cvs commit: fptools/ghc/compiler/basicTypes NewDemand.lhs fptools/ghc/compiler/stranal DmdAnal.lhs

[Simon Peyton Jones]

simonpj     2001/07/24 09:42:11 PDT

  Modified files:
    ghc/compiler/basicTypes NewDemand.lhs 
    ghc/compiler/stranal DmdAnal.lhs 
  Log:
  A major demand-analyser fix, which made it say something was
  absent when it wasn't at all.  Here's the comment from the
  Case equation of dmdAnal.
  
  	-- Figure out whether the case binder is used, and use
  	-- that to set the keepity of the demand.  This is utterly essential.
  	-- Consider	f x = case x of y { (a,b) -> k y a }
  	-- If we just take scrut_demand = U(L,A), then we won't pass x to the
  	-- worker, so the worker will rebuild
  	--	x = (a, absent-error)
  	-- and that'll crash.
  
  Revision  Changes    Path
  1.5       +7 -1      fptools/ghc/compiler/basicTypes/NewDemand.lhs
  1.6       +18 -6     fptools/ghc/compiler/stranal/DmdAnal.lhs