re PR bootstrap/59934 (Bootstrap fail since r206941: expmed.h:252:33: error:…

re PR bootstrap/59934 (Bootstrap fail since r206941: expmed.h:252:33: error: array subscript is above array bounds)

       PR bootstrap/59934
        * expmed.h (expmed_mode_index): Rework so that analysis and optimziers
        know when the MODE_PARTIAL_INT and MODE_VECTOR_INT cases can never be
        reached.

From-SVN: r207137

gcc/ChangeLog

+2014-01-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR bootstrap/59934
+	* expmed.h (expmed_mode_index): Rework so that analysis and optimziers
+	know when the MODE_PARTIAL_INT and MODE_VECTOR_INT cases can never be
+	reached.
+
 2014-01-27  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* common/config/arm/arm-common.c

gcc/expmed.h

@@ -221,12 +221,21 @@ expmed_mode_index (enum machine_mode mode)
     case MODE_INT:
       return mode - MIN_MODE_INT;
     case MODE_PARTIAL_INT:
-      return mode - MIN_MODE_PARTIAL_INT + NUM_MODE_INT;
+      /* If there are no partial integer modes, help the compiler
+	 to figure out this will never happen.  See PR59934.  */
+      if (MIN_MODE_PARTIAL_INT != VOIDmode)
+	return mode - MIN_MODE_PARTIAL_INT + NUM_MODE_INT;
+      break;
     case MODE_VECTOR_INT:
-      return mode - MIN_MODE_VECTOR_INT + NUM_MODE_IP_INT;
+      /* If there are no vector integer modes, help the compiler
+	 to figure out this will never happen.  See PR59934.  */
+      if (MIN_MODE_VECTOR_INT != VOIDmode)
+	return mode - MIN_MODE_VECTOR_INT + NUM_MODE_IP_INT;
+      break;
     default:
-      gcc_unreachable ();
+      break;
     }
+  gcc_unreachable ();
 }
 
 /* Return a pointer to a boolean contained in EOC indicating whether