Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : supercompiler
http://hackage.haskell.org/trac/ghc/changeset/89be6152f0f9035ec98f62ec00c70159bc323091 >--------------------------------------------------------------- commit 89be6152f0f9035ec98f62ec00c70159bc323091 Author: Max Bolingbroke <batterseapo...@hotmail.com> Date: Thu Mar 1 13:55:13 2012 +0000 Only abstract over RealWorld# conditionally >--------------------------------------------------------------- .../supercompile/Supercompile/Drive/Process.hs | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) diff --git a/compiler/supercompile/Supercompile/Drive/Process.hs b/compiler/supercompile/Supercompile/Drive/Process.hs index 9811617..f7c7668 100644 --- a/compiler/supercompile/Supercompile/Drive/Process.hs +++ b/compiler/supercompile/Supercompile/Drive/Process.hs @@ -793,16 +793,19 @@ applyAbsVars x xs = snd (foldl go (unitVarSet x, var x) xs) -- NB: make sure we zap the "fragile" info because the FVs of the unfolding are -- not necessarily in scope. --- NB: we abstract over RealWorld# as well (cf WwLib). Two reasons: +-- NB: if there are no arguments, we abstract over RealWorld# as well (cf WwLib). Two reasons: -- 1. If the h-function is unlifted, this delays its evaluation (so its effects, if any, do not happen too early). -- This is also necessary since h-functions will be bound in one letrec after supercompilation is complete. --- 2. This expresses to GHC that we don't necessarily want the work in h-functions to be shared. +-- 2. In other cases, this expresses to GHC that we don't necessarily want the work in h-functions to be shared. stateAbsVars :: Maybe FreeVars -> State -> ([AbsVar], Type) -stateAbsVars mb_lvs state = (abstracted, realWorldStatePrimTy `mkFunTy` (vs_list `mkPiTypes` state_ty)) +stateAbsVars mb_lvs state + | any (isId . absVarVar) abstracted + = (abstracted, ty) + | otherwise + = (AbsVar { absVarDead = True, absVarVar = voidArgId } : abstracted, realWorldStatePrimTy `mkFunTy` ty) where vs_list = sortQuantVars (varSetElems (stateLambdaBounders state)) - state_ty = stateType state - abstracted = AbsVar { absVarDead = True, absVarVar = voidArgId } : - map (\v -> AbsVar { absVarDead = maybe False (not . (v `elemVarSet`)) mb_lvs, absVarVar = v }) vs_list + ty = vs_list `mkPiTypes` stateType state + abstracted = map (\v -> AbsVar { absVarDead = maybe False (not . (v `elemVarSet`)) mb_lvs, absVarVar = v }) vs_list -- | Free variables that are allowed to be in the output term even though they weren't in the input (in addition to h-function names) _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
