X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FcoreSyn%2FCoreSyn.lhs;h=e580bed20c0a78d024a90915db2b5b09a2d429b6;hp=c2e3aba487c9d06b14980eb456e5164110dcc765;hb=8100cd4395e46ae747be4298c181a4730d6206bc;hpb=14d5afa72e8e86db95bd1c01d906b80b444e8d29

diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs
index c2e3aba..e580bed 100644
--- a/compiler/coreSyn/CoreSyn.lhs
+++ b/compiler/coreSyn/CoreSyn.lhs
@@ -1,7 +1,9 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-\section[CoreSyn]{A data type for the Haskell compiler midsection}
+
+CoreSyn: A data type for the Haskell compiler midsection
 
 \begin{code}
 module CoreSyn (
@@ -12,8 +14,8 @@ module CoreSyn (
 	mkLets, mkLams, 
 	mkApps, mkTyApps, mkValApps, mkVarApps,
 	mkLit, mkIntLitInt, mkIntLit, 
-	mkConApp, 
-	varToCoreExpr,
+	mkConApp, mkCast,
+	varToCoreExpr, varsToCoreExprs,
 
 	isTyVar, isId, cmpAltCon, cmpAlt, ltAlt,
 	bindersOf, bindersOfBinds, rhssOfBind, rhssOfAlts, 
@@ -40,21 +42,22 @@ module CoreSyn (
 
 	-- Core rules
 	CoreRule(..),	-- CoreSubst, CoreTidy, CoreFVs, PprCore only
-	RuleName, seqRules, 
+	RuleName, seqRules, ruleArity,
 	isBuiltinRule, ruleName, isLocalRule, ruleIdName
     ) where
 
 #include "HsVersions.h"
 
-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 StaticFlags
+import CostCentre
+import Var
+import Type
+import Coercion
+import Name
+import OccName
+import Literal
+import DataCon
+import BasicTypes
 import FastString
 import Outputable
 
@@ -90,6 +93,7 @@ data Expr b	-- "b" for the type of binders,
 	--		lit	(for LitAlts)
 	--	      This makes finding the relevant constructor easy,
 	--	      and makes comparison easier too
+  | Cast  (Expr b) Coercion
   | Note  Note (Expr b)
   | Type  Type			-- This should only show up at the top
 				-- level of an Arg
@@ -110,7 +114,8 @@ 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
+data AltCon = DataAlt DataCon	-- Invariant: the DataCon is always from 
+				-- a *data* type, and never from a *newtype*
 	    | LitAlt  Literal
 	    | DEFAULT
 	 deriving (Eq, Ord)
@@ -122,10 +127,6 @@ data Bind b = NonRec 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
-
   | InlineMe		-- Instructs simplifer to treat the enclosed expression
 			-- as very small, and inline it at its call sites
 
@@ -202,18 +203,23 @@ data CoreRule
 	ru_local :: Bool,	-- The fn at the head of the rule is
 				-- defined in the same module as the rule
 
-	-- Orphan-hood; see comments is InstEnv.Instance( is_orph )
+	-- Orphan-hood; see Note [Orphans] in InstEnv
 	ru_orph  :: Maybe OccName }
 
   | 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_nargs :: Int,	-- Number of args that ru_try expects
 	ru_try  :: [CoreExpr] -> Maybe CoreExpr }
 
 isBuiltinRule (BuiltinRule {}) = True
 isBuiltinRule _		       = False
 
+ruleArity :: CoreRule -> Int
+ruleArity (BuiltinRule {ru_nargs = n}) = n
+ruleArity (Rule {ru_args = args})      = length args
+
 ruleName :: CoreRule -> RuleName
 ruleName = ru_name
 
@@ -452,6 +458,12 @@ mkIntLitInt n = Lit (mkMachInt (toInteger n))
 varToCoreExpr :: CoreBndr -> Expr b
 varToCoreExpr v | isId v    = Var v
                 | otherwise = Type (mkTyVarTy v)
+
+varsToCoreExprs :: [CoreBndr] -> [Expr b]
+varsToCoreExprs vs = map varToCoreExpr vs
+
+mkCast   :: Expr b -> Coercion -> Expr b
+mkCast e co = Cast e co
 \end{code}
 
 
@@ -599,15 +611,14 @@ 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 (Cast e co)     = seqExpr e `seq` seqType co
 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	       = ()
 
@@ -647,9 +658,9 @@ data AnnExpr' bndr annot
   | 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)
+  | AnnCast     (AnnExpr bndr annot) Coercion
   | AnnNote	Note (AnnExpr bndr annot)
   | AnnType	Type
 
@@ -669,6 +680,7 @@ 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' (AnnNote note body)   = Note note (deAnnotate body)
 
 deAnnotate' (AnnLet bind body)
@@ -677,7 +689,6 @@ deAnnotate' (AnnLet bind body)
     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)