+-- See Note [Unboxed tuple result discount]
+-- | isUnboxedTupleCon dc = SizeIs (_ILIT(0)) emptyBag (_ILIT(0))
+
+-- See Note [Constructor size]
+ | otherwise = SizeIs (_ILIT(1)) emptyBag (iUnbox n_val_args +# _ILIT(1))
+\end{code}
+
+Note [Constructor size]
+~~~~~~~~~~~~~~~~~~~~~~~
+Treat a constructors application as size 1, regardless of how many
+arguments it has; we are keen to expose them (and we charge separately
+for their args). We can't treat them as size zero, else we find that
+(Just x) has size 0, which is the same as a lone variable; and hence
+'v' will always be replaced by (Just x), where v is bound to Just x.
+
+However, unboxed tuples count as size zero. I found occasions where we had
+ f x y z = case op# x y z of { s -> (# s, () #) }
+and f wasn't getting inlined.
+
+Note [Unboxed tuple result discount]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+I tried giving unboxed tuples a *result discount* of zero (see the
+commented-out line). Why? When returned as a result they do not
+allocate, so maybe we don't want to charge so much for them If you
+have a non-zero discount here, we find that workers often get inlined
+back into wrappers, because it look like
+ f x = case $wf x of (# a,b #) -> (a,b)
+and we are keener because of the case. However while this change
+shrank binary sizes by 0.5% it also made spectral/boyer allocate 5%
+more. All other changes were very small. So it's not a big deal but I
+didn't adopt the idea.
+
+\begin{code}