[LLVMdev] Custom Static Scheduling

[Benjamin Mueller]

Pekka Jääskeläinen <pekka.jaaskelainen <at> tut.fi> writes:

> 
> Hi,
> 
> On 06/18/2011 06:26 AM, Benjamin Müller wrote:
> > i created a Function Pass to retrieve the Control/Data Flow Graph from
> > a simple program,
> > now i would like to statically schedule the Instructions. Is this
> > possible by starting to modify the SelectionDAG Files ?
> > Or can i even build a "standalone" custom scheduler?
> > Thank you very much for any tipps.
> 
> You might be interested to look at our recent scheduler generalization
> project in TCE [1].
> 
> In our case we convert from LLVM MachineInstructions to the IR of our
> custom scheduler (CFG+DDG) which is then converted back to fresh
> MachineBasicBlocks/MachineInstructions for assembly generation in
> the LLVM side. The first (non-TTA) target we are experimenting with
> is the Cell SPU.
> 
> Eventually we hope to see the LLVM code generation framework improved
> to the point that less-and-less custom TCE library code (and our ADF) is
> needed for static scheduling. However, the TCE scheduler generalization
> project has started quite recently so there's plenty of work to do before
> the compiler chain that includes the TCE scheduler can be considered
> production quality.
> 
> [1] http://tce.cs.tut.fi/cgi-bin/moin.cgi/SchedulerGeneralization
> 
> Best regards,


Hello Pekka,
thank you for your reply, that is an interesting project you have there - but
this is a little bit too much overhead for what i need to do.
Basically i need just to write a static scheduler for a simple program using
SDNodes/SUnits/SDep and their Succs and Preds. I am still trying to figure out
how they work together.

All the Best
Ben