Does Hoopl handle Bottom internally? By "Bottom" I mean the loop-breaking thing that means "this predecessor does not execute". From the debugging output I added to my code it looks that it in fact does because it doesn't do a join when first analyzing a block with two predecessors. If this is really the case then what is the purpose of defining bottom in DataflowLattice?
Janek ----- Oryginalna wiadomość ----- Od: "Edward Z. Yang" <ezy...@mit.edu> Do: "Jan Stolarek" <jan.stola...@p.lodz.pl> DW: "Simon Peyton-Jones" <simo...@microsoft.com>, "ghc-devs" <ghc-devs@haskell.org> Wysłane: wtorek, 30 lipiec 2013 20:40:53 Temat: Re: Two Hoopl questions What happens when you put a loop in your code? Edward Excerpts from Jan Stolarek's message of Tue Jul 30 08:34:44 -0700 2013: > I'll allow myself to ask my second question again: > > 2) In my algorithm I need to initialize all of the blocks in a graph with > bottom element of a lattice, except for the entry block, which needs some > other initial values. I've written something like this: > > cmmCopyPropagation dflags graph = do > let entry_blk = g_entry graph > g' <- dataflowPassFwd graph [(entry_blk, (Top, Top))] $ > analRewFwd cpLattice cpTransfer cpRewrite > return . fst $ g' > > cpLattice = DataflowLattice "copy propagation" (Bottom, Bottom) cpJoin > > However, it seems that Bottom values passed to cpLattice are ignored - I > could replace second parameter to DataflowLattice with `undefined` and the > code would still run without causing an error. Is there something obviously > wrong in the way I pass initial fact values to dataflowPassFwd, or should I > look for the problem in other parts of my code? > > Janek _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
