opal/thread: Added keyword opal_thread_local for TLS.

configure: add checks for `__thread` on top of current check for `_Thread_local` and define OPAL_HAVE_THREAD_LOCAL if the compiler support TLS.

Added `opal_thread_local` keyword to unify the definition.

Signed-off-by: Thananon Patinyasakdikul <thananon.patinyasakdikul@intel.com>

config/opal_setup_cc.m4

@@ -46,7 +46,7 @@ AC_DEFUN([OPAL_PROG_CC_C11_HELPER],[
     opal_prog_cc_c11_helper_CFLAGS_save=$CFLAGS
     CFLAGS="$CFLAGS $1"
 
-    OPAL_CC_HELPER([if $CC $1 supports C11 thread local storage], [opal_prog_cc_c11_helper__Thread_local_available],
+    OPAL_CC_HELPER([if $CC $1 supports C11 _Thread_local], [opal_prog_cc_c11_helper__Thread_local_available],
                    [],[[static _Thread_local int  foo = 1;++foo;]], [OPAL_C_HAVE__THREAD_LOCAL],
                    [Whether C compiler supports __Thread_local])
 
@@ -160,6 +160,13 @@ AC_DEFUN([OPAL_SETUP_CC],[
         OPAL_PROG_CC_C11_HELPER([],[],[])
     fi
 
+    # Check if compiler support __thread
+    OPAL_VAR_SCOPE_PUSH([opal_prog_cc__thread_available])
+    OPAL_CC_HELPER([if $CC $1 supports __thread], [opal_prog_cc__thread_available],
+               [],[[static __thread int  foo = 1;++foo;]], [OPAL_C_HAVE___THREAD],
+               [Whether C compiler supports __thread])
+    OPAL_VAR_SCOPE_POP
+
     OPAL_C_COMPILER_VENDOR([opal_c_vendor])
 
     # Check for standard headers, needed here because needed before

opal/threads/thread_usage.h

@@ -249,4 +249,18 @@ OPAL_THREAD_DEFINE_ATOMIC_SWAP(int64_t, int64_t, 64)
 
 #endif
 
+/* thread local storage */
+#if OPAL_C_HAVE__THREAD_LOCAL
+#define opal_thread_local _Thread_local
+#define OPAL_HAVE_THREAD_LOCAL 1
+
+#elif OPAL_C_HAVE___THREAD /* OPAL_C_HAVE__THREAD_LOCAL */
+#define opal_thread_local __thread
+#define OPAL_HAVE_THREAD_LOCAL 1
+#endif /* OPAL_C_HAVE___THREAD */
+
+#if !defined(OPAL_HAVE_THREAD_LOCAL)
+#define OPAL_HAVE_THREAD_LOCAL 0
+#endif /* !defined(OPAL_HAVE_THREAD_LOCAL) */
+
 #endif /* !defined(OPAL_THREAD_USAGE_H) */