[LLVMdev] The problem of densemap and loop

[Hanbing Li]

Hi, 

I tried to solve the problem by myself. And when I even got the densemap with 6 items, I still got 0 in another ModulePass by using the loopinfo derived in the new ModulePass. So if this means that when I use a loop in LoopInfo in a Function/ModulePass, I can't get the same loop object in another ModulePass. In other words, the loop objects in two ModulePasses are always different? 
Does anyone know something about it? 

Thank you 

Sincerely, 

Hanbing 

----- Mail original -----

> De: "Hanbing Li" <hanbing.li at inria.fr>
> À: "John Criswell" <jtcriswel at gmail.com>
> Cc: llvmdev at cs.uiuc.edu
> Envoyé: Vendredi 29 Août 2014 10:47:07
> Objet: Re: [LLVMdev] The problem of densemap and loop

> Dear John,

> First thing, the 3 loops in Densemap are all " Loop at depth 1 containing:
> %1<header><exiting>,%3,%5<latch> " in the 3 functions.

> The dense map is in a ImmutablePass. I got it in FunctionPass and tried
> insert the information in this FunctionPass. So to turn the FunctionPass to
> ModulePass may be a better idea?

> Another interesting thing: if just before the insertion, I used "L ->
> print(errs());" to print the Loop, there were 6 items in ls. BUT when I
> tried to read it in a ModulePass, I can't get the correct result.
> "

> for (Module::iterator FI = M.begin(), E = M.end(); FI != E; ) {
> F = FI++;

> if (!F->hasName() && !F->isDeclaration()){}
> else{

> LoopInfo *LI = &getAnalysis<LoopInfo>(*F);
> WCETInfo *WI = &getAnalysis<WCETInfo>(); //WI is the ImmutablePass which
> contains the dense map

> for(LoopInfo::iterator i=LI->begin(); i!=LI->end(); ++i) {
> Loop *L = *i;

> int lb=0;
> lb=WI->outls(L); // the method: return ls.find(L)->second;

> }

> }

> } "

> Thank you

> Sincerely,

> Hanbing

> ----- Mail original -----

> > De: "John Criswell" <jtcriswel at gmail.com>
> 
> > À: "Hanbing Li" <hanbing.li at inria.fr>, llvmdev at cs.uiuc.edu
> 
> > Envoyé: Jeudi 28 Août 2014 18:59:52
> 
> > Objet: Re: [LLVMdev] The problem of densemap and loop
> 

> > Dear Hanbing,
> 

> > You haven't provided enough information to help diagnose the problem. It
> > would help if you specified which 3 loops actually end up in the DenseMap.
> 

> > One thing to check for is if your code is in a FunctionPass. A FunctionPass
> > computes its results anew each time it is run on a function, and so it's
> > possible that this is the cause of the problem. Similarly, the Loop objects
> > for each function might be deleted and re-allocated for new Loop objects
> > every time you run the LoopAnalysis on a new function. That would make it
> > look like you only have three elements when, in fact, you've added six
> > elements but three were deallocated.
> 

> > Alternatively, you might have some something silly like making ls a local
> > variable, so it gets destroyed each time you enter the function/method in
> > which it appears.
> 

> > However, these are just guesses. I'm not certain it can be diagnosed even
> > if
> > you do provide more information.
> 

> > Regards,
> 

> > John Criswell
> 

> > On 8/28/14, 12:49 PM, Hanbing Li wrote:
> 

> > > Hello, everyone,
> > 
> 

> > > I created a dense map like this: DenseMap<Loop *, int> ls;
> > 
> 
> > > And I have a module which contains 3 functions:
> > 
> 
> > > function F and it has a loop which is " Loop at depth 1 containing:
> > > %1<header><exiting>,%3,%5<latch> "
> > 
> 
> > > function G and it has two loops which are "
> > 
> 

> > > Loop at depth 1 containing: %8<header><exiting>,%10,%14<latch>
> > 
> 

> > > Loop at depth 1 containing: %1<header><exiting>,%3,%5<latch> "
> > 
> 
> > > function main and it has 3 loops which are "
> > 
> 

> > > Loop at depth 1 containing: %17<header><exiting>,%19,%23<latch>
> > 
> 

> > > Loop at depth 1 containing: %8<header><exiting>,%10,%14<latch
> > 
> 

> > > Loop at depth 1 containing: %1<header><exiting>,%3,%5<latch> "
> > 
> 
> > > Then I tried to insert these loops into ls and the expected result is
> > > that
> > > there are 6 items in ls after the insertion.
> > 
> 
> > > But I got only 3.
> > 
> 

> > > So my question is why this happened?
> > 
> 
> > > The dense map uses the name of the loop to check if the element is in it?
> > 
> 
> > > Is there anything wrong during my code?
> > 
> 

> > > Looking forward to your answer.
> > 
> 

> > > Thank you
> > 
> 

> > > Sincerely,
> > 
> 

> > > Hanbing
> > 
> 

> > > _______________________________________________
> > 
> 
> > > LLVM Developers mailing list LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
> > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> > 
> 

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