%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[DsBinds]{Pattern-matching bindings (HsBinds and MonoBinds)}
lower levels it is preserved with @let@/@letrec@s).
\begin{code}
+module DsBinds ( dsMonoBinds, AutoScc(..) ) where
+
#include "HsVersions.h"
-module DsBinds ( dsBinds, dsMonoBinds ) where
-IMP_Ubiq()
-IMPORT_DELOOPER(DsLoop) -- break dsExpr-ish loop
+import {-# SOURCE #-} DsExpr( dsExpr )
import HsSyn -- lots of things
import CoreSyn -- lots of things
import CoreUtils ( coreExprType )
-import TcHsSyn ( SYN_IE(TypecheckedHsBinds), SYN_IE(TypecheckedHsExpr),
- SYN_IE(TypecheckedMonoBinds),
- SYN_IE(TypecheckedPat)
- )
+import TcHsSyn ( TypecheckedMonoBinds )
import DsMonad
import DsGRHSs ( dsGuarded )
import DsUtils
import Match ( matchWrapper )
+import BasicTypes ( RecFlag(..) )
import CmdLineOpts ( opt_SccProfilingOn, opt_AutoSccsOnAllToplevs,
- opt_AutoSccsOnExportedToplevs, opt_CompilingGhcInternals )
-import CostCentre ( mkAutoCC, IsCafCC(..), mkAllDictsCC, preludeDictsCostCentre )
-import Id ( idType, SYN_IE(DictVar), GenId, SYN_IE(Id) )
-import ListSetOps ( minusList, intersectLists )
+ opt_AutoSccsOnExportedToplevs, opt_AutoSccsOnDicts
+ )
+import CostCentre ( CostCentre, mkAutoCC, IsCafCC(..) )
+import Id ( idType, Id )
+import VarEnv
import Name ( isExported )
-import PprType ( GenType )
-import PprStyle ( PprStyle(..) )
-import Type ( mkTyVarTy, isDictTy, instantiateTy
- )
-import TyVar ( tyVarSetToList, GenTyVar{-instance Eq-} )
-import TysPrim ( voidTy )
-import Util ( isIn, panic{-, pprTrace ToDo:rm-} )
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[toplevel-and-regular-DsBinds]{Regular and top-level @dsBinds@}
-%* *
-%************************************************************************
+import Type ( mkTyVarTy, isDictTy, substTy )
+import TysWiredIn ( voidTy )
+import Outputable
-Like @dsBinds@, @dsBind@ returns a @[CoreBinding]@, but it may be
-that some of the binders are of unboxed type. This is sorted out when
-the caller wraps the bindings round an expression.
-
-\begin{code}
-dsBinds :: TypecheckedHsBinds -> DsM [CoreBinding]
-
-dsBinds EmptyBinds = returnDs []
-dsBinds (ThenBinds binds_1 binds_2) = andDs (++) (dsBinds binds_1) (dsBinds binds_2)
-
-dsBinds (MonoBind binds sigs is_rec)
- = dsMonoBinds is_rec binds `thenDs` \ prs ->
- returnDs (if is_rec then
- [Rec prs]
- else
- [NonRec binder rhs | (binder,rhs) <- prs]
- )
+import Maybe
+import IOExts (trace)
\end{code}
-
%************************************************************************
%* *
\subsection[dsMonoBinds]{Desugaring a @MonoBinds@}
%************************************************************************
\begin{code}
-dsMonoBinds :: RecFlag -> TypecheckedMonoBinds -> DsM [(Id,CoreExpr)]
+dsMonoBinds :: AutoScc -- scc annotation policy (see below)
+ -> TypecheckedMonoBinds
+ -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
+ -> DsM [(Id,CoreExpr)] -- Result
-dsMonoBinds is_rec EmptyMonoBinds = returnDs []
+dsMonoBinds _ EmptyMonoBinds rest = returnDs rest
-dsMonoBinds is_rec (AndMonoBinds binds_1 binds_2)
- = andDs (++) (dsMonoBinds is_rec binds_1) (dsMonoBinds is_rec binds_2)
+dsMonoBinds auto_scc (AndMonoBinds binds_1 binds_2) rest
+ = dsMonoBinds auto_scc binds_2 rest `thenDs` \ rest' ->
+ dsMonoBinds auto_scc binds_1 rest'
-dsMonoBinds is_rec (CoreMonoBind var core_expr)
- = returnDs [(var, core_expr)]
+dsMonoBinds _ (CoreMonoBind var core_expr) rest
+ = returnDs ((var, core_expr) : rest)
-dsMonoBinds is_rec (VarMonoBind var expr)
+dsMonoBinds _ (VarMonoBind var expr) rest
= dsExpr expr `thenDs` \ core_expr ->
-- Dictionary bindings are always VarMonoBinds, so
-- we only need do this here
addDictScc var core_expr `thenDs` \ core_expr' ->
- returnDs [(var, core_expr')]
+ returnDs ((var, core_expr') : rest)
-dsMonoBinds is_rec (FunMonoBind fun _ matches locn)
+dsMonoBinds auto_scc (FunMonoBind fun _ matches locn) rest
= putSrcLocDs locn $
matchWrapper (FunMatch fun) matches error_string `thenDs` \ (args, body) ->
- returnDs [(fun, mkValLam args body)]
+ addAutoScc auto_scc (fun, mkLams args body) `thenDs` \ pair ->
+ returnDs (pair : rest)
where
- error_string = "function " ++ showForErr fun
+ error_string = "function " ++ showSDoc (ppr fun)
-dsMonoBinds is_rec (PatMonoBind pat grhss_and_binds locn)
+dsMonoBinds auto_scc (PatMonoBind pat grhss locn) rest
= putSrcLocDs locn $
- dsGuarded grhss_and_binds `thenDs` \ body_expr ->
- mkSelectorBinds pat body_expr
+ dsGuarded grhss `thenDs` \ body_expr ->
+ mkSelectorBinds pat body_expr `thenDs` \ sel_binds ->
+ mapDs (addAutoScc auto_scc) sel_binds `thenDs` \ sel_binds ->
+ returnDs (sel_binds ++ rest)
+
+ -- Common case: one exported variable
+ -- All non-recursive bindings come through this way
+dsMonoBinds auto_scc (AbsBinds all_tyvars dicts exps@[(tyvars, global, local)] binds) rest
+ = ASSERT( all (`elem` tyvars) all_tyvars )
+ dsMonoBinds (addSccs auto_scc exps) binds [] `thenDs` \ core_prs ->
+ let
+ -- Always treat the binds as recursive, because the typechecker
+ -- makes rather mixed-up dictionary bindings
+ core_binds = [Rec core_prs]
+ global' = (global, mkLams tyvars $ mkLams dicts $
+ mkLets core_binds (Var local))
+ in
+
+ returnDs (global' : rest)
-dsMonoBinds is_rec (AbsBinds [] [] exports binds) -- Common special case
- = dsMonoBinds is_rec binds `thenDs` \ prs ->
- returnDs (prs ++ [(global, Var local) | (_, global, local) <- exports])
+ -- Another Common special case: no type or dictionary abstraction
+dsMonoBinds auto_scc (AbsBinds [] [] exports binds) rest
+ = let exports' = [(global, Var local) | (_, global, local) <- exports] in
+ dsMonoBinds (addSccs auto_scc exports) binds (exports' ++ rest)
-dsMonoBinds is_rec (AbsBinds all_tyvars dicts exports binds)
- = dsMonoBinds is_rec binds `thenDs` \ core_prs ->
+dsMonoBinds auto_scc (AbsBinds all_tyvars dicts exports binds) rest
+ = dsMonoBinds (addSccs auto_scc exports) binds []`thenDs` \ core_prs ->
let
- core_binds | is_rec = [Rec core_prs]
- | otherwise = [NonRec b e | (b,e) <- core_prs]
-
- tup_expr = mkLam all_tyvars dicts $
- mkCoLetsAny core_binds $
- mkTupleExpr locals
- locals = [local | (_, _, local) <- exports]
- local_tys = map idType locals
+ core_binds = [Rec core_prs]
+
+ tup_expr = mkTupleExpr locals
+ tup_ty = coreExprType tup_expr
+ poly_tup_expr = mkLams all_tyvars $ mkLams dicts $
+ mkLets core_binds tup_expr
+ locals = [local | (_, _, local) <- exports]
+ local_tys = map idType locals
in
- newSysLocalDs (coreExprType tup_expr) `thenDs` \ tup_id ->
+ newSysLocalDs (coreExprType poly_tup_expr) `thenDs` \ poly_tup_id ->
let
- dict_args = map VarArg dicts
+ dict_args = map Var dicts
mk_bind (tyvars, global, local) n -- locals !! n == local
= -- Need to make fresh locals to bind in the selector, because
-- some of the tyvars will be bound to voidTy
- newSysLocalsDs (map (instantiateTy env) local_tys) `thenDs` \ locals' ->
- returnDs (global, mkLam tyvars dicts $
- mkTupleSelector locals' (locals' !! n) $
- mkValApp (mkTyApp (Var tup_id) ty_args) dict_args)
+ newSysLocalsDs (map (substTy env) local_tys) `thenDs` \ locals' ->
+ newSysLocalDs (substTy env tup_ty) `thenDs` \ tup_id ->
+ returnDs (global, mkLams tyvars $ mkLams dicts $
+ mkTupleSelector locals' (locals' !! n) tup_id $
+ mkApps (mkTyApps (Var poly_tup_id) ty_args) dict_args)
where
mk_ty_arg all_tyvar | all_tyvar `elem` tyvars = mkTyVarTy all_tyvar
| otherwise = voidTy
ty_args = map mk_ty_arg all_tyvars
- env = all_tyvars `zip` ty_args
+ env = all_tyvars `zipVarEnv` ty_args
in
zipWithDs mk_bind exports [0..] `thenDs` \ export_binds ->
- returnDs ((tup_id, tup_expr) : export_binds)
+ -- don't scc (auto-)annotate the tuple itself.
+ returnDs ((poly_tup_id, poly_tup_expr) : (export_binds ++ rest))
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection[addAutoScc]{Adding automatic sccs}
+%* *
+%************************************************************************
+
+\begin{code}
+data AutoScc
+ = TopLevel
+ | TopLevelAddSccs (Id -> Maybe Id)
+ | NoSccs
+
+addSccs :: AutoScc -> [(a,Id,Id)] -> AutoScc
+addSccs auto_scc@(TopLevelAddSccs _) exports = auto_scc
+addSccs NoSccs exports = NoSccs
+addSccs TopLevel exports
+ = TopLevelAddSccs (\id -> case [ exp | (_,exp,loc) <- exports, loc == id ] of
+ (exp:_) | opt_AutoSccsOnAllToplevs ||
+ (isExported exp &&
+ opt_AutoSccsOnExportedToplevs)
+ -> Just exp
+ _ -> Nothing)
+
+addAutoScc :: AutoScc -- if needs be, decorate toplevs?
+ -> (Id, CoreExpr)
+ -> DsM (Id, CoreExpr)
+
+addAutoScc (TopLevelAddSccs auto_scc_fn) pair@(bndr, core_expr)
+ | do_auto_scc && worthSCC core_expr
+ = getModuleAndGroupDs `thenDs` \ (mod,grp) ->
+ returnDs (bndr, Note (SCC (mkAutoCC top_bndr mod grp NotCafCC)) core_expr)
+ where do_auto_scc = isJust maybe_auto_scc
+ maybe_auto_scc = auto_scc_fn bndr
+ (Just top_bndr) = maybe_auto_scc
+addAutoScc _ pair
+ = returnDs pair
+
+worthSCC (Note (SCC _) _) = False
+worthSCC (Con _ _) = False
+worthSCC core_expr = True
\end{code}
If profiling and dealing with a dict binding, wrap the dict in "_scc_ DICT <dict>":
\begin{code}
-addDictScc var rhs
- | not ( opt_SccProfilingOn || opt_AutoSccsOnAllToplevs)
- -- the latter is so that -unprof-auto-scc-all adds dict sccs
+addDictScc var rhs = returnDs rhs
+
+{- DISABLED for now (need to somehow make up a name for the scc) -- SDM
+ | not ( opt_SccProfilingOn && opt_AutoSccsOnDicts)
|| not (isDictTy (idType var))
= returnDs rhs -- That's easy: do nothing
- | opt_CompilingGhcInternals
- = returnDs (SCC prel_dicts_cc rhs)
-
| otherwise
= getModuleAndGroupDs `thenDs` \ (mod, grp) ->
-
-- ToDo: do -dicts-all flag (mark dict things with individual CCs)
- returnDs (SCC (mkAllDictsCC mod grp False) rhs)
-
-prel_dicts_cc = preludeDictsCostCentre False{-not dupd-} -- ditto
+ returnDs (Note (SCC (mkAllDictsCC mod grp False)) rhs)
+-}
\end{code}