[project @ 2005-08-10 11:09:05 by simonpj]

[ghc-hetmet.git] / ghc / compiler / coreSyn / CoreUtils.lhs

diff --git a/ghc/compiler/coreSyn/CoreUtils.lhs b/ghc/compiler/coreSyn/CoreUtils.lhs
index d3cc3d7..53761d5 100644 (file)
--- a/ghc/compiler/coreSyn/CoreUtils.lhs
+++ b/ghc/compiler/coreSyn/CoreUtils.lhs
@@ -16,7 +16,7 @@ module CoreUtils (
        -- Properties of expressions
        exprType, coreAltType,
        exprIsDupable, exprIsTrivial, exprIsCheap, 
-       exprIsValue,exprOkForSpeculation, exprIsBig, 
+       exprIsHNF,exprOkForSpeculation, exprIsBig, 
        exprIsConApp_maybe, exprIsBottom,
        rhsIsStatic,
 
@@ -557,7 +557,7 @@ idAppIsBottom :: Id -> Int -> Bool
 idAppIsBottom id n_val_args = appIsBottom (idNewStrictness id) n_val_args
 \end{code}
 
-@exprIsValue@ returns true for expressions that are certainly *already* 
+@exprIsHNF@ returns true for expressions that are certainly *already* 
 evaluated to *head* normal form.  This is used to decide whether it's ok 
 to change
 
@@ -581,8 +581,8 @@ this form is illegal (see the invariants in CoreSyn).  Args of unboxed
 type must be ok-for-speculation (or trivial).
 
 \begin{code}
-exprIsValue :: CoreExpr -> Bool                -- True => Value-lambda, constructor, PAP
-exprIsValue (Var v)    -- NB: There are no value args at this point
+exprIsHNF :: CoreExpr -> Bool          -- True => Value-lambda, constructor, PAP
+exprIsHNF (Var v)      -- NB: There are no value args at this point
   =  isDataConWorkId v         -- Catches nullary constructors, 
                        --      so that [] and () are values, for example
   || idArity v > 0     -- Catches (e.g.) primops that don't have unfoldings
@@ -591,14 +591,14 @@ exprIsValue (Var v)       -- NB: There are no value args at this point
        -- A worry: what if an Id's unfolding is just itself: 
        -- then we could get an infinite loop...
 
-exprIsValue (Lit l)         = True
-exprIsValue (Type ty)       = True     -- Types are honorary Values; 
+exprIsHNF (Lit l)           = True
+exprIsHNF (Type ty)         = True     -- Types are honorary Values; 
                                        -- we don't mind copying them
-exprIsValue (Lam b e)               = isRuntimeVar b || exprIsValue e
-exprIsValue (Note _ e)              = exprIsValue e
-exprIsValue (App e (Type _)) = exprIsValue e
-exprIsValue (App e a)        = app_is_value e [a]
-exprIsValue other           = False
+exprIsHNF (Lam b e)         = isRuntimeVar b || exprIsHNF e
+exprIsHNF (Note _ e)        = exprIsHNF e
+exprIsHNF (App e (Type _)) = exprIsHNF e
+exprIsHNF (App e a)        = app_is_value e [a]
+exprIsHNF other             = False
 
 -- There is at least one value argument
 app_is_value (Var fun) args
@@ -1212,7 +1212,7 @@ rhsIsStatic :: HomeModules -> CoreExpr -> Bool
 --     t = /\a. (:) (case w a of ...) (Nil a)  FALSE (redex)
 --
 --
--- This is a bit like CoreUtils.exprIsValue, with the following differences:
+-- This is a bit like CoreUtils.exprIsHNF, with the following differences:
 --    a) scc "foo" (\x -> ...) is updatable (so we catch the right SCC)
 --
 --    b) (C x xs), where C is a contructors is updatable if the application is