diff --git a/compiler/test/compilable/test22809.c b/compiler/test/compilable/test22809.c
index 1f41da0dad..68752d50a0 100644
--- a/compiler/test/compilable/test22809.c
+++ b/compiler/test/compilable/test22809.c
@@ -13,3 +13,17 @@ struct Foo {
 
 int y = ((size_t)((char *)&((struct Foo *)1)->x - (char *)1));
 _Static_assert(((size_t)((char *)&((struct Foo *)0)->y - (char *)0))==4, "");
+
+
+// https://issues.dlang.org/show_bug.cgi?id=23584
+
+int foo(float bar)
+{
+    return __builtin_bit_cast(unsigned int, bar);
+}
+
+void test23584()
+{
+    int i = foo(3.5);
+    _Static_assert(foo(3.5) == 0x40600000, "1");
+}
diff --git a/druntime/src/importc.h b/druntime/src/importc.h
index bcdfb8b5f2..d54ca1b1d6 100644
--- a/druntime/src/importc.h
+++ b/druntime/src/importc.h
@@ -71,6 +71,8 @@
  */
 #define __builtin_offsetof(t,i) ((typeof(sizeof(0)))((char *)&((t *)0)->i - (char *)0))
 
+#define __builtin_bit_cast(t,e) (*(t*)(void*)&(e))
+
 /***************************
  * C11 6.10.8.3 Conditional feature macros
  */