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Re: [PATCH][GCC] Simplification of 1U << (31 - x)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Sudi Das <Sudi dot Das at arm dot com>
- Cc: Richard Biener <richard dot guenther at gmail dot com>, Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, nd <nd at arm dot com>, Richard Earnshaw <Richard dot Earnshaw at arm dot com>, James Greenhalgh <James dot Greenhalgh at arm dot com>
- Date: Tue, 26 Sep 2017 15:06:12 +0200
- Subject: Re: [PATCH][GCC] Simplification of 1U << (31 - x)
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- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Tue, Sep 26, 2017 at 12:44:10PM +0000, Sudi Das wrote:
>
> Still waiting on Jakub's comment on whether there are more things needed
> at the backend. But I have updated the patch according to Richard's
> comments.
Well, we don't want to regress performance wise on one of the most important
primary targets. I don't care that much if the RTL/backend work is done
together with the patch, or as a follow-up during stage1/3, but it should be
done, the testcases I've posted can be used as a basis of a P1 runtime
performance regression.
Jakub