[llvm] r233930 - [LoopAccesses] Handle case when no memchecks are needed after partitioning

[David Blaikie]

On Fri, May 15, 2015 at 8:15 AM, Adam Nemet <anemet at apple.com> wrote:

>
> On Apr 2, 2015, at 8:16 PM, Adam Nemet <anemet at apple.com> wrote:
>
>
> On Apr 2, 2015, at 11:15 AM, David Blaikie <dblaikie at gmail.com> wrote:
>
>
>
> On Thu, Apr 2, 2015 at 11:09 AM, Adam Nemet <anemet at apple.com> wrote:
>
>>
>> On Apr 2, 2015, at 11:05 AM, David Blaikie <dblaikie at gmail.com> wrote:
>>
>> Test case? Or is this just a perf improvement?
>>
>>
>> No it’s a bug fix because without this check we will use the null
>> MemoryRuntimeCheck later.
>>
>> There should be a way to come up with a testcase even without Loop
>> Distribution but it should be much easier with Loop Distribution.  Let me
>> add a testcase for this as part of the LDist patch.  OK?
>>
>
> Sure - follow up here with the revision the test is committed in?
>
>
> Sounds good, I have this thread marked already.
>
>
> The testcase that originally triggered this is now committed as
> test/Transforms/LoopDistribute/crash-in-memcheck-generation.ll.
>

Helpful to have the commit revision as well, for posterity. Looks like it's
r237358

Thanks!


>
> Adam
>
>
>
>
>>
>> Adam
>>
>> On Thu, Apr 2, 2015 at 10:51 AM, Adam Nemet <anemet at apple.com> wrote:
>>
>>> Author: anemet
>>> Date: Thu Apr  2 12:51:57 2015
>>> New Revision: 233930
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=233930&view=rev
>>> Log:
>>> [LoopAccesses] Handle case when no memchecks are needed after
>>> partitioning
>>>
>>> Modified:
>>>     llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
>>>
>>> Modified: llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp?rev=233930&r1=233929&r2=233930&view=diff
>>>
>>> ==============================================================================
>>> --- llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp (original)
>>> +++ llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp Thu Apr  2 12:51:57
>>> 2015
>>> @@ -1211,9 +1211,8 @@ static Instruction *getFirstInst(Instruc
>>>
>>>  std::pair<Instruction *, Instruction *> LoopAccessInfo::addRuntimeCheck(
>>>      Instruction *Loc, const SmallVectorImpl<int> *PtrPartition) const {
>>> -  Instruction *tnullptr = nullptr;
>>>    if (!PtrRtCheck.Need)
>>> -    return std::pair<Instruction *, Instruction *>(tnullptr, tnullptr);
>>> +    return std::make_pair(nullptr, nullptr);
>>>
>>>    unsigned NumPointers = PtrRtCheck.Pointers.size();
>>>    SmallVector<TrackingVH<Value> , 2> Starts;
>>> @@ -1284,6 +1283,9 @@ std::pair<Instruction *, Instruction *>
>>>      }
>>>    }
>>>
>>> +  if (!MemoryRuntimeCheck)
>>> +    return std::make_pair(nullptr, nullptr);
>>> +
>>>    // We have to do this trickery because the IRBuilder might fold the
>>> check to a
>>>    // constant expression in which case there is no Instruction anchored
>>> in a
>>>    // the block.
>>>
>>>
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>
>>
>>
>>
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