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.
Fix libatomic build to support --disable-gnu-indirect-function on AArch64.
Always build atomic_16.S, add aliases to the __atomic_ functions if !HAVE_IFUNC.
Include auto-config.h in atomic_16.S to avoid having to pass defines via
makefiles. Fix build if HWCAP_ATOMICS/CPUID are not defined.
libatomic:
PR target/113986
* Makefile.in: Regenerated.
* Makefile.am: Make atomic_16.S not depend on HAVE_IFUNC.
Remove predefine of HAVE_FEAT_LSE128.
* acinclude.m4: Remove ARCH_AARCH64_HAVE_LSE128.
* configure: Regenerated.
* config/linux/aarch64/atomic_16.S: Add __atomic_ alias if !HAVE_IFUNC.
* config/linux/aarch64/host-config.h: Correctly handle !HAVE_IFUNC.
Add defines for HWCAP_ATOMICS and HWCAP_CPUID.
The armv9.4-a architectural revision adds three new atomic operations
associated with the LSE128 feature:
* LDCLRP - Atomic AND NOT (bitclear) of a location with 128-bit
value held in a pair of registers, with original data loaded into
the same 2 registers.
* LDSETP - Atomic OR (bitset) of a location with 128-bit value held
in a pair of registers, with original data loaded into the same 2
registers.
* SWPP - Atomic swap of one 128-bit value with 128-bit value held
in a pair of registers.
It is worth noting that in keeping with existing 128-bit atomic
operations in `atomic_16.S', we have chosen to merge certain
less-restrictive orderings into more restrictive ones. This is done
to minimize the number of branches in the atomic functions, minimizing
both the likelihood of branch mispredictions and, in keeping code
small, limit the need for extra fetch cycles.
Past benchmarking has revealed that acquire is typically slightly
faster than release (5-10%), such that for the most frequently used
atomics (CAS and SWP) it makes sense to add support for acquire, as
well as release.
Likewise, it was identified that combining acquire and release typically
results in little to no penalty, such that it is of negligible benefit
to distinguish between release and acquire-release, making the
combining release/acq_rel/seq_cst a worthwhile design choice.
This patch adds the logic required to make use of these when the
architectural feature is present and a suitable assembler available.
In order to do this, the following changes are made:
1. Add a configure-time check to check for LSE128 support in the
assembler.
2. Edit host-config.h so that when N == 16, nifunc = 2.
3. Where available due to LSE128, implement the second ifunc, making
use of the novel instructions.
4. For atomic functions unable to make use of these new
instructions, define a new alias which causes the _i1 function
variant to point ahead to the corresponding _i2 implementation.
libatomic/ChangeLog:
* Makefile.am (AM_CPPFLAGS): add conditional setting of
-DHAVE_FEAT_LSE128.
* acinclude.m4 (LIBAT_TEST_FEAT_AARCH64_LSE128): New.
* config/linux/aarch64/atomic_16.S (LSE128): New macro
definition.
(libat_exchange_16): New LSE128 variant.
(libat_fetch_or_16): Likewise.
(libat_or_fetch_16): Likewise.
(libat_fetch_and_16): Likewise.
(libat_and_fetch_16): Likewise.
* config/linux/aarch64/host-config.h (IFUNC_COND_2): New.
(IFUNC_NCOND): Add operand size checking.
(has_lse2): Renamed from `ifunc1`.
(has_lse128): New.
(HWCAP2_LSE128): Likewise.
* configure.ac: Add call to
LIBAT_TEST_FEAT_AARCH64_LSE128.
* configure (ac_subst_vars): Regenerated via autoreconf.
* Makefile.in: Likewise.
* auto-config.h.in: Likewise.
libatomic/ChangeLog:
* acinclude.m4: Detect *_ld_is_mold and use it.
* configure: Regenerate.
libgomp/ChangeLog:
* acinclude.m4: Detect *_ld_is_mold and use it.
* configure: Regenerate.
libitm/ChangeLog:
* acinclude.m4: Detect *_ld_is_mold and use it.
* configure: Regenerate.
libstdc++-v3/ChangeLog:
* acinclude.m4: Detect *_ld_is_mold and use it.
* configure: Regenerate.
2019-09-03 Chung-Lin Tang <cltang@codesourcery.com>
libatomic/
PR other/79543
* acinclude.m4 (LIBAT_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libffi/
PR other/79543
* acinclude.m4 (LIBAT_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libgomp/
PR other/79543
* acinclude.m4 (LIBGOMP_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libitm/
PR other/79543
* acinclude.m4 (LIBITM_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libstdc++-v3/
PR other/79543
* acinclude.m4 (GLIBCXX_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
From-SVN: r275341
This patch updates GCC to use autoconf 2.69 and automake 1.15.1.
(That's not the latest automake version, but it's the one used by
binutils-gdb, with which consistency is desirable, and in any case
seems a useful incremental update that should make a future update to
1.16.1 easier.)
The changes are generally similar to the binutils-gdb ones, and are
copied from there where shared files and directories are involved
(there are some further changes to such shared directories, however,
which I'd expect to apply to binutils-gdb once this patch is in GCC).
Largely, obsolete AC_PREREQ calls are removed, while many
AC_LANG_SOURCE calls are added to avoid warnings from aclocal and
autoconf. Multilib support is no longer included in core automake,
meaning that multilib.am needs copying from automake's contrib
directory into the GCC source tree. Autoconf 2.69 has Go support, so
local copies of that support are removed. I hope the D support will
soon be submitted to upstream autoconf so the local copy of that can
be removed in a future update. Changes to how automake generates
runtest calls mean quotes are removed from RUNTEST definitions in five
lib*/testsuite/Makefile.am files (libatomic, libgomp, libitm,
libphobos, libvtv; some others have RUNTEST definitions without
quotes, which are still OK); libgo and libphobos also get
-Wno-override added to AM_INIT_AUTOMAKE so those overrides of RUNTEST
do not generate automake warnings.
Note that the regeneration did not include regeneration of
fixincludes/config.h.in (attempting such regeneration resulted in all
the USED_FOR_TARGET conditionals disappearing; and I don't see
anything in the fixincludes/ directory that would result in such
conditionals being generated, unlike in the gcc/ directory). Also
note that libvtv/testsuite/other-tests/Makefile.in was not
regenerated; that directory is not listed as a subdirectory for which
Makefile.in gets regenerated by calling "automake" in libvtv/, so I'm
not sure how it's meant to be regenerated.
While I mostly fixed warnings should running aclocal / automake /
autoconf, there were various such warnings from automake in the
libgfortran, libgo, libgomp, liboffloadmic, libsanitizer, libphobos
directories that I did not fix, preferring to leave those to the
relevant subsystem maintainers. Specifically, most of those warnings
were of the following form (example from libgfortran):
Makefile.am:48: warning: source file 'caf/single.c' is in a subdirectory,
Makefile.am:48: but option 'subdir-objects' is disabled
automake: warning: possible forward-incompatibility.
automake: At least a source file is in a subdirectory, but the 'subdir-objects'
automake: automake option hasn't been enabled. For now, the corresponding output
automake: object file(s) will be placed in the top-level directory. However,
automake: this behaviour will change in future Automake versions: they
will
automake: unconditionally cause object files to be placed in the same subdirectory
automake: of the corresponding sources.
automake: You are advised to start using 'subdir-objects' option throughout your
automake: project, to avoid future incompatibilities.
I think it's best for the relevant maintainers to add subdir-objects
and do any other associated Makefile.am changes needed. In some cases
the paths in the warnings involved ../; I don't know if that adds any
extra complications to the use of subdir-objects.
I've tested this with native, cross and Canadian cross builds. The
risk of any OS-specific issues should I hope be rather lower than if a
libtool upgrade were included (we *should* do such an upgrade at some
point, but it's more complicated - it involves identifying all our
local libtool changes to see if any aren't included in the upstream
version we update to, and reverting an upstream libtool patch that's
inappropriate for use in GCC); I think it would be better to get this
update into GCC so that people can test in different configurations
and we can fix any issues found, rather than to try to get more and
more testing done before it goes in.
top level:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* multilib.am: New file. From automake.
Merge from binutils-gdb:
2018-06-19 Simon Marchi <simon.marchi@ericsson.com>
* libtool.m4: Use AC_LANG_SOURCE.
* configure.ac: Remove AC_PREREQ, use AC_LANG_SOURCE.
* ar-lib: New file.
* test-driver: New file.
* configure: Re-generate.
config:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* math.m4, tls.m4: Use AC_LANG_SOURCE.
Merge from binutils-gdb:
2018-06-19 Simon Marchi <simon.marchi@ericsson.com>
* override.m4 (_GCC_AUTOCONF_VERSION): Bump from 2.64 to 2.69.
fixincludes:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ.
* aclocal.m4, configure: Regenerate.
gcc:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE. Use single
line for second argument of AC_DEFINE_UNQUOTED.
* doc/install.texi (Tools/packages necessary for modifying GCC):
Update to autoconf 2.69 and automake 1.15.1.
* aclocal.m4, config.in, configure: Regenerate.
gnattools:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ.
* configure: Regenerate.
gotools:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* config/go.m4: Remove file.
* Makefile.am (ACLOCAL_AMFLAGS): Do not use -I ./config.
* configure.ac: Remove AC_PREREQ. Do not include config/go.m4.
* Makefile.in, aclocal.m4, configure: Regenerate.
intl:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
Merge from binutils-gdb:
2018-06-19 Simon Marchi <simon.marchi@ericsson.com>
* configure.ac: Add AC_USE_SYSTEM_EXTENSIONS, remove AC_PREREQ.
* configure: Re-generate.
* config.h.in: Re-generate.
* aclocal.m4: Re-generate.
libada:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ.
* configure: Regenerate.
libatomic:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* acinclude.m4: Use AC_LANG_SOURCE.
* configure.ac: Remove AC_PREREQ.
* testsuite/Makefile.am (RUNTEST): Remove quotes.
* Makefile.in, aclocal.m4, configure, testsuite/Makefile.in:
Regenerate.
libbacktrace:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE.
* Makefile.in, aclocal.m4, config.h.in, configure: Regenerate.
libcc1:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, configure: Regenerate.
libcpp:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE.
* aclocal.m4, config.in, configure: Regenerate.
libdecnumber:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
Merge from binutils-gdb:
2018-06-19 Simon Marchi <simon.marchi@ericsson.com>
* configure.ac: Remove AC_PREREQ.
* configure: Re-generate.
* aclocal.m4.
libffi:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
(AUTOMAKE_OPTIONS): Add info-in-builddir.
(CLEANFILES): Remove doc/libffi.info.
* configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, configure, fficonfig.h.in,
include/Makefile.in, man/Makefile.in, testsuite/Makefile.in:
Regenerate.
libgcc:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE.
* configure: Regenerate.
libgfortran:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, config.h.in, configure: Regenerate.
libgo [logically part of this change but omitted from the commit]:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* config/go.m4: Remove file.
* config/libtool.m4: Use AC_LANG_SOURCE.
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE. Use
-Wno-override in AM_INIT_AUTOMAKE call.
* Makefile.in, aclocal.m4, configure, testsuite/Makefile.in:
Regenerate.
libgomp:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am
(AUTOMAKE_OPTIONS): Add info-in-builddir.
(CLEANFILES): Remove libgomp.info.
* configure.ac: Remove AC_PREREQ.
* testsuite/Makefile.am (RUNTEST): Remove quotes.
* Makefile.in, aclocal.m4, configure, testsuite/Makefile.in:
Regenerate.
libhsail-rt:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, configure: Regenerate.
libiberty:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
Merge from binutils-gdb:
2018-06-19 Simon Marchi <simon.marchi@ericsson.com>
* configure.ac: Remove AC_PREREQ.
* configure: Re-generate.
* config.in: Re-generate.
libitm:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
(AUTOMAKE_OPTIONS): Add info-in-builddir.
(CLEANFILES): Remove libitm.info.
* configure.ac: Remove AC_PREREQ.
* testsuite/Makefile.am (RUNTEST): Remove quotes.
* Makefile.in, aclocal.m4, configure, testsuite/Makefile.in:
Regenerate.
libobjc:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ.
* aclocal.m4, config.h.in, configure: Regenerate.
liboffloadmic:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ.
* plugin/Makefile.am: Include multilib.am.
* plugin/configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, configure, plugin/Makefile.in,
plugin/aclocal.m4, plugin/configure: Regenerate.
libphobos:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ. Use -Wno-override in
AM_INIT_AUTOMAKE call.
* m4/autoconf.m4: Add extra argument to AC_LANG_DEFINE call.
* m4/druntime/os.m4: Use AC_LANG_SOURCE.
* testsuite/Makefile.am (RUNTEST): Remove quotes.
* Makefile.in, aclocal.m4, configure, libdruntime/Makefile.in,
src/Makefile.in, testsuite/Makefile.in: Regenerate.
libquadmath:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
(AUTOMAKE_OPTIONS): Remove 1.8. Add info-in-builddir.
(all-local): Define outside conditional code.
(CLEANFILES): Remove libquadmath.info.
* configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, config.h.in, configure: Regenerate.
libsanitizer:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE.
* Makefile.in, aclocal.m4, asan/Makefile.in, configure,
interception/Makefile.in, libbacktrace/Makefile.in,
lsan/Makefile.in, sanitizer_common/Makefile.in, tsan/Makefile.in,
ubsan/Makefile.in: Regenerate.
libssp:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
(AUTOMAKE_OPTIONS): Remove 1.9.5.
* configure.ac: Remove AC_PREREQ. Quote argument to
AC_RUN_IFELSE.
* Makefile.in, aclocal.m4, configure: Regenerate.
libstdc++-v3:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ.
* Makefile.in, aclocal.m4, configure, doc/Makefile.in,
include/Makefile.in, libsupc++/Makefile.in, po/Makefile.in,
python/Makefile.in, src/Makefile.in, src/c++11/Makefile.in,
src/c++17/Makefile.in, src/c++98/Makefile.in,
src/filesystem/Makefile.in, testsuite/Makefile.in: Regenerate.
libvtv:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
* configure.ac: Remove AC_PREREQ.
* testsuite/Makefile.am (RUNTEST): Remove quotes.
* Makefile.in, aclocal.m4, configure, testsuite/Makefile.in:
Regenerate.
lto-plugin:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* configure.ac: Remove AC_PREREQ. Use AC_LANG_SOURCE.
* Makefile.in, aclocal.m4, config.h.in, configure: Regenerate.
zlib:
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856
* Makefile.am: Include multilib.am.
Merge from binutils-gdb:
2018-06-19 Simon Marchi <simon.marchi@ericsson.com>
* configure.ac: Modernize AC_INIT call, remove AC_PREREQ.
* Makefile.am (AUTOMAKE_OPTIONS): Remove 1.8, cygnus, add foreign.
* Makefile.in: Re-generate.
* aclocal.m4: Re-generate.
* configure: Re-generate.
From-SVN: r265695
libatomic/ChangeLog:
2017-10-02 Martin Sebor <msebor@redhat.com>
PR c/81854
* acinclude.m4 (LIBAT_CHECK_IFUNC): Have ifunc resolver return
a function pointer rather than void* to avoid GCC 8 warnings.
* configure: Regenerate.
* libatomic_i.h: Declare ifunc resolvers to return function
pointers rather than void*.
From-SVN: r253372
gcc/
* builtins.c (fold_builtin_atomic_always_lock_free): Make "lock-free"
conditional on existance of a fast atomic load.
* optabs-query.c (can_atomic_load_p): New function.
* optabs-query.h (can_atomic_load_p): Declare it.
* optabs.c (expand_atomic_exchange): Always delegate to libatomic if
no fast atomic load is available for the particular size of access.
(expand_atomic_compare_and_swap): Likewise.
(expand_atomic_load): Likewise.
(expand_atomic_store): Likewise.
(expand_atomic_fetch_op): Likewise.
* testsuite/lib/target-supports.exp
(check_effective_target_sync_int_128): Remove x86 because it provides
no fast atomic load.
(check_effective_target_sync_int_128_runtime): Likewise.
libatomic/
* acinclude.m4: Add #define FAST_ATOMIC_LDST_*.
* auto-config.h.in: Regenerate.
* config/x86/host-config.h (FAST_ATOMIC_LDST_16): Define to 0.
(atomic_compare_exchange_n): New.
* glfree.c (EXACT, LARGER): Change condition and add comments.
From-SVN: r245098
