%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[CoreUtils]{Utility functions on @Core@ syntax}
+
+Utility functions on @Core@ syntax
\begin{code}
+{-# OPTIONS_GHC -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/WorkingConventions#Warnings
+-- for details
+
module CoreUtils (
-- Construction
- mkInlineMe, mkSCC, mkCoerce,
+ mkInlineMe, mkSCC, mkCoerce, mkCoerceI,
bindNonRec, needsCaseBinding,
mkIfThenElse, mkAltExpr, mkPiType, mkPiTypes,
-- Taking expressions apart
- findDefault, findAlt, isDefaultAlt, mergeAlts,
+ findDefault, findAlt, isDefaultAlt, mergeAlts, trimConArgs,
-- Properties of expressions
exprType, coreAltType,
#include "HsVersions.h"
-
-import GLAEXTS -- For `xori`
-
import CoreSyn
-import CoreFVs ( exprFreeVars )
-import PprCore ( pprCoreExpr )
-import Var ( Var, TyVar, CoVar, tyVarKind, mkCoVar, mkTyVar )
-import OccName ( mkVarOccFS )
-import SrcLoc ( noSrcLoc )
-import VarSet ( unionVarSet )
+import CoreFVs
+import PprCore
+import Var
+import SrcLoc
+import VarSet
import VarEnv
-import Name ( hashName, mkSysTvName )
+import Name
#if mingw32_TARGET_OS
-import Packages ( isDllName )
+import Packages
#endif
-import Literal ( hashLiteral, literalType, litIsDupable,
- litIsTrivial, isZeroLit, Literal( MachLabel ) )
-import DataCon ( DataCon, dataConRepArity, eqSpecPreds,
- dataConTyCon, dataConRepArgTys,
- dataConUnivTyVars, dataConExTyVars, dataConEqSpec,
- dataConOrigArgTys, dataConTheta )
-import PrimOp ( PrimOp(..), primOpOkForSpeculation, primOpIsCheap )
-import Id ( Id, idType, globalIdDetails, idNewStrictness,
- mkWildId, idArity, idName, idUnfolding, idInfo,
- isOneShotBndr, isStateHackType,
- isDataConWorkId_maybe, mkSysLocal, mkUserLocal,
- isDataConWorkId, isBottomingId, isDictId
- )
-import IdInfo ( GlobalIdDetails(..), megaSeqIdInfo )
-import NewDemand ( appIsBottom )
-import Type ( Type, mkFunTy, mkForAllTy, splitFunTy_maybe,
- splitFunTy, tcEqTypeX,
- applyTys, isUnLiftedType, seqType, mkTyVarTy,
- splitForAllTy_maybe, isForAllTy,
- splitTyConApp_maybe, splitTyConApp, coreEqType, funResultTy, applyTy,
- substTyWith, mkPredTy, zipOpenTvSubst, substTy, substTyVar
- )
-import Coercion ( Coercion, mkTransCoercion, coercionKind,
- splitNewTypeRepCo_maybe, mkSymCoercion,
- decomposeCo, coercionKindPredTy )
-import TyCon ( tyConArity )
-import TysWiredIn ( boolTy, trueDataCon, falseDataCon )
-import CostCentre ( CostCentre )
-import BasicTypes ( Arity )
-import PackageConfig ( PackageId )
-import Unique ( Unique )
+import Literal
+import DataCon
+import PrimOp
+import Id
+import IdInfo
+import NewDemand
+import Type
+import Coercion
+import TyCon
+import TysWiredIn
+import CostCentre
+import BasicTypes
+import PackageConfig
+import Unique
import Outputable
-import DynFlags ( DynFlags, DynFlag(Opt_DictsCheap), dopt )
-import TysPrim ( alphaTy ) -- Debugging only
-import Util ( equalLength, lengthAtLeast, foldl2 )
-import FastString ( FastString )
+import DynFlags
+import TysPrim
+import FastString
+import Maybes
+import Util
+import Data.Word
+import Data.Bits
+
+import GHC.Exts -- For `xori`
\end{code}
\begin{code}
exprType :: CoreExpr -> Type
-exprType (Var var) = idType var
-exprType (Lit lit) = literalType lit
-exprType (Let _ body) = exprType body
-exprType (Case _ _ ty alts) = ty
-exprType (Cast e co)
- = let (_, ty) = coercionKind co in ty
-exprType (Note other_note e) = exprType e
-exprType (Lam binder expr) = mkPiType binder (exprType expr)
+exprType (Var var) = idType var
+exprType (Lit lit) = literalType lit
+exprType (Let _ body) = exprType body
+exprType (Case _ _ ty alts) = ty
+exprType (Cast e co) = snd (coercionKind co)
+exprType (Note other_note e) = exprType e
+exprType (Lam binder expr) = mkPiType binder (exprType expr)
exprType e@(App _ _)
= case collectArgs e of
(fun, args) -> applyTypeToArgs e (exprType fun) args
\begin{code}
+mkCoerceI :: CoercionI -> CoreExpr -> CoreExpr
+mkCoerceI IdCo e = e
+mkCoerceI (ACo co) e = mkCoerce co e
+
mkCoerce :: Coercion -> CoreExpr -> CoreExpr
mkCoerce co (Cast expr co2)
= ASSERT(let { (from_ty, _to_ty) = coercionKind co;
= mkConApp con (map Type inst_tys ++ varsToCoreExprs args)
mkAltExpr (LitAlt lit) [] []
= Lit lit
+mkAltExpr (LitAlt _) _ _ = panic "mkAltExpr LitAlt"
+mkAltExpr DEFAULT _ _ = panic "mkAltExpr DEFAULT"
mkIfThenElse :: CoreExpr -> CoreExpr -> CoreExpr -> CoreExpr
mkIfThenElse guard then_expr else_expr
LT -> a1 : mergeAlts as1 (a2:as2)
EQ -> a1 : mergeAlts as1 as2 -- Discard a2
GT -> a2 : mergeAlts (a1:as1) as2
+
+
+---------------------------------
+trimConArgs :: AltCon -> [CoreArg] -> [CoreArg]
+-- Given case (C a b x y) of
+-- C b x y -> ...
+-- we want to drop the leading type argument of the scrutinee
+-- leaving the arguments to match agains the pattern
+
+trimConArgs DEFAULT args = ASSERT( null args ) []
+trimConArgs (LitAlt lit) args = ASSERT( null args ) []
+trimConArgs (DataAlt dc) args = dropList (dataConUnivTyVars dc) args
\end{code}
exprOkForSpeculation :: CoreExpr -> Bool
exprOkForSpeculation (Lit _) = True
exprOkForSpeculation (Type _) = True
+ -- Tick boxes are *not* suitable for speculation
exprOkForSpeculation (Var v) = isUnLiftedType (idType v)
+ && not (isTickBoxOp v)
exprOkForSpeculation (Note _ e) = exprOkForSpeculation e
exprOkForSpeculation (Cast e co) = exprOkForSpeculation e
exprOkForSpeculation other_expr
For unlifted argument types, we have to be careful:
C (f x :: Int#)
-Suppose (f x) diverges; then C (f x) is not a value. True, but
-this form is illegal (see the invariants in CoreSyn). Args of unboxed
+Suppose (f x) diverges; then C (f x) is not a value. However this can't
+happen: see CoreSyn Note [CoreSyn let/app invariant]. Args of unboxed
type must be ok-for-speculation (or trivial).
\begin{code}
-- A worry: what if an Id's unfolding is just itself:
-- then we could get an infinite loop...
-exprIsHNF (Lit l) = True
-exprIsHNF (Type ty) = True -- Types are honorary Values;
- -- we don't mind copying them
-exprIsHNF (Lam b e) = isRuntimeVar b || exprIsHNF e
-exprIsHNF (Note _ e) = exprIsHNF e
-exprIsHNF (Cast e co) = exprIsHNF e
+exprIsHNF (Lit l) = True
+exprIsHNF (Type ty) = True -- Types are honorary Values;
+ -- we don't mind copying them
+exprIsHNF (Lam b e) = isRuntimeVar b || exprIsHNF e
+exprIsHNF (Note _ e) = exprIsHNF e
+exprIsHNF (Cast e co) = exprIsHNF e
exprIsHNF (App e (Type _)) = exprIsHNF e
exprIsHNF (App e a) = app_is_value e [a]
-exprIsHNF other = False
+exprIsHNF other = False
-- There is at least one value argument
app_is_value (Var fun) args
- | isDataConWorkId fun -- Constructor apps are values
- || idArity fun > valArgCount args -- Under-applied function
- = check_args (idType fun) args
-app_is_value (App f a) as = app_is_value f (a:as)
-app_is_value other as = False
-
- -- 'check_args' checks that unlifted-type args
- -- are in fact guaranteed non-divergent
-check_args fun_ty [] = True
-check_args fun_ty (Type _ : args) = case splitForAllTy_maybe fun_ty of
- Just (_, ty) -> check_args ty args
-check_args fun_ty (arg : args)
- | isUnLiftedType arg_ty = exprOkForSpeculation arg
- | otherwise = check_args res_ty args
- where
- (arg_ty, res_ty) = splitFunTy fun_ty
+ = idArity fun > valArgCount args -- Under-applied function
+ || isDataConWorkId fun -- or data constructor
+app_is_value (Note n f) as = app_is_value f as
+app_is_value (Cast f _) as = app_is_value f as
+app_is_value (App f a) as = app_is_value f (a:as)
+app_is_value other as = False
\end{code}
\begin{code}
dataConRepFSInstPat = dataConInstPat dataConRepArgTys
dataConOrigInstPat = dataConInstPat dc_arg_tys (repeat (FSLIT("ipv")))
where
- dc_arg_tys dc = map mkPredTy (dataConTheta dc) ++ dataConOrigArgTys dc
+ dc_arg_tys dc = map mkPredTy (dataConEqTheta dc) ++ map mkPredTy (dataConDictTheta dc) ++ dataConOrigArgTys dc
-- Remember to include the existential dictionaries
dataConInstPat :: (DataCon -> [Type]) -- function used to find arg tys
--
-- co_tvs are intended to be used as binders for coercion args and the kinds
-- of these vars have been instantiated by the inst_tys and the ex_tys
+-- The co_tvs include both GADT equalities (dcEqSpec) and
+-- programmer-specified equalities (dcEqTheta)
--
--- arg_ids are indended to be used as binders for value arguments, including
--- dicts, and their types have been instantiated with inst_tys and ex_tys
+-- arg_ids are indended to be used as binders for value arguments,
+-- and their types have been instantiated with inst_tys and ex_tys
+-- The arg_ids include both dicts (dcDictTheta) and
+-- programmer-specified arguments (after rep-ing) (deRepArgTys)
--
-- Example.
-- The following constructor T1
-- where the double-primed variables are created with the FastStrings and
-- Uniques given as fss and us
dataConInstPat arg_fun fss uniqs con inst_tys
- = (ex_bndrs, co_bndrs, id_bndrs)
+ = (ex_bndrs, co_bndrs, arg_ids)
where
univ_tvs = dataConUnivTyVars con
ex_tvs = dataConExTyVars con
arg_tys = arg_fun con
eq_spec = dataConEqSpec con
- eq_preds = eqSpecPreds eq_spec
+ eq_theta = dataConEqTheta con
+ eq_preds = eqSpecPreds eq_spec ++ eq_theta
n_ex = length ex_tvs
- n_co = length eq_spec
+ n_co = length eq_preds
-- split the Uniques and FastStrings
(ex_uniqs, uniqs') = splitAt n_ex uniqs
co_kind = substTy subst (mkPredTy eq_pred)
-- make value vars, instantiating types
- mk_id_var uniq fs ty = mkUserLocal (mkVarOccFS fs) uniq (substTy subst ty) noSrcLoc
- id_bndrs = zipWith3 mk_id_var id_uniqs id_fss arg_tys
+ mk_id_var uniq fs ty = mkUserLocal (mkVarOccFS fs) uniq (substTy subst ty) noSrcSpan
+ arg_ids = zipWith3 mk_id_var id_uniqs id_fss arg_tys
exprIsConApp_maybe :: CoreExpr -> Maybe (DataCon, [CoreExpr])
-- Returns (Just (dc, [x1..xn])) if the argument expression is
-- The left-hand one must be a T, because exprIsConApp returned True
-- but the right-hand one might not be. (Though it usually will.)
- let (from_ty, to_ty) = coercionKind co
- (from_tc, _from_tc_arg_tys) = splitTyConApp from_ty
+ let (from_ty, to_ty) = coercionKind co
+ (from_tc, from_tc_arg_tys) = splitTyConApp from_ty
-- The inner one must be a TyConApp
in
- ASSERT( from_tc == dataConTyCon dc )
-
case splitTyConApp_maybe to_ty of {
Nothing -> Nothing ;
- Just (to_tc, _to_tc_arg_tys) | from_tc /= to_tc -> Nothing
- | otherwise ->
+ Just (to_tc, to_tc_arg_tys)
+ | from_tc /= to_tc -> Nothing
+ -- These two Nothing cases are possible; we might see
+ -- (C x y) `cast` (g :: T a ~ S [a]),
+ -- where S is a type function. In fact, exprIsConApp
+ -- will probably not be called in such circumstances,
+ -- but there't nothing wrong with it
+
+ | otherwise ->
let
tc_arity = tyConArity from_tc
in
ASSERT( length univ_args == tc_arity )
+ ASSERT( from_tc == dataConTyCon dc )
+ ASSERT( and (zipWith coreEqType [t | Type t <- univ_args] from_tc_arg_tys) )
ASSERT( all isTypeArg (univ_args ++ ex_args) )
ASSERT2( equalLength val_args arg_tys, ppr dc $$ ppr dc_tyvars $$ ppr dc_ex_tyvars $$ ppr arg_tys $$ ppr dc_args $$ ppr univ_args $$ ppr ex_args $$ ppr val_args $$ ppr arg_tys )
- Just (dc, univ_args ++ ex_args ++ new_co_args ++ new_val_args)
+ Just (dc, map Type to_tc_arg_tys ++ ex_args ++ new_co_args ++ new_val_args)
}}
+{-
+-- We do not want to tell the world that we have a
+-- Cons, to *stop* Case of Known Cons, which removes
+-- the TickBox.
+exprIsConApp_maybe (Note (TickBox {}) expr)
+ = Nothing
+exprIsConApp_maybe (Note (BinaryTickBox {}) expr)
+ = Nothing
+-}
+
exprIsConApp_maybe (Note _ expr)
= exprIsConApp_maybe expr
-- We ignore InlineMe notes in case we have
Lam lam_tv (eta_expand n us2 (App expr (Type (mkTyVarTy lam_tv))) (substTyWith [tv] [mkTyVarTy lam_tv] ty'))
where
- lam_tv = mkTyVar (mkSysTvName uniq FSLIT("etaT")) (tyVarKind tv)
+ lam_tv = setVarName tv (mkSysTvName uniq FSLIT("etaT"))
+ -- Using tv as a base retains its tyvar/covar-ness
(uniq:us2) = us
; Nothing ->
-- coerce T (\x::[T] -> (coerce ([T]->Int) e) x)
case splitNewTypeRepCo_maybe ty of {
- Just(ty1,co) ->
- mkCoerce (mkSymCoercion co) (eta_expand n us (mkCoerce co expr) ty1) ;
+ Just(ty1,co) -> mkCoerce (mkSymCoercion co)
+ (eta_expand n us (mkCoerce co expr) ty1) ;
Nothing ->
-- We have an expression of arity > 0, but its type isn't a function
exprIsBig (Var v) = False
exprIsBig (Type t) = False
exprIsBig (App f a) = exprIsBig f || exprIsBig a
+exprIsBig (Cast e _) = exprIsBig e -- Hopefully coercions are not too big!
exprIsBig other = True
\end{code}
noteSize (SCC cc) = cc `seq` 1
noteSize InlineMe = 1
noteSize (CoreNote s) = s `seq` 1 -- hdaume: core annotations
-
+
varSize :: Var -> Int
varSize b | isTyVar b = 1
| otherwise = seqType (idType b) `seq`
-- expressions may hash to the different Ints
--
-- The emphasis is on a crude, fast hash, rather than on high precision
-
-hashExpr e | hash < 0 = 77 -- Just in case we hit -maxInt
- | otherwise = hash
- where
- hash = abs (hash_expr e) -- Negative numbers kill UniqFM
-
-hash_expr (Note _ e) = hash_expr e
-hash_expr (Cast e co) = hash_expr e
-hash_expr (Let (NonRec b r) e) = hashId b
-hash_expr (Let (Rec ((b,r):_)) e) = hashId b
-hash_expr (Case _ b _ _) = hashId b
-hash_expr (App f e) = hash_expr f * fast_hash_expr e
-hash_expr (Var v) = hashId v
-hash_expr (Lit lit) = hashLiteral lit
-hash_expr (Lam b _) = hashId b
-hash_expr (Type t) = trace "hash_expr: type" 1 -- Shouldn't happen
-
-fast_hash_expr (Var v) = hashId v
-fast_hash_expr (Lit lit) = hashLiteral lit
-fast_hash_expr (App f (Type _)) = fast_hash_expr f
-fast_hash_expr (App f a) = fast_hash_expr a
-fast_hash_expr (Lam b _) = hashId b
-fast_hash_expr other = 1
-
-hashId :: Id -> Int
-hashId id = hashName (idName id)
+--
+-- We must be careful that \x.x and \y.y map to the same hash code,
+-- (at least if we want the above invariant to be true)
+
+hashExpr e = fromIntegral (hash_expr (1,emptyVarEnv) e .&. 0x7fffffff)
+ -- UniqFM doesn't like negative Ints
+
+type HashEnv = (Int, VarEnv Int) -- Hash code for bound variables
+
+hash_expr :: HashEnv -> CoreExpr -> Word32
+-- Word32, because we're expecting overflows here, and overflowing
+-- signed types just isn't cool. In C it's even undefined.
+hash_expr env (Note _ e) = hash_expr env e
+hash_expr env (Cast e co) = hash_expr env e
+hash_expr env (Var v) = hashVar env v
+hash_expr env (Lit lit) = fromIntegral (hashLiteral lit)
+hash_expr env (App f e) = hash_expr env f * fast_hash_expr env e
+hash_expr env (Let (NonRec b r) e) = hash_expr (extend_env env b) e * fast_hash_expr env r
+hash_expr env (Let (Rec ((b,r):_)) e) = hash_expr (extend_env env b) e
+hash_expr env (Case e _ _ _) = hash_expr env e
+hash_expr env (Lam b e) = hash_expr (extend_env env b) e
+hash_expr env (Type t) = WARN(True, text "hash_expr: type") 1
+-- Shouldn't happen. Better to use WARN than trace, because trace
+-- prevents the CPR optimisation kicking in for hash_expr.
+
+fast_hash_expr env (Var v) = hashVar env v
+fast_hash_expr env (Type t) = fast_hash_type env t
+fast_hash_expr env (Lit lit) = fromIntegral (hashLiteral lit)
+fast_hash_expr env (Cast e co) = fast_hash_expr env e
+fast_hash_expr env (Note n e) = fast_hash_expr env e
+fast_hash_expr env (App f a) = fast_hash_expr env a -- A bit idiosyncratic ('a' not 'f')!
+fast_hash_expr env other = 1
+
+fast_hash_type :: HashEnv -> Type -> Word32
+fast_hash_type env ty
+ | Just tv <- getTyVar_maybe ty = hashVar env tv
+ | Just (tc,tys) <- splitTyConApp_maybe ty = let hash_tc = fromIntegral (hashName (tyConName tc))
+ in foldr (\t n -> fast_hash_type env t + n) hash_tc tys
+ | otherwise = 1
+
+extend_env :: HashEnv -> Var -> (Int, VarEnv Int)
+extend_env (n,env) b = (n+1, extendVarEnv env b n)
+
+hashVar :: HashEnv -> Var -> Word32
+hashVar (_,env) v
+ = fromIntegral (lookupVarEnv env v `orElse` hashName (idName v))
\end{code}
%************************************************************************
projects / ghc-hetmet.git / blobdiff