llvm dev - Jul 2017 - Tail merging "undef" with a defined register: wrong code

On 7/28/2017 4:00 PM, Quentin Colombet wrote:
> I am having a hard time seeing the problem from the example, shouldn’t 
> we just put an implicit_def at the end of bb.0?
That should work actually, even in the general case. I overlooked 
something when I first said it wouldn't.

-Krzysztof

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> On Jul 28, 2017, at 2:17 PM, Krzysztof Parzyszek <kparzysz at
codeaurora.org> wrote:
> 
> On 7/28/2017 4:00 PM, Quentin Colombet wrote:
>> I am having a hard time seeing the problem from the example, shouldn’t
we just put an implicit_def at the end of bb.0?
> 
> That should work actually, even in the general case. I overlooked something
when I first said it wouldn’t.
Great!
> 
> -Krzysztof
> 
> -- 
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted
by The Linux Foundation

I ran into the LR/PC issue on ARM again, and the patch has some approach 
to fixing it.  I'm wondering what you think.
https://reviews.llvm.org/D36160

-Krzysztof

On 7/28/2017 5:13 PM, Quentin Colombet wrote:
> 
>> On Jul 28, 2017, at 2:17 PM, Krzysztof Parzyszek <kparzysz at
codeaurora.org> wrote:
>>
>> On 7/28/2017 4:00 PM, Quentin Colombet wrote:
>>> I am having a hard time seeing the problem from the example,
shouldn’t we just put an implicit_def at the end of bb.0?
>>
>> That should work actually, even in the general case. I overlooked
something when I first said it wouldn’t.
> 
> Great!
> 
>>
>> -Krzysztof
>>
>> -- 
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
> 
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, 
hosted by The Linux Foundation