Improve RULE matching a bit more

[ghc-hetmet.git] / compiler / basicTypes / MkId.lhs

diff --git a/compiler/basicTypes/MkId.lhs b/compiler/basicTypes/MkId.lhs
index 84b3546..0c84685 100644 (file)
--- a/compiler/basicTypes/MkId.lhs
+++ b/compiler/basicTypes/MkId.lhs
@@ -252,7 +252,7 @@ mkDataConIds wrap_name wkr_name data_con
                           isSingleton orig_arg_tys )
                   -- No existentials on a newtype, but it can have a context
                   -- e.g.      newtype Eq a => T a = MkT (...)
-                  mkTopUnfolding $ Note InlineMe $
+                  mkCompulsoryUnfolding $ 
                   mkLams tyvars $ Lam id_arg1 $ 
                   mkNewTypeBody tycon result_ty (Var id_arg1)
 
@@ -902,22 +902,26 @@ seqId
     ty  = mkForAllTys [alphaTyVar,openBetaTyVar]
                      (mkFunTy alphaTy (mkFunTy openBetaTy openBetaTy))
     [x,y] = mkTemplateLocals [alphaTy, openBetaTy]
--- gaw 2004
     rhs = mkLams [alphaTyVar,openBetaTyVar,x,y] (Case (Var x) x openBetaTy [(DEFAULT, [], Var y)])
 
 -- lazy :: forall a?. a? -> a?  (i.e. works for unboxed types too)
 -- Used to lazify pseq:                pseq a b = a `seq` lazy b
--- No unfolding: it gets "inlined" by the worker/wrapper pass
--- Also, no strictness: by being a built-in Id, it overrides all
--- the info in PrelBase.hi.  This is important, because the strictness
+-- 
+-- Also, no strictness: by being a built-in Id, all the info about lazyId comes from here,
+-- not from GHC.Base.hi.   This is important, because the strictness
 -- analyser will spot it as strict!
+--
+-- Also no unfolding in lazyId: it gets "inlined" by a HACK in the worker/wrapper pass
+--     (see WorkWrap.wwExpr)   
+-- We could use inline phases to do this, but that would be vulnerable to changes in 
+-- phase numbering....we must inline precisely after strictness analysis.
 lazyId
   = pcMiscPrelId lazyIdName ty info
   where
     info = noCafIdInfo
     ty  = mkForAllTys [alphaTyVar] (mkFunTy alphaTy alphaTy)
 
-lazyIdUnfolding :: CoreExpr    -- Used to expand LazyOp after strictness anal
+lazyIdUnfolding :: CoreExpr    -- Used to expand 'lazyId' after strictness anal
 lazyIdUnfolding = mkLams [openAlphaTyVar,x] (Var x)
                where
                  [x] = mkTemplateLocals [openAlphaTy]