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+ change "mov var,reg; add/shr/... x,reg; mov reg,var" to

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"add/shr/... x,var" (if x is a const or reg, suggestion from Peter)
    Enable with -dfoldArithOps
This commit is contained in:
Jonas Maebe 1999-11-27 23:47:55 +00:00
parent ff017bbd5f
commit e250138c67
1 changed files with 63 additions and 2 deletions
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65
compiler/popt386.pas
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@ -1561,14 +1561,34 @@ Begin
end;
end;
{$ifdef foldArithOps}
Function IsArithOp(opcode: TAsmOp): Boolean;
Begin
IsArithOp := False;
Case opcode Of
A_ADD,A_SUB,A_OR,A_XOR,A_AND,A_SHL,A_SHR,A_SAR: IsArithOp := True
End;
End;
{$endif foldArithOps}
Procedure PeepHoleOptPass2(AsmL: PAasmOutput; BlockStart, BlockEnd: Pai);
var
p,hp1,hp2: pai;
{$ifdef foldArithOps}
UsedRegs, TmpUsedRegs: TRegSet;
{$endif foldArithOps}
Begin
P := BlockStart;
{$ifdef foldArithOps}
UsedRegs := [];
{$endif foldArithOps}
While (P <> BlockEnd) Do
Begin
{$ifdef foldArithOps}
UpdateUsedRegs(UsedRegs, Pai(p^.next));
{$endif foldArithOps}
Case P^.Typ Of
Ait_Instruction:
Begin
@ -1612,7 +1632,43 @@ Begin
Dispose(p, Done);
p := hp1;
Continue;
End;
End
{$ifdef foldArithOps}
Else If (Paicpu(p)^.oper[0].typ = top_ref) And
GetNextInstruction(p,hp1) And
(hp1^.typ = ait_instruction) And
IsArithOp(Paicpu(hp1)^.opcode) And
(Paicpu(hp1)^.oper[0].typ in [top_reg,top_const]) And
(Paicpu(hp1)^.oper[1].typ = top_reg) And
(Paicpu(hp1)^.oper[1].reg = Paicpu(p)^.oper[1].reg) And
GetNextInstruction(hp1,hp2) And
(hp2^.typ = ait_instruction) And
(Paicpu(hp2)^.opcode = A_MOV) And
(Paicpu(hp2)^.oper[0].typ = top_reg) And
(Paicpu(hp2)^.oper[0].reg = Paicpu(p)^.oper[1].reg) And
(Paicpu(hp2)^.oper[1].typ = top_ref) Then
Begin
TmpUsedRegs := UsedRegs;
UpdateUsedRegs(TmpUsedRegs,Pai(hp1^.next));
If (RefsEqual(Paicpu(hp2)^.oper[1].ref^, Paicpu(p)^.oper[0].ref^) And
Not(RegUsedAfterInstruction(Reg32(Paicpu(p)^.oper[1].reg),
hp2, TmpUsedRegs)))
Then
{ change mov (ref), reg }
{ add/sub/or/... reg2/$const, reg }
{ mov (reg), ref }
{ # relaese reg }
{ to add/sub/or/... reg2/$const, (ref) }
Begin
Paicpu(hp1)^.LoadRef(1,newreference(Paicpu(p)^.oper[0].ref^));
AsmL^.Remove(p);
AsmL^.Remove(hp2);
Dispose(p,done);
Dispose(hp2,Done);
p := hp1
End;
End;
{$endif foldArithOps}
End;
A_MOVZX:
Begin
@ -1672,7 +1728,12 @@ End.
{
$Log$
Revision 1.70 1999-11-21 13:09:41 jonas
Revision 1.71 1999-11-27 23:47:55 jonas
+ change "mov var,reg; add/shr/... x,reg; mov reg,var" to
"add/shr/... x,var" (if x is a const or reg, suggestion from Peter)
Enable with -dfoldArithOps
Revision 1.70 1999/11/21 13:09:41 jonas
* fixed some missed optimizations because 8bit regs were not always
taken into account