[LLVMdev] [llvm-commits] Bottom-Up Scheduling?

[Hal Finkel]

Andy,

I should have been more clear, the ARM implementation has:
void ARMHazardRecognizer::RecedeCycle() {
  llvm_unreachable("reverse ARM hazard checking unsupported");
}

How does that work?

Thanks again,
Hal

On Tue, 2011-11-29 at 09:47 -0800, Andrew Trick wrote:
> ARM can reuse all the default scoreboard hazard recognizer logic such as recede cycle (naturally since its the primary client). If you can do the same with PPC that's great. 
> 
> Andy
> 
> On Nov 29, 2011, at 8:51 AM, Hal Finkel <hfinkel at anl.gov> wrote:
> 
> >> Thanks! Since I have to change PPCHazardRecognizer for bottom-up support
> >> anyway, is there any reason not to have it derive from
> >> ScoreboardHazardRecognizer at this point? It looks like the custom
> >> bundling logic could be implemented on top of the scoreboard recognizer
> >> (that seems similar to what ARM's recognizer is doing).
> > 
> > Also, how does the ARM hazard recognizer get away with not implementing
> > RecedeCycle?
> > 
> > Thanks again,
> > Hal

-- 
Hal Finkel
Postdoctoral Appointee
Leadership Computing Facility
Argonne National Laboratory