"Incorrectly" meaning a static-chain value passed to a function with
DECL_NO_STATIC_CHAIN set. "Incorrectly" meaning no static chain passed
to a function when it ought to have gotten one.
Passing a static chain to a function that doesn't need one is conservatively
correct. Are you implicitly referring to i386 where regparm can be altered
depending on the value of DECL_NO_STATIC_CHAIN? If so, I guess the static
chain register is loaded before the other register parameters so passing a
static chain to a function with DECL_NO_STATIC_CHAIN works too.