]> xenbits.xensource.com Git - xen.git/commit
x86/entry: Use 32bit xors rater than 64bit xors for clearing GPRs
authorAndrew Cooper <andrew.cooper3@citrix.com>
Wed, 14 Feb 2018 13:07:05 +0000 (13:07 +0000)
committerAndrew Cooper <andrew.cooper3@citrix.com>
Thu, 15 Feb 2018 11:08:27 +0000 (11:08 +0000)
commiteb1d3a3f04b85d596862a4c9dcf796e67ab4dc09
tree6cea69fbaf008da35f7a3a3dbc5c3540950f0ca2
parent27196d4cc917d91b5b5daee50173565139ca9c9d
x86/entry: Use 32bit xors rater than 64bit xors for clearing GPRs

Intel's Silvermont/Knights Landing architecture treats them as full ALU
operations, rather than zeroing idoms.

No functional change, and no change in code volume (only changing the bit
selection in the REX prefix).

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
xen/include/asm-x86/asm_defns.h