* hacking to support dot of 3 by 2 inputs with gemm_batch.

* clean up.

* testing inplace reshape.

* fixed a compile error.

* added comments on todo.

* check for output.

* check for annotation.

* more optimizations WIP.

* sum simd.

* moved parallel for

* testing sum vectorization.

* fixed merge errors.

* sum wip.

* more logic.

* sum refactor and clean up.

* clean up.

* removed unrelated changes.

* removed related changes from merge.

* fixed clang compile errors.