Currently, the Galois Field multiplication tables are recalcuated
every time an encode is done. This is wasteful, as they are fixed
by k and m, which is set on init.
Calculate the tables only once, on init.
This trades off a little bit of per-context memory and creation
time for measurably faster encodes when using the same context.
On powerpc64le, when repeatedly encoding a 4kB file with pyeclib,
this increases the measured speed by over 10%.
Change-Id: I2f025aaee2d13cb1717a331e443e179ad5a13302
Signed-off-by: Daniel Axtens <dja@axtens.net>
90679884ef