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Re: Supporting an instruction in the back-end - II
- From: Michael Meissner <michael dot meissner at amd dot com>
- To: Mohamed Shafi <shafitvm at gmail dot com>
- Cc: GCC <gcc at gcc dot gnu dot org>
- Date: Mon, 19 May 2008 15:09:06 -0400
- Subject: Re: Supporting an instruction in the back-end - II
- References: <ba0bd44d0805132148y61c2685eh1d4f9ffb7cc2571@mail.gmail.com>
On Wed, May 14, 2008 at 10:18:56AM +0530, Mohamed Shafi wrote:
> Hello all,
>
> Will it be possible to write a pattern in the md file to support
> setting/clearing a bit of a particular register?
> The instructions are as follows:
>
> clrb Rx, bitNo
> setb Rx, bitNo
>
> Could you point me to the back-ends that has support for this kind of
> instructions?
The standard name to extract a bit field is 'extv' (for sign extended
extraction), and 'extzv' (for zero extended extraction). The standard to set a
bit field is 'insv'. There are 18 different ports that support 'extv' or
'extzv' in some fashion, and 20 different ports that support 'insv'.
--
Michael Meissner, AMD
90 Central Street, MS 83-29, Boxborough, MA, 01719, USA
michael.meissner@amd.com