X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FcoreSyn%2FCoreSyn.lhs;h=e754c6dda5d7e936a6aa3e4a8c5feb812eee8a87;hp=1b3a9d7b68fc4949d55b2d4ebf4bf98b03c59961;hb=8133a9f47b99f4e65ed30551de32ad72c6b61b27;hpb=9ffadf219cbc4f8ec57264786df936a3cee88aec diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs index 1b3a9d7..e754c6d 100644 --- a/compiler/coreSyn/CoreSyn.lhs +++ b/compiler/coreSyn/CoreSyn.lhs @@ -4,6 +4,7 @@ % \begin{code} +{-# LANGUAGE DeriveDataTypeable, DeriveFunctor #-} -- | CoreSyn holds all the main data types for use by for the Glasgow Haskell Compiler midsection module CoreSyn ( @@ -14,7 +15,7 @@ module CoreSyn ( -- ** 'Expr' construction mkLets, mkLams, - mkApps, mkTyApps, mkVarApps, + mkApps, mkTyApps, mkCoApps, mkVarApps, mkIntLit, mkIntLitInt, mkWordLit, mkWordLitWord, @@ -22,28 +23,36 @@ module CoreSyn ( mkFloatLit, mkFloatLitFloat, mkDoubleLit, mkDoubleLitDouble, - mkConApp, mkTyBind, + mkConApp, mkTyBind, mkCoBind, varToCoreExpr, varsToCoreExprs, - isTyVar, isId, cmpAltCon, cmpAlt, ltAlt, + isId, cmpAltCon, cmpAlt, ltAlt, -- ** Simple 'Expr' access functions and predicates bindersOf, bindersOfBinds, rhssOfBind, rhssOfAlts, collectBinders, collectTyBinders, collectValBinders, collectTyAndValBinders, collectArgs, coreExprCc, flattenBinds, - isValArg, isTypeArg, valArgCount, valBndrCount, isRuntimeArg, isRuntimeVar, + isValArg, isTypeArg, isTyCoArg, valArgCount, valBndrCount, + isRuntimeArg, isRuntimeVar, + notSccNote, -- * Unfolding data types - Unfolding(..), UnfoldingGuidance(..), -- Both abstract everywhere but in CoreUnfold.lhs - + Unfolding(..), UnfoldingGuidance(..), UnfoldingSource(..), + DFunArg(..), dfunArgExprs, + -- ** Constructing 'Unfolding's noUnfolding, evaldUnfolding, mkOtherCon, + unSaturatedOk, needSaturated, boringCxtOk, boringCxtNotOk, -- ** Predicates and deconstruction on 'Unfolding' - unfoldingTemplate, maybeUnfoldingTemplate, otherCons, - isValueUnfolding, isEvaldUnfolding, isCheapUnfolding, isCompulsoryUnfolding, - hasUnfolding, hasSomeUnfolding, neverUnfold, + unfoldingTemplate, setUnfoldingTemplate, expandUnfolding_maybe, + maybeUnfoldingTemplate, otherCons, unfoldingArity, + isValueUnfolding, isEvaldUnfolding, isCheapUnfolding, + isExpandableUnfolding, isConLikeUnfolding, isCompulsoryUnfolding, + isStableUnfolding, isStableCoreUnfolding_maybe, + isClosedUnfolding, hasSomeUnfolding, + canUnfold, neverUnfoldGuidance, isStableSource, -- * Strictness seqExpr, seqExprs, seqUnfolding, @@ -51,17 +60,23 @@ module CoreSyn ( -- * Annotated expression data types AnnExpr, AnnExpr'(..), AnnBind(..), AnnAlt, + -- ** Operations on annotated expressions + collectAnnArgs, + -- ** Operations on annotations deAnnotate, deAnnotate', deAnnAlt, collectAnnBndrs, -- * Core rule data types CoreRule(..), -- CoreSubst, CoreTidy, CoreFVs, PprCore only - RuleName, + RuleName, IdUnfoldingFun, -- ** Operations on 'CoreRule's - seqRules, ruleArity, ruleName, ruleIdName, ruleActivation_maybe, + seqRules, ruleArity, ruleName, ruleIdName, ruleActivation, setRuleIdName, - isBuiltinRule, isLocalRule + isBuiltinRule, isLocalRule, + + -- * Core vectorisation declarations data type + CoreVect(..) ) where #include "HsVersions.h" @@ -78,9 +93,10 @@ import FastString import Outputable import Util +import Data.Data import Data.Word -infixl 4 `mkApps`, `mkTyApps`, `mkVarApps` +infixl 4 `mkApps`, `mkTyApps`, `mkVarApps`, `App`, `mkCoApps` -- Left associative, so that we can say (f `mkTyApps` xs `mkVarApps` ys) \end{code} @@ -93,8 +109,6 @@ infixl 4 `mkApps`, `mkTyApps`, `mkVarApps` These data types are the heart of the compiler \begin{code} -infixl 8 `App` -- App brackets to the left - -- | This is the data type that represents GHCs core intermediate language. Currently -- GHC uses System FC for this purpose, -- which is closely related to the simpler and better known System F . @@ -130,11 +144,15 @@ infixl 8 `App` -- App brackets to the left -- The type parameter @b@ is for the type of binders in the expression tree. data Expr b = Var Id -- ^ Variables + | Lit Literal -- ^ Primitive literals + | App (Expr b) (Arg b) -- ^ Applications: note that the argument may be a 'Type'. -- -- See "CoreSyn#let_app_invariant" for another invariant + | Lam b (Expr b) -- ^ Lambda abstraction + | Let (Bind b) (Expr b) -- ^ Recursive and non recursive @let@s. Operationally -- this corresponds to allocating a thunk for the things -- bound and then executing the sub-expression. @@ -147,14 +165,16 @@ data Expr b -- the meaning of /lifted/ vs. /unlifted/). -- -- #let_app_invariant# - -- The right hand side of of a non-recursive 'Let' _and_ the argument of an 'App', + -- The right hand side of of a non-recursive 'Let' + -- _and_ the argument of an 'App', -- /may/ be of unlifted type, but only if the expression - -- is ok-for-speculation. This means that the let can be floated around - -- without difficulty. For example, this is OK: + -- is ok-for-speculation. This means that the let can be floated + -- around without difficulty. For example, this is OK: -- -- > y::Int# = x +# 1# -- - -- But this is not, as it may affect termination if the expression is floated out: + -- But this is not, as it may affect termination if the + -- expression is floated out: -- -- > y::Int# = fac 4# -- @@ -174,6 +194,7 @@ data Expr b -- At the moment, the rest of the compiler only deals with type-let -- in a Let expression, rather than at top level. We may want to revist -- this choice. + | Case (Expr b) b Type [Alt b] -- ^ Case split. Operationally this corresponds to evaluating -- the scrutinee (expression examined) to weak head normal form -- and then examining at most one level of resulting constructor (i.e. you @@ -183,15 +204,17 @@ data Expr b -- and the 'Type' must be that of all the case alternatives -- -- #case_invariants# - -- This is one of the more complicated elements of the Core language, and comes - -- with a number of restrictions: + -- This is one of the more complicated elements of the Core language, + -- and comes with a number of restrictions: -- - -- The 'DEFAULT' case alternative must be first in the list, if it occurs at all. + -- The 'DEFAULT' case alternative must be first in the list, + -- if it occurs at all. -- -- The remaining cases are in order of increasing -- tag (for 'DataAlts') or -- lit (for 'LitAlts'). - -- This makes finding the relevant constructor easy, and makes comparison easier too. + -- This makes finding the relevant constructor easy, + -- and makes comparison easier too. -- -- The list of alternatives must be exhaustive. An /exhaustive/ case -- does not necessarily mention all constructors: @@ -205,14 +228,21 @@ data Expr b -- Blue -> ... ) ... -- @ -- - -- The inner case does not need a @Red@ alternative, because @x@ can't be @Red@ at - -- that program point. - | Cast (Expr b) Coercion -- ^ Cast an expression to a particular type. This is used to implement @newtype@s - -- (a @newtype@ constructor or destructor just becomes a 'Cast' in Core) and GADTs. + -- The inner case does not need a @Red@ alternative, because @x@ + -- can't be @Red@ at that program point. + + | Cast (Expr b) Coercion -- ^ Cast an expression to a particular type. + -- This is used to implement @newtype@s (a @newtype@ constructor or + -- destructor just becomes a 'Cast' in Core) and GADTs. + | Note Note (Expr b) -- ^ Notes. These allow general information to be -- added to expressions in the syntax tree + | Type Type -- ^ A type: this should only show up at the top -- level of an Arg + + | Coercion Coercion -- ^ A coercion + deriving (Data, Typeable) -- | Type synonym for expressions that occur in function argument positions. -- Only 'Arg' should contain a 'Type' at top level, general 'Expr' should not @@ -228,11 +258,12 @@ data AltCon = DataAlt DataCon -- ^ A plain data constructor: @case e of { Foo x -- Invariant: the 'DataCon' is always from a @data@ type, and never from a @newtype@ | LitAlt Literal -- ^ A literal: @case e of { 1 -> ... }@ | DEFAULT -- ^ Trivial alternative: @case e of { _ -> ... }@ - deriving (Eq, Ord) + deriving (Eq, Ord, Data, Typeable) -- | Binding, used for top level bindings in a module and local bindings in a @let@. data Bind b = NonRec b (Expr b) | Rec [(b, (Expr b))] + deriving (Data, Typeable) \end{code} -------------------------- CoreSyn INVARIANTS --------------------------- @@ -271,21 +302,8 @@ See #type_let# -- | Allows attaching extra information to points in expressions rather than e.g. identifiers. data Note = SCC CostCentre -- ^ A cost centre annotation for profiling - - | InlineMe -- ^ Instructs the core simplifer to treat the enclosed expression - -- as very small, and inline it at its call sites - | CoreNote String -- ^ A generic core annotation, propagated but not used by GHC - --- NOTE: we also treat expressions wrapped in InlineMe as --- 'cheap' and 'dupable' (in the sense of exprIsCheap, exprIsDupable) --- What this means is that we obediently inline even things that don't --- look like valuse. This is sometimes important: --- {-# INLINE f #-} --- f = g . h --- Here, f looks like a redex, and we aren't going to inline (.) because it's --- inside an INLINE, so it'll stay looking like a redex. Nevertheless, we --- should inline f even inside lambdas. In effect, we should trust the programmer. + deriving (Data, Typeable) \end{code} @@ -310,7 +328,7 @@ data CoreRule = Rule { ru_name :: RuleName, -- ^ Name of the rule, for communication with the user ru_act :: Activation, -- ^ When the rule is active - + -- Rough-matching stuff -- see comments with InstEnv.Instance( is_cls, is_rough ) ru_fn :: Name, -- ^ Name of the 'Id.Id' at the head of this rule @@ -323,8 +341,14 @@ data CoreRule -- And the right-hand side ru_rhs :: CoreExpr, -- ^ Right hand side of the rule + -- Occurrence info is guaranteed correct + -- See Note [OccInfo in unfoldings and rules] -- Locality + ru_auto :: Bool, -- ^ @True@ <=> this rule is auto-generated + -- @False@ <=> generated at the users behest + -- Main effect: reporting of orphan-hood + ru_local :: Bool -- ^ @True@ iff the fn at the head of the rule is -- defined in the same module as the rule -- and is not an implicit 'Id' (like a record selector, @@ -337,17 +361,22 @@ data CoreRule -- | Built-in rules are used for constant folding -- and suchlike. They have no free variables. | BuiltinRule { - ru_name :: RuleName, -- ^ As above - ru_fn :: Name, -- ^ As above - ru_nargs :: Int, -- ^ Number of arguments that 'ru_try' expects, - -- including type arguments - ru_try :: [CoreExpr] -> Maybe CoreExpr + ru_name :: RuleName, -- ^ As above + ru_fn :: Name, -- ^ As above + ru_nargs :: Int, -- ^ Number of arguments that 'ru_try' consumes, + -- if it fires, including type arguments + ru_try :: IdUnfoldingFun -> [CoreExpr] -> Maybe CoreExpr -- ^ This function does the rewrite. It given too many -- arguments, it simply discards them; the returned 'CoreExpr' -- is just the rewrite of 'ru_fn' applied to the first 'ru_nargs' args } -- See Note [Extra args in rule matching] in Rules.lhs +type IdUnfoldingFun = Id -> Unfolding +-- A function that embodies how to unfold an Id if you need +-- to do that in the Rule. The reason we need to pass this info in +-- is that whether an Id is unfoldable depends on the simplifier phase + isBuiltinRule :: CoreRule -> Bool isBuiltinRule (BuiltinRule {}) = True isBuiltinRule _ = False @@ -361,9 +390,9 @@ ruleArity (Rule {ru_args = args}) = length args ruleName :: CoreRule -> RuleName ruleName = ru_name -ruleActivation_maybe :: CoreRule -> Maybe Activation -ruleActivation_maybe (BuiltinRule { }) = Nothing -ruleActivation_maybe (Rule { ru_act = act }) = Just act +ruleActivation :: CoreRule -> Activation +ruleActivation (BuiltinRule { }) = AlwaysActive +ruleActivation (Rule { ru_act = act }) = act -- | The 'Name' of the 'Id.Id' at the head of the rule left hand side ruleIdName :: CoreRule -> Name @@ -379,6 +408,20 @@ setRuleIdName nm ru = ru { ru_fn = nm } %************************************************************************ +%* * +\subsection{Vectorisation declarations} +%* * +%************************************************************************ + +Representation of desugared vectorisation declarations that are fed to the vectoriser (via +'ModGuts'). + +\begin{code} +data CoreVect = Vect Id (Maybe CoreExpr) +\end{code} + + +%************************************************************************ %* * Unfoldings %* * @@ -391,58 +434,185 @@ The @Unfolding@ type is declared here to avoid numerous loops -- identifier would have if we substituted its definition in for the identifier. -- This type should be treated as abstract everywhere except in "CoreUnfold" data Unfolding - = NoUnfolding -- ^ We have no information about the unfolding - - | OtherCon [AltCon] -- ^ It ain't one of these constructors. - -- @OtherCon xs@ also indicates that something has been evaluated - -- and hence there's no point in re-evaluating it. - -- @OtherCon []@ is used even for non-data-type values - -- to indicated evaluated-ness. Notably: - -- - -- > data C = C !(Int -> Int) - -- > case x of { C f -> ... } - -- - -- Here, @f@ gets an @OtherCon []@ unfolding. - - | CompulsoryUnfolding CoreExpr -- ^ There is /no original definition/, - -- so you'd better unfold. - - | CoreUnfolding - CoreExpr - Bool - Bool - Bool - UnfoldingGuidance + = NoUnfolding -- ^ We have no information about the unfolding + + | OtherCon [AltCon] -- ^ It ain't one of these constructors. + -- @OtherCon xs@ also indicates that something has been evaluated + -- and hence there's no point in re-evaluating it. + -- @OtherCon []@ is used even for non-data-type values + -- to indicated evaluated-ness. Notably: + -- + -- > data C = C !(Int -> Int) + -- > case x of { C f -> ... } + -- + -- Here, @f@ gets an @OtherCon []@ unfolding. + + | DFunUnfolding -- The Unfolding of a DFunId + -- See Note [DFun unfoldings] + -- df = /\a1..am. \d1..dn. MkD (op1 a1..am d1..dn) + -- (op2 a1..am d1..dn) + + Arity -- Arity = m+n, the *total* number of args + -- (unusually, both type and value) to the dfun + + DataCon -- The dictionary data constructor (possibly a newtype datacon) + + [DFunArg CoreExpr] -- Specification of superclasses and methods, in positional order + + | CoreUnfolding { -- An unfolding for an Id with no pragma, + -- or perhaps a NOINLINE pragma + -- (For NOINLINE, the phase, if any, is in the + -- InlinePragInfo for this Id.) + uf_tmpl :: CoreExpr, -- Template; occurrence info is correct + uf_src :: UnfoldingSource, -- Where the unfolding came from + uf_is_top :: Bool, -- True <=> top level binding + uf_arity :: Arity, -- Number of value arguments expected + uf_is_value :: Bool, -- exprIsHNF template (cached); it is ok to discard + -- a `seq` on this variable + uf_is_conlike :: Bool, -- True <=> applicn of constructor or CONLIKE function + -- Cached version of exprIsConLike + uf_is_cheap :: Bool, -- True <=> doesn't waste (much) work to expand + -- inside an inlining + -- Cached version of exprIsCheap + uf_expandable :: Bool, -- True <=> can expand in RULE matching + -- Cached version of exprIsExpandable + uf_guidance :: UnfoldingGuidance -- Tells about the *size* of the template. + } -- ^ An unfolding with redundant cached information. Parameters: -- - -- 1) Template used to perform unfolding; binder-info is correct + -- uf_tmpl: Template used to perform unfolding; + -- NB: Occurrence info is guaranteed correct: + -- see Note [OccInfo in unfoldings and rules] -- - -- 2) Is this a top level binding? + -- uf_is_top: Is this a top level binding? -- - -- 3) 'exprIsHNF' template (cached); it is ok to discard a 'seq' on + -- uf_is_value: 'exprIsHNF' template (cached); it is ok to discard a 'seq' on -- this variable -- - -- 4) Does this waste only a little work if we expand it inside an inlining? + -- uf_is_cheap: Does this waste only a little work if we expand it inside an inlining? -- Basically this is a cached version of 'exprIsCheap' -- - -- 5) Tells us about the /size/ of the unfolding template - --- | When unfolding should take place + -- uf_guidance: Tells us about the /size/ of the unfolding template + +------------------------------------------------ +data DFunArg e -- Given (df a b d1 d2 d3) + = DFunPolyArg e -- Arg is (e a b d1 d2 d3) + | DFunConstArg e -- Arg is e, which is constant + | DFunLamArg Int -- Arg is one of [a,b,d1,d2,d3], zero indexed + deriving( Functor ) + + -- 'e' is often CoreExpr, which are usually variables, but can + -- be trivial expressions instead (e.g. a type application). + +dfunArgExprs :: [DFunArg e] -> [e] +dfunArgExprs [] = [] +dfunArgExprs (DFunPolyArg e : as) = e : dfunArgExprs as +dfunArgExprs (DFunConstArg e : as) = e : dfunArgExprs as +dfunArgExprs (DFunLamArg {} : as) = dfunArgExprs as + + +------------------------------------------------ +data UnfoldingSource + = InlineRhs -- The current rhs of the function + -- Replace uf_tmpl each time around + + | InlineStable -- From an INLINE or INLINABLE pragma + -- INLINE if guidance is UnfWhen + -- INLINABLE if guidance is UnfIfGoodArgs/UnfoldNever + -- (well, technically an INLINABLE might be made + -- UnfWhen if it was small enough, and then + -- it will behave like INLINE outside the current + -- module, but that is the way automatic unfoldings + -- work so it is consistent with the intended + -- meaning of INLINABLE). + -- + -- uf_tmpl may change, but only as a result of + -- gentle simplification, it doesn't get updated + -- to the current RHS during compilation as with + -- InlineRhs. + -- + -- See Note [InlineRules] + + | InlineCompulsory -- Something that *has* no binding, so you *must* inline it + -- Only a few primop-like things have this property + -- (see MkId.lhs, calls to mkCompulsoryUnfolding). + -- Inline absolutely always, however boring the context. + + | InlineWrapper Id -- This unfolding is a the wrapper in a + -- worker/wrapper split from the strictness analyser + -- The Id is the worker-id + -- Used to abbreviate the uf_tmpl in interface files + -- which don't need to contain the RHS; + -- it can be derived from the strictness info + + + +-- | 'UnfoldingGuidance' says when unfolding should take place data UnfoldingGuidance - = UnfoldNever - | UnfoldIfGoodArgs Int -- and "n" value args + = UnfWhen { -- Inline without thinking about the *size* of the uf_tmpl + -- Used (a) for small *and* cheap unfoldings + -- (b) for INLINE functions + -- See Note [INLINE for small functions] in CoreUnfold + ug_unsat_ok :: Bool, -- True <=> ok to inline even if unsaturated + ug_boring_ok :: Bool -- True <=> ok to inline even if the context is boring + -- So True,True means "always" + } - [Int] -- Discount if the argument is evaluated. - -- (i.e., a simplification will definitely - -- be possible). One elt of the list per *value* arg. + | UnfIfGoodArgs { -- Arose from a normal Id; the info here is the + -- result of a simple analysis of the RHS - Int -- The "size" of the unfolding; to be elaborated - -- later. ToDo + ug_args :: [Int], -- Discount if the argument is evaluated. + -- (i.e., a simplification will definitely + -- be possible). One elt of the list per *value* arg. - Int -- Scrutinee discount: the discount to substract if the thing is in - -- a context (case (thing args) of ...), - -- (where there are the right number of arguments.) + ug_size :: Int, -- The "size" of the unfolding. + ug_res :: Int -- Scrutinee discount: the discount to substract if the thing is in + } -- a context (case (thing args) of ...), + -- (where there are the right number of arguments.) + + | UnfNever -- The RHS is big, so don't inline it +\end{code} + + +Note [DFun unfoldings] +~~~~~~~~~~~~~~~~~~~~~~ +The Arity in a DFunUnfolding is total number of args (type and value) +that the DFun needs to produce a dictionary. That's not necessarily +related to the ordinary arity of the dfun Id, esp if the class has +one method, so the dictionary is represented by a newtype. Example + + class C a where { op :: a -> Int } + instance C a -> C [a] where op xs = op (head xs) + +The instance translates to + + $dfCList :: forall a. C a => C [a] -- Arity 2! + $dfCList = /\a.\d. $copList {a} d |> co + + $copList :: forall a. C a => [a] -> Int -- Arity 2! + $copList = /\a.\d.\xs. op {a} d (head xs) + +Now we might encounter (op (dfCList {ty} d) a1 a2) +and we want the (op (dfList {ty} d)) rule to fire, because $dfCList +has all its arguments, even though its (value) arity is 2. That's +why we record the number of expected arguments in the DFunUnfolding. + +Note that although it's an Arity, it's most convenient for it to give +the *total* number of arguments, both type and value. See the use +site in exprIsConApp_maybe. + +\begin{code} +-- Constants for the UnfWhen constructor +needSaturated, unSaturatedOk :: Bool +needSaturated = False +unSaturatedOk = True + +boringCxtNotOk, boringCxtOk :: Bool +boringCxtOk = True +boringCxtNotOk = False + +------------------------------------------------ noUnfolding :: Unfolding -- ^ There is no known 'Unfolding' evaldUnfolding :: Unfolding @@ -455,27 +625,38 @@ mkOtherCon :: [AltCon] -> Unfolding mkOtherCon = OtherCon seqUnfolding :: Unfolding -> () -seqUnfolding (CoreUnfolding e top b1 b2 g) - = seqExpr e `seq` top `seq` b1 `seq` b2 `seq` seqGuidance g +seqUnfolding (CoreUnfolding { uf_tmpl = e, uf_is_top = top, + uf_is_value = b1, uf_is_cheap = b2, + uf_expandable = b3, uf_is_conlike = b4, + uf_arity = a, uf_guidance = g}) + = seqExpr e `seq` top `seq` b1 `seq` a `seq` b2 `seq` b3 `seq` b4 `seq` seqGuidance g + seqUnfolding _ = () seqGuidance :: UnfoldingGuidance -> () -seqGuidance (UnfoldIfGoodArgs n ns a b) = n `seq` sum ns `seq` a `seq` b `seq` () -seqGuidance _ = () +seqGuidance (UnfIfGoodArgs ns n b) = n `seq` sum ns `seq` b `seq` () +seqGuidance _ = () \end{code} \begin{code} +isStableSource :: UnfoldingSource -> Bool +-- Keep the unfolding template +isStableSource InlineCompulsory = True +isStableSource InlineStable = True +isStableSource (InlineWrapper {}) = True +isStableSource InlineRhs = False + -- | Retrieves the template of an unfolding: panics if none is known unfoldingTemplate :: Unfolding -> CoreExpr -unfoldingTemplate (CoreUnfolding expr _ _ _ _) = expr -unfoldingTemplate (CompulsoryUnfolding expr) = expr -unfoldingTemplate _ = panic "getUnfoldingTemplate" +unfoldingTemplate = uf_tmpl + +setUnfoldingTemplate :: Unfolding -> CoreExpr -> Unfolding +setUnfoldingTemplate unf rhs = unf { uf_tmpl = rhs } -- | Retrieves the template of an unfolding if possible maybeUnfoldingTemplate :: Unfolding -> Maybe CoreExpr -maybeUnfoldingTemplate (CoreUnfolding expr _ _ _ _) = Just expr -maybeUnfoldingTemplate (CompulsoryUnfolding expr) = Just expr -maybeUnfoldingTemplate _ = Nothing +maybeUnfoldingTemplate (CoreUnfolding { uf_tmpl = expr }) = Just expr +maybeUnfoldingTemplate _ = Nothing -- | The constructors that the unfolding could never be: -- returns @[]@ if no information is available @@ -486,47 +667,123 @@ otherCons _ = [] -- | Determines if it is certainly the case that the unfolding will -- yield a value (something in HNF): returns @False@ if unsure isValueUnfolding :: Unfolding -> Bool -isValueUnfolding (CoreUnfolding _ _ is_evald _ _) = is_evald -isValueUnfolding _ = False + -- Returns False for OtherCon +isValueUnfolding (CoreUnfolding { uf_is_value = is_evald }) = is_evald +isValueUnfolding _ = False -- | Determines if it possibly the case that the unfolding will -- yield a value. Unlike 'isValueUnfolding' it returns @True@ -- for 'OtherCon' isEvaldUnfolding :: Unfolding -> Bool -isEvaldUnfolding (OtherCon _) = True -isEvaldUnfolding (CoreUnfolding _ _ is_evald _ _) = is_evald -isEvaldUnfolding _ = False + -- Returns True for OtherCon +isEvaldUnfolding (OtherCon _) = True +isEvaldUnfolding (CoreUnfolding { uf_is_value = is_evald }) = is_evald +isEvaldUnfolding _ = False + +-- | @True@ if the unfolding is a constructor application, the application +-- of a CONLIKE function or 'OtherCon' +isConLikeUnfolding :: Unfolding -> Bool +isConLikeUnfolding (OtherCon _) = True +isConLikeUnfolding (CoreUnfolding { uf_is_conlike = con }) = con +isConLikeUnfolding _ = False -- | Is the thing we will unfold into certainly cheap? isCheapUnfolding :: Unfolding -> Bool -isCheapUnfolding (CoreUnfolding _ _ _ is_cheap _) = is_cheap -isCheapUnfolding _ = False +isCheapUnfolding (CoreUnfolding { uf_is_cheap = is_cheap }) = is_cheap +isCheapUnfolding _ = False + +isExpandableUnfolding :: Unfolding -> Bool +isExpandableUnfolding (CoreUnfolding { uf_expandable = is_expable }) = is_expable +isExpandableUnfolding _ = False + +expandUnfolding_maybe :: Unfolding -> Maybe CoreExpr +-- Expand an expandable unfolding; this is used in rule matching +-- See Note [Expanding variables] in Rules.lhs +-- The key point here is that CONLIKE things can be expanded +expandUnfolding_maybe (CoreUnfolding { uf_expandable = True, uf_tmpl = rhs }) = Just rhs +expandUnfolding_maybe _ = Nothing + +isStableCoreUnfolding_maybe :: Unfolding -> Maybe UnfoldingSource +isStableCoreUnfolding_maybe (CoreUnfolding { uf_src = src }) + | isStableSource src = Just src +isStableCoreUnfolding_maybe _ = Nothing --- | Must this unfolding happen for the code to be executable? isCompulsoryUnfolding :: Unfolding -> Bool -isCompulsoryUnfolding (CompulsoryUnfolding _) = True -isCompulsoryUnfolding _ = False +isCompulsoryUnfolding (CoreUnfolding { uf_src = InlineCompulsory }) = True +isCompulsoryUnfolding _ = False --- | Do we have an available or compulsory unfolding? -hasUnfolding :: Unfolding -> Bool -hasUnfolding (CoreUnfolding _ _ _ _ _) = True -hasUnfolding (CompulsoryUnfolding _) = True -hasUnfolding _ = False +isStableUnfolding :: Unfolding -> Bool +-- True of unfoldings that should not be overwritten +-- by a CoreUnfolding for the RHS of a let-binding +isStableUnfolding (CoreUnfolding { uf_src = src }) = isStableSource src +isStableUnfolding (DFunUnfolding {}) = True +isStableUnfolding _ = False + +unfoldingArity :: Unfolding -> Arity +unfoldingArity (CoreUnfolding { uf_arity = arity }) = arity +unfoldingArity _ = panic "unfoldingArity" + +isClosedUnfolding :: Unfolding -> Bool -- No free variables +isClosedUnfolding (CoreUnfolding {}) = False +isClosedUnfolding (DFunUnfolding {}) = False +isClosedUnfolding _ = True -- | Only returns False if there is no unfolding information available at all hasSomeUnfolding :: Unfolding -> Bool hasSomeUnfolding NoUnfolding = False hasSomeUnfolding _ = True --- | Similar to @not . hasUnfolding@, but also returns @True@ --- if it has an unfolding that says it should never occur -neverUnfold :: Unfolding -> Bool -neverUnfold NoUnfolding = True -neverUnfold (OtherCon _) = True -neverUnfold (CoreUnfolding _ _ _ _ UnfoldNever) = True -neverUnfold _ = False +neverUnfoldGuidance :: UnfoldingGuidance -> Bool +neverUnfoldGuidance UnfNever = True +neverUnfoldGuidance _ = False + +canUnfold :: Unfolding -> Bool +canUnfold (CoreUnfolding { uf_guidance = g }) = not (neverUnfoldGuidance g) +canUnfold _ = False \end{code} +Note [InlineRules] +~~~~~~~~~~~~~~~~~ +When you say + {-# INLINE f #-} + f x = +you intend that calls (f e) are replaced by [e/x] So we +should capture (\x.) in the Unfolding of 'f', and never meddle +with it. Meanwhile, we can optimise to our heart's content, +leaving the original unfolding intact in Unfolding of 'f'. For example + all xs = foldr (&&) True xs + any p = all . map p {-# INLINE any #-} +We optimise any's RHS fully, but leave the InlineRule saying "all . map p", +which deforests well at the call site. + +So INLINE pragma gives rise to an InlineRule, which captures the original RHS. + +Moreover, it's only used when 'f' is applied to the +specified number of arguments; that is, the number of argument on +the LHS of the '=' sign in the original source definition. +For example, (.) is now defined in the libraries like this + {-# INLINE (.) #-} + (.) f g = \x -> f (g x) +so that it'll inline when applied to two arguments. If 'x' appeared +on the left, thus + (.) f g x = f (g x) +it'd only inline when applied to three arguments. This slightly-experimental +change was requested by Roman, but it seems to make sense. + +See also Note [Inlining an InlineRule] in CoreUnfold. + + +Note [OccInfo in unfoldings and rules] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +In unfoldings and rules, we guarantee that the template is occ-analysed, +so that the occurence info on the binders is correct. This is important, +because the Simplifier does not re-analyse the template when using it. If +the occurrence info is wrong + - We may get more simpifier iterations than necessary, because + once-occ info isn't there + - More seriously, we may get an infinite loop if there's a Rec + without a loop breaker marked + %************************************************************************ %* * @@ -624,6 +881,8 @@ instance Outputable b => OutputableBndr (TaggedBndr b) where mkApps :: Expr b -> [Arg b] -> Expr b -- | Apply a list of type argument expressions to a function expression in a nested fashion mkTyApps :: Expr b -> [Type] -> Expr b +-- | Apply a list of coercion argument expressions to a function expression in a nested fashion +mkCoApps :: Expr b -> [Coercion] -> Expr b -- | Apply a list of type or value variables to a function expression in a nested fashion mkVarApps :: Expr b -> [Var] -> Expr b -- | Apply a list of argument expressions to a data constructor in a nested fashion. Prefer to @@ -632,6 +891,7 @@ mkConApp :: DataCon -> [Arg b] -> Expr b mkApps f args = foldl App f args mkTyApps f args = foldl (\ e a -> App e (Type a)) f args +mkCoApps f args = foldl (\ e a -> App e (Coercion a)) f args mkVarApps f vars = foldl (\ e a -> App e (varToCoreExpr a)) f vars mkConApp con args = mkApps (Var (dataConWorkId con)) args @@ -702,10 +962,16 @@ mkLets binds body = foldr Let body binds mkTyBind :: TyVar -> Type -> CoreBind mkTyBind tv ty = NonRec tv (Type ty) +-- | Create a binding group where a type variable is bound to a type. Per "CoreSyn#type_let", +-- this can only be used to bind something in a non-recursive @let@ expression +mkCoBind :: CoVar -> Coercion -> CoreBind +mkCoBind cv co = NonRec cv (Coercion co) + -- | Convert a binder into either a 'Var' or 'Type' 'Expr' appropriately varToCoreExpr :: CoreBndr -> Expr b -varToCoreExpr v | isId v = Var v - | otherwise = Type (mkTyVarTy v) +varToCoreExpr v | isTyVar v = Type (mkTyVarTy v) + | isCoVar v = Coercion (mkCoVarCo v) + | otherwise = ASSERT( isId v ) Var v varsToCoreExprs :: [CoreBndr] -> [Expr b] varsToCoreExprs vs = map varToCoreExpr vs @@ -822,15 +1088,23 @@ isRuntimeVar = isId isRuntimeArg :: CoreExpr -> Bool isRuntimeArg = isValArg --- | Returns @False@ iff the expression is a 'Type' expression at its top level +-- | Returns @False@ iff the expression is a 'Type' or 'Coercion' +-- expression at its top level isValArg :: Expr b -> Bool -isValArg (Type _) = False -isValArg _ = True +isValArg e = not (isTypeArg e) + +-- | Returns @True@ iff the expression is a 'Type' or 'Coercion' +-- expression at its top level +isTyCoArg :: Expr b -> Bool +isTyCoArg (Type {}) = True +isTyCoArg (Coercion {}) = True +isTyCoArg _ = False --- | Returns @True@ iff the expression is a 'Type' expression at its top level +-- | Returns @True@ iff the expression is a 'Type' expression at its +-- top level. Note this does NOT include 'Coercion's. isTypeArg :: Expr b -> Bool -isTypeArg (Type _) = True -isTypeArg _ = False +isTypeArg (Type {}) = True +isTypeArg _ = False -- | The number of binders that bind values rather than types valBndrCount :: [CoreBndr] -> Int @@ -839,6 +1113,10 @@ valBndrCount = count isId -- | The number of argument expressions that are values rather than types at their top level valArgCount :: [Arg b] -> Int valArgCount = count isValArg + +notSccNote :: Note -> Bool +notSccNote (SCC {}) = False +notSccNote _ = True \end{code} @@ -856,9 +1134,10 @@ seqExpr (App f a) = seqExpr f `seq` seqExpr a seqExpr (Lam b e) = seqBndr b `seq` seqExpr e seqExpr (Let b e) = seqBind b `seq` seqExpr e seqExpr (Case e b t as) = seqExpr e `seq` seqBndr b `seq` seqType t `seq` seqAlts as -seqExpr (Cast e co) = seqExpr e `seq` seqType co +seqExpr (Cast e co) = seqExpr e `seq` seqCo co seqExpr (Note n e) = seqNote n `seq` seqExpr e -seqExpr (Type t) = seqType t +seqExpr (Type t) = seqType t +seqExpr (Coercion co) = seqCo co seqExprs :: [CoreExpr] -> () seqExprs [] = () @@ -912,9 +1191,11 @@ data AnnExpr' bndr annot | AnnApp (AnnExpr bndr annot) (AnnExpr bndr annot) | AnnCase (AnnExpr bndr annot) bndr Type [AnnAlt bndr annot] | AnnLet (AnnBind bndr annot) (AnnExpr bndr annot) - | AnnCast (AnnExpr bndr annot) Coercion + | AnnCast (AnnExpr bndr annot) (annot, Coercion) + -- Put an annotation on the (root of) the coercion | AnnNote Note (AnnExpr bndr annot) | AnnType Type + | AnnCoercion Coercion -- | A clone of the 'Alt' type but allowing annotation at every tree node type AnnAlt bndr annot = (AltCon, [bndr], AnnExpr bndr annot) @@ -926,16 +1207,28 @@ data AnnBind bndr annot \end{code} \begin{code} +-- | Takes a nested application expression and returns the the function +-- being applied and the arguments to which it is applied +collectAnnArgs :: AnnExpr b a -> (AnnExpr b a, [AnnExpr b a]) +collectAnnArgs expr + = go expr [] + where + go (_, AnnApp f a) as = go f (a:as) + go e as = (e, as) +\end{code} + +\begin{code} deAnnotate :: AnnExpr bndr annot -> Expr bndr deAnnotate (_, e) = deAnnotate' e deAnnotate' :: AnnExpr' bndr annot -> Expr bndr -deAnnotate' (AnnType t) = Type t +deAnnotate' (AnnType t) = Type t +deAnnotate' (AnnCoercion co) = Coercion co deAnnotate' (AnnVar v) = Var v deAnnotate' (AnnLit lit) = Lit lit deAnnotate' (AnnLam binder body) = Lam binder (deAnnotate body) deAnnotate' (AnnApp fun arg) = App (deAnnotate fun) (deAnnotate arg) -deAnnotate' (AnnCast e co) = Cast (deAnnotate e) co +deAnnotate' (AnnCast e (_,co)) = Cast (deAnnotate e) co deAnnotate' (AnnNote note body) = Note note (deAnnotate body) deAnnotate' (AnnLet bind body)