[PATCH] SPARC architecture optimizations

Hello Ruby-core,

 Can I request incorporation of this patch into the ruby_1_8 branch? 

 The patch concerns a performance enhancement for SPARC based systems, 
which I've tested, using self written tests and the Debian benchmarks.  
It removes some unnecessary register window flush calls, and gives 
between 5 and 13% improvement on SPARC - and does not affect other 
platforms.

 This patch is not directly applicable to Ruby 1.9, and the use of 
register window flushes seems limited to the gc and thread context 
related code - which are appropriate uses to flush register windows.

 Please find the patch inlined below -

Index: defines.h
===================================================================
--- defines.h   (revision 15899)
+++ defines.h   (working copy)
@@ -227,12 +227,18 @@
        ;
 }
 #  define FLUSH_REGISTER_WINDOWS flush_register_windows()
+#  define EXEC_FLUSH_REGISTER_WINDOWS ((void)0)
+#  define SWITCH_FLUSH_REGISTER_WINDOWS ((void)0)
 #elif defined(__ia64)
 void *rb_ia64_bsp(void);
 void rb_ia64_flushrs(void);
 #  define FLUSH_REGISTER_WINDOWS rb_ia64_flushrs()
+#  define EXEC_FLUSH_REGISTER_WINDOWS FLUSH_REGISTER_WINDOWS
+#  define SWITCH_FLUSH_REGISTER_WINDOWS FLUSH_REGISTER_WINDOWS
 #else
 #  define FLUSH_REGISTER_WINDOWS ((void)0)
+#  define EXEC_FLUSH_REGISTER_WINDOWS FLUSH_REGISTER_WINDOWS
+#  define SWITCH_FLUSH_REGISTER_WINDOWS FLUSH_REGISTER_WINDOWS
 #endif

 #if defined(DOSISH)
Index: eval.c
===================================================================
--- eval.c      (revision 15899)
+++ eval.c      (working copy)
@@ -1025,7 +1025,7 @@
 #define PROT_LAMBDA INT2FIX(2) /* 5 */
 #define PROT_YIELD  INT2FIX(3) /* 7 */

-#define EXEC_TAG()    (FLUSH_REGISTER_WINDOWS, ruby_setjmp(((void)0), 
prot_tag->buf))
+#define EXEC_TAG()    (EXEC_FLUSH_REGISTER_WINDOWS, 
ruby_setjmp(((void)0), prot_tag->buf))

 #define JUMP_TAG(st) do {              \
     ruby_frame = prot_tag->frame;      \
@@ -10330,7 +10330,7 @@
 }

 #define THREAD_SAVE_CONTEXT(th) \
-    (rb_thread_switch((FLUSH_REGISTER_WINDOWS, 
ruby_setjmp(rb_thread_save_context(th), (th)->context))))
+    (rb_thread_switch((SWITCH_FLUSH_REGISTER_WINDOWS, 
ruby_setjmp(rb_thread_save_context(th), (th)->context))))

 NORETURN(static void rb_thread_restore_context _((rb_thread_t,int)));
 NORETURN(NOINLINE(static void 
rb_thread_restore_context_0(rb_thread_t,int,void*)));


Thanks,
 -ps




Prashant Srinivasan wrote:
> Thomas Enebo wrote:
>> Someone at Sun has been looking at Ruby on Sparc:
>>
>> http://blogs.sun.com/d/entry/ruby_performance_gains_on_sparc
>>
>> Not sure if he has contacted any core devs about this so I thought I 
>> would forward the link.
>>
>
> Miriam and Darryl are in the compiler team at Sun - I gave their 
> changes a spin with some micro-benchmarks of my own + the Debian 
> benchmarks, and there are between 5-13% in optimizations to be had here.
>
> Looking at Darryl's blog entry, I see that Matz has expressed interest 
> in merging the |FLUSH_REGISTER_WINDOWS| changes - so Darryl may 
> already be in touch?
>
> -ps
>


-- 
Prashant Srinivasan
F/OSS Enthusiast
Sun Microsystems, Inc.
http://blogs.sun.com/prashant
GnuPG key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x82FBDE5A