llvm dev - Jan 2016 - LLVM - getAnalysisUsage()

Hi,

I am using llvm-3.8 for my project. Following is my getAnalysisUsage() method:

virtual void getAnalysisUsage(AnalysisUsage &AU) const override
{
   AU.setPreservesAll();
   AU.addRequired<X>();
   AU.addRequired<Y>();
   AU.addRequired<Z>();
}

Now, if I call getAnalysis<X>(*F), instead of invoking just the X
pass, all the passes, i.e., X, Y and Z are being invoked. Could anyone
help me in this regard?

Thanks

-- 
Syed

Does analysis X require X, Y, and Z itself?


On Thu, Jan 21, 2016 at 9:05 PM, Syed Rafiul Hussain via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hi,
>
> I am using llvm-3.8 for my project. Following is my getAnalysisUsage()
> method:
>
> virtual void getAnalysisUsage(AnalysisUsage &AU) const override
> {
>    AU.setPreservesAll();
>    AU.addRequired<X>();
>    AU.addRequired<Y>();
>    AU.addRequired<Z>();
> }
>
> Now, if I call getAnalysis<X>(*F), instead of invoking just the X
> pass, all the passes, i.e., X, Y and Z are being invoked. Could anyone
> help me in this regard?
>
> Thanks
>
> --
> Syed
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
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No, X, Y and Z are independent to each other.

On Fri, Jan 22, 2016 at 11:20 AM, Daniel Berlin <dberlin at dberlin.org>
wrote:
> Does analysis X require X, Y, and Z itself?
>
>
> On Thu, Jan 21, 2016 at 9:05 PM, Syed Rafiul Hussain via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>>
>> Hi,
>>
>> I am using llvm-3.8 for my project. Following is my getAnalysisUsage()
>> method:
>>
>> virtual void getAnalysisUsage(AnalysisUsage &AU) const override
>> {
>>    AU.setPreservesAll();
>>    AU.addRequired<X>();
>>    AU.addRequired<Y>();
>>    AU.addRequired<Z>();
>> }
>>
>> Now, if I call getAnalysis<X>(*F), instead of invoking just the X
>> pass, all the passes, i.e., X, Y and Z are being invoked. Could anyone
>> help me in this regard?
>>
>> Thanks
>>
>> --
>> Syed
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>


-- 
Rafi

> On Jan 21, 2016, at 9:05 PM, Syed Rafiul Hussain via llvm-dev <llvm-dev
at lists.llvm.org> wrote:
> 
> Hi,
> 
> I am using llvm-3.8 for my project. Following is my getAnalysisUsage()
method:
> 
> virtual void getAnalysisUsage(AnalysisUsage &AU) const override
> {
>   AU.setPreservesAll();
>   AU.addRequired<X>();
>   AU.addRequired<Y>();
>   AU.addRequired<Z>();
> }
> 
> Now, if I call getAnalysis<X>(*F), instead of invoking just the X
> pass, all the passes, i.e., X, Y and Z are being invoked. Could anyone
> help me in this regard?
This is expected. With the current pass manager, the scheduling is done upfront.
The “addRequired” directive tells the pass manager that before even starting to
run your pass, it needs to schedule X, Y, and Z.
They will run even without the call to  getAnalysis<X>(*F). The new pass
manager (not complete yet but almost) will change that.

When running your pass with opt, you can add —debug-pass=Structure to see what
the scheduling is.

I hope I didn’t misunderstand your question.

— 
Mehdi

I have added -debug-pass=Structure, and found the following:

ModulePass Manager
    X Analysis
      Unnamed pass: implement Pass::getPassName()
    FunctionPass Manager
      Module Verifier
    Bitcode Writer
Pass Arguments:  -x -y -z
  FunctionPass Manager
    X Analysis
    Y Construction
    Z Construction

Even for getAnalysis<Y>(*F) and getAnalysis<Z>(&F), all the
passes X,
Y, Z are executed again. In total there are three places where
getAnalysis() directive has been used for X, Y, Z. However, for each
getAnalysis() call, all three passes are scheduled/executed.




On Fri, Jan 22, 2016 at 12:24 PM, Mehdi Amini <mehdi.amini at apple.com>
wrote:
>
>> On Jan 21, 2016, at 9:05 PM, Syed Rafiul Hussain via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>>
>> Hi,
>>
>> I am using llvm-3.8 for my project. Following is my getAnalysisUsage()
method:
>>
>> virtual void getAnalysisUsage(AnalysisUsage &AU) const override
>> {
>>   AU.setPreservesAll();
>>   AU.addRequired<X>();
>>   AU.addRequired<Y>();
>>   AU.addRequired<Z>();
>> }
>>
>> Now, if I call getAnalysis<X>(*F), instead of invoking just the X
>> pass, all the passes, i.e., X, Y and Z are being invoked. Could anyone
>> help me in this regard?
>
> This is expected. With the current pass manager, the scheduling is done
upfront. The “addRequired” directive tells the pass manager that before even
starting to run your pass, it needs to schedule X, Y, and Z.
> They will run even without the call to  getAnalysis<X>(*F). The new
pass manager (not complete yet but almost) will change that.
>
> When running your pass with opt, you can add —debug-pass=Structure to see
what the scheduling is.
>
> I hope I didn’t misunderstand your question.
>
> —
> Mehdi
>


-- 
Rafi