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From: Richard Sandiford <richard.sandiford@arm.com>
To: Eric Botcazou <ebotcazou@adacore.com>
Mail-Followup-To: Eric Botcazou <ebotcazou@adacore.com>,<gcc-patches@gcc.gnu.org>, richard.sandiford@arm.com
Cc: <gcc-patches@gcc.gnu.org>
Subject: Re: New .md construct: define_insn_and_rewrite
References: <mptlfz9jf7b.fsf@arm.com> <2745710.abvoBQgxZg@polaris>
Date: Wed, 15 May 2019 06:48:00 -0000
In-Reply-To: <2745710.abvoBQgxZg@polaris> (Eric Botcazou's message of "Tue, 14	May 2019 18:56:27 +0200")
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Eric Botcazou <ebotcazou@adacore.com> writes:
>> This patch therefore adds a new construct called define_insn_and_rewrite.
>> It's basically a define_insn_and_split with an implicit split pattern,
>> obtained by copying the insn pattern and replacing match_operands with
>> match_dups and match_operators with match_op_dups.
>
> Isn't that what define_subst does in a different context?
>
>> Any comments?  Suggestions for better names?
>
> define_insn_and_subst?

define_subst is a static substitution though, creating multiple insn codes,
whereas the substitution here is dynamic and can be controlled by C++ code.
It might be confusing to link the two.

Thanks,
Richard