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+ X86: JccMovJmpMov2MovSetcc optimization

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git-svn-id: trunk@48993 -
This commit is contained in:
florian 2021-03-16 22:19:21 +00:00
parent b9b08f37fe
commit 53effea0f5
2 changed files with 73 additions and 1 deletions
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2
compiler/aoptobj.pas
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@ -1400,6 +1400,8 @@ Unit AoptObj;
reg:=newreg(R_FPUREGISTER,getsupreg(reg),R_SUBWHOLE);
R_ADDRESSREGISTER:
reg:=newreg(R_ADDRESSREGISTER,getsupreg(reg),R_SUBWHOLE);
R_SPECIALREGISTER:
reg:=newreg(R_SPECIALREGISTER,getsupreg(reg),R_SUBWHOLE);
else
Internalerror(2018030701);
end;

72
compiler/x86/aoptx86.pas
View File

@ -5867,7 +5867,7 @@ unit aoptx86;
var
hp1,hp2: tai;
{$ifndef i8086}
hp3,hp4,hpmov2: tai;
hp3,hp4,hpmov2, hp5: tai;
l : Longint;
condition : TAsmCond;
{$endif i8086}
@ -6084,6 +6084,76 @@ unit aoptx86;
end;
{$ifndef i8086}
end
{
convert
j<c> .L1
mov 1,reg
jmp .L2
.L1
mov 0,reg
.L2
into
mov 0,reg
set<not(c)> reg
take care of alignment and that the mov 0,reg is not converted into a xor as this
would destroy the flag contents
}
else if MatchInstruction(hp1,A_MOV,[]) and
MatchOpType(taicpu(hp1),top_const,top_reg) and
{$ifdef i386}
(
{ Under i386, ESI, EDI, EBP and ESP
don't have an 8-bit representation }
not (getsupreg(taicpu(hp1).oper[1]^.reg) in [RS_ESI, RS_EDI, RS_EBP, RS_ESP])
) and
{$endif i386}
(taicpu(hp1).oper[0]^.val=1) and
GetNextInstruction(hp1,hp2) and
MatchInstruction(hp2,A_JMP,[]) and (taicpu(hp2).oper[0]^.ref^.refaddr=addr_full) and
GetNextInstruction(hp2,hp3) and
{ skip align }
((hp3.typ<>ait_align) or GetNextInstruction(hp3,hp3)) and
(hp3.typ=ait_label) and
(tasmlabel(taicpu(p).oper[0]^.ref^.symbol)=tai_label(hp3).labsym) and
(tai_label(hp3).labsym.getrefs=1) and
GetNextInstruction(hp3,hp4) and
MatchInstruction(hp4,A_MOV,[]) and
MatchOpType(taicpu(hp4),top_const,top_reg) and
(taicpu(hp4).oper[0]^.val=0) and
MatchOperand(taicpu(hp1).oper[1]^,taicpu(hp4).oper[1]^) and
GetNextInstruction(hp4,hp5) and
(hp5.typ=ait_label) and
(tasmlabel(taicpu(hp2).oper[0]^.ref^.symbol)=tai_label(hp5).labsym) and
(tai_label(hp5).labsym.getrefs=1) then
begin
AllocRegBetween(NR_FLAGS,p,hp4,UsedRegs);
DebugMsg(SPeepholeOptimization+'JccMovJmpMov2MovSetcc',p);
{ remove last label }
RemoveInstruction(hp5);
{ remove second albel }
RemoveInstruction(hp3);
{ if align is present remove it }
if GetNextInstruction(hp2,hp3) and (hp3.typ=ait_align) then
RemoveInstruction(hp3);
{ remove jmp }
RemoveInstruction(hp2);
if taicpu(hp1).opsize=S_B then
RemoveInstruction(hp1)
else
taicpu(hp1).loadconst(0,0);
taicpu(hp4).opcode:=A_SETcc;
taicpu(hp4).opsize:=S_B;
taicpu(hp4).condition:=inverse_cond(taicpu(p).condition);
taicpu(hp4).loadreg(0,newreg(R_INTREGISTER,getsupreg(taicpu(hp4).oper[1]^.reg),R_SUBL));
taicpu(hp4).opercnt:=1;
taicpu(hp4).ops:=1;
taicpu(hp4).freeop(1);
RemoveCurrentP(p);
Result:=true;
exit;
end
else if CPUX86_HAS_CMOV in cpu_capabilities[current_settings.cputype] then
begin
{ check for