x86/boot: fold two MOVs into an ADD

There's no point going through %ax; the addition can be done directly in
%di.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>

diff --git a/xen/arch/x86/boot/mem.S b/xen/arch/x86/boot/mem.S
index a2db7b5d4d840e2ead35411b3b56f6da845a298f..94ffc87d500afe299307c119e2284046a0e9274a 100644 (file)
--- a/xen/arch/x86/boot/mem.S
+++ b/xen/arch/x86/boot/mem.S
@@ -24,9 +24,7 @@ get_memory_map:
         cmpw    $E820_BIOS_MAX, bootsym(bios_e820nr) # up to this many entries
         jae     .Ldone
 
-        movw    %di,%ax
-        addw    $20,%ax
-        movw    %ax,%di
+        addw    $20,%di
         testl   %ebx,%ebx                       # check to see if
         jnz     1b                              # %ebx is set to EOF