About Linux under C compile error (warning) cast from ' void* ' to ' int ' loses precision

Char *ptr;  // then omit part of    the code if ((int) ptr==-1 )  // wrong Place  

The meaning of the sentence is from void* to int conversion loss Precision, I believe see explanation some people understand,

This problem only occurs on Linux with the X64 bit, because the pointer occupies 8 bytes on a 64-bit machine, and int occupies four bytes, so this problem occurs.

Workaround:

(long) ptr = =-1 just fine.

About Linux under C compile error (warning) cast from ' void* ' to ' int ' loses precision