* add select_p

* fix bugs

* add custom test for select_p; modify select_p primrules

* modify according to xiaoxu's comment

* add eq_p, select_p, pow_p, use autograd to test grad of high order

* add requirement of autograd, modify expected type of eq

* modify according to xiaoxu's comment

* import primops to use primops.pow

* add log_p for auto_grad

* add log_p_op.cc in prim_op_test srcs

* fix bug of wrong op name; add test in test_primops

* add test case of log in testprimapi

* fix bug of test_without_guard

* no need to fix test_without_guard

* native commit for triple grad of sigmod

* Updated unittests files

* init functional jacobian api

* Updated trible_test func

* Updated gradient_checker & test_script

* finish test with dtype float32

* add float64 test case

* polish code

* use atol=1e-5 with dtype float64

* fix for ci

* set timeout for test_jacobian

* fix dygraph grad to support high differential

* polish API docstring

* Updated gradient checker and some related files

* fix double grad strip error for high differential

* fix double grad strip error for high differential

* Add Sigmoid triple grad tests

* fix dygraph double grad dtype error when calling for high differential senario

* Updated triple grad teses func

* Use np.random to initialize ddx

* Updated triple_grad_check func

* add todo for gradient checker and refine some comments

* remove additional code

* add test for warnging in backward.py

* format python code

* support multi input in triple gradient checker

* Add matmul triple grad kernel

* Updated comments of TODO

* Supported some special tests

* Change code-format to follow CI std

* Updated gradient_checker.py

* Fix conflicts

* Removed unnecessary printing log

* Change code style to follow CI std

* merge upstream

* add_p

* rm useless files

* add sub_p mul_p div_p

* add sqrt_p and tanh_p

* add reshape_p

* add broadcast_p

* add broadcast_p fill_constant_p matmul_p reduce_p reshape_p transpose_p

* add split_p and concat_p

* add gather_p and scatter_add_p

* add slice_select_p and slice_assign_p

* add multi input check for add_p, sub_p, mul_p, div_p

* update concat_p

* refine gather_p and scatter_add_p

* refine slice_assign_p and slice_select_p

* add 9 test for prim ops

* add more test and fix some bug

* add more test

* register proto

* add shape valid check for broadcast_p op, and add keepdim attr into reduce_p op proto

* support multi input and multi output for split_p and concat_p

* fix slice bug for slice_select_p and slice_assign_p

* dtype for axis attr should be long int

* update dtype for axis attr int64_t

* update for iscan CI

* add more shape and dtype check

* change IndexTensor into int32 dtype