[LLVMdev] BasicAA Tests

Hal Finkel hfinkel at anl.gov
Wed Feb 4 10:37:14 PST 2015


[+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.

 -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



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