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Re: [Patch, GCC/Thumb-1]Mishandle the label type insn in function thumb1_reorg


On 04/07/14 10:36, Bin.Cheng wrote:
> On Wed, Jun 18, 2014 at 10:16 AM, Terry Guo <terry.guo@arm.com> wrote:
>>
>>
>>> -----Original Message-----
>>> From: Richard Earnshaw
>>> Sent: Wednesday, June 18, 2014 4:31 PM
>>> To: Terry Guo
>>> Cc: gcc-patches@gcc.gnu.org; Ramana Radhakrishnan
>>> Subject: Re: [Patch, GCC/Thumb-1]Mishandle the label type insn in function
>>> thumb1_reorg
>>>
>>> On 10/06/14 12:42, Terry Guo wrote:
>>>> Hi There,
>>>>
>>>> The thumb1_reorg function use macro INSN_CODE to find expected
>>> instructions.
>>>> But the macro INSN_CODE doesn't work for label type instruction. The
>>>> INSN_CODE(label_insn) will return the label number. When we have a lot
>>> of
>>>> labels and current label_insn is the first insn of basic block, the
>>>> INSN_CODE(label_insn) could accidentally equal to
>>> CODE_FOR_cbranchsi4_insn
>>>> in this case. This leads to ICE due to SET_SRC(label_insn) in subsequent
>>>> code. In general we should skip all such improper insns. This is the purpose
>>>> of attached small patch.
>>>>
>>>> Some failures in recent gcc regression test on thumb1 target are caused by
>>>> this reason. So with this patch, all of them passed and no new failures. Is
>>>> it ok to trunk?
>>>>
>>>> BR,
>>>> Terry
>>>>
>>>> 2014-06-10  Terry Guo  <terry.guo@arm.com>
>>>>
>>>>      * config/arm/arm.c (thumb1_reorg): Move to next basic block if the
>>> head
>>>>      of current basic block isn't a proper insn.
>>>>
>>>
>>> I think you should just test that "insn != BB_HEAD (bb)".  The loop
>>> immediately above this deals with the !NON-DEBUG insns, so the logic is
>>> confusing the way you've written it.
>>>
>>> R.
>>>
>>
>> Thanks for comments. The patch is updated and tested. No more ICE. Is this one OK?
>>
>> BR,
>> Terry
> 
> Hi,
> The bug is also reported for 4.9 branch at
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61712
> As far as I checked, the ICE is also caused by label instruction as in
> this message thread.
> Since the fix is on trunk more than two weeks, could we back port it
> to 4.9 branch?
> 
> Thanks,
> bin
> 

Yes, unless an RM objects within 24 hours.

R.



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