make notes more clear and accurate

mindspore/ccsrc/ir/dtype/type_id.h

@@ -19,6 +19,9 @@
 #ifndef MINDSPORE_CCSRC_IR_DTYPE_TYPE_ID_H_
 #define MINDSPORE_CCSRC_IR_DTYPE_TYPE_ID_H_
 
+#include <unordered_map>
+#include <string>
+
 namespace mindspore {
 //
 // Supported meta type
@@ -77,5 +80,12 @@ enum TypeId : int {
   kNumberTypeFloat64,
   kNumberTypeEnd
 };
+//
+// TypeId name map
+//
+const std::unordered_map<TypeId, std::string> type_name_map = {
+  {kNumberTypeBool, "Bool"},       {kNumberTypeInt8, "Int8"},       {kNumberTypeUInt8, "UInt8"},
+  {kNumberTypeInt16, "Int16"},     {kNumberTypeInt32, "Int32"},     {kNumberTypeInt64, "Int64"},
+  {kNumberTypeFloat16, "Float16"}, {kNumberTypeFloat32, "Float32"}, {kNumberTypeFloat64, "Float64"}};
 }  // namespace mindspore
 #endif  // MINDSPORE_CCSRC_IR_DTYPE_TYPE_ID_H_

mindspore/ccsrc/operator/composite/do_signature.cc

@@ -215,15 +215,21 @@ void DoAutoCast(const std::string &func_name, const std::vector<Signature> &sign
     TypeId arg_type_id = kTypeUnknown;
     AbstractBasePtr arg_value = args_spec_list[i];
     (void)GetTensorOrScalarTypeInfo(arg_value, is_write, &arg_type_id);
-    auto it_map = type_map.find(arg_type_id);
-    if (it_map == type_map.end()) {
+    auto it_map = type_name_map.find(arg_type_id);
+    if (it_map == type_name_map.end()) {
       continue;
     }
     if (is_write) {
       if (arg_type_id != it->second) {
-        MS_LOG(EXCEPTION) << "In op '" << func_name << "', argument '" << args_spec_list[i]
-                          << "' can not cast type from '" << TypeIdLabel(arg_type_id) << "' to '"
-                          << TypeIdLabel(it->second) << "' automatically.";
+        auto it_name_map = type_name_map.find(it->second);
+        if (it_name_map == type_name_map.end()) {
+          continue;
+        }
+        MS_LOG(EXCEPTION) << "In op '" << func_name << "', \n"
+                          << "the type of writable argument is '" << it_map->second << "', "
+                          << "but the largest type in the same SignatureEumDtype is '" << it_name_map->second
+                          << "'. The writable arg type is not equal to the largest type, "
+                          << "so can not cast automatically.";
       }
       continue;
     }