-- Inlining,
preInlineUnconditionally, postInlineUnconditionally,
- activeInline, activeRule, inlineMode,
+ activeInline, activeRule,
-- The continuation type
SimplCont(..), DupFlag(..), ArgInfo(..),
contIsDupable, contResultType, contIsTrivial, contArgs, dropArgs,
- countValArgs, countArgs, splitInlineCont,
+ countValArgs, countArgs,
mkBoringStop, mkLazyArgStop, contIsRhsOrArg,
- interestingCallContext, interestingArgContext,
+ interestingCallContext,
interestingArg, mkArgInfo,
dropArgs 0 cont = cont
dropArgs n (ApplyTo _ _ _ cont) = dropArgs (n-1) cont
dropArgs n other = pprPanic "dropArgs" (ppr n <+> ppr other)
-
---------------------
-splitInlineCont :: SimplCont -> Maybe (SimplCont, SimplCont)
--- Returns Nothing if the continuation should dissolve an InlineMe Note
--- Return Just (c1,c2) otherwise,
--- where c1 is the continuation to put inside the InlineMe
--- and c2 outside
-
--- Example: (__inline_me__ (/\a. e)) ty
--- Here we want to do the beta-redex without dissolving the InlineMe
--- See test simpl017 (and Trac #1627) for a good example of why this is important
-
-splitInlineCont (ApplyTo dup (Type ty) se c)
- | Just (c1, c2) <- splitInlineCont c = Just (ApplyTo dup (Type ty) se c1, c2)
-splitInlineCont cont@(Stop {}) = Just (mkBoringStop, cont)
-splitInlineCont cont@(StrictBind {}) = Just (mkBoringStop, cont)
-splitInlineCont _ = Nothing
- -- NB: we dissolve an InlineMe in any strict context,
- -- not just function aplication.
- -- E.g. foldr k z (__inline_me (case x of p -> build ...))
- -- Here we want to get rid of the __inline_me__ so we
- -- can float the case, and see foldr/build
- --
- -- However *not* in a strict RHS, else we get
- -- let f = __inline_me__ (\x. e) in ...f...
- -- Now if f is guaranteed to be called, hence a strict binding
- -- we don't thereby want to dissolve the __inline_me__; for
- -- example, 'f' might be a wrapper, so we'd inline the worker
\end{code}
-------------------
mkArgInfo :: Id
+ -> [CoreRule] -- Rules for function
-> Int -- Number of value args
-> SimplCont -- Context of the call
-> ArgInfo
-mkArgInfo fun n_val_args call_cont
+mkArgInfo fun rules n_val_args call_cont
| n_val_args < idArity fun -- Note [Unsaturated functions]
= ArgInfo { ai_rules = False
, ai_strs = vanilla_stricts
, ai_discs = vanilla_discounts }
| otherwise
- = ArgInfo { ai_rules = interestingArgContext fun call_cont
+ = ArgInfo { ai_rules = interestingArgContext rules call_cont
, ai_strs = add_type_str (idType fun) arg_stricts
, ai_discs = arg_discounts }
where
vanilla_discounts, arg_discounts :: [Int]
vanilla_discounts = repeat 0
arg_discounts = case idUnfolding fun of
- CoreUnfolding _ _ _ _ _ (UnfoldIfGoodArgs _ discounts _ _)
+ CoreUnfolding {uf_guidance = UnfoldIfGoodArgs {ug_args = discounts}}
-> discounts ++ vanilla_discounts
_ -> vanilla_discounts
on its first argument -- it must be saturated for these to kick in
-}
-interestingArgContext :: Id -> SimplCont -> Bool
+interestingArgContext :: [CoreRule] -> SimplCont -> Bool
-- If the argument has form (f x y), where x,y are boring,
-- and f is marked INLINE, then we don't want to inline f.
-- But if the context of the argument is
-- where h has rules, then we do want to inline f; hence the
-- call_cont argument to interestingArgContext
--
--- The interesting_arg_ctxt flag makes this happen; if it's
+-- The ai-rules flag makes this happen; if it's
-- set, the inliner gets just enough keener to inline f
-- regardless of how boring f's arguments are, if it's marked INLINE
--
-- The alternative would be to *always* inline an INLINE function,
-- regardless of how boring its context is; but that seems overkill
-- For example, it'd mean that wrapper functions were always inlined
-interestingArgContext fn call_cont
- = idHasRules fn || go call_cont
+interestingArgContext rules call_cont
+ = notNull rules || enclosing_fn_has_rules
where
+ enclosing_fn_has_rules = go call_cont
+
go (Select {}) = False
go (ApplyTo {}) = False
go (StrictArg _ cci _ _) = interesting cci
INLINE pragmas
~~~~~~~~~~~~~~
-SimplGently is also used as the mode to simplify inside an InlineMe note.
-
-\begin{code}
-inlineMode :: SimplifierMode
-inlineMode = SimplGently
-\end{code}
-
+We don't simplify inside InlineRules (which come from INLINE pragmas).
It really is important to switch off inlinings inside such
expressions. Consider the following example
where
phase = getMode env
active = case phase of
- SimplGently -> isAlwaysActive act
+ SimplGently -> isEarlyActive act
SimplPhase n _ -> isActive n act
act = idInlineActivation bndr
\begin{code}
postInlineUnconditionally
:: SimplEnv -> TopLevelFlag
- -> InId -- The binder (an OutId would be fine too)
+ -> OutId -- The binder (an InId would be fine too)
-> OccInfo -- From the InId
-> OutExpr
-> Unfolding
| isLoopBreaker occ_info = False -- If it's a loop-breaker of any kind, don't inline
-- because it might be referred to "earlier"
| isExportedId bndr = False
+ | isInlineRule unfolding = False -- Note [InlineRule and postInlineUnconditionally]
| exprIsTrivial rhs = True
| otherwise
= case occ_info of
SimplPhase n _ -> Just (isActive n)
\end{code}
+Note [InlineRule and postInlineUnconditionally]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Do not do postInlineUnconditionally if the Id has an InlineRule, otherwise
+we lose the unfolding. Example
+
+ -- f has InlineRule with rhs (e |> co)
+ -- where 'e' is big
+ f = e |> co
+
+Then there's a danger we'll optimise to
+
+ f' = e
+ f = f' |> co
+
+and now postInlineUnconditionally, losing the InlineRule on f. Now f'
+won't inline because 'e' is too big.
+
%************************************************************************
%* *
mkLam _b [] body
= return body
-mkLam _env bndrs body
+mkLam env bndrs body
= do { dflags <- getDOptsSmpl
; mkLam' dflags bndrs body }
where
; return etad_lam }
| dopt Opt_DoLambdaEtaExpansion dflags,
- any isRuntimeVar bndrs
+ not (inGentleMode env), -- In gentle mode don't eta-expansion
+ any isRuntimeVar bndrs -- because it can clutter up the code
+ -- with casts etc that may not be removed
= do { let body' = tryEtaExpansion dflags body
; return (mkLams bndrs body') }
projects / ghc-hetmet.git / blobdiff