diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c4f8b626fe21..8e2759752a01 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2006-01-04  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c/25559
+	* c-common.c (handle_vector_size_attribute): Reject zero vector size
+	as well as sizes not multiple of component size.
+
 	PR debug/25562
 	* function.c (instantiate_expr): New function.
 	(instantiate_decls_1, instantiate_decls): If DECL_HAS_VALUE_EXPR_P,
diff --git a/gcc/c-common.c b/gcc/c-common.c
index b25234594584..76e90962f9bc 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -5199,6 +5199,18 @@ handle_vector_size_attribute (tree *node, tree name, tree args,
       return NULL_TREE;
     }
 
+  if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1))
+    {
+      error ("vector size not an integral multiple of component size");
+      return NULL;
+    }
+
+  if (vecsize == 0)
+    {
+      error ("zero vector size");
+      return NULL;
+    }
+
   /* Calculate how many units fit in the vector.  */
   nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1);
   if (nunits & (nunits - 1))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e02c3c7a5104..23350e1ca554 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2006-01-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/25559
+	* gcc.dg/pr25559.c: New test.
+
 2006-01-03  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/25492
diff --git a/gcc/testsuite/gcc.dg/pr25559.c b/gcc/testsuite/gcc.dg/pr25559.c
new file mode 100644
index 000000000000..7879a1558b64
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr25559.c
@@ -0,0 +1,10 @@
+/* PR c/25559 */
+/* { dg-do compile } */
+
+#define vs(n) __attribute__((vector_size (n)))
+int vs (-1) a;			/* { dg-warning "attribute ignored" } */
+int vs (0) b;			/* { dg-error "zero vector size" } */
+int vs (1) c;			/* { dg-error "multiple of component size" } */
+int vs (sizeof (int) / 2) d;	/* { dg-error "multiple of component size" } */
+int vs (sizeof (int)) e;
+int vs (sizeof (int) * 2) f;