diff --git a/ChangeLog b/ChangeLog
index 7f9e5f5f20..6a2b94dab3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Jul  2 17:06:23 2005  Tanaka Akira  <akr@m17n.org>
+
+       * defines.h (FLUSH_REGISTER_WINDOWS): defined for IA64.
+	 (flush_register_windows): declare flush_register_windows.
+
+       * eval.c (flush_register_windows): new function.
+
 Fri Jul  1 17:48:52 2005  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* bignum.c (get2comp): revert all prior changes, and calculate
diff --git a/defines.h b/defines.h
index b5d0ed6e1c..7b650c3a7c 100644
--- a/defines.h
+++ b/defines.h
@@ -224,6 +224,13 @@ flush_register_windows(void)
 	;
 }
 #  define FLUSH_REGISTER_WINDOWS flush_register_windows()
+#elif defined(__ia64__)
+void flush_register_windows(void)
+#  if ( __GNUC__ == 3 && __GNUC_MINOR__ > 0 ) || __GNUC__ > 3
+__attribute__ ((noinline))
+#  endif
+  ;
+#  define FLUSH_REGISTER_WINDOWS flush_register_windows()
 #else
 #  define FLUSH_REGISTER_WINDOWS ((void)0)
 #endif
diff --git a/eval.c b/eval.c
index 287d00bf40..d5529f08b4 100644
--- a/eval.c
+++ b/eval.c
@@ -12823,3 +12823,13 @@ rb_throw(tag, val)
     argv[1] = val;
     rb_f_throw(2, argv);
 }
+
+/* flush_register_windows must not be inlined because flushrs doesn't flush
+ * current frame in register stack. */
+#ifdef __ia64__
+void flush_register_windows(void)
+{
+    __asm__ ("flushrs");
+}
+#endif
+