Hello all,

Here is a cleaned up version of the previous experimental patch:
http://marc.info/?l=linux-bluetooth&m=123245036109697&w=2

I changed it to be alignment and byte order neutral (input data is read one
byte at a time). It's a bit slower than reading via int16_t * pointer, but
avoids headache of worrying about the other problems. Endian conversion
is still also kept (when reading one byte at a time, it does not affect
performance anyway).

The patch should be safe to apply.

Benchmarks show consistent performance improvement ~30% for both x86
and ARM Cortex-A8. It's even more than I measured before just because
optimizations are cumulative and the effect of each individual change becomes
more visible when the other parts also get faster (the previous benchmark was
run before "-funroll-loops" optimization got committed).

ARM Cortex-A8:

before:
real    1m 24.78s
user    1m 21.20s
sys     0m 3.57s

after:
real    1m 4.72s
user    1m 1.03s
sys     0m 3.68s

Intel Core2:

before:
real    0m10.210s
user    0m9.761s
sys     0m0.324s

after:
real    0m7.729s
user    0m7.268s
sys     0m0.376s


Best regards,
Siarhei Siamashka