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- #define ASM_DMB_ISH "dmb ish\n\t"
- #if defined(__ARM_ARCH_7S__)
- // this is sufficient for Swift processors
- # define ASM_REL "dmb ishst\n\t"
- #else
- # define ASM_REL "dmb ish\n\t"
- #endif
- static inline void atomic_pause()
- {
- }
- static inline void atomic_thread_fence(memory_order_relaxed_t)
- {
- }
- static inline void atomic_thread_fence(memory_order_acquire_t)
- {
- __asm__ __volatile__ ("dmb ld\n\t" : : : "memory");
- }
- static inline void atomic_thread_fence(memory_order_release_t)
- {
- __asm__ __volatile__ (ASM_REL : : : "memory");
- }
- static inline void atomic_thread_fence(memory_order_acq_rel_t)
- {
- __asm__ __volatile__ (ASM_DMB_ISH : : : "memory");
- }
- static inline void atomic_thread_fence(int /* memory_order_seq_cst_t */)
- {
- __asm__ __volatile__ (ASM_DMB_ISH : : : "memory");
- }
- #define ATOMIC_LOAD(opc) \
- atomic_word res; \
- __asm__ __volatile__ \
- ( \
- opc " %0, %1\n\t" \
- : "=r" (res) \
- : "m" (*p) \
- ); \
- return res;
- /*
- * int support
- */
- static inline int atomic_load_explicit(const volatile int* p, memory_order_relaxed_t)
- {
- int res;
- __asm__ __volatile__
- (
- "ldr %w0, %w1\n\t"
- : "=r" (res)
- : "m" (*p)
- );
- return res;
- }
- static inline int atomic_load_explicit(const volatile int* p, memory_order_acquire_t)
- {
- int res;
- __asm__ __volatile__
- (
- "ldar %w0, %w1\n\t"
- : "=r" (res)
- : "m" (*p)
- );
- return res;
- }
- static inline int atomic_load_explicit(const volatile int* p, int /* memory_order_seq_cst_t */)
- {
- int res;
- __asm__ __volatile__
- (
- "ldar %w0, %w1\n\t"
- : "=r" (res)
- : "m" (*p)
- );
- return res;
- }
- /*
- * native word support
- */
- static inline atomic_word atomic_load_explicit(const volatile atomic_word* p, memory_order_relaxed_t)
- {
- ATOMIC_LOAD("ldr")
- }
- static inline atomic_word atomic_load_explicit(const volatile atomic_word* p, memory_order_acquire_t)
- {
- ATOMIC_LOAD("ldar")
- }
- static inline atomic_word atomic_load_explicit(const volatile atomic_word* p, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_LOAD("ldar")
- }
- #define ATOMIC_STORE(opc) \
- __asm__ __volatile__ \
- ( \
- opc " %1, %0\n\t" \
- : "=m" (*p) \
- : "r" (v) \
- : "memory" \
- );
- /*
- * int support
- */
- static inline void atomic_store_explicit(volatile int* p, int v, memory_order_relaxed_t)
- {
- __asm__ __volatile__
- (
- "str %w1, %w0\n\t"
- : "=m" (*p)
- : "r" (v)
- : "memory"
- );
- }
- static inline void atomic_store_explicit(volatile int* p, int v, memory_order_release_t)
- {
- __asm__ __volatile__
- (
- "stlr %w1, %w0\n\t"
- : "=m" (*p)
- : "r" (v)
- : "memory"
- );
- }
- static inline void atomic_store_explicit(volatile int* p, int v, int /* memory_order_seq_cst_t */)
- {
- __asm__ __volatile__
- (
- "stlr %w1, %w0\n\t"
- : "=m" (*p)
- : "r" (v)
- : "memory"
- );
- }
- /*
- * native word support
- */
- static inline void atomic_store_explicit(volatile atomic_word* p, atomic_word v, memory_order_relaxed_t)
- {
- ATOMIC_STORE("str")
- }
- static inline void atomic_store_explicit(volatile atomic_word* p, atomic_word v, memory_order_release_t)
- {
- ATOMIC_STORE("stlr")
- }
- static inline void atomic_store_explicit(volatile atomic_word* p, atomic_word v, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_STORE("stlr")
- }
- #define ATOMIC_XCHG(LD, ST) \
- atomic_word res; \
- atomic_word success; \
- __asm__ __volatile__ \
- ( \
- "0:\n\t" \
- LD " %2, [%4]\n\t" \
- ST " %w0, %3, [%4]\n\t" \
- "cbnz %w0, 0b\n\t" \
- : "=&r" (success), "+m" (*p), "=&r" (res) \
- : "r" (v), "r" (p) \
- : "memory" \
- ); \
- return res;
- static inline atomic_word atomic_exchange_explicit(volatile atomic_word* p, atomic_word v, memory_order_relaxed_t)
- {
- ATOMIC_XCHG("ldxr", "stxr")
- }
- static inline atomic_word atomic_exchange_explicit(volatile atomic_word* p, atomic_word v, memory_order_acquire_t)
- {
- ATOMIC_XCHG("ldaxr", "stxr")
- }
- static inline atomic_word atomic_exchange_explicit(volatile atomic_word* p, atomic_word v, memory_order_release_t)
- {
- ATOMIC_XCHG("ldxr", "stlxr")
- }
- static inline atomic_word atomic_exchange_explicit(volatile atomic_word* p, atomic_word v, memory_order_acq_rel_t)
- {
- ATOMIC_XCHG("ldaxr", "stlxr")
- }
- static inline atomic_word atomic_exchange_explicit(volatile atomic_word* p, atomic_word v, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_XCHG("ldaxr", "stlxr")
- }
- // atomic_compare_exchange_weak_explicit: can fail spuriously even if *p == *oldval
- #define ATOMIC_CMP_XCHG(LD, ST) \
- atomic_word res; \
- atomic_word success = 0; \
- __asm__ __volatile__ \
- ( \
- LD " %2, [%4]\n\t" \
- "cmp %2, %5\n\t" \
- "b.ne 1f\n\t" \
- ST " %w0, %3, [%4]\n" \
- "1:\n\t" \
- "clrex\n\t" \
- : "=&r" (success), "+m" (*p), "=&r" (res) \
- : "r" (newval), "r" (p), "r" (*oldval) \
- : "cc", "memory" \
- ); \
- *oldval = res; \
- return success == 0;
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_relaxed_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldxr", "stxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acquire_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_release_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acq_rel_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, int /* memory_order_seq_cst_t */, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acquire_t, memory_order_acquire_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_release_t, memory_order_release_t)
- {
- ATOMIC_CMP_XCHG("ldxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acq_rel_t, memory_order_acq_rel_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_weak_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, int /* memory_order_seq_cst_t */, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- // atomic_compare_exchange_strong_explicit: does loop and only returns false if *p != *oldval
- #undef ATOMIC_CMP_XCHG
- #define ATOMIC_CMP_XCHG(LD, ST) \
- atomic_word res; \
- atomic_word success = 0; \
- __asm__ __volatile__ \
- ( \
- "0:\n\t" \
- LD " %2, [%4]\n\t" \
- "cmp %2, %5\n\t" \
- "b.ne 1f\n\t" \
- ST " %w0, %3, [%4]\n" \
- "cbnz %w0, 0b\n\t" \
- "1:\n\t" \
- "clrex\n\t" \
- : "=&r" (success), "+m" (*p), "=&r" (res) \
- : "r" (newval), "r" (p), "r" (*oldval) \
- : "cc", "memory" \
- ); \
- *oldval = res; \
- return success == 0;
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_relaxed_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldxr", "stxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acquire_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_release_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acq_rel_t, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, int /* memory_order_seq_cst_t */, memory_order_relaxed_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acquire_t, memory_order_acquire_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_release_t, memory_order_release_t)
- {
- ATOMIC_CMP_XCHG("ldxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, memory_order_acq_rel_t, memory_order_acq_rel_t)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word* p, atomic_word *oldval, atomic_word newval, int /* memory_order_seq_cst_t */, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_CMP_XCHG("ldaxr", "stlxr")
- }
- #define ATOMIC_PFIX_int "%w"
- #define ATOMIC_PFIX_atomic_word "%"
- #define ATOMIC_PFIX(WORD) ATOMIC_PFIX_##WORD
- #define ATOMIC_OP(WORD, LD, ST, OP) \
- long long res, tmp; \
- int success; \
- __asm__ __volatile__ \
- ( \
- "0:\n\t" \
- LD " " ATOMIC_PFIX(WORD) "2, [%5]\n\t" \
- OP " " ATOMIC_PFIX(WORD) "3, " ATOMIC_PFIX(WORD) "2, " ATOMIC_PFIX(WORD) "4\n\t"\
- ST " %w0, " ATOMIC_PFIX(WORD) "3, [%5]\n" \
- "cbnz %w0, 0b\n\t" \
- : "=&r" (success), "+m" (*p), "=&r" (res), "=&r" (tmp) \
- : "Ir" ((long long) v), "r" (p) \
- : "cc", "memory" \
- ); \
- return (WORD) res;
- static inline int atomic_fetch_add_explicit(volatile int* p, int v, memory_order_relaxed_t)
- {
- ATOMIC_OP(int, "ldxr", "stxr", "add")
- }
- static inline int atomic_fetch_add_explicit(volatile int* p, int v, memory_order_acquire_t)
- {
- ATOMIC_OP(int, "ldaxr", "stxr", "add")
- }
- static inline int atomic_fetch_add_explicit(volatile int* p, int v, memory_order_release_t)
- {
- ATOMIC_OP(int, "ldxr", "stlxr", "add")
- }
- static inline int atomic_fetch_add_explicit(volatile int* p, int v, memory_order_acq_rel_t)
- {
- ATOMIC_OP(int, "ldaxr", "stlxr", "add")
- }
- static inline int atomic_fetch_add_explicit(volatile int* p, int v, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_OP(int, "ldaxr", "stlxr", "add")
- }
- static inline atomic_word atomic_fetch_add_explicit(volatile atomic_word* p, atomic_word v, memory_order_relaxed_t)
- {
- ATOMIC_OP(atomic_word, "ldxr", "stxr", "add")
- }
- static inline atomic_word atomic_fetch_add_explicit(volatile atomic_word* p, atomic_word v, memory_order_acquire_t)
- {
- ATOMIC_OP(atomic_word, "ldaxr", "stxr", "add")
- }
- static inline atomic_word atomic_fetch_add_explicit(volatile atomic_word* p, atomic_word v, memory_order_release_t)
- {
- ATOMIC_OP(atomic_word, "ldxr", "stlxr", "add")
- }
- static inline atomic_word atomic_fetch_add_explicit(volatile atomic_word* p, atomic_word v, memory_order_acq_rel_t)
- {
- ATOMIC_OP(atomic_word, "ldaxr", "stlxr", "add")
- }
- static inline atomic_word atomic_fetch_add_explicit(volatile atomic_word* p, atomic_word v, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_OP(atomic_word, "ldaxr", "stlxr", "add")
- }
- static inline int atomic_fetch_sub_explicit(volatile int* p, int v, memory_order_relaxed_t)
- {
- ATOMIC_OP(int, "ldxr", "stxr", "sub")
- }
- static inline int atomic_fetch_sub_explicit(volatile int* p, int v, memory_order_acquire_t)
- {
- ATOMIC_OP(int, "ldaxr", "stxr", "sub")
- }
- static inline int atomic_fetch_sub_explicit(volatile int* p, int v, memory_order_release_t)
- {
- ATOMIC_OP(int, "ldxr", "stlxr", "sub")
- }
- static inline int atomic_fetch_sub_explicit(volatile int* p, int v, memory_order_acq_rel_t)
- {
- ATOMIC_OP(int, "ldaxr", "stlxr", "sub")
- }
- static inline int atomic_fetch_sub_explicit(volatile int* p, int v, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_OP(int, "ldaxr", "stlxr", "sub")
- }
- static inline atomic_word atomic_fetch_sub_explicit(volatile atomic_word* p, atomic_word v, memory_order_relaxed_t)
- {
- ATOMIC_OP(atomic_word, "ldxr", "stxr", "sub")
- }
- static inline atomic_word atomic_fetch_sub_explicit(volatile atomic_word* p, atomic_word v, memory_order_acquire_t)
- {
- ATOMIC_OP(atomic_word, "ldaxr", "stxr", "sub")
- }
- static inline atomic_word atomic_fetch_sub_explicit(volatile atomic_word* p, atomic_word v, memory_order_release_t)
- {
- ATOMIC_OP(atomic_word, "ldxr", "stlxr", "sub")
- }
- static inline atomic_word atomic_fetch_sub_explicit(volatile atomic_word* p, atomic_word v, memory_order_acq_rel_t)
- {
- ATOMIC_OP(atomic_word, "ldaxr", "stlxr", "sub")
- }
- static inline atomic_word atomic_fetch_sub_explicit(volatile atomic_word* p, atomic_word v, int /* memory_order_seq_cst_t */)
- {
- ATOMIC_OP(atomic_word, "ldaxr", "stlxr", "sub")
- }
- /*
- * extensions
- */
- static inline void atomic_retain(volatile int* p)
- {
- atomic_fetch_add_explicit(p, 1, memory_order_relaxed);
- }
- static inline bool atomic_release(volatile int* p)
- {
- bool res = atomic_fetch_sub_explicit(p, 1, memory_order_release) == 1;
- if (res)
- {
- atomic_thread_fence(memory_order_acquire);
- }
- return res;
- }
- /*
- * double word
- */
- // Note: the only way to get atomic 128-bit memory accesses on ARM64 is to use ldxp/stxp with a loop
- // (ldxp and stxp instructions are not guaranteed to appear atomic)
- static inline atomic_word2 atomic_load_explicit(const volatile atomic_word2* p, memory_order_relaxed_t)
- {
- atomic_word2 v;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldxp\t%1, %2, [%3]\n\t"
- "stxp\t%w0, %1, %2, [%3]\n\t"
- "cbnz\t%w0, 0b\n\t"
- : "=&r" (success), "=&r" (v.lo), "=&r" (v.hi)
- : "r" (p)
- );
- return v;
- }
- static inline atomic_word2 atomic_load_explicit(const volatile atomic_word2* p, memory_order_acquire_t)
- {
- atomic_word2 v;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldaxp\t%1, %2, [%3]\n\t"
- "stxp\t%w0, %1, %2, [%3]\n\t"
- "cbnz\t%w0, 0b\n\t"
- : "=&r" (success), "=&r" (v.lo), "=&r" (v.hi)
- : "r" (p)
- );
- return v;
- }
- static inline void atomic_store_explicit(volatile atomic_word2* p, atomic_word2 v, memory_order_relaxed_t)
- {
- atomic_word lo;
- atomic_word hi;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldxp\t%2, %3, [%6]\n\t"
- "stxp\t%w0, %4, %5, [%6]\n\t"
- "cbnz\t%w0, 0b\n\t"
- : "=&r" (success), "=m" (*p), "=&r" (lo), "=&r" (hi)
- : "r" (v.lo), "r" (v.hi), "r" (p)
- : "memory"
- );
- }
- static inline void atomic_store_explicit(volatile atomic_word2* p, atomic_word2 v, memory_order_release_t)
- {
- atomic_word lo;
- atomic_word hi;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldxp\t%2, %3, [%6]\n\t"
- "stlxp\t%w0, %4, %5, [%6]\n\t"
- "cbnz\t%w0, 0b\n\t"
- : "=&r" (success), "=m" (*p), "=&r" (lo), "=&r" (hi)
- : "r" (v.lo), "r" (v.hi), "r" (p)
- : "memory"
- );
- }
- static inline atomic_word2 atomic_exchange_explicit(volatile atomic_word2* p, atomic_word2 val, memory_order_acq_rel_t)
- {
- atomic_word2 oldval;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldaxp\t%2, %3, [%6]\n\t"
- "stlxp\t%w0, %5, %4, [%6]\n\t"
- "cbnz\t%w0, 0b\n\t"
- : "=&r" (success), "+m" (*p), "=&r" (oldval.lo), "=&r" (oldval.hi)
- : "r" (val.hi), "r" (val.lo), "r" (p)
- : "memory"
- );
- return oldval;
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word2* p, atomic_word2* oldval, atomic_word2 newval, memory_order_acquire_t, memory_order_relaxed_t)
- {
- atomic_word lo = oldval->lo;
- atomic_word hi = oldval->hi;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldaxp\t%2, %3, [%8]\n\t"
- "cmp\t%3, %5\n\t"
- "b.ne\t1f\n\t"
- "cmp\t%2, %4\n\t"
- "b.ne\t1f\n\t"
- "stxp\t%w0, %6, %7, [%8]\n\t"
- "cbnz\t%w0, 0b\n\t"
- "1:\n\t"
- "clrex\n\t"
- : "=&r" (success), "+m" (*p), "=&r" (oldval->lo), "=&r" (oldval->hi)
- : "r" (lo), "r" (hi), "r" (newval.lo), "r" (newval.hi), "r" (p), "0" (1)
- : "cc", "memory"
- );
- return success == 0;
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word2* p, atomic_word2* oldval, atomic_word2 newval, memory_order_release_t, memory_order_relaxed_t)
- {
- atomic_word lo = oldval->lo;
- atomic_word hi = oldval->hi;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldxp\t%2, %3, [%8]\n\t"
- "cmp\t%3, %5\n\t"
- "b.ne\t1f\n\t"
- "cmp\t%2, %4\n\t"
- "b.ne\t1f\n\t"
- "stlxp\t%w0, %6, %7, [%8]\n\t"
- "cbnz\t%w0, 0b\n\t"
- "1:\n\t"
- "clrex\n\t"
- : "=&r" (success), "+m" (*p), "=&r" (oldval->lo), "=&r" (oldval->hi)
- : "r" (lo), "r" (hi), "r" (newval.lo), "r" (newval.hi), "r" (p), "0" (1)
- : "cc", "memory"
- );
- return success == 0;
- }
- static inline bool atomic_compare_exchange_strong_explicit(volatile atomic_word2* p, atomic_word2* oldval, atomic_word2 newval, int /*memory_order_acq_rel_t*/, memory_order_relaxed_t)
- {
- atomic_word lo = oldval->lo;
- atomic_word hi = oldval->hi;
- atomic_word success;
- __asm__ __volatile__
- (
- "0:\n\t"
- "ldaxp\t%2, %3, [%8]\n\t"
- "cmp\t%3, %5\n\t"
- "b.ne\t1f\n\t"
- "cmp\t%2, %4\n\t"
- "b.ne\t1f\n\t"
- "stlxp\t%w0, %6, %7, [%8]\n\t"
- "cbnz\t%w0, 0b\n\t"
- "1:\n\t"
- "clrex\n\t"
- : "=&r" (success), "+m" (*p), "=&r" (oldval->lo), "=&r" (oldval->hi)
- : "r" (lo), "r" (hi), "r" (newval.lo), "r" (newval.hi), "r" (p), "0" (1)
- : "cc", "memory"
- );
- return success == 0;
- }
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