* add mean op, test=develop

* split forward and backward, test=develop

* add lookup_dequant_op

* enhance gather, lookup_table arm kernel uts

* enhance beam_search, beam_search_decoder, increment rigster

* add sequence_conv op and arm kernel

* add test, test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* modify code style. test=develop

* fix ut, test=develop

* delete unused code, test=develop

* Add reduce sum op test
test=develop

add gemm + relu6/leakyrelu fusion

- enhance interp InferShape

* Support bitman backend

[LITE][NPU] Add instance_norm op bridge and unit test, refine the registration of op bridges (#2747)

* [NPU] enhance unittest for shuffle_channel, unsqueeze, pool

test=develop

test=develop

test=develop

X86 and cuda compile simutaneously cmake ..  -DCMAKE_BUILD_TYPE=RelWithDebInfo  -DWITH_MKL=ON           -DLITE_WITH_CUDA=ON           -DWITH_MKLDNN=OFF           -DLITE_WITH_X86=ON           -DLITE_WITH_PROFILE=OFF          -DWITH_LITE=OFF           -DLITE_WITH_LIGHT_WEIGHT_FRAMEWORK=OFF           -DWITH_PYTHON=OFF           -DWITH_TESTING=ON           -DLITE_WITH_ARM=OFF           -DLITE_ON_TINY_PUBLISH=OFF           -DCUDNN_ROOT=/usr/local/cudnn/           -DLITE_BUILD_EXTRA=ON (#2708)

x86 and cuda compile simutaneously

test=develop

* Fix the compiling error which occurs when specify the ddk_root path and build for huawei NPU.

* Refine the registration of op bridges and make it similar to the registration of op and kernel.

* Refine the interfaces of the graph and node for op bridges, and support creating constant and data node automatically according to the attribute 'persistable' of the target tensor.

* Add the unit test of the scale and softmax op bridge for NPU.

test=develop

* Support multiple types for XPU and NPU op bridges

* Add lookup_table, gather, slice, stack and scale op bridges for supporting BERT

* Fix the definition of lookup_table kernel for X86

test=develop

* [XPU] elementwise_add unit test

* [XPU] softmax unit test

test=develop

test=develop

test=develop

* [XPU] add transpose bridge and unit test

test=develop

[LITE][NPU][XPU] Refine subgraph pass, and support NPU/XPU model generation at execution time (#2576)

* add arm split lod tensor, test=develop

* add arm merge lod tensor, test=develop

* update split merge lod tensor, test=develop

* add reduce_prob op, test=develop

* support mask_rcnn succeed, test=develop

* update concat and unsqueeze, test=develop

We have changed 11 arm_kernels into extra type in #2347 , which has caused test_compiling failure. In this PR , we move their 11 related arm_kernel_test into build_extra=ON

* Initial support for XPU
* Fix compiling errors of XPU
* Move XPU op kernel bridges from backends to kernels to fix deps order
* Change the namespace and directory of XPU bridges
* Add XPU SDK
* Fix header files and namespace of XPU SDK
* Add unit tests for relu and conv2d ops
* Restore the modification of paddle_api_test
* Supports simple model which contains only a relu layer
* Add compiling scripts for XPU
* Fix compiling errors of XPU
* Add comments for XPU LoadModel and BuildModel

* fix gemm_int8, gemv-int8 and conv-int8 math function, add float bias

* change conv impl

* neon int8 kernel support float bias

* arm compute kernel support float bias

* add math_test target

* add tensor utils for testing, fix sgemm ut error

* add gemm_int8 unit test, support float bias

* fix build script

* add conv compute unit test for arm

* fix build script, test=develop

* fix fp32 dw conv3x3s1, test=develop

* add fp32 dw conv3x3s1, test=develop

* add armv7 fp32 dw conv3x3s1, test=develop

* add fp32 depthwise conv3x3s2, test=develop

* fix fp32 conv3x3 depthwise build error, test=develop

* fix gemm_like conv trans weights error, test=develop

* fix int8 depthwise conv3x3 error, test=develop

* turn on all test for arm fp32 conv, test=develop

* fix int8 conv1x1 error

* fix int8 direct conv3x3s1 error, test=develop

* fix int8 direct conv3x3s2, test=develop

* turn on all test for arm int8 conv, test=develop

* fix int8 fc error, change mobilenetv1-int8 ground-truth result to fluid, test=develop

* remove debug info, strip ut binary, test=develop

* fix conv compute error, test=develop

* change Init() to ReInitWhenNeeded(), test=develop

* fix code style, test=develop

* remote engine_test, test=develop

* fix building server tests error, test=develop

* fix sdot clang build error, test=develop

* fix sgemm ut timeout error, test=develop

* fix clang build error, test=develop

* turn off math basic test due to ci time out, test=develop

* fix conv_int8 ut error, test=develop

* add unsqueeze and range op. modify concat op test=develop

* modify exception in range_test_x86