X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FIdInfo.lhs;h=3e64ee562627c7efdc643532e236c1c2d4cb6bd1;hb=727fae32ea0b6ca6ebdf1b3137649813e4d7ac3d;hp=c1a69b28690f387999d4cd843cac51d6a625b14e;hpb=ad94d40948668032189ad22a0ad741ac1f645f50;p=ghc-hetmet.git

diff --git a/compiler/basicTypes/IdInfo.lhs b/compiler/basicTypes/IdInfo.lhs
index c1a69b2..3e64ee5 100644
--- a/compiler/basicTypes/IdInfo.lhs
+++ b/compiler/basicTypes/IdInfo.lhs
@@ -12,7 +12,7 @@ Haskell. [WDP 94/11])
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
 -- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
 module IdInfo (
@@ -72,7 +72,7 @@ module IdInfo (
 
 	-- Specialisation
 	SpecInfo(..), specInfo, setSpecInfo, isEmptySpecInfo, 
-	specInfoFreeVars, specInfoRules, seqSpecInfo,
+	specInfoFreeVars, specInfoRules, seqSpecInfo, setSpecInfoHead,
 
 	-- CAF info
 	CafInfo(..), cafInfo, ppCafInfo, setCafInfo, mayHaveCafRefs,
@@ -89,6 +89,7 @@ module IdInfo (
 import CoreSyn
 import Class
 import PrimOp
+import Name
 import Var
 import VarSet
 import BasicTypes
@@ -102,7 +103,6 @@ import Module
 import Data.Maybe
 
 #ifdef OLD_STRICTNESS
-import Name
 import Demand
 import qualified Demand
 import Util
@@ -474,8 +474,10 @@ type InlinePragInfo = Activation
 data SpecInfo 
   = SpecInfo 
 	[CoreRule] 
-	VarSet		-- Locally-defined free vars of *both* LHS and RHS of rules
-			-- Note [Rule dependency info]
+	VarSet		-- Locally-defined free vars of *both* LHS and RHS 
+			-- of rules.  I don't think it needs to include the
+			-- ru_fn though.
+			-- Note [Rule dependency info] in OccurAnal
 
 emptySpecInfo :: SpecInfo
 emptySpecInfo = SpecInfo [] emptyVarSet
@@ -489,19 +491,15 @@ specInfoFreeVars (SpecInfo _ fvs) = fvs
 specInfoRules :: SpecInfo -> [CoreRule]
 specInfoRules (SpecInfo rules _) = rules
 
+setSpecInfoHead :: Name -> SpecInfo -> SpecInfo
+setSpecInfoHead fn (SpecInfo rules fvs)
+  = SpecInfo (map set_head rules) fvs
+  where
+    set_head rule = rule { ru_fn = fn }
+
 seqSpecInfo (SpecInfo rules fvs) = seqRules rules `seq` seqVarSet fvs
 \end{code}
 
-Note [Rule dependency info]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
-THe VarSet in a SpecInfo is used for dependency analysis in the 
-occurrence analyser.  We must track free vars in *both* lhs and rhs.  Why both?  
-Consider
-	x = y
- 	RULE f x = 4
-Then if we substitute y for x, we'd better do so in the
- rule's LHS too, so we'd better ensure the dependency is respsected
-
 
 
 %************************************************************************
@@ -704,11 +702,11 @@ zapLamInfo info@(IdInfo {occInfo = occ, newDemandInfo = demand})
 	-- The "unsafe" occ info is the ones that say I'm not in a lambda
 	-- because that might not be true for an unsaturated lambda
     is_safe_occ (OneOcc in_lam _ _) = in_lam
-    is_safe_occ other		    = True
+    is_safe_occ _other		    = True
 
     safe_occ = case occ of
 		 OneOcc _ once int_cxt -> OneOcc insideLam once int_cxt
-		 other	       	       -> occ
+		 _other	       	       -> occ
 
     is_safe_dmd Nothing    = True
     is_safe_dmd (Just dmd) = not (isStrictDmd dmd)
@@ -724,9 +722,13 @@ zapDemandInfo info@(IdInfo {newDemandInfo = dmd})
 \begin{code}
 zapFragileInfo :: IdInfo -> Maybe IdInfo
 -- Zap info that depends on free variables
-zapFragileInfo info = Just (info `setSpecInfo` emptySpecInfo
-				 `setWorkerInfo` NoWorker
-                                 `setUnfoldingInfo` NoUnfolding)
+zapFragileInfo info 
+  = Just (info `setSpecInfo` emptySpecInfo
+	       `setWorkerInfo` NoWorker
+               `setUnfoldingInfo` NoUnfolding
+	       `setOccInfo` if isFragileOcc occ then NoOccInfo else occ)
+  where
+    occ = occInfo info
 \end{code}
 
 %************************************************************************