some clean-up and new comments.
some clean-up and new comments.

ritsu1228/eigen,ritsu1228/eigen,ROCmSoftwarePlatform/hipeigen,TSC21/Eigen,pasuka/eigen,ritsu1228/eigen,pasuka/eigen,ROCmSoftwarePlatform/hipeigen,TSC21/Eigen,ROCmSoftwarePlatform/hipeigen,Zefz/eigen,pasuka/eigen,Zefz/eigen,toastedcrumpets/eigen,pasuka/eigen,pasuka/eigen,Zefz/eigen,ROCmSoftwarePlatform/hipeigen,Zefz/eigen,TSC21/Eigen,TSC21/Eigen,ritsu1228/eigen,toastedcrumpets/eigen,toastedcrumpets/eigen,ritsu1228/eigen,toastedcrumpets/eigen