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* x86: New RET/lbl/RET optimisation

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This commit is contained in:
J. Gareth "Curious Kit" Moreton 2022-11-15 08:53:10 +00:00 committed by FPK
parent 8bb3367a49
commit 8520dabebb
4 changed files with 44 additions and 0 deletions
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2
compiler/i386/aoptcpu.pas
View File

@ -434,6 +434,8 @@ unit aoptcpu;
Result:=PostPeepholeOptADDSUB(p);
A_XOR:
Result:=PostPeepholeOptXor(p);
A_RET:
Result:=PostPeepholeOptRET(p);
A_VPXOR:
Result:=PostPeepholeOptVPXOR(p);
else

2
compiler/i8086/aoptcpu.pas
View File

@ -162,6 +162,8 @@ unit aoptcpu;
A_OR,
A_TEST:
Result:=PostPeepholeOptTestOr(p);
A_RET:
Result:=PostPeepholeOptRET(p);
else
;
end;

38
compiler/x86/aoptx86.pas
View File

@ -224,6 +224,7 @@ unit aoptx86;
function PostPeepholeOptShr(var p : tai) : boolean;
function PostPeepholeOptADDSUB(var p : tai) : Boolean;
function PostPeepholeOptVPXOR(var p: tai): Boolean;
function PostPeepholeOptRET(var p: tai): Boolean;
procedure ConvertJumpToRET(const p: tai; const ret_p: tai);
@ -17549,6 +17550,43 @@ unit aoptx86;
end;
function TX86AsmOptimizer.PostPeepholeOptRET(var p: tai): Boolean;
var
hp1, p_new: tai;
begin
Result := False;
{ Check for:
ret
.Lbl:
ret
Remove first 'ret'
}
if GetNextInstruction(p, hp1) and
{ Remember where the label is }
SetAndTest(hp1, p_new) and
(hp1.typ in [ait_align, ait_label]) and
SkipLabels(hp1, hp1) and
MatchInstruction(hp1, A_RET, []) and
{ To be safe, make sure the RET instructions are identical }
(taicpu(p).ops = taicpu(hp1).ops) and
(
(taicpu(p).ops = 0) or
(
(taicpu(p).ops = 1) and
MatchOperand(taicpu(p).oper[0]^, taicpu(hp1).oper[0]^)
)
) then
begin
DebugMsg(SPeepholeOptimization + 'Removed superfluous RET', p);
UpdateUsedRegs(tai(p.Next));
RemoveCurrentP(p, p_new);
Result := True;
Exit;
end;
end;
class procedure TX86AsmOptimizer.OptimizeRefs(var p: taicpu);
var
OperIdx: Integer;

2
compiler/x86_64/aoptcpu.pas
View File

@ -302,6 +302,8 @@ uses
A_ADD,
A_SUB:
Result:=PostPeepholeOptADDSUB(p);
A_RET:
Result:=PostPeepholeOptRET(p);
A_VPXOR:
Result:=PostPeepholeOptVPXOR(p);
else