Index: /trunk/source/level-0/ARM/arm-misc.lisp
===================================================================
--- /trunk/source/level-0/ARM/arm-misc.lisp	(revision 14652)
+++ /trunk/source/level-0/ARM/arm-misc.lisp	(revision 14653)
@@ -439,4 +439,5 @@
 (defarmlapfunction %atomic-decf-ptr ((ptr arg_z))
   (macptr-ptr imm1 ptr)
+  (dmb)
   @again
   (ldrex imm0 (:@ imm1))
@@ -489,4 +490,5 @@
   (cmp imm2 (:$ 0))
   (bne @again)
+  (dmb)
   (box-fixnum arg_z imm1)
   (bx lr)
@@ -854,4 +856,5 @@
   (cmp imm2 (:$ 0))
   (bne @again)
+  (dmb)
   (box-fixnum arg_z imm1)
   (bx lr))