enhancement for linear backward data and weight
enhancement for linear backward data and weight

ktnyt/chainer,jnishi/chainer,tkerola/chainer,ronekko/chainer,okuta/chainer,jnishi/chainer,chainer/chainer,jnishi/chainer,chainer/chainer,anaruse/chainer,okuta/chainer,jnishi/chainer,hvy/chainer,niboshi/chainer,hvy/chainer,rezoo/chainer,wkentaro/chainer,chainer/chainer,ktnyt/chainer,okuta/chainer,keisuke-umezawa/chainer,keisuke-umezawa/chainer,hvy/chainer,niboshi/chainer,ktnyt/chainer,keisuke-umezawa/chainer,aonotas/chainer,wkentaro/chainer,okuta/chainer,hvy/chainer,wkentaro/chainer,chainer/chainer,niboshi/chainer,wkentaro/chainer,pfnet/chainer,ktnyt/chainer,niboshi/chainer,keisuke-umezawa/chainer