https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126293
--- Comment #16 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by H.J. Lu <[email protected]>: https://gcc.gnu.org/g:d9e21f7c4d1666baec96398f07ac500d1c912a12 commit r17-3230-gd9e21f7c4d1666baec96398f07ac500d1c912a12 Author: H.J. Lu <[email protected]> Date: Fri Jul 17 08:35:34 2026 +0800 x86-64: Add -m128bit-atomic With the silicon vendor guarantees from Intel, AMD, Hygon and Zhaoxin in: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104688 many software developers would happily use inline 128-bit atomic loads and stores in their programs because they only target compatible CPUs. Add -m128bit-atomic to generate 128-bit atomic loads and stores to avoid the overhead of calling into libatomic. Enable -m128bit-atomic in 64-bit mode by default if supported by the targeting processor, which is one of x86-64-v3 capable processors as well as AVX capable processors from Intel, AMD, Hygon and Zhaoxin. gcc/ PR target/94649 PR target/126293 * common/config/i386/i386-cpuinfo.h (ix86_decode_cpu_info): New function. * config/i386/i386-options.cc (ix86_option_override_internal): Issue an error for -m128bit-atomic in 32-bit mode. Turn on -mcx16 if -m128bit-atomic is enabled. Enable -m128bit-atomic in 64-bit mode by default if supported by the targeting processor. * config/i386/i386.h (TARGET_128BIT_ATOMIC_ENABLED): New. * config/i386/i386.opt (m128bit-atomic): New option. * config/i386/i386.opt.urls: Regenerated. * config/i386/sync.md: Update comments for 128-bit aligned vector loads and stores. (atomic_loadti): New pattern. (atomic_loadti_sse): Likewise. (atomic_storeti): Likewise. (atomic_storeti_sse): Likewise. * doc/invoke.texi: Remove __atomic Builtins reference from -mcx16. Document -m128bit-atomic. gcc/testsuite/ PR target/94649 PR target/126293 * g++.target/i386/pr94649-1.C: New test. * gcc.target/i386/pr126293-1a.c: Likewise. * gcc.target/i386/pr126293-1b.c: Likewise. * gcc.target/i386/pr126293-1c.c: Likewise. * gcc.target/i386/pr126293-1d.c: Likewise. * gcc.target/i386/pr126293-2a.c: Likewise. * gcc.target/i386/pr126293-2b.c: Likewise. * gcc.target/i386/pr126293-3a.c: Likewise. * gcc.target/i386/pr126293-3b.c: Likewise. * gcc.target/i386/pr126293-4a.c: Likewise. * gcc.target/i386/pr126293-4b.c: Likewise. * gcc.target/i386/pr126293-4c.c: Likewise. * gcc.target/i386/pr126293-4d.c: Likewise. * gcc.target/i386/pr126293-4e.c: Likewise. * gcc.target/i386/pr126293-4f.c: Likewise. * gcc.target/i386/pr126293-4g.c: Likewise. * gcc.target/i386/pr126293-4h.c: Likewise. * gcc.target/i386/pr126293-4i.c: Likewise. * gcc.target/i386/pr126293-4j.c: Likewise. * gcc.target/i386/pr126293-4k.c: Likewise. * gcc.target/i386/pr126293-4l.c: Likewise. * gcc.target/i386/pr126293-4m.c: Likewise. * gcc.target/i386/pr126293-4n.c: Likewise. * gcc.target/i386/pr126293-4o.c: Likewise. * gcc.target/i386/pr126293-4p.c: Likewise. * gcc.target/i386/pr126293-4q.c: Likewise. * gcc.target/i386/pr126293-4r.c: Likewise. * gcc.target/i386/pr126293-4s.c: Likewise. * gcc.target/i386/pr126293-5.c: Likewise. * gcc.target/i386/pr126293-6.c: Likewise. * gcc.target/i386/pr126293-7.c: Likewise. * gcc.target/i386/pr126293-8.c: Likewise. * gcc.target/i386/pr126293-9.c: Likewise. * gcc.target/i386/pr126293-10.c: Likewise. * gcc.target/i386/pr126293-11.c: Likewise. * gcc.target/i386/pr126293-12.c: Likewise. * gcc.target/i386/pr126293-13.c: Likewise. * gcc.target/i386/pr126293-14.c: Likewise. * gcc.target/i386/pr126293-15.c: Likewise. * gcc.target/i386/pr126293-16.c: Likewise. * gcc.target/i386/pr126293-17.c: Likewise. Signed-off-by: H.J. Lu <[email protected]>
