[Soot-list] Any suggestions to find the end of a loop?

[Kelvin Tian]

Hi Eric,

    I've solved my problem through another way, by checking loop header.
Here's the Jimple code of function foo(). Thanks,

    private static void foo()
    {
        int $i0, i1, $i2, $i3, $i4;

        $i0 = <TestLoop: int calls>;
        $i2 = $i0 + 1;
        <TestLoop: int calls> = $i2;
        i1 = 0;

     label0:
        if i1 >= 3 goto label1;

        $i3 = <TestLoop: int loopcnt1>;
        $i4 = $i3 + 1;
        <TestLoop: int loopcnt1> = $i4;
        staticinvoke <TestLoop: void bar()>();
        i1 = i1 + 1;
        goto label0;

     label1:
        staticinvoke <TestLoop: void bar1()>();
        return;
    }



--
Best regards,
Kelvin



On Thu, Jul 30, 2009 at 6:09 PM, Eric Bodden <eric.bodden at mail.mcgill.ca>wrote:

> Hi Kelvin.
>
> This seems odd to me. Can you post the whole Jimple body for this
> method, please?
>
> Eric
>
> 2009/7/29 Kelvin Tian <kevinn.tian at gmail.com>:
> > Dear Eric,
> >
> >     Thanks for the reply.  I can find the end of loop now except one
> > scenario, which has a function call below the loop.  In the example code
> > below,  I found the loop header and its successors and post-dominator as
> > follows.
> >
> >     private static void foo() {
> >         calls++;
> >         for (int i = 0; i < 3; i++)
> >            {
> >             loopcnt1++;
> >             bar();
> >         }
> >
> >         bar1();
> >     }
> >
> > loop header:   if i1 >= 3 goto staticinvoke <TestLoop: void bar1()>()
> > loop header's post-dominator:   [return, if i1 >= 3 goto staticinvoke
> > <TestLoop: void bar1()>()]
> > loop header's successor:    [$i3 = <TestLoop: int loopcnt1>, staticinvoke
> > <TestLoop: void bar1()>()]
> >
> > So I see in Soot, the loop header connects two statements together,
> without
> > labels . The loop header's post-dominators include "return" and itself,
> > while don't include the statement "bar1()" after the loop because the
> loop
> > header already contains calling to "bar1()".  But the loop header's
> > successors include the original statement "bar1()" after the loop,  so in
> > this case I can't find the end of the loop.  So it seems loop header has
> two
> > different representations when getting its post-dominator and its
> > successors.  Is this conflict an original design or a possible bug? Are
> > there any suggestions? Thanks again for your help!
> >
> >
> > --
> > Best regards,
> > Kelvin
> >
> >
> >
> > On Mon, Jul 27, 2009 at 3:45 PM, Eric Bodden <eric.bodden at mail.mcgill.ca
> >
> > wrote:
> >>
> >> Hi Kelvin.
> >>
> >> I wound have done it the same way - sounds reasonable to me.
> >>
> >> Eric
> >>
> >> 2009/7/27 Kelvin Tian <kevinn.tian at gmail.com>:
> >> > I need to identify the end of a loop and to print out some profiling
> >> > info
> >> > after a loop's execution.  One way I've got to identify the end of a
> >> > loop is
> >> > to find the loop head, and iterate through its successors, as the
> >> > statements
> >> > in loop body can't be the post-dominator of the loop head, so when I
> >> > meet
> >> > with a statement which is a post dominator of the loop head,  then the
> >> > end
> >> > of a loop is found.   Is this way applicable for Soot to implement or
> >> > are
> >> > there any better suggestions?  Thanks for any suggestions!
> >> >
> >> >
> >> > --
> >> > Best regards,
> >> > Kelvin
> >> >
> >> >
> >> > _______________________________________________
> >> > Soot-list mailing list
> >> > Soot-list at sable.mcgill.ca
> >> > http://mailman.cs.mcgill.ca/mailman/listinfo/soot-list
> >> >
> >> >
> >>
> >>
> >>
> >> --
> >> Eric Bodden
> >> Software Technology Group
> >> Technical University Darmstadt, Germany
> >
> >
>
>
>
> --
> Eric Bodden
> Software Technology Group
> Technical University Darmstadt, Germany
>
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