fix(dnn): fix dnn run cd4 on cpu

GitOrigin-RevId: 5eae7496e58077d9f84feaf4283de7fd0c762a9b

dnn/include/megdnn/handle.h

@@ -26,6 +26,27 @@ public:
         ATLAS = 13,
         CAMBRICON = 12,
     };
+    static std::string handle_type_name(HandleType handle) {
+#define INSTANCE_HANDLE(name) \
+    case HandleType::name:    \
+        return #name
+
+        switch (handle) {
+            INSTANCE_HANDLE(NAIVE);
+            INSTANCE_HANDLE(FALLBACK);
+            INSTANCE_HANDLE(X86);
+            INSTANCE_HANDLE(ARM_COMMON);
+            INSTANCE_HANDLE(ARMV7);
+            INSTANCE_HANDLE(AARCH64);
+            INSTANCE_HANDLE(CUDA);
+            INSTANCE_HANDLE(ROCM);
+            INSTANCE_HANDLE(ATLAS);
+            INSTANCE_HANDLE(CAMBRICON);
+            default:
+                return "Unknown";
+        }
+#undef INSTANCE_HANDLE
+    }
 
     //! Device vendor
     enum class HandleVendorType : uint32_t {

dnn/src/common/relayout_format.cpp

@@ -395,9 +395,19 @@ void RelayoutFormat::deduce_format(TensorFormat src, TensorFormat& dst) {
         (
                 handle()->type() != Handle::HandleType::NAIVE &&
                 handle()->type() != Handle::HandleType::X86)) {
-        megdnn_throw(
-                "Dump with Image2DPack4TensorFormat is not available on CUDA compnode, "
-                "try export CUDA_VISIBLE_DEVICES=\'\'");
+        if (Handle::HandleType::CUDA == handle()->type()) {
+            megdnn_throw(
+                    "Dump with Image2DPack4TensorFormat is not available on CUDA "
+                    "compnode, "
+                    "try export CUDA_VISIBLE_DEVICES=\'\'");
+
+        } else {
+            auto handle_number = handle()->type();
+            megdnn_throw(ssprintf(
+                    "Dump with Image2DPack4TensorFormat is not available on %s "
+                    "compnode, try export %cGB_USE_%cEGDNN_DBG=2 ",
+                    Handle::handle_type_name(handle_number).c_str(), 'M', 'M'));
+        }
     }
 #undef CHECK_SRC
 }