CRIS atomics revisited 1/4: use need_atomic_barrier_p.

[Hans-Peter Nilsson]

Use the new need_atomic_barrier_p.

gcc:
        * config/cris/sync.md ("atomic_fetch_<atomic_op_name><mode>")
        ("atomic_compare_and_swap<mode>"): Gate expand_mem_thread_fence
        calls on result of call to need_atomic_barrier_p.

Index: config/cris/sync.md
===================================================================
--- config/cris/sync.md (revision 189499)
+++ config/cris/sync.md (working copy)
@@ -93,11 +93,15 @@ (define_expand "atomic_fetch_<atomic_op_
   if (<MODE>mode != QImode && TARGET_TRAP_UNALIGNED_ATOMIC)
     cris_emit_trap_for_misalignment (operands[1]);
 
-  expand_mem_thread_fence (mmodel);
+  if (need_atomic_barrier_p (mmodel, true))
+    expand_mem_thread_fence (mmodel);
+
   emit_insn (gen_cris_atomic_fetch_<atomic_op_name><mode>_1 (operands[0],
                                                             operands[1],
                                                             operands[2]));
-  expand_mem_thread_fence (mmodel);
+  if (need_atomic_barrier_p (mmodel, false))
+    expand_mem_thread_fence (mmodel);
+
   DONE;
 })
 
@@ -196,13 +200,17 @@ (define_expand "atomic_compare_and_swap<
   if (<MODE>mode != QImode && TARGET_TRAP_UNALIGNED_ATOMIC)
     cris_emit_trap_for_misalignment (operands[2]);
 
-  expand_mem_thread_fence (mmodel);
+  if (need_atomic_barrier_p (mmodel, true))
+    expand_mem_thread_fence (mmodel);
+
   emit_insn (gen_cris_atomic_compare_and_swap<mode>_1 (operands[0],
                                                       operands[1],
                                                       operands[2],
                                                       operands[3],
                                                       operands[4]));
-  expand_mem_thread_fence (mmodel);
+  if (need_atomic_barrier_p (mmodel, false))
+    expand_mem_thread_fence (mmodel);
+
   DONE;
 })
 
brgds, H-P