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Re: Eliminable register breakage
- To: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- Subject: Re: Eliminable register breakage
- From: Joern Rennecke <amylaar at redhat dot com>
- Date: Tue, 19 Jun 2001 00:44:47 +0100 (BST)
- Cc: gcc at gcc dot gnu dot org
> Register elimination will replace this with
>
> (set (reg:SI N) (subreg:SI (plus:DI SP (const_int C)) 0))
>
> and then expect reload to somehow "make this work". But it can't.
>
> How was this supposed to work?
I think if this is a WORD_REGISTER_OPERATIONS target with word_mode == DImode,
in little endian, this should be transformed to
(set (reg:DI N) (plus:DI SP (const_int C)))