%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[CoreSyn]{A data type for the Haskell compiler midsection}
\begin{code}
-#include "HsVersions.h"
-
module CoreSyn (
- GenCoreBinding(..), GenCoreExpr(..),
- GenCoreArg(..),GenCoreBinder(..), GenCoreCaseAlts(..),
- GenCoreCaseDefault(..),
-
- bindersOf, pairsFromCoreBinds, rhssOfBind,
-
- mkGenApp, mkValApp, mkTyApp, mkUseApp,
- mkApp, mkCon, mkPrim,
- mkValLam, mkTyLam, mkUseLam,
- mkLam,
- digForLambdas,
-
- collectArgs, isValArg,
-
- mkCoLetAny, mkCoLetNoUnboxed, mkCoLetUnboxedToCase,
- mkCoLetsAny, mkCoLetsNoUnboxed, mkCoLetsUnboxedToCase,
- mkCoLetrecAny, mkCoLetrecNoUnboxed,
-
- rhssOfAlts,
-
- -- Common type instantiation...
- CoreBinding(..),
- CoreExpr(..),
- CoreBinder(..),
- CoreArg(..),
- CoreCaseAlts(..),
- CoreCaseDefault(..),
-
- -- And not-so-common type instantiations...
- TaggedCoreBinding(..),
- TaggedCoreExpr(..),
- TaggedCoreBinder(..),
- TaggedCoreArg(..),
- TaggedCoreCaseAlts(..),
- TaggedCoreCaseDefault(..),
-
- SimplifiableCoreBinding(..),
- SimplifiableCoreExpr(..),
- SimplifiableCoreBinder(..),
- SimplifiableCoreArg(..),
- SimplifiableCoreCaseAlts(..),
- SimplifiableCoreCaseDefault(..)
-
- -- and to make the interface self-sufficient ...
-
+ Expr(..), Alt, Bind(..), AltCon(..), Arg, Note(..),
+ CoreExpr, CoreAlt, CoreBind, CoreArg, CoreBndr,
+ TaggedExpr, TaggedAlt, TaggedBind, TaggedArg, TaggedBndr(..),
+
+ mkLets, mkLams,
+ mkApps, mkTyApps, mkValApps, mkVarApps,
+ mkLit, mkIntLitInt, mkIntLit,
+ mkConApp,
+ varToCoreExpr,
+
+ isTyVar, isId, cmpAltCon, cmpAlt, ltAlt,
+ bindersOf, bindersOfBinds, rhssOfBind, rhssOfAlts,
+ collectBinders, collectTyBinders, collectValBinders, collectTyAndValBinders,
+ collectArgs,
+ coreExprCc,
+ flattenBinds,
+
+ isValArg, isTypeArg, valArgCount, valBndrCount, isRuntimeArg, isRuntimeVar,
+
+ -- Unfoldings
+ Unfolding(..), UnfoldingGuidance(..), -- Both abstract everywhere but in CoreUnfold.lhs
+ noUnfolding, evaldUnfolding, mkOtherCon,
+ unfoldingTemplate, maybeUnfoldingTemplate, otherCons,
+ isValueUnfolding, isEvaldUnfolding, isCheapUnfolding, isCompulsoryUnfolding,
+ hasUnfolding, hasSomeUnfolding, neverUnfold,
+
+ -- Seq stuff
+ seqExpr, seqExprs, seqUnfolding,
+
+ -- Annotated expressions
+ AnnExpr, AnnExpr'(..), AnnBind(..), AnnAlt,
+ deAnnotate, deAnnotate', deAnnAlt, collectAnnBndrs,
+
+ -- Core rules
+ CoreRule(..), -- CoreSubst, CoreTidy, CoreFVs, PprCore only
+ RuleName, seqRules,
+ isBuiltinRule, ruleName, isLocalRule, ruleIdName
) where
-import Ubiq{-uitous-}
-
-import CostCentre ( showCostCentre, CostCentre )
-import Id ( idType )
-import Usage ( UVar(..) )
-import Util ( panic, assertPanic )
+#include "HsVersions.h"
-isUnboxedDataType = panic "CoreSyn.isUnboxedDataType"
---eqId :: Id -> Id -> Bool
-eqId = panic "CoreSyn.eqId"
+import StaticFlags ( opt_RuntimeTypes )
+import CostCentre ( CostCentre, noCostCentre )
+import Var ( Var, Id, TyVar, isTyVar, isId )
+import Type ( Type, mkTyVarTy, seqType )
+import Name ( Name )
+import OccName ( OccName )
+import Literal ( Literal, mkMachInt )
+import DataCon ( DataCon, dataConWorkId, dataConTag )
+import BasicTypes ( Activation )
+import FastString
+import Outputable
\end{code}
%************************************************************************
%* *
-\subsection[CoreTopBinding_and_CoreBinding]{@CoreTopBinding@ and @GenCoreBinding@}
+\subsection{The main data types}
%* *
%************************************************************************
-Core programs, bindings, expressions, etc., are parameterised with
-respect to the information kept about binding and bound occurrences of
-variables, called {\em binders} and {\em val_occ tyvar uvars}, respectively. [I
-don't really like the pair of names; I prefer {\em binder} and {\em
-bounder}. Or {\em binder} and {\em var}.]
+These data types are the heart of the compiler
-A @GenCoreBinding@ is either a single non-recursive binding of a
-``binder'' to an expression, or a mutually-recursive blob of same.
\begin{code}
-data GenCoreBinding val_bdr val_occ tyvar uvar
- = NonRec val_bdr (GenCoreExpr val_bdr val_occ tyvar uvar)
- | Rec [(val_bdr, GenCoreExpr val_bdr val_occ tyvar uvar)]
+infixl 8 `App` -- App brackets to the left
+
+data Expr b -- "b" for the type of binders,
+ = Var Id
+ | Lit Literal
+ | App (Expr b) (Arg b)
+ | Lam b (Expr b)
+ | Let (Bind b) (Expr b)
+ | Case (Expr b) b Type [Alt b] -- Binder gets bound to value of scrutinee
+ -- Invariant: The list of alternatives is ALWAYS EXHAUSTIVE,
+ -- meaning that it covers all cases that can occur
+ -- See the example below
+ --
+ -- Invariant: The DEFAULT case must be *first*, if it occurs at all
+ -- Invariant: The remaining cases are in order of increasing
+ -- tag (for DataAlts)
+ -- lit (for LitAlts)
+ -- This makes finding the relevant constructor easy,
+ -- and makes comparison easier too
+ | Note Note (Expr b)
+ | Type Type -- This should only show up at the top
+ -- level of an Arg
+
+-- An "exhausive" case does not necessarily mention all constructors:
+-- data Foo = Red | Green | Blue
+--
+-- ...case x of
+-- Red -> True
+-- other -> f (case x of
+-- Green -> ...
+-- Blue -> ... )
+-- The inner case does not need a Red alternative, because x can't be Red at
+-- that program point.
+
+
+type Arg b = Expr b -- Can be a Type
+
+type Alt b = (AltCon, [b], Expr b) -- (DEFAULT, [], rhs) is the default alternative
+
+data AltCon = DataAlt DataCon
+ | LitAlt Literal
+ | DEFAULT
+ deriving (Eq, Ord)
+
+
+data Bind b = NonRec b (Expr b)
+ | Rec [(b, (Expr b))]
+
+data Note
+ = SCC CostCentre
+
+ | Coerce
+ Type -- The to-type: type of whole coerce expression
+ Type -- The from-type: type of enclosed expression
+
+ | InlineCall -- Instructs simplifier to inline
+ -- the enclosed call
+
+ | InlineMe -- Instructs 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.
\end{code}
-\begin{code}
-bindersOf :: GenCoreBinding val_bdr val_occ tyvar uvar -> [val_bdr]
+INVARIANTS:
-pairsFromCoreBinds ::
- [GenCoreBinding val_bdr val_occ tyvar uvar] ->
- [(val_bdr, GenCoreExpr val_bdr val_occ tyvar uvar)]
+* The RHS of a letrec, and the RHSs of all top-level lets,
+ must be of LIFTED type.
-rhssOfBind :: GenCoreBinding val_bdr val_occ tyvar uvar -> [GenCoreExpr val_bdr val_occ tyvar uvar]
+* The RHS of a let, 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. e.g.
+ y::Int# = x +# 1# ok
+ y::Int# = fac 4# not ok [use case instead]
-bindersOf (NonRec binder _) = [binder]
-bindersOf (Rec pairs) = [binder | (binder, _) <- pairs]
+* The argument of an App can be of any type.
-pairsFromCoreBinds [] = []
-pairsFromCoreBinds ((NonRec b e) : bs) = (b,e) : pairsFromCoreBinds bs
-pairsFromCoreBinds ((Rec pairs) : bs) = pairs ++ pairsFromCoreBinds bs
+* The simplifier tries to ensure that if the RHS of a let is a constructor
+ application, its arguments are trivial, so that the constructor can be
+ inlined vigorously.
-rhssOfBind (NonRec _ rhs) = [rhs]
-rhssOfBind (Rec pairs) = [rhs | (_,rhs) <- pairs]
-\end{code}
%************************************************************************
%* *
-\subsection[GenCoreExpr]{Core expressions: @GenCoreExpr@}
+\subsection{Transformation rules}
%* *
%************************************************************************
-@GenCoreExpr@ is the heart of the ``core'' data types; it is
-(more-or-less) boiled-down second-order polymorphic lambda calculus.
-For types in the core world, we just keep using @Types@.
-\begin{code}
-data GenCoreExpr val_bdr val_occ tyvar uvar
- = Var val_occ
- | Lit Literal -- literal constants
-\end{code}
+The CoreRule type and its friends are dealt with mainly in CoreRules,
+but CoreFVs, Subst, PprCore, CoreTidy also inspect the representation.
-@Cons@ and @Prims@ are saturated constructor and primitive-op
-applications (see the comment). Note: @Con@s are only set up by the
-simplifier (and by the desugarer when it knows what it's doing). The
-desugarer sets up constructors as applications of global @Vars@s.
+A Rule is
-\begin{code}
- | Con Id [GenCoreArg val_occ tyvar uvar]
- -- Saturated constructor application:
- -- The constructor is a function of the form:
- -- /\ a1 -> ... /\ am -> \ b1 -> ... \ bn ->
- -- <expr> where "/\" is a type lambda and "\" the
- -- regular kind; there will be "m" Types and
- -- "n" bindees in the Con args.
-
- | Prim PrimOp [GenCoreArg val_occ tyvar uvar]
- -- saturated primitive operation;
- -- comment on Cons applies here, too.
-\end{code}
+ "local" if the function it is a rule for is defined in the
+ same module as the rule itself.
+
+ "orphan" if nothing on the LHS is defined in the same module
+ as the rule itself
-Ye olde abstraction and application operators.
\begin{code}
- | Lam (GenCoreBinder val_bdr tyvar uvar)
- (GenCoreExpr val_bdr val_occ tyvar uvar)
+type RuleName = FastString
- | App (GenCoreExpr val_bdr val_occ tyvar uvar)
- (GenCoreArg val_occ tyvar uvar)
-\end{code}
+data CoreRule
+ = Rule {
+ ru_name :: RuleName,
+ 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 at the head of this rule
+ ru_rough :: [Maybe Name], -- Name at the head of each argument
+
+ -- Proper-matching stuff
+ -- see comments with InstEnv.Instance( is_tvs, is_tys )
+ ru_bndrs :: [CoreBndr], -- Forall'd variables
+ ru_args :: [CoreExpr], -- LHS args
+
+ -- And the right-hand side
+ ru_rhs :: CoreExpr,
-Case expressions (\tr{case <expr> of <List of alternatives>}): there
-are really two flavours masquerading here---those for scrutinising
-{\em algebraic} types and those for {\em primitive} types. Please see
-under @GenCoreCaseAlts@.
-\begin{code}
- | Case (GenCoreExpr val_bdr val_occ tyvar uvar)
- (GenCoreCaseAlts val_bdr val_occ tyvar uvar)
-\end{code}
+ -- Locality
+ ru_local :: Bool, -- The fn at the head of the rule is
+ -- defined in the same module as the rule
-A Core case expression \tr{case e of v -> ...} implies evaluation of
-\tr{e}; it is not equivalent to \tr{let v = in ...} (as with a Haskell
-\tr{case}).
+ -- Orphan-hood; see comments is InstEnv.Instance( is_orph )
+ ru_orph :: Maybe OccName }
-Non-recursive @Lets@ only have one binding; having more than one
-doesn't buy you much, and it is an easy way to mess up variable
-scoping.
-\begin{code}
- | Let (GenCoreBinding val_bdr val_occ tyvar uvar)
- (GenCoreExpr val_bdr val_occ tyvar uvar)
- -- both recursive and non-.
- -- The "GenCoreBinding" records that information
-\end{code}
+ | BuiltinRule { -- Built-in rules are used for constant folding
+ ru_name :: RuleName, -- and suchlike. It has no free variables.
+ ru_fn :: Name, -- Name of the Id at
+ -- the head of this rule
+ ru_try :: [CoreExpr] -> Maybe CoreExpr }
-For cost centre scc expressions we introduce a new core construct
-@SCC@ so transforming passes have to deal with it explicitly. The
-alternative of using a new PrimativeOp may result in a bad
-transformations of which we are unaware.
-\begin{code}
- | SCC CostCentre -- label of scc
- (GenCoreExpr val_bdr val_occ tyvar uvar) -- scc expression
+isBuiltinRule (BuiltinRule {}) = True
+isBuiltinRule _ = False
+
+ruleName :: CoreRule -> RuleName
+ruleName = ru_name
+
+ruleIdName :: CoreRule -> Name
+ruleIdName = ru_fn
+
+isLocalRule :: CoreRule -> Bool
+isLocalRule = ru_local
\end{code}
%************************************************************************
%* *
-\subsection{Core-constructing functions with checking}
+ Unfoldings
%* *
%************************************************************************
-When making @Lets@, we may want to take evasive action if the thing
-being bound has unboxed type. We have different variants ...
-
-@mkCoLet(s|rec)Any@ let-binds any binding, regardless of type
-@mkCoLet(s|rec)NoUnboxed@ prohibits unboxed bindings
-@mkCoLet(s)UnboxedToCase@ converts an unboxed binding to a case
- (unboxed bindings in a letrec are still prohibited)
+The @Unfolding@ type is declared here to avoid numerous loops, but it
+should be abstract everywhere except in CoreUnfold.lhs
\begin{code}
-mkCoLetAny :: GenCoreBinding val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-mkCoLetsAny :: [GenCoreBinding val_bdr val_occ tyvar uvar] ->
- GenCoreExpr val_bdr val_occ tyvar uvar ->
- GenCoreExpr val_bdr val_occ tyvar uvar
-mkCoLetrecAny :: [(val_bdr, GenCoreExpr val_bdr val_occ tyvar uvar)]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-
-mkCoLetrecAny [] body = body
-mkCoLetrecAny binds body = Let (Rec binds) body
-
-mkCoLetsAny [] expr = expr
-mkCoLetsAny binds expr = foldr mkCoLetAny expr binds
-
-mkCoLetAny bind@(Rec binds) body = mkCoLetrecAny binds body
-mkCoLetAny bind@(NonRec binder rhs) body
- = case body of
- Var binder2 | binder `eqId` binder2
- -> rhs -- hey, I have the rhs
- other
- -> Let bind body
+data Unfolding
+ = NoUnfolding
+
+ | OtherCon [AltCon] -- It ain't one of these
+ -- (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 -- An unfolding with redundant cached information
+ CoreExpr -- Template; binder-info is correct
+ Bool -- True <=> top level binding
+ Bool -- exprIsHNF template (cached); it is ok to discard a `seq` on
+ -- this variable
+ Bool -- True <=> doesn't waste (much) work to expand inside an inlining
+ -- Basically it's exprIsCheap
+ UnfoldingGuidance -- Tells about the *size* of the template.
+
+
+data UnfoldingGuidance
+ = UnfoldNever
+ | UnfoldIfGoodArgs Int -- and "n" value 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 -- The "size" of the unfolding; to be elaborated
+ -- later. ToDo
+
+ 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.)
+
+noUnfolding = NoUnfolding
+evaldUnfolding = OtherCon []
+
+mkOtherCon = OtherCon
+
+seqUnfolding :: Unfolding -> ()
+seqUnfolding (CoreUnfolding e top b1 b2 g)
+ = seqExpr e `seq` top `seq` b1 `seq` b2 `seq` seqGuidance g
+seqUnfolding other = ()
+
+seqGuidance (UnfoldIfGoodArgs n ns a b) = n `seq` sum ns `seq` a `seq` b `seq` ()
+seqGuidance other = ()
\end{code}
\begin{code}
---mkCoLetNoUnboxed ::
--- GenCoreBinding val_bdr val_occ tyvar uvar ->
--- GenCoreExpr val_bdr val_occ tyvar uvar ->
--- GenCoreExpr val_bdr val_occ tyvar uvar
-
-mkCoLetNoUnboxed bind@(Rec binds) body
- = mkCoLetrecNoUnboxed binds body
-mkCoLetNoUnboxed bind@(NonRec binder rhs) body
- = --ASSERT (not (isUnboxedDataType (idType binder)))
- case body of
- Var binder2 | binder `eqId` binder2
- -> rhs -- hey, I have the rhs
- other
- -> Let bind body
-
-mkCoLetsNoUnboxed [] expr = expr
-mkCoLetsNoUnboxed binds expr = foldr mkCoLetNoUnboxed expr binds
-
---mkCoLetrecNoUnboxed :: [(Id, CoreExpr)] -- bindings
--- -> CoreExpr -- body
--- -> CoreExpr -- result
-
-mkCoLetrecNoUnboxed [] body = body
-mkCoLetrecNoUnboxed binds body
- = ASSERT (all is_boxed_bind binds)
- Let (Rec binds) body
- where
- is_boxed_bind (binder, rhs)
- = (not . isUnboxedDataType . idType) binder
+unfoldingTemplate :: Unfolding -> CoreExpr
+unfoldingTemplate (CoreUnfolding expr _ _ _ _) = expr
+unfoldingTemplate (CompulsoryUnfolding expr) = expr
+unfoldingTemplate other = panic "getUnfoldingTemplate"
+
+maybeUnfoldingTemplate :: Unfolding -> Maybe CoreExpr
+maybeUnfoldingTemplate (CoreUnfolding expr _ _ _ _) = Just expr
+maybeUnfoldingTemplate (CompulsoryUnfolding expr) = Just expr
+maybeUnfoldingTemplate other = Nothing
+
+otherCons :: Unfolding -> [AltCon]
+otherCons (OtherCon cons) = cons
+otherCons other = []
+
+isValueUnfolding :: Unfolding -> Bool
+ -- Returns False for OtherCon
+isValueUnfolding (CoreUnfolding _ _ is_evald _ _) = is_evald
+isValueUnfolding other = False
+
+isEvaldUnfolding :: Unfolding -> Bool
+ -- Returns True for OtherCon
+isEvaldUnfolding (OtherCon _) = True
+isEvaldUnfolding (CoreUnfolding _ _ is_evald _ _) = is_evald
+isEvaldUnfolding other = False
+
+isCheapUnfolding :: Unfolding -> Bool
+isCheapUnfolding (CoreUnfolding _ _ _ is_cheap _) = is_cheap
+isCheapUnfolding other = False
+
+isCompulsoryUnfolding :: Unfolding -> Bool
+isCompulsoryUnfolding (CompulsoryUnfolding _) = True
+isCompulsoryUnfolding other = False
+
+hasUnfolding :: Unfolding -> Bool
+hasUnfolding (CoreUnfolding _ _ _ _ _) = True
+hasUnfolding (CompulsoryUnfolding _) = True
+hasUnfolding other = False
+
+hasSomeUnfolding :: Unfolding -> Bool
+hasSomeUnfolding NoUnfolding = False
+hasSomeUnfolding other = True
+
+neverUnfold :: Unfolding -> Bool
+neverUnfold NoUnfolding = True
+neverUnfold (OtherCon _) = True
+neverUnfold (CoreUnfolding _ _ _ _ UnfoldNever) = True
+neverUnfold other = False
\end{code}
-\begin{code}
---mkCoLetUnboxedToCase ::
--- GenCoreBinding val_bdr val_occ tyvar uvar ->
--- GenCoreExpr val_bdr val_occ tyvar uvar ->
--- GenCoreExpr val_bdr val_occ tyvar uvar
-
-mkCoLetUnboxedToCase bind@(Rec binds) body
- = mkCoLetrecNoUnboxed binds body
-mkCoLetUnboxedToCase bind@(NonRec binder rhs) body
- = case body of
- Var binder2 | binder `eqId` binder2
- -> rhs -- hey, I have the rhs
- other
- -> if (not (isUnboxedDataType (idType binder))) then
- Let bind body -- boxed...
- else
- Case rhs -- unboxed...
- (PrimAlts []
- (BindDefault binder body))
-
-mkCoLetsUnboxedToCase [] expr = expr
-mkCoLetsUnboxedToCase binds expr = foldr mkCoLetUnboxedToCase expr binds
-\end{code}
%************************************************************************
%* *
-\subsection{Case alternatives in @GenCoreExpr@}
+\subsection{The main data type}
%* *
%************************************************************************
-We have different kinds of @case@s, the differences being reflected in
-the kinds of alternatives a case has. We maintain a distinction
-between cases for scrutinising algebraic datatypes, as opposed to
-primitive types. In both cases, we carry around a @TyCon@, as a
-handle with which we can get info about the case (e.g., total number
-of data constructors for this type).
-
-For example:
-\begin{verbatim}
-let# x=e in b
-\end{verbatim}
-becomes
-\begin{verbatim}
-Case e [ BindDefaultAlt x -> b ]
-\end{verbatim}
-
\begin{code}
-data GenCoreCaseAlts val_bdr val_occ tyvar uvar
- = AlgAlts [(Id, -- alts: data constructor,
- [val_bdr], -- constructor's parameters,
- GenCoreExpr val_bdr val_occ tyvar uvar)] -- rhs.
- (GenCoreCaseDefault val_bdr val_occ tyvar uvar)
-
- | PrimAlts [(Literal, -- alts: unboxed literal,
- GenCoreExpr val_bdr val_occ tyvar uvar)] -- rhs.
- (GenCoreCaseDefault val_bdr val_occ tyvar uvar)
-
--- obvious things: if there are no alts in the list, then the default
--- can't be NoDefault.
-
-data GenCoreCaseDefault val_bdr val_occ tyvar uvar
- = NoDefault -- small con family: all
- -- constructor accounted for
- | BindDefault val_bdr -- form: var -> expr;
- (GenCoreExpr val_bdr val_occ tyvar uvar) -- "val_bdr" may or may not
- -- be used in RHS.
+-- The Ord is needed for the FiniteMap used in the lookForConstructor
+-- in SimplEnv. If you declared that lookForConstructor *ignores*
+-- constructor-applications with LitArg args, then you could get
+-- rid of this Ord.
+
+instance Outputable AltCon where
+ ppr (DataAlt dc) = ppr dc
+ ppr (LitAlt lit) = ppr lit
+ ppr DEFAULT = ptext SLIT("__DEFAULT")
+
+instance Show AltCon where
+ showsPrec p con = showsPrecSDoc p (ppr con)
+
+cmpAlt :: Alt b -> Alt b -> Ordering
+cmpAlt (con1, _, _) (con2, _, _) = con1 `cmpAltCon` con2
+
+ltAlt :: Alt b -> Alt b -> Bool
+ltAlt a1 a2 = case a1 `cmpAlt` a2 of { LT -> True; other -> False }
+
+cmpAltCon :: AltCon -> AltCon -> Ordering
+-- Compares AltCons within a single list of alternatives
+cmpAltCon DEFAULT DEFAULT = EQ
+cmpAltCon DEFAULT con = LT
+
+cmpAltCon (DataAlt d1) (DataAlt d2) = dataConTag d1 `compare` dataConTag d2
+cmpAltCon (DataAlt _) DEFAULT = GT
+cmpAltCon (LitAlt l1) (LitAlt l2) = l1 `compare` l2
+cmpAltCon (LitAlt _) DEFAULT = GT
+
+cmpAltCon con1 con2 = WARN( True, text "Comparing incomparable AltCons" <+>
+ ppr con1 <+> ppr con2 )
+ LT
\end{code}
-\begin{code}
-rhssOfAlts (AlgAlts alts deflt) = rhssOfDeflt deflt ++ [rhs | (_,_,rhs) <- alts]
-rhssOfAlts (PrimAlts alts deflt) = rhssOfDeflt deflt ++ [rhs | (_,rhs) <- alts]
-
-rhssOfDeflt NoDefault = []
-rhssOfDeflt (BindDefault _ rhs) = [rhs]
-\end{code}
%************************************************************************
%* *
-\subsection{Core binders}
+\subsection{Useful synonyms}
%* *
%************************************************************************
+The common case
+
\begin{code}
-data GenCoreBinder val_bdr tyvar uvar
- = ValBinder val_bdr
- | TyBinder tyvar
- | UsageBinder uvar
+type CoreBndr = Var
+type CoreExpr = Expr CoreBndr
+type CoreArg = Arg CoreBndr
+type CoreBind = Bind CoreBndr
+type CoreAlt = Alt CoreBndr
\end{code}
-Clump Lams together if possible.
+Binders are ``tagged'' with a \tr{t}:
\begin{code}
-mkValLam :: [val_bdr]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-mkTyLam :: [tyvar]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-mkUseLam :: [uvar]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-
-mkValLam binders body = foldr (Lam . ValBinder) body binders
-mkTyLam binders body = foldr (Lam . TyBinder) body binders
-mkUseLam binders body = foldr (Lam . UsageBinder) body binders
-
-mkLam :: [tyvar] -> [val_bdr] -- ToDo: could add a [uvar] arg...
- -> GenCoreExpr val_bdr val_occ tyvar uvar
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-
-mkLam tyvars valvars body
- = mkTyLam tyvars (mkValLam valvars body)
-\end{code}
+data TaggedBndr t = TB CoreBndr t -- TB for "tagged binder"
-We often want to strip off leading lambdas before getting down to
-business. @digForLambdas@ is your friend.
+type TaggedBind t = Bind (TaggedBndr t)
+type TaggedExpr t = Expr (TaggedBndr t)
+type TaggedArg t = Arg (TaggedBndr t)
+type TaggedAlt t = Alt (TaggedBndr t)
-We expect (by convention) usage-, type-, and value- lambdas in that
-order.
+instance Outputable b => Outputable (TaggedBndr b) where
+ ppr (TB b l) = char '<' <> ppr b <> comma <> ppr l <> char '>'
-\begin{code}
-digForLambdas ::
- GenCoreExpr val_bdr val_occ tyvar uvar ->
- ([uvar], [tyvar], [val_bdr], GenCoreExpr val_bdr val_occ tyvar uvar)
-
-digForLambdas (Lam (UsageBinder u) body)
- = let
- (uvars, tyvars, args, final_body) = digForLambdas body
- in
- (u:uvars, tyvars, args, final_body)
-
-digForLambdas other
- = let
- (tyvars, args, body) = dig_for_tyvars other
- in
- ([], tyvars, args, body)
- where
- dig_for_tyvars (Lam (TyBinder tv) body)
- = let
- (tyvars, args, body2) = dig_for_tyvars body
- in
- (tv : tyvars, args, body2)
-
- dig_for_tyvars body
- = ASSERT(not (usage_lambda body))
- let
- (args, body2) = dig_for_valvars body
- in
- ([], args, body2)
-
- ---------------------------------------
- dig_for_valvars (Lam (ValBinder v) body)
- = let
- (args, body2) = dig_for_valvars body
- in
- (v : args, body2)
-
- dig_for_valvars body
- = ASSERT(not (usage_lambda body))
- ASSERT(not (tyvar_lambda body))
- ([], body)
-
- ---------------------------------------
- usage_lambda (Lam (UsageBinder _) _) = True
- usage_lambda _ = False
-
- tyvar_lambda (Lam (TyBinder _) _) = True
- tyvar_lambda _ = False
+instance Outputable b => OutputableBndr (TaggedBndr b) where
+ pprBndr _ b = ppr b -- Simple
\end{code}
+
%************************************************************************
%* *
-\subsection{Core arguments (atoms)}
+\subsection{Core-constructing functions with checking}
%* *
%************************************************************************
\begin{code}
-data GenCoreArg val_occ tyvar uvar
- = LitArg Literal
- | VarArg val_occ
- | TyArg (GenType tyvar uvar)
- | UsageArg (GenUsage uvar)
+mkApps :: Expr b -> [Arg b] -> Expr b
+mkTyApps :: Expr b -> [Type] -> Expr b
+mkValApps :: Expr b -> [Expr b] -> Expr b
+mkVarApps :: Expr b -> [Var] -> Expr b
+
+mkApps f args = foldl App f args
+mkTyApps f args = foldl (\ e a -> App e (Type a)) f args
+mkValApps f args = foldl (\ e a -> App e a) f args
+mkVarApps f vars = foldl (\ e a -> App e (varToCoreExpr a)) f vars
+
+mkLit :: Literal -> Expr b
+mkIntLit :: Integer -> Expr b
+mkIntLitInt :: Int -> Expr b
+mkConApp :: DataCon -> [Arg b] -> Expr b
+mkLets :: [Bind b] -> Expr b -> Expr b
+mkLams :: [b] -> Expr b -> Expr b
+
+mkLit lit = Lit lit
+mkConApp con args = mkApps (Var (dataConWorkId con)) args
+
+mkLams binders body = foldr Lam body binders
+mkLets binds body = foldr Let body binds
+
+mkIntLit n = Lit (mkMachInt n)
+mkIntLitInt n = Lit (mkMachInt (toInteger n))
+
+varToCoreExpr :: CoreBndr -> Expr b
+varToCoreExpr v | isId v = Var v
+ | otherwise = Type (mkTyVarTy v)
\end{code}
-General and specific forms:
+
+%************************************************************************
+%* *
+\subsection{Simple access functions}
+%* *
+%************************************************************************
+
\begin{code}
-mkGenApp :: GenCoreExpr val_bdr val_occ tyvar uvar
- -> [GenCoreArg val_occ tyvar uvar]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-mkTyApp :: GenCoreExpr val_bdr val_occ tyvar uvar
- -> [GenType tyvar uvar]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-mkUseApp :: GenCoreExpr val_bdr val_occ tyvar uvar
- -> [GenUsage uvar]
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-mkValApp :: GenCoreExpr val_bdr val_occ tyvar uvar
- -> [GenCoreArg val_occ tyvar uvar] -- but we ASSERT they are LitArg or VarArg
- -> GenCoreExpr val_bdr val_occ tyvar uvar
-
-mkGenApp f args = foldl App f args
-mkTyApp f args = foldl (\ e a -> App e (TyArg a)) f args
-mkUseApp f args = foldl (\ e a -> App e (UsageArg a)) f args
-mkValApp f args = foldl (\ e a -> App e (is_Lit_or_Var a)) f args
-
-#ifndef DEBUG
-is_Lit_or_Var a = a
-#else
-is_Lit_or_Var a
- = if isValArg a then a else panic "CoreSyn.mkValApps:not LitArg or VarArg"
-#endif
-
-isValArg (LitArg _) = True -- often used for sanity-checking
-isValArg (VarArg _) = True
-isValArg _ = False
+bindersOf :: Bind b -> [b]
+bindersOf (NonRec binder _) = [binder]
+bindersOf (Rec pairs) = [binder | (binder, _) <- pairs]
+
+bindersOfBinds :: [Bind b] -> [b]
+bindersOfBinds binds = foldr ((++) . bindersOf) [] binds
+
+rhssOfBind :: Bind b -> [Expr b]
+rhssOfBind (NonRec _ rhs) = [rhs]
+rhssOfBind (Rec pairs) = [rhs | (_,rhs) <- pairs]
+
+rhssOfAlts :: [Alt b] -> [Expr b]
+rhssOfAlts alts = [e | (_,_,e) <- alts]
+
+flattenBinds :: [Bind b] -> [(b, Expr b)] -- Get all the lhs/rhs pairs
+flattenBinds (NonRec b r : binds) = (b,r) : flattenBinds binds
+flattenBinds (Rec prs1 : binds) = prs1 ++ flattenBinds binds
+flattenBinds [] = []
\end{code}
+We often want to strip off leading lambdas before getting down to
+business. @collectBinders@ is your friend.
+
+We expect (by convention) type-, and value- lambdas in that
+order.
+
\begin{code}
-mkApp fun = mk_thing (mkGenApp fun)
-mkCon con = mk_thing (Con con)
-mkPrim op = mk_thing (Prim op)
+collectBinders :: Expr b -> ([b], Expr b)
+collectTyBinders :: CoreExpr -> ([TyVar], CoreExpr)
+collectValBinders :: CoreExpr -> ([Id], CoreExpr)
+collectTyAndValBinders :: CoreExpr -> ([TyVar], [Id], CoreExpr)
+
+collectBinders expr
+ = go [] expr
+ where
+ go bs (Lam b e) = go (b:bs) e
+ go bs e = (reverse bs, e)
+
+collectTyAndValBinders expr
+ = (tvs, ids, body)
+ where
+ (tvs, body1) = collectTyBinders expr
+ (ids, body) = collectValBinders body1
-mk_thing thing uses tys vals
- = thing (map UsageArg uses ++ map TyArg tys ++ map is_Lit_or_Var vals)
+collectTyBinders expr
+ = go [] expr
+ where
+ go tvs (Lam b e) | isTyVar b = go (b:tvs) e
+ go tvs e = (reverse tvs, e)
+
+collectValBinders expr
+ = go [] expr
+ where
+ go ids (Lam b e) | isId b = go (b:ids) e
+ go ids body = (reverse ids, body)
\end{code}
+
@collectArgs@ takes an application expression, returning the function
and the arguments to which it is applied.
\begin{code}
-collectArgs :: GenCoreExpr val_bdr val_occ tyvar uvar
- -> (GenCoreExpr val_bdr val_occ tyvar uvar,
- [GenCoreArg val_occ tyvar uvar])
-
+collectArgs :: Expr b -> (Expr b, [Arg b])
collectArgs expr
- = collect expr []
+ = go expr []
where
- collect (App fun arg) args = collect fun (arg : args)
- collect fun args = (fun, args)
+ go (App f a) as = go f (a:as)
+ go e as = (e, as)
\end{code}
+coreExprCc gets the cost centre enclosing an expression, if any.
+It looks inside lambdas because (scc "foo" \x.e) = \x.scc "foo" e
+
+\begin{code}
+coreExprCc :: Expr b -> CostCentre
+coreExprCc (Note (SCC cc) e) = cc
+coreExprCc (Note other_note e) = coreExprCc e
+coreExprCc (Lam _ e) = coreExprCc e
+coreExprCc other = noCostCentre
+\end{code}
+
+
+
%************************************************************************
%* *
-\subsection{The main @Core*@ instantiation of the @GenCore*@ types}
+\subsection{Predicates}
%* *
%************************************************************************
+@isRuntimeVar v@ returns if (Lam v _) really becomes a lambda at runtime,
+i.e. if type applications are actual lambdas because types are kept around
+at runtime.
+
+Similarly isRuntimeArg.
+
\begin{code}
-type CoreBinding = GenCoreBinding Id Id TyVar UVar
-type CoreExpr = GenCoreExpr Id Id TyVar UVar
-type CoreBinder = GenCoreBinder Id TyVar UVar
-type CoreArg = GenCoreArg Id TyVar UVar
+isRuntimeVar :: Var -> Bool
+isRuntimeVar | opt_RuntimeTypes = \v -> True
+ | otherwise = \v -> isId v
+
+isRuntimeArg :: CoreExpr -> Bool
+isRuntimeArg | opt_RuntimeTypes = \e -> True
+ | otherwise = \e -> isValArg e
+\end{code}
+
+\begin{code}
+isValArg (Type _) = False
+isValArg other = True
+
+isTypeArg (Type _) = True
+isTypeArg other = False
+
+valBndrCount :: [CoreBndr] -> Int
+valBndrCount [] = 0
+valBndrCount (b : bs) | isId b = 1 + valBndrCount bs
+ | otherwise = valBndrCount bs
-type CoreCaseAlts = GenCoreCaseAlts Id Id TyVar UVar
-type CoreCaseDefault = GenCoreCaseDefault Id Id TyVar UVar
+valArgCount :: [Arg b] -> Int
+valArgCount [] = 0
+valArgCount (Type _ : args) = valArgCount args
+valArgCount (other : args) = 1 + valArgCount args
\end{code}
+
%************************************************************************
%* *
-\subsection{The @TaggedCore*@ instantiation of the @GenCore*@ types}
+\subsection{Seq stuff}
%* *
%************************************************************************
-Binders are ``tagged'' with a \tr{t}:
\begin{code}
-type Tagged t = (Id, t)
+seqExpr :: CoreExpr -> ()
+seqExpr (Var v) = v `seq` ()
+seqExpr (Lit lit) = lit `seq` ()
+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
+-- gaw 2004
+seqExpr (Case e b t as) = seqExpr e `seq` seqBndr b `seq` seqType t `seq` seqAlts as
+seqExpr (Note n e) = seqNote n `seq` seqExpr e
+seqExpr (Type t) = seqType t
+
+seqExprs [] = ()
+seqExprs (e:es) = seqExpr e `seq` seqExprs es
+
+seqNote (Coerce t1 t2) = seqType t1 `seq` seqType t2
+seqNote (CoreNote s) = s `seq` ()
+seqNote other = ()
+
+seqBndr b = b `seq` ()
+
+seqBndrs [] = ()
+seqBndrs (b:bs) = seqBndr b `seq` seqBndrs bs
+
+seqBind (NonRec b e) = seqBndr b `seq` seqExpr e
+seqBind (Rec prs) = seqPairs prs
+
+seqPairs [] = ()
+seqPairs ((b,e):prs) = seqBndr b `seq` seqExpr e `seq` seqPairs prs
+
+seqAlts [] = ()
+seqAlts ((c,bs,e):alts) = seqBndrs bs `seq` seqExpr e `seq` seqAlts alts
+
+seqRules [] = ()
+seqRules (Rule { ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs } : rules)
+ = seqBndrs bndrs `seq` seqExprs (rhs:args) `seq` seqRules rules
+seqRules (BuiltinRule {} : rules) = seqRules rules
+\end{code}
-type TaggedCoreBinding t = GenCoreBinding (Tagged t) Id TyVar UVar
-type TaggedCoreExpr t = GenCoreExpr (Tagged t) Id TyVar UVar
-type TaggedCoreBinder t = GenCoreBinder (Tagged t) TyVar UVar
-type TaggedCoreArg t = GenCoreArg Id TyVar UVar
-type TaggedCoreCaseAlts t = GenCoreCaseAlts (Tagged t) Id TyVar UVar
-type TaggedCoreCaseDefault t = GenCoreCaseDefault (Tagged t) Id TyVar UVar
-\end{code}
%************************************************************************
%* *
-\subsection{The @SimplifiableCore*@ instantiation of the @GenCore*@ types}
+\subsection{Annotated core; annotation at every node in the tree}
%* *
%************************************************************************
-Binders are tagged with @BinderInfo@:
\begin{code}
-type Simplifiable = (Id, BinderInfo)
+type AnnExpr bndr annot = (annot, AnnExpr' bndr annot)
+
+data AnnExpr' bndr annot
+ = AnnVar Id
+ | AnnLit Literal
+ | AnnLam bndr (AnnExpr bndr annot)
+ | AnnApp (AnnExpr bndr annot) (AnnExpr bndr annot)
+-- gaw 2004
+ | AnnCase (AnnExpr bndr annot) bndr Type [AnnAlt bndr annot]
+ | AnnLet (AnnBind bndr annot) (AnnExpr bndr annot)
+ | AnnNote Note (AnnExpr bndr annot)
+ | AnnType Type
+
+type AnnAlt bndr annot = (AltCon, [bndr], AnnExpr bndr annot)
+
+data AnnBind bndr annot
+ = AnnNonRec bndr (AnnExpr bndr annot)
+ | AnnRec [(bndr, AnnExpr bndr annot)]
+\end{code}
+
+\begin{code}
+deAnnotate :: AnnExpr bndr annot -> Expr bndr
+deAnnotate (_, e) = deAnnotate' e
+
+deAnnotate' (AnnType t) = Type t
+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' (AnnNote note body) = Note note (deAnnotate body)
+
+deAnnotate' (AnnLet bind body)
+ = Let (deAnnBind bind) (deAnnotate body)
+ where
+ deAnnBind (AnnNonRec var rhs) = NonRec var (deAnnotate rhs)
+ deAnnBind (AnnRec pairs) = Rec [(v,deAnnotate rhs) | (v,rhs) <- pairs]
+
+-- gaw 2004
+deAnnotate' (AnnCase scrut v t alts)
+ = Case (deAnnotate scrut) v t (map deAnnAlt alts)
-type SimplifiableCoreBinding = GenCoreBinding Simplifiable Id TyVar UVar
-type SimplifiableCoreExpr = GenCoreExpr Simplifiable Id TyVar UVar
-type SimplifiableCoreBinder = GenCoreBinder Simplifiable TyVar UVar
-type SimplifiableCoreArg = GenCoreArg Id TyVar UVar
+deAnnAlt :: AnnAlt bndr annot -> Alt bndr
+deAnnAlt (con,args,rhs) = (con,args,deAnnotate rhs)
+\end{code}
-type SimplifiableCoreCaseAlts = GenCoreCaseAlts Simplifiable Id TyVar UVar
-type SimplifiableCoreCaseDefault = GenCoreCaseDefault Simplifiable Id TyVar UVar
+\begin{code}
+collectAnnBndrs :: AnnExpr bndr annot -> ([bndr], AnnExpr bndr annot)
+collectAnnBndrs e
+ = collect [] e
+ where
+ collect bs (_, AnnLam b body) = collect (b:bs) body
+ collect bs body = (reverse bs, body)
\end{code}
projects / ghc-hetmet.git / blobdiff