On Wed, Jun 20, 2018 at 07:31:31PM -0500, Segher Boessenkool wrote:
> On Wed, Jun 20, 2018 at 10:25:36AM -0400, Michael Meissner wrote:
> > This code disables the automatic multilib creation unless you use the
> > --with-advance-toolchain=<xxx> option and the Advance Toolchain directoy has
> > been modified to have the lib64/ieee128 and/or lib64/ibm128 directories for
> > multilib support. This allows the multilib to still be created, but it is
> > not
> > enabled by default.
> >
> > Alternatively, I have a patch that disables the IEEE/IBM long double
> > multilib
> > support completely.
>
> So what are the advantages and the disadvantages of both approaches?
> And, why do you think this one is preferable?
The main advantge is that it makes it a little easier for me to test things,
since I only have to build one compiler instead of two. But that is fairly
minor.
Here is the alternate patch to eliminate the multilib support for IEEE/IBM long
double.
[gcc]
2018-06-21 Michael Meissner <meiss...@linux.ibm.com>
* config.gcc (powerpc64le*): Remove multilib support for IEEE and
IBM long double.
* config/rs6000/rs6000.c (rs6000_option_override_internal):
Likewise.
* config/rs6000/rs6000.h (TARGET_IEEEQUAD_MULTILIB): Likewise.
* config/rs6000/t-ldouble-linux64le-ibm: Delete, IEEE/IBM long
double multilib no longer supported.
* config/rs6000/t-ldouble-linux64le-ieee: Likewise.
* doc/install.texi (PowerPC options): Delete information about
IEEE/IBM long double multilibs.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
Index: gcc/config.gcc
===================================================================
--- gcc/config.gcc (revision 261755)
+++ gcc/config.gcc (working copy)
@@ -4566,16 +4566,6 @@ case "${target}" in
elif test x$with_long_double_format = xibm; then
tm_defines="${tm_defines} TARGET_IEEEQUAD_DEFAULT=0"
fi
-
- case "${target}:${enable_multilib}:${with_long_double_format}"
in
- powerpc64le*:yes:ieee | powerpc64le*:yes:ibm)
- tm_defines="${tm_defines} TARGET_IEEEQUAD_MULTILIB=1"
- tmake_file="${tmake_file}
rs6000/t-ldouble-linux64le-${with_long_double_format}"
- ;;
- *)
- :
- ;;
- esac
;;
s390*-*-*)
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 261755)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -4578,19 +4578,16 @@ rs6000_option_override_internal (bool gl
else if (rs6000_long_double_type_size == 128)
rs6000_long_double_type_size = FLOAT_PRECISION_TFmode;
- /* Set -mabi=ieeelongdouble on some old targets. In the future, power server
- systems will also set long double to be IEEE 128-bit. AIX and Darwin
- explicitly redefine TARGET_IEEEQUAD and TARGET_IEEEQUAD_DEFAULT to 0, so
- those systems will not pick up this default. Warn if the user changes the
- default unless either the user used the -Wno-psabi option, or the compiler
- was built to enable multilibs to switch between the two long double
- types. */
+ /* Set -mabi=ieeelongdouble on some old targets. Power server systems may
+ also set long double to be IEEE 128-bit using the configuration option
+ --with-long-double-forrmat=ieee. AIX and Darwin explicitly redefine
+ TARGET_IEEEQUAD and TARGET_IEEEQUAD_DEFAULT to 0, so those systems will
+ not pick up this default. Warn if the user changes the default unless
+ either the user used the -Wno-psabi option. */
if (!global_options_set.x_rs6000_ieeequad)
rs6000_ieeequad = TARGET_IEEEQUAD_DEFAULT;
- else if (!TARGET_IEEEQUAD_MULTILIB
- && rs6000_ieeequad != TARGET_IEEEQUAD_DEFAULT
- && TARGET_LONG_DOUBLE_128)
+ else if (rs6000_ieeequad != TARGET_IEEEQUAD_DEFAULT &&
TARGET_LONG_DOUBLE_128)
{
static bool warned_change_long_double;
if (!warned_change_long_double)
Index: gcc/config/rs6000/rs6000.h
===================================================================
--- gcc/config/rs6000/rs6000.h (revision 261755)
+++ gcc/config/rs6000/rs6000.h (working copy)
@@ -551,12 +551,6 @@ extern int rs6000_vector_align[];
#define TARGET_ALTIVEC_ABI rs6000_altivec_abi
#define TARGET_LDBRX (TARGET_POPCNTD || rs6000_cpu == PROCESSOR_CELL)
-/* Define as 1 if we support multilibs for switching long double between IEEE
- 128-bit floating point and IBM extended double. */
-#ifndef TARGET_IEEEQUAD_MULTILIB
-#define TARGET_IEEEQUAD_MULTILIB 0
-#endif
-
/* ISA 2.01 allowed FCFID to be done in 32-bit, previously it was 64-bit only.
Enable 32-bit fcfid's on any of the switches for newer ISA machines. */
#define TARGET_FCFID (TARGET_POWERPC64 \
Index: gcc/config/rs6000/t-ldouble-linux64le-ibm
===================================================================
--- gcc/config/rs6000/t-ldouble-linux64le-ibm (revision 261755)
+++ gcc/config/rs6000/t-ldouble-linux64le-ibm (working copy)
@@ -1,26 +0,0 @@
-# Long double multilib libraries for PowerPC 64-bit little endian systems using
-# IBM extended double as the long double type.
-#
-# Copyright (C) 2018 Free Software Foundation, Inc.
-#
-# This file is part of GCC.
-#
-# GCC is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3, or (at your option)
-# any later version.
-#
-# GCC is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with GCC; see the file COPYING3. If not see
-# <http://www.gnu.org/licenses/>.
-
-MULTILIB_OPTIONS += mabi=ieeelongdouble/mabi=ibmlongdouble
-MULTILIB_DIRNAMES += ieee128 ibm128
-MULTILIB_OSDIRNAMES += mabi.ibmlongdouble=../lib64$(call
if_multiarch,:powerpc64-linux-gnu) \
- mabi.ieeelongdouble=../lib64/ieee128$(call
if_multiarch,:powerpc64-linux-gnu) \
- ../lib64$(call if_multiarch,:powerpc64-linux-gnu)
Index: gcc/config/rs6000/t-ldouble-linux64le-ieee
===================================================================
--- gcc/config/rs6000/t-ldouble-linux64le-ieee (revision 261755)
+++ gcc/config/rs6000/t-ldouble-linux64le-ieee (working copy)
@@ -1,26 +0,0 @@
-# Long double multilib libraries for PowerPC 64-bit little endian systems using
-# IEEE 128-bit floating point as the long double type.
-#
-# Copyright (C) 2018 Free Software Foundation, Inc.
-#
-# This file is part of GCC.
-#
-# GCC is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3, or (at your option)
-# any later version.
-#
-# GCC is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with GCC; see the file COPYING3. If not see
-# <http://www.gnu.org/licenses/>.
-
-MULTILIB_OPTIONS += mabi=ieeelongdouble/mabi=ibmlongdouble
-MULTILIB_DIRNAMES += ieee128 ibm128
-MULTILIB_OSDIRNAMES += mabi.ibmlongdouble=../lib64/ibm128$(call
if_multiarch,:powerpc64-linux-gnu) \
- mabi.ieeelongdouble=../lib64$(call
if_multiarch,:powerpc64-linux-gnu) \
- ../lib64$(call if_multiarch,:powerpc64-linux-gnu)
Index: gcc/doc/install.texi
===================================================================
--- gcc/doc/install.texi (revision 261755)
+++ gcc/doc/install.texi (working copy)
@@ -1902,17 +1902,6 @@ Until all of the libraries are converted
point, it is not recommended to use
@option{--with-long-double-format=ieee}.
-On little endian PowerPC Linux systems, if you explicitly set the
-@code{long double} type, it will build multilibs to allow you to
-select either @code{long double} format, unless you disable multilibs
-with the @code{--disable-multilib} option. At present,
-@code{long double} multilibs are not built on big endian PowerPC Linux
-systems. If you are building multilibs, you will need to configure
-the compiler using the @option{--with-system-zlib} option.
-
-If you do not set the @code{long double} type explicitly, no multilibs
-will be generated.
-
@item --enable-fdpic
On SH Linux systems, generate ELF FDPIC code.
