--- config/rs6000/rs6000.c	(revision 163943)
+++ config/rs6000/rs6000.c	(working copy)
@@ -10830,12 +10830,18 @@ rs6000_expand_ternop_builtin
       || arg2 == error_mark_node)
     return const0_rtx;
 
-  switch (icode)
+  /* Check and prepare argument depending on the instruction code.
+
+     Note that a switch statement instead of the sequence of tests
+     would be incorrect as many of the CODE_FOR values could be
+     CODE_FOR_nothing and that would yield multiple alternatives
+     with identical values.  We'd never reach here at runtime in
+     this case.  */
+  if (icode == CODE_FOR_altivec_vsldoi_v4sf
+      || icode == CODE_FOR_altivec_vsldoi_v4si
+      || icode == CODE_FOR_altivec_vsldoi_v8hi
+      || icode == CODE_FOR_altivec_vsldoi_v16qi)
     {
-    case CODE_FOR_altivec_vsldoi_v4sf:
-    case CODE_FOR_altivec_vsldoi_v4si:
-    case CODE_FOR_altivec_vsldoi_v8hi:
-    case CODE_FOR_altivec_vsldoi_v16qi:
       /* Only allow 4-bit unsigned literals.  */
       STRIP_NOPS (arg2);
       if (TREE_CODE (arg2) != INTEGER_CST
@@ -10844,16 +10850,16 @@
 	  error ("argument 3 must be a 4-bit unsigned literal");
 	  return const0_rtx;
 	}
-      break;
-
-    case CODE_FOR_vsx_xxpermdi_v2df:
-    case CODE_FOR_vsx_xxpermdi_v2di:
-    case CODE_FOR_vsx_xxsldwi_v16qi:
-    case CODE_FOR_vsx_xxsldwi_v8hi:
-    case CODE_FOR_vsx_xxsldwi_v4si:
-    case CODE_FOR_vsx_xxsldwi_v4sf:
-    case CODE_FOR_vsx_xxsldwi_v2di:
-    case CODE_FOR_vsx_xxsldwi_v2df:
+    }
+  else if (icode == CODE_FOR_vsx_xxpermdi_v2df
+           || icode == CODE_FOR_vsx_xxpermdi_v2di
+           || icode == CODE_FOR_vsx_xxsldwi_v16qi
+           || icode == CODE_FOR_vsx_xxsldwi_v8hi
+           || icode == CODE_FOR_vsx_xxsldwi_v4si
+           || icode == CODE_FOR_vsx_xxsldwi_v4sf
+           || icode == CODE_FOR_vsx_xxsldwi_v2di
+           || icode == CODE_FOR_vsx_xxsldwi_v2df)
+    {
       /* Only allow 2-bit unsigned literals.  */
       STRIP_NOPS (arg2);
       if (TREE_CODE (arg2) != INTEGER_CST
@@ -10862,10 +10868,10 @@
 	  error ("argument 3 must be a 2-bit unsigned literal");
 	  return const0_rtx;
 	}
-      break;
-
-    case CODE_FOR_vsx_set_v2df:
-    case CODE_FOR_vsx_set_v2di:
+    }
+  else if (icode == CODE_FOR_vsx_set_v2df
+           || icode == CODE_FOR_vsx_set_v2di)
+    {
       /* Only allow 1-bit unsigned literals.  */
       STRIP_NOPS (arg2);
       if (TREE_CODE (arg2) != INTEGER_CST
@@ -10874,10 +10880,6 @@
 	  error ("argument 3 must be a 1-bit unsigned literal");
 	  return const0_rtx;
 	}
-      break;
-
-    default:
-      break;
     }
 
   if (target == 0