added fix for matmul and support for 6 rank tensor (#35740)

paddle/fluid/operators/matmul_op.cc

@@ -655,6 +655,24 @@ class MatMulOp : public framework::OperatorWithKernel {
           platform::errors::InvalidArgument("reshape_out supported rank is 3, "
                                             "received %d",
                                             reshape_out_size));
+
+      auto it = std::find(reshape_out.begin(), reshape_out.end(), -1);
+
+      // if "-1" is present then one of reshape dims must be infered
+      if (it != reshape_out.end()) {
+        int index = std::distance(reshape_out.begin(), it);
+
+        auto ddim_out_vec = framework::vectorize(ddim_out);
+
+        int ddim_out_product =
+            std::accumulate(ddim_out_vec.begin(), ddim_out_vec.end(), 1,
+                            std::multiplies<int>());
+        int reshape_out_product = std::accumulate(
+            reshape_out.begin(), reshape_out.end(), -1, std::multiplies<int>());
+
+        reshape_out[index] = ddim_out_product / reshape_out_product;
+      }
+
       framework::DDim shape_out =
           ddim_out.transpose(transpose_out).reshape(reshape_out);
       context->SetOutputDim("Out", shape_out);

paddle/fluid/platform/mkldnn_helper.h

@@ -358,6 +358,8 @@ inline MKLDNNMemoryFormat MKLDNNFormatForSize(size_t dims_size,
     } else if (data_format == MKLDNNMemoryFormat::nhwc) {
       return MKLDNNMemoryFormat::ndhwc;
     }
+  } else if (dims_size == 6) {
+    return MKLDNNMemoryFormat::abcdef;
   }
   return data_format;
 }