diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 04a83735875fcebcbdabcb91a647ab07ef861181..170bfa54b04831e4f1bef16832a6a102612519b6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-05-31  Richard Earnshaw  <richard.earnshaw@arm.com>
+
+	* arm.c (arm_print_operand case 'S'): Validate that the operand is
+	a shift operand before calling shift_op.  Avoid redundant call of
+	shift_op.
+
 2006-05-30  Naveen.H.S  <naveenh@kpitcummins.com>
 	    DJ Delorie  <dj@redhat.com>
 
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index a26222a932b5ccd0f63759cf603c22d53ac25dc0..a36c0d791760a80f655959c86681fb9ef131945c 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -11013,11 +11013,19 @@ arm_print_operand (FILE *stream, rtx x, int code)
     case 'S':
       {
 	HOST_WIDE_INT val;
-	const char * shift = shift_op (x, &val);
+	const char *shift;
+
+	if (!shift_operator (x, SImode))
+	  {
+	    output_operand_lossage ("invalid shift operand");
+	    break;
+	  }
+
+	shift = shift_op (x, &val);
 
 	if (shift)
 	  {
-	    fprintf (stream, ", %s ", shift_op (x, &val));
+	    fprintf (stream, ", %s ", shift);
 	    if (val == -1)
 	      arm_print_operand (stream, XEXP (x, 1), 0);
 	    else