paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-04-15 19:19:24 +02:00
Code Issues Packages Projects Releases Wiki Activity

+ SETcc/Mov -> SETcc optimization

Browse Source 
git-svn-id: trunk@48808 -
This commit is contained in:
florian 2021-02-25 22:07:40 +00:00
parent 857cbddf04
commit c6443809ba
1 changed files with 75 additions and 59 deletions

134
compiler/x86/aoptx86.pas
View File

@ -3991,76 +3991,92 @@ unit aoptx86;
begin
Result:=false;
if MatchOpType(taicpu(p),top_reg) and
GetNextInstruction(p, hp1) and
((MatchInstruction(hp1, A_TEST, [S_B]) and
MatchOpType(taicpu(hp1),top_reg,top_reg) and
(taicpu(hp1).oper[0]^.reg = taicpu(hp1).oper[1]^.reg)) or
(MatchInstruction(hp1, A_CMP, [S_B]) and
MatchOpType(taicpu(hp1),top_const,top_reg) and
(taicpu(hp1).oper[0]^.val=0))
) and
(taicpu(p).oper[0]^.reg = taicpu(hp1).oper[1]^.reg) and
GetNextInstruction(hp1, hp2) and
MatchInstruction(hp2, A_Jcc, []) then
{ Change from: To:
set(C) %reg j(~C) label
test %reg,%reg/cmp $0,%reg
je label
set(C) %reg j(C) label
test %reg,%reg/cmp $0,%reg
jne label
}
if MatchOpType(taicpu(p),top_reg) and GetNextInstruction(p, hp1) then
begin
next := tai(p.Next);
if ((MatchInstruction(hp1, A_TEST, [S_B]) and
MatchOpType(taicpu(hp1),top_reg,top_reg) and
(taicpu(hp1).oper[0]^.reg = taicpu(hp1).oper[1]^.reg)) or
(MatchInstruction(hp1, A_CMP, [S_B]) and
MatchOpType(taicpu(hp1),top_const,top_reg) and
(taicpu(hp1).oper[0]^.val=0))
) and
(taicpu(p).oper[0]^.reg = taicpu(hp1).oper[1]^.reg) and
GetNextInstruction(hp1, hp2) and
MatchInstruction(hp2, A_Jcc, []) then
{ Change from: To:
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegs(TmpUsedRegs, next);
UpdateUsedRegs(TmpUsedRegs, tai(hp1.next));
set(C) %reg j(~C) label
test %reg,%reg/cmp $0,%reg
je label
JumpC := taicpu(hp2).condition;
Unconditional := False;
if conditions_equal(JumpC, C_E) then
SetC := inverse_cond(taicpu(p).condition)
else if conditions_equal(JumpC, C_NE) then
SetC := taicpu(p).condition
else
{ We've got something weird here (and inefficent) }
set(C) %reg j(C) label
test %reg,%reg/cmp $0,%reg
jne label
}
begin
DebugMsg('DEBUG: Inefficient jump - check code generation', p);
SetC := C_NONE;
next := tai(p.Next);
{ JAE/JNB will always branch (use 'condition_in', since C_AE <> C_NB normally) }
if condition_in(C_AE, JumpC) then
Unconditional := True
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegs(TmpUsedRegs, next);
UpdateUsedRegs(TmpUsedRegs, tai(hp1.next));
JumpC := taicpu(hp2).condition;
Unconditional := False;
if conditions_equal(JumpC, C_E) then
SetC := inverse_cond(taicpu(p).condition)
else if conditions_equal(JumpC, C_NE) then
SetC := taicpu(p).condition
else
{ Not sure what to do with this jump - drop out }
Exit;
end;
{ We've got something weird here (and inefficent) }
begin
DebugMsg('DEBUG: Inefficient jump - check code generation', p);
SetC := C_NONE;
RemoveInstruction(hp1);
{ JAE/JNB will always branch (use 'condition_in', since C_AE <> C_NB normally) }
if condition_in(C_AE, JumpC) then
Unconditional := True
else
{ Not sure what to do with this jump - drop out }
Exit;
end;
if Unconditional then
MakeUnconditional(taicpu(hp2))
else
RemoveInstruction(hp1);
if Unconditional then
MakeUnconditional(taicpu(hp2))
else
begin
if SetC = C_NONE then
InternalError(2018061402);
taicpu(hp2).SetCondition(SetC);
end;
if not RegUsedAfterInstruction(taicpu(p).oper[0]^.reg, hp2, TmpUsedRegs) then
begin
RemoveCurrentp(p, hp2);
Result := True;
end;
DebugMsg(SPeepholeOptimization + 'SETcc/TESTCmp/Jcc -> Jcc',p);
end
else if MatchInstruction(hp1, A_MOV, [S_B]) and
MatchOpType(taicpu(hp1),top_reg,top_reg) and
MatchOperand(taicpu(p).oper[0]^,taicpu(hp1).oper[0]^) then
begin
if SetC = C_NONE then
InternalError(2018061402);
taicpu(hp2).SetCondition(SetC);
TransferUsedRegs(TmpUsedRegs);
UpdateUsedRegs(TmpUsedRegs, tai(p.Next));
if not RegUsedAfterInstruction(taicpu(p).oper[0]^.reg, hp1, TmpUsedRegs) then
begin
AllocRegBetween(taicpu(p).oper[0]^.reg,p,hp1,UsedRegs);
taicpu(p).oper[0]^.reg:=taicpu(hp1).oper[1]^.reg;
RemoveInstruction(hp1);
DebugMsg(SPeepholeOptimization + 'SETcc/Mov -> SETcc',p);
Result := true;
end;
end;
if not RegUsedAfterInstruction(taicpu(p).oper[0]^.reg, hp2, TmpUsedRegs) then
begin
RemoveCurrentp(p, hp2);
Result := True;
end;
DebugMsg(SPeepholeOptimization + 'SETcc/TESTCmp/Jcc -> Jcc',p);
end;
end;