fpc/compiler/i386/popt386.pas
daniel 42c320cb29 * cs_regalloc renamed to cs_regvars to avoid confusion with register
allocator
  * Some preventive changes to i386 spillinh code
2003-08-09 18:56:54 +00:00

2224 lines
106 KiB
ObjectPascal

{
$Id$
Copyright (c) 1998-2002 by Florian Klaempfl and Jonas Maebe
This unit contains the peephole optimizer.
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 POpt386;
{$i fpcdefs.inc}
Interface
Uses Aasmbase,aasmtai,aasmcpu,verbose;
Procedure PrePeepHoleOpts(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
Procedure PeepHoleOptPass1(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
Procedure PeepHoleOptPass2(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
Procedure PostPeepHoleOpts(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
Implementation
Uses
globtype,systems,
globals,cgbase,
symsym,symdef,
{$ifdef finaldestdebug}
cobjects,
{$endif finaldestdebug}
cpuinfo,cpubase,DAOpt386,cginfo,rgobj;
Function RegUsedAfterInstruction(Reg: Tregister; p: Tai; Var UsedRegs: TRegSet): Boolean;
Begin
if reg.enum>lastreg then
internalerror(200301081);
reg := reg32(reg);
UpdateUsedRegs(UsedRegs, Tai(p.Next));
RegUsedAfterInstruction :=
(Reg.enum in UsedRegs) and
(not(getNextInstruction(p,p)) or
not(regLoadedWithNewValue(reg,false,p)));
End;
function doFpuLoadStoreOpt(asmL: TAAsmoutput; var p: Tai): boolean;
{ returns true if a "continue" should be done after this optimization }
var hp1, hp2: Tai;
begin
doFpuLoadStoreOpt := false;
if (Taicpu(p).oper[0].typ = top_ref) and
getNextInstruction(p, hp1) and
(hp1.typ = ait_instruction) and
(((Taicpu(hp1).opcode = A_FLD) and
(Taicpu(p).opcode = A_FSTP)) or
((Taicpu(p).opcode = A_FISTP) and
(Taicpu(hp1).opcode = A_FILD))) and
(Taicpu(hp1).oper[0].typ = top_ref) and
(Taicpu(hp1).opsize = Taicpu(p).opsize) and
refsEqual(Taicpu(p).oper[0].ref^, Taicpu(hp1).oper[0].ref^) then
begin
if getNextInstruction(hp1, hp2) and
(hp2.typ = ait_instruction) and
((Taicpu(hp2).opcode = A_LEAVE) or
(Taicpu(hp2).opcode = A_RET)) and
(Taicpu(p).oper[0].ref^.Base.enum = current_procinfo.FramePointer.enum) and
(Taicpu(p).oper[0].ref^.Offset >= tvarsym(current_procinfo.procdef.funcretsym).adjusted_address) and
(Taicpu(p).oper[0].ref^.Index.enum = R_NO) then
begin
asml.remove(p);
asml.remove(hp1);
p.free;
hp1.free;
p := hp2;
removeLastDeallocForFuncRes(asmL, p);
doFPULoadStoreOpt := true;
end
else
{ fst can't store an extended value! }
if (Taicpu(p).opsize <> S_FX) and
(Taicpu(p).opsize <> S_IQ) then
begin
if (Taicpu(p).opcode = A_FSTP) then
Taicpu(p).opcode := A_FST
else Taicpu(p).opcode := A_FIST;
asml.remove(hp1);
hp1.free;
end
end;
end;
Procedure PrePeepHoleOpts(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
var
p,hp1: Tai;
l: Aword;
tmpRef: treference;
Begin
P := BlockStart;
While (P <> BlockEnd) Do
Begin
Case p.Typ Of
Ait_Instruction:
Begin
Case Taicpu(p).opcode Of
A_IMUL:
{changes certain "imul const, %reg"'s to lea sequences}
Begin
If (Taicpu(p).oper[0].typ = Top_Const) And
(Taicpu(p).oper[1].typ = Top_Reg) And
(Taicpu(p).opsize = S_L) Then
If (Taicpu(p).oper[0].val = 1) Then
If (Taicpu(p).oper[2].typ = Top_None) Then
{remove "imul $1, reg"}
Begin
hp1 := Tai(p.Next);
asml.Remove(p);
p.free;
p := hp1;
Continue;
End
Else
{change "imul $1, reg1, reg2" to "mov reg1, reg2"}
Begin
hp1 := Taicpu.Op_Reg_Reg(A_MOV, S_L, Taicpu(p).oper[1].reg,Taicpu(p).oper[2].reg);
InsertLLItem(AsmL, p.previous, p.next, hp1);
p.free;
p := hp1;
End
Else If
((Taicpu(p).oper[2].typ = Top_Reg) or
(Taicpu(p).oper[2].typ = Top_None)) And
(aktoptprocessor < ClassP6) And
(Taicpu(p).oper[0].val <= 12) And
Not(CS_LittleSize in aktglobalswitches) And
(Not(GetNextInstruction(p, hp1)) Or
{GetNextInstruction(p, hp1) And}
Not((Tai(hp1).typ = ait_instruction) And
((Taicpu(hp1).opcode=A_Jcc) and
(Taicpu(hp1).condition in [C_O,C_NO]))))
Then
Begin
reference_reset_old(tmpref);
Case Taicpu(p).oper[0].val Of
3: Begin
{imul 3, reg1, reg2 to
lea (reg1,reg1,2), reg2
imul 3, reg1 to
lea (reg1,reg1,2), reg1}
TmpRef.base := Taicpu(p).oper[1].reg;
TmpRef.Index := Taicpu(p).oper[1].reg;
TmpRef.ScaleFactor := 2;
If (Taicpu(p).oper[2].typ = Top_None) Then
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg)
Else
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[2].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := hp1;
End;
5: Begin
{imul 5, reg1, reg2 to
lea (reg1,reg1,4), reg2
imul 5, reg1 to
lea (reg1,reg1,4), reg1}
TmpRef.base := Taicpu(p).oper[1].reg;
TmpRef.Index := Taicpu(p).oper[1].reg;
TmpRef.ScaleFactor := 4;
If (Taicpu(p).oper[2].typ = Top_None) Then
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg)
Else
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[2].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := hp1;
End;
6: Begin
{imul 6, reg1, reg2 to
lea (,reg1,2), reg2
lea (reg2,reg1,4), reg2
imul 6, reg1 to
lea (reg1,reg1,2), reg1
add reg1, reg1}
If (aktoptprocessor <= Class386)
Then
Begin
TmpRef.Index := Taicpu(p).oper[1].reg;
If (Taicpu(p).oper[2].typ = Top_Reg)
Then
Begin
TmpRef.base := Taicpu(p).oper[2].reg;
TmpRef.ScaleFactor := 4;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg);
End
Else
Begin
hp1 := Taicpu.op_reg_reg(A_ADD, S_L,
Taicpu(p).oper[1].reg,Taicpu(p).oper[1].reg);
End;
InsertLLItem(AsmL,p, p.next, hp1);
reference_reset_old(tmpref);
TmpRef.Index := Taicpu(p).oper[1].reg;
TmpRef.ScaleFactor := 2;
If (Taicpu(p).oper[2].typ = Top_Reg)
Then
Begin
TmpRef.base.enum := R_NO;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef,
Taicpu(p).oper[2].reg);
End
Else
Begin
TmpRef.base := Taicpu(p).oper[1].reg;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg);
End;
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := Tai(hp1.next);
End
End;
9: Begin
{imul 9, reg1, reg2 to
lea (reg1,reg1,8), reg2
imul 9, reg1 to
lea (reg1,reg1,8), reg1}
TmpRef.base := Taicpu(p).oper[1].reg;
TmpRef.Index := Taicpu(p).oper[1].reg;
TmpRef.ScaleFactor := 8;
If (Taicpu(p).oper[2].typ = Top_None) Then
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg)
Else
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[2].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := hp1;
End;
10: Begin
{imul 10, reg1, reg2 to
lea (reg1,reg1,4), reg2
add reg2, reg2
imul 10, reg1 to
lea (reg1,reg1,4), reg1
add reg1, reg1}
If (aktoptprocessor <= Class386) Then
Begin
If (Taicpu(p).oper[2].typ = Top_Reg) Then
hp1 := Taicpu.op_reg_reg(A_ADD, S_L,
Taicpu(p).oper[2].reg,Taicpu(p).oper[2].reg)
Else
hp1 := Taicpu.op_reg_reg(A_ADD, S_L,
Taicpu(p).oper[1].reg,Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p, p.next, hp1);
TmpRef.base := Taicpu(p).oper[1].reg;
TmpRef.Index := Taicpu(p).oper[1].reg;
TmpRef.ScaleFactor := 4;
If (Taicpu(p).oper[2].typ = Top_Reg)
Then
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[2].reg)
Else
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := Tai(hp1.next);
End
End;
12: Begin
{imul 12, reg1, reg2 to
lea (,reg1,4), reg2
lea (,reg1,8) reg2
imul 12, reg1 to
lea (reg1,reg1,2), reg1
lea (,reg1,4), reg1}
If (aktoptprocessor <= Class386)
Then
Begin
TmpRef.Index := Taicpu(p).oper[1].reg;
If (Taicpu(p).oper[2].typ = Top_Reg) Then
Begin
TmpRef.base := Taicpu(p).oper[2].reg;
TmpRef.ScaleFactor := 8;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[2].reg);
End
Else
Begin
TmpRef.base.enum := R_NO;
TmpRef.ScaleFactor := 4;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg);
End;
InsertLLItem(AsmL,p, p.next, hp1);
reference_reset_old(tmpref);
TmpRef.Index := Taicpu(p).oper[1].reg;
If (Taicpu(p).oper[2].typ = Top_Reg) Then
Begin
TmpRef.base.enum := R_NO;
TmpRef.ScaleFactor := 4;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[2].reg);
End
Else
Begin
TmpRef.base := Taicpu(p).oper[1].reg;
TmpRef.ScaleFactor := 2;
hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef, Taicpu(p).oper[1].reg);
End;
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := Tai(hp1.next);
End
End
End;
End;
End;
A_SAR, A_SHR:
{changes the code sequence
shr/sar const1, x
shl const2, x
to either "sar/and", "shl/and" or just "and" depending on const1 and const2}
Begin
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) and
(Taicpu(hp1).opcode = A_SHL) and
(Taicpu(p).oper[0].typ = top_const) and
(Taicpu(hp1).oper[0].typ = top_const) and
(Taicpu(hp1).opsize = Taicpu(p).opsize) And
(Taicpu(hp1).oper[1].typ = Taicpu(p).oper[1].typ) And
OpsEqual(Taicpu(hp1).oper[1], Taicpu(p).oper[1])
Then
If (Taicpu(p).oper[0].val > Taicpu(hp1).oper[0].val) And
Not(CS_LittleSize In aktglobalswitches)
Then
{ shr/sar const1, %reg
shl const2, %reg
with const1 > const2 }
Begin
Taicpu(p).LoadConst(0,Taicpu(p).oper[0].val-Taicpu(hp1).oper[0].val);
Taicpu(hp1).opcode := A_AND;
l := (1 shl (Taicpu(hp1).oper[0].val)) - 1;
Case Taicpu(p).opsize Of
S_L: Taicpu(hp1).LoadConst(0,l Xor aword($ffffffff));
S_B: Taicpu(hp1).LoadConst(0,l Xor $ff);
S_W: Taicpu(hp1).LoadConst(0,l Xor $ffff);
End;
End
Else
If (Taicpu(p).oper[0].val<Taicpu(hp1).oper[0].val) And
Not(CS_LittleSize In aktglobalswitches)
Then
{ shr/sar const1, %reg
shl const2, %reg
with const1 < const2 }
Begin
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val-Taicpu(p).oper[0].val);
Taicpu(p).opcode := A_AND;
l := (1 shl (Taicpu(p).oper[0].val))-1;
Case Taicpu(p).opsize Of
S_L: Taicpu(p).LoadConst(0,l Xor aword($ffffffff));
S_B: Taicpu(p).LoadConst(0,l Xor $ff);
S_W: Taicpu(p).LoadConst(0,l Xor $ffff);
End;
End
Else
{ shr/sar const1, %reg
shl const2, %reg
with const1 = const2 }
if (Taicpu(p).oper[0].val = Taicpu(hp1).oper[0].val) then
Begin
Taicpu(p).opcode := A_AND;
l := (1 shl (Taicpu(p).oper[0].val))-1;
Case Taicpu(p).opsize Of
S_B: Taicpu(p).LoadConst(0,l Xor $ff);
S_W: Taicpu(p).LoadConst(0,l Xor $ffff);
S_L: Taicpu(p).LoadConst(0,l Xor aword($ffffffff));
End;
asml.remove(hp1);
hp1.free;
End;
End;
A_XOR:
If (Taicpu(p).oper[0].typ = top_reg) And
(Taicpu(p).oper[1].typ = top_reg) And
(Taicpu(p).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum) then
{ temporarily change this to 'mov reg,0' to make it easier }
{ for the CSE. Will be changed back in pass 2 }
begin
Taicpu(p).opcode := A_MOV;
Taicpu(p).loadconst(0,0);
end;
End;
End;
End;
p := Tai(p.next)
End;
End;
Procedure PeepHoleOptPass1(Asml: TAAsmOutput; BlockStart, BlockEnd: Tai);
{First pass of peepholeoptimizations}
Var
l,l1 : longint;
p,hp1,hp2 : Tai;
hp3,hp4: Tai;
TmpRef: TReference;
UsedRegs, TmpUsedRegs: TRegSet;
TmpBool1, TmpBool2: Boolean;
r:Tregister;
Function SkipLabels(hp: Tai; var hp2: Tai): boolean;
{skips all labels and returns the next "real" instruction}
Begin
While assigned(hp.next) and
(Tai(hp.next).typ In SkipInstr + [ait_label,ait_align]) Do
hp := Tai(hp.next);
If assigned(hp.next) Then
Begin
SkipLabels := True;
hp2 := Tai(hp.next)
End
Else
Begin
hp2 := hp;
SkipLabels := False
End;
End;
function GetFinalDestination(AsmL: TAAsmOutput; hp: Taicpu; level: longint): boolean;
{traces sucessive jumps to their final destination and sets it, e.g.
je l1 je l3
<code> <code>
l1: becomes l1:
je l2 je l3
<code> <code>
l2: l2:
jmp l3 jmp l3
the level parameter denotes how deeep we have already followed the jump,
to avoid endless loops with constructs such as "l5: ; jmp l5" }
Var p1, p2: Tai;
l: tasmlabel;
Function FindAnyLabel(hp: Tai; var l: tasmlabel): Boolean;
Begin
FindAnyLabel := false;
While assigned(hp.next) and
(Tai(hp.next).typ In (SkipInstr+[ait_align])) Do
hp := Tai(hp.next);
If assigned(hp.next) and
(Tai(hp.next).typ = ait_label) Then
Begin
FindAnyLabel := true;
l := Tai_label(hp.next).l;
End
End;
Begin
if level > 20 then
exit;
GetfinalDestination := false;
p1 := dfa.getlabelwithsym(tasmlabel(hp.oper[0].sym));
if assigned(p1) then
begin
SkipLabels(p1,p1);
If (Tai(p1).typ = ait_instruction) and
(Taicpu(p1).is_jmp) Then
If { the next instruction after the label where the jump hp arrives}
{ is unconditional or of the same type as hp, so continue }
(Taicpu(p1).condition in [C_None,hp.condition]) or
{ the next instruction after the label where the jump hp arrives}
{ is the opposite of hp (so this one is never taken), but after }
{ that one there is a branch that will be taken, so perform a }
{ little hack: set p1 equal to this instruction (that's what the}
{ last SkipLabels is for, only works with short bool evaluation)}
((Taicpu(p1).condition = inverse_cond[hp.condition]) and
SkipLabels(p1,p2) and
(p2.typ = ait_instruction) and
(Taicpu(p2).is_jmp) and
(Taicpu(p2).condition in [C_None,hp.condition]) and
SkipLabels(p1,p1)) Then
Begin
{ quick check for loops of the form "l5: ; jmp l5 }
if (tasmlabel(Taicpu(p1).oper[0].sym).labelnr =
tasmlabel(hp.oper[0].sym).labelnr) then
exit;
if not GetFinalDestination(asml, Taicpu(p1),succ(level)) then
exit;
tasmlabel(hp.oper[0].sym).decrefs;
hp.oper[0].sym:=Taicpu(p1).oper[0].sym;
tasmlabel(hp.oper[0].sym).increfs;
End
Else
If (Taicpu(p1).condition = inverse_cond[hp.condition]) then
if not FindAnyLabel(p1,l) then
begin
{$ifdef finaldestdebug}
insertllitem(asml,p1,p1.next,tai_comment.Create(
strpnew('previous label inserted'))));
{$endif finaldestdebug}
objectlibrary.getlabel(l);
insertllitem(asml,p1,p1.next,Tai_label.Create(l));
tasmlabel(Taicpu(hp).oper[0].sym).decrefs;
hp.oper[0].sym := l;
l.increfs;
{ this won't work, since the new label isn't in the labeltable }
{ so it will fail the rangecheck. Labeltable should become a }
{ hashtable to support this: }
{ GetFinalDestination(asml, hp); }
end
else
begin
{$ifdef finaldestdebug}
insertllitem(asml,p1,p1.next,tai_comment.Create(
strpnew('next label reused'))));
{$endif finaldestdebug}
l.increfs;
hp.oper[0].sym := l;
if not GetFinalDestination(asml, hp,succ(level)) then
exit;
end;
End;
GetFinalDestination := true;
End;
Function DoSubAddOpt(var p: Tai): Boolean;
Begin
DoSubAddOpt := False;
If GetLastInstruction(p, hp1) And
(hp1.typ = ait_instruction) And
(Taicpu(hp1).opsize = Taicpu(p).opsize) then
Case Taicpu(hp1).opcode Of
A_DEC:
If (Taicpu(hp1).oper[0].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum) Then
Begin
Taicpu(p).LoadConst(0,Taicpu(p).oper[0].val+1);
asml.Remove(hp1);
hp1.free;
End;
A_SUB:
If (Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum) Then
Begin
Taicpu(p).LoadConst(0,Taicpu(p).oper[0].val+Taicpu(hp1).oper[0].val);
asml.Remove(hp1);
hp1.free;
End;
A_ADD:
If (Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum) Then
Begin
Taicpu(p).LoadConst(0,AWord(int64(Taicpu(p).oper[0].val)-int64(Taicpu(hp1).oper[0].val)));
asml.Remove(hp1);
hp1.free;
If (Taicpu(p).oper[0].val = 0) Then
Begin
hp1 := Tai(p.next);
asml.Remove(p);
p.free;
If Not GetLastInstruction(hp1, p) Then
p := hp1;
DoSubAddOpt := True;
End
End;
End;
End;
Begin
P := BlockStart;
UsedRegs := [];
While (P <> BlockEnd) Do
Begin
UpDateUsedRegs(UsedRegs, Tai(p.next));
Case p.Typ Of
ait_instruction:
Begin
{ Handle Jmp Optimizations }
if Taicpu(p).is_jmp then
begin
{the following if-block removes all code between a jmp and the next label,
because it can never be executed}
If (Taicpu(p).opcode = A_JMP) Then
Begin
While GetNextInstruction(p, hp1) and
(hp1.typ <> ait_label) do
If not(hp1.typ in ([ait_label,ait_align]+skipinstr)) Then
Begin
asml.Remove(hp1);
hp1.free;
End
else break;
End;
{ remove jumps to a label coming right after them }
If GetNextInstruction(p, hp1) then
Begin
if FindLabel(tasmlabel(Taicpu(p).oper[0].sym), hp1) and
{$warning FIXME removing the first instruction fails}
(p<>blockstart) then
Begin
hp2:=Tai(hp1.next);
asml.remove(p);
p.free;
p:=hp2;
continue;
end
Else
Begin
if hp1.typ = ait_label then
SkipLabels(hp1,hp1);
If (Tai(hp1).typ=ait_instruction) and
(Taicpu(hp1).opcode=A_JMP) and
GetNextInstruction(hp1, hp2) And
FindLabel(tasmlabel(Taicpu(p).oper[0].sym), hp2)
Then
Begin
if Taicpu(p).opcode=A_Jcc then
Taicpu(p).condition:=inverse_cond[Taicpu(p).condition]
else
begin
GetFinalDestination(asml, Taicpu(p),0);
p:=Tai(p.next);
continue;
end;
Tai_label(hp2).l.decrefs;
Taicpu(p).oper[0].sym:=Taicpu(hp1).oper[0].sym;
Taicpu(p).oper[0].sym.increfs;
asml.remove(hp1);
hp1.free;
GetFinalDestination(asml, Taicpu(p),0);
end
else
GetFinalDestination(asml, Taicpu(p),0);
end;
end;
end
else
{ All other optimizes }
begin
For l := 0 to 2 Do
If (Taicpu(p).oper[l].typ = top_ref) Then
With Taicpu(p).oper[l].ref^ Do
Begin
If (base.enum = R_NO) And
(index.enum <> R_NO) And
(scalefactor in [0,1])
Then
Begin
base := index;
index.enum := R_NO
End
End;
Case Taicpu(p).opcode Of
A_AND:
Begin
If (Taicpu(p).oper[0].typ = top_const) And
(Taicpu(p).oper[1].typ = top_reg) And
GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_AND) And
(Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(p).oper[1].reg.enum = Taicpu(hp1).oper[1].reg.enum)
Then
{change "and const1, reg; and const2, reg" to "and (const1 and const2), reg"}
Begin
Taicpu(p).LoadConst(0,Taicpu(p).oper[0].val And Taicpu(hp1).oper[0].val);
asml.Remove(hp1);
hp1.free;
End
Else
{change "and x, reg; jxx" to "test x, reg", if reg is deallocated before the
jump, but only if it's a conditional jump (PFV) }
If (Taicpu(p).oper[1].typ = top_reg) And
GetNextInstruction(p, hp1) And
(hp1.typ = ait_instruction) And
(Taicpu(hp1).is_jmp) and
(Taicpu(hp1).opcode<>A_JMP) and
Not(Taicpu(p).oper[1].reg.enum in UsedRegs) Then
Taicpu(p).opcode := A_TEST;
End;
A_CMP:
Begin
If (Taicpu(p).oper[0].typ = top_const) And
(Taicpu(p).oper[1].typ in [top_reg,top_ref]) And
(Taicpu(p).oper[0].val = 0) and
GetNextInstruction(p, hp1) And
(hp1.typ = ait_instruction) And
(Taicpu(hp1).is_jmp) and
(Taicpu(hp1).opcode=A_Jcc) and
(Taicpu(hp1).condition in [C_LE,C_BE]) and
GetNextInstruction(hp1,hp2) and
(hp2.typ = ait_instruction) and
(Taicpu(hp2).opcode = A_DEC) And
OpsEqual(Taicpu(hp2).oper[0],Taicpu(p).oper[1]) And
GetNextInstruction(hp2, hp3) And
(hp3.typ = ait_instruction) and
(Taicpu(hp3).is_jmp) and
(Taicpu(hp3).opcode = A_JMP) And
GetNextInstruction(hp3, hp4) And
FindLabel(tasmlabel(Taicpu(hp1).oper[0].sym),hp4) Then
Begin
Taicpu(hp2).Opcode := A_SUB;
Taicpu(hp2).Loadoper(1,Taicpu(hp2).oper[0]);
Taicpu(hp2).LoadConst(0,1);
Taicpu(hp2).ops:=2;
Taicpu(hp3).Opcode := A_Jcc;
Case Taicpu(hp1).condition of
C_LE: Taicpu(hp3).condition := C_GE;
C_BE: Taicpu(hp3).condition := C_AE;
End;
asml.Remove(p);
asml.Remove(hp1);
p.free;
hp1.free;
p := hp2;
continue;
End
End;
A_FLD:
Begin
If (Taicpu(p).oper[0].typ = top_reg) And
GetNextInstruction(p, hp1) And
(hp1.typ = Ait_Instruction) And
(Taicpu(hp1).oper[0].typ = top_reg) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum = R_ST) And
(Taicpu(hp1).oper[1].reg.enum = R_ST1) Then
{ change to
fld reg fxxx reg,st
fxxxp st, st1 (hp1)
Remark: non commutative operations must be reversed!
}
begin
Case Taicpu(hp1).opcode Of
A_FMULP,A_FADDP,
A_FSUBP,A_FDIVP,A_FSUBRP,A_FDIVRP:
begin
Case Taicpu(hp1).opcode Of
A_FADDP: Taicpu(hp1).opcode := A_FADD;
A_FMULP: Taicpu(hp1).opcode := A_FMUL;
A_FSUBP: Taicpu(hp1).opcode := A_FSUBR;
A_FSUBRP: Taicpu(hp1).opcode := A_FSUB;
A_FDIVP: Taicpu(hp1).opcode := A_FDIVR;
A_FDIVRP: Taicpu(hp1).opcode := A_FDIV;
End;
Taicpu(hp1).oper[0].reg := Taicpu(p).oper[0].reg;
Taicpu(hp1).oper[1].reg.enum := R_ST;
asml.Remove(p);
p.free;
p := hp1;
Continue;
end;
end;
end
else
If (Taicpu(p).oper[0].typ = top_ref) And
GetNextInstruction(p, hp2) And
(hp2.typ = Ait_Instruction) And
(Taicpu(hp2).oper[0].typ = top_reg) And
(Taicpu(hp2).oper[1].typ = top_reg) And
(Taicpu(p).opsize in [S_FS, S_FL]) And
(Taicpu(hp2).oper[0].reg.enum = R_ST) And
(Taicpu(hp2).oper[1].reg.enum = R_ST1) Then
If GetLastInstruction(p, hp1) And
(hp1.typ = Ait_Instruction) And
((Taicpu(hp1).opcode = A_FLD) Or
(Taicpu(hp1).opcode = A_FST)) And
(Taicpu(hp1).opsize = Taicpu(p).opsize) And
(Taicpu(hp1).oper[0].typ = top_ref) And
RefsEqual(Taicpu(p).oper[0].ref^, Taicpu(hp1).oper[0].ref^) Then
If ((Taicpu(hp2).opcode = A_FMULP) Or
(Taicpu(hp2).opcode = A_FADDP)) Then
{ change to
fld/fst mem1 (hp1) fld/fst mem1
fld mem1 (p) fadd/
faddp/ fmul st, st
fmulp st, st1 (hp2) }
Begin
asml.Remove(p);
p.free;
p := hp1;
If (Taicpu(hp2).opcode = A_FADDP) Then
Taicpu(hp2).opcode := A_FADD
Else
Taicpu(hp2).opcode := A_FMUL;
Taicpu(hp2).oper[1].reg.enum := R_ST;
End
Else
{ change to
fld/fst mem1 (hp1) fld/fst mem1
fld mem1 (p) fld st}
Begin
Taicpu(p).changeopsize(S_FL);
r.enum:=R_ST;
Taicpu(p).loadreg(0,r);
End
Else
Begin
Case Taicpu(hp2).opcode Of
A_FMULP,A_FADDP,A_FSUBP,A_FDIVP,A_FSUBRP,A_FDIVRP:
{ change to
fld/fst mem1 (hp1) fld/fst mem1
fld mem2 (p) fxxx mem2
fxxxp st, st1 (hp2) }
Begin
Case Taicpu(hp2).opcode Of
A_FADDP: Taicpu(p).opcode := A_FADD;
A_FMULP: Taicpu(p).opcode := A_FMUL;
A_FSUBP: Taicpu(p).opcode := A_FSUBR;
A_FSUBRP: Taicpu(p).opcode := A_FSUB;
A_FDIVP: Taicpu(p).opcode := A_FDIVR;
A_FDIVRP: Taicpu(p).opcode := A_FDIV;
End;
asml.Remove(hp2);
hp2.free;
End
End
End
End;
A_FSTP,A_FISTP:
if doFpuLoadStoreOpt(asmL,p) then
continue;
A_LEA:
Begin
{removes seg register prefixes from LEA operations, as they
don't do anything}
Taicpu(p).oper[0].ref^.Segment.enum := R_NO;
{changes "lea (%reg1), %reg2" into "mov %reg1, %reg2"}
If (Taicpu(p).oper[0].ref^.Base.enum In [R_EAX..R_EDI]) And
(Taicpu(p).oper[0].ref^.Index.enum = R_NO) And
(Not(Assigned(Taicpu(p).oper[0].ref^.Symbol))) Then
If (Taicpu(p).oper[0].ref^.Base.enum <> Taicpu(p).oper[1].reg.enum)
and (Taicpu(p).oper[0].ref^.Offset = 0)
Then
Begin
hp1 := Taicpu.op_reg_reg(A_MOV, S_L,Taicpu(p).oper[0].ref^.Base,
Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p.previous,p.next, hp1);
p.free;
p := hp1;
Continue;
End
Else
if (Taicpu(p).oper[0].ref^.Offset = 0) then
Begin
hp1 := Tai(p.Next);
asml.Remove(p);
p.free;
p := hp1;
Continue;
End
else
with Taicpu(p).oper[0].ref^ do
if (Base.enum = Taicpu(p).oper[1].reg.enum) then
begin
l := offset+offsetfixup;
if (l=1) then
begin
Taicpu(p).opcode := A_INC;
Taicpu(p).loadreg(0,Taicpu(p).oper[1].reg);
Taicpu(p).ops := 1
end
else
if (l=-1) then
begin
Taicpu(p).opcode := A_DEC;
Taicpu(p).loadreg(0,Taicpu(p).oper[1].reg);
Taicpu(p).ops := 1;
end
else
begin
Taicpu(p).opcode := A_ADD;
Taicpu(p).loadconst(0,aword(l));
end;
end;
End;
A_MOV:
Begin
TmpUsedRegs := UsedRegs;
If (Taicpu(p).oper[1].typ = top_reg) And
(Taicpu(p).oper[1].reg.enum In [R_EAX, R_EBX, R_ECX, R_EDX, R_ESI, R_EDI]) And
GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_MOV) And
(Taicpu(hp1).oper[0].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum)
Then
{we have "mov x, %treg; mov %treg, y}
If not(RegUsedAfterInstruction(Taicpu(p).oper[1].reg, hp1, TmpUsedRegs)) then
{we've got "mov x, %treg; mov %treg, y; with %treg is not used after }
Case Taicpu(p).oper[0].typ Of
top_reg:
Begin
{ change "mov %reg, %treg; mov %treg, y"
to "mov %reg, y" }
Taicpu(p).LoadOper(1,Taicpu(hp1).oper[1]);
asml.Remove(hp1);
hp1.free;
continue;
End;
top_ref:
If (Taicpu(hp1).oper[1].typ = top_reg) Then
Begin
{ change "mov mem, %treg; mov %treg, %reg"
to "mov mem, %reg" }
Taicpu(p).Loadoper(1,Taicpu(hp1).oper[1]);
asml.Remove(hp1);
hp1.free;
continue;
End;
End
Else
Else
{Change "mov %reg1, %reg2; xxx %reg2, ???" to
"mov %reg1, %reg2; xxx %reg1, ???" to avoid a write/read
penalty}
If (Taicpu(p).oper[0].typ = top_reg) And
(Taicpu(p).oper[1].typ = top_reg) And
GetNextInstruction(p,hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).oper[0].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum)
Then
{we have "mov %reg1, %reg2; XXX %reg2, ???"}
Begin
If ((Taicpu(hp1).opcode = A_OR) Or
(Taicpu(hp1).opcode = A_TEST)) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum = Taicpu(hp1).oper[1].reg.enum)
Then
{we have "mov %reg1, %reg2; test/or %reg2, %reg2"}
Begin
TmpUsedRegs := UsedRegs;
{ reg1 will be used after the first instruction, }
{ so update the allocation info }
allocRegBetween(asmL,Taicpu(p).oper[0].reg,p,hp1);
If GetNextInstruction(hp1, hp2) And
(hp2.typ = ait_instruction) And
Taicpu(hp2).is_jmp and
Not(RegUsedAfterInstruction(Taicpu(hp1).oper[0].reg, hp1, TmpUsedRegs))
Then
{change "mov %reg1, %reg2; test/or %reg2, %reg2; jxx" to
"test %reg1, %reg1; jxx"}
Begin
Taicpu(hp1).Loadoper(0,Taicpu(p).oper[0]);
Taicpu(hp1).Loadoper(1,Taicpu(p).oper[0]);
asml.Remove(p);
p.free;
p := hp1;
continue
End
Else
{change "mov %reg1, %reg2; test/or %reg2, %reg2" to
"mov %reg1, %reg2; test/or %reg1, %reg1"}
Begin
Taicpu(hp1).Loadoper(0,Taicpu(p).oper[0]);
Taicpu(hp1).Loadoper(1,Taicpu(p).oper[0]);
End;
End
{ Else
If (Taicpu(p.next)^.opcode
In [A_PUSH, A_OR, A_XOR, A_AND, A_TEST])}
{change "mov %reg1, %reg2; push/or/xor/... %reg2, ???" to
"mov %reg1, %reg2; push/or/xor/... %reg1, ???"}
End
Else
{leave out the mov from "mov reg, x(%frame_pointer); leave/ret" (with
x >= RetOffset) as it doesn't do anything (it writes either to a
parameter or to the temporary storage room for the function
result)}
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction)
Then
If ((Taicpu(hp1).opcode = A_LEAVE) Or
(Taicpu(hp1).opcode = A_RET)) And
(Taicpu(p).oper[1].typ = top_ref) And
(Taicpu(p).oper[1].ref^.base.enum = current_procinfo.FramePointer.enum) And
(Taicpu(p).oper[1].ref^.offset >= tvarsym(current_procinfo.procdef.funcretsym).adjusted_address) And
(Taicpu(p).oper[1].ref^.index.enum = R_NO) And
(Taicpu(p).oper[0].typ = top_reg)
Then
Begin
asml.Remove(p);
p.free;
p := hp1;
RemoveLastDeallocForFuncRes(asmL,p);
End
Else
If (Taicpu(p).oper[0].typ = top_reg) And
(Taicpu(p).oper[1].typ = top_ref) And
(Taicpu(p).opsize = Taicpu(hp1).opsize) And
(Taicpu(hp1).opcode = A_CMP) And
(Taicpu(hp1).oper[1].typ = top_ref) And
RefsEqual(Taicpu(p).oper[1].ref^, Taicpu(hp1).oper[1].ref^) Then
{change "mov reg1, mem1; cmp x, mem1" to "mov reg, mem1; cmp x, reg1"}
begin
Taicpu(hp1).loadreg(1,Taicpu(p).oper[0].reg);
allocRegBetween(asmL,Taicpu(p).oper[0].reg,p,hp1);
end;
{ Next instruction is also a MOV ? }
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) and
(Taicpu(hp1).opcode = A_MOV) and
(Taicpu(hp1).opsize = Taicpu(p).opsize)
Then
Begin
If (Taicpu(hp1).oper[0].typ = Taicpu(p).oper[1].typ) and
(Taicpu(hp1).oper[1].typ = Taicpu(p).oper[0].typ)
Then
{mov reg1, mem1 or mov mem1, reg1
mov mem2, reg2 mov reg2, mem2}
Begin
If OpsEqual(Taicpu(hp1).oper[1],Taicpu(p).oper[0]) Then
{mov reg1, mem1 or mov mem1, reg1
mov mem2, reg1 mov reg2, mem1}
Begin
If OpsEqual(Taicpu(hp1).oper[0],Taicpu(p).oper[1]) Then
{ Removes the second statement from
mov reg1, mem1/reg2
mov mem1/reg2, reg1 }
Begin
if (Taicpu(p).oper[0].typ = top_reg) then
AllocRegBetween(asmL,Taicpu(p).oper[0].reg,p,hp1);
asml.remove(hp1);
hp1.free;
End
Else
Begin
TmpUsedRegs := UsedRegs;
UpdateUsedRegs(TmpUsedRegs, Tai(hp1.next));
If (Taicpu(p).oper[1].typ = top_ref) And
{ mov reg1, mem1
mov mem2, reg1 }
GetNextInstruction(hp1, hp2) And
(hp2.typ = ait_instruction) And
(Taicpu(hp2).opcode = A_CMP) And
(Taicpu(hp2).opsize = Taicpu(p).opsize) and
(Taicpu(hp2).oper[0].typ = TOp_Ref) And
(Taicpu(hp2).oper[1].typ = TOp_Reg) And
RefsEqual(Taicpu(hp2).oper[0].ref^, Taicpu(p).oper[1].ref^) And
(Taicpu(hp2).oper[1].reg .enum= Taicpu(p).oper[0].reg.enum) And
Not(RegUsedAfterInstruction(Taicpu(p).oper[0].reg, hp2, TmpUsedRegs)) Then
{ change to
mov reg1, mem1 mov reg1, mem1
mov mem2, reg1 cmp reg1, mem2
cmp mem1, reg1 }
Begin
asml.Remove(hp2);
hp2.free;
Taicpu(hp1).opcode := A_CMP;
Taicpu(hp1).loadref(1,Taicpu(hp1).oper[0].ref^);
Taicpu(hp1).loadreg(0,Taicpu(p).oper[0].reg);
End;
End;
End
Else
Begin
tmpUsedRegs := UsedRegs;
r.enum:=R_EDI;
If GetNextInstruction(hp1, hp2) And
(Taicpu(p).oper[0].typ = top_ref) And
(Taicpu(p).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[0].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum) And
(Taicpu(hp1).oper[1].typ = top_ref) And
(Tai(hp2).typ = ait_instruction) And
(Taicpu(hp2).opcode = A_MOV) And
(Taicpu(hp2).opsize = Taicpu(p).opsize) and
(Taicpu(hp2).oper[1].typ = top_reg) And
(Taicpu(hp2).oper[0].typ = top_ref) And
RefsEqual(Taicpu(hp2).oper[0].ref^, Taicpu(hp1).oper[1].ref^) Then
If not regInRef(Taicpu(hp2).oper[1].reg,Taicpu(hp2).oper[0].ref^) and
(Taicpu(p).oper[1].reg.enum in [R_DI,R_EDI]) and
not(RegUsedAfterInstruction(r,hp1,tmpUsedRegs)) Then
{ mov mem1, %edi
mov %edi, mem2
mov mem2, reg2
to:
mov mem1, reg2
mov reg2, mem2}
Begin
AllocRegBetween(asmL,reg32(Taicpu(hp2).oper[1].reg),p,hp2);
Taicpu(p).Loadoper(1,Taicpu(hp2).oper[1]);
Taicpu(hp1).loadoper(0,Taicpu(hp2).oper[1]);
asml.Remove(hp2);
hp2.free;
End
Else
If (Taicpu(p).oper[1].reg.enum <> Taicpu(hp2).oper[1].reg.enum) And
not(RegInRef(Taicpu(p).oper[1].reg,Taicpu(p).oper[0].ref^)) And
not(RegInRef(Taicpu(hp2).oper[1].reg,Taicpu(hp2).oper[0].ref^))
Then
{ mov mem1, reg1 mov mem1, reg1
mov reg1, mem2 mov reg1, mem2
mov mem2, reg2 mov mem2, reg1
to: to:
mov mem1, reg1 mov mem1, reg1
mov mem1, reg2 mov reg1, mem2
mov reg1, mem2
or (if mem1 depends on reg1
and/or if mem2 depends on reg2)
to:
mov mem1, reg1
mov reg1, mem2
mov reg1, reg2
}
Begin
Taicpu(hp1).LoadRef(0,Taicpu(p).oper[0].ref^);
Taicpu(hp1).LoadReg(1,Taicpu(hp2).oper[1].reg);
Taicpu(hp2).LoadRef(1,Taicpu(hp2).oper[0].ref^);
Taicpu(hp2).LoadReg(0,Taicpu(p).oper[1].reg);
allocRegBetween(asmL,Taicpu(p).oper[1].reg,p,hp2);
{ if (Taicpu(p).oper[0].ref^.base.enum in (rg.usableregsint+[R_EDI])) then
allocRegBetween(asmL,Taicpu(p).oper[0].ref^.base,p,hp2);
if (Taicpu(p).oper[0].ref^.index.enum in (rg.usableregsint+[R_EDI])) then
allocRegBetween(asmL,Taicpu(p).oper[0].ref^.index,p,hp2);}
if (Taicpu(p).oper[0].ref^.base.enum in [R_EDI]) then
allocRegBetween(asmL,Taicpu(p).oper[0].ref^.base,p,hp2);
if (Taicpu(p).oper[0].ref^.index.enum in [R_EDI]) then
allocRegBetween(asmL,Taicpu(p).oper[0].ref^.index,p,hp2);
End
Else
If (Taicpu(hp1).Oper[0].reg.enum <> Taicpu(hp2).Oper[1].reg.enum) Then
begin
Taicpu(hp2).LoadReg(0,Taicpu(hp1).Oper[0].reg);
allocRegBetween(asmL,Taicpu(p).oper[1].reg,p,hp2);
end
else
begin
asml.Remove(hp2);
hp2.free;
end
End;
End
Else
(* {movl [mem1],reg1
movl [mem1],reg2
to:
movl [mem1],reg1
movl reg1,reg2 }
If (Taicpu(p).oper[0].typ = top_ref) and
(Taicpu(p).oper[1].typ = top_reg) and
(Taicpu(hp1).oper[0].typ = top_ref) and
(Taicpu(hp1).oper[1].typ = top_reg) and
(Taicpu(p).opsize = Taicpu(hp1).opsize) and
RefsEqual(TReference(Taicpu(p).oper[0]^),Taicpu(hp1).oper[0]^.ref^) and
(Taicpu(p).oper[1].reg<>Taicpu(hp1).oper[0]^.ref^.base) and
(Taicpu(p).oper[1].reg<>Taicpu(hp1).oper[0]^.ref^.index) then
Taicpu(hp1).LoadReg(0,Taicpu(p).oper[1].reg)
Else*)
{ movl const1,[mem1]
movl [mem1],reg1
to:
movl const1,reg1
movl reg1,[mem1] }
If (Taicpu(p).oper[0].typ = top_const) and
(Taicpu(p).oper[1].typ = top_ref) and
(Taicpu(hp1).oper[0].typ = top_ref) and
(Taicpu(hp1).oper[1].typ = top_reg) and
(Taicpu(p).opsize = Taicpu(hp1).opsize) and
RefsEqual(Taicpu(hp1).oper[0].ref^,Taicpu(p).oper[1].ref^) then
Begin
allocregbetween(asml,Taicpu(hp1).oper[1].reg,p,hp1);
{ allocregbetween doesn't insert this because at }
{ this time, no regalloc info is available in }
{ the optinfo field, so do it manually (JM) }
hp2 := tai_regalloc.Alloc(Taicpu(hp1).oper[1].reg);
insertllitem(asml,p.previous,p,hp2);
Taicpu(hp1).LoadReg(0,Taicpu(hp1).oper[1].reg);
Taicpu(hp1).LoadRef(1,Taicpu(p).oper[1].ref^);
Taicpu(p).LoadReg(1,Taicpu(hp1).oper[0].reg);
End
End;
End;
A_MOVZX:
Begin
{removes superfluous And's after movzx's}
If (Taicpu(p).oper[1].typ = top_reg) And
GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_AND) And
(Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum)
Then
Case Taicpu(p).opsize Of
S_BL, S_BW:
If (Taicpu(hp1).oper[0].val = $ff) Then
Begin
asml.Remove(hp1);
hp1.free;
End;
S_WL:
If (Taicpu(hp1).oper[0].val = $ffff) Then
Begin
asml.Remove(hp1);
hp1.free;
End;
End;
{changes some movzx constructs to faster synonims (all examples
are given with eax/ax, but are also valid for other registers)}
If (Taicpu(p).oper[1].typ = top_reg) Then
If (Taicpu(p).oper[0].typ = top_reg) Then
Case Taicpu(p).opsize of
S_BW:
Begin
If (changeregsize(Taicpu(p).oper[0].reg,S_W).enum=Taicpu(p).oper[1].reg.enum) And
Not(CS_LittleSize In aktglobalswitches)
Then
{Change "movzbw %al, %ax" to "andw $0x0ffh, %ax"}
Begin
Taicpu(p).opcode := A_AND;
Taicpu(p).changeopsize(S_W);
Taicpu(p).LoadConst(0,$ff);
End
Else
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_AND) And
(Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum)
Then
{Change "movzbw %reg1, %reg2; andw $const, %reg2"
to "movw %reg1, reg2; andw $(const1 and $ff), %reg2"}
Begin
Taicpu(p).opcode := A_MOV;
Taicpu(p).changeopsize(S_W);
Taicpu(p).LoadReg(0,changeregsize(Taicpu(p).oper[0].reg,S_W));
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val And $ff);
End;
End;
S_BL:
Begin
If (changeregsize(Taicpu(p).oper[0].reg,S_L).enum=Taicpu(p).oper[1].reg.enum) And
Not(CS_LittleSize in aktglobalswitches)
Then
{Change "movzbl %al, %eax" to "andl $0x0ffh, %eax"}
Begin
Taicpu(p).opcode := A_AND;
Taicpu(p).changeopsize(S_L);
Taicpu(p).loadconst(0,$ff)
End
Else
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_AND) And
(Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum)
Then
{Change "movzbl %reg1, %reg2; andl $const, %reg2"
to "movl %reg1, reg2; andl $(const1 and $ff), %reg2"}
Begin
Taicpu(p).opcode := A_MOV;
Taicpu(p).changeopsize(S_L);
Taicpu(p).LoadReg(0,changeregsize(Taicpu(p).oper[0].reg,S_L));
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val And $ff);
End
End;
S_WL:
Begin
If (changeregsize(Taicpu(p).oper[0].reg,S_L).enum=Taicpu(p).oper[1].reg.enum) And
Not(CS_LittleSize In aktglobalswitches)
Then
{Change "movzwl %ax, %eax" to "andl $0x0ffffh, %eax"}
Begin
Taicpu(p).opcode := A_AND;
Taicpu(p).changeopsize(S_L);
Taicpu(p).LoadConst(0,$ffff);
End
Else
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_AND) And
(Taicpu(hp1).oper[0].typ = top_const) And
(Taicpu(hp1).oper[1].typ = top_reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum)
Then
{Change "movzwl %reg1, %reg2; andl $const, %reg2"
to "movl %reg1, reg2; andl $(const1 and $ffff), %reg2"}
Begin
Taicpu(p).opcode := A_MOV;
Taicpu(p).changeopsize(S_L);
Taicpu(p).LoadReg(0,changeregsize(Taicpu(p).oper[0].reg,S_L));
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val And $ffff);
End;
End;
End
Else
If (Taicpu(p).oper[0].typ = top_ref) Then
Begin
If GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_AND) And
(Taicpu(hp1).oper[0].typ = Top_Const) And
(Taicpu(hp1).oper[1].typ = Top_Reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum) Then
Begin
Taicpu(p).opcode := A_MOV;
Case Taicpu(p).opsize Of
S_BL:
Begin
Taicpu(p).changeopsize(S_L);
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val And $ff);
End;
S_WL:
Begin
Taicpu(p).changeopsize(S_L);
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val And $ffff);
End;
S_BW:
Begin
Taicpu(p).changeopsize(S_W);
Taicpu(hp1).LoadConst(0,Taicpu(hp1).oper[0].val And $ff);
End;
End;
End;
End;
End;
A_POP:
Begin
if target_info.system=system_i386_go32v2 then
begin
{ Transform a series of pop/pop/pop/push/push/push to }
{ 'movl x(%esp),%reg' for go32v2 (not for the rest, }
{ because I'm not sure whether they can cope with }
{ 'movl x(%esp),%reg' with x > 0, I believe we had }
{ such a problem when using esp as frame pointer (JM) }
if (Taicpu(p).oper[0].typ = top_reg) then
begin
hp1 := p;
hp2 := p;
l := 0;
while getNextInstruction(hp1,hp1) and
(hp1.typ = ait_instruction) and
(Taicpu(hp1).opcode = A_POP) and
(Taicpu(hp1).oper[0].typ = top_reg) do
begin
hp2 := hp1;
inc(l,4);
end;
getLastInstruction(p,hp3);
l1 := 0;
while (hp2 <> hp3) and
assigned(hp1) and
(hp1.typ = ait_instruction) and
(Taicpu(hp1).opcode = A_PUSH) and
(Taicpu(hp1).oper[0].typ = top_reg) and
(Taicpu(hp1).oper[0].reg.enum = Taicpu(hp2).oper[0].reg.enum) do
begin
{ change it to a two op operation }
Taicpu(hp2).oper[1].typ:=top_none;
Taicpu(hp2).ops:=2;
Taicpu(hp2).opcode := A_MOV;
Taicpu(hp2).Loadoper(1,Taicpu(hp1).oper[0]);
reference_reset_old(tmpref);
tmpRef.base.enum:=R_INTREGISTER;
tmpRef.base.number:=NR_STACK_POINTER_REG;
convert_register_to_enum(tmpref.base);
tmpRef.offset := l;
Taicpu(hp2).loadRef(0,tmpRef);
hp4 := hp1;
getNextInstruction(hp1,hp1);
asml.remove(hp4);
hp4.free;
getLastInstruction(hp2,hp2);
dec(l,4);
inc(l1);
end;
if l <> -4 then
begin
inc(l,4);
for l1 := l1 downto 1 do
begin
getNextInstruction(hp2,hp2);
dec(Taicpu(hp2).oper[0].ref^.offset,l);
end
end
end
end
else
begin
if (Taicpu(p).oper[0].typ = top_reg) And
GetNextInstruction(p, hp1) And
(Tai(hp1).typ=ait_instruction) and
(Taicpu(hp1).opcode=A_PUSH) and
(Taicpu(hp1).oper[0].typ = top_reg) And
(Taicpu(hp1).oper[0].reg.enum=Taicpu(p).oper[0].reg.enum) then
Begin
{ change it to a two op operation }
Taicpu(p).oper[1].typ:=top_none;
Taicpu(p).ops:=2;
Taicpu(p).opcode := A_MOV;
Taicpu(p).Loadoper(1,Taicpu(p).oper[0]);
reference_reset_old(tmpref);
TmpRef.base.enum := R_ESP;
Taicpu(p).LoadRef(0,TmpRef);
asml.Remove(hp1);
hp1.free;
End;
end;
end;
A_PUSH:
Begin
If (Taicpu(p).opsize = S_W) And
(Taicpu(p).oper[0].typ = Top_Const) And
GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_PUSH) And
(Taicpu(hp1).oper[0].typ = Top_Const) And
(Taicpu(hp1).opsize = S_W) Then
Begin
Taicpu(p).changeopsize(S_L);
Taicpu(p).LoadConst(0,Taicpu(p).oper[0].val shl 16 + word(Taicpu(hp1).oper[0].val));
asml.Remove(hp1);
hp1.free;
End;
End;
A_SHL, A_SAL:
Begin
If (Taicpu(p).oper[0].typ = Top_Const) And
(Taicpu(p).oper[1].typ = Top_Reg) And
(Taicpu(p).opsize = S_L) And
(Taicpu(p).oper[0].val <= 3)
{Changes "shl const, %reg32; add const/reg, %reg32" to one lea statement}
Then
Begin
TmpBool1 := True; {should we check the next instruction?}
TmpBool2 := False; {have we found an add/sub which could be
integrated in the lea?}
reference_reset_old(tmpref);
TmpRef.index := Taicpu(p).oper[1].reg;
TmpRef.scalefactor := 1 shl Taicpu(p).oper[0].val;
While TmpBool1 And
GetNextInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) And
((((Taicpu(hp1).opcode = A_ADD) Or
(Taicpu(hp1).opcode = A_SUB)) And
(Taicpu(hp1).oper[1].typ = Top_Reg) And
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum)) or
(((Taicpu(hp1).opcode = A_INC) or
(Taicpu(hp1).opcode = A_DEC)) and
(Taicpu(hp1).oper[0].typ = Top_Reg) and
(Taicpu(hp1).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum))) Do
Begin
TmpBool1 := False;
If (Taicpu(hp1).oper[0].typ = Top_Const)
Then
Begin
TmpBool1 := True;
TmpBool2 := True;
case Taicpu(hp1).opcode of
A_ADD:
inc(TmpRef.offset, longint(Taicpu(hp1).oper[0].val));
A_SUB:
dec(TmpRef.offset, longint(Taicpu(hp1).oper[0].val));
end;
asml.Remove(hp1);
hp1.free;
End
Else
If (Taicpu(hp1).oper[0].typ = Top_Reg) And
(((Taicpu(hp1).opcode = A_ADD) And
(TmpRef.base.enum = R_NO)) or
(Taicpu(hp1).opcode = A_INC) or
(Taicpu(hp1).opcode = A_DEC)) Then
Begin
TmpBool1 := True;
TmpBool2 := True;
case Taicpu(hp1).opcode of
A_ADD:
TmpRef.base := Taicpu(hp1).oper[0].reg;
A_INC:
inc(TmpRef.offset);
A_DEC:
dec(TmpRef.offset);
end;
asml.Remove(hp1);
hp1.free;
End;
End;
If TmpBool2 Or
((aktoptprocessor < ClassP6) And
(Taicpu(p).oper[0].val <= 3) And
Not(CS_LittleSize in aktglobalswitches))
Then
Begin
If Not(TmpBool2) And
(Taicpu(p).oper[0].val = 1)
Then
Begin
hp1 := Taicpu.Op_reg_reg(A_ADD,Taicpu(p).opsize,
Taicpu(p).oper[1].reg, Taicpu(p).oper[1].reg)
End
Else hp1 := Taicpu.op_ref_reg(A_LEA, S_L, TmpRef,
Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := hp1;
End;
End
Else
If (aktoptprocessor < ClassP6) And
(Taicpu(p).oper[0].typ = top_const) And
(Taicpu(p).oper[1].typ = top_reg) Then
If (Taicpu(p).oper[0].val = 1)
Then
{changes "shl $1, %reg" to "add %reg, %reg", which is the same on a 386,
but faster on a 486, and Tairable in both U and V pipes on the Pentium
(unlike shl, which is only Tairable in the U pipe)}
Begin
hp1 := Taicpu.Op_reg_reg(A_ADD,Taicpu(p).opsize,
Taicpu(p).oper[1].reg, Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := hp1;
End
Else If (Taicpu(p).opsize = S_L) and
(Taicpu(p).oper[0].val<= 3) Then
{changes "shl $2, %reg" to "lea (,%reg,4), %reg"
"shl $3, %reg" to "lea (,%reg,8), %reg}
Begin
reference_reset_old(tmpref);
TmpRef.index := Taicpu(p).oper[1].reg;
TmpRef.scalefactor := 1 shl Taicpu(p).oper[0].val;
hp1 := Taicpu.Op_ref_reg(A_LEA,S_L,TmpRef, Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p.previous, p.next, hp1);
p.free;
p := hp1;
End
End;
A_SETcc :
{ changes
setcc (funcres) setcc reg
movb (funcres), reg to leave/ret
leave/ret }
Begin
If (Taicpu(p).oper[0].typ = top_ref) And
GetNextInstruction(p, hp1) And
GetNextInstruction(hp1, hp2) And
(hp2.typ = ait_instruction) And
((Taicpu(hp2).opcode = A_LEAVE) or
(Taicpu(hp2).opcode = A_RET)) And
(Taicpu(p).oper[0].ref^.Base.enum = current_procinfo.FramePointer.enum) And
(Taicpu(p).oper[0].ref^.Index.enum = R_NO) And
(Taicpu(p).oper[0].ref^.Offset >= tvarsym(current_procinfo.procdef.funcretsym).adjusted_address) And
(hp1.typ = ait_instruction) And
(Taicpu(hp1).opcode = A_MOV) And
(Taicpu(hp1).opsize = S_B) And
(Taicpu(hp1).oper[0].typ = top_ref) And
RefsEqual(Taicpu(hp1).oper[0].ref^, Taicpu(p).oper[0].ref^) Then
Begin
Taicpu(p).LoadReg(0,Taicpu(hp1).oper[1].reg);
asml.Remove(hp1);
hp1.free;
End
End;
A_SUB:
{ * change "subl $2, %esp; pushw x" to "pushl x"}
{ * change "sub/add const1, reg" or "dec reg" followed by
"sub const2, reg" to one "sub ..., reg" }
Begin
If (Taicpu(p).oper[0].typ = top_const) And
(Taicpu(p).oper[1].typ = top_reg) Then
If (Taicpu(p).oper[0].val = 2) And
(Taicpu(p).oper[1].reg.enum = R_ESP) and
{ Don't do the sub/push optimization if the sub }
{ comes from setting up the stack frame (JM) }
(not getLastInstruction(p,hp1) or
(hp1.typ <> ait_instruction) or
(Taicpu(hp1).opcode <> A_MOV) or
(Taicpu(hp1).oper[0].typ <> top_reg) or
(Taicpu(hp1).oper[0].reg.enum <> R_ESP) or
(Taicpu(hp1).oper[1].typ <> top_reg) or
(Taicpu(hp1).oper[1].reg.enum <> R_EBP)) then
Begin
hp1 := Tai(p.next);
r.enum:=R_ESP;
While Assigned(hp1) And
(Tai(hp1).typ In [ait_instruction]+SkipInstr) And
not regReadByInstruction(r,hp1) and
not regModifiedByInstruction(r,hp1) do
hp1 := Tai(hp1.next);
If Assigned(hp1) And
(Tai(hp1).typ = ait_instruction) And
(Taicpu(hp1).opcode = A_PUSH) And
(Taicpu(hp1).opsize = S_W)
Then
Begin
Taicpu(hp1).changeopsize(S_L);
if Taicpu(hp1).oper[0].typ=top_reg then
Taicpu(hp1).LoadReg(0,changeregsize(Taicpu(hp1).oper[0].reg,S_L));
hp1 := Tai(p.next);
asml.Remove(p);
p.free;
p := hp1;
Continue
End;
If DoSubAddOpt(p) Then continue;
End
Else If DoSubAddOpt(p) Then Continue
End;
A_XOR:
If (Taicpu(p).oper[0].typ = top_reg) And
(Taicpu(p).oper[1].typ = top_reg) And
(Taicpu(p).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum) then
{ temporarily change this to 'mov reg,0' to make it easier }
{ for the CSE. Will be changed back in pass 2 }
begin
Taicpu(p).opcode := A_MOV;
Taicpu(p).loadconst(0,0);
end;
End;
end; { if is_jmp }
End;
{ ait_label:
Begin
If labelCanBeSkipped(Tai_label(p))
Then
Begin
hp1 := Tai(p.next);
asml.Remove(p);
p.free;
p := hp1;
Continue
End;
End;}
End;
updateUsedRegs(UsedRegs,p);
p:=Tai(p.next);
end;
end;
function isFoldableArithOp(hp1: Taicpu; reg: Toldregister): boolean;
begin
IsFoldableArithOp := False;
case hp1.opcode of
A_ADD,A_SUB,A_OR,A_XOR,A_AND,A_SHL,A_SHR,A_SAR:
isFoldableArithOp :=
((Taicpu(hp1).oper[0].typ = top_const) or
((Taicpu(hp1).oper[0].typ = top_reg) and
(Taicpu(hp1).oper[0].reg.enum <> reg))) and
(Taicpu(hp1).oper[1].typ = top_reg) and
(Taicpu(hp1).oper[1].reg.enum = reg);
A_INC,A_DEC:
isFoldableArithOp :=
(Taicpu(hp1).oper[0].typ = top_reg) and
(Taicpu(hp1).oper[0].reg.enum = reg);
end;
end;
Procedure PeepHoleOptPass2(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
{$ifdef USECMOV}
function CanBeCMOV(p : Tai) : boolean;
begin
CanBeCMOV:=assigned(p) and (p.typ=ait_instruction) and
(Taicpu(p).opcode=A_MOV) and
(Taicpu(p).opsize in [S_L,S_W]) and
(Taicpu(p).oper[0].typ in [top_reg,top_ref]) and
(Taicpu(p).oper[1].typ in [top_reg]);
end;
{$endif USECMOV}
var
p,hp1,hp2: Tai;
{$ifdef USECMOV}
l : longint;
condition : tasmcond;
hp3: Tai;
{$endif USECMOV}
UsedRegs, TmpUsedRegs: TRegSet;
Begin
P := BlockStart;
UsedRegs := [];
While (P <> BlockEnd) Do
Begin
UpdateUsedRegs(UsedRegs, Tai(p.next));
Case p.Typ Of
Ait_Instruction:
Begin
Case Taicpu(p).opcode Of
{$ifdef USECMOV}
A_Jcc:
if (aktspecificoptprocessor=ClassP6) then
begin
{ check for
jCC xxx
<several movs>
xxx:
}
l:=0;
GetNextInstruction(p, hp1);
while assigned(hp1) And
CanBeCMOV(hp1) do
begin
inc(l);
GetNextInstruction(hp1,hp1);
end;
if assigned(hp1) then
begin
if FindLabel(tasmlabel(Taicpu(p).oper[0].sym),hp1) then
begin
if (l<=4) and (l>0) then
begin
condition:=inverse_cond[Taicpu(p).condition];
GetNextInstruction(p,hp1);
asml.remove(p);
p.free;
p:=hp1;
repeat
Taicpu(hp1).opcode:=A_CMOVcc;
Taicpu(hp1).condition:=condition;
GetNextInstruction(hp1,hp1);
until not(assigned(hp1)) or
not(CanBeCMOV(hp1));
asml.remove(hp1);
hp1.free;
continue;
end;
end
else
begin
{ check further for
jCC xxx
<several movs>
jmp yyy
xxx:
<several movs>
yyy:
}
{ hp2 points to jmp xxx }
hp2:=hp1;
{ skip hp1 to xxx }
GetNextInstruction(hp1, hp1);
if assigned(hp2) and
assigned(hp1) and
(l<=3) and
(hp2.typ=ait_instruction) and
(Taicpu(hp2).is_jmp) and
(Taicpu(hp2).condition=C_None) and
FindLabel(tasmlabel(Taicpu(p).oper[0].sym),hp1) then
begin
l:=0;
while assigned(hp1) And
CanBeCMOV(hp1) do
begin
inc(l);
GetNextInstruction(hp1, hp1);
end;
end;
{
if assigned(hp1) and
FindLabel(tasmlabel(Taicpu(hp2).oper[0].sym),hp1) then
begin
condition:=inverse_cond[Taicpu(p).condition];
GetNextInstruction(p,hp1);
asml.remove(p);
p.free;
p:=hp1;
repeat
Taicpu(hp1).opcode:=A_CMOVcc;
Taicpu(hp1).condition:=condition;
GetNextInstruction(hp1,hp1);
until not(assigned(hp1)) or
not(CanBeCMOV(hp1));
hp2:=hp1.next;
condition:=inverse_cond[condition];
asml.remove(hp1.next)
hp1.next.free;
asml.remove(hp1);
hp1.free;
continue;
end;
}
end;
end;
end;
{$endif USECMOV}
A_FSTP,A_FISTP:
if doFpuLoadStoreOpt(asmL,p) then
continue;
A_IMUL:
begin
if ((Taicpu(p).oper[0].typ = top_const) or
(Taicpu(p).oper[0].typ = top_symbol)) and
(Taicpu(p).oper[1].typ = top_reg) and
((Taicpu(p).oper[2].typ = top_none) or
((Taicpu(p).oper[2].typ = top_reg) and
(Taicpu(p).oper[2].reg.enum = Taicpu(p).oper[1].reg.enum))) and
getLastInstruction(p,hp1) and
(hp1.typ = ait_instruction) and
(Taicpu(hp1).opcode = A_MOV) and
(Taicpu(hp1).oper[0].typ = top_reg) and
(Taicpu(hp1).oper[1].typ = top_reg) and
(Taicpu(hp1).oper[1].reg.enum = Taicpu(p).oper[1].reg.enum) then
{ change "mov reg1,reg2; imul y,reg2" to "imul y,reg1,reg2" }
begin
Taicpu(p).ops := 3;
Taicpu(p).loadreg(1,Taicpu(hp1).oper[0].reg);
Taicpu(p).loadreg(2,Taicpu(hp1).oper[1].reg);
asml.remove(hp1);
hp1.free;
end;
end;
A_MOV:
Begin
If (Taicpu(p).oper[0].typ = top_reg) And
(Taicpu(p).oper[1].typ = top_reg) And
GetNextInstruction(p, hp1) And
(hp1.typ = ait_Instruction) And
((Taicpu(hp1).opcode = A_MOV) or
(Taicpu(hp1).opcode = A_MOVZX) or
(Taicpu(hp1).opcode = A_MOVSX)) And
(Taicpu(hp1).oper[0].typ = top_ref) And
(Taicpu(hp1).oper[1].typ = top_reg) And
((Taicpu(hp1).oper[0].ref^.Base.enum = Taicpu(p).oper[1].reg.enum) Or
(Taicpu(hp1).oper[0].ref^.Index.enum = Taicpu(p).oper[1].reg.enum)) And
(Reg32(Taicpu(hp1).oper[1].reg).enum = Taicpu(p).oper[1].reg.enum) Then
{mov reg1, reg2
mov/zx/sx (reg2, ..), reg2 to mov/zx/sx (reg1, ..), reg2}
Begin
If (Taicpu(hp1).oper[0].ref^.Base.enum = Taicpu(p).oper[1].reg.enum) Then
Taicpu(hp1).oper[0].ref^.Base.enum := Taicpu(p).oper[0].reg.enum;
If (Taicpu(hp1).oper[0].ref^.Index.enum = Taicpu(p).oper[1].reg.enum) Then
Taicpu(hp1).oper[0].ref^.Index.enum := Taicpu(p).oper[0].reg.enum;
asml.Remove(p);
p.free;
p := hp1;
Continue;
End
Else If (Taicpu(p).oper[0].typ = top_ref) And
GetNextInstruction(p,hp1) And
(hp1.typ = ait_instruction) And
IsFoldableArithOp(Taicpu(hp1),Taicpu(p).oper[1].reg.enum) And
GetNextInstruction(hp1,hp2) And
(hp2.typ = ait_instruction) And
(Taicpu(hp2).opcode = A_MOV) And
(Taicpu(hp2).oper[0].typ = top_reg) And
(Taicpu(hp2).oper[0].reg.enum = Taicpu(p).oper[1].reg.enum) And
(Taicpu(hp2).oper[1].typ = top_ref) Then
Begin
TmpUsedRegs := UsedRegs;
UpdateUsedRegs(TmpUsedRegs,Tai(hp1.next));
If (RefsEqual(Taicpu(hp2).oper[1].ref^, Taicpu(p).oper[0].ref^) And
Not(RegUsedAfterInstruction(Taicpu(p).oper[1].reg,
hp2, TmpUsedRegs)))
Then
{ change mov (ref), reg }
{ add/sub/or/... reg2/$const, reg }
{ mov reg, (ref) }
{ # release reg }
{ to add/sub/or/... reg2/$const, (ref) }
Begin
case Taicpu(hp1).opcode of
A_INC,A_DEC:
Taicpu(hp1).LoadRef(0,Taicpu(p).oper[0].ref^)
else
Taicpu(hp1).LoadRef(1,Taicpu(p).oper[0].ref^);
end;
asml.Remove(p);
asml.Remove(hp2);
p.free;
hp2.free;
p := hp1
End;
End
End;
End;
End;
End;
p := Tai(p.next)
End;
End;
Procedure PostPeepHoleOpts(AsmL: TAAsmOutput; BlockStart, BlockEnd: Tai);
var
p,hp1,hp2: Tai;
Begin
P := BlockStart;
While (P <> BlockEnd) Do
Begin
Case p.Typ Of
Ait_Instruction:
Begin
Case Taicpu(p).opcode Of
A_CALL:
If (AktOptProcessor < ClassP6) And
GetNextInstruction(p, hp1) And
(hp1.typ = ait_instruction) And
(Taicpu(hp1).opcode = A_JMP) And
(Taicpu(hp1).oper[0].typ = top_symbol) Then
Begin
hp2 := Taicpu.Op_sym(A_PUSH,S_L,Taicpu(hp1).oper[0].sym);
InsertLLItem(AsmL, p.previous, p, hp2);
Taicpu(p).opcode := A_JMP;
Taicpu(p).is_jmp := true;
asml.Remove(hp1);
hp1.free;
End;
A_CMP:
Begin
if (Taicpu(p).oper[0].typ = top_const) and
(Taicpu(p).oper[0].val = 0) and
(Taicpu(p).oper[1].typ = top_reg) then
{change "cmp $0, %reg" to "test %reg, %reg"}
begin
Taicpu(p).opcode := A_TEST;
Taicpu(p).loadreg(0,Taicpu(p).oper[1].reg);
continue;
end;
End;
(*
Optimization is not safe; xor clears the carry flag.
See test/tgadint64 in the test suite.
A_MOV:
if (Taicpu(p).oper[0].typ = Top_Const) And
(Taicpu(p).oper[0].val = 0) And
(Taicpu(p).oper[1].typ = Top_Reg) Then
{ change "mov $0, %reg" into "xor %reg, %reg" }
Begin
Taicpu(p).opcode := A_XOR;
Taicpu(p).LoadReg(0,Taicpu(p).oper[1].reg);
End;
*)
A_MOVZX:
{ if register vars are on, it's possible there is code like }
{ "cmpl $3,%eax; movzbl 8(%ebp),%ebx; je .Lxxx" }
{ so we can't safely replace the movzx then with xor/mov, }
{ since that would change the flags (JM) }
if not(cs_regvars in aktglobalswitches) then
Begin
If (Taicpu(p).oper[1].typ = top_reg) Then
If (Taicpu(p).oper[0].typ = top_reg)
Then
Case Taicpu(p).opsize of
S_BL:
Begin
If IsGP32Reg(Taicpu(p).oper[1].reg) And
Not(CS_LittleSize in aktglobalswitches) And
(aktoptprocessor = ClassP5)
Then
{Change "movzbl %reg1, %reg2" to
"xorl %reg2, %reg2; movb %reg1, %reg2" for Pentium and
PentiumMMX}
Begin
hp1 := Taicpu.op_reg_reg(A_XOR, S_L,
Taicpu(p).oper[1].reg, Taicpu(p).oper[1].reg);
InsertLLItem(AsmL,p.previous, p, hp1);
Taicpu(p).opcode := A_MOV;
Taicpu(p).changeopsize(S_B);
Taicpu(p).LoadReg(1,changeregsize(Taicpu(p).oper[1].reg,S_B));
End;
End;
End
Else
If (Taicpu(p).oper[0].typ = top_ref) And
(Taicpu(p).oper[0].ref^.base.enum <> Taicpu(p).oper[1].reg.enum) And
(Taicpu(p).oper[0].ref^.index.enum <> Taicpu(p).oper[1].reg.enum) And
Not(CS_LittleSize in aktglobalswitches) And
IsGP32Reg(Taicpu(p).oper[1].reg) And
(aktoptprocessor = ClassP5) And
(Taicpu(p).opsize = S_BL)
Then
{changes "movzbl mem, %reg" to "xorl %reg, %reg; movb mem, %reg8" for
Pentium and PentiumMMX}
Begin
hp1 := Taicpu.Op_reg_reg(A_XOR, S_L, Taicpu(p).oper[1].reg,
Taicpu(p).oper[1].reg);
Taicpu(p).opcode := A_MOV;
Taicpu(p).changeopsize(S_B);
Taicpu(p).LoadReg(1,changeregsize(Taicpu(p).oper[1].reg,S_B));
InsertLLItem(AsmL,p.previous, p, hp1);
End;
End;
A_TEST, A_OR:
{removes the line marked with (x) from the sequence
And/or/xor/add/sub/... $x, %y
test/or %y, %y (x)
j(n)z _Label
as the first instruction already adjusts the ZF}
Begin
If OpsEqual(Taicpu(p).oper[0],Taicpu(p).oper[1]) Then
If GetLastInstruction(p, hp1) And
(Tai(hp1).typ = ait_instruction) Then
Case Taicpu(hp1).opcode Of
A_ADD, A_SUB, A_OR, A_XOR, A_AND{, A_SHL, A_SHR}:
Begin
If OpsEqual(Taicpu(hp1).oper[1],Taicpu(p).oper[0]) Then
Begin
hp1 := Tai(p.next);
asml.remove(p);
p.free;
p := Tai(hp1);
continue
End;
End;
A_DEC, A_INC, A_NEG:
Begin
If OpsEqual(Taicpu(hp1).oper[0],Taicpu(p).oper[0]) Then
Begin
Case Taicpu(hp1).opcode Of
A_DEC, A_INC:
{replace inc/dec with add/sub 1, because inc/dec doesn't set the carry flag}
Begin
Case Taicpu(hp1).opcode Of
A_DEC: Taicpu(hp1).opcode := A_SUB;
A_INC: Taicpu(hp1).opcode := A_ADD;
End;
Taicpu(hp1).Loadoper(1,Taicpu(hp1).oper[0]);
Taicpu(hp1).LoadConst(0,1);
Taicpu(hp1).ops:=2;
End
End;
hp1 := Tai(p.next);
asml.remove(p);
p.free;
p := Tai(hp1);
continue
End;
End
End
End;
End;
End;
End;
p := Tai(p.next)
End;
End;
End.
{
$Log$
Revision 1.48 2003-08-09 18:56:54 daniel
* cs_regalloc renamed to cs_regvars to avoid confusion with register
allocator
* Some preventive changes to i386 spillinh code
Revision 1.47 2003/06/08 18:48:03 jonas
* first small steps towards an oop optimizer
Revision 1.46 2003/06/03 21:09:05 peter
* internal changeregsize for optimizer
* fix with a hack to not remove the first instruction of a block
which will leave blockstart pointing to invalid memory
Revision 1.45 2003/06/02 21:42:05 jonas
* function results can now also be regvars
- removed tprocinfo.return_offset, never use it again since it's invalid
if the result is a regvar
Revision 1.44 2003/05/30 23:57:08 peter
* more sparc cleanup
* accumulator removed, splitted in function_return_reg (called) and
function_result_reg (caller)
Revision 1.43 2003/04/27 11:21:35 peter
* aktprocdef renamed to current_procdef
* procinfo renamed to current_procinfo
* procinfo will now be stored in current_module so it can be
cleaned up properly
* gen_main_procsym changed to create_main_proc and release_main_proc
to also generate a tprocinfo structure
* fixed unit implicit initfinal
Revision 1.42 2003/03/28 19:16:57 peter
* generic constructor working for i386
* remove fixed self register
* esi added as address register for i386
Revision 1.41 2003/02/26 13:24:59 daniel
* Disabled mov reg,0 -> xor reg,reg optimization
Revision 1.40 2003/02/25 07:41:54 daniel
* Properly fixed reversed operands bug
Revision 1.39 2003/02/24 21:27:01 daniel
* Reversed operand order in an optimization in postpeepholeopt
Revision 1.38 2003/02/19 22:39:56 daniel
* Fixed a few issues
Revision 1.37 2003/02/19 22:00:16 daniel
* Code generator converted to new register notation
- Horribily outdated todo.txt removed
Revision 1.36 2003/01/08 18:43:57 daniel
* Tregister changed into a record
Revision 1.35 2002/11/15 16:30:54 peter
* made tasmsymbol.refs private (merged)
Revision 1.34 2002/08/18 20:06:30 peter
* inlining is now also allowed in interface
* renamed write/load to ppuwrite/ppuload
* tnode storing in ppu
* nld,ncon,nbas are already updated for storing in ppu
Revision 1.33 2002/08/17 09:23:46 florian
* first part of procinfo rewrite
Revision 1.32 2002/08/11 14:32:30 peter
* renamed current_library to objectlibrary
Revision 1.31 2002/08/11 13:24:17 peter
* saving of asmsymbols in ppu supported
* asmsymbollist global is removed and moved into a new class
tasmlibrarydata that will hold the info of a .a file which
corresponds with a single module. Added librarydata to tmodule
to keep the library info stored for the module. In the future the
objectfiles will also be stored to the tasmlibrarydata class
* all getlabel/newasmsymbol and friends are moved to the new class
Revision 1.30 2002/07/26 21:15:43 florian
* rewrote the system handling
Revision 1.29 2002/07/01 18:46:34 peter
* internal linker
* reorganized aasm layer
Revision 1.28 2002/06/09 12:55:23 jonas
* fixed detection of register usage
Revision 1.27 2002/05/18 13:34:25 peter
* readded missing revisions
Revision 1.26 2002/05/16 19:46:52 carl
+ defines.inc -> fpcdefs.inc to avoid conflicts if compiling by hand
+ try to fix temp allocation (still in ifdef)
+ generic constructor calls
+ start of tassembler / tmodulebase class cleanup
Revision 1.24 2002/05/12 16:53:18 peter
* moved entry and exitcode to ncgutil and cgobj
* foreach gets extra argument for passing local data to the
iterator function
* -CR checks also class typecasts at runtime by changing them
into as
* fixed compiler to cycle with the -CR option
* fixed stabs with elf writer, finally the global variables can
be watched
* removed a lot of routines from cga unit and replaced them by
calls to cgobj
* u32bit-s32bit updates for and,or,xor nodes. When one element is
u32bit then the other is typecasted also to u32bit without giving
a rangecheck warning/error.
* fixed pascal calling method with reversing also the high tree in
the parast, detected by tcalcst3 test
Revision 1.23 2002/04/21 15:40:49 carl
* changeregsize -> changeregsize
Revision 1.22 2002/04/20 21:37:07 carl
+ generic FPC_CHECKPOINTER
+ first parameter offset in stack now portable
* rename some constants
+ move some cpu stuff to other units
- remove unused constents
* fix stacksize for some targets
* fix generic size problems which depend now on EXTEND_SIZE constant
* removing frame pointer in routines is only available for : i386,m68k and vis targets
Revision 1.21 2002/04/15 19:44:21 peter
* fixed stackcheck that would be called recursively when a stack
error was found
* generic changeregsize(reg,size) for i386 register resizing
* removed some more routines from cga unit
* fixed returnvalue handling
* fixed default stacksize of linux and go32v2, 8kb was a bit small :-)
Revision 1.20 2002/04/02 20:30:16 jonas
+ support for folding inc/dec in shl/add/sub sequences toa single lea
instruction
Revision 1.19 2002/04/02 13:01:58 jonas
* fixed nasty bug in "and" peepholeoptimization that caused wrong
optimizations after Peter's big location patch
Revision 1.18 2002/03/31 20:26:40 jonas
+ a_loadfpu_* and a_loadmm_* methods in tcg
* register allocation is now handled by a class and is mostly processor
independent (+rgobj.pas and i386/rgcpu.pas)
* temp allocation is now handled by a class (+tgobj.pas, -i386\tgcpu.pas)
* some small improvements and fixes to the optimizer
* some register allocation fixes
* some fpuvaroffset fixes in the unary minus node
* push/popusedregisters is now called rg.save/restoreusedregisters and
(for i386) uses temps instead of push/pop's when using -Op3 (that code is
also better optimizable)
* fixed and optimized register saving/restoring for new/dispose nodes
* LOC_FPU locations now also require their "register" field to be set to
R_ST, not R_ST0 (the latter is used for LOC_CFPUREGISTER locations only)
- list field removed of the tnode class because it's not used currently
and can cause hard-to-find bugs
}