+
+idRuleRhsVars :: Id -> VarSet -- Does *not* include the CoreUnfolding vars
+-- Just the variables free on the *rhs* of a rule
+-- See Note [Choosing loop breakers] in Simplify.lhs
+idRuleRhsVars id = foldr (unionVarSet . ruleRhsFreeVars)
+ emptyVarSet
+ (idCoreRules id)
+
+idUnfoldingVars :: Id -> VarSet
+-- Produce free vars for an unfolding, but NOT for an ordinary
+-- (non-inline) unfolding, since it is a dup of the rhs
+-- and we'll get exponential behaviour if we look at both unf and rhs!
+-- But do look at the *real* unfolding, even for loop breakers, else
+-- we might get out-of-scope variables
+idUnfoldingVars id
+ = case realIdUnfolding id of
+ CoreUnfolding { uf_tmpl = rhs, uf_src = src }
+ | isInlineRuleSource src
+ -> exprFreeVars rhs
+ DFunUnfolding _ _ args -> exprsFreeVars args
+ _ -> emptyVarSet