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* CSE of constant loading in regs works properly again

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+ 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"
This commit is contained in:
Jonas Maebe 1999-12-05 16:48:43 +00:00
parent 514f0f9879
commit 8272526892
3 changed files with 95 additions and 63 deletions
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66
compiler/csopt386.pas
View File

@ -486,7 +486,10 @@ begin
end;
Procedure ClearRegContentsFrom(reg: TRegister; p: pai);
var hp: pai;
var
{$ifdef replaceregdebug}
hp: pai;
{$endif replaceregdebug}
tmpState: byte;
begin
tmpState := PPaiProp(p^.optInfo)^.Regs[reg].wState;
@ -756,6 +759,39 @@ begin
End;
{$endif replacereg}
{$ifdef arithopt}
Function FindRegWithConst(p: Pai; size: topsize; l: longint; Var Res: TRegister): Boolean;
{Finds a register which contains the constant l}
Var Counter: TRegister;
{$ifdef testing}
hp: pai;
{$endif testing}
tmpresult: boolean;
Begin
Counter := R_NO;
repeat
inc(counter);
tmpresult := (PPaiProp(p^.OptInfo)^.Regs[Counter].Typ = Con_Const) and
(paicpu(PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod)^.opsize = size) and
(paicpu(PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod)^.oper[0].val = l);
{$ifdef testing}
if (PPaiProp(p^.OptInfo)^.Regs[Counter].Typ = Con_Const) then
begin
hp := new(pai_asm_comment,init(strpnew(
'checking const load of '+tostr(l)+' here...')));
hp^.next := PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod;
hp^.previous := PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod^.previous;
PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod^.previous := hp;
if assigned(hp^.previous) then
hp^.previous^.next := hp;
end;
{$endif testing}
until tmpresult or (Counter = R_EDI);
res := counter;
FindRegWithConst := tmpResult;
End;
{$endif arithopt}
Procedure DoCSE(AsmL: PAasmOutput; First, Last: Pai);
{marks the instructions that can be removed by RemoveInstructs. They're not
removed immediately because sometimes an instruction needs to be checked in
@ -980,10 +1016,16 @@ Begin
If GetLastInstruction(p, hp1) Then
With PPaiProp(hp1^.OptInfo)^.Regs[Reg32(Paicpu(p)^.oper[1].reg)] Do
If (Typ = Con_Const) And
(StartMod = p) Then
(paicpu(startMod)^.opsize >= paicpu(p)^.opsize) and
(paicpu(StartMod)^.oper[0].val = paicpu(p)^.oper[0].val) Then
PPaiProp(p^.OptInfo)^.CanBeRemoved := True;
End;
{ Top_Ref:;}
{$ifdef arithopt}
Top_Ref:
if getLastInstruction(p,hp1) and
findRegWithConst(hp1,paicpu(p)^.opsize,paicpu(p)^.oper[0].val,regCounter) then
paicpu(p)^.loadreg(0,regCounter);
{$endif arithopt}
End;
End;
End;
@ -991,16 +1033,6 @@ Begin
A_STD: If GetLastInstruction(p, hp1) And
(PPaiProp(hp1^.OptInfo)^.DirFlag = F_Set) Then
PPaiProp(Pai(p)^.OptInfo)^.CanBeRemoved := True;
A_XOR:
Begin
If (Paicpu(p)^.oper[0].typ = top_reg) And
(Paicpu(p)^.oper[0].typ = top_reg) And
(Paicpu(p)^.oper[1].reg = Paicpu(p)^.oper[1].reg) And
GetLastInstruction(p, hp1) And
(PPaiProp(hp1^.OptInfo)^.Regs[Reg32(Paicpu(p)^.oper[1].reg)].typ = con_const) And
(PPaiProp(hp1^.OptInfo)^.Regs[Reg32(Paicpu(p)^.oper[1].reg)].StartMod = nil)
Then PPaiProp(p^.OptInfo)^.CanBeRemoved := True
End
End
End;
End;
@ -1061,7 +1093,13 @@ End.
{
$Log$
Revision 1.35 1999-12-02 11:26:41 peter
Revision 1.36 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 1.35 1999/12/02 11:26:41 peter
* newoptimizations define added
Revision 1.34 1999/11/21 13:09:41 jonas

53
compiler/daopt386.pas
View File

@ -115,8 +115,7 @@ type
TContent = Packed Record
{start and end of block instructions that defines the
content of this register. If Typ = con_const, then
Longint(StartMod) = value of the constant)}
content of this register.}
StartMod: pai;
{starts at 0, gets increased everytime the register is written to}
WState: Byte;
@ -818,23 +817,6 @@ Begin
Not(Pai_Label(p)^.l^.is_used)));
End;
(*Function FindZeroreg(p: Pai; Var Result: TRegister): Boolean;
{Finds a register which contains the constant zero}
Var Counter: TRegister;
Begin
Counter := R_EAX;
FindZeroReg := True;
While (Counter <= R_EDI) And
((PPaiProp(p^.OptInfo)^.Regs[Counter].Typ <> Con_Const) or
(PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod <> Pointer(0))) Do
Inc(Byte(Counter));
If (PPaiProp(p^.OptInfo)^.Regs[Counter].Typ = Con_Const) And
(PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod = Pointer(0))
Then Result := Counter
Else FindZeroReg := False;
End;*)
Procedure IncState(Var S: Byte);
{Increases S by 1, wraps around at $ffff to 0 (so we won't get overflow
errors}
@ -1744,22 +1726,15 @@ Begin
DestroyOp(p, Paicpu(p)^.oper[2]);
{$endif arithopt}
End;
A_XOR:
Begin
ReadOp(CurProp, Paicpu(p)^.oper[0]);
ReadOp(CurProp, Paicpu(p)^.oper[1]);
If (Paicpu(p)^.oper[0].typ = top_reg) And
(Paicpu(p)^.oper[1].typ = top_reg) And
(Paicpu(p)^.oper[0].reg = Paicpu(p)^.oper[1].reg)
Then
Begin
DestroyReg(CurProp, Paicpu(p)^.oper[0].reg, true);
CurProp^.Regs[Reg32(Paicpu(p)^.oper[0].reg)].typ := Con_Const;
CurProp^.Regs[Reg32(Paicpu(p)^.oper[0].reg)].StartMod := Pointer(0)
End
Else
DestroyOp(p, Paicpu(p)^.oper[1]);
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;
@ -1943,7 +1918,13 @@ End.
{
$Log$
Revision 1.74 1999-12-02 11:26:41 peter
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

39
compiler/popt386.pas
View File

@ -1061,15 +1061,6 @@ Begin
Paicpu(p)^.LoadReg(1,Paicpu(hp1)^.oper[0].reg);
End
End;
{changes "mov $0, %reg" into "xor %reg, %reg"}
If (Paicpu(p)^.oper[0].typ = Top_Const) And
(Paicpu(p)^.oper[0].val = 0) And
(Paicpu(p)^.oper[1].typ = Top_Reg)
Then
Begin
Paicpu(p)^.opcode := A_XOR;
Paicpu(p)^.LoadReg(0,Paicpu(p)^.oper[1].reg);
End;
End;
A_MOVZX:
Begin
@ -1545,9 +1536,17 @@ Begin
End
End
Else
End;
A_XOR:
If (Paicpu(p)^.oper[0].typ = top_reg) And
(Paicpu(p)^.oper[1].typ = top_reg) And
(Paicpu(p)^.oper[0].reg = Paicpu(p)^.oper[1].reg) then
{ temporarily change this to 'mov reg,0' to make it easier }
{ for the CSE. Will be changed back in pass 2 }
begin
paicpu(p)^.opcode := A_MOV;
paicpu(p)^.loadconst(0,0);
end;
End;
end; { if is_jmp }
End;
@ -1674,8 +1673,16 @@ Begin
Dispose(hp2,Done);
p := hp1
End;
End;
End
{$endif foldArithOps}
else if (Paicpu(p)^.oper[0].typ = Top_Const) And
(Paicpu(p)^.oper[0].val = 0) And
(Paicpu(p)^.oper[1].typ = Top_Reg) Then
{ change "mov $0, %reg" into "xor %reg, %reg" }
Begin
Paicpu(p)^.opcode := A_XOR;
Paicpu(p)^.LoadReg(0,Paicpu(p)^.oper[1].reg);
End
End;
A_MOVZX:
Begin
@ -1735,7 +1742,13 @@ End.
{
$Log$
Revision 1.73 1999-12-02 11:26:41 peter
Revision 1.74 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 1.73 1999/12/02 11:26:41 peter
* newoptimizations define added
Revision 1.72 1999/11/30 10:40:45 peter