llvm dev - Aug 2007 - [LLVMdev] constructing 'for' statement from LLVM bitcode

Seung,

On 8/25/07, Chris Lattner <sabre at nondot.org>
wrote:
> Ok.  Note that LLVM can represent irreducible loops.  You can handle
> this through code duplication.
> -Chris

If you are willing to invest more effort into a more complicated analysis,
in many cases you can even avoid code duplication. See this paper for
details:

@inproceedings{erosa94taming,
  author    = {Ana M. Erosa and
               Laurie J. Hendren},
  title     = {Taming Control Flow: A Structured Approach to Eliminating
               Goto Statements.},
  booktitle = {ICCL},
  year      = {1994},
  pages     = {229--240},
 }

Cheers,

-- 
        Domagoj Babic

        http://www.domagoj.info/
        http://www.calysto.org/

On 8/29/07, Domagoj Babic <babic.domagoj at gmail.com>
wrote:
> Seung,
>
> On 8/25/07, Chris Lattner <sabre at nondot.org> wrote:
> > Ok.  Note that LLVM can represent irreducible loops.  You can handle
> > this through code duplication.
> > -Chris
>
>
> If you are willing to invest more effort into a more complicated analysis,
> in many cases you can even avoid code duplication. See this paper for
> details:
We implemented this in GCC early on in the days of GIMPLE, and while
theoretically it removes code duplication, in practice it made the
code take significantly more space and run slower. :)
>
> @inproceedings{erosa94taming,
>   author    = {Ana M. Erosa and
>                Laurie J. Hendren},
>   title     = {Taming Control Flow: A Structured Approach to Eliminating
>                Goto Statements.},
>   booktitle = {ICCL},
>   year      = {1994},
>   pages     = {229--240},
>  }
>
> Cheers,
>
> --
>         Domagoj Babic
>
>         http://www.domagoj.info/
>         http://www.calysto.org/
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

Daniel,

On 8/30/07, Daniel Berlin <dberlin at dberlin.org>
wrote:
> On 8/29/07, Domagoj Babic <babic.domagoj at gmail.com> wrote:
> > Seung,
> >
> > On 8/25/07, Chris Lattner <sabre at nondot.org> wrote:
> > > Ok.  Note that LLVM can represent irreducible loops.  You can
handle
> > > this through code duplication.
> > > -Chris
> >
> >
> > If you are willing to invest more effort into a more complicated
analysis,
> > in many cases you can even avoid code duplication. See this paper for
> > details:
>
> We implemented this in GCC early on in the days of GIMPLE, and while
> theoretically it removes code duplication, in practice it made the
> code take significantly more space and run slower. :)
This is good to know, I've never implemented it myself.

I'm a bit surprised that the code took significantly more space.

Cheers,

-- 
        Domagoj Babic

        http://www.domagoj.info/
        http://www.calysto.org/