diff --git a/gcc/gimple-range-fold.cc b/gcc/gimple-range-fold.cc
index d8497fc9be7..3543f0980b8 100644
--- a/gcc/gimple-range-fold.cc
+++ b/gcc/gimple-range-fold.cc
@@ -1032,10 +1032,7 @@ fold_using_range::range_of_builtin_int_call (irange &r, gcall *call,
 	    if (tmp.get_signbit ().varying_p ())
 	      return false;
 	    if (tmp.get_signbit ().yes_p ())
-	      {
-		tree one = build_one_cst (type);
-		r.set (one, one);
-	      }
+	      r.set_nonzero (type);
 	    else
 	      r.set_zero (type);
 	    return true;
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-signbit-2.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-signbit-2.c
new file mode 100644
index 00000000000..954c7ebd4f8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-signbit-2.c
@@ -0,0 +1,24 @@
+// { dg-do compile }
+// { dg-options "-O2 -fdump-tree-evrp" }
+
+// Test that the only thing we know about the signbit about negative number is
+// that it's not 0.
+
+void link_error ();
+
+int num;
+
+void func(float x)
+{
+  if (x < -5.0)
+    {
+      num = __builtin_signbit (x);
+
+      // We may not know the exact signbit, but we know it's not 0.
+      if (!__builtin_signbit (x))
+	link_error ();
+    }
+}
+
+// { dg-final { scan-tree-dump-not "num = \[-0-9\];" "evrp" } }
+// { dg-final { scan-tree-dump-not "link_error" "evrp" } }