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* patch by J. Gareth Moreton: x86: Minor bitwise optimisations, resolves

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git-svn-id: trunk@49614 -
This commit is contained in:
florian 2021-07-16 21:47:36 +00:00
parent 2a2576b1d5
commit c67d35b8cc
3 changed files with 51 additions and 0 deletions

2
compiler/i386/aoptcpu.pas
View File

@ -100,6 +100,8 @@ unit aoptcpu;
Result:=PrePeepholeOptIMUL(p);
A_SAR,A_SHR:
Result:=PrePeepholeOptSxx(p);
A_AND:
Result:=PrePeepholeOptAND(p);
A_XOR:
begin
if (taicpu(p).oper[0]^.typ = top_reg) and

47
compiler/x86/aoptx86.pas
View File

@ -127,6 +127,7 @@ unit aoptx86;
function PrePeepholeOptSxx(var p : tai) : boolean;
function PrePeepholeOptIMUL(var p : tai) : boolean;
function PrePeepholeOptAND(var p : tai) : boolean;
function OptPass1Test(var p: tai): boolean;
function OptPass1Add(var p: tai): boolean;
@ -1215,6 +1216,19 @@ unit aoptx86;
end;
function TX86AsmOptimizer.PrePeepholeOptAND(var p : tai) : boolean;
begin
Result := False;
if MatchOperand(taicpu(p).oper[0]^, 0) and
not RegInUsedRegs(NR_DEFAULTFLAGS, UsedRegs) then
begin
DebugMsg(SPeepholeOptimization + 'AND 0 -> MOV 0', p);
taicpu(p).opcode := A_MOV;
Result := True;
end;
end;
function TX86AsmOptimizer.RegLoadedWithNewValue(reg: tregister; hp: tai): boolean;
var
p: taicpu absolute hp;
@ -2594,6 +2608,39 @@ unit aoptx86;
end;
end;
end;
if (taicpu(hp1).opcode = A_OR) and
(taicpu(p).oper[1]^.typ = top_reg) and
MatchOperand(taicpu(p).oper[0]^, 0) and
MatchOperand(taicpu(hp1).oper[1]^, taicpu(p).oper[1]^.reg) then
begin
{ mov 0, %reg
or ###,%reg
Change to (only if the flags are not used):
mov ###,%reg
}
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegs(TmpUsedRegs, tai(p.Next));
if not (RegInUsedRegs(NR_DEFAULTFLAGS, TmpUsedRegs)) then
begin
{$ifdef x86_64}
{ OR only supports 32-bit sign-extended constants for 64-bit
instructions, so compensate for this if the constant is
encoded as a value greater than or equal to 2^31 }
if (taicpu(hp1).opsize = S_Q) and
(taicpu(hp1).oper[0]^.typ = top_const) and
(taicpu(hp1).oper[0]^.val >= $80000000) then
taicpu(hp1).oper[0]^.val := taicpu(hp1).oper[0]^.val or $FFFFFFFF00000000;
{$endif x86_64}
DebugMsg(SPeepholeOptimization + 'MOV 0 / OR -> MOV', p);
taicpu(hp1).opcode := A_MOV;
RemoveCurrentP(p, hp1);
Result := True;
Exit;
end;
end;
{ Next instruction is also a MOV ? }
if MatchInstruction(hp1,A_MOV,[taicpu(p).opsize]) then
begin

2
compiler/x86_64/aoptcpu.pas
View File

@ -54,6 +54,8 @@ uses
result:=PrePeepholeOptIMUL(p);
A_SAR,A_SHR:
result:=PrePeepholeOptSxx(p);
A_AND:
Result:=PrePeepholeOptAND(p);
else
;
end;