[PATCH] x86: cmpxchg improvements

This adjusts i386's cmpxchg patterns so that

- for word and long cmpxchg-es the compiler can utilize all possible
  registers

- cmpxchg8b gets disabled when the minimum specified hardware architectur
  doesn't support it (like was already happening for the byte, word, and
  long ones).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index 2e3e8dbcb79f..35d3cff30057 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -424,6 +424,11 @@ config X86_POPAD_OK
         depends on !M386
         default y
 
+config X86_CMPXCHG64
+        bool
+        depends on !M386 && !M486
+        default y
+
 config X86_ALIGNMENT_16
         bool
         depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || X86_ELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODEGX1