I'm tring this function, but it have some problems. It seems not link
the new insn in the double-list.

void merge(rtx insn1,rtx insn2)
{
        rtx par, pre,sur, insn;

        par = gen_rtx_PARALLEL (SFmode, rtvec_alloc (2));

        XVECEXP (par, 0, 0) = PATTERN(insn1);
        XVECEXP (par, 0, 1) = PATTERN(insn2);

        insn = make_insn_raw (par);

        sur = NEXT_INSN(insn1);

        PREV_INSN(insn) = insn1;
        NEXT_INSN(insn) = sur;
        delete_insn(insn1);

        delete_insn(insn2);
}


2009/12/11 daniel tian <daniel.xnt...@gmail.com>:
> 2009/12/11 Ian Lance Taylor <i...@google.com>:
>> daniel tian <daniel.xnt...@gmail.com> writes:
>>
>>>     I have a problem about RTL sequence.
>>>     If I wanna generate the RTL in sequence, and don't let gcc to schedule 
>>> them.
>>>     Like the following(all the variable is rtx):
>>>
>>>     emit_insn(reg0,  operands[0]);
>>>     emit_insn(reg1,  reg0);
>>>     emit_insn(operands[0],  reg1);
>>>
>>>     But gcc will will reorder the three rtl in optimization.
>>>     I just wanna the those rtl in one block as a unit, don't let the
>>> gcc disrupt the sequence.
>>>     How can I do it?
>>
>> Write a single define_insn which emits the instructions you want to
>> treat as a unit.
>>
>
> Does there any solution in RTL level?
> Because I already solve the problem in ASM output level,  exactly the
> same solution as you suggest in this email.
> I may need do some optimization later. So RTL level will be great!
>
> Thanks for your advice.
> Best Regards.
>
>                             daniel.tian
>



-- 
Jianzhang Peng

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