%
-% (c) The University of Glasgow, 1994-2000
+% (c) The University of Glasgow, 1994-2006
%
-\section{Core pass to saturate constructors and PrimOps}
+
+Core pass to saturate constructors and PrimOps
\begin{code}
module CorePrep (
#include "HsVersions.h"
-import CoreUtils( exprType, exprIsHNF, etaExpand, exprArity, exprOkForSpeculation )
-import CoreFVs ( exprFreeVars )
-import CoreLint ( endPass )
+import CoreUtils hiding (exprIsTrivial)
+import CoreFVs
+import CoreLint
import CoreSyn
-import Type ( Type, applyTy,
- splitFunTy_maybe, isUnLiftedType, isUnboxedTupleType, seqType )
-import Coercion ( coercionKind )
-import TyCon ( TyCon, tyConDataCons )
-import NewDemand ( Demand, isStrictDmd, lazyDmd, StrictSig(..), DmdType(..) )
-import Var ( Var, Id, setVarUnique )
+import Type
+import Coercion
+import TyCon
+import NewDemand
+import Var
import VarSet
import VarEnv
-import Id ( mkSysLocal, idType, idNewDemandInfo, idArity, setIdUnfolding,
- isFCallId, isGlobalId, isLocalId, hasNoBinding, idNewStrictness,
- isPrimOpId_maybe
- )
-import DataCon ( dataConWorkId )
-import PrimOp ( PrimOp( DataToTagOp ) )
-import BasicTypes ( TopLevelFlag(..), isTopLevel, isNotTopLevel,
- RecFlag(..), isNonRec
- )
+import Id
+import IdInfo
+import DataCon
+import PrimOp
+import BasicTypes
import UniqSupply
import Maybes
import OrdList
import ErrUtils
import DynFlags
-import Util ( listLengthCmp )
+import Util
import Outputable
+import TysWiredIn
+import MkId
+import TysPrim
\end{code}
-- ---------------------------------------------------------------------------
deLamFloat expr1 `thenUs` \ (floats, expr2) ->
returnUs (floats, Note n expr2)
+corePrepExprFloat env (Case (Var id) bndr ty [(DEFAULT,[],expr)])
+ | Just (TickBox {}) <- isTickBoxOp_maybe id
+ = corePrepAnExpr env expr `thenUs` \ expr1 ->
+ deLamFloat expr1 `thenUs` \ (floats, expr2) ->
+ return (floats, Case (Var id) bndr ty [(DEFAULT,[],expr2)])
+
+-- Translate Binary tickBox into standard tickBox
+corePrepExprFloat env (App (Var id) expr)
+ | Just (BinaryTickBox m t e) <- isTickBoxOp_maybe id
+ = corePrepAnExpr env expr `thenUs` \ expr1 ->
+ deLamFloat expr1 `thenUs` \ (floats, expr2) ->
+ getUniqueUs `thenUs` \ u1 ->
+ getUniqueUs `thenUs` \ u2 ->
+ getUniqueUs `thenUs` \ u3 ->
+ getUniqueUs `thenUs` \ u4 ->
+ getUniqueUs `thenUs` \ u5 ->
+ let bndr1 = mkSysLocal FSLIT("t1") u1 boolTy in
+ let bndr2 = mkSysLocal FSLIT("t2") u2 realWorldStatePrimTy in
+ let bndr3 = mkSysLocal FSLIT("t3") u3 realWorldStatePrimTy in
+ let tick_e = mkTickBoxOpId u4 m e in
+ let tick_t = mkTickBoxOpId u5 m t in
+ return (floats, Case expr2
+ bndr1
+ boolTy
+ [ (DataAlt falseDataCon, [],
+ Case (Var tick_e) bndr2 boolTy [(DEFAULT,[],Var falseDataConId)])
+ , (DataAlt trueDataCon, [],
+ Case (Var tick_t) bndr3 boolTy [(DEFAULT,[],Var trueDataConId)])
+ ])
+
corePrepExprFloat env (Note other_note expr)
= corePrepExprFloat env expr `thenUs` \ (floats, expr') ->
returnUs (floats, Note other_note expr')
where
(bndrs,body) = collectBinders expr
+-- This is an (important) optimization.
+-- case <btick,A,B> e of { T -> e1 ; F -> e2 }
+-- ==> case e of { T -> <tick,A> e1 ; F -> <tick,B> e2 }
+-- This could move into the simplifier.
+
+corePrepExprFloat env (Case (App (Var id) expr) bndr ty alts)
+ | Just (BinaryTickBox m t e) <- isTickBoxOp_maybe id
+ = getUniqueUs `thenUs` \ u1 ->
+ getUniqueUs `thenUs` \ u2 ->
+ getUniqueUs `thenUs` \ u3 ->
+ getUniqueUs `thenUs` \ u4 ->
+ getUniqueUs `thenUs` \ u5 ->
+ let bndr1 = mkSysLocal FSLIT("t1") u1 boolTy in
+ let bndr2 = mkSysLocal FSLIT("t2") u2 realWorldStatePrimTy in
+ let bndr3 = mkSysLocal FSLIT("t3") u3 realWorldStatePrimTy in
+ let tick_e = mkTickBoxOpId u4 m e in
+ let tick_t = mkTickBoxOpId u5 m t in
+ ASSERT (exprType expr `coreEqType` boolTy)
+ corePrepExprFloat env $
+ Case expr
+ bndr1
+ ty
+ [ (DataAlt falseDataCon, [],
+ Case (Var tick_e) bndr2 ty [(DEFAULT,[],falseBranch)])
+ , (DataAlt trueDataCon, [],
+ Case (Var tick_t) bndr3 ty [(DEFAULT,[],trueBranch)])
+ ]
+
+ where
+ (_,_,trueBranch) = findAlt (DataAlt trueDataCon) alts
+ (_,_,falseBranch) = findAlt (DataAlt falseDataCon) alts
+
corePrepExprFloat env (Case scrut bndr ty alts)
= corePrepExprFloat env scrut `thenUs` \ (floats1, scrut1) ->
deLamFloat scrut1 `thenUs` \ (floats2, scrut2) ->