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authorsimonpj@microsoft.com <unknown>2006-11-10 13:10:36 +0000
committersimonpj@microsoft.com <unknown>2006-11-10 13:10:36 +0000
commita515009d89b62d6bc4fc34844db37edb5d4ef6ac (patch)
tree1e0fb9fb7258b77066e8835d2cf054c90f6a67a3 /compiler/stranal
parent308cb59e89a5be1ed6d55da39a843ca5f1828445 (diff)
downloadhaskell-a515009d89b62d6bc4fc34844db37edb5d4ef6ac.tar.gz
Comments and cosmetics only
Diffstat (limited to 'compiler/stranal')
-rw-r--r--compiler/stranal/DmdAnal.lhs13
1 files changed, 9 insertions, 4 deletions
diff --git a/compiler/stranal/DmdAnal.lhs b/compiler/stranal/DmdAnal.lhs
index 309cd29705..4c5de9616f 100644
--- a/compiler/stranal/DmdAnal.lhs
+++ b/compiler/stranal/DmdAnal.lhs
@@ -262,8 +262,8 @@ dmdAnal sigs dmd (Case scrut case_bndr ty [alt@(DataAlt dc,bndrs,rhs)])
-- The insight is, of course, that a demand on y is a demand on the
-- scrutinee, so we need to `both` it with the scrut demand
- scrut_dmd = Eval (Prod [idNewDemandInfo b | b <- bndrs', isId b])
- `both`
+ alt_dmd = Eval (Prod [idNewDemandInfo b | b <- bndrs', isId b])
+ scrut_dmd = alt_dmd `both`
idNewDemandInfo case_bndr'
(scrut_ty, scrut') = dmdAnal sigs scrut_dmd scrut
@@ -489,7 +489,12 @@ If we marked r as having the CPR property, then we'd w/w into
in ...
But now r is a thunk, which won't be inlined, so we are no further ahead.
+But consider
+ f x = let r = case expensive of (a,b) -> (b,a)
+ in if foo r then r else (x,x)
+
+Does f have the CPR property? Well, no.
However, if the strictness analyser has figured out (in a previous
iteration) that it's strict, then we DON'T need to forget the CPR info.
@@ -986,7 +991,7 @@ lub d1@(Eval _) d2 = d2 `lub` d1 -- Bot,Abs,Top,Call,Defer
lub (Box d1) (Box d2) = box (d1 `lub` d2)
lub d1@(Box _) d2 = d2 `lub` d1
-lubs = zipWithDmds lub
+lubs ds1 ds2 = zipWithDmds lub ds1 ds2
---------------------
-- box is the smart constructor for Box
@@ -1093,7 +1098,7 @@ both d1@(Eval ds1) d2 = d2 `both` d1
both (Defer ds1) (Defer ds2) = deferEval (ds1 `boths` ds2)
both d1@(Defer ds1) d2 = d2 `both` d1
-boths = zipWithDmds both
+boths ds1 ds2 = zipWithDmds both ds1 ds2
\end{code}