gcc/libatomic/configure.ac
Victor Do Nascimento f6b9a064a2 Libatomic: AArch64: Convert all lse128 assembly to .insn directives
Given the lack of support for the LSE128 instructions in all but the
the most up-to-date version of Binutils (2.42), having the build-time
test for assembler support for these instructions often leads to the
building of Libatomic without support for LSE128-dependent atomic
function implementations.  This ultimately leads to different people
having different versions of Libatomic on their machines, depending on
which assembler was available at compilation time.

Furthermore, the conditional inclusion of these atomic function
implementations predicated on assembler support leads to a series of
`#if HAVE_FEAT_LSE128' guards scattered throughout the codebase and
the need for a series of aliases when the feature flag evaluates
to false.  The preprocessor macro guards, together with the
conditional aliasing leads to code that is cumbersome to understand
and maintain.

Both of the issues highlighted above will only get worse with the
coming support for LRCPC3 atomics which under the current scheme will
also require build-time checks.

Consequently, a better option for both consistency across builds and
code cleanness is to make recourse to the `.inst' directive.  By
replacing all novel assembly instructions for their hexadecimal
representation within `.inst's, we ensure that the Libatomic code is
both considerably cleaner and all machines build the same binary,
irrespective of binutils version available at compile time.

This patch therefore removes all configure checks for LSE128-support
in the assembler and all the guards and aliases that were associated
with `HAVE_FEAT_LSE128'

libatomic/ChangeLog:

	* acinclude.m4 (LIBAT_TEST_FEAT_AARCH64_LSE128): Delete.
	* auto-config.h.in (HAVE_FEAT_LSE128): Likewise
	* config/linux/aarch64/atomic_16.S: Replace all LSE128
	instructions with equivalent `.inst' directives.
	(HAVE_FEAT_LSE128): Remove all references.
	* configure: Regenerate.
	* configure.ac: Remove call to LIBAT_TEST_FEAT_AARCH64_LSE128.
2024-06-12 10:23:38 +01:00

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# Process this file with autoreconf to produce a configure script.
# Copyright (C) 2012-2024 Free Software Foundation, Inc.
#
# This file is part of the GNU Atomic Library (libatomic).
#
# Libatomic 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 of the License, or
# (at your option) any later version.
#
# Libatomic 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.
#
# Under Section 7 of GPL version 3, you are granted additional
# permissions described in the GCC Runtime Library Exception, version
# 3.1, as published by the Free Software Foundation.
#
# You should have received a copy of the GNU General Public License and
# a copy of the GCC Runtime Library Exception along with this program;
# see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
# <http://www.gnu.org/licenses/>.
AC_INIT([GNU Atomic Library], 1.0,,[libatomic])
AC_CONFIG_HEADER(auto-config.h)
# -------
# Options
# -------
AC_MSG_CHECKING([for --enable-version-specific-runtime-libs])
LIBAT_ENABLE(version-specific-runtime-libs, no, ,
[Specify that runtime libraries should be installed in a compiler-specific directory],
permit yes|no)
AC_MSG_RESULT($enable_version_specific_runtime_libs)
# We would like our source tree to be readonly. However when releases or
# pre-releases are generated, the flex/bison generated files as well as the
# various formats of manuals need to be included along with the rest of the
# sources. Therefore we have --enable-generated-files-in-srcdir to do
# just that.
AC_MSG_CHECKING([for --enable-generated-files-in-srcdir])
LIBAT_ENABLE(generated-files-in-srcdir, no, ,
[put copies of generated files in source dir intended for creating source
tarballs for users without texinfo bison or flex.],
permit yes|no)
AC_MSG_RESULT($enable_generated_files_in_srcdir)
AM_CONDITIONAL(GENINSRC, test "$enable_generated_files_in_srcdir" = yes)
# -------
# Gets build, host, target, *_vendor, *_cpu, *_os, etc.
#
# You will slowly go insane if you do not grok the following fact: when
# building this library, the top-level /target/ becomes the library's /host/.
#
# configure then causes --target to default to --host, exactly like any
# other package using autoconf. Therefore, 'target' and 'host' will
# always be the same. This makes sense both for native and cross compilers
# just think about it for a little while. :-)
#
# Also, if this library is being configured as part of a cross compiler, the
# top-level configure script will pass the "real" host as $with_cross_host.
#
# Do not delete or change the following two lines. For why, see
# http://gcc.gnu.org/ml/libstdc++/2003-07/msg00451.html
AC_CANONICAL_SYSTEM
target_alias=${target_alias-$host_alias}
# Sets up automake. Must come after AC_CANONICAL_SYSTEM. Each of the
# following is magically included in AUTOMAKE_OPTIONS in each Makefile.am.
# 1.9.0: minimum required version
# no-define: PACKAGE and VERSION will not be #define'd in config.h (a bunch
# of other PACKAGE_* variables will, however, and there's nothing
# we can do about that; they come from AC_INIT).
# no-dist: we don't want 'dist' and related rules.
# foreign: we don't follow the normal rules for GNU packages (no COPYING
# file in the top srcdir, etc, etc), so stop complaining.
# -Wall: turns on all automake warnings...
# -Wno-portability: ...except this one, since GNU make is required.
# -Wno-override: ... and this one, since we do want this in testsuite.
AM_INIT_AUTOMAKE([1.9.0 foreign no-dist -Wall -Wno-portability -Wno-override])
AM_ENABLE_MULTILIB(, ..)
GCC_WITH_TOOLEXECLIBDIR
# Calculate toolexeclibdir
# Also toolexecdir, though it's only used in toolexeclibdir
case ${enable_version_specific_runtime_libs} in
yes)
# Need the gcc compiler version to know where to install libraries
# and header files if --enable-version-specific-runtime-libs option
# is selected.
toolexecdir='$(libdir)/gcc/$(target_alias)'
toolexeclibdir='$(toolexecdir)/$(gcc_version)$(MULTISUBDIR)'
;;
no)
if test -n "$with_cross_host" &&
test x"$with_cross_host" != x"no"; then
# Install a library built with a cross compiler in tooldir, not libdir.
toolexecdir='$(exec_prefix)/$(target_alias)'
case ${with_toolexeclibdir} in
no)
toolexeclibdir='$(toolexecdir)/lib'
;;
*)
toolexeclibdir=${with_toolexeclibdir}
;;
esac
else
toolexecdir='$(libdir)/gcc-lib/$(target_alias)'
toolexeclibdir='$(libdir)'
fi
multi_os_directory=`$CC -print-multi-os-directory`
case $multi_os_directory in
.) ;; # Avoid trailing /.
*) toolexeclibdir=$toolexeclibdir/$multi_os_directory ;;
esac
;;
esac
AC_SUBST(toolexecdir)
AC_SUBST(toolexeclibdir)
# Check the compiler.
# The same as in boehm-gc and libstdc++. Have to borrow it from there.
# We must force CC to /not/ be precious variables; otherwise
# the wrong, non-multilib-adjusted value will be used in multilibs.
# As a side effect, we have to subst CFLAGS ourselves.
m4_rename([_AC_ARG_VAR_PRECIOUS],[real_PRECIOUS])
m4_define([_AC_ARG_VAR_PRECIOUS],[])
AC_PROG_CC
AM_PROG_AS
m4_rename_force([real_PRECIOUS],[_AC_ARG_VAR_PRECIOUS])
AC_SUBST(CFLAGS)
# In order to override CFLAGS_FOR_TARGET, all of our special flags go
# in XCFLAGS. But we need them in CFLAGS during configury. So put them
# in both places for now and restore CFLAGS at the end of config.
save_CFLAGS="$CFLAGS"
# Find other programs we need.
AC_CHECK_TOOL(AR, ar)
AC_CHECK_TOOL(NM, nm)
AC_CHECK_TOOL(RANLIB, ranlib, ranlib-not-found-in-path-error)
AC_PROG_INSTALL
# Configure libtool
AM_PROG_LIBTOOL
ACX_LT_HOST_FLAGS
AC_SUBST(enable_shared)
AC_SUBST(enable_static)
AM_MAINTAINER_MODE
AM_CONDITIONAL([ENABLE_DARWIN_AT_RPATH], [test x$enable_darwin_at_rpath = xyes])
# For libtool versioning info, format is CURRENT:REVISION:AGE
libtool_VERSION=3:0:2
AC_SUBST(libtool_VERSION)
# Check for used threading-model
AC_MSG_CHECKING([for thread model used by GCC])
target_thread_file=`$CC -v 2>&1 | sed -n 's/^Thread model: //p'`
AC_MSG_RESULT([$target_thread_file])
case "$target" in
*aarch64*)
ACX_PROG_CC_WARNING_OPTS([-march=armv8-a+lse],[enable_aarch64_lse])
;;
esac
AC_SUBST(SYSROOT_CFLAGS_FOR_TARGET)
# Get target configury.
. ${srcdir}/configure.tgt
if test -n "$UNSUPPORTED"; then
AC_MSG_ERROR([Configuration ${target} is unsupported.])
fi
# Write out the ifunc resolver arg type.
AC_DEFINE_UNQUOTED(IFUNC_RESOLVER_ARGS, $IFUNC_RESOLVER_ARGS,
[Define ifunc resolver function argument.])
# Disable fallbacks to __sync routines from libgcc. Otherwise we'll
# make silly decisions about what the cpu can do.
CFLAGS="$save_CFLAGS -fno-sync-libcalls $XCFLAGS"
# Check header files.
AC_STDC_HEADERS
ACX_HEADER_STRING
GCC_HEADER_STDINT(gstdint.h)
AC_CHECK_HEADERS([fenv.h])
# Check for common type sizes
LIBAT_FORALL_MODES([LIBAT_HAVE_INT_MODE])
# Check for compiler builtins of atomic operations.
LIBAT_TEST_ATOMIC_INIT
LIBAT_FORALL_MODES([LIBAT_HAVE_ATOMIC_LOADSTORE])
LIBAT_FORALL_MODES([LIBAT_HAVE_ATOMIC_TAS])
LIBAT_FORALL_MODES([LIBAT_HAVE_ATOMIC_EXCHANGE])
LIBAT_FORALL_MODES([LIBAT_HAVE_ATOMIC_CAS])
LIBAT_FORALL_MODES([LIBAT_HAVE_ATOMIC_FETCH_ADD])
LIBAT_FORALL_MODES([LIBAT_HAVE_ATOMIC_FETCH_OP])
AC_C_BIGENDIAN
# I don't like the default behaviour of WORDS_BIGENDIAN undefined for LE.
AH_BOTTOM(
[#ifndef WORDS_BIGENDIAN
#define WORDS_BIGENDIAN 0
#endif])
LIBAT_WORDSIZE
# Check to see if -pthread or -lpthread is needed. Prefer the former.
# In case the pthread.h system header is not found, this test will fail.
case " $config_path " in
*" posix "*)
XPCFLAGS=""
CFLAGS="$CFLAGS -pthread"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[#include <pthread.h>
void *g(void *d) { return NULL; }],
[pthread_t t; pthread_create(&t,NULL,g,NULL);])],
[XPCFLAGS=" -pthread"],
[CFLAGS="$save_CFLAGS $XCFLAGS" LIBS="-lpthread $LIBS"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[#include <pthread.h>
void *g(void *d) { return NULL; }],
[pthread_t t; pthread_create(&t,NULL,g,NULL);])],
[],
[AC_MSG_ERROR([Pthreads are required to build libatomic])])])
CFLAGS="$save_CFLAGS $XPCFLAGS"
;;
esac
# See what sort of export controls are available.
LIBAT_CHECK_ATTRIBUTE_VISIBILITY
LIBAT_CHECK_ATTRIBUTE_DLLEXPORT
LIBAT_CHECK_ATTRIBUTE_ALIAS
if test x$try_ifunc = xyes; then
LIBAT_CHECK_IFUNC
fi
# Check linker support.
LIBAT_ENABLE_SYMVERS
# Cleanup and exit.
CFLAGS="$save_CFLAGS"
AC_CACHE_SAVE
AC_ARG_ENABLE([werror],
[AS_HELP_STRING([--disable-werror], [disable building with -Werror])])
# Add -Wall -Werror if we are using GCC.
AS_IF([test "x$GCC" = "xyes"],
[XCFLAGS="$XCFLAGS -Wall"])
AS_IF([test "x$enable_werror" != "xno" && test "x$GCC" = "xyes"],
[XCFLAGS="$XCFLAGS -Werror"])
# Add CET specific flags if CET is enabled
GCC_CET_FLAGS(CET_FLAGS)
XCFLAGS="$XCFLAGS $CET_FLAGS"
XCFLAGS="$XCFLAGS $XPCFLAGS"
AC_SUBST(config_path)
AC_SUBST(XCFLAGS)
AC_SUBST(XLDFLAGS)
AC_SUBST(LIBS)
AC_SUBST(SIZES)
# Conditionalize the makefile for this target machine.
tmake_file_=
for f in ${tmake_file}
do
if test -f ${srcdir}/config/$f
then
tmake_file_="${tmake_file_} \$(srcdir)/config/$f"
fi
done
tmake_file="${tmake_file_}"
AC_SUBST(tmake_file)
AM_CONDITIONAL(HAVE_IFUNC, test x$libat_cv_have_ifunc = xyes)
AM_CONDITIONAL(ARCH_AARCH64_LINUX,
[expr "$config_path" : ".* linux/aarch64 .*" > /dev/null])
AM_CONDITIONAL(ARCH_ARM_LINUX,
[expr "$config_path" : ".* linux/arm .*" > /dev/null])
AM_CONDITIONAL(ARCH_I386,
[test "$ARCH" = x86 && test x$libat_cv_wordsize = x4])
AM_CONDITIONAL(ARCH_X86_64,
[test "$ARCH" = x86 && test x$libat_cv_wordsize = x8])
# Determine what GCC version number to use in filesystem paths.
GCC_BASE_VER
if test ${multilib} = yes; then
multilib_arg="--enable-multilib"
else
multilib_arg=
fi
AC_CONFIG_FILES(Makefile testsuite/Makefile)
AC_CONFIG_FILES(testsuite/libatomic-site-extra.exp)
AC_OUTPUT