Tweak alternative layout rule

[ghc-hetmet.git] / compiler / coreSyn / CoreUnfold.lhs

diff --git a/compiler/coreSyn/CoreUnfold.lhs b/compiler/coreSyn/CoreUnfold.lhs
index f83521c..fd76f23 100644 (file)
--- a/compiler/coreSyn/CoreUnfold.lhs
+++ b/compiler/coreSyn/CoreUnfold.lhs
@@ -319,9 +319,13 @@ sizeExpr bOMB_OUT_SIZE top_args expr
           _                -> funSize top_args fun (length val_args)
 
     ------------ 
-    size_up_alt (_con, _bndrs, rhs) = size_up rhs
+    size_up_alt (_con, _bndrs, rhs) = size_up rhs `addSizeN` 1
        -- Don't charge for args, so that wrappers look cheap
        -- (See comments about wrappers with Case)
+       --
+       -- IMPORATANT: *do* charge 1 for the alternative, else we 
+       -- find that giant case nests are treated as practically free
+       -- A good example is Foreign.C.Error.errrnoToIOError
 
     ------------
        -- These addSize things have to be here because
@@ -629,10 +633,7 @@ instance Outputable CallCtxt where
   ppr ValAppCtxt      = ptext (sLit "ValAppCtxt")
 
 callSiteInline dflags active_inline id lone_variable arg_infos cont_info
-  = let
-       n_val_args  = length arg_infos
-    in
-    case idUnfolding id of {
+  = case idUnfolding id of {
        NoUnfolding      -> Nothing ;
        OtherCon _       -> Nothing ;
        DFunUnfolding {} -> Nothing ;   -- Never unfold a DFun
@@ -641,6 +642,8 @@ callSiteInline dflags active_inline id lone_variable arg_infos cont_info
                        -- uf_arity will typically be equal to (idArity id), 
                        -- but may be less for InlineRules
     let
+       n_val_args  = length arg_infos
+
        result | yes_or_no = Just unf_template
               | otherwise = Nothing
 
@@ -1128,7 +1131,9 @@ exprIsConApp_maybe expr
                       analyse rhs args
         where
          is_saturated = count isValArg args == idArity fun
-          unfolding = idUnfolding fun
+          unfolding = idUnfolding fun    -- Does not look through loop breakers
+                   -- ToDo: we *may* look through variables that are NOINLINE
+                   --       in this phase, and that is really not right
 
     analyse _ _ = Nothing