include: restore Intel intrinsics replacement for C11 atomics

include/vlc_atomic.h

@@ -27,12 +27,163 @@
  */
 
 # ifndef __cplusplus
-#  if (__STDC_VERSION__ >= 201112L) && defined(__STDC_NO_ATOMICS__)
-#   error Atomic operations required!
-#  endif
+#  if (__STDC_VERSION__ >= 201112L) && !defined (__STDC_NO_ATOMICS__)
 /*** Native C11 atomics ***/
 #   include <stdatomic.h>
 
+#  else
+/*** Intel/GCC atomics ***/
+
+#  define ATOMIC_FLAG_INIT false
+
+#  define ATOMIC_VAR_INIT(value) (value)
+
+#  define atomic_init(obj, value) \
+    do { *(obj) = (value); } while(0)
+
+#  define kill_dependency(y) \
+    ((void)0)
+
+#  define atomic_thread_fence(order) \
+    __sync_synchronize()
+
+#  define atomic_signal_fence(order) \
+    ((void)0)
+
+#  define atomic_is_lock_free(obj) \
+    false
+
+typedef          bool      atomic_flag;
+typedef          bool      atomic_bool;
+typedef          char      atomic_char;
+typedef   signed char      atomic_schar;
+typedef unsigned char      atomic_uchar;
+typedef          short     atomic_short;
+typedef unsigned short     atomic_ushort;
+typedef          int       atomic_int;
+typedef unsigned int       atomic_uint;
+typedef          long      atomic_long;
+typedef unsigned long      atomic_ulong;
+typedef          long long atomic_llong;
+typedef unsigned long long atomic_ullong;
+//typedef          char16_t  atomic_char16_t;
+//typedef          char32_t  atomic_char32_t;
+typedef          wchar_t   atomic_wchar_t;
+typedef       int_least8_t atomic_int_least8_t;
+typedef      uint_least8_t atomic_uint_least8_t;
+typedef      int_least16_t atomic_int_least16_t;
+typedef     uint_least16_t atomic_uint_least16_t;
+typedef      int_least32_t atomic_int_least32_t;
+typedef     uint_least32_t atomic_uint_least32_t;
+typedef      int_least64_t atomic_int_least64_t;
+typedef     uint_least64_t atomic_uint_least64_t;
+typedef       int_fast8_t atomic_int_fast8_t;
+typedef      uint_fast8_t atomic_uint_fast8_t;
+typedef      int_fast16_t atomic_int_fast16_t;
+typedef     uint_fast16_t atomic_uint_fast16_t;
+typedef      int_fast32_t atomic_int_fast32_t;
+typedef     uint_fast32_t atomic_uint_fast32_t;
+typedef      int_fast64_t atomic_int_fast64_t;
+typedef     uint_fast64_t atomic_uint_fast64_t;
+typedef          intptr_t atomic_intptr_t;
+typedef         uintptr_t atomic_uintptr_t;
+typedef            size_t atomic_size_t;
+typedef         ptrdiff_t atomic_ptrdiff_t;
+typedef          intmax_t atomic_intmax_t;
+typedef         uintmax_t atomic_uintmax_t;
+
+#  define atomic_store(object,desired) \
+    do { \
+        *(object) = (desired); \
+        __sync_synchronize(); \
+    } while (0)
+
+#  define atomic_store_explicit(object,desired,order) \
+    atomic_store(object,desired)
+
+#  define atomic_load(object) \
+    (__sync_synchronize(), *(object))
+
+#  define atomic_load_explicit(object,order) \
+    atomic_load(object)
+
+#  define atomic_exchange(object,desired) \
+({  \
+    typeof (object) _obj = (object); \
+    typeof (*object) _old; \
+    do \
+        _old = atomic_load(_obj); \
+    while (!__sync_bool_compare_and_swap(_obj, _old, (desired))); \
+    _old; \
+})
+
+#  define atomic_exchange_explicit(object,desired,order) \
+    atomic_exchange(object,desired)
+
+#  define atomic_compare_exchange(object,expected,desired) \
+({  \
+    typeof (object) _exp = (expected); \
+    typeof (*object) _old = *_exp; \
+    *_exp = __sync_val_compare_and_swap((object), _old, (desired)); \
+    *_exp == _old; \
+})
+
+#  define atomic_compare_exchange_strong(object,expected,desired) \
+    atomic_compare_exchange(object, expected, desired)
+
+#  define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
+    atomic_compare_exchange_strong(object, expected, desired)
+
+#  define atomic_compare_exchange_weak(object,expected,desired) \
+    atomic_compare_exchange(object, expected, desired)
+
+#  define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
+    atomic_compare_exchange_weak(object, expected, desired)
+
+#  define atomic_fetch_add(object,operand) \
+    __sync_fetch_and_add(object, operand)
+
+#  define atomic_fetch_add_explicit(object,operand,order) \
+    atomic_fetch_add(object,operand)
+
+#  define atomic_fetch_sub(object,operand) \
+    __sync_fetch_and_sub(object, operand)
+
+#  define atomic_fetch_sub_explicit(object,operand,order) \
+    atomic_fetch_sub(object,operand)
+
+#  define atomic_fetch_or(object,operand) \
+    __sync_fetch_and_or(object, operand)
+
+#  define atomic_fetch_or_explicit(object,operand,order) \
+    atomic_fetch_or(object,operand)
+
+#  define atomic_fetch_xor(object,operand) \
+    __sync_fetch_and_sub(object, operand)
+
+#  define atomic_fetch_xor_explicit(object,operand,order) \
+    atomic_fetch_sub(object,operand)
+
+#  define atomic_fetch_and(object,operand) \
+    __sync_fetch_and_and(object, operand)
+
+#  define atomic_fetch_and_explicit(object,operand,order) \
+    atomic_fetch_and(object,operand)
+
+#  define atomic_flag_test_and_set(object) \
+    atomic_exchange(object, true)
+
+#  define atomic_flag_test_and_set_explicit(object,order) \
+    atomic_flag_test_and_set(object)
+
+#  define atomic_flag_clear(object) \
+    atomic_store(object, false)
+
+#  define atomic_flag_clear_explicit(object,order) \
+    atomic_flag_clear(object)
+
+# endif /* !C11 */
+
 typedef atomic_uint_least32_t vlc_atomic_float;
 
 static inline void vlc_atomic_init_float(vlc_atomic_float *var, float f)