arm.md (stack_tie): New insn.

* arm.md (stack_tie): New insn.  Use an idiom that the alias code
understands to be a memory clobber.
* arm.c (arm_expand_prologue): Use it.

From-SVN: r55486

gcc/ChangeLog

+2002-07-16  Richard Earnshaw  <rearnsha@arm.com>
+
+	* arm.md (stack_tie): New insn.  Use an idiom that the alias code
+	understands to be a memory clobber.
+	* arm.c (arm_expand_prologue): Use it.
+
 2002-07-16  Daniel Berlin  <dberlin@dberlin.org>
 
 	* ra-rewrite.c: #include reload.h, insn-config.h

gcc/config/arm/arm.c

@@ -8387,15 +8387,8 @@ arm_expand_prologue ()
 	 will prevent the scheduler from moving stores to the frame
 	 before the stack adjustment.  */
       if (frame_pointer_needed)
-	{
-	  rtx unspec = gen_rtx_UNSPEC (SImode,
-				       gen_rtvec (2, stack_pointer_rtx,
-						  hard_frame_pointer_rtx),
-				       UNSPEC_PRLG_STK);
-
-	  insn = emit_insn (gen_rtx_CLOBBER (VOIDmode,
-				      gen_rtx_MEM (BLKmode, unspec)));
-	}
+	insn = emit_insn (gen_stack_tie (stack_pointer_rtx,
+					 hard_frame_pointer_rtx));
     }
 
   /* If we are profiling, make sure no instructions are scheduled before

gcc/config/arm/arm.md

@@ -8883,6 +8883,16 @@
   [(set_attr "type" "store4")]
 )
 
+(define_insn "stack_tie"
+  [(set (mem:BLK (scratch))
+	(unspec:BLK [(match_operand:SI 0 "s_register_operand" "r")
+		     (match_operand:SI 1 "s_register_operand" "r")]
+		    UNSPEC_PRLG_STK))]
+  ""
+  ""
+  [(set_attr "length" "0")]
+)
+
 ;; Similarly for the floating point registers
 (define_insn "*push_fp_multi"
   [(match_parallel 2 "multi_register_push"