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Re: [PATCH] Cleanup FAST_MATH misc functions from sysdeps/x86/fpu/bits/mathinline.h
- From: Joseph Myers <joseph at codesourcery dot com>
- To: Uros Bizjak <ubizjak at gmail dot com>
- Cc: <libc-alpha at sourceware dot org>
- Date: Thu, 26 Apr 2018 12:00:26 +0000
- Subject: Re: [PATCH] Cleanup FAST_MATH misc functions from sysdeps/x86/fpu/bits/mathinline.h
- References: <CAFULd4a3CmrUYvTUVJTxEv1O1XwT84cKvmEAdbB9MROAdRxd7Q@mail.gmail.com>
On Thu, 26 Apr 2018, Uros Bizjak wrote:
> Hello!
>
> Attached patch cleans up FAST_MATH misc functions from
> sysdeps/x86/fpu/bits/mathinline.h. The patch uses x87 __builtin
What we actually want to do is eliminate bits/mathinline.h completely
(with libc-internal inlines moving to an internal header) (and then
eliminate the separate inline function ulps and tests). There may be a
few remaining cases that would be useful for GCC to optimize with
-ffast-math but that it doesn't currently have built-in optimizations for,
however.
The header, while it exists, does need to work with old GCC versions as
it's an installed header (optimizations might be disabled with old
versions, however).
> Patch was tested on x86_64-linux-gnu, and the resulting mathinline.h
> was used to calculate test results of all changed functions.
Note this code isn't used for 64-bit anyway (it's all inside "#if !defined
__SSE2_MATH__ && !defined __x86_64__").
--
Joseph S. Myers
joseph@codesourcery.com