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Re: [PATCH, rs6000] Fix PR79261 (vec_xxpermdi is not endian-sensitive)
- From: Segher Boessenkool <segher at kernel dot crashing dot org>
- To: Bill Schmidt <wschmidt at linux dot vnet dot ibm dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, David Edelsohn <dje dot gcc at gmail dot com>
- Date: Fri, 17 Feb 2017 09:20:30 -0600
- Subject: Re: [PATCH, rs6000] Fix PR79261 (vec_xxpermdi is not endian-sensitive)
- Authentication-results: sourceware.org; auth=none
- References: <a4a77ab8-46bd-e0c1-5dcb-0e7beca1a10c@linux.vnet.ibm.com>
Hi Bill,
On Thu, Feb 16, 2017 at 02:16:02PM -0600, Bill Schmidt wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79261 records that the interface
> vec_xxpermdi isn't implemented in a bi-endian fashion; instead, it produces
> results appropriate for big-endian vector element numbering even when run on
> a little endian machine. This is not part of the "official vector API" from
> the ELFv2 ABI document, but should still have appropriate bi-endian behavior.
Maybe this needs adding (or updating) some documentation?
> +;; Special version of xxpermdi that retains big-endian semantics.
> +(define_expand "vsx_xxpermdi_<mode>_be"
> + [(match_operand:VSX_L 0 "vsx_register_operand" "")
> + (match_operand:VSX_L 1 "vsx_register_operand" "")
> + (match_operand:VSX_L 2 "vsx_register_operand" "")
> + (match_operand:QI 3 "u5bit_cint_operand" "")]
Please remove the "".
Okay with that and perhaps some doc changes. Thanks,
Segher