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authorRichard Henderson <richard.henderson@linaro.org>2019-02-27 18:34:38 -0800
committerRichard Henderson <richard.henderson@linaro.org>2019-03-12 09:46:58 -0700
commit5d53b0f5d35248894bf7c223689e95600b88434e (patch)
tree221a7445d047c8b0782fafa295c36fc017e4a8b4 /docs/devel
parent3fdbf5d6794db253b0a5173204bbbcc8a17bc9d1 (diff)
decodetree: Document the usefulness of argument sets
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'docs/devel')
-rw-r--r--docs/devel/decodetree.rst7
1 files changed, 7 insertions, 0 deletions
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::
&reg3 ra rb rc