gcc/ChangeLog: * collect2.cc (main): Add wild linker to -fuse-ld. * common.opt: Likewise. * configure: Regenerate. * configure.ac: Add detection for wild linker. * doc/invoke.texi: Document -fuse-ld=wild. * gcc.cc (driver_handle_option): Support -fuse-ld=wild. * opts.cc (common_handle_option): Likewise. libatomic/ChangeLog: * acinclude.m4: Add detection for wild linker. * configure: Regenerate. libgomp/ChangeLog: * acinclude.m4:: Add detection for wild linker. * configure: Regenerate. libitm/ChangeLog: * acinclude.m4:: Add detection for wild linker. * configure: Regenerate. libstdc++-v3/ChangeLog: * acinclude.m4:: Add detection for wild linker. * configure: Regenerate. Signed-off-by: Martin Liška <martin.liska@hey.com>
As [1] says, we cannot mix up lock-free and locking atomics for one
object. For example assume atom = (0, 0) initially, if we have a
locking "atomic" xor running on T0 and a lock-free store running on T1
concurrently:
T0 | T1
-----------------------------+-------------------------------------
acquire_lock |
t0 = atom[0] |
/* some CPU cycles */ | atom = (1, 1) /* lock-free atomic */
t1 = atom[1] |
t0 ^= 1 |
t1 ^= 1 |
atom[0] = t0 |
atom[1] = t1 |
release_lock |
we get atom = (0, 1), but the atomicity of xor and store should
guarantee that atom is either (0, 0) or (1, 1).
So, if we want to use a lock-free 16B atomic operation, we need both LSX
and SCQ even if that specific operation only needs one of them. To make
things worse, one may link a TU compiled with -mlsx -mscq and another
without them together, then if we want to use the lock-free 16B atomic
operations in the former, we must make libatomic also use the lock-free
16B atomic operation for the latter so we need to add ifuncs for
libatomic, similar to the discussion about i386 vs. i486 in [1].
Implementing and building the ifuncs currently requires:
- Glibc, because the ifunc resolver interface is libc-specific
- Linux, because the HWCAP bit for LSX is kernel-specific
- A recent enough assembler at build time to recognize sc.q
So the approach here is: only allow 16B lock-free atomic operations in
the compiler if the criteria above is satisfied, and ensure libatomic to
use those lock-free operations on capable hardware (via ifunc unless
both LSX and SCQ are already enabled by the builder) if the compiler
allows 16B lock-free atomic.
[1]: https://gcc.gnu.org/wiki/Atomic/GCCMM/LIbrary
gcc/
* configure.ac (HAVE_AS_16B_ATOMIC): Define if the assembler
supports LSX and sc.q.
* configure: Regenerate.
* config.in: Regenerate.
* config/loongarch/loongarch-opts.h (HAVE_AS_16B_ATOMIC):
Defined to 0 if undefined yet.
* config/loongarch/linux.h (HAVE_IFUNC_FOR_LIBATOMIC_16B):
Define as HAVE_AS_16B_ATOMIC && OPTION_GLIBC.
* config/loongarch/loongarch-protos.h
(loongarch_16b_atomic_lock_free_p): New prototype.
* config/loongarch/loongarch.cc
(loongarch_16b_atomic_lock_free_p): Implement.
* config/loongarch/sync.md (atomic_storeti_lsx): Require
loongarch_16b_atomic_lock_free_p.
(atomic_storeti): Likewise.
(atomic_exchangeti_scq): Likewise.
(atomic_exchangeti): Likewise.
(atomic_compare_and_swapti): Likewise.
(atomic_fetch_<amop_ti_fetch>ti_scq): Likewise.
(atomic_fetch_<amop_ti_fetch>ti): Likewise.
(ALL_SC): Likewise for TImode.
(atomic_storeti_scq): Remove.
libatomic/
* configure.ac (ARCH_LOONGARCH): New AM_CONDITIONAL.
* Makefile.am (IFUNC_OPT): Separate the item from IFUNC_OPTIONS
to allow using multiple options for an ISA variant.
(libatomic_la_LIBADD): Add *_16_1_.lo for LoongArch.
(IFUNC_OPTIONS): Build *_16_1_.lo for LoongArch with -mlsx and
-mscq.
* configure: Regenerate.
* Makefile.in: Regenerate.
* configure.tgt (try_ifunc): Set to yes for LoongArch if the
compiler can produce lock-free 16B atomic with -mlsx -mscq.
* config/loongarch/host-config.h: Implement ifunc selector.
This just pulls in Alan's:
commit 87b6078fc212ccba5f043399c6370ee20f6b355a
Author: Alan Modra <amodra@gmail.com>
AuthorDate: Mon Nov 3 10:59:50 2025 +1030
Commit: Alan Modra <amodra@gmail.com>
CommitDate: Mon Nov 3 10:59:50 2025 +1030
tidy m4 plugin config support
...
It tidies up the configure test output.
config/ChangeLog:
* clang-plugin.m4: Sync with binutils.
* gcc-plugin.m4: Ditto.
ChangeLog:
* configure: Regenerate.
gcc/ChangeLog:
* configure: Regenerate.
libatomic/ChangeLog:
* configure: Regenerate.
libbacktrace/ChangeLog:
* configure: Regenerate.
libcc1/ChangeLog:
* configure: Regenerate.
libffi/ChangeLog:
* configure: Regenerate.
libgcobol/ChangeLog:
* configure: Regenerate.
libgfortran/ChangeLog:
* configure: Regenerate.
libgm2/ChangeLog:
* configure: Regenerate.
libgomp/ChangeLog:
* configure: Regenerate.
libgrust/ChangeLog:
* configure: Regenerate.
libiberty/ChangeLog:
* configure: Regenerate.
libitm/ChangeLog:
* configure: Regenerate.
libobjc/ChangeLog:
* configure: Regenerate.
libphobos/ChangeLog:
* configure: Regenerate.
libquadmath/ChangeLog:
* configure: Regenerate.
libsanitizer/ChangeLog:
* configure: Regenerate.
libssp/ChangeLog:
* configure: Regenerate.
libstdc++-v3/ChangeLog:
* configure: Regenerate.
libvtv/ChangeLog:
* configure: Regenerate.
lto-plugin/ChangeLog:
* configure: Regenerate.
zlib/ChangeLog:
* configure: Regenerate.
ChangeLog: PR driver/81358 * Makefile.def: Add no_atomic=true for libraries that don't depend on libatomic. * Makefile.tpl: Export TARGET_CONFIGDIRS and create rule to add dependencies for libatomic. * configure.ac: Add libatomic to bootstrap_target_libs. * Makefile.in: Regenerate. * configure: Regenerate. gcc/ChangeLog: PR driver/81358 * common.opt: New option -flink-libatomic. * gcc.cc (LINK_LIBATOMIC_SPEC): New macro. * config/alpha/linux.h (LINK_GCC_C_SEQUENCE_SPEC): Use LINK_LIBATOMIC_SPEC. * config/arm/uclinux-elf.h: Likewise. * config/arm/unknown-elf.h: Likewise. * config/avr/avrlibc.h: Likewise. * config/bfin/linux.h: Likewise. * config/darwin.h: Likewise. * config/gnu-user.h: Likewise. * config/lm32/uclinux-elf.h: Likewise. * config/rs6000/linux64.h: Likewise. * config/rs6000/rtems.h: Likewise. * config/sparc/sparc.h: Likewise. * doc/invoke.texi: Document -flink-libatomic. * configure.ac: Define TARGET_PROVIDES_LIBATOMIC. * configure: Regenerate. * config.in: Regenerate. * common.opt.urls: Regenerate. libatomic/ChangeLog: PR driver/81358 * Makefile.am: Pass -fno-link-libatomic. New rule all-local. * configure.ac: Assert that CFLAGS is set and pass -fno-link-libatomic. Use __libatomic_save_CFLAGS__ instead of save_CFLAGS. * Makefile.in: Regenerate. * configure: Regenerate. Signed-off-by: Prathamesh Kulkarni <prathameshk@nvidia.com> Co-authored-by: Matthew Malcolmson <mmalcolmson@nvidia.com>
libatomic/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * testsuite/Makefile.in: Regenerate. libcc1/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. libffi/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * include/Makefile.in: Regenerate. * man/Makefile.in: Regenerate. * testsuite/Makefile.in: Regenerate. libgcobol/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. libgfortran/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. libgm2/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * libm2cor/Makefile.in: Regenerate. * libm2iso/Makefile.in: Regenerate. * libm2log/Makefile.in: Regenerate. * libm2min/Makefile.in: Regenerate. * libm2pim/Makefile.in: Regenerate. libgomp/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * testsuite/Makefile.in: Regenerate. libgrust/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * libformat_parser/Makefile.in: Regenerate. * libproc_macro_internal/Makefile.in: Regenerate. libitm/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * testsuite/Makefile.in: Regenerate. libobjc/ChangeLog: * aclocal.m4: Regenerate. * configure: Regenerate. libphobos/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * libdruntime/Makefile.in: Regenerate. * src/Makefile.in: Regenerate. * testsuite/Makefile.in: Regenerate. libquadmath/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. libsanitizer/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * asan/Makefile.in: Regenerate. * configure: Regenerate. * hwasan/Makefile.in: Regenerate. * interception/Makefile.in: Regenerate. * libbacktrace/Makefile.in: Regenerate. * lsan/Makefile.in: Regenerate. * sanitizer_common/Makefile.in: Regenerate. * tsan/Makefile.in: Regenerate. * ubsan/Makefile.in: Regenerate. libssp/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. libstdc++-v3/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * doc/Makefile.in: Regenerate. * include/Makefile.in: Regenerate. * libsupc++/Makefile.in: Regenerate. * po/Makefile.in: Regenerate. * python/Makefile.in: Regenerate. * src/Makefile.in: Regenerate. * src/c++11/Makefile.in: Regenerate. * src/c++17/Makefile.in: Regenerate. * src/c++20/Makefile.in: Regenerate. * src/c++23/Makefile.in: Regenerate. * src/c++26/Makefile.in: Regenerate. * src/c++98/Makefile.in: Regenerate. * src/experimental/Makefile.in: Regenerate. * src/filesystem/Makefile.in: Regenerate. * src/libbacktrace/Makefile.in: Regenerate. * testsuite/Makefile.in: Regenerate. libvtv/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate. * testsuite/Makefile.in: Regenerate. lto-plugin/ChangeLog: * Makefile.in: Regenerate. * aclocal.m4: Regenerate. * configure: Regenerate.