This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] powerpc: Fix build of wcscpy with --disable-multi-arch
- From: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- To: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- Cc: nd <nd at arm dot com>, "Gabriel F. T. Gomes" <gabriel at inconstante dot eti dot br>, Tulio Magno Quites Machado Filho <tuliom at ascii dot art dot br>, "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>
- Date: Mon, 4 Mar 2019 18:09:53 +0000
- Subject: Re: [PATCH] powerpc: Fix build of wcscpy with --disable-multi-arch
Hi,
> Second, and this is minor one, I will send a patch to just remove the
> power6 wcs* optimized routines. They are rarely used in the wild, the
> optimization are just loop unrolling that we can either rely on
> compiler (sadly gcc does not unroll this kind of loop either with
> aggressive optimization flags) or add on generic implementation,
> and power6 and power7 are essentially the same binary for
> powerpc64.
I think we could remove all of the PPC multi-arch code since there isn't an
assembler implementation for these, and I find it hard to believe there is a
significant difference between -mcpu=power6 and power7.
The generic versions can be sped up via unrolling 4x and using base+immediate
addressing modes. It's also feasible to align the pointer and process 2-4 characters
in one go (possibly using wider accesses).
Wilco