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Re: [PATCH][GCC][mid-end] Fix single use requirement for xorsign (x * copysign (1, y))
- From: Richard Biener <rguenther at suse dot de>
- To: Tamar Christina <Tamar dot Christina at arm dot com>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, nd <nd at arm dot com>, "law at redhat dot com" <law at redhat dot com>, "ian at airs dot com" <ian at airs dot com>
- Date: Wed, 23 Aug 2017 12:39:34 +0200 (CEST)
- Subject: Re: [PATCH][GCC][mid-end] Fix single use requirement for xorsign (x * copysign (1, y))
- Authentication-results: sourceware.org; auth=none
- References: <20170822162720.GA30641@arm.com> <DB6PR0802MB230906AD980064D3355E1543FF840@DB6PR0802MB2309.eurprd08.prod.outlook.com>
On Tue, 22 Aug 2017, Tamar Christina wrote:
> Sorry, forgot to add some maintainers :)
> ________________________________________
> From: gcc-patches-owner@gcc.gnu.org <gcc-patches-owner@gcc.gnu.org> on behalf of Tamar Christina <tamar.christina@arm.com>
> Sent: Tuesday, August 22, 2017 5:27:23 PM
> To: gcc-patches@gcc.gnu.org
> Cc: nd; law@redhat.com
> Subject: [PATCH][GCC][mid-end] Fix single use requirement for xorsign (x * copysign (1, y))
>
> Hi All,
>
> This patch fixes the placement of the single-use requirement for xorsign.
>
> on `x = a * copysign (1, b)` the intention was that `copysign (1, b)` be
> single use, and not `x`. Requiring `x` to be single use blocks transformation
> where we do want it to occur.
>
> Regtested on aarch64-none-linux-gnu and no regressions
> (only target currently supporting this).
>
> Ok for trunk?
Ok with re-ordering the checks -- has_single_use is cheaper than
is_copysign_call_with_1.
Thanks,
Richard.
> gcc/
> 2017-08-22 Tamar Christina <tamar.christina@arm.com>
>
> PR middle-end/19706
> * tree-ssa-math-opts.c (convert_expand_mult_copysign):
> Fix single-use check.
>
> --
>
>
--
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)