[polly] r261474 - [FIX] Compare SCEVs not values during SCEV expansion

[Tobias Grosser via llvm-commits]

On 02/21/2016 08:14 PM, Tobias Grosser via llvm-commits wrote:
> On 02/21/2016 07:42 PM, Johannes Doerfert wrote:
>> On 02/21, Tobias Grosser wrote:
>>> On 02/21/2016 07:16 PM, Johannes Doerfert wrote:
>>>>> On 02/21/2016 05:36 PM, Johannes Doerfert via llvm-commits wrote:
>>>>>> Author: jdoerfert
>>>>>> Date: Sun Feb 21 10:36:00 2016
>>>>>> New Revision: 261474
>>>>>>
>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=261474&view=rev
>>>>>> Log:
>>>>>> [FIX] Compare SCEVs not values during SCEV expansion
>>>>>>
>>>>>>    This fixes a compile time bug in SPEC2006 403.gcc, namely an
>>>>>> endless
>>>>>>    recursion in the ScopExpander::visitUnknown function.
>>>>>
>>>>> A test case would be good. Was there  a specific reason you could
>>>>> not add a
>>>>> test case?
>>>> I tried but could not generate one. Only when I run it with clang I
>>>> triggered the problem. Tried to extract the module as Polly sees it but
>>>> it didn't help.
>>>
>>> How did you extract the code from clang?
>> I dumped the Module in ScopInfo for the original command line. But I
>> still could not reproduce the behaviour afterwards (opt -O3 -polly on
>> the module).
>
> This may also result in different IR reaching Polly. Could you try the
> approach I describe below? I am almost certain it will allow you to
> reproduce the failure just with opt.
>
> If it does not work, can you provide me with the command line options
> you used to trigger the failure on SPEC?

For the archives:

A test case was committed by Johannes in 261501. Thank you, Johannes.

Best,
Tobias