[LLVMdev] Fwd: Improper Function::iterator increment

[Pranav Kant]

Input to this pass is the bitcode format of simple code below :

int sum_single_loop (int a){
   int su = 0, i;
   for (i=0;i<a;i++)
      su = su + i;
   return su;
}


On Mon, Feb 9, 2015 at 2:32 AM, David Blaikie <dblaikie at gmail.com> wrote:

>
>
> On Sun, Feb 8, 2015 at 11:23 AM, Pranav Kant <pranav913 at gmail.com> wrote:
>
>> So, you mean to say that the above implementation is correct and should
>> work fine.
>>
>
> So far as I can see - but I could be missing something.
>
>
>> I initially thought that the above way is not the correct way anymore
>> since 3.5.0 might have changed few things.
>>
>> Anyways here is my dirty code I have written for my research project that
>> I took the above snippet from :
>>
>> https://github.com/pranavk/spatial-computing/blob/master/waves.cpp#L105
>>
>
> Someone (not necessarily me) will presumably need the
> input/command/arguments/whatever required to trigger the infinite loop in
> this code that you're seeing, as well as the code there.
>
>
>>
>>
>>
>> On Sun, Feb 8, 2015 at 10:25 PM, David Blaikie <dblaikie at gmail.com>
>> wrote:
>>
>>> This may be difficult yo reproduce or debug without a more complete
>>> (though preferably minimal) test case.
>>> On Feb 8, 2015 8:31 AM, "Pranav Kant" <pranav913 at gmail.com> wrote:
>>>
>>>> void Wave::init (const Function &F){
>>>>     Function::const_iterator ie = F.end();
>>>>     outs() << ie << "\n\n";
>>>>     for (Function::const_iterator I = F.begin(), IE = F.end(); I != IE;
>>>> I++, K++){
>>>>        outs() << I << "\n";
>>>>        // some manipulation with I
>>>>     }
>>>> }
>>>>
>>>> I used the above shown function in my pass in LLVM 3.4.2 and it used to
>>>> work fine but when I am compiling this pass with 3.5.0, this is a never
>>>> ending loop. Can someone please suggest me what can be wrong here ?
>>>>
>>>> Upon some debugging, I found out that const_iterator I never becomes
>>>> equal to IE, rather it goes past IE when incremented and hence loop never
>>>> ends.
>>>>
>>>> Following is the output upon executing above code.
>>>>
>>>> 0x2e08248 <- address of ie
>>>> 0x2e16630 <- address of I initially
>>>> 0x2e08250 <- incremented I
>>>> 0x2e165e0
>>>> 0x2e16630
>>>> 0x2e08250
>>>> 0x2e165e0
>>>> 0x2e16630
>>>> 0x2e08250
>>>>
>>>>
>>>>
>>>> --
>>>> Regards,
>>>> Pranav Kant,
>>>> Department of Computer Science
>>>> National Institute of Technology Hamirpur
>>>> http://pricked.in/
>>>>
>>>>
>>>>
>>>> --
>>>> Regards,
>>>> Pranav Kant,
>>>> Department of Computer Science
>>>> National Institute of Technology Hamirpur
>>>> http://pricked.in/
>>>>
>>>> _______________________________________________
>>>> LLVM Developers mailing list
>>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>>>
>>>>
>>
>>
>> --
>> Regards,
>> Pranav Kant,
>> Department of Computer Science
>> National Institute of Technology Hamirpur
>> http://pricked.in/
>>
>
>


-- 
Regards,
Pranav Kant,
Department of Computer Science
National Institute of Technology Hamirpur
http://pricked.in/
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