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Re: rtl questions
- To: Richard Henderson <rth at redhat dot com>
- Subject: Re: rtl questions
- From: Richard Earnshaw <rearnsha at arm dot com>
- Date: Thu, 19 Jul 2001 19:23:53 +0100
- cc: Bahman Sistany <bsistany at zucotto dot com>, gcc at gcc dot gnu dot org, Richard dot Earnshaw at arm dot com
- Organization: ARM Ltd.
- Reply-To: Richard dot Earnshaw at arm dot com
> > 2) Is it absolutley necessary to have a matching define_insn for a
> > define_expand?
>
> Yes. Rather it is not absolutely necessary to have a define_expand
> for the define_insn. If nothing special needs to happen, you can
> just name the define_insn appropriately.
More strictly there has to be a define_insn that matches any insn
*emitted* by the define_expand; if your expansion decomposes the original
"template" into simpler operations you need define_insn patterns to match
each of the simpler operations.