diff options
Diffstat (limited to 'compiler/simplCore/SimplUtils.lhs')
| -rw-r--r-- | compiler/simplCore/SimplUtils.lhs | 41 |
1 files changed, 4 insertions, 37 deletions
diff --git a/compiler/simplCore/SimplUtils.lhs b/compiler/simplCore/SimplUtils.lhs index 4ddd8ca411..48787dceb0 100644 --- a/compiler/simplCore/SimplUtils.lhs +++ b/compiler/simplCore/SimplUtils.lhs @@ -246,42 +246,8 @@ splitInlineCont _ = Nothing \end{code} -\begin{code} -interestingArg :: OutExpr -> Bool - -- An argument is interesting if it has *some* structure - -- We are here trying to avoid unfolding a function that - -- is applied only to variables that have no unfolding - -- (i.e. they are probably lambda bound): f x y z - -- There is little point in inlining f here. -interestingArg (Var v) = hasSomeUnfolding (idUnfolding v) - -- Was: isValueUnfolding (idUnfolding v') - -- But that seems over-pessimistic - || isDataConWorkId v - -- This accounts for an argument like - -- () or [], which is definitely interesting -interestingArg (Type _) = False -interestingArg (App fn (Type _)) = interestingArg fn -interestingArg (Note _ a) = interestingArg a - --- Idea (from Sam B); I'm not sure if it's a good idea, so commented out for now --- interestingArg expr | isUnLiftedType (exprType expr) --- -- Unlifted args are only ever interesting if we know what they are --- = case expr of --- Lit lit -> True --- _ -> False - -interestingArg _ = True - -- Consider let x = 3 in f x - -- The substitution will contain (x -> ContEx 3), and we want to - -- to say that x is an interesting argument. - -- But consider also (\x. f x y) y - -- The substitution will contain (x -> ContEx y), and we want to say - -- that x is not interesting (assuming y has no unfolding) -\end{code} - - -Comment about interestingCallContext -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Note [Interesting call context] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We want to avoid inlining an expression where there can't possibly be any gain, such as in an argument position. Hence, if the continuation is interesting (eg. a case scrutinee, application etc.) then we @@ -316,6 +282,7 @@ default case. \begin{code} interestingCallContext :: SimplCont -> CallCtxt +-- See Note [Interesting call context] interestingCallContext cont = interesting cont where @@ -354,7 +321,7 @@ interestingCallContext cont ------------------- mkArgInfo :: Id -> Int -- Number of value args - -> SimplCont -- Context of the cal + -> SimplCont -- Context of the call -> ArgInfo mkArgInfo fun n_val_args call_cont |