Use asm implements for i386/x86_64/arm/aarch64/riscv:
__atomic_load_[1,2,4,8]
__atomic_store_[1,2,4,8]
__atomic_compare_exchange_[1,2,4,8]
__atomic_test_and_set_[1,2,4,8]
atomic_thread_fence
atomic_signal_fence
atomic_flag_test_and_set
atomic_flag_test_and_set_explicit
atomic_flag_clear
atomic_flag_clear_explicit
`atomic.S` is extracted from `gcc` v15.1.0 `libatomic.a`.
And generated by https://github.com/kbkpbot/gen_atomic.git
This commit adds GCC-compatible atomic builtins to stdatomic.h for
better compatibility with code relying on GCC's atomic primitives.
1. **New Macros**:
- `__atomic_compare_exchange_n`.
- `__atomic_load_n`.
- `__atomic_store_n`.
2. **Motivation**:
- Improves compatibility with codebases using GCC's atomic builtins
directly.
- Simplifies atomic operations by allowing direct value passing
(instead of pointers), enhancing code readability.
- Aligns TCC's atomic support closer to GCC/Clang for cross-compiler
projects.
3. **Testing**:
- Verified with basic test cases (integer CAS, load/store) on x86.
- Confirmed no regressions in existing atomic operations.
- This change does not affect existing C11 `atomic_*` APIs.
- Struct types are intentionally unsupported in `_n` variants due to
complexity.
The __atomic_test_and_set and __atomic_clear code was correct.
They needed locking.
Replaced to code with assembly code.
The changes are in include/stdatomic.h, lib/stdatomic.c, lib/atomic.S
Enabled tests/tests2/124_atomic_counter.c for apple again.
Also moved lib/fetch_and_add.S code to lib/atomic.S.
Removed lib/fetch_and_add.S
Adjusted lib/Makefile
Make code more compatible with gcc. Change
__atomic_store
__atomic_load
__atomic_exchange
__atomic_compare_exchange
Also add (include/stdatomic.h, lib/stdatomic.c):
atomic_thread_fence
atomic_signal_fence
atomic_is_lock_free
And gcc extensions (tcctok.h, tccgen.c, lib/stdatomic.c):
__atomic_fetch_nand
__atomic_and_fetch
__atomic_sub_fetch
__atomic_or_fetch
__atomic_xor_fetch
__atomic_and_fetch
__atomic_nand_fetch
Add new file lib/atomic.S with assembly code for __atomic_compare_exchange_n
for arm/arm64/riscv. Also update lib/Makefile.
Update testcode in 124_atomic_counter and 125_atomic_misc to test new functions.
Also update tests/tests2/Makefile to run tests on arm/arm64/riscv.
- remove any error messages that were just for debugging the
templates really
- don't use c99 in tcc (array designators etc.)
- remove memory model type (cannot be an own type really)
and move memory model defines from built-in to stdatomics.h
- apply normal casts to non-pointer atomic_function arguments
- tidy the library support
- add some tests for errors/warnings
Also:
- Makefile: move GIT_HASH stuff from CFLAGS to DEFINES and into
main section (away from what is included by tests for example)
- tccelf.c/tccgen.c: avoid some warnings with newer GCC
