+interestingArgContext :: Id -> SimplCont -> Bool
+-- If the argument has form (f x y), where x,y are boring,
+-- and f is marked INLINE, then we don't want to inline f.
+-- But if the context of the argument is
+-- g (f x y)
+-- where g has rules, then we *do* want to inline f, in case it
+-- exposes a rule that might fire. Similarly, if the context is
+-- h (g (f x x))
+-- where h has rules, then we do want to inline f.
+-- The interesting_arg_ctxt flag makes this happen; if it's
+-- set, the inliner gets just enough keener to inline f
+-- regardless of how boring f's arguments are, if it's marked INLINE
+--
+-- The alternative would be to *always* inline an INLINE function,
+-- regardless of how boring its context is; but that seems overkill
+-- For example, it'd mean that wrapper functions were always inlined
+interestingArgContext fn cont
+ = idHasRules fn || go cont
+ where
+ go (Select {}) = False
+ go (ApplyTo {}) = False
+ go (ArgOf {}) = True
+ go (CoerceIt _ c) = go c
+ go (Stop _ _ interesting) = interesting
+
+-------------------