From: @wuxuejian
Reviewed-by: @kisnwang,@c_34
Signed-off-by: @c_34

From: @yuanwei66
Reviewed-by: @liangchenghui,@wuxuejian
Signed-off-by:

From: @zhao_ting_v
Reviewed-by: @liangchenghui,@wuxuejian
Signed-off-by: @wuxuejian

From: @dangjiaqi1
Reviewed-by: 
Signed-off-by:

From: @d00562747
Reviewed-by: 
Signed-off-by:

From: @xuguoyang5566
Reviewed-by: 
Signed-off-by:

From: @xutianming1985
Reviewed-by: 
Signed-off-by:

From: @xiangyunwu21
Reviewed-by: 
Signed-off-by:

From: @yang_chun
Reviewed-by: @wuxuejian,@c_34
Signed-off-by: @c_34

From: @lishixing3
Reviewed-by: 
Signed-off-by:

From: @xukailun_1
Reviewed-by: 
Signed-off-by:

From: @he-botao
Reviewed-by: 
Signed-off-by:

From: @yuanwei66
Reviewed-by: 
Signed-off-by:

From: @anrui-wang
Reviewed-by: 
Signed-off-by:

Add select ops for cpu

Add select ops for cpu

Add select ops for cpu -- remove useless methods

Add select ops for cpu -- remove useless methods

Add select ops for cpu -- remove useless methods

From: @zhao_ting_v
Reviewed-by: @kisnwang,@wuxuejian
Signed-off-by: @liangchenghui

From: @xcnick
Reviewed-by: 
Signed-off-by:

Merge pull request !8088 from zhaoting/adam

Merge pull request !7808 from baihuawei/fixcpu

Merge pull request !7428 from wuxuejian/cpu_op

Merge pull request !7381 from zhaoting/master

Merge pull request !7693 from wanyiming/add_sigmoid_cross_entropy_with_logit_cpu

Merge pull request !7276 from baihuawei/conv2d