# V004. Diagnostics from the 64-bit rule set are not entirely accurate without the appropriate 64-bit compiler. Consider utilizing 64-bit compiler if possible.

When detecting issues of 64-bit code, it is 64-bit configuration of a project that the analyzer must always test. For it is 64-bit configuration where data types are correctly expanded and branches like "#ifdef WIN64" are selected, and so on. It is incorrect to try to detect issues of 64-bit code in a 32-bit configuration.

But sometimes it may be helpful to test the 32-bit configuration of a project. You can do it in case when there is no 64-bit configuration yet but you need to estimate the scope of work on porting the code to a 64-bit platform. In this case you can test a project in 32-bit mode. Testing the 32-bit configuration instead of the 64-bit one will show how many diagnostic warnings the analyzer will generate when testing the 64-bit configuration. Our experiments show that of course far not all the diagnostic warnings are generated when testing the 32-bit configuration. But about 95% of them in the 32-bit mode coincide with those in the 64-bit mode. It allows you to estimate the necessary scope of work.

Pay attention! Even if you correct all the errors detected when testing the 32-bit configuration of a project, you cannot consider the code fully compatible with 64-bit systems. You need to perform the final testing of the project in its 64-bit configuration.

The V004 message is generated only once for each project checked in the 32-bit configuration. The warning refers to the file which will be the first to be analyzed when checking the project. It is done for the purpose to avoid displaying a lot of similar warnings in the report.