Merge pull request Sandia-OpenSHMEM#1136 from davidozog/pr/stride_zer…

…o_fix Teams: allow split stride of zero iff size is 1
davidozog · Jun 18, 2024 · f3689bb · f3689bb
2 parents cca11d0 + e61852e
commit f3689bb
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Showing 3 changed files with 6 additions and 5 deletions.
diff --git a/modules/tests-sos b/modules/tests-sos
diff --git a/src/shmem_internal.h b/src/shmem_internal.h
@@ -650,7 +650,8 @@ void shmem_internal_bit_to_string(char *str, size_t str_size,
 static inline
 int shmem_internal_pe_in_active_set(int global_pe, int PE_start, int PE_stride, int PE_size)
 {
-    shmem_internal_assert(PE_stride != 0);
+    if (PE_size == 1) return PE_start == global_pe ? 0 : -1;
+    if (PE_stride == 0) return -1;
     int n = (global_pe - PE_start) / PE_stride;
     if ((global_pe < PE_start && PE_stride > 0) || (global_pe > PE_start && PE_stride < 0) ||
         (global_pe - PE_start) % PE_stride || n >= PE_size)

diff --git a/src/shmem_team.c b/src/shmem_team.c
@@ -303,7 +303,7 @@ int shmem_internal_team_split_strided(shmem_internal_team_t *parent_team, int PE
 
     if (PE_start < 0 || PE_start >= parent_team->size ||
         PE_size <= 0 || PE_size > parent_team->size   ||
-        PE_stride == 0) {
+        (PE_stride == 0 && PE_size != 1)) {
         RAISE_WARN_MSG("Invalid <start, stride, size>: child <%d, %d, %d>, parent <%d, %d, %d>\n",
                        PE_start, PE_stride, PE_size,
                        parent_team->start, parent_team->stride, parent_team->size);
@@ -332,7 +332,7 @@ int shmem_internal_team_split_strided(shmem_internal_team_t *parent_team, int PE
 
         myteam->my_pe       = my_pe;
         myteam->start       = global_PE_start;
-        myteam->stride      = PE_stride;
+        myteam->stride      = (PE_stride == 0 || PE_size == 1) ? 1 : PE_stride;
         myteam->size        = PE_size;
 
         if (config_mask == 0) {
@@ -424,7 +424,7 @@ int shmem_internal_team_split_strided(shmem_internal_team_t *parent_team, int PE
     /* If no team was available, print some team triplet info and return nonzero. */
     if (my_pe >= 0 && myteam != NULL && myteam->psync_idx == -1) {
         RAISE_WARN_MSG("Team split strided failed: child <%d, %d, %d>, parent <%d, %d, %d>\n",
-                        global_PE_start, PE_stride, PE_size,
+                        myteam->start, myteam->stride, myteam->size,
                         parent_team->start, parent_team->stride, parent_team->size);
     }
     return *team_ret_val_reduced;