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Re: [PATCH 1/2] [SPARC] Prevent -mfix-ut699 from generating b2bst errata sequences
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Daniel Cederman <cederman at gaisler dot com>
- Cc: gcc-patches at gcc dot gnu dot org, sebastian dot huber at embedded-brains dot de, daniel at gaisler dot com
- Date: Tue, 05 Dec 2017 12:20:28 +0100
- Subject: Re: [PATCH 1/2] [SPARC] Prevent -mfix-ut699 from generating b2bst errata sequences
- Authentication-results: sourceware.org; auth=none
- References: <20171127100435.6055-1-cederman@gaisler.com> <20171127100435.6055-2-cederman@gaisler.com>
> The sequence
> st
> fdivd / fsqrtd
> std
> was generated in some cases with -mfix-ut699 when there was
> a st before the div/sqrt. This sequence could trigger the b2bst errata.
>
> Now the following safe sequence is generated instead:
> st
> nop
> fdivd / fsqrtd
> std
>
> gcc/ChangeLog:
>
> 2017-11-27 Martin Aberg <maberg@gaisler.com>
>
> * config/sparc/sparc.md (divdf3_fix): Add NOP and adjust length
> to prevent b2bst errata sequence.
> (sqrtdf2_fix): Likewise.
But isn't that the change I already rejected back in July?
https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00496.html
If so, what has changed since then? If nothing, then please revert.
--
Eric Botcazou