diff --git a/ChangeLog b/ChangeLog
index cbec38c4da..751f71187a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Tue Nov 15 13:38:14 2011  Naohisa Goto  <ngotogenome@gmail.com>
+
+	* include/ruby/defines.h (FLUSH_REGISTER_WINDOWS): move sparc asm code
+	  to a separete file sparc.c for preventing inlining optimization.
+	  Patched by Jurij Smakov. [Bug #5244] [ruby-core:40685]
+	* sparc.c (rb_sparc_flush_register_windows): ditto.
+	* configure.in: ditto.
+
 Tue Nov 15 13:11:35 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* include/ruby/ruby.h: get rid of gcc specific rb_long2int(),
diff --git a/configure.in b/configure.in
index b1bc951e52..7f9066b161 100644
--- a/configure.in
+++ b/configure.in
@@ -1087,7 +1087,8 @@ AS_CASE(["$target_cpu"],
 			[CFLAGS="-mieee $CFLAGS"],
 		[osf*],    # ccc
 			[CFLAGS="-ieee $CFLAGS"],
-		)])
+		)],
+[sparc*], [AC_LIBOBJ([sparc])])
 
 ac_cv_header_net_socket_h=${ac_cv_header_net_socket_h=no}
 if test "$ac_cv_header_net_socket_h" = yes; then
diff --git a/include/ruby/defines.h b/include/ruby/defines.h
index 58336c1ebd..2ef26d0da8 100644
--- a/include/ruby/defines.h
+++ b/include/ruby/defines.h
@@ -198,21 +198,8 @@ void xfree(void*);
 #endif
 
 #if defined(__sparc)
-static inline void
-flush_register_windows(void)
-{
-    asm
-#ifdef __GNUC__
-	volatile
-#endif
-# if SIZEOF_VOIDP > 4		/* workaround for Debian Sparc quirk */
-	("flushw")
-# else
-	("ta 0x03")
-# endif /* trap always to flush register windows if we are on a Sparc system */
-	;
-}
-#  define FLUSH_REGISTER_WINDOWS flush_register_windows()
+void rb_sparc_flush_register_windows();
+#  define FLUSH_REGISTER_WINDOWS rb_sparc_flush_register_windows()
 #elif defined(__ia64)
 void *rb_ia64_bsp(void);
 void rb_ia64_flushrs(void);
diff --git a/sparc.c b/sparc.c
new file mode 100644
index 0000000000..b764e900d7
--- /dev/null
+++ b/sparc.c
@@ -0,0 +1,30 @@
+/********************************************************************
+ Flush register windows on sparc.
+
+ This function is in a separate file to prevent inlining. The "flushw"
+ assembler instruction used on sparcv9 flushes all register windows
+ except the current one, so if it is inlined, the current register
+ window of the process executing the instruction will not be flushed
+ correctly.
+
+ See http://redmine.ruby-lang.org/issues/5244 for discussion.
+*********************************************************************/
+void rb_sparc_flush_register_windows()
+{
+    asm
+#ifdef __GNUC__
+    __volatile__
+#endif
+
+/* This condition should be in sync with one in configure.in */
+#if defined(__sparcv9) || defined(__sparc_v9__) || defined(__arch64__)
+# ifdef __GNUC__
+    ("flushw" : : : "%o7")
+# else
+    ("flushw")
+# endif /* __GNUC__ */
+#else
+    ("ta 0x03")
+#endif
+    ;
+}