diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -539,8 +539,7 @@
 	MPASS(pager_last < fs->first_object->size);
 
 	vm_fault_restore_map_lock(fs);
-	bdry_idx = (fs->entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
-	    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
+	bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(fs->entry);
 	if (fs->map->timestamp != fs->map_generation) {
 		if (bdry_idx == 0) {
 			vm_fault_populate_cleanup(fs->first_object, pager_first,
diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h
--- a/sys/vm/vm_map.h
+++ b/sys/vm/vm_map.h
@@ -154,8 +154,10 @@
 #define	MAP_ENTRY_HEADER		0x00080000
 
 #define	MAP_ENTRY_SPLIT_BOUNDARY_MASK	0x00300000
-
 #define	MAP_ENTRY_SPLIT_BOUNDARY_SHIFT	20
+#define	MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry)			\
+	(((entry)->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>	\
+	    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT)
 
 #ifdef	_KERNEL
 static __inline u_char
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -2449,8 +2449,7 @@
 	KASSERT(entry->end > startaddr && entry->start < startaddr,
 	    ("%s: invalid clip of entry %p", __func__, entry));
 
-	bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
-	    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
+	bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
 	if (bdry_idx != 0) {
 		if ((startaddr & (pagesizes[bdry_idx] - 1)) != 0)
 			return (KERN_INVALID_ARGUMENT);
@@ -2523,8 +2522,7 @@
 	KASSERT(entry->start < endaddr && entry->end > endaddr,
 	    ("%s: invalid clip of entry %p", __func__, entry));
 
-	bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
-	    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
+	bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
 	if (bdry_idx != 0) {
 		if ((endaddr & (pagesizes[bdry_idx] - 1)) != 0)
 			return (KERN_INVALID_ARGUMENT);
@@ -3516,8 +3514,7 @@
 			saved_start = entry->start;
 			saved_end = entry->end;
 			last_timestamp = map->timestamp;
-			bidx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
-			    >> MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
+			bidx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
 			incr =  pagesizes[bidx];
 			vm_map_busy(map);
 			vm_map_unlock(map);
@@ -3715,9 +3712,7 @@
 				vm_map_unlock_read(map);
 				return (KERN_INVALID_ARGUMENT);
 			}
-			bdry_idx = (entry->eflags &
-			    MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
-			    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
+			bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
 			if (bdry_idx != 0 &&
 			    ((start & (pagesizes[bdry_idx] - 1)) != 0 ||
 			    (end & (pagesizes[bdry_idx] - 1)) != 0)) {