[project @ 1999-07-07 15:27:27 by simonmar]

- charge 1 for a case expression

- give a discount of opt_UF_ScrutConDiscount each time a constructor
  is scrutinised

(previously a case expression was not charged for at all, and the
discount for a scrutinised constructor was (opt_UF_ScrutConDiscount *
tyconFamilySize).  In 4.02, a case expression was also charged
tyconFamilySize to balance the discount, but this had the disadvantage
of charging for alternatives which may not be present in the actual
case expression).

ghc/compiler/coreSyn/CoreUnfold.lhs

@@ -205,7 +205,7 @@ calcUnfoldingGuidance bOMB_OUT_SIZE expr
 	    discount_for b 
 		| num_cases == 0 = 0
 		| is_fun_ty  	 = num_cases * opt_UF_FunAppDiscount
-		| is_data_ty 	 = num_cases * tyConFamilySize tycon * opt_UF_ScrutConDiscount
+		| is_data_ty 	 = num_cases * opt_UF_ScrutConDiscount
 		| otherwise  	 = num_cases * opt_UF_PrimArgDiscount
 		where
 		  num_cases	      = foldlBag (\n b' -> if b==b' then n+1 else n) 0 cased_args
@@ -267,6 +267,7 @@ sizeExpr (I# bOMB_OUT_SIZE) args expr
       = nukeScrutDiscount (size_up scrut)		`addSize`
 	arg_discount scrut				`addSize`
 	foldr (addSize . size_up_alt) sizeZero alts	
+	  `addSizeN` 1  -- charge one for the case itself.
 
 -- Just charge for the alts that exist, not the ones that might exist
 --	`addSizeN`