* Create .gitattributes

* Update .gitattributes

* enable image storage test

* update swiftshader, use subzero backend, opt default

* darknet2ncnn: Add an option, which is enabled by default, to merge all yolo output into one layer. The convert result is compatible with yolov3 example and can be used in benchmark.

* Add darknet to ncnn converter with YOLOv4 support.

* darknet2ncnn: add copyright info, fix clang compatibility

* fix wrong target

* darknet2ncnn: compatible with clang++ 9.0.0

Co-authored-by: zcy6735 <zcy6735@arcsoft.com.cn>

* add mish layer

* add mish test

* wip

* wip

* fix

* image and imageview can not be destroyed until command execution ends

* fast copy path for tightly packed data

* wip

* texture load works

* 1d 3d image

* record clone image, multiple commands share one image reference

* upload download image

* layer forward accept vkimagemat

* vkimagemat graph works

* staging vkimagemat for passing dynamic parameters, macro for fp32+image shader, padding image shader

* vkimagemat elemsize

* convolution test pass

* conv1x1s1 image shader

* fast staging image allocator from host memory, pooling image shader

* convolutiondepthwise image shader

* innerproduct image shader

* packing image shader

* crop deconvolution image shader

* resolve spirv binding types

* image fp16 and fp16a, cast image shader

* eltwise image shader

* wip

* absval image shader

* deconvolutiondepthwise image shader

* concat image shader, squeezenet works

* noop split image shader

* uniform precision hint

* layer support_image_storage

* wip

* vulkan device utility operator

* command is storage and packing option aware

* fallback to cpu on image allocation failed, mobilenetssd works

* flatten image shader, enable more test

* ci test

* check imgfp32 imgfp16 imgfp16a features

* fix ci test

* fix ci test

* upgrade swiftshader

* wip

* opt aggressive

* imgfp16p

* opt none

* convolution winograd image shader

* fix flush range, fast copy path for continous buffer

* minor fix

* fix innerproduct

* wip ...

* wip

* cast fix

* packing test

* wip

* image fp16p is fp16p

* wip

* silence

* more line info

* code clean

* softmax image shader

Fix a bug in crop.cpp which may cause failure to crop layer

* fix #1701, #1697

* Update CMakeLists.txt

* vkmat and command api breaks

* always use compute queue for compute buffer transfer

* no barrier for readonly weight buffer

* record clone, drop queue_owner

* bring back layer forward

* fix validation errors

* lifecycle inside command makes life easier

* update doc

* record_import_android_hardware_buffer