Index: atomic.S
===================================================================
RCS file: /cvsroot/src/common/lib/libc/arch/i386/atomic/atomic.S,v
retrieving revision 1.20
diff -u -u -r1.20 atomic.S
--- atomic.S	18 Feb 2014 10:16:55 -0000	1.20
+++ atomic.S	22 Apr 2014 12:25:35 -0000
@@ -175,10 +175,11 @@
 	ret
 ENDLABEL(membar_sync_end)
 
-#ifdef _HARDKERNEL
 ENTRY(_atomic_cas_64)
+#ifdef _HARDKERNEL
 	pushf
 	cli
+#endif /* _HARDKERNEL */
 	pushl	%edi
 	pushl	%ebx
 	movl	12(%esp), %edi
@@ -195,7 +196,9 @@
 1:
 	popl	%ebx
 	popl	%edi
+#ifdef _HARDKERNEL
 	popf
+#endif /* _HARDKERNEL */
 	ret
 2:
 	movl	0(%edi), %eax
@@ -216,13 +219,16 @@
 	popl	%ebx
 	popl	%edi
 	ret
+#ifdef _HARDKERNEL
 #ifdef GPROF
 	.space	16, 0x90
 #else
 	.space	32, 0x90
 #endif
+#endif /* _HARDKERNEL */
 ENDLABEL(_atomic_cas_cx8_end)
 
+#ifdef _HARDKERNEL
 ENTRY(sse2_lfence)
 	lfence
 	ret
@@ -238,20 +244,6 @@
 	.long	.Lpatch1, .Lpatch2, .Lpatch3, .Lpatch4, .Lpatch5
 	.long	.Lpatch6, .Lpatch7, .Lpatch8, .Lpatch9, .Lpatch10
 	.long	.Lpatch12, .Lpatch13, .Lpatch14, .Lpatch15, 0
-#else
-ENTRY(_atomic_cas_64)
-	pushl	%edi
-	pushl	%ebx
-	movl	12(%esp), %edi
-	movl	16(%esp), %eax
-	movl	20(%esp), %edx
-	movl	24(%esp), %ebx
-	movl	28(%esp), %ecx
-	lock
-	cmpxchg8b (%edi)
-	popl	%ebx
-	popl	%edi
-	ret
 #endif	/* _HARDKERNEL */
 
 ALIAS(atomic_add_32,_atomic_add_32)
@@ -319,9 +311,15 @@
 ALIAS(atomic_cas_ulong_ni,_atomic_cas_32_ni)
 ALIAS(atomic_cas_ptr_ni,_atomic_cas_32_ni)
 
+#if __i586__	/* pentium or higher */
+ALIAS(atomic_cas_64,_atomic_cas_cx8)
+ALIAS(atomic_cas_64_ni,_atomic_cas_cx8)
+ALIAS(__sync_val_compare_and_swap_8,_atomic_cas_cx8)
+#else
 ALIAS(atomic_cas_64,_atomic_cas_64)
 ALIAS(atomic_cas_64_ni,_atomic_cas_64)
 ALIAS(__sync_val_compare_and_swap_8,_atomic_cas_64)
+#endif
 
 ALIAS(membar_consumer,_membar_consumer)
 ALIAS(membar_producer,_membar_producer)