re PR middle-end/21850 (misscompiling comparision from vector to integer)

	PR middle-end/21850
	* tree.c (get_unwidened): Stop at NOP_EXPR/CONVERT_EXPR that convert
	from vector types.

	* gcc.c-torture/execute/20050607-1.c: New test.

From-SVN: r100725

gcc/ChangeLog

+2005-06-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/21850
+	* tree.c (get_unwidened): Stop at NOP_EXPR/CONVERT_EXPR that convert
+	from vector types.
+
 2005-06-07  Diego Novillo  <dnovillo@redhat.com>
 
 	* tree-ssa-threadupdate.c (struct thread_stats_d): Declare.

gcc/testsuite/ChangeLog

+2005-06-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/21850
+	* gcc.c-torture/execute/20050607-1.c: New test.
+
 2005-06-07  Thomas Koenig  <Thomas.Koenig@online.de>
 
 	PR libfortran/21926

gcc/testsuite/gcc.c-torture/execute/20050607-1.c

+/* PR middle-end/21850 */
+
+extern void abort (void);
+
+typedef int V2SI __attribute__ ((vector_size (8)));
+
+int
+main (void)
+{
+#if (__INT_MAX__ == 2147483647) \
+    && (__LONG_LONG_MAX__ == 9223372036854775807LL)
+  if (((int)(long long)(V2SI){ 2, 2 }) != 2)
+    abort ();
+#endif
+  return 0;
+}

gcc/tree.c

@@ -4937,9 +4937,16 @@ get_unwidened (tree op, tree for_type)
   while (TREE_CODE (op) == NOP_EXPR
 	 || TREE_CODE (op) == CONVERT_EXPR)
     {
-      int bitschange
-	= TYPE_PRECISION (TREE_TYPE (op))
-	  - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
+      int bitschange;
+
+      /* TYPE_PRECISION on vector types has different meaning
+	 (TYPE_VECTOR_SUBPARTS) and casts from vectors are view conversions,
+	 so avoid them here.  */
+      if (TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == VECTOR_TYPE)
+	break;
+
+      bitschange = TYPE_PRECISION (TREE_TYPE (op))
+		   - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
 
       /* Truncations are many-one so cannot be removed.
 	 Unless we are later going to truncate down even farther.  */