From 092c20cb19c128e1db2756d1829b95fb16f9939b Mon Sep 17 00:00:00 2001 From: Ed Schouten Date: Fri, 30 Dec 2011 01:37:25 +0000 Subject: [PATCH] Extend to support GCC 4.7's __atomic. The development version of GCC also supports an atomics interface similar to Clang's. Change the header file to work as follows: - __CLANG_ATOMICS: Use Clang's new atomics interface, - __GNUC_ATOMICS: Use GCC's new atomics interface, - else: fall back to GCC's __sync interface. --- include/stdatomic.h | 52 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 43 insertions(+), 9 deletions(-) diff --git a/include/stdatomic.h b/include/stdatomic.h index 031f724b63f8..5fd42249c680 100644 --- a/include/stdatomic.h +++ b/include/stdatomic.h @@ -35,13 +35,13 @@ #if __has_feature(cxx_atomic) #define __CLANG_ATOMICS -#elif defined(__GNUC__) +#elif __GNUC_PREREQ__(4, 7) #define __GNUC_ATOMICS -#else +#elif !defined(__GNUC__) #error "stdatomic.h does not support your compiler" #endif -#ifdef __GNUC_ATOMICS +#if !defined(__CLANG_ATOMICS) #define _Atomic(T) struct { volatile T __val; } #endif @@ -52,7 +52,7 @@ #if defined(__CLANG_ATOMICS) #define ATOMIC_VAR_INIT(value) (value) #define atomic_init(obj, value) __atomic_init(obj, value) -#elif defined(__GNUC_ATOMICS) +#else #define ATOMIC_VAR_INIT(value) { .__val = (value) } #define atomic_init(obj, value) do { \ (obj)->__val = (value); \ @@ -106,19 +106,28 @@ enum memory_order { #if defined(__CLANG_ATOMICS) #define atomic_thread_fence(order) __atomic_thread_fence(order) -#elif defined(__GNUC_ATOMICS) -#define atomic_thread_fence(order) __sync_synchronize() -#endif #define atomic_signal_fence(order) __asm volatile ("" : : : "memory"); +#elif defined(__GNUC_ATOMICS) +#define atomic_thread_fence(order) __atomic_thread_fence(order) +#define atomic_signal_fence(order) __atomic_signal_fence(order) +#else +#define atomic_thread_fence(order) __sync_synchronize() +#define atomic_signal_fence(order) __asm volatile ("" : : : "memory"); +#endif /* * 7.17.5 Lock-free property. */ #if defined(__CLANG_ATOMICS) -#define atomic_is_lock_free(obj) __atomic_is_lock_free(obj) +#define atomic_is_lock_free(obj) \ + __atomic_is_lock_free(obj) #elif defined(__GNUC_ATOMICS) -#define atomic_is_lock_free(obj) (sizeof((obj)->__val) <= sizeof(void *)) +#define atomic_is_lock_free(obj) \ + __atomic_is_lock_free(sizeof((obj)->__val)) +#else +#define atomic_is_lock_free(obj) \ + (sizeof((obj)->__val) <= sizeof(void *)) #endif /* @@ -199,6 +208,31 @@ typedef _Atomic(__uintmax_t) atomic_uintmax_t; #define atomic_store_explicit(object, desired, order) \ __atomic_store(object, desired, order) #elif defined(__GNUC_ATOMICS) +#define atomic_compare_exchange_strong_explicit(object, expected, \ + desired, success, failure) \ + __atomic_compare_exchange_n(&(object)->__val, expected, \ + desired, 0, success, failure) +#define atomic_compare_exchange_weak_explicit(object, expected, \ + desired, success, failure) \ + __atomic_compare_exchange_n(&(object)->__val, expected, \ + desired, 1, success, failure) +#define atomic_exchange_explicit(object, desired, order) \ + __atomic_exchange_n(&(object)->__val, desired, order) +#define atomic_fetch_add_explicit(object, operand, order) \ + __atomic_fetch_add(&(object)->__val, operand, order) +#define atomic_fetch_and_explicit(object, operand, order) \ + __atomic_fetch_and(&(object)->__val, operand, order) +#define atomic_fetch_or_explicit(object, operand, order) \ + __atomic_fetch_or(&(object)->__val, operand, order) +#define atomic_fetch_sub_explicit(object, operand, order) \ + __atomic_fetch_sub(&(object)->__val, operand, order) +#define atomic_fetch_xor_explicit(object, operand, order) \ + __atomic_fetch_xor(&(object)->__val, operand, order) +#define atomic_load_explicit(object, order) \ + __atomic_load_n(&(object)->__val, order) +#define atomic_store_explicit(object, desired, order) \ + __atomic_store_n(&(object)->__val, desired, order) +#else #define atomic_compare_exchange_strong_explicit(object, expected, \ desired, success, failure) ({ \ __typeof__((object)->__val) __v; \