x86_64: Fix fp-to-core conversion

Long max value cannot be represented with double precision
and check fp against max_long does not guard invocation of
conversion instruction. As a result conversion ends up with
min long instead of max long.

The patch changes the guard check to not allow conversion
instruction for max long.

Change-Id: Ied761051ec27cf6c833040c25a2c61ab9fcea414
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>
3 files changed