Two Hoopl questions
jan.stolarek at p.lodz.pl
Tue Jul 30 17:34:44 CEST 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?
More information about the ghc-devs