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


On Fri, Jul 4, 2014 at 10:36 AM, Bin.Cheng <amker.cheng@gmail.com> 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?

Yes, since there have been no other issues reported. Can either of you
also update PR61544 with the fields for Known to Work and Known to
fail setting a target milestone of GCC 4.9.1 rather than leaving these
fields empty.

Ramana

>
> Thanks,
> bin


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