+#if defined(linux_HOST_OS ) || defined(freebsd_HOST_OS) || \
+ defined(dragonfly_HOST_OS) || defined(netbsd_HOST_OS ) || \
+ defined(openbsd_HOST_OS ) || \
+ ( defined(darwin_HOST_OS ) && !defined(powerpc_HOST_ARCH) )
+/* Don't use mmap on powerpc-apple-darwin as mmap doesn't support
+ * reallocating but we need to allocate jump islands just after each
+ * object images. Otherwise relative branches to jump islands can fail
+ * due to 24-bits displacement overflow.
+ */