From 780620e796f281b81f58a7236df1435dfc6b9a1e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= <markus.makela@mariadb.com>
Date: Tue, 12 Jun 2018 08:56:28 +0300
Subject: [PATCH] Only use __atomic builtins

Now that the compiler for CentOS 6 was upgraded, there is no need to
support the old __sync builtins.
---
 server/core/atomic.cc | 91 -------------------------------------------
 1 file changed, 91 deletions(-)

diff --git a/server/core/atomic.cc b/server/core/atomic.cc
index afb9cbc74..c7850ccf3 100644
--- a/server/core/atomic.cc
+++ b/server/core/atomic.cc
@@ -19,182 +19,91 @@
 
 int atomic_add(int *variable, int value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_fetch_add(variable, value, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_add(variable, value);
-#endif
 }
 
 uint32_t atomic_add_uint32(uint32_t *variable, int32_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_fetch_add(variable, value, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_add(variable, value);
-#endif
 }
 
 int64_t atomic_add_int64(int64_t *variable, int64_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_fetch_add(variable, value, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_add(variable, value);
-#endif
 }
 
 uint64_t atomic_add_uint64(uint64_t *variable, int64_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_fetch_add(variable, value, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_add(variable, value);
-#endif
 }
 
 int atomic_load_int(const int *variable)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_load_n(variable, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_or((int*)variable, 0);
-#endif
 }
 
 int32_t atomic_load_int32(const int32_t *variable)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_load_n(variable, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_or((int32_t*)variable, 0);
-#endif
 }
 
 int64_t atomic_load_int64(const int64_t *variable)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_load_n(variable, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_or((int64_t*)variable, 0);
-#endif
 }
 
 uint32_t atomic_load_uint32(const uint32_t *variable)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_load_n(variable, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_or((uint32_t*)variable, 0);
-#endif
 }
 
 uint64_t atomic_load_uint64(const uint64_t *variable)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_load_n(variable, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_or((uint64_t*)variable, 0);
-#endif
 }
 
 void* atomic_load_ptr(void * const *variable)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_load_n(variable, __ATOMIC_SEQ_CST);
-#else
-    return __sync_fetch_and_or((void **)variable, 0);
-#endif
 }
 
 void atomic_store_int(int *variable, int value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     __atomic_store_n(variable, value, __ATOMIC_SEQ_CST);
-#else
-    __sync_synchronize();
-    *variable = value;
-    __sync_synchronize();
-#endif
 }
 
 void atomic_store_int32(int32_t *variable, int32_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     __atomic_store_n(variable, value, __ATOMIC_SEQ_CST);
-#else
-    __sync_synchronize();
-    *variable = value;
-    __sync_synchronize();
-#endif
 }
 
 void atomic_store_int64(int64_t *variable, int64_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     __atomic_store_n(variable, value, __ATOMIC_SEQ_CST);
-#else
-    __sync_synchronize();
-    *variable = value;
-    __sync_synchronize();
-#endif
 }
 
 void atomic_store_uint32(uint32_t *variable, uint32_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     __atomic_store_n(variable, value, __ATOMIC_SEQ_CST);
-#else
-    __sync_synchronize();
-    *variable = value;
-    __sync_synchronize();
-#endif
 }
 
 void atomic_store_uint64(uint64_t *variable, uint64_t value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     __atomic_store_n(variable, value, __ATOMIC_SEQ_CST);
-#else
-    __sync_synchronize();
-    *variable = value;
-    __sync_synchronize();
-#endif
 }
 
 void atomic_store_ptr(void **variable, void *value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     __atomic_store_n(variable, value, __ATOMIC_SEQ_CST);
-#else
-    __sync_synchronize();
-    *variable = value;
-    __sync_synchronize();
-#endif
 }
 
 bool atomic_cas_ptr(void **variable, void** old_value, void *new_value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_compare_exchange_n(variable, old_value, new_value,
                                        false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
-#else
-    return __sync_bool_compare_and_swap(variable, *old_value, new_value);
-#endif
 }
 
 int atomic_exchange_int(int *variable, int new_value)
 {
-#ifdef MXS_USE_ATOMIC_BUILTINS
     return __atomic_exchange_n(variable, new_value, __ATOMIC_SEQ_CST);
-#else
-    /* The __sync-functions have a questionable exchange-operation (__sync_lock_test_and_set) which
-     * doesn't always write the requested value. Using compare-and-swap instead. */
-    int old_val = *variable;
-    while (!__sync_bool_compare_and_swap(variable, old_val, new_value))
-    {
-        old_val = *variable;
-    }
-    return old_val;
-#endif
 }
\ No newline at end of file