diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index c71c453..42053ea 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -1199,6 +1199,10 @@
 (define_predicate "x86_64_const_vector_operand"
   (match_code "const_vector")
 {
+  if (mode == VOIDmode)
+    mode = GET_MODE (op);
+  else if (GET_MODE (op) != mode)
+    return false;
   if (GET_MODE_SIZE (mode) > UNITS_PER_WORD)
     return false;
   HOST_WIDE_INT val = ix86_convert_const_vector_to_integer (op, mode);