From 65284c9655167101ad716863bc8db5cc8ad76a2b Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Wed, 7 Jul 1999 15:27:27 +0000
Subject: [PATCH] [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 | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/ghc/compiler/coreSyn/CoreUnfold.lhs b/ghc/compiler/coreSyn/CoreUnfold.lhs
index f27289ec0e92..0c8e6e1414d7 100644
--- a/ghc/compiler/coreSyn/CoreUnfold.lhs
+++ b/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`
--
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