Make LIBOMP_USE_ITT_NOTIFY a setting that can be enabled or disabled

On Blue Gene/Q, having LIBOMP_USE_ITT_NOTIFY support compiled into a
statically-linked binary causes a failure at runtime because dlopen fails.
This patch changes LIBOMP_USE_ITT_NOTIFY to a cacheable configuration setting
that can be disabled.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D20517

llvm-svn: 270884

openmp/runtime/CMakeLists.txt

@@ -200,8 +200,9 @@ elseif("${libomp_build_type_lowercase}" STREQUAL "minsizerel")
   set(MINSIZEREL_BUILD TRUE)
 endif()
 
-# Include itt notify interface? Right now, always.
-set(LIBOMP_USE_ITT_NOTIFY TRUE)
+# Include itt notify interface?
+set(LIBOMP_USE_ITT_NOTIFY TRUE CACHE BOOL
+  "Enable ITT notify?")
 
 # normal, profile, stubs library.
 set(NORMAL_LIBRARY FALSE)
@@ -354,6 +355,7 @@ if(${LIBOMP_STANDALONE_BUILD})
   libomp_say("Build                -- ${LIBOMP_BUILD}")
   libomp_say("Use Stats-gathering  -- ${LIBOMP_STATS}")
   libomp_say("Use Debugger-support -- ${LIBOMP_USE_DEBUGGER}")
+  libomp_say("Use ITT notify       -- ${LIBOMP_USE_ITT_NOTIFY}")
   libomp_say("Use OMPT-support     -- ${LIBOMP_OMPT_SUPPORT}")
   if(${LIBOMP_OMPT_SUPPORT})
     libomp_say("Use OMPT-blame       -- ${LIBOMP_OMPT_BLAME}")

openmp/runtime/src/kmp_config.h.cmake

@@ -85,7 +85,7 @@
 #define KMP_ADJUST_BLOCKTIME 1
 #define BUILD_PARALLEL_ORDERED 1
 #define KMP_ASM_INTRINS 1
-#define USE_ITT_BUILD 1
+#define USE_ITT_BUILD LIBOMP_USE_ITT_NOTIFY
 #define INTEL_ITTNOTIFY_PREFIX __kmp_itt_
 #if ! KMP_MIC
 # define USE_LOAD_BALANCE 1

openmp/runtime/src/kmp_csupport.c

@@ -507,7 +507,7 @@ __kmpc_end_serialized_parallel(ident_t *loc, kmp_int32 global_tid)
 
    // we need to wait for the proxy tasks before finishing the thread
    if ( task_team != NULL && task_team->tt.tt_found_proxy_tasks )
-        __kmp_task_team_wait(this_thr, serial_team, NULL ); // is an ITT object needed here?
+        __kmp_task_team_wait(this_thr, serial_team USE_ITT_BUILD_ARG(NULL) ); // is an ITT object needed here?
    #endif
 
     KMP_MB();

openmp/runtime/src/kmp_runtime.c

@@ -3734,7 +3734,9 @@ __kmp_register_root( int initial_thread )
     /* prepare the master thread for get_gtid() */
     __kmp_gtid_set_specific( gtid );
 
+#if USE_ITT_BUILD
     __kmp_itt_thread_name( gtid );
+#endif /* USE_ITT_BUILD */
 
     #ifdef KMP_TDATA_GTID
         __kmp_gtid = gtid;
@@ -3908,7 +3910,7 @@ __kmp_unregister_root_current_thread( int gtid )
         // the runtime is shutting down so we won't report any events
         thread->th.ompt_thread_info.state = ompt_state_undefined;
 #endif
-        __kmp_task_team_wait(thread, team, NULL );
+        __kmp_task_team_wait(thread, team USE_ITT_BUILD_ARG(NULL));
    }
 #endif