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Rerun peephole optimizers on the whole block
Up until now if a peephole optimizer matched we've only restarted from the current instruction. This patch restarts optimizations on the whole block if the previous run had at least one match. As this can take considerable time this will only be enabled if -O3 or higher is specified. git-svn-id: trunk@26640 -
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masta
parent
4fa8998541
commit
81517fdf70
@ -1306,130 +1306,138 @@ Unit AoptObj;
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procedure TAOptObj.PeepHoleOptPass1;
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var
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p,hp1,hp2 : tai;
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stoploop:boolean;
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begin
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p := BlockStart;
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ClearUsedRegs;
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while (p <> BlockEnd) Do
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begin
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{ I'am not sure why this is done, UsedRegs should reflect the register usage before the instruction
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If an instruction needs the information of this, it can easily create a TempUsedRegs (FK)
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UpdateUsedRegs(tai(p.next));
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}
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{$ifdef DEBUG_OPTALLOC}
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if p.Typ=ait_instruction then
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InsertLLItem(tai(p.Previous),p,tai_comment.create(strpnew(GetAllocationString(UsedRegs))));
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{$endif DEBUG_OPTALLOC}
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if PeepHoleOptPass1Cpu(p) then
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begin
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UpdateUsedRegs(p);
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continue;
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end;
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case p.Typ Of
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ait_instruction:
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repeat
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stoploop:=true;
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p := BlockStart;
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ClearUsedRegs;
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while (p <> BlockEnd) Do
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begin
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{ I'am not sure why this is done, UsedRegs should reflect the register usage before the instruction
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If an instruction needs the information of this, it can easily create a TempUsedRegs (FK)
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UpdateUsedRegs(tai(p.next));
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}
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{$ifdef DEBUG_OPTALLOC}
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if p.Typ=ait_instruction then
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InsertLLItem(tai(p.Previous),p,tai_comment.create(strpnew(GetAllocationString(UsedRegs))));
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{$endif DEBUG_OPTALLOC}
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if PeepHoleOptPass1Cpu(p) then
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begin
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{ Handle Jmp Optimizations }
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if taicpu(p).is_jmp then
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begin
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{ the following if-block removes all code between a jmp and the next label,
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because it can never be executed
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}
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if IsJumpToLabel(taicpu(p)) then
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begin
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hp2:=p;
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while GetNextInstruction(hp2, hp1) and
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(hp1.typ <> ait_label) do
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if not(hp1.typ in ([ait_label,ait_align]+skipinstr)) then
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begin
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if (hp1.typ = ait_instruction) and
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taicpu(hp1).is_jmp and
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(JumpTargetOp(taicpu(hp1))^.typ = top_ref) and
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(JumpTargetOp(taicpu(hp1))^.ref^.symbol is TAsmLabel) then
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TAsmLabel(JumpTargetOp(taicpu(hp1))^.ref^.symbol).decrefs;
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{ don't kill start/end of assembler block,
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no-line-info-start/end etc }
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if hp1.typ<>ait_marker then
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begin
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{$if defined(SPARC) or defined(MIPS) }
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if (hp1.typ=ait_instruction) and (taicpu(hp1).is_jmp) then
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RemoveDelaySlot(hp1);
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{$endif SPARC or MIPS }
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asml.remove(hp1);
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hp1.free;
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end
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else
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hp2:=hp1;
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end
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else break;
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end;
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{ remove jumps to a label coming right after them }
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if GetNextInstruction(p, hp1) then
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begin
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SkipEntryExitMarker(hp1,hp1);
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if FindLabel(tasmlabel(JumpTargetOp(taicpu(p))^.ref^.symbol), hp1) and
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{ TODO: FIXME removing the first instruction fails}
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(p<>blockstart) then
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begin
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tasmlabel(JumpTargetOp(taicpu(p))^.ref^.symbol).decrefs;
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{$if defined(SPARC) or defined(MIPS)}
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RemoveDelaySlot(p);
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{$endif SPARC or MIPS}
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hp2:=tai(hp1.next);
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asml.remove(p);
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p.free;
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p:=hp2;
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continue;
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end
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else if assigned(hp1) then
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begin
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if hp1.typ = ait_label then
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SkipLabels(hp1,hp1);
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if (tai(hp1).typ=ait_instruction) and
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IsJumpToLabel(taicpu(hp1)) and
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GetNextInstruction(hp1, hp2) and
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FindLabel(tasmlabel(JumpTargetOp(taicpu(p))^.ref^.symbol), hp2) then
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stoploop:=false;
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UpdateUsedRegs(p);
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continue;
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end;
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case p.Typ Of
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ait_instruction:
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begin
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{ Handle Jmp Optimizations }
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if taicpu(p).is_jmp then
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begin
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{ the following if-block removes all code between a jmp and the next label,
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because it can never be executed
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}
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if IsJumpToLabel(taicpu(p)) then
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begin
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hp2:=p;
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while GetNextInstruction(hp2, hp1) and
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(hp1.typ <> ait_label) do
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if not(hp1.typ in ([ait_label,ait_align]+skipinstr)) then
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begin
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if (taicpu(p).opcode=aopt_condjmp)
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{$ifdef arm}
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and (taicpu(p).condition<>C_None)
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{$endif arm}
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then
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if (hp1.typ = ait_instruction) and
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taicpu(hp1).is_jmp and
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(JumpTargetOp(taicpu(hp1))^.typ = top_ref) and
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(JumpTargetOp(taicpu(hp1))^.ref^.symbol is TAsmLabel) then
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TAsmLabel(JumpTargetOp(taicpu(hp1))^.ref^.symbol).decrefs;
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{ don't kill start/end of assembler block,
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no-line-info-start/end etc }
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if hp1.typ<>ait_marker then
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begin
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taicpu(p).condition:=inverse_cond(taicpu(p).condition);
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tai_label(hp2).labsym.decrefs;
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JumpTargetOp(taicpu(p))^.ref^.symbol:=JumpTargetOp(taicpu(hp1))^.ref^.symbol;
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{ when freeing hp1, the reference count
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isn't decreased, so don't increase
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taicpu(p).oper[0]^.ref^.symbol.increfs;
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}
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{$if defined(SPARC) or defined(MIPS)}
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RemoveDelaySlot(hp1);
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{$endif SPARC or MIPS}
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{$if defined(SPARC) or defined(MIPS) }
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if (hp1.typ=ait_instruction) and (taicpu(hp1).is_jmp) then
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RemoveDelaySlot(hp1);
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{$endif SPARC or MIPS }
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asml.remove(hp1);
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hp1.free;
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GetFinalDestination(taicpu(p),0);
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stoploop:=false;
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end
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else
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begin
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GetFinalDestination(taicpu(p),0);
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p:=tai(p.next);
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continue;
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end;
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hp2:=hp1;
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end
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else
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GetFinalDestination(taicpu(p),0);
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else break;
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end;
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end;
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end
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else
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{ All other optimizes }
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begin
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end; { if is_jmp }
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end;
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{ remove jumps to a label coming right after them }
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if GetNextInstruction(p, hp1) then
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begin
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SkipEntryExitMarker(hp1,hp1);
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if FindLabel(tasmlabel(JumpTargetOp(taicpu(p))^.ref^.symbol), hp1) and
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{ TODO: FIXME removing the first instruction fails}
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(p<>blockstart) then
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begin
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tasmlabel(JumpTargetOp(taicpu(p))^.ref^.symbol).decrefs;
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{$if defined(SPARC) or defined(MIPS)}
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RemoveDelaySlot(p);
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{$endif SPARC or MIPS}
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hp2:=tai(hp1.next);
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asml.remove(p);
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p.free;
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p:=hp2;
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stoploop:=false;
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continue;
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end
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else if assigned(hp1) then
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begin
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if hp1.typ = ait_label then
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SkipLabels(hp1,hp1);
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if (tai(hp1).typ=ait_instruction) and
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IsJumpToLabel(taicpu(hp1)) and
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GetNextInstruction(hp1, hp2) and
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FindLabel(tasmlabel(JumpTargetOp(taicpu(p))^.ref^.symbol), hp2) then
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begin
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if (taicpu(p).opcode=aopt_condjmp)
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{$ifdef arm}
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and (taicpu(p).condition<>C_None)
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{$endif arm}
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then
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begin
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taicpu(p).condition:=inverse_cond(taicpu(p).condition);
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tai_label(hp2).labsym.decrefs;
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JumpTargetOp(taicpu(p))^.ref^.symbol:=JumpTargetOp(taicpu(hp1))^.ref^.symbol;
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{ when freeing hp1, the reference count
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isn't decreased, so don't increase
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taicpu(p).oper[0]^.ref^.symbol.increfs;
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}
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{$if defined(SPARC) or defined(MIPS)}
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RemoveDelaySlot(hp1);
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{$endif SPARC or MIPS}
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asml.remove(hp1);
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hp1.free;
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stoploop:=false;
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GetFinalDestination(taicpu(p),0);
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end
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else
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begin
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GetFinalDestination(taicpu(p),0);
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p:=tai(p.next);
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continue;
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end;
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end
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else
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GetFinalDestination(taicpu(p),0);
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end;
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end;
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end
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else
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{ All other optimizes }
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begin
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end; { if is_jmp }
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end;
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end;
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UpdateUsedRegs(p);
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p:=tai(p.next);
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end;
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UpdateUsedRegs(p);
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p:=tai(p.next);
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end;
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until stoploop or not(cs_opt_level3 in current_settings.optimizerswitches);
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end;
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