commit 082d4df76017763c6f5115ef613e6ed22cfea5ea
author Debargha Mukherjee <debargha@google.com> Thu Mar 16 07:10:41 2017 -0700
committer Debargha Mukherjee <debargha@google.com> Fri Mar 17 16:45:42 2017 +0000
tree 9e2fd9ab5994f713b6bf1df157ad929ef4475421
parent c45213ce81808d7ba0a1eef2a37c8908eeb3034f

Replace division in warped motion least squares

Replaces the int64 and int32 divisions in least-squares and
gamma or delta computation with a mechanism that decomposes
the divisor D such that 1/D = y * 2^-k where y is obtained
from a lookup table indexed by 8 highest bits of the difference
D - 2^floor(log2(D)). The main complexity is now only from
computing this decomposition, which is essentially equivalent
to finding floor(log2(D)) (position of highest
bit in a 64-bit integer).

Also includes an out of memory bug fix and some cleanups.

Change-Id: I9247fdff5f6b4191175d4b4656357bfff626f02c