Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_add.3 was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_add_16_cas.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_add_16_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.9.24;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.8.2;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Fix up the remaining __sync_* functions to build with Clang on ARM.

Rework so that __sync_fetch_and_<OP>_<N> actually returns a value.

Add __sync_fetch_and_add_4 alias

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_add_32_cas.c was initially added on branch thorpej-atomic.

Put back the weak-alias into the user namespace that was accidentally
deleted in last commit.

atomic_add_ptr_nv(): Don't use a symbol alias. Pointer values may have
a different return convention than integer values (m68k falls into this
category -- pointer values are returned in %a0 in addition to %d0).

branches: 1.7.16;
Include the C11 atomic builtin alias.

Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add __sync_<OP>_and_fetch_<N> aliases

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_add_32_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.9.24;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.8.2;
Allow building with clang.
XXX __RENAME is currently not allowed for the kernel, so use plain asm.
Clang rejects definitions of builtins, so it doesn't work without.

Rework so that __sync_fetch_and_<OP>_<N> actually returns a value.

Add __sync_fetch_and_add_8 alias

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_add_64_cas.c was initially added on branch thorpej-atomic.

Put back the weak-alias into the user namespace that was accidentally
deleted in last commit.

atomic_add_ptr_nv(): Don't use a symbol alias. Pointer values may have
a different return convention than integer values (m68k falls into this
category -- pointer values are returned in %a0 in addition to %d0).

branches: 1.7.26;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add __sync_<OP>_and_fetch_<N> aliases

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_add_64_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_add_8_cas.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_add_8_nv_cas.c was initially added on branch thorpej-atomic.

Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_and.3 was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_and_16_cas.c was initially added on branch thorpej-atomic.

branches: 1.2.2; 1.2.18;
Provide __sync_and_and_fetch_2 and __sync_and_and_fetch_1 for pre-ARMv6,
they are needed for the C++ 2011 <atomic> stuff.

branches: 1.1.2;
file atomic_and_16_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.10.24;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.9.2;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Fix up the remaining __sync_* functions to build with Clang on ARM.

fix tpyos.

Rework so that __sync_fetch_and_<OP>_<N> actually returns a value.

Add __sync_fetch_and_<OP>_<N> aliases

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_and_32_cas.c was initially added on branch thorpej-atomic.

branches: 1.7.26;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Fix tpyo (add->and)

Add __sync_<OP>_and_fetch_<N> aliases

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_and_32_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.10.24;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.9.2;
Allow building with clang.
XXX __RENAME is currently not allowed for the kernel, so use plain asm.
Clang rejects definitions of builtins, so it doesn't work without.

Return old

Rework so that __sync_fetch_and_<OP>_<N> actually returns a value.

Add __sync_fetch_and_<OP>_<N> aliases

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_and_64_cas.c was initially added on branch thorpej-atomic.

Fix typo; this is "and", not "add".

branches: 1.7.26;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add __sync_<OP>_and_fetch_<N> aliases

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_and_64_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_and_8_cas.c was initially added on branch thorpej-atomic.

branches: 1.2.2; 1.2.18;
Provide __sync_and_and_fetch_2 and __sync_and_and_fetch_1 for pre-ARMv6,
they are needed for the C++ 2011 <atomic> stuff.

branches: 1.1.2;
file atomic_and_8_nv_cas.c was initially added on branch thorpej-atomic.

sprinkle argsused

*** empty log message ***

make some prototypes match the builtin properly. GCC 9 complains
with the old version, GCC 8 is happy with this version.

tested on sparc.

branches: 1.2.2; 1.2.18; 1.2.20;
Provide prototypes to fix build with clang.

Provide __atomic_compare_exchange_N (as needed for the C11 2011 <atomic>
ops) via the corresponding CAS.

sprinkle argsused

Fix the copy&paste botch from previous. Spotted by Tom Lane.

*** empty log message ***

make some prototypes match the builtin properly. GCC 9 complains
with the old version, GCC 8 is happy with this version.

tested on sparc.

branches: 1.2.2; 1.2.18; 1.2.20;
Provide prototypes to fix build with clang.

Provide __atomic_compare_exchange_N (as needed for the C11 2011 <atomic>
ops) via the corresponding CAS.

sprinkle argsused

*** empty log message ***

make some prototypes match the builtin properly. GCC 9 complains
with the old version, GCC 8 is happy with this version.

tested on sparc.

branches: 1.2.2; 1.2.18; 1.2.20;
Provide prototypes to fix build with clang.

Provide __atomic_compare_exchange_N (as needed for the C11 2011 <atomic>
ops) via the corresponding CAS.

Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_cas.3 was initially added on branch thorpej-atomic.

branches: 1.3.6; 1.3.28;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_cas_16_cas.c was initially added on branch thorpej-atomic.

branches: 1.1.4; 1.1.8; 1.1.30;
Provide 32bit __sync ops based on atomic_cas_32.

branches: 1.2.4; 1.2.8; 1.2.30;
Do not include <stdbool.h> in the kernel

Provide most missing __sync_*64 primitives for i386

branches: 1.3.6; 1.3.28;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_cas_8_cas.c was initially added on branch thorpej-atomic.

branches: 1.4.16;
Add __sync_val_compare_and_swap_{1,2} aliases for _atomic_cas_{8,16}

branches: 1.3.4; 1.3.6; 1.3.8;
Fix subword atomic_cas.

- Don't loop forever on failure.
- Don't shift away the result and return zero on success.

Evidently we lack automatic tests for these!

Fix return value (typo, noticed by Nick Hudson)

Provide cas_16 and cas_8 emulation via cas_32 and use that for mips64

Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_dec.3 was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_dec_16_add.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_dec_16_nv_add.c was initially added on branch thorpej-atomic.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_dec_32_add.c was initially added on branch thorpej-atomic.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_dec_32_nv_add.c was initially added on branch thorpej-atomic.

atomic_{inc,dec}_ptr_nv(): Don't use a symbol alias. Pointer values may
have a different return convention than integer values (m68k falls into
this category -- pointer values are returned in %a0 in addition to %d0).

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.4.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_dec_64_add.c was initially added on branch thorpej-atomic.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.4.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_dec_64_nv_add.c was initially added on branch thorpej-atomic.

atomic_{inc,dec}_ptr_nv(): Don't use a symbol alias. Pointer values may
have a different return convention than integer values (m68k falls into
this category -- pointer values are returned in %a0 in addition to %d0).

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.1.2;
file atomic_dec_8_add.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_dec_8_nv_add.c was initially added on branch thorpej-atomic.

Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_inc.3 was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_inc_16_add.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_inc_16_nv_add.c was initially added on branch thorpej-atomic.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_inc_32_add.c was initially added on branch thorpej-atomic.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_inc_32_nv_add.c was initially added on branch thorpej-atomic.

atomic_{inc,dec}_ptr_nv(): Don't use a symbol alias. Pointer values may
have a different return convention than integer values (m68k falls into
this category -- pointer values are returned in %a0 in addition to %d0).

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.4.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_inc_64_add.c was initially added on branch thorpej-atomic.

branches: 1.3.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.4.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_inc_64_nv_add.c was initially added on branch thorpej-atomic.

atomic_{inc,dec}_ptr_nv(): Don't use a symbol alias. Pointer values may
have a different return convention than integer values (m68k falls into
this category -- pointer values are returned in %a0 in addition to %d0).

branches: 1.4.64;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Correct what must obviously be a cut+paste-induced set of typos.

atomic_add_* takes signed integers, the others take unsigned.

Add inc/dec variants that use atomic_cas in preference to atomic_add.

branches: 1.1.2;
file atomic_inc_8_add.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_inc_8_nv_add.c was initially added on branch thorpej-atomic.

make decls consistent

branches: 1.4.26;
Use __section(".test.startup") for the init routines

branches: 1.3.4; 1.3.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.6;
Fix name of the init function.

Some glue for atomic ops in userspace.

Catch up with revision 1.5 of atomic_init_cas.c. Fixes building libc
on sun2, and probably others.

make decls consistent

PR 55239: initialize all RAS sections for non-MP configurations

Add some atomic_cas_64_ni aliases

branches: 1.15.26;
Add atomic_cas_64 support for ARM EABI on V5TE and V5TEJ cpus.
(strd is atomic).

Provide CAS variants for 16 and 8 bit when running with more that 1 cpu

Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Fix a few more copy&pastos - now it actually builds.

Fix copy&pasto

Add _atomic_cas_16 and _atomic_cas_8 and their aliases
__sync_val_compare_and_swap_2 & __sync_val_compare_and_swap_1

Use __section(".test.startup") for the init routines

branches: 1.8.2;
Make sure to create the right aliases.

branches: 1.7.6;
Merge from matt-nb5-mips64

Make sure _atomic_cas_fn is initialised for "weirdo environments" such
as ramdisks where the constructor doesn't get called.

Fixes ifconfig in hp700 sysinst.

OK'ed by ad.

branches: 1.5.10;
Implement _atomic_cas_up() in assembly code as the compiler cannot be
trusted to generate fully restartable code sequences.

Addresses lib/38482 for ARM and m68000.

Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.6;
Put back a __predict_false removed during testing and fix atomic_cas_mp().

Add atomic_cas_foo_ni().

Some glue for atomic ops in userspace.

branches: 1.3.2;
libc atomic: Make previous work a little less accidentally.

libc __atomic_is_lock_free: Fix clang build with symbol hacks.

libc: Define __atomic_is_lock_free.

Limited to architectures where it is actually needed by gcc for any
calls to stdatomic.h atomic_is_lock_free for now.

We should also add it to other architectures too, along with lockful
atomic r/m/w operations for sizes that can't be handled natively, but
that's a lot more work. It is also necessary for -fno-inline-atomics
but we're missing a lot of other symbols for that too, to be fixed.
For now, this should enable the OpenSSL build to complete on these
architectures again after I reverted a local change.

XXX pullup-10

sprinkle unused.

libc/atomic: Fix membars in __atomic_load/store_* stubs.

- membar_enter/exit ordering was backwards.
- membar_enter doesn't make any sense for load anyway.
- Switch to membar_release for store and membar_acquire for load.

The only sensible orderings for a simple load or store are acquire or
release, respectively, or sequential consistency. This never
provided correct sequential consistency before -- we should really
make it conditional on memmodel but I don't know offhand what the
values of memmodel might be and this is at least better than before.

make some prototypes match the builtin properly. GCC 9 complains
with the old version, GCC 8 is happy with this version.

tested on sparc.

branches: 1.2.2; 1.2.6; 1.2.28;
Add unused memory model argument to make GCC happy.

Provide a basic implementation of __atomic_load_* and __atomic_store_*,
used by GCC and LLVM as backing for C11/C++11 atomics, if the hardware
is not known to have corresponding features. Include it on ARM as LLVM
and libc++ hit it when compiled for ARMv4.

Add missing alias for __atomic_fetch_nand_N.
XXX I'm not sure why does llvm/sparc call __atomic instead of
__sync though.
XXX atomic_*_cas.c should be more symmetric...

branches: 1.2.4; 1.2.8; 1.2.30;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

Add missing alias for __atomic_fetch_nand_N.
XXX I'm not sure why does llvm/sparc call __atomic instead of
__sync though.
XXX atomic_*_cas.c should be more symmetric...

branches: 1.1.4; 1.1.8; 1.1.30;
Provide 32bit __sync ops based on atomic_cas_32.

branches: 1.2.4; 1.2.8; 1.2.30;
Make the _and_fetch_8 primitives return the new value they calculated
and set - not whatever is found in memory later.

Provide most missing __sync_*64 primitives for i386

Add missing alias for __atomic_fetch_nand_N.
XXX I'm not sure why does llvm/sparc call __atomic instead of
__sync though.
XXX atomic_*_cas.c should be more symmetric...

branches: 1.2.4; 1.2.8; 1.2.30;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2;
file atomic_op_cas_impl.h was initially added on branch thorpej-atomic.

libc atomic_op_namespace.h: Add membar_release and membar_acquire.

These namespace macros will be needed so that libpthread can call
NetBSD's nonstandard membar_release/acquire functions even if linked
against an application that defines symbols of the same name.

Preparation for:

PR lib/59126: pthread_once(3): missing memory ordering

branches: 1.7.16; 1.7.36;
Provide __sync_and_and_fetch_2 and __sync_and_and_fetch_1 for pre-ARMv6,
they are needed for the C++ 2011 <atomic> stuff.

branches: 1.6.4;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.4.2; 1.4.24;
+atomic_cas_*_ni

branches: 1.3.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_op_namespace.h was initially added on branch thorpej-atomic.

Install manual pages for the atomic ops.

branches: 1.5.2;
Convert TNF licenses to new 2 clause variant

branches: 1.4.4;
Note many of the restrictions, and clarify the section on global
visibility.

branches: 1.3.4;
Typo fixes.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_ops.3 was initially added on branch thorpej-atomic.

Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_or.3 was initially added on branch thorpej-atomic.

Fix return value. or_and_fetch should return new value.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_or_16_cas.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_or_16_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.10.24;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.9.2;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Fix up the remaining __sync_* functions to build with Clang on ARM.

fix tpyos.

Rework so that __sync_fetch_and_<OP>_<N> actually returns a value.

Add __sync_fetch_and_<OP>_<N> aliases

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_or_32_cas.c was initially added on branch thorpej-atomic.

branches: 1.6.26;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add __sync_<OP>_and_fetch_<N> aliases

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_or_32_nv_cas.c was initially added on branch thorpej-atomic.

branches: 1.10.24;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.9.2;
Allow building with clang.
XXX __RENAME is currently not allowed for the kernel, so use plain asm.
Clang rejects definitions of builtins, so it doesn't work without.

fix c&p bug.

Rework so that __sync_fetch_and_<OP>_<N> actually returns a value.

Add __sync_fetch_and_<OP>_<N> aliases

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_or_64_cas.c was initially added on branch thorpej-atomic.

branches: 1.7.26;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add __sync_<OP>_and_fetch_<N> aliases

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_or_64_nv_cas.c was initially added on branch thorpej-atomic.

Fix return value. or_and_fetch should return new value.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_or_8_cas.c was initially added on branch thorpej-atomic.

branches: 1.1.2;
file atomic_or_8_nv_cas.c was initially added on branch thorpej-atomic.

mark unused argument

libc/atomic: Fix membars in __atomic_load/store_* stubs.

- membar_enter/exit ordering was backwards.
- membar_enter doesn't make any sense for load anyway.
- Switch to membar_release for store and membar_acquire for load.

The only sensible orderings for a simple load or store are acquire or
release, respectively, or sequential consistency. This never
provided correct sequential consistency before -- we should really
make it conditional on memmodel but I don't know offhand what the
values of memmodel might be and this is at least better than before.

make some prototypes match the builtin properly. GCC 9 complains
with the old version, GCC 8 is happy with this version.

tested on sparc.

branches: 1.2.2; 1.2.6; 1.2.28;
Add unused memory model argument to make GCC happy.

Provide a basic implementation of __atomic_load_* and __atomic_store_*,
used by GCC and LLVM as backing for C11/C++11 atomics, if the hardware
is not known to have corresponding features. Include it on ARM as LLVM
and libc++ hit it when compiled for ARMv4.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2; 1.2.4;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.2.4; 1.2.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.1.2; 1.1.4;
Provide 32bit __sync ops based on atomic_cas_32.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2; 1.2.4;
Make the _and_fetch_8 primitives return the new value they calculated
and set - not whatever is found in memory later.

Provide most missing __sync_*64 primitives for i386

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2; 1.2.4;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

Install manual pages for the atomic ops.

branches: 1.3.2;
Convert TNF licenses to new 2 clause variant

branches: 1.2.4; 1.2.8;
Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_swap.3 was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the C11/C++11 spelling of the CAS primitives.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_swap_16_cas.c was initially added on branch thorpej-atomic.

branches: 1.7.24;
Add aliases for the C11/C++11 spelling of the CAS primitives.

branches: 1.6.2;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add missing __sync_lock_test_and_set_* aliases for PR lib/48601

branches: 1.4.4; 1.4.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_swap_32_cas.c was initially added on branch thorpej-atomic.

One more typo; this is called _atomic_swap_64, not _8.

branches: 1.9.24;
Add aliases for the C11/C++11 spelling of the CAS primitives.

branches: 1.8.2;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Fix previous: move the alias declaration outside of a #ifdef _LP64

Add missing __sync_lock_test_and_set_* aliases for PR lib/48601

branches: 1.5.4; 1.5.26;
Remove clause 3 and 4 from TNF licenses

branches: 1.4.4; 1.4.8;
Only build the 64-bit versions if __HAVE_ATOMIC64_OPS.

Memory barrier in respect of the CAS isn't necessary.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file atomic_swap_64_cas.c was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the C11/C++11 spelling of the CAS primitives.

branches: 1.2.2;
Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.1.2; 1.1.24;
file atomic_swap_8_cas.c was initially added on branch thorpej-atomic.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2; 1.2.4;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

branches: 1.2.4; 1.2.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.1.2; 1.1.4;
Provide 32bit __sync ops based on atomic_cas_32.

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2; 1.2.4;
Make the _and_fetch_8 primitives return the new value they calculated
and set - not whatever is found in memory later.

Provide most missing __sync_*64 primitives for i386

branches: 1.3.4; 1.3.26;
Add aliases for the builtins used to implement C11/C++11 atomics.

branches: 1.2.2; 1.2.4;
Add a few missing namespace includes

Provide 8 and 16 bit sync ops (using 16 bit and 8 bit cas)

Install manual pages for the atomic ops.

branches: 1.5.2;
Convert TNF licenses to new 2 clause variant

branches: 1.4.4;
Clarify what membar_enter/membar_exit provide.

branches: 1.3.4;
Typo fixes.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file membar_ops.3 was initially added on branch thorpej-atomic.

Introduce membar_acquire/release. Deprecate membar_enter/exit.

The names membar_enter/exit were unclear, and the documentation of
membar_enter has disagreed with the implementations on sparc,
powerpc, and even x86(!) for the entire time it has been in NetBSD.

The terms `acquire' and `release' are ubiquitous in the literature
today, and have been adopted in the C and C++ standards to mean
load-before-load/store and load/store-before-store, respectively,
which are exactly the orderings required by acquiring and releasing a
mutex, as well as other useful applications like decrementing a
reference count and then freeing the underlying object if it went to
zero.

Originally I proposed changing one word in the documentation for
membar_enter to make it load-before-load/store instead of
store-before-load/store, i.e., to make it an acquire barrier. I
proposed this on the grounds that

(a) all implementations guarantee load-before-load/store,
(b) some implementations fail to guarantee store-before-load/store,
and
(c) all uses in-tree assume load-before-load/store.

I verified parts (a) and (b) (except, for (a), powerpc didn't even
guarantee load-before-load/store -- isync isn't necessarily enough;
need lwsync in general -- but it _almost_ did, and it certainly didn't
guarantee store-before-load/store).

Part (c) might not be correct, however: under the mistaken assumption
that atomic-r/m/w then membar-w/rw is equivalent to atomic-r/m/w then
membar-r/rw, I only audited the cases of membar_enter that _aren't_
immediately after an atomic-r/m/w. All of those cases assume
load-before-load/store. But my assumption was wrong -- there are
cases of atomic-r/m/w then membar-w/rw that would be broken by
changing to atomic-r/m/w then membar-r/rw:

https://mail-index.netbsd.org/tech-kern/2022/03/29/msg028044.html

Furthermore, the name membar_enter has been adopted in other places
like OpenBSD where it actually does follow the documentation and
guarantee store-before-load/store, even if that order is not useful.
So the name membar_enter currently lives in a bad place where it
means either of two things -- r/rw or w/rw.

With this change, we deprecate membar_enter/exit, introduce
membar_acquire/release as better names for the useful pair (r/rw and
rw/w), and make sure the implementation of membar_enter guarantees
both what was documented _and_ what was implemented, making it an
alias for membar_sync.

While here, rework all of the membar_* definitions and aliases. The
new logic follows a rule to make it easier to audit:

membar_X is defined as an alias for membar_Y iff membar_X is
guaranteed by membar_Y.

The `no stronger than' relation is (the transitive closure of):

- membar_consumer (r/r) is guaranteed by membar_acquire (r/rw)
- membar_producer (w/w) is guaranteed by membar_release (rw/w)
- membar_acquire (r/rw) is guaranteed by membar_sync (rw/rw)
- membar_release (rw/w) is guaranteed by membar_sync (rw/rw)

And, for the deprecated membars:

- membar_enter (whether r/rw, w/rw, or rw/rw) is guaranteed by
membar_sync (rw/rw)
- membar_exit (rw/w) is guaranteed by membar_release (rw/w)

(membar_exit is identical to membar_release, but the name is
deprecated.)

Finally, while here, annotate some of the instructions with their
semantics. For powerpc, leave an essay with citations on the
unfortunate but -- as far as I can tell -- necessary decision to use
lwsync, not isync, for membar_acquire and membar_consumer.

Also add membar(3) and atomic(3) man page links.

branches: 1.7.26;
Try to hide the C runtime implementation specific __sync_* ops from librump,
to avoid duplicates.

Add __sync_synchronize alias.

branches: 1.5.6; 1.5.12;
__strong_alias(foo,foo) is... pointless.

branches: 1.4.12;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.4; 1.3.8;
membar_read/write are gone.

Support files from the thorpej-atomic branch.

branches: 1.1.2;
file membar_ops_nop.c was initially added on branch thorpej-atomic.