\begin{code}
callSiteInline :: DynFlags
-> Id -- The Id
- -> Unfolding -- Its unfolding (if active)
+ -> Bool -- True <=> unfolding is active
-> Bool -- True if there are are no arguments at all (incl type args)
-> [ArgSummary] -- One for each value arg; True if it is interesting
-> CallCtxt -- True <=> continuation is interesting
-> Maybe CoreExpr -- Unfolding, if any
-
instance Outputable ArgSummary where
ppr TrivArg = ptext (sLit "TrivArg")
ppr NonTrivArg = ptext (sLit "NonTrivArg")
ppr CaseCtxt = ptext (sLit "CaseCtxt")
ppr ValAppCtxt = ptext (sLit "ValAppCtxt")
-callSiteInline dflags id unfolding lone_variable arg_infos cont_info
- = case unfolding of {
- NoUnfolding -> Nothing ;
- OtherCon _ -> Nothing ;
- DFunUnfolding {} -> Nothing ; -- Never unfold a DFun
- CoreUnfolding { uf_tmpl = unf_template, uf_is_top = is_top,
- uf_is_cheap = is_cheap, uf_arity = uf_arity, uf_guidance = guidance } ->
+callSiteInline dflags id active_unfolding lone_variable arg_infos cont_info
+ = case idUnfolding id of
+ -- idUnfolding checks for loop-breakers, returning NoUnfolding
+ -- Things with an INLINE pragma may have an unfolding *and*
+ -- be a loop breaker (maybe the knot is not yet untied)
+ CoreUnfolding { uf_tmpl = unf_template, uf_is_top = is_top
+ , uf_is_cheap = is_cheap, uf_arity = uf_arity
+ , uf_guidance = guidance }
+ | active_unfolding -> tryUnfolding dflags id lone_variable
+ arg_infos cont_info unf_template is_top
+ is_cheap uf_arity guidance
+ | otherwise -> Nothing
+ NoUnfolding -> Nothing
+ OtherCon {} -> Nothing
+ DFunUnfolding {} -> Nothing -- Never unfold a DFun
+
+tryUnfolding :: DynFlags -> Id -> Bool -> [ArgSummary] -> CallCtxt
+ -> CoreExpr -> Bool -> Bool -> Arity -> UnfoldingGuidance
+ -> Maybe CoreExpr
+tryUnfolding dflags id lone_variable
+ arg_infos cont_info unf_template is_top
+ is_cheap uf_arity guidance
-- uf_arity will typically be equal to (idArity id),
-- but may be less for InlineRules
- let
- n_val_args = length arg_infos
- saturated = n_val_args >= uf_arity
-
- result | yes_or_no = Just unf_template
- | otherwise = Nothing
-
- interesting_args = any nonTriv arg_infos
- -- NB: (any nonTriv arg_infos) looks at the
- -- over-saturated args too which is "wrong";
- -- but if over-saturated we inline anyway.
-
- -- some_benefit is used when the RHS is small enough
- -- and the call has enough (or too many) value
- -- arguments (ie n_val_args >= arity). But there must
- -- be *something* interesting about some argument, or the
- -- result context, to make it worth inlining
- some_benefit
- | not saturated = interesting_args -- Under-saturated
- -- Note [Unsaturated applications]
- | n_val_args > uf_arity = True -- Over-saturated
- | otherwise = interesting_args -- Saturated
- || interesting_saturated_call
-
- interesting_saturated_call
- = case cont_info of
- BoringCtxt -> not is_top && uf_arity > 0 -- Note [Nested functions]
- CaseCtxt -> not (lone_variable && is_cheap) -- Note [Lone variables]
- ArgCtxt {} -> uf_arity > 0 -- Note [Inlining in ArgCtxt]
- ValAppCtxt -> True -- Note [Cast then apply]
-
- (yes_or_no, extra_doc)
- = case guidance of
- UnfNever -> (False, empty)
-
- UnfWhen unsat_ok boring_ok
- -> (enough_args && (boring_ok || some_benefit), empty )
- where -- See Note [INLINE for small functions]
- enough_args = saturated || (unsat_ok && n_val_args > 0)
-
- UnfIfGoodArgs { ug_args = arg_discounts, ug_res = res_discount, ug_size = size }
- -> ( is_cheap && some_benefit && small_enough
- , (text "discounted size =" <+> int discounted_size) )
- where
- discounted_size = size - discount
- small_enough = discounted_size <= opt_UF_UseThreshold
- discount = computeDiscount uf_arity arg_discounts
- res_discount arg_infos cont_info
-
- in
- if (dopt Opt_D_dump_inlinings dflags && dopt Opt_D_verbose_core2core dflags) then
- pprTrace ("Considering inlining: " ++ showSDoc (ppr id))
+ | dopt Opt_D_dump_inlinings dflags && dopt Opt_D_verbose_core2core dflags
+ = pprTrace ("Considering inlining: " ++ showSDoc (ppr id))
(vcat [text "arg infos" <+> ppr arg_infos,
text "uf arity" <+> ppr uf_arity,
text "interesting continuation" <+> ppr cont_info,
text "guidance" <+> ppr guidance,
extra_doc,
text "ANSWER =" <+> if yes_or_no then text "YES" else text "NO"])
- result
- else
- result
- }
+ result
+ | otherwise = result
+
+ where
+ n_val_args = length arg_infos
+ saturated = n_val_args >= uf_arity
+
+ result | yes_or_no = Just unf_template
+ | otherwise = Nothing
+
+ interesting_args = any nonTriv arg_infos
+ -- NB: (any nonTriv arg_infos) looks at the
+ -- over-saturated args too which is "wrong";
+ -- but if over-saturated we inline anyway.
+
+ -- some_benefit is used when the RHS is small enough
+ -- and the call has enough (or too many) value
+ -- arguments (ie n_val_args >= arity). But there must
+ -- be *something* interesting about some argument, or the
+ -- result context, to make it worth inlining
+ some_benefit
+ | not saturated = interesting_args -- Under-saturated
+ -- Note [Unsaturated applications]
+ | n_val_args > uf_arity = True -- Over-saturated
+ | otherwise = interesting_args -- Saturated
+ || interesting_saturated_call
+
+ interesting_saturated_call
+ = case cont_info of
+ BoringCtxt -> not is_top && uf_arity > 0 -- Note [Nested functions]
+ CaseCtxt -> not (lone_variable && is_cheap) -- Note [Lone variables]
+ ArgCtxt {} -> uf_arity > 0 -- Note [Inlining in ArgCtxt]
+ ValAppCtxt -> True -- Note [Cast then apply]
+
+ (yes_or_no, extra_doc)
+ = case guidance of
+ UnfNever -> (False, empty)
+
+ UnfWhen unsat_ok boring_ok
+ -> (enough_args && (boring_ok || some_benefit), empty )
+ where -- See Note [INLINE for small functions]
+ enough_args = saturated || (unsat_ok && n_val_args > 0)
+
+ UnfIfGoodArgs { ug_args = arg_discounts, ug_res = res_discount, ug_size = size }
+ -> ( is_cheap && some_benefit && small_enough
+ , (text "discounted size =" <+> int discounted_size) )
+ where
+ discounted_size = size - discount
+ small_enough = discounted_size <= opt_UF_UseThreshold
+ discount = computeDiscount uf_arity arg_discounts
+ res_discount arg_infos cont_info
\end{code}
Note [RHS of lets]
projects / ghc-hetmet.git / blobdiff