diff options
| -rw-r--r-- | compiler/basicTypes/Demand.lhs | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/compiler/basicTypes/Demand.lhs b/compiler/basicTypes/Demand.lhs index af28473517..936fdfc5d0 100644 --- a/compiler/basicTypes/Demand.lhs +++ b/compiler/basicTypes/Demand.lhs @@ -621,18 +621,18 @@ resTypeArgDmd _ = top \end{code} %************************************************************************ -%* * +%* * Whether a demand justifies a w/w split -%* * +%* * %************************************************************************ \begin{code} worthSplittingFun :: [Demand] -> DmdResult -> Bool - -- True <=> the wrapper would not be an identity function + -- True <=> the wrapper would not be an identity function worthSplittingFun ds res = any worth_it ds || returnsCPR res - -- worthSplitting returns False for an empty list of demands, - -- and hence do_strict_ww is False if arity is zero and there is no CPR + -- worthSplitting returns False for an empty list of demands, + -- and hence do_strict_ww is False if arity is zero and there is no CPR where -- See Note [Worker-wrapper for bottoming functions] worth_it (JD {strd=HyperStr, absd=a}) = isUsed a -- A Hyper-strict argument, safe to do W/W @@ -641,19 +641,19 @@ worthSplittingFun ds res worth_it (JD {strd=SProd _}) = True -- Product arg to evaluate worth_it (JD {strd=Str, absd=UProd _}) = True -- Strictly used product arg worth_it (JD {strd=Str, absd=UHead}) = True - worth_it _ = False + worth_it _ = False -worthSplittingThunk :: Demand -- Demand on the thunk - -> DmdResult -- CPR info for the thunk - -> Bool +worthSplittingThunk :: Demand -- Demand on the thunk + -> DmdResult -- CPR info for the thunk + -> Bool worthSplittingThunk dmd res = worth_it dmd || returnsCPR res where - -- Split if the thing is unpacked + -- Split if the thing is unpacked worth_it (JD {strd=SProd _, absd=a}) = someCompUsed a worth_it (JD {strd=Str, absd=UProd _}) = True -- second component points out that at least some of - worth_it _ = False + worth_it _ = False \end{code} Note [Worthy functions for Worker-Wrapper split] @@ -710,10 +710,10 @@ We used not to split if the result is bottom. [Justification: there's no efficiency to be gained.] But it's sometimes bad not to make a wrapper. Consider - fw = \x# -> let x = I# x# in case e of - p1 -> error_fn x - p2 -> error_fn x - p3 -> the real stuff + fw = \x# -> let x = I# x# in case e of + p1 -> error_fn x + p2 -> error_fn x + p3 -> the real stuff The re-boxing code won't go away unless error_fn gets a wrapper too. [We don't do reboxing now, but in general it's better to pass an unboxed thing to f, and have it reboxed in the error cases....] |