[OpenMP] Remove unused variables from libomp code

Several variables were left unused as a result of different patches removing
their use.

Two variables have some use:
`poll_count` is used by the KMP_BLOCKING macro only under certain conditions.
Adding (void) to tell the compiler to ignore the unused variable.

`padding` is a dummy stack allocation with no intent to be used. Also adding
(void) to make the compiler ignore the unused variable.

Differential Revision: https://reviews.llvm.org/D104303

openmp/runtime/cmake/LibompHandleFlags.cmake

@@ -35,7 +35,7 @@ function(libomp_get_cxxflags cxxflags)
   libomp_append(flags_local -Wno-stringop-truncation LIBOMP_HAVE_WNO_STRINGOP_TRUNCATION_FLAG)
   libomp_append(flags_local -Wno-switch LIBOMP_HAVE_WNO_SWITCH_FLAG)
   libomp_append(flags_local -Wno-uninitialized LIBOMP_HAVE_WNO_UNINITIALIZED_FLAG)
-  libomp_append(flags_local -Wno-unused-but-set-variable LIBOMP_HAVE_WNO_UNUSED_BUT_SET_VARIABLE_FLAG)
+  # libomp_append(flags_local -Wno-unused-but-set-variable LIBOMP_HAVE_WNO_UNUSED_BUT_SET_VARIABLE_FLAG)
   libomp_append(flags_local -Wno-return-type-c-linkage LIBOMP_HAVE_WNO_RETURN_TYPE_C_LINKAGE_FLAG)
   libomp_append(flags_local -Wno-cast-qual LIBOMP_HAVE_WNO_CAST_QUAL_FLAG)
   libomp_append(flags_local -Wno-int-to-void-pointer-cast LIBOMP_HAVE_WNO_INT_TO_VOID_POINTER_CAST_FLAG)

openmp/runtime/src/kmp_affinity.cpp

@@ -2608,12 +2608,6 @@ restart_radix_check:
   nCoresPerPkg = maxCt[coreIdIndex];
   nPackages = totals[pkgIdIndex];
 
-  // Check to see if the machine topology is uniform
-  unsigned prod = totals[maxIndex];
-  for (index = threadIdIndex; index < maxIndex; index++) {
-    prod *= maxCt[index];
-  }
-
   // When affinity is off, this routine will still be called to set
   // __kmp_ncores, as well as __kmp_nThreadsPerCore, nCoresPerPkg, & nPackages.
   // Make sure all these vars are set correctly, and return now if affinity is

openmp/runtime/src/kmp_csupport.cpp

@@ -2519,12 +2519,6 @@ void __kmpc_destroy_lock(ident_t *loc, kmp_int32 gtid, void **user_lock) {
   if (!codeptr)
     codeptr = OMPT_GET_RETURN_ADDRESS(0);
   if (ompt_enabled.ompt_callback_lock_destroy) {
-    kmp_user_lock_p lck;
-    if (KMP_EXTRACT_D_TAG(user_lock) == 0) {
-      lck = ((kmp_indirect_lock_t *)KMP_LOOKUP_I_LOCK(user_lock))->lock;
-    } else {
-      lck = (kmp_user_lock_p)user_lock;
-    }
     ompt_callbacks.ompt_callback(ompt_callback_lock_destroy)(
         ompt_mutex_lock, (ompt_wait_id_t)(uintptr_t)user_lock, codeptr);
   }

openmp/runtime/src/kmp_ftn_entry.h

@@ -128,12 +128,10 @@ int FTN_STDCALL FTN_GET_BLOCKTIME(void) {
   return __kmps_get_blocktime();
 #else
   int gtid, tid;
-  kmp_info_t *thread;
   kmp_team_p *team;
 
   gtid = __kmp_entry_gtid();
   tid = __kmp_tid_from_gtid(gtid);
-  thread = __kmp_thread_from_gtid(gtid);
   team = __kmp_threads[gtid]->th.th_team;
 
   /* These must match the settings used in __kmp_wait_sleep() */

openmp/runtime/src/kmp_lock.cpp

@@ -1091,7 +1091,6 @@ __kmp_acquire_queuing_lock_timed_template(kmp_queuing_lock_t *lck,
   volatile kmp_int32 *head_id_p = &lck->lk.head_id;
   volatile kmp_int32 *tail_id_p = &lck->lk.tail_id;
   volatile kmp_uint32 *spin_here_p;
-  kmp_int32 need_mf = 1;
 
 #if OMPT_SUPPORT
   ompt_state_t prev_state = ompt_state_undefined;
@@ -1142,7 +1141,6 @@ __kmp_acquire_queuing_lock_timed_template(kmp_queuing_lock_t *lck,
                 if ( t > 0 ) condition in the enqueued case below, which is not
                 necessary for this state transition */
 
-      need_mf = 0;
       /* try (-1,0)->(tid,tid) */
       enqueued = KMP_COMPARE_AND_STORE_ACQ64((volatile kmp_int64 *)tail_id_p,
                                              KMP_PACK_64(-1, 0),
@@ -1164,7 +1162,6 @@ __kmp_acquire_queuing_lock_timed_template(kmp_queuing_lock_t *lck,
       if (tail == 0) {
         enqueued = FALSE;
       } else {
-        need_mf = 0;
         /* try (h,t) or (h,h)->(h,tid) */
         enqueued = KMP_COMPARE_AND_STORE_ACQ32(tail_id_p, tail, gtid + 1);
 

openmp/runtime/src/kmp_runtime.cpp

@@ -1133,7 +1133,6 @@ void __kmp_serialized_parallel(ident_t *loc, kmp_int32 global_tid) {
 
 #if OMPT_SUPPORT
   ompt_data_t ompt_parallel_data = ompt_data_none;
-  ompt_data_t *implicit_task_data;
   void *codeptr = OMPT_LOAD_RETURN_ADDRESS(global_tid);
   if (ompt_enabled.enabled &&
       this_thr->th.ompt_thread_info.state != ompt_state_overhead) {
@@ -1326,7 +1325,6 @@ void __kmp_serialized_parallel(ident_t *loc, kmp_int32 global_tid) {
     // don't use lw_taskteam after linking. content was swaped
 
     /* OMPT implicit task begin */
-    implicit_task_data = OMPT_CUR_TASK_DATA(this_thr);
     if (ompt_enabled.ompt_callback_implicit_task) {
       ompt_callbacks.ompt_callback(ompt_callback_implicit_task)(
           ompt_scope_begin, OMPT_CUR_TEAM_DATA(this_thr),

openmp/runtime/src/kmp_wait_release.h

@@ -179,7 +179,6 @@ __kmp_wait_template(kmp_info_t *this_thr,
   kmp_uint32 spins;
   int th_gtid;
   int tasks_completed = FALSE;
-  int oversubscribed;
 #if !KMP_USE_MONITOR
   kmp_uint64 poll_count;
   kmp_uint64 hibernate_goal;
@@ -321,10 +320,10 @@ final_spin=FALSE)
     } else
       hibernate_goal = KMP_NOW() + this_thr->th.th_team_bt_intervals;
     poll_count = 0;
+    (void)poll_count;
 #endif // KMP_USE_MONITOR
   }
 
-  oversubscribed = (TCR_4(__kmp_nth) > __kmp_avail_proc);
   KMP_MB();
 
   // Main wait spin loop

openmp/runtime/src/z_Linux_util.cpp

@@ -515,6 +515,7 @@ static void *__kmp_launch_worker(void *thr) {
     KMP_OS_OPENBSD
   if (__kmp_stkoffset > 0 && gtid > 0) {
     padding = KMP_ALLOCA(gtid * __kmp_stkoffset);
+    (void)padding;
   }
 #endif