Merge branch 'main' into pytools-tag-for-instruction

Author: inducer

loopy/kernel/tools.py

@@ -1671,14 +1671,17 @@ def find_most_recent_global_barrier(kernel, insn_id):
     totally ordered within the kernel.
     """
 
-    global_barrier_order = get_global_barrier_order(kernel)
+    insn = kernel.id_to_insn[insn_id]
 
-    if len(global_barrier_order) == 0:
+    if len(insn.depends_on) == 0:
         return None
 
-    insn = kernel.id_to_insn[insn_id]
+    if all(not _is_global_barrier(kernel, insn.id) for insn in kernel.instructions):
+        return None
 
-    if len(insn.depends_on) == 0:
+    global_barrier_order = get_global_barrier_order(kernel)
+
+    if len(global_barrier_order) == 0:
         return None
 
     global_barrier_to_ordinal = {