[project @ 2003-02-04 15:09:38 by simonpj]

[ghc-hetmet.git] / ghc / compiler / basicTypes / IdInfo.lhs

diff --git a/ghc/compiler/basicTypes/IdInfo.lhs b/ghc/compiler/basicTypes/IdInfo.lhs
index 5dd5854..7555cc2 100644 (file)
--- a/ghc/compiler/basicTypes/IdInfo.lhs
+++ b/ghc/compiler/basicTypes/IdInfo.lhs
@@ -80,7 +80,7 @@ module IdInfo (
 
 
 import CoreSyn
-import Type            ( Type, usOnce, eqUsage )
+import Type            ( Type )
 import PrimOp          ( PrimOp )
 import NameEnv         ( NameEnv, lookupNameEnv )
 import Name            ( Name )
@@ -94,7 +94,6 @@ import BasicTypes     ( OccInfo(..), isFragileOcc, isDeadOcc, seqOccInfo, isLoopBrea
 import DataCon         ( DataCon )
 import ForeignCall     ( ForeignCall )
 import FieldLabel      ( FieldLabel )
-import Type            ( usOnce )
 import Demand          hiding( Demand, seqDemand )
 import qualified Demand
 import NewDemand
@@ -642,42 +641,28 @@ instance Show CprInfo where
 %************************************************************************
 
 If the @Id@ is a lambda-bound variable then it may have lambda-bound
-var info.  The usage analysis (UsageSP) detects whether the lambda
-binding this var is a ``one-shot'' lambda; that is, whether it is
-applied at most once.
+var info.  Sometimes we know whether the lambda binding this var is a
+``one-shot'' lambda; that is, whether it is applied at most once.
 
 This information may be useful in optimisation, as computations may
 safely be floated inside such a lambda without risk of duplicating
 work.
 
 \begin{code}
-data LBVarInfo
-  = NoLBVarInfo
-
-  | LBVarInfo Type             -- The lambda that binds this Id has this usage
-                               --   annotation (i.e., if ==usOnce, then the
-                               --   lambda is applied at most once).
-                               -- The annotation's kind must be `$'
-                               -- HACK ALERT! placing this info here is a short-term hack,
-                               --   but it minimises changes to the rest of the compiler.
-                               --   Hack agreed by SLPJ/KSW 1999-04.
+data LBVarInfo = NoLBVarInfo 
+              | IsOneShotLambda        -- The lambda is applied at most once).
 
 seqLBVar l = l `seq` ()
 \end{code}
 
 \begin{code}
-hasNoLBVarInfo NoLBVarInfo = True
-hasNoLBVarInfo other       = False
+hasNoLBVarInfo NoLBVarInfo     = True
+hasNoLBVarInfo IsOneShotLambda = False
 
 noLBVarInfo = NoLBVarInfo
 
--- not safe to print or parse LBVarInfo because it is not really a
--- property of the definition, but a property of the context.
 pprLBVarInfo NoLBVarInfo     = empty
-pprLBVarInfo (LBVarInfo u)   | u `eqUsage` usOnce
-                             = ptext SLIT("OneShot")
-                             | otherwise
-                             = empty
+pprLBVarInfo IsOneShotLambda = ptext SLIT("OneShot")
 
 instance Outputable LBVarInfo where
     ppr = pprLBVarInfo