configure: Check for __int128 type support

diff --git a/configure.ac b/configure.ac
index 73c2884..1cd4f24 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -697,6 +697,17 @@ AC_COMPILE_IFELSE(
        [AC_MSG_RESULT([no])]
 )
 
+AC_MSG_CHECKING([for __int128])
+AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+               [[#include <sys/types.h>]],
+               [[__int128 x = 0;
+                 return x;]])],
+       [AC_MSG_RESULT([yes]);
+        AC_DEFINE([HAVE_INT128], [], [have __int128 type support])],
+       [AC_MSG_RESULT([no])]
+)
+
 AC_MSG_CHECKING([for GCC __sync operations])
 AC_RUN_IFELSE([AC_LANG_SOURCE(
        [[