The well-known idiom to compute a required number of data blocks
of size B to contain data of length d is:
(d + (B-1))/B
The code we use, with ceill(), computes the same value, but does
it in an unorthodox way. This makes a reviewer to doubt himself
and even run tests to make sure we're really computing the
obvious thing.
Apropos the reviewer confusion, the code in Phazr.IO looks weird.
It uses (word_size - hamming_distance) to compute the necessary
number of blocks... but then returns the amount of memory needed
to store blocks of a different size (word_size). We left all of it
alone and return exactly the same values that the old computation
returned.
All these computations were the only thing in the code that used
-lm, so drop that too.
Coincidentially, this patch solves the crash of distro-built
packages of liberasurecode (see Red Hat bug #1454543). But it's
a side effect. Expect a proper patch soon.
Change-Id: Ib297f6df304abf5ca8c27d3392b1107a525e0be0
Pete Zaitcev