Merge pull request #21865 from rogday:nary_eltwise_layers

Reimplementation of Element-wise layers with broadcasting support

* init

* semi-working initial version

* add small_vector

* wip

* remove smallvec

* add nary function

* replace auto with Mat in lambda expr used in transform

* uncomment asserts

* autobuffer shape_buf & step_buf

* fix a missing bracket

* fixed a missing addLayer in parseElementWise

* solve one-dimensional broadcast

* remove pre_broadcast_transform for the case of two constants; fix missing constBlobsExtraInfo when addConstant is called

* one autobuffer for step & shape

* temporal fix for the missing original dimension information

* fix parseUnsqueeze when it gets a 1d tensor constant

* support sum/mean/min/max with only one input

* reuse old code to handle cases of two non-constant inputs

* add condition to handle div & mul of two non-constant inputs

* use || instead of or

* remove trainling spaces

* enlarge buf in binary_forward to contain other buffer

* use autobuffer in nary_forward

* generate data randomly and add more cases for perf

* add op and, or & xor

* update perf_dnn

* remove some comments

* remove legacy; add two ONNX conformance tests in filter

* move from cpu_denylist to all_denylist

* adjust parsing for inputs>=2

Co-authored-by: fengyuentau <yuantao.feng@opencv.org.cn>

modules/dnn/include/opencv2/dnn/all_layers.hpp

@@ -849,6 +849,12 @@ CV__DNN_INLINE_NS_BEGIN
         static Ptr<EltwiseLayerInt8> create(const LayerParams &params);
     };
 
+    class CV_EXPORTS NaryEltwiseLayer : public Layer
+    {
+    public:
+        static Ptr<NaryEltwiseLayer> create(const LayerParams &params);
+    };
+
     class CV_EXPORTS BatchNormLayer : public ActivationLayer
     {
     public: