Prevent aborts taking a vector mode subreg of a constant integer

From-SVN: r52467

gcc/ChangeLog

@@ -4,6 +4,10 @@
 	(handle_vector_size_attribute): Use it to avoid generating a
 	new type node each time we are called.
 
+	* combine.c (subst): Avoid trying to make a vector mode subreg of
+	an integer constant.
+	(gen_lowpart_for_combine): Likewise.
+			
 2002-04-18  Roger Sayle  <roger@eyesopen.com>
 	    Jakub Jelinek  <jakub@redhat.com>
 

gcc/combine.c

@@ -3538,6 +3538,9 @@ subst (x, from, to, in_dest, unique_copy)
 
 	      if (GET_CODE (new) == CONST_INT && GET_CODE (x) == SUBREG)
 		{
+		  if (VECTOR_MODE_P (GET_MODE (x)))
+		    return gen_rtx_CLOBBER (VOIDmode, const0_rtx);
+
 		  x = simplify_subreg (GET_MODE (x), new,
 				       GET_MODE (SUBREG_REG (x)),
 				       SUBREG_BYTE (x));
@@ -9800,6 +9803,12 @@ gen_lowpart_for_combine (mode, x)
 	    || GET_MODE_SIZE (GET_MODE (x)) == GET_MODE_SIZE (mode)))
     return gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
 
+  /* simplify_gen_subreg does not know how to handle the case where we try
+     to convert an integer constant to a vector.
+     ??? We could try to teach it to generate CONST_VECTORs.  */
+  if (GET_MODE (x) == VOIDmode && VECTOR_MODE_P (mode))
+    return gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
+
   /* X might be a paradoxical (subreg (mem)).  In that case, gen_lowpart
      won't know what to do.  So we will strip off the SUBREG here and
      process normally.  */