pnnx support torch-2.1 (#5074)

.ci/pnnx.yml

@@ -48,6 +48,10 @@ jobs:
             torchvision-version: 0.15.1
             torchvision-cache-key: '0_15_1'
 
+          - torch-version: 2.1.0
+            torchvision-version: 0.16.0
+            torchvision-cache-key: '0_16_0'
+
     runs-on:
       pool-name: docker
       container:

tools/pnnx/CMakeLists.txt

@@ -70,6 +70,11 @@ if(Torch_VERSION VERSION_LESS "1.8")
     message(FATAL_ERROR "pnnx only supports PyTorch >= 1.8")
 endif()
 
+if(Torch_VERSION VERSION_GREATER_EQUAL "2.1")
+    # c++17 is required for using torch 2.1+ headers
+    set(CMAKE_CXX_STANDARD 17)
+endif()
+
 if(TorchVision_FOUND)
     message(STATUS "Building with TorchVision")
     add_definitions(-DPNNX_TORCHVISION)

tools/pnnx/src/main.cpp

@@ -300,6 +300,11 @@ int main(int argc, char** argv)
         fprintf(stderr, "\n");
     }
 
+#ifdef PNNX_TORCHVISION
+    // call some vision api to register vision ops  :P
+    (void)vision::cuda_version();
+#endif
+
     for (auto m : customop_modules)
     {
         fprintf(stderr, "load custom module %s\n", m.c_str());

tools/pnnx/src/pass_level2/F_scaled_dot_product_attention.cpp

@@ -42,4 +42,31 @@ pnnx.Output             output      1 0 out
 
 REGISTER_GLOBAL_PNNX_GRAPH_REWRITER_PASS(F_scaled_dot_product_attention, 10)
 
+class F_scaled_dot_product_attention_1 : public GraphRewriterPass
+{
+public:
+    const char* match_pattern_graph() const
+    {
+        return R"PNNXIR(7767517
+9 8
+pnnx.Input              input_0     0 1 query
+pnnx.Input              input_1     0 1 key
+pnnx.Input              input_2     0 1 value
+pnnx.Input              input_3     0 1 attn_mask
+prim::Constant          op_0        0 1 dropout_p value=%dropout_p
+prim::Constant          op_1        0 1 is_causal value=%is_causal
+prim::Constant          op_2        0 1 scale value=%scale
+aten::scaled_dot_product_attention  op_3 7 1 query key value attn_mask dropout_p is_causal scale out
+pnnx.Output             output      1 0 out
+)PNNXIR";
+    }
+
+    const char* type_str() const
+    {
+        return "F.scaled_dot_product_attention";
+    }
+};
+
+REGISTER_GLOBAL_PNNX_GRAPH_REWRITER_PASS(F_scaled_dot_product_attention_1, 10)
+
 } // namespace pnnx