sh.c (sh_expand_epilogue): Emit a blockage insn before cutting back the stack.

        * sh.c (sh_expand_epilogue): Emit a blockage insn before
        cutting back the stack.

From-SVN: r14362

diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
index fb723ba..30406f6 100644 (file)
--- a/gcc/config/sh/sh.c
+++ b/gcc/config/sh/sh.c
@@ -2705,15 +2705,24 @@ sh_expand_epilogue ()
 
   if (frame_pointer_needed)
     {
-      /* We deliberately make the add dependent on the frame_pointer,
-        to ensure that instruction scheduling won't move the stack pointer
-        adjust before instructions reading from the frame.  This can fail
-        if there is an interrupt which then writes to the stack.  */
       output_stack_adjust (get_frame_size (), frame_pointer_rtx, 7);
+
+      /* We must avoid moving the stack pointer adjustment past code
+        which reads from the local frame, else an interrupt could
+        occur after the SP adjustment and clobber data in the local
+        frame.  */
+      emit_insn (gen_blockage ());
       emit_insn (gen_movsi (stack_pointer_rtx, frame_pointer_rtx));
     }
-  else
-    output_stack_adjust (get_frame_size (), stack_pointer_rtx, 7);
+  else if (get_frame_size ())
+    {
+      /* We must avoid moving the stack pointer adjustment past code
+        which reads from the local frame, else an interrupt could
+        occur after the SP adjustment and clobber data in the local
+        frame.  */
+      emit_insn (gen_blockage ());
+      output_stack_adjust (get_frame_size (), stack_pointer_rtx, 7);
+    }
 
   /* Pop all the registers.  */