x86-64: Don't generate cmov in vread_tsc
x86-64: Don't generate cmov in vread_tsc

vread_tsc checks whether rdtsc returns something less than
cycle_last, which is an extremely predictable branch.  GCC likes
to generate a cmov anyway, which is several cycles slower than
a predicted branch.  This saves a couple of nanoseconds.

Signed-off-by: Andy Lutomirski <2cc0d0d76de2e6f37b92deeb83c85cb306fc5dc1@mit.edu>
Cc: Andi Kleen <dbd122ef7b6a09ffecf5db9c9296320f3c94e707@firstfloor.org>
Cc: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>
Cc: "David S. Miller" <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>
Cc: Eric Dumazet <a0baddf32b28d2f9429941ed4af2fe636e210591@gmail.com>
Cc: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Cc: Borislav Petkov <0691a664b24b6f15b20cd5aee64b72271db08be1@amd64.org>
Link: http://lkml.kernel.org/r/%3C561280649519de41352fcb620684dfb22bad6bac.1306156808.git.luto%40mit.edu%3E
Signed-off-by: Thomas Gleixner <00e4cf8f46a57000a44449bf9dd8cbbcc209fd2a@linutronix.de>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs