Comments only

1 files changed, 6 insertions, 8 deletions

diff --git a/compiler/codeGen/StgCmmCon.hs b/compiler/codeGen/StgCmmCon.hs
index 2ddeceb825..258896ff1a 100644
--- a/compiler/codeGen/StgCmmCon.hs
+++ b/compiler/codeGen/StgCmmCon.hs
@@ -272,14 +272,12 @@ bindConArgs (DataAlt con) base args
            -- when accessing the constructor field.
            bind_arg :: (NonVoid Id, ByteOff) -> FCode (Maybe LocalReg)
            bind_arg (arg@(NonVoid b), offset)
-             | isDeadBinder b =
-                 -- Do not load unused fields from objects to local variables.
-                 -- (CmmSink can optimize this, but it's cheap and common enough
-                 -- to handle here)
-                 return Nothing
-             | otherwise      = do
-                 emit $ mkTaggedObjectLoad dflags (idToReg dflags arg) base offset tag
-                 Just <$> bindArgToReg arg
+             | isDeadBinder b  -- See Note [Dead-binder optimisation] in StgCmmExpr
+             = return Nothing
+             | otherwise
+             = do { emit $ mkTaggedObjectLoad dflags (idToReg dflags arg)
+                                              base offset tag
+                  ; Just <$> bindArgToReg arg }
 
        mapMaybeM bind_arg args_w_offsets