tree bdb7fc514599ac98f8c0b189c46543498e31d091
parent 2a1137753f9618283ac40394a75976d18f608e39
author Aurelien Jarno <aurelien@aurel32.net> 1383763881 +0100
committer Richard Henderson <rth@twiddle.net> 1390691959 -0800

tcg/i386: use movbe instruction in qemu_ldst routines

The movbe instruction has been added on some Intel Atom CPUs and on
recent Intel Haswell CPUs. It allows to load/store a value and at the
same time bswap it.

This patch detects the avaibility of this instruction and when available
use it in the qemu load/store routines in replacement of load/store +
bswap. Note that for 16-bit unsigned loads, movbe + movzw is basically the
same as movzw + bswap, so the patch doesn't touch this case.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
[RTH: Reduced the number of conditionals using "movop".]
Signed-off-by: Richard Henderson <rth@twiddle.net>