From 5d53b0f5d35248894bf7c223689e95600b88434e Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 27 Feb 2019 18:34:38 -0800 Subject: decodetree: Document the usefulness of argument sets Reviewed-by: Bastian Koppelmann Signed-off-by: Richard Henderson --- docs/devel/decodetree.rst | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'docs') diff --git a/docs/devel/decodetree.rst b/docs/devel/decodetree.rst index d9be30b2db..62cb7f687c 100644 --- a/docs/devel/decodetree.rst +++ b/docs/devel/decodetree.rst @@ -69,6 +69,13 @@ with each of the fields being one of the member arguments. If ``!extern`` is specified, the backing structure is assumed to have been already declared, typically via a second decoder. +Argument sets are useful when one wants to define helper functions +for the translator functions that can perform operations on a common +set of arguments. This can ensure, for instance, that the ``AND`` +pattern and the ``OR`` pattern put their operands into the same named +structure, so that a common ``gen_logic_insn`` may be able to handle +the operations common between the two. + Argument set examples:: ®3 ra rb rc -- cgit v1.2.3