private void EventLayer_OnBackward(object sender, BackwardArgs <T> e)
{
int nCount = e.BottomVec[0].count();
long hTopDiff0 = e.TopVec[0].mutable_gpu_diff;
long hBottomData1 = e.BottomVec[1].gpu_data;
long hBottomDiff1 = e.BottomVec[1].mutable_gpu_diff;
long hBottomDiff = e.BottomVec[0].mutable_gpu_diff;
m_cuda.sign(nCount, hBottomData1, hBottomDiff1);
m_cuda.abs(nCount, hBottomDiff1, hBottomDiff1);
m_cuda.mul(nCount, hBottomDiff1, hTopDiff0, hBottomDiff);
}