var
hp: tai;
begin
{ only regvars are still used at jump instructions }
if (cs_opt_regvar in current_settings.optimizerswitches) and
(p.typ = ait_instruction) and
taicpu(p).is_jmp then
regsstillvalid := regsstillvalid - ptaiprop(p.optinfo)^.usedregs;
stillValid :=
(p.typ = ait_instruction) and
(taicpu(p).opcode <> a_jmp) and
(ptaiprop(p.optinfo)^.regs[supreg].wstate =
ptaiprop(currentPrev.optinfo)^.regs[supreg].wstate) and
{ in case destroyreg is called with doIncState = false }
(ptaiprop(p.optinfo)^.regs[supreg].typ =
ptaiprop(currentPrev.optinfo)^.regs[supreg].typ) and
(supreg in (regsNotRead * regsStillValid));
{ stop if the register was still used right before a (conditional) }
{ jump, since in that case its current contents could still be }
{ used in the other path of the jump) }
if (p.typ = ait_instruction) and
(taicpu(p).is_jmp) and
getlastinstruction(p,hp) then
stillValid := stillValid and
not(supreg in ptaiprop(hp.optinfo)^.usedregs);
passedFlagsModifyingInstr := passedFlagsModifyingInstr or
instrWritesFlags(currentPrev);
end;
function findChangedRegister(p: tai): tsuperregister;
var
regCounter, loopstart: tsuperregister;
begin
if (current_reg <> RS_INVALID) then
loopstart := succ(current_reg)
else
loopstart := RS_EAX;
for regCounter := loopstart to RS_EDI do
with ptaiprop(p.optinfo)^.regs[regCounter] do
if ((startmod <>
ptaiprop(currentPrev.optinfo)^.regs[regCounter].startmod) or
(nrofMods <>
ptaiprop(currentPrev.optinfo)^.regs[regCounter].nrofMods)) and
(ptaiprop(p.optinfo)^.regs[regCounter].typ in [con_ref,con_noRemoveRef]) then
begin
findChangedRegister := regCounter;
current_reg := regCounter;
exit;
end;
current_reg := RS_INVALID;
findChangedRegister := RS_INVALID;
end;
var
hp, prevFound: tai;
tmpResult, regCounter: tsuperregister;
invalsmemwrite: boolean;
begin
if (current_reg <> RS_EDI) and
(current_reg <> RS_INVALID) then
begin
tmpResult := findChangedRegister(currentPrev);
if tmpResult <> RS_INVALID then
begin
getPrevSequence := tmpResult;
exit;
end;
end;
getPrevSequence := RS_INVALID;
passedFlagsModifyingInstr := passedFlagsModifyingInstr or
instrWritesFlags(currentPrev);
if (cs_opt_regvar in current_settings.optimizerswitches) and
(currentprev.typ = ait_instruction) and
taicpu(currentprev).is_jmp then
regsstillvalid := regsstillvalid - ptaiprop(currentprev.optinfo)^.usedregs;
if not getLastInstruction(currentPrev,hp) then
exit;
prevFound := currentPrev;
tmpResult := RS_INVALID;
while (tmpResult = RS_INVALID) and
stillValid(hp) and
(ptaiprop(prevFound.optinfo)^.canBeRemoved or
not(modifiesConflictingMemLocation(prevFound,supreg,
ptaiprop(p.optinfo)^.regs,regsStillValid,false, invalsmemwrite))) do
begin
{ only update the regsread for the instructions we already passed }
if not(ptaiprop(prevFound.optinfo)^.canBeRemoved) then
for regCounter := RS_EAX to RS_EDI do
if regReadByInstruction(regCounter,prevFound) then
exclude(regsNotRead,regCounter);
{ in case getPreviousInstruction fails and sets hp to nil in the }
{ next iteration }
prevFound := hp;
if not(ptaiprop(hp.optinfo)^.canBeRemoved) then
tmpResult := findChangedRegister(hp);
if not getLastInstruction(hp,hp) then
break;
end;
getPrevSequence := tmpResult;
if tmpResult <> RS_INVALID then
newPrev := prevFound;
end;
function getNextRegToTest(var prev: tai; currentReg: tsuperregister): tsuperregister;
begin
if not checkingPrevSequences then
begin
if (currentreg = RS_INVALID) then
currentreg := RS_EAX
else
inc(currentreg);
while (currentReg <= RS_EDI) and
not(ptaiprop(prev.optinfo)^.regs[currentReg].typ in [con_ref,con_noRemoveRef]) do
inc(currentReg);
if currentReg > RS_EDI then
begin
if (taicpu(p).oper[0]^.typ <> top_ref) or
isSimpleMemLoc(taicpu(p).oper[0]^.ref^) then
begin
checkingPrevSequences := true;
end
else
getNextRegToTest := RS_INVALID;
end
else
getNextRegToTest := currentReg;
end;
if checkingPrevSequences then
if findPrevSeqs then
getNextRegToTest :=
getPrevSequence(p,supreg,prev,prev)
else
getNextRegToTest := RS_INVALID;
end;
function changedreginvalidatedbetween(const oldreginfo: toptreginfo; var newreginfo: toptreginfo; startp,endp,current: tai): boolean;
var
orgdiffregs,diffregs: tregset;
runner: tai;
invalsmemwrite: boolean;
begin
diffregs := newreginfo.newregsencountered - oldreginfo.newregsencountered;
orgdiffregs := diffregs;
if diffregs <> [] then
begin
runner := startp;
repeat
modifiesConflictingMemLocation(runner,RS_EAX { dummy },ptaiprop(current.optinfo)^.regs,diffregs,true,invalsmemwrite);
if orgdiffregs <> diffregs then
begin
changedreginvalidatedbetween := true;
newreginfo := oldreginfo;
exit;
end;
getnextinstruction(runner,runner);
until (runner = endp);
end;
changedreginvalidatedbetween := false;
end;
var
prevreginfo: toptreginfo;
hp2, hp3{, EndMod}, prevhp3, highPrev, orgPrev, pprev: tai;
{Cnt,} OldNrofMods: Longint;
startRegInfo, OrgRegInfo, HighRegInfo: toptreginfo;
regModified, lastregloadremoved: array[RS_EAX..RS_ESP] of boolean;
HighFound, OrgRegFound: longint;
regcounter, regCounter2, tmpreg, base, index: tsuperregister;
OrgRegResult: Boolean;
TmpResult, flagResultsNeeded: Boolean;
begin {CheckSequence}
TmpResult := False;
FillChar(OrgRegInfo, Sizeof(OrgRegInfo), 0);
FillChar(startRegInfo, sizeof(startRegInfo), 0);
OrgRegFound := 0;
HighFound := 0;
OrgRegResult := False;
with startRegInfo do
begin
newRegsEncountered := [RS_EBP, RS_ESP];
fillword(new2oldreg,sizeof(new2oldreg),RS_INVALID);
new2OldReg[RS_EBP] := RS_EBP;
new2OldReg[RS_ESP] := RS_ESP;
oldRegsEncountered := newRegsEncountered;
end;
checkingPrevSequences := false;
passedFlagsModifyingInstr := false;
flagResultsNeeded := false;
regsNotRead := [RS_EAX,RS_EBX,RS_ECX,RS_EDX,RS_ESP,RS_EBP,RS_EDI,RS_ESI];
regsStillValid := regsNotRead;
GetLastInstruction(p, prev);
pprev := prev;
tmpreg:=RS_INVALID;
regCounter := getNextRegToTest(prev,tmpreg);
while (regcounter <> RS_INVALID) do
begin
fillchar(regModified,sizeof(regModified),0);
fillchar(lastregloadremoved,sizeof(lastregloadremoved),0);
reginfo := startRegInfo;
Found := 0;
hp2 := ptaiprop(prev.optinfo)^.Regs[regcounter].StartMod;
if (prev <> ptaiprop(prev.optinfo)^.Regs[regcounter].StartMod) then
OldNrofMods := ptaiprop(prev.optinfo)^.Regs[regcounter].NrofMods
else
OldNrofMods := 1;
hp3 := p;
if checkingprevsequences then
prevreginfo := reginfo;
while (Found <> OldNrofMods) and
{ old new }
InstructionsEquivalent(hp2, hp3, reginfo) and
(not(checkingprevsequences) or
not(changedreginvalidatedbetween(prevreginfo,reginfo,prev,p,hp3))) do
begin
if checkingprevsequences then
begin
prevreginfo := reginfo;
end;
if (hp3.typ = ait_instruction) and
((taicpu(hp3).opcode = A_MOV) or
(taicpu(hp3).opcode = A_MOVZX) or
(taicpu(hp3).opcode = A_LEA) or
(taicpu(hp3).opcode = A_MOVSX)) and
(taicpu(hp3).oper[1]^.typ = top_reg) and
not(regInOp(getsupreg(taicpu(hp3).oper[1]^.reg),taicpu(hp3).oper[0]^)) then
begin
tmpreg := getsupreg(taicpu(hp3).oper[1]^.reg);
lastregloadremoved[tmpreg] := ptaiprop(hp2.optinfo)^.canberemoved;
reginfo.lastReload[tmpreg] := hp3;
case taicpu(hp3).oper[0]^.typ of
top_ref:
begin
base := getsupreg(taicpu(hp3).oper[0]^.ref^.base);
index := getsupreg(taicpu(hp3).oper[0]^.ref^.index);
if (found <> 0) and
((taicpu(hp3).oper[0]^.ref^.base = NR_NO) or
regModified[base] or
(base = getsupreg(current_procinfo.framepointer))) and
((taicpu(hp3).oper[0]^.ref^.index = NR_NO) or
regModified[index]) and
not(regInRef(tmpReg,taicpu(hp3).oper[0]^.ref^)) then
begin
with ptaiprop(hp3.optinfo)^.regs[tmpreg] do
if nrofMods > (oldNrofMods - found) then
oldNrofMods := found + nrofMods;
{ next is safe because instructions are equivalent }
with ptaiprop(hp2.optinfo)^.regs[getsupreg(taicpu(hp2).oper[1]^.reg)] do
if nrofMods > (oldNrofMods - found) then
oldNrofMods := found + nrofMods;
end;
end;
top_reg:
if regModified[getsupreg(taicpu(hp3).oper[0]^.reg)] then
begin
with ptaiprop(hp3.optinfo)^.regs[tmpreg] do
if nrofMods > (oldNrofMods - found) then
oldNrofMods := found + nrofMods;
with ptaiprop(hp2.optinfo)^.regs[getsupreg(taicpu(hp2).oper[1]^.reg)] do
if nrofMods > (oldNrofMods - found) then
oldNrofMods := found + nrofMods;
end;
end;
end;
for regCounter2 := RS_EAX to RS_EDI do
regModified[regCounter2] := regModified[regCounter2] or
regModifiedByInstruction(regCounter2,hp3);
if flagResultsNeeded then
flagResultsNeeded := not instrReadsFlags(hp3);
if not flagResultsNeeded then
flagResultsNeeded := ptaiprop(hp3.optinfo)^.FlagsUsed;
inc(Found);
prevhp3 := hp3;
if (Found <> OldNrofMods) then
if not GetNextInstruction(hp2, hp2) or
not GetNextInstruction(hp3, hp3) then
break;
end;
if assigned(hp3) then
begin
prevhp3 := hp3;
getnextinstruction(hp3,hp3);
end;
if not assigned(hp3) or
{ a marker has no optinfo, which is used below }
(hp3.typ = ait_marker) then
hp3 := prevhp3;
{
a) movl -4(%ebp),%edx
movl -12(%ebp),%ecx
...
movl -8(%ebp),%eax
movl -12(%ebp),%edx (marked as removable)
movl (%eax,%edx),%eax (replaced by "movl (%eax,%ecx),%eax")
...
movl -8(%ebp),%eax
movl -12(%ebp),%edx
movl (%eax,%edx),%eax
movl (%edx),%edx
-> the "movl -12(ebp),%edx" can't be removed in the last sequence, because
edx has not been replaced with ecx there, and edx is still used after the
sequence
b) tests/webtbs/tw4266.pp
}
{ hp2 = instruction after previous sequence, pprev = instruction before }
{ current sequence, prev = instruction where the loads of the registers }
{ will be inserted }
for regCounter2 := RS_EAX to RS_EDI do
if (reginfo.new2OldReg[regCounter2] <> RS_INVALID) and
{ case a) above }
(((regCounter2 in ptaiprop(hp3.optinfo)^.usedRegs) and
(not regLoadedWithNewValue(regCounter2,false,hp3) and
lastregloadremoved[regcounter2])) or
{ case b) above }
((ptaiprop(hp2.optinfo)^.regs[regCounter2].wstate <>
ptaiprop(pprev.optinfo)^.regs[regcounter2].wstate)) or
((ptaiprop(hp2.optinfo)^.regs[reginfo.new2OldReg[regCounter2]].wstate <>
ptaiprop(prev.optinfo)^.regs[reginfo.new2OldReg[regCounter2]].wstate))) then
begin
found := 0;
break;
end;
if checkingPrevSequences then
begin
for regCounter2 := RS_EAX to RS_EDI do
if (reginfo.new2OldReg[regCounter2] <> RS_INVALID) and
(reginfo.new2OldReg[regCounter2] <> regCounter2) and
(not(regCounter2 in (regsNotRead * regsStillValid)) or
not(reginfo.new2OldReg[regCounter2] in regsStillValid)) then
begin
found := 0;
break;
end;
if passedFlagsModifyingInstr and flagResultsNeeded then
found := 0;
end;
TmpResult := true;
if (found <> OldNrofMods) then
TmpResult := false
else if assigned(hp3) then
for regcounter2 := RS_EAX to RS_EDI do
if (regcounter2 in reginfo.regsLoadedforRef) and
regModified[regcounter2] and
(regcounter2 in ptaiprop(hp3.optinfo)^.usedRegs) and
not regLoadedWithNewValue(regcounter2,false,hp3) then
begin
TmpResult := False;
if (found > 0) then
{this is correct because we only need to turn off the CanBeRemoved flag
when an instruction has already been processed by CheckSequence
(otherwise CanBeRemoved can't be true and thus can't have to be turned off).
if it has already been processed by CheckSequence and flagged to be
removed, it means that it has been checked against a previous sequence
and that it was equal (otherwise CheckSequence would have returned false
and the instruction wouldn't have been removed). if this "if found > 0"
check is left out, incorrect optimizations are performed.}
Found := ptaiprop(tai(p).optinfo)^.Regs[supreg].NrofMods;
break;
end;
if TmpResult and
(Found > HighFound) then
begin
highPrev := prev;
HighFound := Found;
HighRegInfo := reginfo;
end;
if (regcounter = supreg) then
begin
orgPrev := prev;
OrgRegFound := Found;
OrgRegResult := TmpResult;
OrgRegInfo := reginfo
end;
regCounter := getNextRegToTest(prev,regCounter);
end;
if (HighFound > 0) and
(not(OrgRegResult) Or
(HighFound > OrgRegFound))
then
begin
CheckSequence := True;
prev := highPrev;
reginfo := HighRegInfo;
Found := HighFound
end
else
begin
CheckSequence := OrgRegResult;
prev := orgPrev;
Found := OrgRegFound;
reginfo := OrgRegInfo;
end;
end; {CheckSequence}
procedure SetAlignReg(p: tai);
Const alignSearch = 12;
var regsUsable: TRegSet;
prevInstrCount, nextInstrCount: Longint;
prevState, nextWState,nextRState: Array[RS_EAX..RS_EDI] of byte;
regCounter, lastRemoved: tsuperregister;
prev, next: tai;
{$ifdef alignregdebug}
temp: tai;
{$endif alignregdebug}
begin
regsUsable := [RS_EAX,RS_ECX,RS_EDX,RS_EBX,{R_ESP,RS_EBP,}RS_ESI,RS_EDI];
for regCounter := RS_EAX to RS_EDI do
begin
prevState[regCounter] := ptaiprop(p.optinfo)^.Regs[regCounter].wState;
nextWState[regCounter] := ptaiprop(p.optinfo)^.Regs[regCounter].wState;
nextRState[regCounter] := ptaiprop(p.optinfo)^.Regs[regCounter].rState;
end;
getLastInstruction(p,prev);
getNextInstruction(p,next);
lastRemoved := getsupreg(tai_align(p).reg);
nextInstrCount := 0;
prevInstrCount := 0;
while ((assigned(prev) and
assigned(prev.optinfo) and
(prevInstrCount < alignSearch)) or
(assigned(next) and
assigned(next.optinfo) and
(nextInstrCount < alignSearch))) and
(regsUsable <> []) do
begin
{$ifdef alignregdebug}
if assigned(prev) then
begin
temp := tai_comment.Create(strpnew('got here'));
temp.next := prev.next;
temp.previous := prev;
prev.next := temp;
if assigned(temp.next) then
temp.next.previous := temp;
end;
{$endif alignregdebug}
if assigned(prev) and assigned(prev.optinfo) and
(prevInstrCount < alignSearch) then
begin
if (prev.typ = ait_instruction) and
(insProp[taicpu(prev).opcode].ch[1] <> Ch_ALL) and
(taicpu(prev).opcode <> A_JMP) then
begin
inc(prevInstrCount);
for regCounter := RS_EAX to RS_EDI do
begin
if (regCounter in regsUsable) and
(ptaiprop(prev.optinfo)^.Regs[regCounter].wState <>
prevState[regCounter]) then
begin
lastRemoved := regCounter;
exclude(regsUsable,regCounter);
{$ifdef alignregdebug}
temp := tai_comment.Create(strpnew(
std_regname(newreg(R_INTREGISTER,regCounter,R_SUBWHOLE))+' removed')));
temp.next := prev.next;
temp.previous := prev;
prev.next := temp;
if assigned(temp.next) then
temp.next.previous := temp;
if regsUsable = [] then
begin
temp := tai_comment.Create(strpnew(
'regsUsable empty here')));
temp.next := prev.next;
temp.previous := prev;
prev.next := temp;
if assigned(temp.next) then
temp.next.previous := temp;
end;
{$endif alignregdebug}
end;
prevState[regCounter] :=
ptaiprop(prev.optinfo)^.Regs[regCounter].wState;
end;
getLastInstruction(prev,prev);
end
else
if GetLastInstruction(prev,prev) and
assigned(prev.optinfo) then
for regCounter := RS_EAX to RS_EDI do
prevState[regCounter] :=
ptaiprop(prev.optinfo)^.Regs[regCounter].wState
end;
if assigned(next) and assigned(next.optinfo) and
(nextInstrCount < alignSearch) then
begin
if (next.typ = ait_instruction) and
(insProp[taicpu(next).opcode].ch[1] <> Ch_ALL) and
(taicpu(next).opcode <> A_JMP) then
begin
inc(nextInstrCount);
for regCounter := RS_EAX to RS_EDI do
begin
if (regCounter in regsUsable) and
((ptaiprop(next.optinfo)^.Regs[regCounter].wState <>
nextWState[regCounter]) or
(ptaiprop(next.optinfo)^.Regs[regCounter].rState <>
nextRState[regCounter])) then
begin
lastRemoved := regCounter;
exclude(regsUsable,regCounter);
{$ifdef alignregdebug}
temp := tai_comment.Create(strpnew(
std_regname(newreg(R_INTREGISTER,regCounter,R_SUBWHOLE))+' removed')));
temp.next := next.next;
temp.previous := next;
next.next := temp;
if assigned(temp.next) then
temp.next.previous := temp;
if regsUsable = [] then
begin
temp := tai_comment.Create(strpnew(
'regsUsable empty here')));
temp.next := next.next;
temp.previous := next;
next.next := temp;
if assigned(temp.next) then
temp.next.previous := temp;
end;
{$endif alignregdebug}
end;
nextWState[regCounter] :=
ptaiprop(next.optinfo)^.Regs[regCounter].wState;
nextRState[regCounter] :=
ptaiprop(next.optinfo)^.Regs[regCounter].rState;
end
end
else
for regCounter := RS_EAX to RS_EDI do
begin
nextWState[regCounter] :=
ptaiprop(next.optinfo)^.Regs[regCounter].wState;
nextRState[regCounter] :=
ptaiprop(next.optinfo)^.Regs[regCounter].rState;
end;
getNextInstruction(next,next);
end;
end;
if regsUsable <> [] then
for regCounter := RS_EAX to RS_EDI do
if regCounter in regsUsable then
begin
lastRemoved := regCounter;
break
end;
{$ifdef alignregdebug}
next := tai_comment.Create(strpnew(std_regname(newreg(R_INTREGISTER,lastremoved,R_SUBWHOLE))+
' chosen as alignment register')));
next.next := p.next;
next.previous := p;
p.next := next;
if assigned(next.next) then
next.next.previous := next;
{$endif alignregdebug}
tai_align(p).reg := newreg(R_INTREGISTER,lastRemoved,R_SUBWHOLE);
end;
procedure clearmemwrites(p: tai; supreg: tsuperregister);
var
beginmemwrite: tai;
begin
beginmemwrite := ptaiprop(p.optinfo)^.regs[supreg].memwrite;
repeat
ptaiprop(p.optinfo)^.regs[supreg].memwrite := nil;
until not getnextinstruction(p,p) or
(ptaiprop(p.optinfo)^.regs[supreg].memwrite <> beginmemwrite);
end;
procedure ClearRegContentsFrom(asml: TAsmList; supreg: tsuperregister; p, endP: tai);
{ first clears the contents of reg from p till endP. then the contents are }
{ cleared until the first instruction that changes reg }
var
{$ifdef replaceregdebug}
hp: tai;
l: longint;
{$endif replaceregdebug}
regcounter: tsuperregister;
oldStartmod: tai;
regstoclear: tregset;
begin
{$ifdef replaceregdebug}
l := random(1000);
hp := tai_comment.Create(strpnew(
'cleared '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+' from here... '+tostr(l)));
insertllitem(asml,p.previous,p,hp);
{$endif replaceregdebug}
ptaiprop(p.optinfo)^.Regs[supreg].typ := con_unknown;
regstoclear := [supreg];
while (p <> endP) do
begin
for regcounter := RS_EAX to RS_EDI do
begin
if (regcounter <> supreg) and
assigned(ptaiprop(p.optinfo)^.regs[supreg].memwrite) and
reginref(regcounter,ptaiprop(p.optinfo)^.regs[supreg].memwrite.oper[1]^.ref^) then
clearmemwrites(p,regcounter);
{ needs double loop to cheack for each dependency combination? }
if assigned(ptaiprop(p.optinfo)^.regs[regcounter].startmod) and
sequencedependsonreg(ptaiprop(p.optinfo)^.regs[regcounter],regcounter,supreg) then
include(regstoclear,regcounter);
if regcounter in regstoclear then
with ptaiprop(p.optinfo)^.Regs[regcounter] do
begin
typ := con_unknown;
memwrite := nil;
startmod := nil;
nrofmods := 0;
end;
end;
getNextInstruction(p,p);
end;
oldStartmod := ptaiprop(p.optinfo)^.Regs[supreg].startmod;
repeat
for regcounter := RS_EAX to RS_EDI do
begin
{ needs double loop to cheack for each dependency combination? }
if assigned(ptaiprop(p.optinfo)^.regs[regcounter].startmod) and
sequencedependsonreg(ptaiprop(p.optinfo)^.regs[regcounter],regcounter,supreg) then
include(regstoclear,regcounter);
with ptaiprop(p.optinfo)^.Regs[supreg] do
if regcounter in regstoclear then
begin
typ := con_unknown;
memwrite := nil;
end;
end;
until not getNextInstruction(p,p) or
(ptaiprop(p.optinfo)^.Regs[supreg].startmod <> oldStartmod);
{$ifdef replaceregdebug}
if assigned(p) then
begin
hp := tai_comment.Create(strpnew(
'cleared '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+' till here... '+tostr(l)));
insertllitem(asml,p.previous,p,hp);
end;
{$endif replaceregdebug}
end;
procedure RestoreRegContentsTo(asml: TAsmList; supreg: tsuperregister; const c: TContent; p, endP: tai);
var
{$ifdef replaceregdebug}
l: longint;
{$endif replaceregdebug}
hp: tai;
validregs, prevvalidregs: tregset;
regcounter: tsuperregister;
tmpState, newrstate: byte;
prevcontenttyp: byte;
memconflict: boolean;
invalsmemwrite: boolean;
begin
{$ifdef replaceregdebug}
l := random(1000);
hp := tai_comment.Create(strpnew(
'restored '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+' with data from here... '+tostr(l)));
insertllitem(asml,p.previous,p,hp);
{$endif replaceregdebug}
{ ptaiprop(p.optinfo)^.Regs[reg] := c;}
newrstate := c.rstate;
incstate(newrstate,$7f);
memconflict := false;
invalsmemwrite := false;
validregs := [RS_EAX..RS_EDI];
prevvalidregs := validregs;
while (p <> endP) and
not(memconflict) and
not(invalsmemwrite) do
begin
if not(ptaiprop(p.optinfo)^.canberemoved) and
regreadbyinstruction(supreg,p) then
incstate(newrstate,1);
// is this a write to memory that destroys the contents we are restoring?
memconflict := modifiesConflictingMemLocation(p,supreg,ptaiprop(p.optinfo)^.regs,validregs,false,invalsmemwrite);
if (validregs <> prevvalidregs) then
begin
prevvalidregs := validregs >< prevvalidregs;
for regcounter := RS_EAX to RS_EDI do
if regcounter in prevvalidregs then
clearRegContentsFrom(asml,regcounter,p,endP);
end;
prevvalidregs := validregs;
if (not memconflict and not invalsmemwrite) then
begin
ptaiprop(p.optinfo)^.Regs[supreg] := c;
ptaiprop(p.optinfo)^.Regs[supreg].rstate := newrstate;
end
else
begin
clearRegContentsFrom(asml,supreg,p,endP);
{$ifdef replaceregdebug}
if assigned(p) then
begin
hp := tai_comment.Create(strpnew(
'stopping restoring of '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+'because memory conflict... '+tostr(l)));
insertllitem(asml,p,p.next,hp);
end;
{$endif replaceregdebug}
exit
end;
getNextInstruction(p,p);
end;
tmpState := ptaiprop(p.optinfo)^.Regs[supreg].wState;
if (newrstate = ptaiprop(p.optinfo)^.Regs[supreg].rState) then
begin
incstate(ptaiprop(p.optinfo)^.regs[supreg].rstate,63);
if not getnextinstruction(p,hp) then
exit;
if (ptaiprop(hp.optinfo)^.regs[supreg].rstate = ptaiprop(p.optinfo)^.regs[supreg].rstate) then
internalerror(2004122710);
end;
repeat
newrstate := ptaiprop(p.optinfo)^.Regs[supreg].rState;
prevcontenttyp := ptaiprop(p.optinfo)^.Regs[supreg].typ;
// is this a write to memory that destroys the contents we are restoring?
memconflict := modifiesConflictingMemLocation(p,supreg,ptaiprop(p.optinfo)^.regs,validregs,false,invalsmemwrite);
if (validregs <> prevvalidregs) then
begin
prevvalidregs := validregs >< prevvalidregs;
for regcounter := RS_EAX to RS_EDI do
if regcounter in prevvalidregs then
clearRegContentsFrom(asml,regcounter,p,p);
end;
prevvalidregs := validregs;
if (not memconflict and not invalsmemwrite) then
begin
ptaiprop(p.optinfo)^.Regs[supreg] := c;
ptaiprop(p.optinfo)^.Regs[supreg].rstate := newrstate;
end;
until invalsmemwrite or
memconflict or
not getNextInstruction(p,p) or
(ptaiprop(p.optinfo)^.Regs[supreg].wState <> tmpState) or
(p.typ = ait_label) or
((prevcontenttyp <> con_invalid) and
(ptaiprop(p.optinfo)^.Regs[supreg].typ = con_invalid));
if assigned(p) and
(p.typ <> ait_marker) then
if ((p.typ = ait_label) or
memconflict or
invalsmemwrite) then
clearRegContentsFrom(asml,supreg,p,p)
else if (ptaiprop(p.optinfo)^.Regs[supreg].rstate = newrstate) then
incstate(ptaiprop(p.optinfo)^.Regs[supreg].rstate,20);
{$ifdef replaceregdebug}
if assigned(p) then
begin
hp := tai_comment.Create(strpnew(
'restored '+std_regname(newreg(R_INTREGISTER,supreg,R_SUBWHOLE))+' till here... '+tostr(l)));
insertllitem(asml,p,p.next,hp);
end;
{$endif replaceregdebug}
end;
function NoHardCodedRegs(p: taicpu; orgReg, newReg: tsuperregister): boolean;
var
chCount: byte;
begin
case p.opcode of
A_IMUL: noHardCodedRegs := p.ops <> 1;
A_SHL,A_SHR,A_ROR,A_ROL,A_SAR,A_SHLD,A_SHRD: noHardCodedRegs :=
(p.oper[0]^.typ <> top_reg) or
((orgReg <> RS_ECX) and (newReg <> RS_ECX));
else
begin
NoHardCodedRegs := true;
with InsProp[p.opcode] do
for chCount := 1 to maxinschanges do
if Ch[chCount] in ([Ch_REAX..Ch_MEDI,Ch_WMemEDI,Ch_All]-[Ch_RESP,Ch_WESP,Ch_RWESP]) then
begin
NoHardCodedRegs := false;
break
end;
end;
end;
end;
function ChangeReg(var Reg: TRegister; newReg, orgReg: tsuperregister): boolean;
begin
changereg := false;
if (reg <> NR_NO) and
(getregtype(reg) = R_INTREGISTER) and
(getsupreg(reg) = newreg) then
begin
changereg := true;
setsupreg(reg,orgreg);
end;
end;
function changeOp(var o: toper; newReg, orgReg: tsuperregister): boolean;
var
tmpresult: boolean;
begin
changeOp := false;
case o.typ of
top_reg: changeOp := changeReg(o.reg,newReg,orgReg);
top_ref:
begin
tmpresult := changeReg(o.ref^.base,newReg,orgReg);
changeop := changeReg(o.ref^.index,newReg,orgReg) or tmpresult;
end;
end;
end;
procedure updateStates(orgReg,newReg: tsuperregister; hp: tai; writeStateToo: boolean);
var
prev: tai;
newOrgRegRState, newOrgRegWState: byte;
begin
if getLastInstruction(hp,prev) then
with ptaiprop(prev.optinfo)^ do
begin
newOrgRegRState := byte(longint(regs[orgReg].rState) +
longint(ptaiprop(hp.optinfo)^.regs[newReg].rState) - regs[newReg].rstate);
if writeStateToo then
newOrgRegWState := byte(longint(regs[orgReg].wState) +
longint(ptaiprop(hp.optinfo)^.regs[newReg].wState) - regs[newReg].wstate);
end
else
with ptaiprop(hp.optinfo)^.regs[newReg] do
begin
newOrgRegRState := rState;
if writeStateToo then
newOrgRegWState := wState;
end;
with ptaiprop(hp.optinfo)^.regs[orgReg] do
begin
rState := newOrgRegRState;
if writeStateToo then
wState := newOrgRegwState;
end;
end;
function doReplaceReg(hp: taicpu; newReg, orgReg: tsuperregister): boolean;
var
opCount: longint;
tmpResult: boolean;
begin
tmpresult := false;
for opCount := 0 to hp.ops-1 do
tmpResult :=
changeOp(hp.oper[opCount]^,newReg,orgReg) or tmpResult;
doReplaceReg := tmpResult;
end;
function RegSizesOK(oldReg,newReg: tsuperregister; p: taicpu): boolean;
{ oldreg and newreg must be 32bit components }
var
opCount: longint;
tmpreg: tsuperregister;
begin
RegSizesOK := true;
{ if only one of them is a general purpose register ... }
if (IsGP32reg(oldReg) xor IsGP32Reg(newReg)) then
begin
for opCount := 0 to p.ops-1 do
if (p.oper[opCount]^.typ = top_reg) and
(getsubreg(p.oper[opCount]^.reg) in [R_SUBL,R_SUBH]) then
begin
tmpreg := getsupreg(p.oper[opCount]^.reg);
if (tmpreg = oldreg) or
(tmpreg = newreg) then
begin
RegSizesOK := false;
break
end
end;
end;
end;
function doReplaceReadReg(p: taicpu; newReg,orgReg: tsuperregister): boolean;
var
opCount: longint;
begin
doReplaceReadReg := false;
{ handle special case }
case p.opcode of
A_IMUL:
begin
case p.ops of
1: internalerror(1301001);
2,3:
begin
if changeOp(p.oper[0]^,newReg,orgReg) then
begin
{ updateStates(orgReg,newReg,p,false);}
doReplaceReadReg := true;
end;
if p.ops = 3 then
if changeOp(p.oper[1]^,newReg,orgReg) then
begin
{ updateStates(orgReg,newReg,p,false);}
doReplaceReadReg := true;
end;
end;
end;
end;
A_DIV,A_IDIV,A_MUL: internalerror(1301002);
else
begin
for opCount := 0 to p.ops-1 do
if p.oper[opCount]^.typ = top_ref then
if changeOp(p.oper[opCount]^,newReg,orgReg) then
begin
{ updateStates(orgReg,newReg,p,false);}
doReplaceReadReg := true;
end;
for opCount := 1 to maxinschanges do
case InsProp[p.opcode].Ch[opCount] of
Ch_ROp1:
if p.oper[0]^.typ = top_reg then
if changeReg(p.oper[0]^.reg,newReg,orgReg) then
begin
{ updateStates(orgReg,newReg,p,false);}
doReplaceReadReg := true;
end;
Ch_ROp2:
if p.oper[1]^.typ = top_reg then
if changeReg(p.oper[1]^.reg,newReg,orgReg) then
begin
{ updateStates(orgReg,newReg,p,false);}
doReplaceReadReg := true;
end;
Ch_ROp3:
if p.oper[2]^.typ = top_reg then
if changeReg(p.oper[2]^.reg,newReg,orgReg) then
begin
{ updateStates(orgReg,newReg,p,false);}
doReplaceReadReg := true;
end;
end;
end;
end;
end;
procedure updateState(supreg: tsuperregister; p: tai);
{ this procedure updates the read and write states of the instructions }
{ coming after p. It's called when the read/write state of p has been }
{ changed and this change has to be propagated to the following }
{ instructions as well }
var
newRState, newWState: byte;
prevRState, prevWState: byte;
doRState, doWState: boolean;
begin
{ get the new read/write states from p }
with ptaiprop(p.optinfo)^.regs[supreg] do
begin
newRState := rState;
newWState := wState;
end;
if not GetNextInstruction(p,p) then
exit;
{ get the old read/write states from the next instruction, to know }
{ when we can stop updating }
with ptaiprop(p.optinfo)^.regs[supreg] do
begin
prevRState := rState;
prevWState := wState;
end;
{ adjust the states if this next instruction reads/writes the register }
if regReadByInstruction(supreg,p) then
incState(newRState,1);
if regModifiedByInstruction(supreg,p) then
incState(newWState,1);
{ do we still have to update the read and/or write states? }
doRState := true;
doWState := true;
repeat
{ update the states }
with ptaiprop(p.optinfo)^.regs[supreg] do
begin
if doRState then
rState := newRState;
if doWState then
wState := newWState;
end;
if not getNextInstruction(p,p) then
break;
with ptaiprop(p.optinfo)^.regs[supreg] do
begin
{ stop updating the read state if it changes }
doRState :=
doRState and (rState = prevRState);
{ if, by accident, this changed state is the same as the one }
{ we've been using, change it to a value that's definitely }
{ different from the previous and next state }
if not doRState and
(rState = newRState) then
begin
incState(newRState,1);
prevRState := rState;
doRState := true;
end;
{ ditto for the write state }
doWState :=
doWState and (WState = prevWState);
if not doWState and
(wState = newWState) then
begin
incState(newWState,1);
prevWState := wState;
doWState := true;
end;
end;
{ stop when we don't have to update either state anymore }
until not(doRState or doWState);
end;
function storeBack(start, current: tai; orgReg, newReg: tsuperregister): boolean;
{ returns true if p1 contains an instruction that stores the contents }
{ of newReg back to orgReg }
begin
storeback := false;
if (current.typ = ait_instruction) and
(taicpu(current).opcode = A_MOV) and
(taicpu(current).oper[0]^.typ = top_reg) and
(getsupreg(taicpu(current).oper[0]^.reg) = newReg) and
(taicpu(current).oper[1]^.typ = top_reg) and
(getsupreg(taicpu(current).oper[1]^.reg) = orgReg) then
case taicpu(current).opsize of
S_B:
storeback := true;
S_W:
storeback := taicpu(start).opsize <> S_B;
S_L:
storeback := taicpu(start).opsize = S_L;
else
internalerror(2003121501);
end;
end;
function canreplacereg(orgsupreg, newsupreg: tsuperregister; p: tai;
orgRegCanBeModified: boolean; var resnewregmodified, resorgregread, resremovelast: boolean; var returnendp: tai): boolean;
var
endP, hp: tai;
removeLast, sequenceEnd, tmpResult, newRegModified, orgRegRead: boolean;
begin
canreplacereg := false;
tmpResult := true;
sequenceEnd := false;
newRegModified := false;
orgRegRead := false;
removeLast := false;
endP := p;
while tmpResult and not sequenceEnd do
begin
tmpResult :=
getNextInstruction(endP,endP) and
(endp.typ = ait_instruction) and
not(taicpu(endp).is_jmp);
if tmpresult and not assigned(endp.optinfo) then
begin
{ hp := tai_comment.Create(strpnew('next no optinfo'));
hp.next := endp;
hp.previous := endp.previous;
endp.previous := hp;
if assigned(hp.previous) then
hp.previous.next := hp;}
exit;
end;
if tmpResult and
{ don't take into account instructions that will be removed }
not (ptaiprop(endp.optinfo)^.canBeRemoved) then
begin
{ if the newsupreg gets stored back to the oldReg, we can change }
{ "mov %oldReg,%newReg; <operations on %newReg>; mov %newReg, }
{ %oldReg" to "<operations on %oldReg>" }
removeLast := storeBack(p,endP, orgsupreg, newsupreg);
sequenceEnd :=
{ no support for (i)div, mul and imul with hardcoded operands }
noHardCodedRegs(taicpu(endP),orgsupreg,newsupreg) and
{ if newsupreg gets loaded with a new value, we can stop }
{ replacing newsupreg with oldReg here (possibly keeping }
{ the original contents of oldReg so we still know them }
{ afterwards) }
(RegLoadedWithNewValue(newsupreg,true,taicpu(endP)) or
{ we can also stop if we reached the end of the use of }
{ newReg's current contents }
(GetNextInstruction(endp,hp) and
FindRegDealloc(newsupreg,hp)));
{ to be able to remove the first and last instruction of }
{ movl %reg1, %reg2 }
{ <operations on %reg2> (replacing reg2 with reg1 here) }
{ movl %reg2, %reg1 }
{ %reg2 must not be use afterwards (it can be as the }
{ result of a peepholeoptimization) }
removeLast := removeLast and sequenceEnd;
newRegModified :=
newRegModified or
(not(regLoadedWithNewValue(newsupreg,true,taicpu(endP))) and
RegModifiedByInstruction(newsupreg,endP));
orgRegRead := newRegModified and RegReadByInstruction(orgsupreg,endP);
sequenceEnd := SequenceEnd and
(removeLast or
{ since newsupreg will be replaced by orgsupreg, we can't allow that newsupreg }
{ gets modified if orgsupreg is still read afterwards (since after }
{ replacing, this would mean that orgsupreg first gets modified and then }
{ gets read in the assumption it still contains the unmodified value) }
not(newRegModified and orgRegRead)) (* and
{ since newsupreg will be replaced by orgsupreg, we can't allow that newsupreg }
{ gets modified if orgRegCanBeModified = false }
{ this now gets checked after the loop (JM) }
(orgRegCanBeModified or not(newRegModified)) *);
tmpResult :=
not(removeLast) and
not(newRegModified and orgRegRead) and
(* (orgRegCanBeModified or not(newRegModified)) and *)
(* already checked at the top
(endp.typ = ait_instruction) and *)
NoHardCodedRegs(taicpu(endP),orgsupreg,newsupreg) and
RegSizesOk(orgsupreg,newsupreg,taicpu(endP)) and
not RegModifiedByInstruction(orgsupreg,endP);
end;
end;
canreplacereg := sequenceEnd and
(removeLast or
(orgRegCanBeModified or not(newRegModified))) and
(not(assigned(endp)) or
not(endp.typ = ait_instruction) or
(noHardCodedRegs(taicpu(endP),orgsupreg,newsupreg) and
RegSizesOk(orgsupreg,newsupreg,taicpu(endP)) and
not(newRegModified and
(orgsupreg in ptaiprop(endp.optinfo)^.usedRegs) and
not(RegLoadedWithNewValue(orgsupreg,true,taicpu(endP))))));
if canreplacereg then
begin
resnewregmodified := newregmodified;
resorgregread := orgregread;
resremovelast := removelast;
end;
{ needed for replaceregdebug code }
returnendp := endp;
end;
function ReplaceReg(asml: TAsmList; orgsupreg, newsupreg: tsuperregister; p,
seqstart: tai; const c: TContent; orgRegCanBeModified: Boolean;
var returnEndP: tai): Boolean;
{ Tries to replace orgsupreg with newsupreg in all instructions coming after p }
{ until orgsupreg gets loaded with a new value. Returns true if successful, }
{ false otherwise. if successful, the contents of newsupreg are set to c, }
{ which should hold the contents of newsupreg before the current sequence }
{ started }
{ if the function returns true, returnEndP holds the last instruction }
{ where newsupreg was replaced by orgsupreg }
var
endP, hp: tai;
removeLast, newRegModified, orgRegRead,
stateChanged, readStateChanged: Boolean;
{$ifdef replaceregdebug}
l: longint;
{$endif replaceregdebug}
begin
replacereg := false;
if canreplacereg(orgsupreg,newsupreg,p,orgregcanbemodified,newregmodified, orgregread, removelast,endp) then
begin
{$ifdef replaceregdebug}
l := random(1000);
hp := tai_comment.Create(strpnew(
'replacing '+std_regname(newreg(R_INTREGISTER,newsupreg,R_SUBWHOLE))+' with '+std_regname(newreg(R_INTREGISTER,orgsupreg,R_SUBWHOLE))+
' from here... '+tostr(l)));
insertllitem(asml,p.previous,p,hp);
hp := tai_comment.Create(strpnew(
'replaced '+std_regname(newreg(R_INTREGISTER,newsupreg,R_SUBWHOLE))+' with '+std_regname(newreg(R_INTREGISTER,orgsupreg,R_SUBWHOLE))+
' till here ' + tostr(l)));
insertllitem(asml,endp,endp.next,hp);
{$endif replaceregdebug}
replaceReg := true;
returnEndP := endP;
if not getNextInstruction(p,hp) then
exit;
stateChanged := false;
while hp <> endP do
begin
if {not(ptaiprop(hp.optinfo)^.canBeRemoved) and }
(hp.typ = ait_instruction) then
stateChanged :=
doReplaceReg(taicpu(hp),newsupreg,orgsupreg) or stateChanged;
if stateChanged then
updateStates(orgsupreg,newsupreg,hp,true);
getNextInstruction(hp,hp)
end;
if assigned(endp) and (endp.typ = ait_instruction) then
readStateChanged :=
doReplaceReadReg(taicpu(endP),newsupreg,orgsupreg);
if stateChanged or readStateChanged then
updateStates(orgsupreg,newsupreg,endP,stateChanged);
if stateChanged or readStateChanged then
updateState(orgsupreg,endP);
{ We replaced newreg with oldreg between p and endp, so restore the contents }
{ of newreg there with its contents from before the sequence. }
if removeLast or
RegLoadedWithNewValue(newsupreg,true,endP) then
GetLastInstruction(endP,hp)
else hp := endP;
RestoreRegContentsTo(asml,newsupreg,c,seqstart,hp);
{ Ot is possible that the new register was modified (e.g. an add/sub), so if }
{ it was replaced by oldreg in that instruction, oldreg's contents have been }
{ changed. To take this into account, we simply set the contents of orgsupreg }
{ to "unknown" after this sequence }
if newRegModified then
ClearRegContentsFrom(asml,orgsupreg,p,hp);
if removeLast then
ptaiprop(endp.optinfo)^.canBeRemoved := true;
allocRegBetween(asml,newreg(R_INTREGISTER,orgsupreg,R_SUBWHOLE),p,endP,ptaiprop(p.optinfo)^.usedregs);
end
{$ifdef replaceregdebug}
else
begin
l := random(1000);
hp := tai_comment.Create(strpnew(
'replacing '+std_regname(newreg(R_INTREGISTER,newsupreg,R_SUBWHOLE))+' with '+std_regname(newreg(R_INTREGISTER,orgsupreg,R_SUBWHOLE))+
' from here... '+ tostr(l)));
insertllitem(asml,p.previous,p,hp);
hp := tai_comment.Create(strpnew(
'replacing '+std_regname(newreg(R_INTREGISTER,newsupreg,R_SUBWHOLE))+' with '+std_regname(newreg(R_INTREGISTER,orgsupreg,R_SUBWHOLE))+
' failed here ' + tostr(l)));
insertllitem(asml,endp,endp.next,hp);
end;
{$endif replaceregdebug}
end;
function FindRegWithConst(p: tai; size: topsize; l: aint; var Res: TRegister): Boolean;
{Finds a register which contains the constant l}
var
Counter: tsuperregister;
{$ifdef testing}
hp: tai;
{$endif testing}
begin
Result:=false;
Counter := RS_EAX;
repeat
{$ifdef testing}
if (ptaiprop(p.optinfo)^.regs[counter].typ in [con_const,con_noRemoveConst]) then
begin
hp := tai_comment.Create(strpnew(
'checking const load of '+tostr(l)+' here...'));
hp.next := ptaiprop(p.optinfo)^.Regs[Counter].StartMod;
hp.previous := ptaiprop(p.optinfo)^.Regs[Counter].StartMod^.previous;
ptaiprop(p.optinfo)^.Regs[Counter].StartMod^.previous := hp;
if assigned(hp.previous) then
hp.previous.next := hp;
end;
{$endif testing}
if (ptaiprop(p.optinfo)^.regs[counter].typ in [con_const,con_noRemoveConst]) and
(taicpu(ptaiprop(p.optinfo)^.Regs[Counter].StartMod).opsize = size) and
(taicpu(ptaiprop(p.optinfo)^.Regs[Counter].StartMod).oper[0]^.typ = top_const) and
(taicpu(ptaiprop(p.optinfo)^.Regs[Counter].StartMod).oper[0]^.val = l) then
begin
res:=taicpu(ptaiprop(p.optinfo)^.Regs[Counter].StartMod).oper[1]^.reg;
result:=true;
exit;
end;
inc(counter);
until (Counter > RS_EDI);
end;
procedure removePrevNotUsedLoad(asml: TAsmList; p: tai; supreg: tsuperregister; check: boolean);
{ if check = true, it means the procedure has to check whether it isn't }
{ possible that the contents are still used after p (used when removing }
{ instructions because of a "call"), otherwise this is not necessary }
{ (e.g. when you have a "mov 8(%ebp),%eax", you can be sure the previous }
{ value of %eax isn't used anymore later on) }
var
hp1, next, beforestartmod: tai;
begin
if getLastInstruction(p,hp1) then
with ptaiprop(hp1.optinfo)^.regs[supreg] do
if (typ in [con_ref,con_invalid,con_const]) and
(nrofMods = 1) and
(rState = ptaiprop(startmod.optinfo)^.regs[supreg].rState) and
(not(check) or
(not(regInInstruction(supreg,p)) and
(not(supreg in ptaiprop(hp1.optinfo)^.usedRegs) or
findRegDealloc(supreg,p)))) then
begin
ptaiprop(startMod.optinfo)^.canBeRemoved := true;
getnextinstruction(p,next);
{ give the register that was modified by this instruction again }
{ the contents it had before this instruction }
if getlastinstruction(startmod,beforestartmod) then
RestoreRegContentsTo(asml,supreg,ptaiprop(beforestartmod.optinfo)^.regs[supreg],
startmod,hp1)
else
ClearRegContentsFrom(asml,supreg,startmod,hp1);
end;
end;
{$ifdef notused}
function is_mov_for_div(p: taicpu): boolean;
begin
is_mov_for_div :=
(p.opcode = A_MOV) and
(p.oper[0]^.typ = top_const) and
(p.oper[1]^.typ = top_reg) and
(p.oper[1]^.reg = RS_EDX) and
getNextInstruction(p,p) and
(p.typ = ait_instruction) and
((p.opcode = A_DIV) or
(p.opcode = A_IDIV));
end;
{$endif notused}
function memtoreg(t: taicpu; const ref: treference; var startp: tai): tregister;
var
hp: tai;
p: ptaiprop;
regcounter: tsuperregister;
optimizable: boolean;
begin
if not getlastinstruction(t,hp) or
not issimplememloc(ref) then
begin
memtoreg := NR_NO;
exit;
end;
p := ptaiprop(hp.optinfo);
optimizable := false;
for regcounter := RS_EAX to RS_EDI do
begin
if (assigned(p^.regs[regcounter].memwrite) and
refsequal(ref,p^.regs[regcounter].memwrite.oper[1]^.ref^)) then
begin
optimizable := true;
hp := p^.regs[regcounter].memwrite;
end
else if ((p^.regs[regcounter].typ in [CON_REF,CON_NOREMOVEREF]) and
(p^.regs[regcounter].nrofmods = 1) and
((taicpu(p^.regs[regcounter].startmod).opcode = A_MOV) or
(taicpu(p^.regs[regcounter].startmod).opcode = A_MOVZX) or
(taicpu(p^.regs[regcounter].startmod).opcode = A_MOVSX)) and
(taicpu(p^.regs[regcounter].startmod).oper[0]^.typ = top_ref) and
refsequal(ref,taicpu(p^.regs[regcounter].startmod).oper[0]^.ref^)) then
begin
optimizable := true;
hp := p^.regs[regcounter].startmod;
end;
if optimizable then
if ((t.opsize <> S_B) or
not(regcounter in [RS_ESI,RS_EDI])) and
sizescompatible(taicpu(hp).opsize,t.opsize) then
begin
case t.opsize of
S_B:
begin
memtoreg := newreg(R_INTREGISTER,regcounter,R_SUBL)
end;
S_W,S_BW:
begin
memtoreg := newreg(R_INTREGISTER,regcounter,R_SUBW);
if (t.opsize = S_BW) then
begin
t.opcode := A_MOV;
t.opsize := S_W;
end;
end;
S_L,S_BL,S_WL:
begin
memtoreg := newreg(R_INTREGISTER,regcounter,R_SUBWHOLE);
if (t.opsize <> S_L) then
begin
t.opcode := A_MOV;
t.opsize := S_L;
end;
end;
end;
startp := hp;
exit;
end;
end;
memtoreg := NR_NO;
end;
procedure removeLocalStores(const t1: tai);
{var
p: tai;
regcount: tregister; }
begin
{
for regcount := LoGPReg to HiGPReg do
if assigned(pTaiProp(t1.optinfo)^.regs[regcount].memwrite) and
(taicpu(pTaiProp(t1.optinfo)^.regs[regcount].memwrite).oper[1]^.ref^.base
= current_procinfo.framepointer) then
begin
pTaiProp(pTaiProp(t1.optinfo)^.regs[regcount].memwrite.optinfo)^.canberemoved := true;
clearmemwrites(pTaiProp(t1.optinfo)^.regs[regcount].memwrite,regcount);
end;
}
end;
procedure loadcseregs(asml: TAsmList; const reginfo: toptreginfo; curseqend, prevseqstart, curseqstart, curprev: tai; cnt: longint);
var
regsloaded: tregset;
regloads, reguses: array[RS_EAX..RS_EDI] of tai;
regcounter: tsuperregister;
hp, hp2: tai;
insertpos, insertoptinfo, prevseq_next: tai;
i: longint;
opc: tasmop;
begin
regsloaded := [];
fillchar(regloads,sizeof(regloads),0);
fillchar(reguses,sizeof(reguses),0);
getnextinstruction(prevseqstart,prevseq_next);
for regcounter := RS_EAX To RS_EDI do
if (reginfo.new2oldreg[regcounter] <> RS_INVALID) Then
begin
include(regsloaded,regcounter);
if assigned(ptaiprop(prevseqstart.optinfo)^.Regs[reginfo.new2oldreg[regcounter]].StartMod) then
AllocRegBetween(asml,newreg(R_INTREGISTER,reginfo.new2oldreg[regcounter],R_SUBWHOLE),
ptaiprop(prevseqstart.optinfo)^.Regs[reginfo.new2oldreg[regcounter]].StartMod,curseqstart,
ptaiprop(ptaiprop(prevseqstart.optinfo)^.Regs[reginfo.new2oldreg[regcounter]].StartMod.optinfo)^.usedregs)
else
AllocRegBetween(asml,newreg(R_INTREGISTER,reginfo.new2oldreg[regcounter],R_SUBWHOLE),
prevseqstart,curseqstart,ptaiprop(prevseqstart.optinfo)^.usedregs);
if curprev <> prevseqstart then
begin
if assigned(reginfo.lastReload[regCounter]) then
getLastInstruction(reginfo.lastReload[regCounter],hp)
else if assigned(reginfo.lastReload[reginfo.new2oldreg[regCounter]]) then
getLastInstruction(reginfo.lastReload[reginfo.new2OldReg[regCounter]],hp)
else
hp := curprev;
clearRegContentsFrom(asml,regCounter,prevSeq_next,hp);
getnextInstruction(hp,hp);
allocRegBetween(asml,newreg(R_INTREGISTER,regCounter,R_SUBWHOLE),prevseqstart,hp,
ptaiprop(prevseqstart.optinfo)^.usedregs);
end;
if not(regcounter in reginfo.RegsLoadedforRef) and
{old reg new reg}
(reginfo.new2oldreg[regcounter] <> regcounter) then
begin
getLastInstruction(curseqend,hp);
opc := A_MOV;
insertpos := prevseq_next;
insertoptinfo := prevseqstart;
if assigned(reguses[regcounter]) then
if assigned(regloads[reginfo.new2oldreg[regcounter]]) then
opc := A_XCHG
else
begin
insertoptinfo := reguses[regcounter];
insertpos := tai(insertoptinfo.next)
end
else
if assigned(regloads[reginfo.new2oldreg[regcounter]]) then
begin
insertpos := regloads[reginfo.new2oldreg[regcounter]];
if not getlastinstruction(insertpos,insertoptinfo) then
internalerror(2006060701);
end;
hp := Tai_Marker.Create(mark_NoPropInfoStart);
InsertLLItem(asml, insertpos.previous,insertpos, hp);
hp2 := taicpu.Op_Reg_Reg(opc, S_L,
{old reg new reg}
newreg(R_INTREGISTER,reginfo.new2oldreg[regcounter],R_SUBWHOLE), newreg(R_INTREGISTER,regcounter,R_SUBWHOLE));
if (opc = A_XCHG) and
(taicpu(regloads[reginfo.new2oldreg[regcounter]]).opcode <> A_XCHG) then
begin
asml.remove(regloads[reginfo.new2oldreg[regcounter]]);
regloads[reginfo.new2oldreg[regcounter]].free;
regloads[reginfo.new2oldreg[regcounter]] := hp2;
reguses[regcounter] := hp2;
end;
regloads[regcounter] := hp2;
reguses[reginfo.new2oldreg[regcounter]] := hp2;
new(ptaiprop(hp2.optinfo));
ptaiprop(hp2.optinfo)^ := ptaiprop(insertoptinfo.optinfo)^;
ptaiprop(hp2.optinfo)^.canBeRemoved := false;
InsertLLItem(asml, insertpos.previous, insertpos, hp2);
hp := Tai_Marker.Create(mark_NoPropInfoEnd);
InsertLLItem(asml, insertpos.previous, insertpos, hp);
{ adjusts states in previous instruction so that it will }
{ definitely be different from the previous or next state }
incstate(ptaiprop(hp2.optinfo)^.
regs[reginfo.new2oldreg[regcounter]].rstate,20);
incstate(ptaiprop(hp2.optinfo)^.
regs[regCounter].wstate,20);
updateState(reginfo.new2oldreg[regcounter],hp2);
updateState(regcounter,hp2);
end
else
{ imagine the following code: }
{ normal wrong optimized }
{ movl 8(%ebp), %eax movl 8(%ebp), %eax }
{ movl (%eax), %eax movl (%eax), %eax }
{ cmpl 8(%ebp), %eax cmpl 8(%ebp), %eax }
{ jne l1 jne l1 }
{ movl 8(%ebp), %eax }
{ movl (%eax), %edi movl %eax, %edi }
{ movl %edi, -4(%ebp) movl %edi, -4(%ebp) }
{ movl 8(%ebp), %eax }
{ pushl 70(%eax) pushl 70(%eax) }
{ }
{ The error is that at the moment that the last instruction is executed, }
{ %eax doesn't contain 8(%ebp) anymore. Solution: the contents of }
{ registers that are completely removed from a sequence (= registers in }
{ RegLoadedforRef), have to be changed to their contents from before the }
{ sequence. }
{ if regcounter in reginfo.RegsLoadedforRef then }
begin
hp := curseqstart;
{ cnt still holds the number of instructions }
{ of the sequence, so go to the end of it }
for i := 1 to pred(cnt) do
getNextInstruction(hp,hp);
{ curprev = instruction prior to start of sequence }
restoreRegContentsTo(asml,regCounter,
ptaiprop(curprev.optinfo)^.Regs[regcounter],
curseqstart,hp);
end;
end;
end;
procedure replaceoperandwithreg(asml: TAsmList; p: tai; opnr: byte; reg: tregister);
var
hp: tai;
begin
{ new instruction -> it's info block is not in the big one allocated at the start }
hp := Tai_Marker.Create(mark_NoPropInfoStart);
InsertLLItem(asml, p.previous,p, hp);
{ duplicate the original instruction and replace it's designated operant with the register }
hp := tai(p.getcopy);
taicpu(hp).loadreg(opnr,reg);
{ add optimizer state info }
new(ptaiprop(hp.optinfo));
ptaiprop(hp.optinfo)^ := ptaiprop(p.optinfo)^;
{ new instruction can not be removed }
ptaiprop(hp.optinfo)^.canBeRemoved := false;
{ but the old one can }
ptaiprop(p.optinfo)^.canBeRemoved := true;
{ insert end marker }
InsertLLItem(asml, p.previous, p, hp);
hp := Tai_Marker.Create(mark_NoPropInfoEnd);
InsertLLItem(asml, p.previous, p, hp);
end;
procedure doCSE(asml: TAsmList; First, Last: tai; findPrevSeqs, doSubOpts: boolean);
{marks the instructions that can be removed by RemoveInstructs. They're not
removed immediately because sometimes an instruction needs to be checked in
two different sequences}
var cnt, cnt2, {cnt3,} orgNrofMods: longint;
p, hp1, hp2, prevSeq: tai;
hp4: tai;
hp5 : tai;
reginfo: toptreginfo;
memreg: tregister;
regcounter: tsuperregister;
begin
p := First;
SkipHead(p);
while (p <> Last) do
begin
case p.typ of
ait_align:
if not(tai_align(p).use_op) then
SetAlignReg(p);
ait_instruction:
begin
case taicpu(p).opcode of
{
Does not work anymore with register calling because the registers are
released before the call
A_CALL:
for regCounter := RS_EAX to RS_EBX do
removePrevNotUsedLoad(asml,p,regCounter,true);
}
A_CLD: if GetLastInstruction(p, hp1) and
(ptaiprop(hp1.optinfo)^.DirFlag = F_NotSet) then
ptaiprop(tai(p).optinfo)^.CanBeRemoved := True;
A_LEA, A_MOV, A_MOVZX, A_MOVSX:
begin
hp2 := p;
case taicpu(p).oper[0]^.typ of
top_ref, top_reg:
if (taicpu(p).oper[1]^.typ = top_reg) then
begin
With ptaiprop(p.optinfo)^.Regs[getsupreg(taicpu(p).oper[1]^.reg)] do
begin
if (startmod = p) then
orgNrofMods := nrofMods
else
orgNrofMods := 0;
if (p = StartMod) and
GetLastInstruction (p, hp1) and
not(hp1.typ in [ait_marker,ait_label]) then
{so we don't try to check a sequence when p is the first instruction of the block}
begin
{$ifdef csdebug}
hp5 := tai_comment.Create(strpnew(
'cse checking '+std_regname(taicpu(p).oper[1]^.reg)));
insertLLItem(asml,p,p.next,hp5);
{$endif csdebug}
if CheckSequence(p,prevSeq,getsupreg(taicpu(p).oper[1]^.reg), Cnt, reginfo, findPrevSeqs) and
(Cnt > 0) then
begin
(*
hp1 := nil;
{ although it's perfectly ok to remove an instruction which doesn't contain }
{ the register that we've just checked (CheckSequence takes care of that), }
{ the sequence containing this other register should also be completely }
{ checked and removed, otherwise we may get situations like this: }
{ }
{ movl 12(%ebp), %edx movl 12(%ebp), %edx }
{ movl 16(%ebp), %eax movl 16(%ebp), %eax }
{ movl 8(%edx), %edx movl 8(%edx), %edx }
{ movl (%eax), eax movl (%eax), eax }
{ cmpl %eax, %edx cmpl %eax, %edx }
{ jnz l123 getting converted to jnz l123 }
{ movl 12(%ebp), %edx movl 4(%eax), eax }
{ movl 16(%ebp), %eax }
{ movl 8(%edx), %edx }
{ movl 4(%eax), eax }
*)
{ not anymore: if the start of a new sequence is found while checking (e.g. }
{ above that of eax while checking edx, this new sequence is automatically }
{ also checked }
Cnt2 := 1;
while Cnt2 <= Cnt do
begin
{$ifndef noremove}
ptaiprop(p.optinfo)^.CanBeRemoved := True
{$endif noremove}
; inc(Cnt2);
GetNextInstruction(p, p);
end;
{hp4 is used to get the contents of the registers before the sequence}
GetLastInstruction(hp2, hp4);
{$IfDef CSDebug}
for regcounter := RS_EAX To RS_EDI do
if (regcounter in reginfo.RegsLoadedforRef) then
begin
hp5 := tai_comment.Create(strpnew('New: '+std_regname(newreg(R_INTREGISTER,regcounter,R_SUBNONE))+', Old: '+
std_regname(newreg(R_INTREGISTER,reginfo.new2oldreg[regcounter],R_SUBNONE))));
InsertLLItem(asml, tai(hp2.previous), hp2, hp5);
end;
{$EndIf CSDebug}
{ if some registers were different in the old and the new sequence, move }
{ the contents of those old registers to the new ones }
loadcseregs(asml,reginfo,p,prevseq,hp2,hp4,cnt);
continue;
end
end;
end;
{ try to replace the new reg with the old reg }
if not(ptaiprop(p.optinfo)^.canBeRemoved) then
if (taicpu(p).oper[0]^.typ = top_reg) and
(taicpu(p).oper[1]^.typ = top_reg) and
{ only remove if we're not storing something in a regvar }
(getsupreg(taicpu(p).oper[1]^.reg) in [RS_EAX,RS_EBX,RS_ECX,RS_EDX,RS_ESI,RS_EDI]) and
{ (taicpu(p).oper[1]^.reg in (rg.usableregsint+[RS_EDI])) and}
(taicpu(p).opcode = A_MOV) and
getLastInstruction(p,hp4) and
{ we only have to start replacing from the instruction after the mov, }
{ but replacereg only starts with getnextinstruction(p,p) }
replaceReg(asml,getsupreg(taicpu(p).oper[0]^.reg),
getsupreg(taicpu(p).oper[1]^.reg),p,p,
ptaiprop(hp4.optinfo)^.regs[getsupreg(taicpu(p).oper[1]^.reg)],false,hp1) then
begin
ptaiprop(p.optinfo)^.canBeRemoved := true;
{ this is just a regular move that was here, so the source register should be }
{ allocated already at this point -> only allocate from here onwards }
if not(getsupreg(taicpu(p).oper[0]^.reg) in pTaiProp(p.optinfo)^.usedregs) then
internalerror(2004101011);
allocRegBetween(asml,taicpu(p).oper[0]^.reg,
p,hp1,pTaiProp(p.optinfo)^.usedregs)
end
else
begin
if (taicpu(p).oper[1]^.typ = top_reg) and
not regInOp(getsupreg(taicpu(p).oper[1]^.reg),taicpu(p).oper[0]^) then
removePrevNotUsedLoad(asml,p,getsupreg(taicpu(p).oper[1]^.reg),false);
if doSubOpts and
(taicpu(p).opcode <> A_LEA) and
(taicpu(p).oper[0]^.typ = top_ref) then
begin
memreg :=
memtoreg(taicpu(p),
taicpu(p).oper[0]^.ref^,hp5);
if memreg <> NR_NO then
if (taicpu(p).opcode = A_MOV) and
(taicpu(p).oper[1]^.typ = top_reg) and
(taicpu(p).oper[1]^.reg = memreg) then
begin
pTaiProp(p.optinfo)^.canberemoved := true;
allocregbetween(asml,memreg,hp5,p,ptaiprop(hp5.optinfo)^.usedregs);
end
else
begin
replaceoperandwithreg(asml,p,0,memreg);
allocregbetween(asml,memreg,hp5,p,ptaiprop(hp5.optinfo)^.usedregs);
regcounter := getsupreg(memreg);
incstate(pTaiProp(p.optinfo)^.regs[regcounter].rstate,1);
updatestate(regcounter,p);
end;
end;
end;
{ at first, only try optimizations of large blocks, because doing }
{ doing smaller ones may prevent bigger ones from completing in }
{ in the next pass }
if not doSubOpts and (orgNrofMods <> 0) then
begin
p := hp2;
for cnt := 1 to pred(orgNrofMods) do
getNextInstruction(p,p);
end;
end;
top_Const:
begin
case taicpu(p).oper[1]^.typ of
Top_Reg:
begin
regCounter := getsupreg(taicpu(p).oper[1]^.reg);
if GetLastInstruction(p, hp1) then
With ptaiprop(hp1.optinfo)^.Regs[regCounter] do
if (typ in [con_const,con_noRemoveConst]) and
(taicpu(startMod).opsize >= taicpu(p).opsize) and
opsequal(taicpu(StartMod).oper[0]^,taicpu(p).oper[0]^) then
begin
ptaiprop(p.optinfo)^.CanBeRemoved := True;
allocRegBetween(asml,taicpu(p).oper[1]^.reg,startmod,p,
ptaiprop(startmod.optinfo)^.usedregs);
end
else
removePrevNotUsedLoad(asml,p,getsupreg(taicpu(p).oper[1]^.reg),false);
end;
Top_Ref:
if (taicpu(p).oper[0]^.typ = top_const) and
getLastInstruction(p,hp1) and
findRegWithConst(hp1,taicpu(p).opsize,taicpu(p).oper[0]^.val,memreg) then
begin
taicpu(p).loadreg(0,memreg);
{ mark the used register as read }
incstate(ptaiprop(p.optinfo)^.
regs[getsupreg(memreg)].rstate,20);
updateState(getsupreg(memreg),p);
allocRegBetween(asml,memreg,
ptaiprop(hp1.optinfo)^.regs[getsupreg(memreg)].startMod,p,
ptaiprop(ptaiprop(hp1.optinfo)^.regs[getsupreg(memreg)].startMod.optinfo)^.usedregs);
end;
end;
end;
end;
end;
A_LEAVE:
begin
if getlastinstruction(p,hp1) then
removeLocalStores(hp1);
end;
A_STD: if GetLastInstruction(p, hp1) and
(ptaiprop(hp1.optinfo)^.DirFlag = F_Set) then
ptaiprop(tai(p).optinfo)^.CanBeRemoved := True;
else
begin
for cnt := 1 to maxinschanges do
begin
case InsProp[taicpu(p).opcode].Ch[cnt] of
Ch_ROp1:
if (taicpu(p).oper[0]^.typ = top_ref) and
((taicpu(p).opcode < A_F2XM1) or
((taicpu(p).opcode > A_IN) and
(taicpu(p).opcode < A_OUT)) or
(taicpu(p).opcode = A_PUSH) or
((taicpu(p).opcode >= A_RCL) and
(taicpu(p).opcode <= A_XOR))) then
begin
memreg :=
memtoreg(taicpu(p),
taicpu(p).oper[0]^.ref^,hp5);
if memreg <> NR_NO then
begin
replaceoperandwithreg(asml,p,0,memreg);
allocregbetween(asml,memreg,hp5,p,ptaiprop(hp5.optinfo)^.usedregs);
regcounter := getsupreg(memreg);
incstate(pTaiProp(p.optinfo)^.regs[regcounter].rstate,1);
updatestate(regcounter,p);
end;
end;
Ch_MOp1:
if not(cs_opt_size in current_settings.optimizerswitches) and
(taicpu(p).oper[0]^.typ = top_ref) then
begin
memreg :=
memtoreg(taicpu(p),
taicpu(p).oper[0]^.ref^,hp5);
if (memreg <> NR_NO) and
(not getNextInstruction(p,hp1) or
(RegLoadedWithNewValue(getsupreg(memreg),false,hp1) or
FindRegDealloc(getsupreg(memreg),hp1))) then
begin
hp1 := Tai_Marker.Create(mark_NoPropInfoEnd);
insertllitem(asml,p,p.next,hp1);
hp1 := taicpu.op_reg_ref(A_MOV,reg2opsize(memreg),
memreg,taicpu(p).oper[0]^.ref^);
new(ptaiprop(hp1.optinfo));
pTaiProp(hp1.optinfo)^ := pTaiProp(p.optinfo)^;
insertllitem(asml,p,p.next,hp1);
regcounter := getsupreg(memreg);
incstate(pTaiProp(hp1.optinfo)^.regs[regcounter].rstate,1);
updatestate(regcounter,hp1);
hp1 := Tai_Marker.Create(mark_NoPropInfoStart);
insertllitem(asml,p,p.next,hp1);
replaceoperandwithreg(asml,p,0,memreg);
allocregbetween(asml,memreg,hp5,
tai(p.next.next),ptaiprop(hp5.optinfo)^.usedregs);
ClearRegContentsFrom(asml,regcounter,hp5,p);
end;
end;
Ch_ROp2:
if ((taicpu(p).opcode = A_CMP) or
(taicpu(p).opcode = A_TEST)) and
(taicpu(p).oper[1]^.typ = top_ref) then
begin
memreg :=
memtoreg(taicpu(p),
taicpu(p).oper[1]^.ref^,hp5);
if memreg <> NR_NO then
begin
replaceoperandwithreg(asml,p,1,memreg);
allocregbetween(asml,memreg,hp5,p,ptaiprop(hp5.optinfo)^.usedregs);
regcounter := getsupreg(memreg);
incstate(pTaiProp(p.optinfo)^.regs[regcounter].rstate,1);
updatestate(regcounter,p);
end;
end;
Ch_MOp2:
if not(cs_opt_size in current_settings.optimizerswitches) and
(taicpu(p).oper[1]^.typ = top_ref) and
((taicpu(p).opcode < A_BT) or
((taicpu(p).opcode > A_IN) and
(taicpu(p).opcode < A_OUT)) or
(taicpu(p).opcode = A_PUSH) or
((taicpu(p).opcode >= A_RCL) and
(taicpu(p).opcode <= A_XOR))) then
begin
memreg :=
memtoreg(taicpu(p),
taicpu(p).oper[1]^.ref^,hp5);
if (memreg <> NR_NO) and
(not getNextInstruction(p,hp1) or
(RegLoadedWithNewValue(getsupreg(memreg),false,hp1) or
FindRegDealloc(getsupreg(memreg),hp1))) then
begin
hp1 := Tai_Marker.Create(mark_NoPropInfoEnd);
insertllitem(asml,p,p.next,hp1);
hp1 := taicpu.op_reg_ref(A_MOV,reg2opsize(memreg),
memreg,taicpu(p).oper[1]^.ref^);
new(ptaiprop(hp1.optinfo));
pTaiProp(hp1.optinfo)^ := pTaiProp(p.optinfo)^;
insertllitem(asml,p,p.next,hp1);
regcounter := getsupreg(memreg);
incstate(pTaiProp(hp1.optinfo)^.regs[regcounter].rstate,1);
updatestate(regcounter,hp1);
hp1 := Tai_Marker.Create(mark_NoPropInfoStart);
insertllitem(asml,p,p.next,hp1);
replaceoperandwithreg(asml,p,1,memreg);
allocregbetween(asml,memreg,hp5,
tai(p.next.next),ptaiprop(hp5.optinfo)^.usedregs);
ClearRegContentsFrom(asml,regcounter,hp5,p);
end;
end;
end;
end;
end;
end
end;
end;
GetNextInstruction(p, p);
end;
end;
function removeInstructs(asml: TAsmList; first, last: tai): boolean;
{ Removes the marked instructions and disposes the PTaiProps of the other }
{ instructions }
var
p, hp1: tai;
nopropinfolevel: longint;
begin
removeInstructs := false;
p := First;
nopropinfolevel := 0;
while (p <> Last) do
begin
if (p.typ = ait_marker) and
(Tai_marker(p).kind = mark_NoPropInfoStart) then
begin
hp1 := tai(p.next);
asml.remove(p);
p.free;
nopropinfolevel := 1;
while (nopropinfolevel <> 0) do
begin
p := tai(hp1.next);
{$ifndef noinstremove}
{ allocregbetween can insert new ait_regalloc objects }
{ without optinfo }
if (hp1.typ = ait_marker) then
begin
case Tai_marker(hp1).kind of
{ they can be nested! }
mark_NoPropInfoStart: inc(nopropinfolevel);
mark_NoPropInfoEnd: dec(nopropinfolevel);
else
begin
hp1 := p;
continue;
end;
end;
asml.remove(hp1);
hp1.free;
end
else if assigned(hp1.optinfo) then
if ptaiprop(hp1.optinfo)^.canBeRemoved then
begin
dispose(ptaiprop(hp1.optinfo));
hp1.optinfo := nil;
asml.remove(hp1);
hp1.free;
end
else
{$endif noinstremove}
begin
dispose(ptaiprop(hp1.optinfo));
hp1.optinfo := nil;
end;
hp1 := p;
end;
end
else
{$ifndef noinstremove}
if assigned(p.optinfo) and
ptaiprop(p.optinfo)^.canBeRemoved then
begin
hp1 := tai(p.next);
asml.Remove(p);
p.free;
p := hp1;
removeInstructs := true;
end
else
{$endif noinstremove}
begin
p.optinfo := nil;
p := tai(p.next);
end;
end;
end;
function CSE(asml: TAsmList; First, Last: tai; pass: longint): boolean;
begin
doCSE(asml, First, Last, not(cs_opt_level3 in current_settings.optimizerswitches) or (pass >= 2),
not(cs_opt_level3 in current_settings.optimizerswitches) or (pass >= 1));
{ register renaming }
if not(cs_opt_level3 in current_settings.optimizerswitches) or (pass > 0) then
doRenaming(asml, first, last);
cse := removeInstructs(asml, first, last);
end;
end.
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