[LLVMdev] BasicAA Tests

[Ahmed Bougacha]

On Wed, Feb 4, 2015 at 10:37 AM, Hal Finkel <hfinkel at anl.gov> wrote:
> [+llvmdev]
>
> Hi George,
>
> You're right, these tests are broken, and have been for a long time. As it turns out, at least in terms of the 2003-12-11-ConstExprGEP.ll test, this is related to a case we've been discussing in another thread ("Basic AliasAnalysis: Can GEPs with the same base but different constant indices into a struct alias?"). It seems like, to some extent, we used to have this capability and lost it.
>
> Ahmed, I think you might want to look into this.

Ah, very nice!  I'll have a harder look when I get back to working on
the BasicAA struct improvement.  At a glance, they both seem to be
related, as you say.

In the meantime I'm fine with adding FIXMEs and changing all the tests.

-Ahmed

>  -Hal
>
> ----- Original Message -----
>> From: "George Burgess IV" <george.burgess.iv at gmail.com>
>> To: "Hal Finkel" <hfinkel at anl.gov>
>> Sent: Friday, January 30, 2015 10:54:17 AM
>> Subject: BasicAA Tests
>>
>>
>> Hey,
>>
>>
>> As I was going through the CFLAA tests, I noticed that some of them
>> were passing when they shouldn't have. This was due to that they had
>> ; CHECK-NOT: May:
>>
>>
>> Which doesn't match up with the output of -print-may-alias:
>> MayAlias: %Type %A, %Type2 %B
>>
>>
>> ...So they'd always pass
>>
>>
>> It looks like BasicAA's 2003-12-11-ConstExprGEP.ll and
>> 2003-11-04-SimpleCases.ll have a similar pattern, but changing them
>> to ; CHECK-NOT: MayAlias:, both tests fail.
>>
>>
>> Attached is a diff to fix the tests, and the output of running opt on
>> each of the failing cases
>>
>>
>> George
>
> --
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory