diff options
Diffstat (limited to 'gnu/llvm/compiler-rt/lib/builtins/atomic.c')
| -rw-r--r-- | gnu/llvm/compiler-rt/lib/builtins/atomic.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/gnu/llvm/compiler-rt/lib/builtins/atomic.c b/gnu/llvm/compiler-rt/lib/builtins/atomic.c index 64bf72dfa34..852bb20f086 100644 --- a/gnu/llvm/compiler-rt/lib/builtins/atomic.c +++ b/gnu/llvm/compiler-rt/lib/builtins/atomic.c @@ -92,6 +92,8 @@ __inline static void lock(Lock *l) { OSSpinLockLock(l); } static Lock locks[SPINLOCK_COUNT]; // initialized to OS_SPINLOCK_INIT which is 0 #else +_Static_assert(__atomic_always_lock_free(sizeof(uintptr_t), 0), + "Implementation assumes lock-free pointer-size cmpxchg"); typedef _Atomic(uintptr_t) Lock; /// Unlock a lock. This is a release operation. __inline static void unlock(Lock *l) { @@ -336,6 +338,18 @@ OPTIMISED_CASES return tmp; \ } +#define ATOMIC_RMW_NAND(n, lockfree, type) \ + type __atomic_fetch_nand_##n(type *ptr, type val, int model) { \ + if (lockfree(ptr)) \ + return __c11_atomic_fetch_nand((_Atomic(type) *)ptr, val, model); \ + Lock *l = lock_for_pointer(ptr); \ + lock(l); \ + type tmp = *ptr; \ + *ptr = ~(tmp & val); \ + unlock(l); \ + return tmp; \ + } + #define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, add, +) OPTIMISED_CASES #undef OPTIMISED_CASE @@ -351,3 +365,9 @@ OPTIMISED_CASES #define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, xor, ^) OPTIMISED_CASES #undef OPTIMISED_CASE +// Allow build with clang without __c11_atomic_fetch_nand builtin (pre-14) +#if __has_builtin(__c11_atomic_fetch_nand) +#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW_NAND(n, lockfree, type) +OPTIMISED_CASES +#undef OPTIMISED_CASE +#endif |