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Re: [PATCH 01/28] powerpc: Use generic fabs{f} implementations
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: Joseph Myers <joseph at codesourcery dot com>
- Cc: libc-alpha at sourceware dot org
- Date: Wed, 3 Apr 2019 08:04:57 +0700
- Subject: Re: [PATCH 01/28] powerpc: Use generic fabs{f} implementations
- References: <20190329133529.22523-1-adhemerval.zanella@linaro.org> <20190329133529.22523-2-adhemerval.zanella@linaro.org> <alpine.DEB.2.21.1904012003110.27216@digraph.polyomino.org.uk>
On 02/04/2019 03:04, Joseph Myers wrote:
> On Fri, 29 Mar 2019, Adhemerval Zanella wrote:
>
>> Since be2e25bbd78f9fdf the generic ieee754 implementation uses
>> compiler builtin which generates fabs{f} for all supported targets.
>
> One reason for the existing version might be a microoptimization for code
> size to make the float and double versions aliases, as permitted by the
> ABIs and instruction set in this case. (This is not an objection to this
> patch.)
>
Indeed powerpc does such microoptimizations for some implementations, but
if the idea is indeed to push such optimizations couldn't add on generic
implementation though a flag defined in arch-specific headers?