couldBeSmallEnoughToInline,
certainlyWillInline, smallEnoughToInline,
- callSiteInline, CallContInfo(..)
+ callSiteInline, CallCtxt(..)
) where
-> Id -- The Id
-> Bool -- True if there are are no arguments at all (incl type args)
-> [Bool] -- One for each value arg; True if it is interesting
- -> CallContInfo -- True <=> continuation is interesting
+ -> CallCtxt -- True <=> continuation is interesting
-> Maybe CoreExpr -- Unfolding, if any
-data CallContInfo = BoringCont
- | InterestingCont -- Somewhat interesting
- | CaseCont -- Very interesting; the argument of a case
- -- that decomposes its scrutinee
+data CallCtxt = BoringCtxt
-instance Outputable CallContInfo where
- ppr BoringCont = ptext SLIT("BoringCont")
- ppr InterestingCont = ptext SLIT("InterestingCont")
- ppr CaseCont = ptext SLIT("CaseCont")
+ | ArgCtxt Bool -- We're somewhere in the RHS of function with rules
+ -- => be keener to inline
+ Int -- We *are* the argument of a function with this arg discount
+ -- => be keener to inline
+ -- INVARIANT: ArgCtxt False 0 ==> BoringCtxt
+
+ | CaseCtxt -- We're the scrutinee of a case
+ -- that decomposes its scrutinee
+
+instance Outputable CallCtxt where
+ ppr BoringCtxt = ptext SLIT("BoringCtxt")
+ ppr (ArgCtxt _ _) = ptext SLIT("ArgCtxt")
+ ppr CaseCtxt = ptext SLIT("CaseCtxt")
callSiteInline dflags active_inline id lone_variable arg_infos cont_info
= case idUnfolding id of {
interesting_saturated_call
= case cont_info of
- BoringCont -> not is_top && n_vals_wanted > 0 -- Note [Nested functions]
- CaseCont -> not lone_variable || not is_value -- Note [Lone variables]
- InterestingCont -> n_vals_wanted > 0
+ BoringCtxt -> not is_top && n_vals_wanted > 0 -- Note [Nested functions]
+ CaseCtxt -> not lone_variable || not is_value -- Note [Lone variables]
+ ArgCtxt {} -> True
+ -- Was: n_vals_wanted > 0; but see test eyeball/inline1.hs
small_enough = (size - discount) <= opt_UF_UseThreshold
discount = computeDiscount n_vals_wanted arg_discounts
res_discount' arg_infos
res_discount' = case cont_info of
- BoringCont -> 0
- CaseCont -> res_discount
- InterestingCont -> 4 `min` res_discount
+ BoringCtxt -> 0
+ CaseCtxt -> res_discount
+ ArgCtxt _ _ -> 4 `min` res_discount
-- res_discount can be very large when a function returns
-- construtors; but we only want to invoke that large discount
-- when there's a case continuation.
activeInline, activeRule, inlineMode,
-- The continuation type
- SimplCont(..), DupFlag(..), LetRhsFlag(..),
+ SimplCont(..), DupFlag(..), ArgInfo(..),
contIsDupable, contResultType, contIsTrivial, contArgs, dropArgs,
countValArgs, countArgs, splitInlineCont,
mkBoringStop, mkLazyArgStop, mkRhsStop, contIsRhsOrArg,
data SimplCont
= Stop -- An empty context, or hole, []
OutType -- Type of the result
- LetRhsFlag
- Bool -- True <=> There is something interesting about
+ CallCtxt -- True <=> There is something interesting about
-- the context, and hence the inliner
-- should be a bit keener (see interestingCallContext)
-- Specifically:
| StrictArg -- e C
OutExpr OutType -- e and its type
- (Bool,[Bool]) -- Whether the function at the head of e has rules,
- SimplCont -- plus strictness flags for further args
-
-data LetRhsFlag = AnArg -- It's just an argument not a let RHS
- | AnRhs -- It's the RHS of a let (so please float lets out of big lambdas)
-
-instance Outputable LetRhsFlag where
- ppr AnArg = ptext SLIT("arg")
- ppr AnRhs = ptext SLIT("rhs")
+ CallCtxt -- Whether *this* argument position is interesting
+ ArgInfo -- Whether the function at the head of e has rules, etc
+ SimplCont -- plus strictness flags for *further* args
+
+data ArgInfo
+ = ArgInfo {
+ ai_rules :: Bool, -- Function has rules (recursively)
+ -- => be keener to inline in all args
+ ai_strs :: [Bool], -- Strictness of arguments
+ -- Usually infinite, but if it is finite it guarantees
+ -- that the function diverges after being given
+ -- that number of args
+ ai_discs :: [Int] -- Discounts for arguments; non-zero => be keener to inline
+ -- Always infinite
+ }
instance Outputable SimplCont where
- ppr (Stop ty is_rhs _) = ptext SLIT("Stop") <> brackets (ppr is_rhs) <+> ppr ty
+ ppr (Stop ty _) = ptext SLIT("Stop") <+> ppr ty
ppr (ApplyTo dup arg se cont) = ((ptext SLIT("ApplyTo") <+> ppr dup <+> pprParendExpr arg)
{- $$ nest 2 (pprSimplEnv se) -}) $$ ppr cont
ppr (StrictBind b _ _ _ cont) = (ptext SLIT("StrictBind") <+> ppr b) $$ ppr cont
- ppr (StrictArg f _ _ cont) = (ptext SLIT("StrictArg") <+> ppr f) $$ ppr cont
+ ppr (StrictArg f _ _ _ cont) = (ptext SLIT("StrictArg") <+> ppr f) $$ ppr cont
ppr (Select dup bndr alts se cont) = (ptext SLIT("Select") <+> ppr dup <+> ppr bndr) $$
(nest 4 (ppr alts)) $$ ppr cont
ppr (CoerceIt co cont) = (ptext SLIT("CoerceIt") <+> ppr co) $$ ppr cont
-------------------
mkBoringStop :: OutType -> SimplCont
-mkBoringStop ty = Stop ty AnArg False
+mkBoringStop ty = Stop ty BoringCtxt
-mkLazyArgStop :: OutType -> Bool -> SimplCont
-mkLazyArgStop ty has_rules = Stop ty AnArg has_rules
+mkLazyArgStop :: OutType -> CallCtxt -> SimplCont
+mkLazyArgStop ty cci = Stop ty cci
mkRhsStop :: OutType -> SimplCont
-mkRhsStop ty = Stop ty AnRhs False
+mkRhsStop ty = Stop ty BoringCtxt
-------------------
contIsRhsOrArg (Stop {}) = True
-------------------
contResultType :: SimplCont -> OutType
-contResultType (Stop to_ty _ _) = to_ty
-contResultType (StrictArg _ _ _ cont) = contResultType cont
+contResultType (Stop to_ty _) = to_ty
+contResultType (StrictArg _ _ _ _ cont) = contResultType cont
contResultType (StrictBind _ _ _ _ cont) = contResultType cont
contResultType (ApplyTo _ _ _ cont) = contResultType cont
contResultType (CoerceIt _ cont) = contResultType cont
splitInlineCont (ApplyTo dup (Type ty) se c)
| Just (c1, c2) <- splitInlineCont c = Just (ApplyTo dup (Type ty) se c1, c2)
-splitInlineCont cont@(Stop ty _ _) = Just (mkBoringStop ty, cont)
+splitInlineCont cont@(Stop ty _) = Just (mkBoringStop ty, cont)
splitInlineCont cont@(StrictBind bndr _ _ se _) = Just (mkBoringStop (substTy se (idType bndr)), cont)
-splitInlineCont cont@(StrictArg _ fun_ty _ _) = Just (mkBoringStop (funArgTy fun_ty), cont)
+splitInlineCont cont@(StrictArg _ fun_ty _ _ _) = Just (mkBoringStop (funArgTy fun_ty), cont)
splitInlineCont other = Nothing
-- NB: the calculation of the type for mkBoringStop is an annoying
-- duplication of the same calucation in mkDupableCont
\begin{code}
-interestingCallContext :: SimplCont -> CallContInfo
+interestingCallContext :: SimplCont -> CallCtxt
interestingCallContext cont
= interesting cont
where
+ interestingCtxt = ArgCtxt False 2 -- Give *some* incentive!
+
interesting (Select _ bndr _ _ _)
- | isDeadBinder bndr = CaseCont
- | otherwise = InterestingCont
+ | isDeadBinder bndr = CaseCtxt
+ | otherwise = interestingCtxt
- interesting (ApplyTo {}) = InterestingCont
- -- Can happen if we have (coerce t (f x)) y
- -- Perhaps True is a bit over-keen, but I've
- -- seen (coerce f) x, where f has an INLINE prag,
- -- So we have to give some motivation for inlining it
- interesting (StrictArg {}) = InterestingCont
- interesting (StrictBind {}) = InterestingCont
- interesting (Stop ty _ yes) = if yes then InterestingCont else BoringCont
- interesting (CoerceIt _ cont) = interesting cont
+ interesting (ApplyTo {}) = interestingCtxt
+ -- Can happen if we have (coerce t (f x)) y
+ -- Perhaps interestingCtxt is a bit over-keen, but I've
+ -- seen (coerce f) x, where f has an INLINE prag,
+ -- So we have to give some motivation for inlining it
+
+ interesting (StrictArg _ _ cci _ _) = cci
+ interesting (StrictBind {}) = BoringCtxt
+ interesting (Stop ty cci) = cci
+ interesting (CoerceIt _ cont) = interesting cont
-- If this call is the arg of a strict function, the context
-- is a bit interesting. If we inline here, we may get useful
-- evaluation information to avoid repeated evals: e.g.
mkArgInfo :: Id
-> Int -- Number of value args
-> SimplCont -- Context of the cal
- -> (Bool, [Bool]) -- Arg info
--- The arg info consists of
--- * A Bool indicating if the function has rules (recursively)
--- * A [Bool] indicating strictness for each arg
--- The [Bool] is usually infinite, but if it is finite it
--- guarantees that the function diverges after being given
--- that number of args
+ -> ArgInfo
mkArgInfo fun n_val_args call_cont
- = (interestingArgContext fun call_cont, fun_stricts)
+ = ArgInfo { ai_rules = interestingArgContext fun call_cont
+ , ai_strs = arg_stricts
+ , ai_discs = arg_discounts }
where
- vanilla_stricts, fun_stricts :: [Bool]
+ vanilla_discounts, arg_discounts :: [Int]
+ vanilla_discounts = repeat 0
+ arg_discounts = case idUnfolding fun of
+ CoreUnfolding _ _ _ _ (UnfoldIfGoodArgs _ discounts _ _)
+ -> discounts ++ vanilla_discounts
+ other -> vanilla_discounts
+
+ vanilla_stricts, arg_stricts :: [Bool]
vanilla_stricts = repeat False
- fun_stricts
+ arg_stricts
= case splitStrictSig (idNewStrictness fun) of
(demands, result_info)
| not (demands `lengthExceeds` n_val_args)
interestingArgContext fn call_cont
= idHasRules fn || go call_cont
where
- go (Select {}) = False
- go (ApplyTo {}) = False
- go (StrictArg {}) = True
- go (StrictBind {}) = False -- ??
- go (CoerceIt _ c) = go c
- go (Stop _ _ interesting) = interesting
+ go (Select {}) = False
+ go (ApplyTo {}) = False
+ go (StrictArg _ _ cci _ _) = interesting cci
+ go (StrictBind {}) = False -- ??
+ go (CoerceIt _ c) = go c
+ go (Stop _ cci) = interesting cci
+
+ interesting (ArgCtxt rules _) = rules
+ interesting other = False
\end{code}
import CoreSyn
import NewDemand ( isStrictDmd )
import PprCore ( pprParendExpr, pprCoreExpr )
-import CoreUnfold ( mkUnfolding, callSiteInline )
+import CoreUnfold ( mkUnfolding, callSiteInline, CallCtxt(..) )
import CoreUtils
import Rules ( lookupRule )
import BasicTypes ( isMarkedStrict )
Stop {} -> return (env, expr)
CoerceIt co cont -> rebuild env (mkCoerce co expr) cont
Select _ bndr alts se cont -> rebuildCase (se `setFloats` env) expr bndr alts cont
- StrictArg fun ty info cont -> rebuildCall env (fun `App` expr) (funResultTy ty) info cont
+ StrictArg fun ty _ info cont -> rebuildCall env (fun `App` expr) (funResultTy ty) info cont
StrictBind b bs body se cont -> do { env' <- simplNonRecX (se `setFloats` env) b expr
; simplLam env' bs body cont }
ApplyTo _ arg se cont -> do { arg' <- simplExpr (se `setInScope` env) arg
rebuildCall :: SimplEnv
-> OutExpr -> OutType -- Function and its type
- -> (Bool, [Bool]) -- See SimplUtils.mkArgInfo
+ -> ArgInfo
-> SimplCont
-> SimplM (SimplEnv, OutExpr)
-rebuildCall env fun fun_ty (has_rules, []) cont
+rebuildCall env fun fun_ty (ArgInfo { ai_strs = [] }) cont
-- When we run out of strictness args, it means
-- that the call is definitely bottom; see SimplUtils.mkArgInfo
-- Then we want to discard the entire strict continuation. E.g.
= do { ty' <- simplType (se `setInScope` env) arg_ty
; rebuildCall env (fun `App` Type ty') (applyTy fun_ty ty') info cont }
-rebuildCall env fun fun_ty (has_rules, str:strs) (ApplyTo _ arg arg_se cont)
+rebuildCall env fun fun_ty
+ (ArgInfo { ai_rules = has_rules, ai_strs = str:strs, ai_discs = disc:discs })
+ (ApplyTo _ arg arg_se cont)
| str || isStrictType arg_ty -- Strict argument
= -- pprTrace "Strict Arg" (ppr arg $$ ppr (seIdSubst env) $$ ppr (seInScope env)) $
simplExprF (arg_se `setFloats` env) arg
- (StrictArg fun fun_ty (has_rules, strs) cont)
+ (StrictArg fun fun_ty cci arg_info' cont)
-- Note [Shadowing]
| otherwise -- Lazy argument
-- have to be very careful about bogus strictness through
-- floating a demanded let.
= do { arg' <- simplExprC (arg_se `setInScope` env) arg
- (mkLazyArgStop arg_ty has_rules)
- ; rebuildCall env (fun `App` arg') res_ty (has_rules, strs) cont }
+ (mkLazyArgStop arg_ty cci)
+ ; rebuildCall env (fun `App` arg') res_ty arg_info' cont }
where
(arg_ty, res_ty) = splitFunTy fun_ty
+ arg_info' = ArgInfo { ai_rules = has_rules, ai_strs = strs, ai_discs = discs }
+ cci | has_rules || disc > 0 = ArgCtxt has_rules disc -- Be keener here
+ | otherwise = BoringCtxt -- Nothing interesting
rebuildCall env fun fun_ty info cont
= rebuild env fun cont
= return (env, mkBoringStop (substTy se (idType bndr)), cont)
-- See Note [Duplicating strict continuations]
-mkDupableCont env cont@(StrictArg _ fun_ty _ _)
+mkDupableCont env cont@(StrictArg _ fun_ty _ _ _)
= return (env, mkBoringStop (funArgTy fun_ty), cont)
-- See Note [Duplicating strict continuations]
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