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From: Joseph Myers <joseph@codesourcery.com>
To: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>
Cc: <libc-alpha@sourceware.org>
Subject: Re: [PATCH 3/3] powerpc64le: Disable compiler support for float128 when reusing ldbl-128
Date: Thu, 07 Sep 2017 14:45:00 -0000	[thread overview]
Message-ID: <alpine.DEB.2.20.1709071440200.21759@digraph.polyomino.org.uk> (raw)
In-Reply-To: <20170907104352.7748-4-gabriel@inconstante.eti.br>

On Thu, 7 Sep 2017, Gabriel F. T. Gomes wrote:

> Some files under sysdeps/ieee754/ldbl-128ibm are able to reuse the
> implementation in sysdeps/ieee754/ldbl-128 by defining _Float128 to long
> double.  This relies on compiler support for _Float128 being disabled.
> 
> On powerpc, such support is currently disabled by default, however, it
> will get enabled by default [1], requiring that this Makefile actively
> disable compiler support for float128 for the required files.

I think it would be better to stop #include of ldbl-128 files from 
ldbl-128ibm.  That is, copy the relevant source files (in the case of 
e_expl.c that's actually t_expl.h) to ldbl-128ibm, with _Float128 
converted to long double and L() also expanded back to adding L suffixes.  
And, in the e_lgammal_r.c case, then eliminate the present LDBL_MANT_DIG 
conditionals from both copies.

Long term I'd like the ldbl-128 files to e.g. use f128 constant suffixes 
directly (once we can assume GCC >= 7 to build glibc), with such changes 
cleaning up the code but being incompatible with its use also for 
ldbl-128ibm.

-- 
Joseph S. Myers
joseph@codesourcery.com

  reply	other threads:[~2017-09-07 14:45 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-07 10:44 [PATCH 0/3] Fixes for -mfloat128 being enabled by default on gcc for power Gabriel F. T. Gomes
2017-09-07 10:44 ` [PATCH 2/3] powerpc: Add redirection for finitef128, isinf128, and isnanf128 Gabriel F. T. Gomes
2017-09-07 14:39   ` Joseph Myers
2017-09-08 15:25     ` Gabriel F. T. Gomes
2017-09-08 16:24       ` Joseph Myers
2017-09-07 10:44 ` [PATCH 1/3] powerpc: Add -mfloat128 to tst-strtod-nan-locale testcase Gabriel F. T. Gomes
2017-09-07 10:44 ` [PATCH 3/3] powerpc64le: Disable compiler support for float128 when reusing ldbl-128 Gabriel F. T. Gomes
2017-09-07 14:45   ` Joseph Myers [this message]
2017-09-26 22:05 ` [PATCH 0/3] Fixes for -mfloat128 being enabled by default on gcc for power Joseph Myers

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