optimize bias accumulation in avx backend (#427)
optimize bias accumulation in avx backend (#427)

* optimize bias accumulation in avx backend

* follow new coding rule (spaces < 80)

* Revert "follow new coding rule (spaces < 80)"

This reverts commit 71bbe17e44cbdbf1b909cecdab345aafdee0690b.

* follow new coding rule (80 characters per line rule)

* use static_cast instead of C-style cast.

Wangyida/tiny-cnn,Wangyida/tiny-cnn