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From: Stefan Liebler <stli@linux.ibm.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH 13/13] Use GCC builtins for copysign functions if desired.
Date: Tue, 03 Dec 2019 08:27:00 -0000	[thread overview]
Message-ID: <e3c29fb8-5a63-0a0a-a55c-3d7751b348b1@linux.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1912022059030.23075@digraph.polyomino.org.uk>

On 12/2/19 10:00 PM, Joseph Myers wrote:
> On Mon, 2 Dec 2019, Stefan Liebler wrote:
> 
>> This patch is using the corresponding GCC builtin for copysignf, copysign,
>> copysignl and copysignf128 if the USE_FUNCTION_BUILTIN macros are defined to one
>> in math-use-builtins.h.
> 
> I believe this is always safe for these implementations (the only case
> where GCC might not expand copysign functions inline is copysignl for IBM
> long double, in the soft-float case).
> 
Thus you mean we can do the following preset in 
sysdeps/generic/math-use-builtins.h?
#define USE_COPYSIGN_BUILTIN 1
#define USE_COPYSIGNF_BUILTIN 1
#define USE_COPYSIGNL_BUILTIN 0
#define USE_COPYSIGNF128_BUILTIN 0

Or even also set USE_COPYSIGNL_BUILTIN to one as IBM long double has its 
own implementation in ./sysdeps/ieee754/ldbl-128ibm/s_copysignl.c.

On the other hand, I'm not able to run tests on the different 
architectures. Thus the safest way would be to leave all those macros 
set to zero and let the architectures decide.

In each case, I would prefer to set those macros to one in a separate 
patch. Then this patch could be reverted in case of failing on one 
architecture.

  reply	other threads:[~2019-12-03  8:27 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-02 14:46 [PATCH 00/13] Use GCC builtins for some math " Stefan Liebler
2019-12-02 14:46 ` [PATCH 02/13] Always use wordsize-64 version of s_rint.c Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 03/13] Always use wordsize-64 version of s_floor.c Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 05/13] Always use wordsize-64 version of s_trunc.c Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 07/13] Use GCC builtins for nearbyint functions if desired Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 01/13] Always use wordsize-64 version of s_nearbyint.c Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 09/13] Use GCC builtins for floor functions if desired Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 14:46 ` [PATCH 08/13] Use GCC builtins for rint " Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 15:10 ` [PATCH 11/13] Use GCC builtins for trunc " Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 15:15 ` [PATCH 04/13] Always use wordsize-64 version of s_ceil.c Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 15:18 ` [PATCH 10/13] Use GCC builtins for ceil functions if desired Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 15:46 ` [PATCH 06/13] Always use wordsize-64 version of s_round.c Stefan Liebler
2019-12-05 20:40   ` Adhemerval Zanella
2019-12-02 15:50 ` [PATCH 12/13] Use GCC builtins for round functions if desired Stefan Liebler
2019-12-05 20:41   ` Adhemerval Zanella
2019-12-02 15:52 ` [PATCH 13/13] Use GCC builtins for copysign " Stefan Liebler
2019-12-02 21:00   ` Joseph Myers
2019-12-03  8:27     ` Stefan Liebler [this message]
2019-12-03 16:51       ` Joseph Myers
2019-12-04 13:15         ` Stefan Liebler
2019-12-04 13:20           ` Joseph Myers
2019-12-04 16:34             ` Stefan Liebler
2019-12-04 20:43               ` Joseph Myers
2019-12-05 15:40                 ` Stefan Liebler
2019-12-09 12:58 ` [PATCH 00/13] Use GCC builtins for some math " Stefan Liebler

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